161 results on '"Eliot M, Rosen"'
Search Results
2. Supplementary Figure Legends 1-9 from Low Concentrations of Diindolylmethane, a Metabolite of Indole-3-Carbinol, Protect against Oxidative Stress in a BRCA1-Dependent Manner
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Eliot M. Rosen, Fazlul H. Sarkar, Tapas Saha, Qinghui Meng, and Saijun Fan
- Abstract
Supplementary Figure Legends 1-9 from Low Concentrations of Diindolylmethane, a Metabolite of Indole-3-Carbinol, Protect against Oxidative Stress in a BRCA1-Dependent Manner
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- 2023
3. Supplementary Table 1 from BRCA1 Induces Antioxidant Gene Expression and Resistance to Oxidative Stress
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Eliot M. Rosen, Anil K. Jaiswal, Itzhak D. Goldberg, Jingwen Xu, Hyo Jin Kang, Hee Jong Kim, Jeong Keun Rih, Qinghui Meng, Saijun Fan, and Insoo Bae
- Abstract
Supplementary Table 1 from BRCA1 Induces Antioxidant Gene Expression and Resistance to Oxidative Stress
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- 2023
4. Data from BRCA1 Induces Antioxidant Gene Expression and Resistance to Oxidative Stress
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Eliot M. Rosen, Anil K. Jaiswal, Itzhak D. Goldberg, Jingwen Xu, Hyo Jin Kang, Hee Jong Kim, Jeong Keun Rih, Qinghui Meng, Saijun Fan, and Insoo Bae
- Abstract
Mutations of the breast cancer susceptibility gene 1 (BRCA1), a tumor suppressor, confer an increased risk for breast, ovarian, and prostate cancers. To investigate the function of the BRCA1 gene, we performed DNA microarray and confirmatory reverse transcription-PCR analyses to identify BRCA1-regulated gene expression changes. We found that BRCA1 up-regulates the expression of multiple genes involved in the cytoprotective antioxidant response, including glutathione S-transferases, oxidoreductases, and other antioxidant genes. Consistent with these findings, BRCA1 overexpression conferred resistance while BRCA1 deficiency conferred sensitivity to several different oxidizing agents (hydrogen peroxide and paraquat). In addition, in the setting of oxidative stress (due to hydrogen peroxide), BRCA1 shifted the cellular redox balance to a higher ratio of reduced to oxidized glutathione. Finally, BRCA1 stimulated antioxidant response element-driven transcriptional activity and enhanced the activity of the antioxidant response transcription factor nuclear factor erythroid-derived 2 like 2 [also called NRF2 (NFE2L2)]. The ability of BRCA1 to stimulate antioxidant response element-dependent transcription and to protect cells against oxidative stress was attenuated by inhibition of nuclear factor erythroid-derived 2 like 2. These findings suggest a novel function for BRCA1, i.e., to protect cells against oxidative stress. This function would be consistent with the postulated role of BRCA1 as a caretaker gene in preserving genomic integrity.
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- 2023
5. EGFR-dependent Impact of Indol-3-Carbinol on Radiosensitivity of Lung Cancer Cells
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Xiao XIAO, Qinghui MENG, Jiaying XU, Yang JIAO, Eliot M ROSEN, and Saijun FAN
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Indol-3-carbinol ,Lung neoplasms ,Radiosensitivity ,Epidermal growth factor receptor ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and objective Indole-3-carbinol (I3C) is a naturally occurring phytochemical found in cruciferous vegetables. The aim of the present study is to investigate the influence of I3C on radiosensitivity in epidermal growth factor receptor (EGFR)-positive and EGFR-negative lung cancer cell lines. Methods Human lung adenocarcinoma NIH-H1975 cells and human lung squamous carcinoma NIH-H226 and NIH-H520 cells were routinely cultured in RPMI-1640. MTT assay and clonogenic assay were used to detect cell growth and survival, respectively. Western blot and RT-PRC assay was employed to detect EGFR protein and mRNA expression. Results 5 μmol/L of I3C significantly reduced radiosensitivity of EGFR-positive NIH-H1975 and NIH-H226 cells, but failed to affect radiosensitivity of EGFR-negative NIH-H520 cells. Furthermore, I3C caused an increased expression of total EGFR and pEGFR (Y845) protein in NIH-H1975 and NIH-H226 cell lines, but not in NIH-H520 cell line. A reduction of EGFR expression by EGFR-siRNA significantly inhibited I3C-caused radioresistance in NIH-H1975 cells. Conclusion Our data presented here for the first time demonstrate that I3C reduces radiosensitivity of lung cancer cells by mediating EGFR expression, indicating that EGFR may be an important target for I3C-mediated radioresistance in lung cancer.
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- 2012
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6. BRCA1 regulates follistatin function in ovarian cancer and human ovarian surface epithelial cells.
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Tejaswita M Karve, Anju Preet, Rosie Sneed, Clara Salamanca, Xin Li, Jingwen Xu, Deepak Kumar, Eliot M Rosen, and Tapas Saha
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Medicine ,Science - Abstract
Follistatin (FST), a folliculogenesis regulating protein, is found in relatively high concentrations in female ovarian tissues. FST acts as an antagonist to Activin, which is often elevated in human ovarian carcinoma, and thus may serve as a potential target for therapeutic intervention against ovarian cancer. The breast cancer susceptibility gene 1 (BRCA1) is a known tumor suppressor gene in human breast cancer; however its role in ovarian cancer is not well understood. We performed microarray analysis on human ovarian carcinoma cell line SKOV3 that stably overexpress wild-type BRCA1 and compared with the corresponding empty vector-transfected clones. We found that stable expression of BRCA1 not only stimulates FST secretion but also simultaneously inhibits Activin expression. To determine the physiological importance of this phenomenon, we further investigated the effect of cellular BRCA1 on the FST secretion in immortalized ovarian surface epithelial (IOSE) cells derived from either normal human ovaries or ovaries of an ovarian cancer patient carrying a mutation in BRCA1 gene. Knock-down of BRCA1 in normal IOSE cells demonstrates down-regulation of FST secretion along with the simultaneous up-regulation of Activin expression. Furthermore, knock-down of FST in IOSE cell lines as well as SKOV3 cell line showed significantly reduced cell proliferation and decreased cell migration when compared with the respective controls. Thus, these findings suggest a novel function for BRCA1 as a regulator of FST expression and function in human ovarian cells.
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- 2012
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- View/download PDF
7. A new class of small molecule estrogen receptor-alpha antagonists that overcome anti-estrogen resistance
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Yongxian Ma, York Tomita, Eliseu O. De Oliveira, Robert Clarke, Yumi Ueda, Anju Preet, Li Zhang, Milton L. Brown, and Eliot M. Rosen
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medicine.drug_class ,Blotting, Western ,Mice, Nude ,Apoptosis ,Breast Neoplasms ,Electrophoretic Mobility Shift Assay ,Pharmacology ,Small Molecule Libraries ,estrogen receptor (ER-α) ,Benzophenones ,Mice ,Chalcones ,Piperidines ,medicine ,Tumor Cells, Cultured ,Animals ,Humans ,Immunoprecipitation ,Electrophoretic mobility shift assay ,skin and connective tissue diseases ,agonist ,Cell Proliferation ,Hormone response element ,Mice, Inbred BALB C ,business.industry ,Cell growth ,BRCA1 Protein ,Estrogen Antagonists ,Estrogen Receptor alpha ,antagonist ,Estrogens ,BRCA1 ,Molecular biology ,Xenograft Model Antitumor Assays ,Gene Expression Regulation, Neoplastic ,Tamoxifen ,Oncology ,Estrogen ,Drug Resistance, Neoplasm ,Female ,Signal transduction ,Pharmacophore ,business ,Estrogen receptor alpha ,medicine.drug ,Priority Research Paper ,Signal Transduction - Abstract
Previous studies indicate that BRCA1 protein binds to estrogen receptor-alpha (ER) and inhibits its activity. Here, we found that BRCA1 over-expression not only inhibits ER activity in anti-estrogen-resistant LCC9 cells but also partially restores their sensitivity to Tamoxifen. To simulate the mechanism of BRCA1 inhibition of ER in the setting of Tamoxifen resistance, we created a three-dimensional model of a BRCA1-binding cavity within the ER/Tamoxifen complex; and we screened a pharmacophore database to identify small molecules that could fit into this cavity. Among the top 40 "hits", six exhibited potent ER inhibitory activity in anti-estrogen-sensitive MCF-7 cells and four of the six exhibited similar activity (IC50 ≤ 1.0 μM) in LCC9 cells. We validated the model by mutation analysis. Two representative compounds (4631-P/1 and 35466-L/1) inhibited ER-dependent cell proliferation in Tamoxifen-resistant cells (LCC9 and LCC2) and partially restored sensitivity to Tamoxifen. The compounds also disrupted the association of BRCA1 with ER. In electrophoretic mobility shift assays, the compounds caused dissociation of ER from a model estrogen response element. Finally, a modified form of compound 35446 (hydrochloride salt) inhibited growth of LCC9 tumor xenografts at non-toxic concentrations. These results identify a novel group of small molecules that can overcome Tamoxifen resistance.
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- 2015
8. BRCA1-mimetic compound NSC35446.HCl inhibits IKKB expression by reducing estrogen receptor-α occupancy in the IKKB promoter and inhibits NF-κB activity in antiestrogen-resistant human breast cancer cells
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Eliot M. Rosen, Shyam Nathan, Milton L. Brown, Eliseu O. De Oliveira, York A. Tomita, and Yongxian Ma
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0301 basic medicine ,Cancer Research ,Estrogen receptor ,Apoptosis ,Breast Neoplasms ,Biology ,Pharmacology ,Article ,03 medical and health sciences ,0302 clinical medicine ,Humans ,skin and connective tissue diseases ,Promoter Regions, Genetic ,Estrogen receptor beta ,Cell Proliferation ,Hormone response element ,Cell growth ,Activator (genetics) ,BRCA1 Protein ,Estrogen Antagonists ,Estrogen Receptor alpha ,NF-kappa B ,Estrogens ,Antiestrogen ,I-kappa B Kinase ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,Oncology ,Cell culture ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Cancer cell ,Cancer research ,MCF-7 Cells ,hormones, hormone substitutes, and hormone antagonists - Abstract
We previously identified small molecules that fit into a BRCA1-binding pocket within estrogen receptor-alpha (ERα), mimic the ability of BRCA1 to inhibit ERα activity (“BRCA1-mimetics”), and overcome antiestrogen resistance. One such compound, the hydrochloride salt of NSC35446 (“NSC35446.HCl”), also inhibited the growth of antiestrogen-resistant LCC9 tumor xenografts. The purpose of this study was to investigate the down-stream effects of NSC35446.HCl and its mechanism of action. Here, we studied antiestrogen-resistant (LCC9, T47DCO, MCF-7/RR, LY2), ERα-negative (MDA-MB-231, HCC1806, MDA-MB-468), and antiestrogen-sensitive (MCF-7) cell lines. Techniques utilized include RNA-seq, qRT-PCR, cell growth analysis, cell-cycle analysis, Western blotting, luciferase reporter assays, TUNEL assays, in silico analysis of the IKKB gene, and ChIP assays. SC35446.HCl inhibited proliferation and induced apoptosis in antiestrogen-resistant LCC9, T47DCO, MCF-7/RR, and LY2 cells but not in ERα-negative breast cancer cell lines. IKKB (IKKβ, IKBKB), an upstream activator of NF-κB, was identified as a BRCA1-mimetic-regulated gene based on an RNA-seq analysis. NSC35446.HCl inhibited IKKB, IKKA, and IKKG/NEMO mRNA and protein expression in LCC9 cells. NSC35446.HCl also inhibited NF-κB activity and expression of NF-κB target genes. In silico analysis of the IKKB promoter identified nine estrogen response element (ERE) half-sites and one ERE-like full-site. ChIP assays revealed that ERα was recruited to the ERE-like full-site and five of the nine half-sites and that ERα recruitment was inhibited by NSC35446.HCl in LCC9 and T47DCO cells. These studies identify functional EREs in the IKKB promoter and identify IKKB as an ERα and NSC35446.HCl-regulated gene, and they suggest that NF-κB and IKKB, which were previously linked to antiestrogen resistance, are targets for NSC35446.HCl in reversing antiestrogen resistance.
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- 2017
9. BRCA1 and 2
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Eliot M. Rosen
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- 2017
10. Targeting the BRCA1/2 Tumor Suppressors
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Michael J. Pishvaian and Eliot M. Rosen
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Base Pair Mismatch ,DNA repair ,Genes, BRCA2 ,Clinical Biochemistry ,Genes, BRCA1 ,Synthetic lethality ,Biology ,Gene mutation ,medicine.disease_cause ,DNA Mismatch Repair ,Olaparib ,chemistry.chemical_compound ,PARP1 ,Drug Discovery ,medicine ,Humans ,Genes, Tumor Suppressor ,skin and connective tissue diseases ,Pharmacology ,Genetics ,Mutation ,chemistry ,Gene Targeting ,PARP inhibitor ,Molecular Medicine ,DNA mismatch repair - Abstract
The breast cancer susceptibility genes BRCA1 and BRCA2 are classic tumor suppressor genes that exhibit an autosomal dominant pattern of inheritance with high penetrance. BRCA carriers inherit one mutant BRCA allele and one wild-type allele; and the wild-type allele is invariably deleted or mutated within the tumor. These genes function as caretakers in the maintenance of genomic stability, in part, by participating in homology-directed DNA repair (HDR), an error- free mechanism for the repair of double-strand breaks (DSBs). PARP1 (poly (ADP-ribose) polymerase 1) is an enzyme that functions in the base excision repair (BER) pathway, where its ability to post-translationally modify histones and DNA damage response proteins is required for repair of single-strand breaks (SSBs). In 2005, it was observed that knockdown of PARP1 or treatment with a small molecule PARP inhibitor was far more toxic to cells with BRCA1 or BRCA2 mutations than BRCA1/2-competent cells. This observation is an example of "synthetic lethality", a concept whereby two gene mutations combine to cause cell death, when neither mutation alone is lethal. These results spawned the idea to use PARP inhibitors to treat BRCA1/2 mutant cancers. Here, we will review the basic science underlying the discoveries described above, the preclinical research, and the clinical trials designed to exploit the sensitivity of BRCA1/2 mutant tumor cells to PARP inhibitors. We will also describe problems associated with the use of these agents, including development and mechanisms of drug resistance; and we will provide a forward look at new agents and strategies currently under development.
