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Chromosomal abnormalities that involve the MYCN gene are rare; however, it is one of the most commonly mutated genes in retinoblastoma (RB) after the RB1 gene. MYCN is amplified in approximately 1–9 % of all RB tumors. It plays a role in RB oncogenesis via many mechanisms, including synergism with RB1 deletion, positive feedback with MDM2, upregulation of cell cycle regulating genes, upregulation of miRNA, and upregulation of glucose metabolism. MYCN amplifications are not mutually exclusive and can occur even in the presence of RB1 gene mutations. Clinically, RB1+/+MYCNA tumors present as sporadic, unilateral, advanced tumors in very young children and tend to follow an aggressive course. Magnetic resonance imaging features include peripheral tumor location, placoid configuration, retinal folding, tumor-associated hemorrhage, and anterior chamber enhancement. Genetic testing for MYCNA is especially recommended in patients with unilateral RB where genetic blood testing and tumor tissue show a lack of RB1 mutation. MYCN-targeted therapies are evolving and hold promise for the future. [ABSTRACT FROM AUTHOR]

In this current investigation, a straightforward method is presented for synthesis of Yb-doped SnO 2 (Yb = 0%, 0.5%, 1.5%, 3% and 5%) NPs using a sol-gel approach. Various techniques were used to analyze the surface morphology, crystalline structure, chemical composition, and optical properties of the prepared samples. XRD, FTIR, and HRTEM confirmed nanoparticle formation. Raman, XPS, and PL spectroscopy were employed to examine electronic, optical properties, and lattice defects. Introducing Yb dopant into Yb-SnO 2 NPs enhanced their optical features, as indicated by a significant red shift. These particles exhibited impressive catalytic efficiency, degrading 98% of a 10 ppm RB dye solution within a 60-min period under UV light irradiation. Furthermore, the recyclability analysis demonstrated that the 5% Yb catalyst can be recycled multiple times. Scavenger tests were performed for the 5% Yb sample to explore primary active species involved in the degradation process. The magnetic features of the synthesized samples were investigated using VSM analysis, revealing an increase in M max from 3.98 × 10−3 to 10.40 × 10−3 emu/g. This enhancement was associated with the activation of the FCE, induced by the presence of oxygen vacancies. These findings are instrumental in propelling the advancement of sophisticated materials for both sustainable wastewater treatment and applications in spintronics. [ABSTRACT FROM AUTHOR]

• Using a sol–gel method, La-doped SnO 2 nanoparticles were successfully synthesized. • The crystallite size of the synthesized samples lies in the range of 12.78–9.63 nm. • The HRTEM determined particle size distribution within the range of 14–11 nm. • Oxygen vacancies were investigated using PL, Raman and XPS Spectroscopy. • Magnetization was shown to rise with increasing La content. • As dopant concentration increases, the band gap reduces from 3.74 eV to 3.51 eV. • 94% degradation of RB dye was achieved in 60 min under UV irradiation. Effectively eliminating dyes and heavy metals from wastewater, without secondary contamination and with easy recovery, is a significant challenge. To address this, SnO 2 -based photocatalysts were fabricated using a straightforward sol–gel method, aiming to achieve high-value reutilization and environmental protection. Utilizing XRD, FTIR, and HRTEM, the investigation has conclusively confirmed the emergence of nanoparticles (NPs) through rigorous analysis and observation techniques. Raman, XPS, and PL spectroscopy probed electronic, optical properties, and lattice defects, offering comprehensive insights into material characteristics. Specific BET surface areas were observed to be 17.72 and 39.64 m2/g for 0 % and 5 % La samples. The introduction of dopant La to the SnO 2 lattice resulted in enhanced optical properties, demonstrated by a significant red shift. La-SnO 2 nanoparticles demonstrated remarkable catalytic efficacy, degrading 94 % of RB dye solution under 60 min of UV light exposure. Even after four cycles, the catalytic degradation activity remained high at 87 %, showcasing excellent structural stability. Enhanced adsorption capacity and effective separation of electron-hole pairs under light contribute to this improvement. Moreover, the study delved into defect-based room temperature ferromagnetism (RTFM) by examining the formation of a novel network, such as La3+-O-Sn4+. The results highlight the potential of these composites doped photocatalysts as effective materials for degrading harmful organic pollutants in wastewater treatment and for their application in spintronic devices. The present study aims to characterize the structural, magnetic, and optical attributes of La-doped SnO 2 nanoparticles. [ABSTRACT FROM AUTHOR]

Anti-CDK4/6 therapy has been employed for the treatment for head and neck squamous cell carcinoma (HNSCC) with CDK4/6 hyperactivation, but the response rate is relatively low. In this study, we first showed that CDK4 and CDK6 was over-expressed and conferred poor prognosis in HNSCC. Moreover, in RB-positive HNSCC, STAT3 signaling was activated induced by CDK4/6 inhibition and STAT3 promotes RB deficiency by upregulation of MYC. Thirdly, the combination of Stattic and CDK4/6 inhibitor results in striking anti-tumor effect in vitro and in Cal27 derived animal models. Additionally, phospho-STAT3 level negatively correlates with RB expression and predicts poor prognosis in patients with HNSCC. Taken together, our findings suggest an unrecognized function of STAT3 confers to CDK4/6 inhibitors resistance and presenting a promising combination strategy for patients with HNSCC. • CDK4/6 inhibitors result in STAT3 nuclear translocation and activation. • STAT3 promotes RB deficiency by upregulation of MYC in RB-positive cells. • The small molecule inhibitor of STAT3, Stattic acts in synergy with CDK4/6 inhibitors in mouse model. • Phospho-STAT3 activity negatively correlates with RB expression in patients with HNSCC. [ABSTRACT FROM AUTHOR]

Herein we report a case of an extremely rare pancreatic adenocarcinoma with enteroblastic differentiation (AED), an underrecognized histological subtype. Moreover, the tumor was mixed with a neuroendocrine carcinoma (NEC), which is also a rare malignancy in the pancreas. The patient was an elderly male who was incidentally diagnosed with a 35 mm-sized pancreatic head tumor and underwent pancreatoduodenectomy. Histopathologically, the tumor was composed of four different types: conventional ductal adenocarcinoma, AED, NEC, and squamous cell carcinoma. Interestingly, p53 overexpression and loss of Rb expression, which are characteristic findings of NEC, were observed in all components. He had been received adjuvant chemotherapy after the surgery, however, he died of bath-related cardiac arrest 14 months after surgery. In the stomach, AED, a carcinoma resembling fetal gut epithelium, is a rare but established subtype and is considered a related entity of hepatoid carcinoma (HAC). However, gastric AED and HAC differ to some extent. In contrast to the stomach, extragastric AED, including pancreatic AED, is extremely rare, and its biological features are unclear. A mixed tumor with NEC is a complex phenomenon, but it is occasionally reported in extragastric AED. The histogenesis of mixed AED-NEC can be resolved by determining p53 and Rb status. Owing to their rare and novel nature, extragastric AED is under-recognized or confused with HAC. Further studies and the establishment of an extragastric AED classification are required. • Pancreatic adenocarcinoma with enteroblastic differentiation (AED) is extremely rare. • Clinicopathological features of extragastric AED, including pancreatic AED, are unclear. • Extragastric AED is occasionally mixed with a neuroendocrine carcinoma (NEC) component. • Combination with NEC component seems to worsen the patient prognosis. • Rb expression can be a key that reveals mixed AED-NEC histogenesis. [ABSTRACT FROM AUTHOR]

Inhibition of mammalian target of rapamycin complex 1 (mTORC1) with rapamycin in the absence of transforming growth factor-β (TGFβ) signaling induces apoptosis in many cancer cell lines. In the presence of TGFβ, rapamycin induces G1 cell cycle arrest; however, in the absence of TGFβ, cells do not arrest in G1 and progress into S-phase where rapamycin is cytotoxic rather than cytostatic. However, we observed that DU145 prostate and NCI-H2228 lung cancer cells were resistant to the cytotoxic effect of rapamycin. Of interest, the rapamycin-resistant DU145 and NCI-H2228 cells have mutations in the RB and CDKN2A tumor suppressor genes. The gene products of RB and CDKN2A (pRb and p14ARF) suppress E2F family transcription factors that promote cell cycle progression from G1 into S. Restoration of wild type RB or inhibition of E2F activity in DU145 and NCI-H2228 cells led to rapamycin sensitivity. These data provide evidence that the combination of mutant RB and mutant CDKN2A in cancer cells leads to rapamycin resistance, which has implications for precision medicine approaches to anti-cancer therapies. [ABSTRACT FROM AUTHOR]