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- 2014
11. Sanguinarine is a novel VEGF inhibitor involved in the suppression of angiogenesis and cell migration
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Yu Chong, Yang Jiao, Jiaying Xu, Qinghui Meng, Saijun Fan, Lin Zhao, and Eliot M. Rosen
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Tube formation ,Cancer Research ,Oncogene ,Angiogenesis ,Cancer ,Cell migration ,Articles ,Biology ,medicine.disease ,Vascular endothelial growth factor ,chemistry.chemical_compound ,Oncology ,chemistry ,Cancer research ,medicine ,Sanguinarine ,Protein kinase B - Abstract
Vascular endothelial growth factor (VEGF) is a main angiogenic factor which is known to be upregulated in lung cancer. In the present study, it was demonstrated that sanguinarine, an alkaloid obtained from the bloodroot plant, markedly repressed the VEGF-induced tube formation of human microvascular endothelial cells (HMVECs) and the migration of human A549 lung cancer cells. Furthermore, sanguinarine decreased VEGF secretion and expression in HMVECs and A549 lung cancer cells in a dose- and time-dependent manner. Additionally, sanguinarine inhibited the activation of serum starvation- and hypoxia-induced VEGF promoter activity. Sanguinarine also inhibited the VEGF-mediated Akt and p38 activation, as well as VE-cadherin protein phosphorylation. To the best of our knowledge, this is the first study demonstrating that VEGF inhibition appears to be an important mechanism involved in the antiangiogenic and anti-invasive activities of sanguinarine in lung cancer treatment.
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- 2012
12. Sanguinarine inhibits growth of human cervical cancer cells through the induction of apoptosis
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Jiaying Xu, Qinghui Meng, Lin Zhao, Saijun Fan, Eliot M. Rosen, Yu Chong, and Yang Jiao
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Cancer Research ,Cell Survival ,Cell ,Population ,Uterine Cervical Neoplasms ,Apoptosis ,HeLa ,chemistry.chemical_compound ,Anti-Infective Agents ,Cell Line, Tumor ,medicine ,Humans ,Sanguinarine ,education ,Cell Proliferation ,Benzophenanthridines ,education.field_of_study ,biology ,Oncogene ,Cell Cycle ,NF-kappa B ,Cell Cycle Checkpoints ,General Medicine ,Cell cycle ,Isoquinolines ,biology.organism_classification ,female genital diseases and pregnancy complications ,medicine.anatomical_structure ,Proto-Oncogene Proteins c-bcl-2 ,Oncology ,chemistry ,Cell culture ,Cancer research ,Female ,Cell Division ,HeLa Cells - Abstract
Sanguinarine, a natural benzophenanthridine alkaloid, has been shown to possess anticancer activity in vitro and in vivo. In the present study, we demonstrated that sanguinarine caused a dose-dependent inhibition of growth in HeLa and SiHa human cervical cancer cells, i.e., 2.43 µmol/l (IC50) in HeLa cells and 3.07 µmol/l in SiHa cells. Cell cycle analysis revealed that sanguinarine significantly increased the sub-G1 population, from 1.7 to 59.7% in HeLa cells and from 1.7 to 41.7% in SiHa cells. Sanguinarine caused a dose-dependent decrease in Bcl-2 and NF-κB protein expression and a significant increase in Bax protein expression. Our findings indicate that sanguinarine as an effective anticancer drug candidate inhibits the growth of cervical cancer cells through the induction of apoptosis.
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- 2012
13. High-Mobility Group Boxes Mediate Cell Proliferation and Radiosensitivity via Retinoblastoma-Interaction-Dependent and -Independent Mechanisms
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Haichao Wang, Eliot M. Rosen, Ju-Ying Zhou, Chun-Min Ge, Yang Jiao, Qinghui Meng, Saijun Fan, Jiaying Xu, and Lili Wang
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Cancer Research ,Molecular Sequence Data ,Breast Neoplasms ,chemical and pharmacologic phenomena ,Cell Growth Processes ,Plasma protein binding ,Biology ,Transfection ,Radiation Tolerance ,Retinoblastoma Protein ,Cell Line, Tumor ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Amino Acid Sequence ,Binding site ,Peptide sequence ,Pharmacology ,Binding Sites ,Retinoblastoma ,Cell growth ,Point mutation ,High Mobility Group Proteins ,Original Articles ,General Medicine ,medicine.disease ,Molecular biology ,Blot ,High-mobility group ,Oncology ,Female ,Protein Binding - Abstract
Our previous studies have shown that high-mobility group box 1 (HMGB1) could physically associate with the retinoblastoma (RB) protein via an LXCXE (leucine-X-cysteine-X-glutamic; X=any amino acid) motif. An identical LXCXE motif is present in the HMGB1–3 protein sequences, whereas a near-consensus LXCXD (leucine-X-cysteine-X-asparagine; X=any amino acid) motif is found in the HMGB4 protein. In this study, we have demonstrated that like HMGB1, HMGB2–3 also associated with the RB in vitro and in vivo, as evidenced by glutathione-s-transferase capture and immunoprecipitation–Western blot assays. A point mutation of the LXCXE or LXCXD motif led to disruption of RB:HMGB1–4 interactions. Enforced expression of HMGB1–3 or HMGB4 by adenoviral-vector-mediated gene transfer resulted in significant inhibition of breast cancer cell proliferation through an LXCXE- or LXCXD-dependent mechanism and an increased radiosensitivity through an LXCXE- or LXCXD-independent mechanism. These results suggest an important role of the LXCXE/D motif in RB:HMGB1–4 association and modulation of cancer cell growth, but not radiosensitivity.
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- 2012
14. BTG2 is an LXXLL-dependent co-repressor for androgen receptor transcriptional activity
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Xu-Dong Hu, Saijun Fan, Ping Wang, Jiaying Xu, Eliot M. Rosen, Qinghui Meng, Chun-Min Ge, Asha Jacob, and Yang Jiao
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Male ,Transcription, Genetic ,Tumor suppressor gene ,Biophysics ,Biology ,Biochemistry ,Immediate-Early Proteins ,Prostate cancer ,Cell Line, Tumor ,medicine ,Humans ,Molecular Biology ,Cell Proliferation ,Regulation of gene expression ,Leucine Zippers ,BTG2 ,Tumor Suppressor Proteins ,5-alpha-Dihydroprogesterone ,Prostatic Neoplasms ,Cell Biology ,medicine.disease ,Gene Expression Regulation, Neoplastic ,Repressor Proteins ,Androgen receptor ,Nuclear receptor ,Receptors, Androgen ,Mutation ,Cancer research ,Ectopic expression ,Signal transduction - Abstract
The tumor suppressor gene, BTG2 has been down-regulated in prostate cancer and the ectopic expression of this gene has been shown to inhibit prostate cancer cell growth. Sequence analysis revealed that the BTG2 protein contains two leucine-rich motifs ((20)LxxLL(24) and (92)LxxLL(96)), which are usually found in nuclear receptor co-factors. Based on this, we postulated that there will be an association between BTG2 and AR. In this study, we discovered that BTG2 directly bound to the androgen receptor (AR) in the absence of 5α-dihydrotestosterone (DHT), and in the presence of the androgen, this interaction was increased. BTG2 bearing the mutant (20)LxxLL(24) motif bound to AR equally efficient as the wild-type BTG2, while BTG2 bearing the mutant (92)LxxLL(96) motif failed to interact with AR. Functional studies indicated that ectopic expression of BTG2 caused a significant inhibition of AR-mediated transcriptional activity and a decreased growth of prostate cancer cells. Androgen-induced promoter activation and expression of prostate-specific antigen (PSA) are significantly attenuated by BTG2. The intact (92)LxxLL(96) motif is required for these activities. These findings, for the first time, demonstrate that BTG2 complexes with AR via an LxxLL-dependent mechanism and may play a role in prostate cancer via modulating the AR signaling pathway.
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- 2011
15. UHRF1 confers radioresistance to human breast cancer cells
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Qinghui Meng, Saijun Fan, Eliot M. Rosen, and Xin-li Li
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Ubiquitin-Protein Ligases ,Apoptosis ,Breast Neoplasms ,DNA Fragmentation ,Biology ,Radiation Tolerance ,Mice ,Cell Line, Tumor ,Radioresistance ,Animals ,Humans ,Radiology, Nuclear Medicine and imaging ,Radiosensitivity ,Annexin A5 ,Ku Autoantigen ,bcl-2-Associated X Protein ,Radiological and Ultrasound Technology ,Nuclear Proteins ,Antigens, Nuclear ,Transfection ,Cell cycle ,Flow Cytometry ,Molecular biology ,DNA-Binding Proteins ,Drug Resistance, Neoplasm ,Cancer cell ,CCAAT-Enhancer-Binding Proteins ,Cancer research ,DNA fragmentation - Abstract
To investigate the effect of ubiquitin-like with plant homeodomain (PHD) and ring finger domains 1 (UHRF1) overexpression on radiosensitivity to X-rays in human breast cancer MDA-MB-231 cells.Cell survival was determined by colony formation assay; cell cycle distribution was measured by flow cytometry; apoptosis was evaluated by DNA fragmentation assay and Annexin V apoptosis detection kit; protein expression was analysed by Western blot assay; chromosome aberrations (centric rings and dicentrics) were assayed by conventional chromosome analysis.A significant decrease of radiosensitivity to X-rays was observed in MDA-MB-231 cells transfected with a full-length of human UHRF1 cDNA (MDA-MB-231/UHRF1) compared to the control cells (MDA-MB-231/parental and MDA-MB-231/pcDNA3 [mammalian expression vector]), and the similar results were observed in MDA-MB-468 cells. In contrast, a decreased expression of UHRF1 by a specific UHRF1-small interfering RNA (siRNA) significantly enhanced cell radiosensitivity. The UHRF1-mediated radioresistance was correlated with a G2(Ra)/M arrest, a decreased induction of apoptosis, a down-regulation of the pro-apoptotic protein anti-B cell lymphoma/leukemia 2 (bcl-2) associated X protein (Bax) and a up-regulation of the DNA damage repair proteins Lupus Ku autoantigen protein p70 (Ku-70) and Lupus Ku autoantigen protein p80 (Ku-80). Furthermore, chromosomal aberrations (centric rings and dicentrics) by X-rays were less in MDA-MB-231/UHRF1 than in MDA-MB-231/parental and MDA-MB-231/pcDNA3 control cells.These results suggested that UHRF1 may be a new target in the radiotherapy of breast cancer via affecting apoptosis and DNA damage repair.
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- 2010
16. BRCA1 Regulates Acetylation and Ubiquitination of Estrogen Receptor-α
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Yongxian Ma, Saijun Fan, Changyan Hu, Richard G. Pestell, York Tomita, Eliot M. Rosen, Suzanne A. W. Fuqua, and Qinghui Meng
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Male ,endocrine system diseases ,Mutant ,Lysine ,Genes, BRCA1 ,Estrogen receptor ,Breast Neoplasms ,P300-CBP Transcription Factors ,Biology ,Transfection ,Article ,Endocrinology ,Ubiquitin ,Genes, Reporter ,Cell Line, Tumor ,Coactivator ,Humans ,p300-CBP Transcription Factors ,RNA, Small Interfering ,skin and connective tissue diseases ,Molecular Biology ,Phosphoinositide-3 Kinase Inhibitors ,Estradiol ,BRCA1 Protein ,Estrogen Receptor alpha ,Ubiquitination ,Prostatic Neoplasms ,Acetylation ,General Medicine ,Molecular biology ,Gene Knockdown Techniques ,Mutation ,biology.protein ,Female ,Protein Processing, Post-Translational ,Proto-Oncogene Proteins c-akt ,Estrogen receptor alpha ,Protein Binding - Abstract
Inherited mutations of the breast cancer susceptibility gene BRCA1 confer a high risk for breast cancer development. The (300)RXKK and (266)KXK motifs have been identified previously as sites for acetylation of the estrogen receptor-alpha (ER-alpha), and (302)K was also found to be a site for BRCA1-mediated mono-ubiquitination of ER-alpha in vitro. Here we show that ER-alpha proteins with single or double lysine mutations of these motifs (including K303R, a cancer-associated mutant) are resistant to inhibition by BRCA1, even though the mutant ER-alpha proteins retain the ability to bind to BRCA1. We also found that BRCA1 overexpression reduced and knockdown increased the level of acetylated wild-type ER-alpha, without changing the total ER-alpha protein level. Increased acetylation of ER-alpha due to BRCA1 small interfering RNA was dependent upon phosphatidylinositol 3-kinase/Akt signaling and on up-regulation of the coactivator p300. In addition, using an in vitro acetylation assay, we found that in vitro-translated wild-type BRCA1 but not a cancer-associated point mutant (C61G) inhibited p300-mediated acetylation of ER-alpha. Furthermore, BRCA1 overexpression increased the levels of mono-ubiquitinated ER-alpha protein, and a BRCA1 mutant that is defective for ubiquitin ligase activity but retains other BRCA1 functions (I26A) did not ubiquitinate ER-alpha or repress its activity in vivo. Finally, ER-alpha proteins with mutations of the (300)RXKK or (266)KXK motifs showed modest or no BRCA1-induced ubiquitination. We propose a model in which BRCA1 represses ER-alpha activity, in part, by regulating the relative degree of acetylation vs. ubiquitination of ER-alpha.