: Neuroendocrine carcinomas (NECs) are aggressive malignant diseases. Platinum-etoposide (PE) combination is the standard first-line treatment, whatever the primary location. The NEC score and also retinoblastoma protein (Rb) status have been suggested to be predictive/prognostic factors in NEC. The primary objective of our multicentric retrospective study was to evaluate the prognostic relevance of the NEC score and Rb status, assessed by immunohistochemistry in PE-treated patients with metastatic NEC. Seven centres participated. The inclusion criteria were NEC, whatever the primary site, metastatic stage, first-line treatment with PE and tissue samples available. Rb status was determined centrally. We report multicentric data from 185 metastatic patients (37% women, median age 63). There were 108 small-cell NECs (SCNECs, 58.4%), 50 large-cell NECs (LCNECs, 27%) and 27 not otherwise specified NECs (nosNECs, 14.6%). The primary sites were the thorax (37%), gastroenteropancreatic sites (38%), unknown (15%) and other (9%). The mean Ki-67 index was 76% (range 20–100). Rb status was interpretable in 122 cases. Rb expression was lost in 74% of the cases: 84% of SCNEC vs. 60% and 63% of LCNEC and nosNEC, respectively (p = 0.016). Objective response was seen in 70% of SCNEC, 45% of LCNEC and 48% of nosNEC (p < 0.001) and in 62% of Rb-negative tumours vs. 46% of Rb-positive tumours (p = 0.3). There was no difference in median progression-free survival or overall survival (OS) as per Rb status. Age, NEC score and response to chemotherapy were the main factors associated with OS in our cohort. In our series, Rb status had no prognostic impact in PE-treated metastatic patients with NEC, whereas age, NEC score and response to chemotherapy were the main factors associated with OS • Neuroendocrine carcinomas are aggressive malignant diseases with a bad prognosis. • Rb loss of expression might be a key prognostic/predictive parameter. • Multicenter data confirm the NEC score as the only prognostic factor on OS. • Rb status had no prognostic effect on OS or progression-free survival. [ABSTRACT FROM AUTHOR]

Radiotherapy alters the tumor microenvironment and reprograms cellular metabolism. Transition of tumor cell phenotypes contributes to post-radiotherapy tumor recurrence. Low radiosensitivity of glioma stem cells is one of the reasons for radiotherapy failure. Here, we found that radiotherapy resulted in a higher proportion of infiltration of inflammatory macrophages in glioma non-stem cell grafts compared with that in glioma stem cell-transplanted tumors in a mouse model, where immunosuppressive macrophages dominated in the tumor microenvironment. In radioresistant glioma stem cells, ionizing radiation upregulated CD47 expression by AMP-activated protein kinase (AMPK), resulting in the inhibition of phagocytosis and the promotion of M2-like polarization in macrophages. Ionizing radiation promoted H3K4 methylation on CD47 promotor by downregulating KDM5A. Hyper-phosphorylated retinoblastoma protein RB maintained its dissociation status with KDM5A following AMPK activation, which inhibited the demethylated function of KDM5A. In contrast, in radiosensitive glioma non-stem cells, RB S807/S811 hypo-phosphorylation contributed to the binding of RB with KDM5A, which suppressed H3K4 methylation on CD47 promotor. In addition, ionizing radiation promoted H3K27 acetylation on CD47 promotor by HDAC7 in glioma stem cells. These data suggested that glioma stem cells reprogrammed the tumor immune microenvironment by epigenetic editing to escape macrophage phagocytosis after ionizing radiation. Targeting CD47 might be a potential strategy to sensitize glioblastoma to radiotherapy. • RB S807/S811 phosphorylation is important for the binding of RB with KDM5A in radiosensitive glioma non-stem cells. • RB maintains in a hyper-phosphorylated status in radioresistant glioma stem cells after radiation. • The dissociation of hyper-phosphorylated RB with KDM5A induces H3K4 methylation on CD47 promotor. [ABSTRACT FROM AUTHOR]

MiR-7-5p has been demonstrated to inhibit tumorigenesis by limiting tumor cell proliferation, migration and invasion. However, its role in countering hydroquinone (HQ)-induced malignant phenotype of TK6 cells has remained unclear. The present study aimed to investigate whether miR-7-5p overexpression could restrain the malignant phenotype in TK6 cells exposed to HQ. The results displayed that HQ suppressed the expression of miR-7-5p and promoted cell cycle progression. Further investigations confirmed that miR-7-5p could decelerate the cell cycle progression by targeting Rb after acute HQ exposure. Through the regulation of the Rb/E2F1 signaling pathway, the overexpression of miR-7-5p mitigated HQ-induced malignant phenotype in TK6 cells by impeding cell cycle progression. In conclusion, miR-7-5p overexpression appears to be involved in HQ-induced malignant transformation by suppressing Rb/E2F1 signaling pathway, resulting in a deceleration of the cell cycle progression. [ABSTRACT FROM AUTHOR]