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- 2010
17. Scatter factor protects tumor cells against apoptosis caused by TRAIL
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Qinghui Meng, John Laterra, Eliot M. Rosen, and Saijun Fan
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Cancer Research ,Programmed cell death ,Indoles ,C-Met ,Transcription, Genetic ,Cell Survival ,Blotting, Western ,Cell ,Apoptosis ,Biology ,Inhibitor of apoptosis ,TNF-Related Apoptosis-Inducing Ligand ,chemistry.chemical_compound ,Dogs ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Immunoprecipitation ,Pharmacology (medical) ,Sulfones ,RNA, Small Interfering ,Receptor ,Pharmacology ,Cyclooxygenase 2 Inhibitors ,Hepatocyte Growth Factor ,NF-kappa B ,Epithelial Cells ,Proto-Oncogene Proteins c-met ,Flow Cytometry ,Molecular biology ,Recombinant Proteins ,medicine.anatomical_structure ,Oncology ,chemistry ,Cyclooxygenase 2 ,Drug Resistance, Neoplasm ,Tumor necrosis factor alpha ,Hepatocyte growth factor ,medicine.drug - Abstract
Scatter factor (SF) and its receptor c-Met are overexpressed in various tumor types, and their expression often correlates with a poor prognosis. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), is a proposed tumor-specific chemotherapy agent, but its clinical usage is limited by acquisition of TRAIL resistance by tumors. The goals of this study were to determine whether and how SF protects tumor cells against TRAIL and whether SF-induced TRAIL resistance could be reversed. We used MTT assays, trypan blue dye exclusion assays, apoptosis assays, RNA interference, luciferase reporter assays, immunoprecipitation/western blotting, and other cell biological techniques to study SF protection of cultured human tumor cells against TRAIL. SF conferred resistance to TRAIL in various human prostate carcinoma and breast carcinoma cell lines. SF inhibited TRAIL-induced caspase-3 activation, poly (ADP-ribose) polymerase cleavage, and cell death. SF protection against TRAIL required c-Akt; but unlike protection against adriamycin, it did not require Src signaling or the classical pathway of nuclear factor-kappaB activation. Protection against TRAIL was blocked by knockdown of X-linked inhibitor of apoptosis or FLICE-inhibitor protein (FLIP) (a component of the death-inducing signaling complex). We found that c-Met physically associates with several TRAIL receptors and SF regulates their protein stability. Protection against TRAIL was blocked by a novel small molecule inhibitor of c-Met (PHA665752) and by an inhibitor of cyclooxygenase 2. In conclusion, these findings elucidate potential mechanisms of TRAIL resistance in tumors that overexpress the SF/c-Met and identify possible means of reversing this resistance.
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- 2010
18. Role of Src Signal Transduction Pathways in Scatter Factor-mediated Cellular Protection
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John Laterra, Qinghui Meng, Saijun Fan, and Eliot M. Rosen
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Male ,rac1 GTP-Binding Protein ,MAP Kinase Signaling System ,MAP Kinase Kinase 3 ,Proto-Oncogene Proteins pp60(c-src) ,MAP Kinase Kinase 6 ,IκB kinase ,Biology ,p38 Mitogen-Activated Protein Kinases ,Biochemistry ,src Homology Domains ,Dogs ,Cell Line, Tumor ,Neoplasms ,Animals ,Humans ,Molecular Biology ,Protein kinase B ,Antibiotics, Antineoplastic ,MAP kinase kinase kinase ,Hepatocyte Growth Factor ,Kinase ,Mechanisms of Signal Transduction ,NF-kappa B ,I-Kappa-B Kinase ,Cell Biology ,Proto-Oncogene Proteins c-met ,MAP Kinase Kinase Kinases ,I-kappa B Kinase ,Cell biology ,Doxorubicin ,Drug Resistance, Neoplasm ,Cancer research ,Signal transduction ,Proto-Oncogene Proteins c-akt ,Proto-oncogene tyrosine-protein kinase Src - Abstract
Scatter factor (SF) (hepatocyte growth factor) is a pleiotrophic cytokine that accumulates in tumors, where it may induce invasion, angiogenesis, and chemoresistance. We have studied the mechanisms by which SF and its receptor (c-Met) protect cells against the DNA-damaging agent adriamycin (ADR) as a model for chemoresistance of SF/c-Met-overexpressing tumors. Previous studies identified a phosphatidylinositol 3-kinase/c-Akt/Pak1/NF-kappaB cell survival pathway in DU-145 prostate cancer and Madin-Darby canine kidney epithelial cells. Here we studied Src signaling pathways involved in SF cell protection. Src enhanced basal and SF stimulated NF-kappaB activity and SF protection against ADR, in a manner dependent upon its kinase and Src homology 3 domains; and endogenous Src was required for SF stimulation of NF-kappaB activity and cell protection. The ability of Src to enhance SF stimulation of NF-kappaB activity was due, in part, to its ability to stimulate Akt and IkappaB kinase activity; and Src-mediated stimulation of NF-kappaB was due, in part, to a Rac1/MKK3/6/p38 pathway and was Akt-dependent. SF caused the activation of Src and the Rac1 effector Pak1. Furthermore, SF induced activating phosphorylations of MKK3, MKK6, and p38 within the c-Met signalsome in an Src-dependent manner. The NF-kappaB-inducing kinase was found to act downstream of TAK1 (transforming growth factor-beta-activated kinase 1) as a mediator of SF- and Src-stimulated NF-kappaB activity. Finally, the Src/Rac1/MKK3/6/p38 and Src/TAK1/NF-kappaB-inducing kinase pathways exhibited cross-talk at the level of MKK3. These findings delineate some novel signaling pathways for SF-mediated resistance to ADR.
- Published
- 2009
19. Microbeam radiation therapy: Tissue dose penetration and BANG-gel dosimetry of thick-beams’ array interlacing
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Mark E. Wagshul, Marek J. Maryanski, Pantaleo Romanelli, F. Avraham Dilmanian, Ruiliang Wang, John Kalef-Ezra, Zhong Zhong, David J. Anschel, and Eliot M. Rosen
- Subjects
Monte Carlo method ,Gel dosimetry ,Models, Biological ,Radiotherapy, High-Energy ,Optics ,Planar ,Humans ,Scattering, Radiation ,Dosimetry ,Medicine ,Computer Simulation ,Radiology, Nuclear Medicine and imaging ,Irradiation ,Radiometry ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Brain ,Radiotherapy Dosage ,General Medicine ,Microbeam ,Mockup ,business ,Nuclear medicine ,Gels ,Monte Carlo Method ,Algorithms ,Synchrotrons ,Beam (structure) - Abstract
The tissue-sparing effect of parallel, thin (narrower than 100 μm) synchrotron-generated X-ray planar beams (microbeams) in healthy tissues including the central nervous system (CNS) is known since early 1990s. This, together with a remarkable preferential tumoricidal effect of such beam arrays observed at high doses, has been the basis for labeling the method microbeam radiation therapy (MRT). Recent studies showed that beams as thick as 0.68 mm (“thick microbeams”) retain part of their sparing effect in the rat's CNS, and that two such orthogonal microbeams arrays can be interlaced to produce an unsegmented field at the target, thus producing focal targeting. We measured the half-value layer (HVL) of our 120-keV median-energy beam in water phantoms, and we irradiated stereotactically bis acrylamide nitrogen gelatin (BANG)-gel-filled phantoms, including one containing a human skull, with interlaced microbeams and imaged them with MRI. A 43-mm water HVL resulted, together with an adequately large peak-to-valley ratio of the microbeams’ three-dimensional dose distribution in the vicinity of the 20 mm × 20 mm × 20 mm target deep into the skull. Furthermore, the 80–20% dose falloff was a fraction of a millimeter as predicted by Monte Carlo simulations. We conclude that clinical MRT will benefit from the use of higher beam energies than those used here, although the current energy could serve certain neurosurgical applications. Furthermore, thick microbeams particularly when interlaced present some advantages over thin microbeams in that they allow the use of higher beam energies and they could conceivably be implemented with high power orthovoltage X-ray tubes.
- Published
- 2008
20. Transcription-Dependent Epidermal Growth Factor Receptor Activation by Hepatocyte Growth Factor
- Author
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Shuli Xia, Thomas E. Reznik, Yongxian Ma, Roger Abounader, John Laterra, Yingying Sang, and Eliot M. Rosen
- Subjects
Cancer Research ,TGF alpha ,Transcription, Genetic ,Heparin-binding EGF-like growth factor ,medicine.medical_treatment ,Ligands ,Article ,Receptor tyrosine kinase ,Bacterial Proteins ,Growth factor receptor ,Cell Line, Tumor ,medicine ,Humans ,Growth factor receptor inhibitor ,RNA, Messenger ,Epidermal growth factor receptor ,Phosphorylation ,RNA, Small Interfering ,Phosphotyrosine ,Molecular Biology ,Cell Proliferation ,biology ,Hepatocyte Growth Factor ,Growth factor ,Transforming Growth Factor alpha ,Cell biology ,Enzyme Activation ,ErbB Receptors ,Gene Expression Regulation, Neoplastic ,Oncology ,Cytoprotection ,Protein Biosynthesis ,biology.protein ,Cancer research ,Intercellular Signaling Peptides and Proteins ,Hepatocyte growth factor ,Mitogen-Activated Protein Kinases ,DNA Damage ,Heparin-binding EGF-like Growth Factor ,medicine.drug - Abstract
The mechanisms and biological implications of coordinated receptor tyrosine kinase coactivation remain poorly appreciated. Epidermal growth factor receptor (EGFR) and c-Met are frequently coexpressed in cancers, including those associated with hepatocyte growth factor (HGF) overexpression, such as malignant astrocytoma. In a previous analysis of the HGF-induced transcriptome, we found that two EGFR agonists, transforming growth factor-α and heparin-binding epidermal growth factor–like growth factor (HB-EGF), are prominently up-regulated by HGF in human glioma cells. We now report that stimulating human glioblastoma cells with recombinant HGF induces biologically relevant EGFR activation. EGFR phosphorylation at Tyr845 and Tyr1068 increased 6 to 24 h after cell stimulation with HGF and temporally coincided with the induction of transforming growth factor-α (∼5-fold) and HB-EGF (∼23-fold) expression. Tyr845 and Tyr1068 phosphorylation, in response to HGF, was inhibited by cycloheximide and actinomycin D, consistent with a requirement for DNA transcription and RNA translation. Specifically, blocking HB-EGF binding to EGFR with the antagonist CRM197 inhibited HGF-induced EGFR phosphorylation by 60% to 80% and inhibited HGF-induced S-G2-M transition. CRM197 also inhibited HGF-induced anchorage-dependent cell proliferation but had no effect on HGF-mediated cytoprotection. These findings establish that EGFR can be activated with functional consequences by HGF as a result of EGFR ligand expression. This transcription-dependent cross-talk between the HGF receptor c-Met and EGFR expands our understanding of receptor tyrosine kinase signaling networks and may have considerable consequences for oncogenic mechanisms and cancer therapeutics. (Mol Cancer Res 2008;6(1):139–50)
- Published
- 2008
21. Growth Factor Signaling Pathways Modulate BRCA1 Repression of Estrogen Receptor-α Activity
- Author
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Changyan Hu, Yongxian Ma, Anna T. Riegel, Saijun Fan, and Eliot M. Rosen
- Subjects
Male ,BRCA1 Protein ,Estrogen Receptor alpha ,General Medicine ,Protein phosphatase 2 ,Biology ,Serine ,Phosphatidylinositol 3-Kinases ,Endocrinology ,Cell Line, Tumor ,Cancer research ,Humans ,Intercellular Signaling Peptides and Proteins ,Phosphorylation ,Female ,Signal transduction ,skin and connective tissue diseases ,Proto-Oncogene Proteins c-akt ,Molecular Biology ,Protein kinase B ,Estrogen receptor alpha ,Estrogen receptor beta ,PI3K/AKT/mTOR pathway ,Signal Transduction - Abstract
The breast cancer susceptibility gene BRCA1 is mutated in about one half of all hereditary breast cancer cases, and its expression is frequently decreased in sporadic cancers. Previously, we demonstrated a functional interaction between the BRCA1 and estrogen receptor-alpha (ER-alpha) proteins that causes inhibition of ER-alpha signaling. Here, we examined the role of growth factor signaling pathways in modulating this interaction. We found that underexpression of BRCA1 caused ligand-independent activation of ER-alpha that was mediated through phosphatidylinositol-3 kinase (PI3K)/c-Akt signaling. BRCA1 underexpression also enhanced estrogen-inducible ER-alpha activity in a PI3K/Akt-dependent manner. Exogenous c-Akt conferred estrogen-independent ER-alpha activation and rescued the BRCA1 repression of estrogen-stimulated ER-alpha activity. BRCA1 knockdown stimulated c-Akt activity, in part, by inhibiting the activity of protein phosphatase 2A, an enzyme that dephosphorylates Akt. ERs with point mutations of several growth factor-targeted serine residues (S167A, S118A, and S118/167A) were resistant to repression by BRCA1, although the single point mutant receptors still associated with the BRCA1 protein. The enhanced ER-alpha activity attributable to BRCA1 knockdown was dependent, in part, on serine residues 167 and 118 of ER-alpha. BRCA1 knockdown caused an increase in ER-alpha phosphorylation on serine-167 (but not serine-118 or serine-104/106) that was dependent on PI3K/Akt signaling and was mimicked by pharmacologic inhibition of protein phosphatase 2A. These findings suggest that BRCA1 regulates Akt signaling and the PI3K/Akt pathway modulates the ability of BRCA1 to repress ER-alpha, in part through serine phosphorylation events in the activation function-1 domain of ER-alpha.
- Published
- 2007
22. Ras effector pathways modulate scatter factor-stimulated NF-κB signaling and protection against DNA damage
- Author
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John Laterra, Eliot M. Rosen, Qinghui Meng, and Saijun Fan
- Subjects
Cancer Research ,Cell Survival ,Genetic Vectors ,IκB kinase ,Biology ,Transfection ,Cell Line ,PAK1 ,Cell Line, Tumor ,Anti-apoptotic Ras signalling cascade ,Genetics ,medicine ,Animals ,Humans ,Phosphorylation ,Kinase activity ,Molecular Biology ,Cell Proliferation ,Antibiotics, Antineoplastic ,Dose-Response Relationship, Drug ,Hepatocyte Growth Factor ,Effector ,Kinase ,NF-kappa B ,RALA ,I-kappa B Kinase ,Proto-Oncogene Proteins c-raf ,Doxorubicin ,Mutation ,ras Proteins ,Cancer research ,RNA Interference ,ral GTP-Binding Proteins ,Hepatocyte growth factor ,Mitogen-Activated Protein Kinases ,DNA Damage ,Protein Binding ,Signal Transduction ,medicine.drug - Abstract
Scatter factor (SF) (hepatocyte growth factor) is a pleiotrophic cytokine that accumulates within tumors in vivo and protects tumor cells against cytotoxicity and apoptosis due to DNA damaging agents in vitro. Previous studies have established that SF-mediated cell protection involves antiapoptotic signaling from its receptor (c-Met) to PI3 kinase --> c-Akt --> Pak1 (p21-activated kinase -1) --> NF-kappaB (nuclear factor-kappa B). Here, we found that Ras proteins (H-Ras and R-Ras) enhance SF-mediated activation of NF-kappaB and protection of DU-145 and MDCK (Madin-Darby canine kidney) cells against the topoisomerase IIalpha inhibitor adriamycin. Studies of Ras effector loop mutants and their downstream effectors suggest that Ras/PI3 kinase and Ras/Raf1 pathways contribute to SF stimulation of NF-kappaB signaling and cell protection. Further studies revealed that Raf1 positively regulates the ability of SF to stimulate NF-kappaB activity and cell protection. The ability of Raf1 to stimulate NF-kappaB activity was not due to the classical Raf1 --> MEK1/2 --> ERK1/2 pathway. However, we found that a MEK3/6 --> p38 pathway contributes to SF-mediated activation of NF-kappaB. In contrast, RalA, a target of the Ras/RalGDS pathway negatively regulated the ability of SF to stimulate NF-kappaB activity and cell protection. Ras, Raf1 and RalA modulate SF stimulation of NF-kappaB activity, in part, by regulating IkappaB kinase (IKK)-beta kinase activity. These findings suggest that Ras/Raf1/RalA pathways may converge to modulate NF-kappaB activation and SF-mediated survival signaling at the IKK complex and/or a kinase upstream of this complex.
- Published
- 2007
23. New Approaches to Radiation Protection
- Author
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Regina M. Day, Vijay K. Singh, and Eliot M. Rosen
- Subjects
medicine.medical_specialty ,Pathology ,Cancer Research ,medicine.medical_treatment ,Normal tissue ,Review Article ,Dirty bomb ,lcsh:RC254-282 ,cancer treatment ,medicine ,Irradiation ,Intensive care medicine ,Radiation injury ,irradiation ,business.industry ,radioprotectors ,Advanced stage ,mitigators ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,3. Good health ,Cancer treatment ,Radiation therapy ,Oncology ,Radiation protection ,business ,radiation protection - Abstract
Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or deliberate exposure (e.g., nuclear reactor meltdown, dirty bomb, or nuclear bomb explosion); hence they are called radiation countermeasures. Here, we will review the general principles of radiation injury and protection and describe selected examples of radioprotectors/mitigators ranging from small-molecules to proteins to cell-based treatments. We will emphasize agents that are in more advanced stages of development.
- Published
- 2015
- Full Text
- View/download PDF
24. BRCA1 and 2
- Author
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Eliot M. Rosen
- Subjects
Biology - Published
- 2015
25. Effect of Akt inhibition on scatter factor-regulated gene expression in DU-145 human prostate cancer cells
- Author
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John Laterra, Saijun Fan, Itzhak D. Goldberg, J Xu, Min Gao, Eliot M. Rosen, Habtom W. Ressom, Qinghui Meng, and Roger Abounader
- Subjects
Male ,Cancer Research ,medicine.medical_specialty ,Cell ,Protein Serine-Threonine Kinases ,Biology ,medicine.disease_cause ,Internal medicine ,Gene expression ,Tumor Cells, Cultured ,Genetics ,medicine ,Humans ,RNA, Small Interfering ,Molecular Biology ,Oligonucleotide Array Sequence Analysis ,Gene knockdown ,Hepatocyte Growth Factor ,Gene Expression Profiling ,NF-kappa B ,Prostatic Neoplasms ,Transfection ,Gene Expression Regulation, Neoplastic ,Oncogene Protein v-akt ,Gene expression profiling ,Endocrinology ,medicine.anatomical_structure ,p21-Activated Kinases ,Doxorubicin ,Drug Resistance, Neoplasm ,Cancer cell ,Cancer research ,Hepatocyte growth factor ,Carcinogenesis ,medicine.drug - Abstract
The cytokine scatter factor (SF) (hepatocyte growth factor) transduces various biologic actions, including cell motility, invasion, angiogenesis and apoptosis inhibition. The latter is relevant to understanding the role of SF in promoting tumor cell survival in different contexts, for example, detachment from basement membrane, growth in metastatic sites and responses to chemo- and radiotherapy. Previously, we showed that SF protects cells against apoptosis owing to DNA damage, by a mechanism involving phosphoinositol-3-kinase/c-Akt signaling. Here, we used DNA microarray assays to identify c-Akt-regulated genes that might contribute to cell protection. DU-145 human prostate cancer cells were transfected+/-a dominant-negative mutant Akt, treated+/-SF and analysed for gene expression using Affymetrix arrays. These studies identified SF-regulated genes for which induction was c-Akt-dependent vs -independent. Selected microarray findings were confirmed by semiquantitative and quantitative reverse transcription-polymerase chain reaction. We tested the contribution of four SF-inducible/c-Akt-dependent genes (AMPD3, EPHB2, MX1 and WNT4) to protection against adriamycin (a DNA topoisomerase IIalpha inhibitor) using RNA interference. Knockdown of each gene except EPHB2 caused a small but significant reduction in the SF cell protection. The lack of effect of EPHB2 knockdown may be due to the fact that DU-145 cells contain a single-mutant EPHB2 allele. A combination of three small interfering RNAs blocked most of the protection by SF in both DU-145 and T47D cells. These findings identify novel c-Akt-regulated genes, some of which contribute to SF-mediated cytoprotection.
- Published
- 2006
26. Identification of genes that modulate sensitivity of U373MG glioblastoma cells to cis-platinum
- Author
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John Laterra, Saijun Fan, Ren Qi Yuan, Changyan Hu, Eliot M. Rosen, Yongxian Ma, and Itzhak D. Goldberg
- Subjects
Cancer Research ,Angiogenesis ,Blotting, Western ,Genetic Vectors ,Down-Regulation ,Antineoplastic Agents ,Biology ,Transfection ,Cell Line, Tumor ,Glioma ,Gene expression ,medicine ,Humans ,Cytotoxic T cell ,Pharmacology (medical) ,RNA, Neoplasm ,RNA, Small Interfering ,Gene ,Protein kinase B ,Oligonucleotide Array Sequence Analysis ,Pharmacology ,Brain Neoplasms ,Hepatocyte Growth Factor ,NF-kappa B ,Proto-Oncogene Proteins c-met ,medicine.disease ,DNA Fingerprinting ,Molecular biology ,Gene Expression Regulation, Neoplastic ,Oncogene Protein v-akt ,Oncology ,Drug Resistance, Neoplasm ,Cancer research ,Hepatocyte growth factor ,Cisplatin ,DNA microarray ,Glioblastoma ,medicine.drug - Abstract
Scatter factor (hepatocyte growth factor) and its receptor c-Met are increasingly expressed during progression from low-grade to high-grade gliomas. Scatter factor/c-Met signaling induces glioma cell motility, invasion, angiogenesis and resistance to DNA-damaging agents. The latter is relevant to the understanding of the resistance of human gliomas to chemotherapy and radiotherapy. The goal of this study was to identify a set of genes that may contribute to scatter factor-mediated protection of U373MG cells against cis-platinum, a DNA cross-linking agent. We used DNA microarray assays, confirmatory semiquantitative reverse transcription-polymerase chain reaction analysis and functional assays to identify genes involved in the scatter factor-induced resistance of U373MG to cis-platinum. We identified a group of genes that are overexpressed in cells treated with scatter factor plus cis-platinum relative to cells treated with cis-platinum alone and confirmed some of these gene expression alterations by reverse transcription-polymerase chain reaction. Inhibiting the expression of three of these genes--polycystic kidney disease 1, amplified in breast cancer 1 and DEAD/H box helicase 21--using small interfering RNAs reduced survival of cis-platinum-treated cells and partially reversed the scatter factor protection against cis-platinum. Dominant-negative Akt and IkappaB super-repressor expression vectors inhibited the scatter factor protection, and abrogated the ability of scatter factor to alter the expression of DEAD/H box helicase 21 and polycystin (PKD1) within the context of cis-platinum exposure. The Akt and nuclear factor-kappaB inhibitors had no effect on amplified in breast cancer 1 expression. These studies implicate DEAD/H box helicase 21, polycystin (PKD1) and amplified in breast cancer 1 as novel transcription-dependent regulators of scatter factor-mediated glioma cell protection against cytotoxic death, and identify other potential regulators for future study.
- Published
- 2006
27. BRCA1 regulation of transcription
- Author
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Yongxian Ma, Saijun Fan, and Eliot M. Rosen
- Subjects
Cancer Research ,DNA Repair ,Transcription, Genetic ,endocrine system diseases ,Tumor suppressor gene ,Response element ,Breast Neoplasms ,Cell Cycle Proteins ,RNA polymerase II ,Biology ,Proto-Oncogene Proteins c-myb ,Sp3 transcription factor ,Animals ,Humans ,E2F1 ,STAT1 ,skin and connective tissue diseases ,Transcription factor ,Ovarian Neoplasms ,BRCA1 Protein ,Estrogen Receptor alpha ,TCF4 ,Gene Expression Regulation, Neoplastic ,STAT1 Transcription Factor ,Oncology ,Cancer research ,biology.protein ,Female ,Tumor Suppressor Protein p53 ,Apoptosis Regulatory Proteins - Abstract
BRCA1, a tumor suppressor gene on chromosome 17q21, was identified in 1994 based on its linkage to hereditary breast and ovarian cancer syndromes. The BRCA1 gene encodes a 220 kDa nuclear phosphoprotein. Studies aimed at elucidating the mechanisms of its tumor suppressor activity have revealed, in part, that BRCA1 participates in the DNA damage response and acts to maintain the integrity of the genome. This activity is generic and does not account for the propensity of BRCA1 mutation carriers to develop specific tumor types rather than a broad spectrum of cancers. In addition to genome maintenance, BRCA1 has been found to broadly regulate gene transcription, even though it is not itself a sequence-specific DNA-binding transcription factor. The ability of BRCA1 to function as a coregulator of transcription may underlie some of its tumor suppressor activity and may explain the tissue-specific nature of this activity. This review will focus on how BRCA1 selectively regulates transcription and how this regulatory function may relate to tumor suppression.