TP53 , PTEN , and RB1 tumor suppressor genes (TSGs) are recurrently altered in treatment-resistant prostate cancer. Cooperative loss of two or more TSGs may drive more aggressive disease. To determine clinical outcomes of single and compound TSG alterations across the spectrum of prostate cancer. Massively parallel targeted sequencing using castration-sensitive prostate cancer (CSPC; localized [L] and metastatic [M1]) and castration-resistant prostate cancer (CRPC) specimens (n = 285). TSG altered (TSG-alt) was any copy number loss or deleterious mutation of one or more TSGs (TP53 , PTEN , and RB1). For L-CSPC, event-free survival (EFS) and time to CRPC were estimated. For M1-CSPC and M1-CRPC, overall survival (OS) was estimated. Cox regression models assessed the association between cumulative TSG hits (zero hits vs one hit vs two to three hits) and outcomes with multivariable analyses adjusted for clinicopathological factors. TSG variants increased with advanced disease (L-CSPC: 39%; M1-CSPC: 63%, M1-CRPC: 92%). TSG-alt L-CSPC had shorter EFS (median 2.6 yr, hazard ratio [HR] 1.95, 95% confidence interval [CI] 1.22–3.13) and time to CRPC (median 9.5 mo, HR 3.36, 95% CI 1.01–11.16). Cumulative gene hits led to an incremental risk of relapse (EFS: one gene, HR 1.69, 95% CI 0.99–2.87; two to three genes, HR 2.70, 95% CI 1.43–5.08; both versus zero genes, p = 0.004). There was evidence of inferior OS with increasing TSG hits in the metastatic cohorts. Only four (8%) patients in the M1-CRPC cohort were TSG-neg, one of whom died after 5.2 yr. Multivariable analyses adjusting for mutational and copy number burden did not demonstrate a significant independent association of increasing gene hits and poorer outcomes. Deleterious TSG variants are associated with an increased risk of relapse (L) and death (M1) in CSPC. Poorer outcomes are seen with compound gene hits in both early and advanced disease, and this may in part reflect increasing global genomic instability. Men with prostate tumors with compound tumor suppressor gene mutations have poorer outcomes. These findings help identify patients with aggressive features who may benefit from intensified treatment. Alterations of TP53, PTEN, and RB1 tumor suppressor genes are present across the clinical spectrum of prostate cancer and are particularly frequent in metastatic and castration-resistant disease. Alterations are associated with poorer outcomes, with incremental risk seen with compound loss, thereby identifying at-risk patient subgroups in the early and advanced disease settings. [ABSTRACT FROM AUTHOR]

Human epidermal growth factor receptor 2 (HER2) is amplified in about 20% breast cancers. Treat of HER2 positive breast cancers has been greatly promoted in last few years, but the accompany HER2 blockade has hindered the therapeutic effect. Pyrotinib is a pan-HER kinase inhibitor that suppresses signaling through the RAS/RAF/MEK/MAPK and PI3K/AKT pathways. Palbociclib is a CDK4/6 inhibitor that inhibits cell cycle progression and cancer cell proliferation in ER+ breast cancers. We hypothesized that the combination of pan-HER kinase inhibitors and CDK4/6 inhibitors would show synergistic antitumor activity in vivo in vitro. Our data show that a combination of palbociclib and pyrotinib was highly synergistic in inhibiting cancer proliferation and colony formation. The combined treatment also induced significant decreases in pAKT and pHER3 activation, induced G0-G1 cell cycle arrest, and increased rates of apoptosis. In the xenograft model, the combination treatment demonstrated greater antitumor activity than either agent alone, with no apparent increase in toxicity. Our results offer a preclinical rationale clinical investigation of the effectiveness of a combination treatment of palbociclib with pyrotinib for breast cancer treatment. [ABSTRACT FROM AUTHOR]

Abstract As a Second generation tyrosine kinase inhibitor (TKI), afatinib is approved to treat advanved/metastatic EGFR-mutant NSCLC (non-small cell lung cancer). However, the clinical application of afatinib is limited via acquired resistance. It has been revealed that CDK4/6 inhibitors hinder proliferation of cells and bring about differentiation as well as death of multiple malignant cells not only in vivo but also in vitro. Our research investigated whether a combination of Palbociclib with afatinib treatment was able to reverse acquired resistance with regard to NSCLC cells. The findings of our research demonstrated that combined Palbociclib and afatinib treatment exerted synergism in decreasing survival of cells with acquired resistance. Furthermore, combined Palbociclib with afatinib attenuated resistance that brings about recurrence of malignancies in xenografts with acquired resistance. In summary, the combination of Palbociclib and afatinib serves as an innovative strategy to reverse the acquired AR in pulmonary malignancies. [ABSTRACT FROM AUTHOR]