- Published
- 2006
28. The Breast Cancer Susceptibility Gene BRCA1 Regulates Progesterone Receptor Signaling in Mammary Epithelial Cells
- Author
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Yongxian Ma, Eliot M. Rosen, Yiyu Zhang, Laundette P. Jones, Pragati Katiyar, Saijun Fan, and Priscilla A. Furth
- Subjects
Small interfering RNA ,medicine.drug_class ,Biology ,Article ,Mice ,Mammary Glands, Animal ,Endocrinology ,Mammary tumor virus ,Cell Line, Tumor ,Progesterone receptor ,medicine ,Animals ,Humans ,Protein Isoforms ,p300-CBP Transcription Factors ,RNA, Small Interfering ,Promoter Regions, Genetic ,skin and connective tissue diseases ,Receptor ,Molecular Biology ,Progesterone ,Cell Proliferation ,Mice, Knockout ,Mammary tumor ,BRCA1 Protein ,Estrogen Receptor alpha ,Epithelial Cells ,General Medicine ,Gene Expression Regulation ,Mammary Tumor Virus, Mouse ,Estrogen ,Mutation ,Cancer research ,Signal transduction ,Receptors, Progesterone ,Estrogen receptor alpha ,Protein Binding ,Signal Transduction - Abstract
The progesterone receptor (PR) plays roles in normal mammary development and breast cancer formation, where it may exert both stimulatory and inhibitory actions. Previously, the breast cancer susceptibility gene product BRCA1 was found to interact with and inhibit the transcriptional activity of estrogen receptor-α. In this study, we found that exogenous wild-type BRCA1 inhibited the activity of the PR in transient transfection assays utilizing a mouse mammary tumor virus-Luc reporter. Wild-type BRCA1 inhibited the activity of endogenous PR in human breast cancer cells (T47D and MCF-7) and inhibited the activity of exogenous PR-A, PR-B, and [PR-A plus PR-B] isoforms. On the other hand, knockdown of endogenous BRCA1 using small interfering RNA enhanced the progesterone-stimulated activity of the PR by about 4-fold. We documented an in vivo association of the endogenous BRCA1 with PR isoforms A and B and a direct in vitro interaction between BRCA1 and PR, which was partially mapped. Whereas down-regulation of the coactivator p300 contributes to the BRCA1-mediated repression of estrogen receptor-α, this mechanism does not contribute to inhibition of PR activity, because exogenous p300 did not rescue the BRCA1 repression of PR activity. The BRCA1-PR interaction has functional consequences. Thus, we showed that BRCA1 inhibits the expression of various endogenous progesterone-responsive genes and inhibits progesterone-stimulated proliferation of T47D cells. Finally, exogenous progesterone caused an exaggerated proliferative response in the mammary glands of mice harboring a mammary-targeted conditional deletion of the full-length isoform of Brca1. These findings suggest that BRCA1 regulates the activity of progesterone, a major hormone of pregnancy that may also participate in mammary carcinogenesis.
- Published
- 2006
29. BRCA1 Regulates Gene Expression for Orderly Mitotic Progression
- Author
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Hee Jeong Kim, Alexander Kirilyuk, Bassem R. Haddad, Insoo Bae, Jeong Keun Rih, Hyo Jin Kang, Maria Laura Avantaggiati, Eliot M. Rosen, and Saijun Fan
- Subjects
Male ,Regulation of gene expression ,endocrine system diseases ,BRCA1 Protein ,Gene Expression Profiling ,Mitosis ,Prostatic Neoplasms ,Breast Neoplasms ,Cell Biology ,Biology ,Mitotic spindle checkpoint ,BUB1B ,Gene Expression Regulation, Neoplastic ,ASPM ,Spindle checkpoint ,Cell Line, Tumor ,Cancer research ,Humans ,Female ,PRC1 ,skin and connective tissue diseases ,Molecular Biology ,Cytokinesis ,Developmental Biology - Abstract
Germline mutations of the BRCA1 gene confer an increased risk for breast cancer and ovarian cancer. To study the contribution of BRCA1 to sporadic cancers, which often exhibit reduced BRCA1 expression, we tested the effect of knocking down BRCA1 on gene expression in human prostate (DU-145) and breast (MCF-7) cancer cells. DNA microarray and confirmatory RNA analyses revealed that BRCA1 small interfering (si) RNA caused down-regulation of multiple genes implicated in the mitotic spindle checkpoint (eg., BUB1B, HEC, and STK6), chromosome segregation (eg., ESPL1, NEK2, and PTTG1), centrosome function (eg., ASPM), cytokinesis (eg., PRC1, PLK, and KNSL2), and the progression into and through mitosis (eg., CDC2, and CDC20). Cells treated with BRCA1-siRNA showed attenuation of the mitotic spindle checkpoint; but not several G2 checkpoints. Finally, BRCA1 knockdown caused the accumulation of multinucleated cells, suggesting a defect in cytokinesis. We conclude that BRCA1 regulates gene expression for orderly mitotic progression.
- Published
- 2005
30. Role of NF-κB signaling in hepatocyte growth factor/scatter factor-mediated cell protection
- Author
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John Laterra, Marc Symons, Eliot M. Rosen, Richard G. Pestell, Saijun Fan, Itzhak D. Goldberg, Sal Coniglio, Qinghui Meng, and Min Gao
- Subjects
Cancer Research ,Transcription, Genetic ,medicine.medical_treatment ,Active Transport, Cell Nucleus ,Protein Serine-Threonine Kinases ,Biology ,Dogs ,PAK1 ,Proto-Oncogene Proteins ,Genetics ,medicine ,Animals ,Humans ,Tensin ,Protein kinase A ,Molecular Biology ,Cells, Cultured ,Hepatocyte Growth Factor ,Kinase ,Tumor Suppressor Proteins ,NF-kappa B ,PTEN Phosphohydrolase ,DNA ,TNF Receptor-Associated Factor 2 ,Molecular biology ,Phosphoric Monoester Hydrolases ,Cytokine ,p21-Activated Kinases ,Cytoprotection ,Doxorubicin ,Cancer research ,Hepatocyte growth factor ,Signal transduction ,Proto-Oncogene Proteins c-akt ,Signal Transduction ,medicine.drug ,Proto-oncogene tyrosine-protein kinase Src - Abstract
The cytokine scatter factor/hepatocyte growth factor (HGF/SF) protects epithelial, carcinoma, and other cell types against cytotoxicity and apoptosis induced by DNA-damaging agents such as ionizing radiation and adriamycin (ADR, a topoisomerase IIalpha inhibitor). We investigated the role of nuclear factor kappa B (NF-kappaB) signaling in HGF/SF-mediated protection of human prostate cancer (DU-145) and Madin-Darby canine kidney (MDCK) epithelial cells against ADR. HGF/SF caused the rapid nuclear translocation of the p65 (RelA) subunit of NF-kappaB associated with the transient loss of the inhibitory subunit IkappaB-alpha. Exposure to HGF/SF caused the activation of an NF-kappaB luciferase reporter that was blocked or attenuated by the expression of a mutant 'super-repressor' IkappaB-alpha. Electrophoretic mobility shift assay supershift assays revealed that HGF/SF treatment induced the transient binding of various NF-kappaB family proteins (p65, p50, c-Rel, and RelB) with radiolabeled NF-kappaB-binding oligonucleotides. The HGF/SF-mediated protection of DU-145 and MDCK cells against ADR (demonstrated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays) was abrogated by the IkappaB-alpha super-repressor. The ability of HGF/SF to activate NF-kappaB signaling was dependent on c-Akt --Pak1 (p21-associated kinase-1) signaling (with Pak1 downstream of c-Akt) and was inhibited by the tumor suppressor PTEN (phosphatase and tensin homolog). Inhibitors of phosphatidylinositol-3'-kinase and Src family kinases significantly inhibited HGF/SF-mediated activation of NF-kappaB, while inhibitors of MEK, protein kinase C, and p70 S6 kinase had a modest effect or no effect on NF-kappaB activity. HGF/SF induced the expression of several known NF-kappaB target genes (cIAP-1 (cellular inhibitor of apoptosis-1), cIAP-2, and TRAF-2 (TNF receptor-associated factor-2)) in an NF-kappaB-dependent manner; HGF/SF blocked the inhibition of expression of these genes by ADR. Experimental manipulation of expression of these genes suggests that they (particularly TRAF-2 and cIAP-2) contribute to the protection against ADR by HGF/SF. These findings suggest that HGF/SF activates NF-kappaB through a c-Akt --Pak1 signaling pathway that is also dependent on Src, and that NF-kappaB contributes to HGF/SF-mediated protection against ADR.
- Published
- 2005
31. Regulation of c-Met-dependent gene expression by PTEN
- Author
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Francisco Martinez-Murillo, John Laterra, Carlo Colantuoni, Thomas E. Reznik, Eliot M. Rosen, and Roger Abounader
- Subjects
Cancer Research ,C-Met ,Tumor suppressor gene ,medicine.disease_cause ,Receptor tyrosine kinase ,chemistry.chemical_compound ,Cell Line, Tumor ,Gene expression ,Genetics ,medicine ,Humans ,PTEN ,Molecular Biology ,Transcription factor ,Oligonucleotide Array Sequence Analysis ,biology ,Hepatocyte Growth Factor ,Tumor Suppressor Proteins ,PTEN Phosphohydrolase ,Proto-Oncogene Proteins c-met ,Transforming Growth Factor alpha ,Blotting, Northern ,Phosphoric Monoester Hydrolases ,ErbB Receptors ,Gene Expression Regulation, Neoplastic ,chemistry ,biology.protein ,Cancer research ,Hepatocyte growth factor ,Carcinogenesis ,medicine.drug - Abstract
Receptor tyrosine kinases (RTK) and the tumor suppressor PTEN co-regulate oncogenic cell signaling pathways. How these interactions influence gene transcription is inadequately understood. We used expression microarrays to investigate the effects of PTEN on gene expression changes caused by activating c-Met in human glioblastoma cells. c-Met activation by scatter factor/hepatocyte growth factor (SF/HGF) altered the expression of 27-fold more genes in PTEN-null U-373MG cells than in PTEN homozygous primary normal human astrocytes (523 vs 19 genes). Restoring wt-PTEN in U-373MG cells dramatically altered patterns of c-Met regulated gene expression. This effect was varied depending on the specific gene in question. PTEN reduced the number of c-Met regulated transcripts from 931 to 502, decreased the relative number of genes upregulated by c-Met from 46 to 25%, and increased the relative number of downregulated genes from 54 to 75%. PTEN and c-Met co-regulated many genes involved in cell growth regulation such as oncogenes, growth factors, transcription factors, and constituents of the ubiquitin pathway. c-Met activation in PTEN-null (but not PTEN reconstituted) cells led to upregulation of the EGFR agonist TGFalpha and subsequently to EGFR activation. Using PTEN mutants, we found that PTEN's transcriptional effects were either lipid-phosphatase dependent, protein-phosphatase dependent, or phosphatase-independent. These results show that PTEN has critical and mechanistically complex effects on RTK-regulated gene transcription. These findings expand our understanding of tumor promoter/suppressor inter-relationships and downstream transcriptional effects of PTEN loss and c-Met overexpression in malignant gliomas.
- Published
- 2004
32. BRCA1 Inhibits Membrane Estrogen and Growth Factor Receptor Signaling to Cell Proliferation in Breast Cancer
- Author
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Ali Pedram, Mahnaz Razandi, Ellis R. Levin, and Eliot M. Rosen
- Subjects
MAPK/ERK pathway ,endocrine system diseases ,medicine.medical_treatment ,Estrogen receptor ,Breast Neoplasms ,Biology ,Transfection ,Growth factor receptor ,Epidermal growth factor ,Cell Line, Tumor ,medicine ,Humans ,Receptors, Growth Factor ,Growth factor receptor inhibitor ,skin and connective tissue diseases ,Cell Growth and Development ,Molecular Biology ,Estradiol ,BRCA1 Protein ,Cell growth ,Growth factor ,Membrane Proteins ,Cell Biology ,Cell biology ,Receptors, Estrogen ,Mutation ,Cancer research ,Mitogen-Activated Protein Kinases ,Signal transduction ,Cell Division ,Signal Transduction - Abstract
BRCA1 mutations and estrogen use are risk factors for the development of breast cancer. Recent work has identified estrogen receptors localized at the plasma membrane that signal to cell biology. We examined the impact of BRCA1 on membrane estrogen and growth factor receptor signaling to breast cancer cell proliferation. MCF-7 and ZR-75-1 cells showed a rapid and sustained activation of extracellular signal-related kinase (ERK) in response to estradiol (E2) that was substantially prevented by wild-type (wt) but not mutant BRCA1. The proliferation of MCF-7 cells induced by E2 was significantly inhibited by PD98059, a specific ERK inhibitor, or by dominant negative ERK2 expression and by expression of wt BRCA1 (but not mutant BRCA1). E2 induced the synthesis of cyclins D1 and B1, the activity of cyclin-dependent kinases Cdk4 and CDK1, and G(1)/S and G(2)/M cell cycle progression. The intact tumor suppressor inhibited all of these. wt BRCA1 also inhibited epidermal growth factor and insulin-like growth factor I-induced ERK and cell proliferation. The inhibition of ERK and cell proliferation by BRCA1 was prevented by phosphatase inhibitors and by interfering RNA knockdown of the ERK phosphatase, mitogen-activated kinase phosphatase 1. Our findings support a novel tumor suppressor function of BRCA1 that is relevant to breast cancer and identify a potential interactive risk factor for women with BRCA1 mutations.