Abstract Vascular endothelial cell (VEC) senescence is an initiating factor in numerous cardiovascular diseases. Recent studies showed that 17β-estradiol (17β-E2), an estrogen with numerous biological activities such as inhibition of atherosclerosis, protects VECs from senescence. However, the effects of 17β-E2 on human umbilical VECs (HUVECs) remain unknown. This study investigated the anti-senescent effect of 17β-E2 on HUVECs and explored the underlying mechanism with respect to autophagy and p53 activity. First, rapamycin and 3-methyladenine were used to clarify the relationship between autophagy and senescence in HUVECs, and an inverse relationship was demonstrated. Next, the effect of 17β-E2 on H 2 O 2 -induced senescence of HUVECs was examined. Increased autophagy induced by 17β-E2 inhibited H 2 O 2 -induced senescence of HUVECs, increased cell viability, and maintained HUVEC morphology. 17β-E2 pre-treatment also decreased cell cycle arrest, decreased the dephosphorylation of Rb, decreased the production of ET-1, and increased the production of NO. Most importantly, 17β-E2 pre-treatment increased autophagy by activating p53 and its downstream effector p53-upregulated modulator of apoptosis (PUMA). Overall, our data indicate the critical role of autophagy in the anti-senescent effect of 17β-E2 on HUVECs. Highlights • Autophagy inhibits the senescence and protects the structure of HUVECs. • 17β-E2 inhibits senescence of HUVECs by promoting autophagy. • 17β-E2 functions against senescence via the regulation of p53 and PUMA. [ABSTRACT FROM AUTHOR]

Cyclin-dependent kinase 4 (CDK4) and retinoblastoma protein (RB) are both important cell-cycle regulators that function in different scenarios. Here, we report that FERM domain-containing 8 (FRMD8) inhibits CDK4 activation and stabilizes RB, thereby causing cell-cycle arrest and inhibiting colorectal cancer (CRC) cell growth. FRMD8 interacts separately with CDK7 and CDK4, and it disrupts the interaction of CDK7 with CDK4, subsequently inhibiting CDK4 activation. FRMD8 competes with MDM2 to bind RB and attenuates MDM2-mediated RB degradation. Frmd8 deficiency in mice accelerates azoxymethane/dextran-sodium-sulfate-induced colorectal adenoma formation. The FRMD8 promoter is hypermethylated, and low expression of FRMD8 predicts poor prognosis in CRC patients. Further, we identify an LKCHE-containing FRMD8 peptide that blocks MDM2 binding to RB and stabilizes RB. Combined application of the CDK4 inhibitor and FRMD8 peptide leads to marked suppression of CRC cell growth. Therefore, using an LKCHE-containing peptide to interfere with the MDM2-RB interaction may have therapeutic value in CDK4/6 inhibitor-resistant patients. [Display omitted] • FRMD8 prevents CDK7-mediated CDK4 activation and stabilizes RB • FRMD8 deficiency accelerates AOM/DSS-induced colorectal adenoma formation • Low expression of FRMD8 predicts a poor prognosis in CRC patients • The LKCHE-containing peptide inhibits cell proliferation by stabilizing RB Yu et al. report on a colorectal tumor-suppressive protein, FRMD8, which acts as a specific intrinsic inhibitor of CDK4 and an effective RB stabilizer, thereby inhibiting cell-cycle progression and CRC cell proliferation. The LKCHE-containing peptide may be of therapeutic value. [ABSTRACT FROM AUTHOR]

Overexpression and/or hyperactivation of cyclin-dependent kinase 4 (CDK4) has been found in many types of human cancers, and a CDK4 specific inhibitor, palbociclib, has been recently approved by the FDA for the treatment of breast cancer. However, the expression and the therapeutic potential of CDK4 in osteosarcoma remain unclear. In the present study, CDK4 was found to be highly expressed in human osteosarcoma tissues and cell lines as compared with normal human osteoblasts. Elevated CDK4 expression correlated with metastasis potential and poor prognosis in osteosarcoma patients as determined by immunohistochemical analysis in a human osteosarcoma tissue microarray (TMA). CDK4 inhibition by either palbociclib or specific small interference RNA (siRNA) exhibited dose-dependent inhibition of osteosarcoma cell proliferation and growth, accompanied by suppression of the CDK4/6-cyclinD-Rb signaling pathway. Flow cytometry analysis showed that CDK4 knockdown arrested osteosarcoma cells in the G1 phase of the cell cycle and induced cell apoptosis. Furthermore, inhibition of CDK4 significantly decreased osteosarcoma cell migration in vitro determined by the wound healing assay. These data highlight that CDK4 may be a potential promising therapeutic target in the treatment of human osteosarcoma. [ABSTRACT FROM AUTHOR]