- Published
- 2004
33. Epithelial—Mesenchymal Interactions in Cancer
- Author
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Itzhak D. Goldberg, Eliot M. Rosen, Itzhak D. Goldberg, and Eliot M. Rosen
- Subjects
- Epithelium--Tumors, Mesenchyme--Pathophysiology, Cancer invasiveness, Carcinogenesis, Fibroblasts, Transforming growth factors, Epithelium--physiology, Mesoderm--physiology, Stromal Cells--physiology, Cell Transformation, Neoplastic
- Published
- 2013
34. BRCA1 in hormone-responsive cancers
- Author
-
Eliot M. Rosen, Itzhak D. Goldberg, Saijun Fan, and Richard G. Pestell
- Subjects
Male ,Hormone Responsive ,endocrine system diseases ,DNA repair ,Endocrinology, Diabetes and Metabolism ,Mammary gland ,Genes, BRCA1 ,Estrogen receptor ,Breast Neoplasms ,Biology ,medicine.disease_cause ,Mice ,Endocrinology ,Breast cancer ,Neoplasms ,medicine ,Animals ,Humans ,skin and connective tissue diseases ,Aged ,Mutation ,Multiple Endocrine Neoplasia ,Prostatic Neoplasms ,Cancer ,Middle Aged ,medicine.disease ,Gene Expression Regulation, Neoplastic ,Androgen receptor ,medicine.anatomical_structure ,Receptors, Estrogen ,Receptors, Androgen ,Cancer research ,Female - Abstract
Mutations of the breast cancer susceptibility gene BRCA1 are linked to hereditary early onset breast and breast–ovarian cancer syndromes. These mutations confer an increased risk for other hormone-dependent cancers, including those of the uterus, cervix and prostate. BRCA1 expression is decreased or absent in a significant proportion of sporadic breast and ovarian cancers, suggesting a wider role in these tumor types. Multiple functions for BRCA1 have been identified, including roles in DNA repair, cell-cycle progression and apoptosis. These functions are consistent with a tumor suppressor activity, but they do not explain why BRCA1 mutation carriers develop hormone-responsive cancer types. Recent studies indicate that BRCA1 interacts with and regulates the activity of estrogen receptor α (ERα) and the androgen receptor. Its expression is regulated by carcinogens and anticarcinogens that modulate ERα signaling, suggesting a molecular linkage between BRCA1 and hormone-responsive cancers.
- Published
- 2003
35. Response of Rat Skin to High-Dose Unidirectional X-Ray Microbeams: A Histological Study
- Author
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Tigran Bacarian, Nan Zhong, G. M. Morris, Eliot M. Rosen, and F. Avraham Dilmanian
- Subjects
Male ,Materials science ,Biophysics ,Dose distribution ,Radiation ,Radiation Dosage ,Radiation Tolerance ,Lower energy ,Conventional radiotherapy ,Microbeam radiation therapy ,Reference Values ,Animals ,Radiology, Nuclear Medicine and imaging ,Radiometry ,Skin ,business.industry ,X-Rays ,X-ray ,Dose-Response Relationship, Radiation ,Microbeam ,equipment and supplies ,Rats, Inbred F344 ,Hindlimb ,Rats ,Epidermal Cells ,Epidermis ,Nuclear medicine ,business ,Hair Follicle ,Beam energy - Abstract
There is growing interest in evaluating microbeam radiation therapy as a potential clinical modality. Microbeam radiation therapy uses arrays of parallel, microscopically thin (100 microm) planes of synchrotron-generated X rays (microplanar beams, or microbeams). Due to the relatively low beam energies involved in microbeam radiation therapy (a median beam energy of 120 keV was used in the present study), the dose penetration of microbeams in tissue is lower than that used in conventional radiotherapy. This lower energy necessitates using a significantly elevated dose to the skin's surface during clinical microbeam therapy to ensure an adequate dose distribution in the target tumor. The findings of the present study, using a rat skin model, indicated that the skin had an extremely high tolerance to microbeam radiation at doses considerably in excess of those that were therapeutically effective in preclinical studies. A histological study was undertaken to evaluate the biological mechanisms underlying this high tolerance. The irradiation configuration employed single-exposure, unidirectional microbeams 90 microm wide, with 300 microm beam spacing on-center. The in-beam skin-surface absorbed doses were in the range 835-1335 Gy. Monte Carlo simulations of the dose distribution indicated that the "valley" dose, i.e. the radiation leakage between adjacent microbeams, was about 2.5% of the in-beam dose. The high tolerance of the rats' skin to microbeams and the rapid regeneration of the damaged segments of skin were attributed to the surviving clonogenic cells situated between the adjacent microplanar beams. In the epidermis, clonogenic cells in the hair follicular epithelium appeared to play a key role in the regeneration process.
- Published
- 2003
36. Indole-3-Carbinol Is a Negative Regulator of Estrogen
- Author
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Leslie Goodwin, Timothy H. Carter, Karen J. Auborn, Eliot M. Rosen, Alamelu Chandraskaren, David E. Williams, Saijun Fan, and DaZhi Chen
- Subjects
Male ,medicine.medical_specialty ,Indoles ,medicine.drug_class ,DNA damage ,Uterine Cervical Neoplasms ,Medicine (miscellaneous) ,Estrogen receptor ,Diindolylmethane ,Genistein ,Antineoplastic Agents ,Apoptosis ,Breast Neoplasms ,Biology ,chemistry.chemical_compound ,Internal medicine ,Tumor Cells, Cultured ,medicine ,Indole-3-carbinol ,Humans ,Nutrition and Dietetics ,Estrogen Antagonists ,Drug Synergism ,Estrogens ,Endocrinology ,chemistry ,Estrogen ,Cancer cell ,Cancer research ,Female - Abstract
Studies increasingly indicate that dietary indole-3-carbinol (I3C) prevents the development of estrogen-enhanced cancers including breast, endometrial and cervical cancers. Epidemiological, laboratory, animal and translational studies support the efficacy of I3C. Whereas estrogen increases the growth and survival of tumors, I3C causes growth arrest and increased apoptosis and ameliorates the effects of estrogen. Our long-range goal is to best use I3C together with other nutrients to achieve maximum benefits for cancer prevention. This study examines the possibility that induction of growth arrest in response to DNA damage (GADD) in genes by diindolylmethane (DIM), which is the acid-catalyzed condensation product of I3C, promotes metabolically stressed cancer cells to undergo apoptosis. We evaluated whether genistein, which is the major isoflavonoid in soy, would alter the ability of I3C/DIM to cause apoptosis and decrease expression driven by the estrogen receptor (ER)-alpha. Expression of GADD was evaluated by real-time reverse transcription-polymerase chain reaction. Proliferation and apoptosis were measured by a mitochondrial function assay and by fluorescence-activated cell sorting analysis. The luciferase reporter assay was used to specifically evaluate expression driven by ER-alpha. The estrogen-sensitive MCF-7 breast cancer cell line was used for these studies. We show a synergistic effect of I3C and genistein for induction of GADD expression, thus increasing apoptosis, and for decrease of expression driven by ER-alpha. Because of the synergistic effect of I3C and genistein, the potential exists for prophylactic or therapeutic efficacy of lower concentrations of each phytochemical when used in combination.
- Published
- 2003
37. BRCA1 gene in breast cancer
- Author
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Eliot M. Rosen, Richard G. Pestell, Saijun Fan, and Itzhak D. Goldberg
- Subjects
endocrine system diseases ,Physiology ,DNA repair ,Clinical Biochemistry ,Genes, BRCA1 ,Breast Neoplasms ,Biology ,medicine.disease_cause ,Breast cancer ,medicine ,Animals ,Humans ,Amino Acid Sequence ,HSPA1L ,skin and connective tissue diseases ,Genetics ,Regulation of gene expression ,Mutation ,BRCA1 Protein ,Cancer ,Cell Biology ,Cell cycle ,medicine.disease ,HSPA1A ,Gene Expression Regulation, Neoplastic ,Disease Models, Animal ,Cancer research ,Female - Abstract
The BRCA1 gene was identified and cloned in 1994 based its linkage to early onset breast cancer and breast-ovarian cancer syndromes in women. While inherited mutations of BRCA1 are responsible for about 40-45% of hereditary breast cancers, these mutations account for only 2-3% of all breast cancers, since the BRCA1 gene is rarely mutated in sporadic breast cancers. However, BRCA1 expression is frequently reduced or absent in sporadic cancers, suggesting a much wider role in mammary carcinogenesis. Since BRCA1 was cloned in 1994, its molecular function has been the subject of intense investigation. These studies have revealed multiple functions of the BRCA1 that may contribute to its tumor suppressor activity, including roles in: cell cycle progression, several highly specialized DNA repair processes, DNA damage-responsive cell cycle check-points, regulation of a set of specific transcriptional pathways, and apoptosis. Many of these functions are linked to protein:protein interactions involving different portions of the 1,863 amino acid (aa) BRCA1 protein. BRCA1 functions in cell cycle progression and the DNA damage response appear to be regulated by distinct and specific phosphorylation events, but the molecular pathways activated by these phosphorylations are only beginning to be unraveled. In addition, the reason that BRCA1 mutation carriers develop specific tumor types (breast and ovarian cancers in women and possibly prostate cancers in men) is not clearly understood. Elucidation of the precise molecular functions of the BRCA1 gene product will greatly enhance our understanding of the pathogenesis of hereditary as well as sporadic mammary carcinogenesis.
- Published
- 2003
38. Pretreatment of indole-3-carbinol augments TRAIL-induced apoptosis in a prostate cancer cell line, LNCaP
- Author
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Eliot M. Rosen, Jeong-Keun Rih, Chi-Heum Cho, Kye-Im Jeon, Hee Jeong Kim, Itzhak D. Goldberg, Yong J. Lee, and Insoo Bae
- Subjects
Male ,Programmed cell death ,Indoles ,Time Factors ,Death receptor 5 ,Death receptor 4 ,Blotting, Western ,Biophysics ,Tetrazolium Salts ,Apoptosis ,Biology ,Biochemistry ,Antioxidants ,Receptors, Tumor Necrosis Factor ,TNF-Related Apoptosis-Inducing Ligand ,chemistry.chemical_compound ,Prostate cancer ,Structural Biology ,LNCaP ,Tumor Cells, Cultured ,Genetics ,Indole-3-carbinol ,medicine ,Humans ,Viability assay ,Decoy receptors ,Coloring Agents ,Chemosensitivity ,Molecular Biology ,Membrane Glycoproteins ,Cell Death ,Reverse Transcriptase Polymerase Chain Reaction ,Tumor Necrosis Factor-alpha ,Prostatic Neoplasms ,Free Radical Scavengers ,Cell Biology ,medicine.disease ,Molecular biology ,Receptors, TNF-Related Apoptosis-Inducing Ligand ,Thiazoles ,chemistry ,Cancer research ,Tumor necrosis factor alpha ,Apoptosis Regulatory Proteins - Abstract
Prostate cancer is one of the most common cancers in men and is the second leading cause of cancer-related deaths in the USA. Many anti-tumor agents against prostate cancer cells have been developed, but their unacceptable systemic toxicity to normal tissues frequently limits their usage in clinics. Several previous studies have demonstrated that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce cell death in a variety of transformed cells including prostate cancer cells, but not normal cells. Indole-3-carbinol (I3C), a phytochemical that is produced in fruits and vegetables, may play an important role in the prevention of many types of cancer, including hormone-related ones such as breast and prostate cancer. In this study, we examined the potential sensitizing effects of I3C on TRAIL-mediated apoptosis in a prostate cancer cell line, LNCaP. When LNCaP cells were incubated with I3C (either 30 or 90 μM) for 24 h and then treated with TRAIL (100 ng/ml), enhanced TRAIL-mediated apoptosis was observed. The enhanced apoptosis measured by poly(ADP-ribose) polymerase and caspase 3 cleavage. We also observed that loss of cell viability after treatment with I3C/TRAIL is greater compared with I3C and TRAIL alone. To determine the molecular mechanisms involved in the enhanced apoptosis, we examined the expression of two TRAIL death receptors (DR4 and DR5) and two TRAIL decoy receptors (DcR1 and DcR2). We found that treatment with I3C induced DR4 and DR5 expression at both transcriptional and translational levels. These findings suggest that I3C may be an effective sensitizer of TRAIL treatment against TRAIL-resistant prostate cancer cell lines such as LNCaP.
- Published
- 2003
39. Murine EMT-6 Carcinoma: High Therapeutic Efficacy of Microbeam Radiation Therapy
- Author
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Jennifer Tammam, John Kalef-Ezra, F. Avraham Dilmanian, Eliot M. Rosen, G. M. Morris, James F. Hainfeld, Laura J. Brewington, Nan Zhong, and Tigran Bacarian
- Subjects
High rate ,Mice, Inbred BALB C ,Radiation ,business.industry ,medicine.medical_treatment ,Biophysics ,Mammary Neoplasms, Experimental ,Radiotherapy Dosage ,X-Ray Therapy ,equipment and supplies ,medicine.disease ,Radiation Tolerance ,Radiation therapy ,Mice ,Microbeam radiation therapy ,medicine ,Carcinoma ,Animals ,Female ,Radiology, Nuclear Medicine and imaging ,Nuclear medicine ,business ,Synchrotrons - Abstract
Microbeam radiation therapy is an experimental modality using parallel arrays of thin (100 micro m) slices of synchrotron-generated X rays (microplanar beams, microbeams). We used EMT-6 murine mammary carcinoma subcutaneously inoculated in the hind legs of mice to compare the therapeutic efficacies of single-fraction, unidirectional (1) "co-planar" microbeams (an array of vertically oriented microplanar beams), (2) "cross-planar" microbeams (two arrays of parallel microbeams propagated in the same direction, one with vertically and the other with horizontally oriented microplanar beams), and (3) seamless (broad) beams from the same synchrotron source. The microbeams were 90 micro m wide and were spaced 300 micro m on center; the median energy in all beams was 100 or 118 keV. Tumor ablation rates were 4/8, 4/8 and 6/7 for a 410-, 520- and 650-Gy in-slice cross-planar microbeam dose, respectively, and 1/8, 3/8, 3/7 and 6/8 for a 23-, 30-, 38- and 45-Gy broad-beam dose, respectively. When the data were pooled from the three highest doses (same average tumor ablations of 50-60%), the incidences of normal-tissue acute toxicity (moist desquamation and epilation) and delayed toxicity (failure of hair regrowth) were significantly lower for cross-planar microbeams than broad beams (P0.025). Furthermore, for the highest doses in these two groups, which also had the same tumor ablation rate (75%), not only were the above toxicities lower for the cross-planar microbeams than for the broad beams (P0.02), but severe leg dysfunction was also lower (P0.003). These findings suggest that single-fraction microbeams can ablate tumors at high rates with relatively little normal-tissue toxicity.