Adipogenesis comprises the signaling program of cell differentiation by which preadipocytes become adipocytes and is a key process that is required in adipocyte hypertrophy in the development of obesity. In this study, we investigated the effect of 11,13 dihydro-[11 R ]-dehydroleucodine (i.e., leucodine), a sesquiterpene lactone obtained from the reduction of dehydroleucodine, on adipogenesis of 3T3-L1 preadipocyte. 11,13 dihydro-[11 R ]-dehydroleucodine blocked the accumulation of lipid droplets stained with Oil Red O and inhibited the increase of triglycerides in the adipocytes (IC 50 : 71.0 ± 4.1 μM). Expressions of Glut-4, adiponectin and perilipin-2 were blocked in the presence of 11,13 dihydro-[11 R ]-dehydroleucodine. Furthermore, expression of PPARγ and C/EBPα was significantly inhibited by 11,13 dihydro-[11 R ]-dehydroleucodine as well as the expression of C/EBPβ was also strongly inhibited in time- and concentration-dependent manner. This is consistent with the inhibitory effect of 11,13 dihydro-[11 R ]-dehydroleucodine on the early stage of adipogenesis. Thus, the proliferation of preadipocytes were also suppressed by addition of 11,13 dihydro-[11 R ]-dehydroleucodine during the first 48 h after induction. These results indicate that 11,13 dihydro-[11 R ]-dehydroleucodine may selectively affect mitotic clonal expansion to block preadipocyte differentiation. 11,13 dihydro-[11 R ]-dehydroleucodine stopped the cell cycle at the G 0 /G 1 phase by diminishing the increase of phosphorylation of Rb, Erk1/2 and Akt while increasing the expression of p27. Collectively, our results indicate that the inhibition of early stage preadipocytes differentiation by 11,13 dihydro-[11 R ]-dehydroleucodine may be associated with cell cycle arrest at the G 0 /G 1 phase through upregulation of p27 expression. [ABSTRACT FROM AUTHOR]

Sarcomas are rare and complex malignancies that have been associated with a poor prognostic outcome. Over the last few decades, traditional treatment with surgery and/or chemotherapy has not significantly improved outcomes for most types of sarcomas. In recent years, there have been significant advances in the understanding of specific gene mutations that are important in driving the pathogenesis and progression of sarcomas. Identification of these new gene mutations, using next-generation sequencing and advanced molecular techniques, has revealed a range of potential therapeutic targets. This, in turn, may lead to the development of novel agents targeted to different sarcoma subtypes. In this review, we highlight the advances made in identifying sarcoma gene mutations, including those of p53, RB, PI3K and IDH genes, as well as novel therapeutic strategies aimed at utilizing these mutant genes. In addition, we discuss a number of preclinical studies and ongoing early clinical trials in sarcoma targeting therapies, as well as gene editing technology, which may provide a better choice for sarcoma patient management. [ABSTRACT FROM AUTHOR]

Tris (2-chloroethyl) phosphate (TCEP) has been widely used as a plasticizer and flame retardant. TCEP as a potential carcinogen is often detected in the occupational and nature environments. To investigate effects of TCEP on human hepatocytes, we assessed cell growth rate, cellular membrane integrity, senescence-associated β-galactosidase (SA-β-Gal) activity and analyzed expression of regulators involved in the p53-p21 Waf1/Cip1 -Rb pathway in TCEP-treated L02 cells. The results showed TCEP increased the percentage of SA-β-Gal positive cells, decreased IL-6 levels, down-regulated the regulators of p38MAPK-NF-κB pathways, but up-regulated the regulators of p21 Waf1/Cip1 -Rb pathway in L02 cells. Furthermore, we measured the SA-β-Gal activity and expression of regulators involved in the p53-p21 Waf1/Cip1 -Rb pathway in L02 −p53 cells and p53-null Hep3B cells. Similar results were found in L02 −p53 cells and Hep3B cells. The findings demonstrated that TCEP induced senescence-like growth arrest via the p21 Waf1/Cip1 -Rb pathway in a p53-independent manner, without activation of the IL-6/IL6R, p38MAPK-NF-κB pathways in hepatocytes. [ABSTRACT FROM AUTHOR]