- Published
- 2003
40. Abstract 3602: Novel BRCA1 mimetic 35446HCl inhibits growth of anti estrogen resistant breast cancer cells through the NF-κB pathway
- Author
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Shyam Nathan and Eliot M. Rosen
- Subjects
Hormone response element ,Cancer Research ,Programmed cell death ,Chemistry ,Estrogen receptor ,NF-κB ,Antiestrogen ,medicine.disease ,chemistry.chemical_compound ,Breast cancer ,Oncology ,Mechanism of action ,Cancer research ,medicine ,medicine.symptom ,Signal transduction - Abstract
Nearly a third of breast cancer patients develop resistance to antiestrogen treatments although the estrogen receptor ER-α continues to affect cell survival and proliferation. Thus there is a need for new interventions to inhibit ER-α function. Based on high-resolution mapping, we proposed interaction sites on both BRCA1 and ER-α in a three-dimensional model of BRCA1. Utilizing this model, we identified a class of compounds that fits into a predicted BRCA1-binding cavity within ER-α, mimics the ability of BRCA1 to repress ER-α activity, and functions differently than other antiestrogens. Previous publication has shown that the 1st generation BRCA1 mimetic compound (A7) reduced proliferation and inhibited ER-α activity in antiestrogen-sensitive and resistant breast cancer cells with negligible non-specific toxicity. More importantly we have shown that the 2nd generation compounds (35446, 4631) partially restored sensitivity to Tam/ICI-resistant cells (LCC9), caused dissociation of ER-α from a model estrogen response element (ERE) in MCF-7 cells, and inhibited growth of LCC9 tumor xenografts at nontoxic concentrations utilizing compound 35446-HCl (35446 prepared as a hydrochloride salt). The focus of this study is the mechanism of action of 35446-HCl compound’s inhibition of ER-α, which includes inhibition of a major signaling pathway and mode of cell death. Eight genes identified from RNA-seq in LCC9 cells treated with BRCA1 mimetic A7 were verified by qPCR using 35446-HCl. One verified gene is the NF-κB activator IKKB, which is linked to therapy resistance. Treatment with 35446-HCl inhibited IKKB expression and proliferation in LCC9 cells compared to untreated Control at 48 and 72 hrs (p Citation Format: Shyam Nathan, Eliot M. Rosen. Novel BRCA1 mimetic 35446HCl inhibits growth of anti estrogen resistant breast cancer cells through the NF-κB pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3602. doi:10.1158/1538-7445.AM2017-3602
- Published
- 2017
41. Small-Molecule 'BRCA1-Mimetics' Are Antagonists of Estrogen Receptor-α
- Author
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Eliseu O. De Oliveira, Anju Preet, Eliot M. Rosen, Scott Grindrod, Shyam Nathan, Milton L. Brown, Erikah Englund, Robert Clarke, York Tomita, and Yongxian Ma
- Subjects
Selective Estrogen Receptor Modulators ,medicine.drug_class ,Ubiquitin-Protein Ligases ,Estrogen receptor ,Pharmacology ,Biology ,Endocrinology ,Estrogen Receptor Modulators ,Cell Line, Tumor ,Coactivator ,medicine ,Humans ,Molecular Biology ,Estrogen receptor beta ,Original Research ,Estrogen Antagonists ,Estrogen Receptor alpha ,General Medicine ,Surface Plasmon Resonance ,Tamoxifen ,Estrogen ,Selective estrogen receptor modulator ,Pharmacophore ,Estrogen receptor alpha ,medicine.drug ,Protein Binding - Abstract
Context: Resistance to conventional antiestrogens is a major cause of treatment failure and, ultimately, death in breast cancer. Objective: The objective of the study was to identify small-molecule estrogen receptor (ER)-α antagonists that work differently from tamoxifen and other selective estrogen receptor modulators. Design: Based on in silico screening of a pharmacophore database using a computed model of the BRCA1-ER-α complex (with ER-α liganded to 17β-estradiol), we identified a candidate group of small-molecule compounds predicted to bind to a BRCA1-binding interface separate from the ligand-binding pocket and the coactivator binding site of ER-α. Among 40 candidate compounds, six inhibited estradiol-stimulated ER-α activity by at least 50% in breast carcinoma cells, with IC50 values ranging between 3 and 50 μM. These ER-α inhibitory compounds were further studied by molecular and cell biological techniques. Results: The compounds strongly inhibited ER-α activity at concentrations that yielded little or no nonspecific toxicity, but they produced only a modest inhibition of progesterone receptor activity. Importantly, the compounds blocked proliferation and inhibited ER-α activity about equally well in antiestrogen-sensitive and antiestrogen-resistant breast cancer cells. Representative compounds disrupted the interaction of BRCA1 and ER-α in the cultured cells and blocked the interaction of ER-α with the estrogen response element. However, the compounds had no effect on the total cellular ER-α levels. Conclusions: These findings suggest that we have identified a new class of ER-α antagonists that work differently from conventional antiestrogens (eg, tamoxifen and fulvestrant).
- Published
- 2014
42. Mutant BRCA1 genes antagonize phenotype of wild-type BRCA1
- Author
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Itzhak D. Goldberg, Qinghui Meng, Eliot M. Rosen, Yong Xian Ma, Saijun Fan, and Ren-qi Yuan
- Subjects
Male ,Cancer Research ,DNA Repair ,endocrine system diseases ,DNA repair ,DNA damage ,Mutant ,Genes, BRCA1 ,Apoptosis ,Breast Neoplasms ,Biology ,Transfection ,medicine.disease_cause ,Tumor Cells, Cultured ,Genetics ,medicine ,Humans ,skin and connective tissue diseases ,Molecular Biology ,Mutation ,BRCA1 Protein ,Estrogen Receptor alpha ,Wild type ,Prostatic Neoplasms ,DNA, Neoplasm ,Neoplasm Proteins ,Phenotype ,Receptors, Estrogen ,Drug Resistance, Neoplasm ,Cancer cell ,Cancer research ,Female ,Carcinogenesis ,Cell Division ,DNA Damage - Abstract
Unregulated expression of wild-type BRCA1 (wtBRCA1) confers an altered phenotype in cultured human prostate cancer cells, characterized by chemosensitivity, susceptibility to apoptosis, decreased DNA repair activity, and alterations of key cell regulatory proteins. We now report that the expression of truncated or mutant full-length BRCA1 genes can abrogate certain phenotypic characteristics and/or confer the opposite phenotype to the wild-type BRCA1 gene. In particular, several carboxyl-terminal truncated BRCA1 proteins conferred chemoresistance, decreased susceptibility to apoptosis, and decreased ability to suppress in vivo tumor growth. These truncated BRCA1 proteins also blocked the ability of ectopically expressed wtBRCA1 to induce chemosensitivity and to inhibit estrogen receptor transcriptional activity. Studies using epitope-tagged truncated proteins confirmed their expression, nuclear localization, and functionality. On the other hand, in cells with no endogenous wild-type BRCA1 (HCC1937 human breast cancer cells), the wtBRCA1 gene enhanced cellular DNA repair activity and rendered the cells resistant to DNA damage; while truncated BRCA1 proteins blocked the wtBRCA1-induced chemoresistance. Our findings suggest that truncated BRCA1 proteins can inhibit the function of wild-type BRCA1. They raise the possibility that some inherited BRCA1 mutations may actively promote oncogenesis by blocking the function of the remaining wild-type BRCA1 allele, although this hypothesis remains to be proved.
- Published
- 2001
43. In vivo targeting of SF/HGF and c‐met expression via U1snRNA/ribozymes inhibits glioma growth and angiogenesis and promotes apoptosis
- Author
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Carey Luddy, Gary Koe, Eliot M. Rosen, Roger Abounader, John Laterra, Beverly L. Davidson, and Bachchu Lal
- Subjects
C-Met ,Angiogenesis ,medicine.medical_treatment ,Genetic Vectors ,Molecular Sequence Data ,Apoptosis ,Biology ,Biochemistry ,DNA, Antisense ,Adenoviridae ,Mice ,chemistry.chemical_compound ,In vivo ,RNA, Small Nuclear ,Glioma ,Radioresistance ,Tumor Cells, Cultured ,Genetics ,medicine ,Animals ,Humans ,RNA, Catalytic ,RNA, Neoplasm ,Transgenes ,Molecular Biology ,Base Sequence ,Neovascularization, Pathologic ,Brain Neoplasms ,Hepatocyte Growth Factor ,Growth factor ,Ribozyme ,Proto-Oncogene Proteins c-met ,medicine.disease ,Xenograft Model Antitumor Assays ,Molecular biology ,chemistry ,Cancer research ,biology.protein ,Hepatocyte growth factor ,Glioblastoma ,Cell Division ,Biotechnology ,medicine.drug - Abstract
The multifunctional growth factor scatter factor/hepatocyte growth factor (SF/HGF) and its receptor c-met have been implicated in the genesis, malignant progression, and chemo/radioresistance of multiple human malignancies, including gliomas. We examined the antitumor effects of targeting SF/HGF and c-met expression in pre-established glioma xenografts by using novel chimeric U1snRNA/ribozymes. Transient expression of anti-SF/HGF and anti-c-met U1snRNA/ribozymes inhibited SF/HGF and c-met expression, c-met receptor activation, tumor cell migration, and anchorage-independent colony formation in vitro. Delivery of U1snRNA/ribozymes to established subcutaneous glioma xenografts via liposome-DNA complexes significantly inhibited tumor growth as well as tumor SF/HGF and c-met expression levels. Histologic analysis of tumors treated with U1snRNA/ribozymes showed a significant decrease in blood vessel density, an increase in activation of the pro-apoptotic enzyme caspase-3, and an increase in tumor cell apoptosis. Treatment of animals bearing intracranial glioma xenografts with anti-SF/HGF and anti-c-met U1snRNA/ribozymes by either intratumoral injections of adenoviruses expressing the transgenes or intravenous injections of U1snRNA/ribozyme-liposome complexes substantially inhibited tumor growth and promoted animal survival. We demonstrate that SF/HGF and/or c-met expression can be targeted in vivo to inhibit tumor growth. In addition, our findings represent the first in vivo application of chimeric U1snRNA/ribozymes, which have numerous potential therapeutic gene-targeting applications.
- Published
- 2001
44. Disruption of BRCA1 LXCXE motif alters BRCA1 functional activity and regulation of RB family but not RB protein binding
- Author
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Itzhak D. Goldberg, Eliot M. Rosen, Yong Xian Ma, Michael R. Erdos, Jian-Nian Zhao, Ren-qi Yuan, Saijun Fan, Qinghui Meng, Richard G. Pestell, and Jingbo Xiong
- Subjects
Cancer Research ,Cell cycle checkpoint ,Amino Acid Motifs ,Molecular Sequence Data ,Down-Regulation ,Biology ,Retinoblastoma Protein ,Cyclin D1 ,Downregulation and upregulation ,Tumor Cells, Cultured ,Genetics ,medicine ,Humans ,Amino Acid Sequence ,Genes, Retinoblastoma ,Binding site ,skin and connective tissue diseases ,Molecular Biology ,Peptide sequence ,Binding Sites ,BRCA1 Protein ,Retinoblastoma ,Nuclear Proteins ,medicine.disease ,In vitro ,Cell biology ,BRCT domain ,Trans-Activators - Abstract
The tumor suppressor activity of the BRCA1 gene product is due, in part, to functional interactions with other tumor suppressors, including p53 and the retinoblastoma (RB) protein. RB binding sites on BRCA1 were identified in the C-terminal BRCT domain (Yarden and Brody, 1999) and in the N-terminus (aa 304-394) (Aprelikova et al., 1999). The N-terminal site contains a consensus RB binding motif, LXCXE (aa 358-362), but the role of this motif in RB binding and BRCA1 functional activity is unclear. In both in vitro and in vivo assays, we found that the BRCA1:RB interaction does not require the BRCA1 LXCXE motif, nor does it require an intact A/B binding pocket of RB. In addition, nuclear co-localization of the endogenous BRCA1 and RB proteins was observed. Over-expression of wild-type BRCA1 (wtBRCA1) did not cause cell cycle arrest but did cause down-regulation of expression of RB, p107, p130, and other proteins (e.g., p300), associated with increased sensitivity to DNA-damaging agents. In contrast, expression of a full-length BRCA1 with an LXCXE inactivating mutation (LXCXE-->RXRXH) failed to down-regulate RB, blocked the down-regulation of RB by wtBRCA1, induced chemoresistance, and abrogated the ability of BRCA1 to mediate tumor growth suppression of DU-145 prostate cancer cells. wtBRCA1-induced chemosensitivity was partially reversed by expression of either Rb or p300 and fully reversed by co-expression of Rb plus p300. Our findings suggest that: (1) disruption of the LXCXE motif within the N-terminal RB binding region alters the biologic function of BRCA1; and (2) over-expression of BRCA1 inhibits the expression of RB and RB family (p107 and p130) proteins.