Dune fields of Quaternary age occupy large areas of the world's arid and semiarid regions. Despite this, there has been surprisingly little work done on understanding dune sediment provenance, in part because many techniques are time-consuming, prone to operator error, experimental, highly specialized, expensive, or require sophisticated instrumentation. Provenance of dune sand using K/Rb and K/Ba values in K-feldspar in aeolian sands of the arid and semiarid regions of North America is tested here. Results indicate that K/Rb and K/Ba can distinguish different river sands that are sediment sources for dunes and dune fields themselves have distinctive K/Rb and K/Ba compositions. Over the Basin and Range and Great Plains regions of North America, the hypothesized sediment sources of dune fields are reviewed and assessed using K/Rb and K/Ba values in dune sands and in hypothesized source sediments. In some cases, the origins of dunes assessed in this manner are consistent with previous studies and in others, dune fields are found to have a more complex origin than previously thought. Use of K/Rb and K/Ba for provenance studies is a robust method that is inexpensive, rapid, and highly reproducible. It exploits one of the most common minerals found in dune sand, K-feldspar. The method avoids the problem of using simple concentrations of key elements that may be subject to interpretative bias due to changes in mineralogical maturity of Quaternary dune fields that occur over time. [ABSTRACT FROM AUTHOR]

Branching fractions for product channels of the reactions of Rb(6 2 P) with H 2 , CH 4 and C 2 H 6 involving energy transfer and chemical transformation have been measured using time-resolved pulsed laser techniques. Removal of Rb(6 2 P) atoms was monitored using laser induced fluorescence (LIF) measurements. The RbH product was detected using LIF of the A-X transition in the 500–530 nm spectral range. Pump-probe measurements indicated a collisional loss of rubidium atoms due to the reactions of Rb(6 2 P) with H 2 and C 2 H 6 with branching fractions γ H 2 c h =0.21±0.03 and γ C 2 H 6 c h =0.10±0.03, respectively. The measurements for Rb(6 2 P) + CH 4 did not provide conclusive evidence for a reactive loss channel. We detected RbH (v=0, 1 and 2) produced from Rb(6 2 P) in the presence of H 2 . Surprisingly, the RbH product was not detected with CH 4 or C 2 H 6 , despite the fact that high-level ab initio calculations show the existence of favorable pathways for RbH formation. The branching fractions for the energy transfer product channels were found to be γ H 2 r e l =0.79±0.05, γ C 2 H 6 r e l =0.92±0.05 and γ C H 4 r e l =0.98±0.05 for H 2 , CH 4 and C 2 H 6 , respectively. The undetectable loss of Rb via the reaction with methane suggests that CH 4 may be the more stable diluting agent for use in the diode pumped Rb vapor laser system. [ABSTRACT FROM AUTHOR]

Summary RNAi has enabled researchers to study the function of many genes. However, it is not understood why some RNAi experiments succeed while others do not. Here, we show in C. elegans that pharyngeal muscle is resistant to RNAi when initially exposed to double-stranded RNA (dsRNA) by feeding but sensitive to RNAi in the next generation. Investigating this observation, we find that pharyngeal muscle cells as well as vulval muscle cells require nuclear rather than cytoplasmic RNAi. Further, we find in these cell types that nuclear RNAi silencing is most efficiently triggered during early development, defining a critical period for initiating nuclear RNAi. Finally, using heat-shock-induced dsRNA expression, we show that synMuv B class mutants act in part to extend this critical window. The synMuv-B-dependent early-development-associated critical period for initiating nuclear RNAi suggests that mechanisms that restrict developmental plasticity may also restrict the initiation of nuclear RNAi. [ABSTRACT FROM AUTHOR]

Plakophilin 3 (PKP3) is a component of desmosomes and is frequently overexpressed in cancer. Using keratinocytes either lacking or overexpressing PKP3, we identify a signaling axis from ERK to the retinoblastoma (RB) protein and the E2F1 transcription factor that is controlled by PKP3. RB and E2F1 are key components controlling G1/S transition in the cell cycle. We show that PKP3 stimulates the activity of ERK and its target RSK1. This inhibits expression of the transcription factor RUNX3, a positive regulator of the CDK inhibitor CDKN1A/p21, which is also downregulated by PKP3. Elevated CDKN1A prevents RB phosphorylation and E2F1 target gene expression, leading to delayed S phase entry and reduced proliferation in PKP3-depleted cells. Elevated PKP3 expression not only increases ERK activity but also captures phosphorylated RB (phospho-RB) in the cytoplasm to promote E2F1 activity and cell-cycle progression. These data identify a mechanism by which PKP3 promotes proliferation and acts as an oncogene. [Display omitted] • PKP3-expressing cells reveal higher proliferation rates • PKP3 captures hyper-phosphorylated RB in the cytoplasm • This increases E2F activity and promotes G1/S phase transition • Upstream of RB, PKP3 increases mitogenic signaling via ERK and RSK Müller et al. elucidate plakophilin 3's (PKP3) functions in proliferation. (1) PKP3 serves as a scaffold for ERK and RSK to enhance mitogenic signaling. (2) PKP3 directly promotes cell-cycle progression by capturing and inactivating the tumor-suppressor protein RB. This provides insights into PKP3's role in cancer. [ABSTRACT FROM AUTHOR]