- Published
- 2001
45. The Multisubstrate Adapter Gab1 Regulates Hepatocyte Growth Factor (Scatter Factor)–c-Met Signaling for Cell Survival and DNA Repair
- Author
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Yong Xian Ma, Itzhak D. Goldberg, Min Gao, Qinghui Meng, Saijun Fan, Ren-qi Yuan, and Eliot M. Rosen
- Subjects
Time Factors ,DNA Repair ,Tetrazolium Salts ,Apoptosis ,Wortmannin ,Phosphatidylinositol 3-Kinases ,chemistry.chemical_compound ,Cell Movement ,Enzyme Inhibitors ,Phosphorylation ,Cell Growth and Development ,Caspase 3 ,Hepatocyte Growth Factor ,Proto-Oncogene Proteins c-met ,Recombinant Proteins ,Pleckstrin homology domain ,Caspases ,Hepatocyte growth factor ,Signal transduction ,Cell Division ,Protein Binding ,Signal Transduction ,medicine.drug ,C-Met ,Cell Survival ,DNA repair ,Blotting, Western ,Genetic Vectors ,DNA Fragmentation ,Protein Serine-Threonine Kinases ,Biology ,Transfection ,Models, Biological ,Cell Line ,Dogs ,Proto-Oncogene Proteins ,medicine ,Animals ,Humans ,Molecular Biology ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Adaptor Proteins, Signal Transducing ,GRB2 Adaptor Protein ,Binding Sites ,Proteins ,Epithelial Cells ,DNA ,Cell Biology ,Phosphoproteins ,Precipitin Tests ,Protein Structure, Tertiary ,Androstadienes ,Thiazoles ,p21-Activated Kinases ,chemistry ,Doxorubicin ,Mutation ,Cancer research ,Proto-Oncogene Proteins c-akt ,DNA Damage - Abstract
Hepatocyte growth factor (scatter factor) (HGF/SF) is a pleiotrophic mediator of epithelial cell motility, morphogenesis, angiogenesis, and tumorigenesis. HGF/SF protects cells against DNA damage by a pathway from its receptor c-Met to phosphatidylinositol 3-kinase (PI3K) to c-Akt, resulting in enhanced DNA repair and decreased apoptosis. We now show that protection against the DNA-damaging agent adriamycin (ADR; topoisomerase IIalpha inhibitor) requires the Grb2-binding site of c-Met, and overexpression of the Grb2-associated binder Gab1 (a multisubstrate adapter required for epithelial morphogenesis) inhibits the ability of HGF/SF to protect MDCK epithelial cells against ADR. In contrast to Gab1 and its homolog Gab2, overexpression of c-Cb1, another multisubstrate adapter that associates with c-Met, did not affect protection. Gab1 blocked the ability of HGF/SF to cause the sustained activation of c-Akt and c-Akt signaling (FKHR phosphorylation). The Gab1 inhibition of sustained c-Akt activation and of cell protection did not require the Gab1 pleckstrin homology or SHP2 phosphatase-binding domain but did require the PI3K-binding domain. HGF/SF protection of parental MDCK cells was blocked by wortmannin, expression of PTEN, and dominant negative mutants of p85 (regulatory subunit of PI3K), Akt, and Pak1; the protection of cells overexpressing Gab1 was restored by wild-type or activated mutants of p85, Akt, and Pak1. These findings suggest that the adapter Gab1 may redirect c-Met signaling through PI3K away from a c-Akt/Pak1 cell survival pathway.
- Published
- 2001
46. Role of direct interaction in BRCA1 inhibition of estrogen receptor activity
- Author
-
Peter J. Kushner, Itzhak D. Goldberg, Eliot M. Rosen, Saijun Fan, Paul Webb, Michael Erdos, Ren Qi Yuan, Yong Xian Ma, Qinghui Meng, Richard G. Pestell, Chenguang Wang, and Ji An Wang
- Subjects
Cancer Research ,medicine.medical_specialty ,Transcription, Genetic ,endocrine system diseases ,Tumor suppressor gene ,Recombinant Fusion Proteins ,Transgene ,Genes, BRCA1 ,Estrogen receptor ,Breast Neoplasms ,Biology ,Internal medicine ,Gene expression ,Tumor Cells, Cultured ,Genetics ,medicine ,Humans ,skin and connective tissue diseases ,Receptor ,Estrogen receptor activity ,Molecular Biology ,Glutathione Transferase ,Sequence Deletion ,Binding Sites ,BRCA1 Protein ,Estrogen Receptor alpha ,Chromosome Mapping ,Peptide Fragments ,Cell biology ,Endocrinology ,Receptors, Estrogen ,Mutation ,Cancer cell ,Estrogen receptor alpha - Abstract
The BRCA1 gene was previously found to inhibit the transcriptional activity of the estrogen receptor [ER-alpha] in human breast and prostate cancer cell lines. In this study, we found that breast cancer-associated mutations of BRCA1 abolish or reduce its ability to inhibit ER-alpha activity and that domains within the amino- and carboxyl-termini of the BRCA1 protein are required for the inhibition. BRCA1 inhibition of ER-alpha activity was demonstrated under conditions in which a BRCA1 transgene was transiently or stably over-expressed in cell lines with endogenous wild-type BRCA1 and in a breast cancer cell line that lacks endogenous functional BRCA1 (HCC1937). In addition, BRCA1 blocked the expression of two endogenous estrogen-regulated gene products in human breast cancer cells: pS2 and cathepsin D. The BRCA1 protein was found to associate with ER-alpha in vivo and to bind to ER-alpha in vitro, by an estrogen-independent interaction that mapped to the amino-terminal region of BRCA1 (ca. amino acid 1-300) and the conserved carboxyl-terminal activation function [AF-2] domain of ER-alpha. Furthermore, several truncated BRCA1 proteins containing the amino-terminal ER-alpha binding region blocked the ability of the full-length BRCA1 protein to inhibit ER-alpha activity. Our findings suggest that the amino-terminus of BRCA1 interacts with ER-alpha, while the carboxyl-terminus of BRCA1 may function as a transcriptional repression domain. Oncogene (2001) 20, 77 - 87.
- Published
- 2001
47. Inhibitory effects of Indole-3-carbinol on invasion and migration in human breast cancer cells
- Author
-
Eliot M. Rosen, Itzhak D. Goldberg, Saijun Fan, and Qinghui Meng
- Subjects
CA15-3 ,Cancer Research ,Pathology ,medicine.medical_specialty ,Indoles ,Tumor suppressor gene ,Breast Neoplasms ,Biology ,Metastasis ,Breast cancer ,Cell Movement ,Cell Adhesion ,Tumor Cells, Cultured ,medicine ,Anticarcinogenic Agents ,Humans ,PTEN ,Neoplasm Invasiveness ,skin and connective tissue diseases ,Tumor Suppressor Proteins ,PTEN Phosphohydrolase ,Cadherins ,medicine.disease ,Metastatic breast cancer ,Phosphoric Monoester Hydrolases ,Oncology ,Tumor progression ,Cancer cell ,biology.protein ,Cancer research ,Female - Abstract
Indole-3-carbinol (I3C) is a promising phytochemical agent in chemoprevention of breast cancer. Our present study is the first description of I3C that significantly inhibits the cell adhesion, spreading and invasion associated with an up-regulation of PTEN (a tumor suppressor gene) and E-cadherin (a regulator of cell-cell adhesion) expression in T47-D human breast cancer cells. Therefore, I3C exhibits anti-cancer activities by suppressing breast tumor cell growth and metastatic spread. Metastatic breast cancer is a devastating problem, clinical application of I3C as a potent chemopreventive agent may be helpful in limiting breast cancer invasion and metastasis.
- Published
- 2000
48. Stimulation of Cell Invasion and Migration by Alcohol in Breast Cancer Cells
- Author
-
Bin Gao, Saijun Fan, Qinghui Meng, Itzhak D. Goldberg, and Eliot M. Rosen
- Subjects
Alcohol Drinking ,Genes, BRCA1 ,Biophysics ,Gene Expression ,Breast Neoplasms ,Stimulation ,medicine.disease_cause ,Biochemistry ,Breast Cancer Risk Factor ,Breast cancer ,Cell Movement ,Risk Factors ,Cell Adhesion ,Tumor Cells, Cultured ,medicine ,Humans ,Neoplasm Invasiveness ,RNA, Messenger ,RNA, Neoplasm ,skin and connective tissue diseases ,Cell adhesion ,Molecular Biology ,Ethanol ,Cadherin ,business.industry ,Cell Biology ,Cadherins ,medicine.disease ,Cytoskeletal Proteins ,Catenin ,Immunology ,Cancer cell ,Cancer research ,Female ,Carcinogenesis ,business - Abstract
Increasing epidemiological studies suggest that alcohol consumption confers a high risk for development of breast cancer. In this study, we found that biologically relevant concentrations of alcohol elicited a significant stimulation of cell adhesion, migration, and invasion in MCF-7 human breast cancer cells. Moreover, the promotion of invasion and migration potential by alcohol was associated with the significant decrease of E-cadherin, alpha, beta, and gamma three major catenin, and BRCA1 expression. In addition, an enhanced expression of BRCA1 significantly blocked alcohol-stimulated cell invasion. Thus, our present study suggests that alcohol as a breast cancer risk factor plays an important role not only in carcinogenesis, but also in promotion of cell invasion and migration.
- Published
- 2000
49. Suppression of breast cancer invasion and migration by indole-3-carbinol: associated with up-regulation of BRCA1 and E-cadherin/catenin complexes
- Author
-
Saijun Fan, Qinghui Meng, Eliot M. Rosen, Karen J. Auborn, DaZhi Chen, Ren-qi Yuan, Itzhak D. Goldberg, and Mei Qi
- Subjects
Indoles ,Lung Neoplasms ,Time Factors ,Genes, BRCA1 ,Estrogen receptor ,Breast Neoplasms ,Biology ,Metastasis ,chemistry.chemical_compound ,Breast cancer ,Cell Movement ,Drug Discovery ,Cell Adhesion ,Tumor Cells, Cultured ,medicine ,Indole-3-carbinol ,Anticarcinogenic Agents ,Humans ,Neoplasm Invasiveness ,RNA, Messenger ,skin and connective tissue diseases ,Cell adhesion ,beta Catenin ,Genetics (clinical) ,Dose-Response Relationship, Drug ,Estradiol ,BRCA1 Protein ,Reverse Transcriptase Polymerase Chain Reaction ,Cadherin ,Cell migration ,Cadherins ,medicine.disease ,Up-Regulation ,Cytoskeletal Proteins ,Desmoplakins ,chemistry ,Catenin ,Immunology ,Trans-Activators ,Cancer research ,Molecular Medicine ,Female ,gamma Catenin ,Neoplasm Transplantation ,alpha Catenin - Abstract
Indole-3-carbinol (I3C) is a compound occurring naturally in cruciferous vegetables and has been indicated as a promising agent in preventing breast cancer development and progression. In the present study we have investigated the effect of I3C on the cell migration and invasion behavior in estrogen receptor positive MCF-7 and estrogen receptor negative MDA-MB-468 human breast cancer cell lines. Both MCF-7 and MDA-MB-468 were poorly invasive cell lines and exhibited modest invasion and migration capacity in the presence of fibronectin as the chemoattractant. I3C (50 or 100 microM) elicited a significant inhibition of in vitro cell adhesion, migration, and invasion as well as in vivo lung metastasis formation in both cell lines. I3C also suppressed the 17beta-estradiol stimulated migration and invasion in estrogen-responsive MCF-7 cells. These results indicate that anti-invasion and antimigration activities of I3C occur via estrogen-independent and estrogen-dependent pathways. Moreover, I3C significantly caused a dose-dependent increase in E-cadherin, three major catenins (alpha, beta, and gamma-catenin) and BRCA1 expression. Our current finding is the first demonstration that I3C can activate the function of invasion suppressor molecules associated with the suppression of invasion and migration in breast cancer cells. Thus, clinical application of I3C may contribute to the potential benefit for suppression of breast cancer invasion and metastasis.
- Published
- 2000
50. [Untitled]
- Author
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Eliot M. Rosen, Itzhak D. Goldberg, Robert A. Greenwald, Qinghui Meng, Jingwen Xu, and Saijun Fan
- Subjects
Oncology ,congenital, hereditary, and neonatal diseases and abnormalities ,Cancer Research ,medicine.medical_specialty ,Beta-catenin ,MDA-MB-468 ,Cell migration ,General Medicine ,Biology ,medicine.disease ,In vitro ,nervous system diseases ,Metastasis ,Breast cancer ,Catenin ,Internal medicine ,Cancer cell ,medicine ,biology.protein ,Cancer research - Abstract
Chemically modified tetracyclines (CMTs) are promising anti-cancer agents. In this study, we found that CMT-3 and CMT-8 showed dose-dependent cytotoxicities in MDA-MB-468 human breast cancer cells. Moreover, both CMT-3 and CMT-8 significantly inhibited in vitro cell migration and invasion at non-cytotoxic concentrations. Anti-invasion and migration potentials of the CMTs were associated with an increased expression of E-cadherin/catenins (alpha, beta and gamma-catenin) and tumor suppressor BRCA1. In addition, CMT-3 and CMT-8 abolished or reduced spontaneous and HGF/SF-induced cell invasion and migration in U-373 MG human glioblastoma cells. Our current finding is the first demonstration that CMT-3 and CMT-8 can activate the function of invasion suppressor molecules associated with the suppression of breast cancer cell invasion and migration. Thus, clinical application of CMTs may provide potential benefit for suppression of breast cancer growth, invasion and metastasis.
- Published
- 2000
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