PRDM1 (PR domain containing 1) is a transcriptional repressor that affects the expression of numerous genes involved in cell proliferation, differentiation and metabolism. However, the molecular mechanisms underlying PRDM1-regulated gene expression in the DF-1 cell line remain to be elucidated. In this study, we explored the role of PRDM1 in cell proliferation and cell cycle by forced expression of PRDM1 in DF-1 cells. Our results showed an absence of endogenous PRDM1 in this cell line, while exogenous PRDM1 was specifically localized to the nucleus. Ectopic expression of PRDM1 inhibited DF-1 cell proliferation and altered clonal morphology. Furthermore, PRDM1 overexpression caused an increase in the G0/G1 phase population. The levels of p53 mRNA and the p53-regulated p21 WAF1 and MDM2 genes were significantly increased in DF-1 cells transfected with the PRDM1 expression vector. Examination of the Rb pathway further revealed that Rb, E2F-1 and p15 INK4b alternate reading frame (ARF) mRNA were also significantly increased after transient transfection. Interestingly, the mRNA expression levels of multiple chicken cyclin genes were also increased. These results show that PRDM1 overexpression induced G0/G1 arrest in DF-1 cells through multiple parallel mechanisms, including the p53 and Rb pathways. [ABSTRACT FROM AUTHOR]

Summary Although well characterized as a transcriptional activator that drives prostate cancer (PCa) growth, androgen receptor (AR) can function as a transcriptional repressor, and high-level androgens can suppress PCa proliferation. The molecular basis for this repression activity remains to be determined. Genes required for DNA replication are highly enriched among androgen-repressed genes, and AR is recruited to the majority of these genes, where it rapidly represses their transcription. This activity is enhanced in PCa cells expressing high AR levels and is mediated by recruitment of hypophosphorylated retinoblastoma protein (Rb). Significantly, AR also indirectly increases the expression of DNA replication genes through stimulatory effects on other metabolic genes with subsequent CDK activation and Rb hyperphosphorylation. In castration-resistant PCa cells, which are dependent on high-level AR expression, this anti-proliferative repression function might be exploited through treatment with androgen in combination with agents that suppress AR-driven metabolic functions or cell cycle progression. [ABSTRACT FROM AUTHOR]

Aiming at the problems of the low grade of rubidium (Rb) in biotite, and long leaching time and low leaching efficiency of Rb in mica ore, the chlorination roasting-assisted ultrasonic enhanced water leaching method was employed to extract Rb from biotite ore in this study. During the chlorination roasting process, the optimal conditions were obtained, namely roasting temperature 900 °C, roasting time 40 min, and the mass ratio of ore to calcium chloride 1:1, the optimum leaching rate was 96.75 %. Compared with conventional leaching, the ultrasonic field could greatly shorten the leaching time and realize fast and efficient leaching of Rb. The optimal conditions for ultrasonic enhanced leaching were: ultrasonic power 100 W, leaching temperature 60 °C, leaching time 20 min, liquid–solid ratio 4:1, the Rb leaching rate was 98.73 %, which was 40 min shorter than conventional leaching. The particle size and SEM results indicated that the samples by ultrasonic leaching were smaller, no agglomeration phenomenon in a large area, and the surface of the samples was relatively smooth. [ABSTRACT FROM AUTHOR]

A set partition σ of [ n ] = { 1 , … , n } contains another set partition π if restricting σ to some S ⊆ [ n ] and then standardizing the result gives π . Otherwise we say σ avoids π . For all sets of patterns consisting of partitions of [3], the sizes of the avoidance classes were determined by Sagan and by Goyt. Set partitions are in bijection with restricted growth functions (RGFs) for which Wachs and White defined four fundamental statistics. We consider the distributions of these statistics over various avoidance classes, thus obtaining multivariate analogues of the previously cited cardinality results. This is the first in-depth study of such distributions. We end with a list of open problems. [ABSTRACT FROM AUTHOR]

There have been no reports thus far on the structure or molecular characterization of the retinoblastoma ( Rb ) gene of aquatic animals. Herein we describe the identification of the Rb gene of the intertidal copepod Tigriopus japonicus . In silico analyses revealed the conserved Rb domains of T. japonicus with those of protostomes. Phylogenetic analysis revealed that orthologs of Rb gene were evolved by an ancient split event in deuterostomes, while only a single Rb gene was conserved in protostomes except for Drosophila . The transcription of the T. japonicus Rb gene continuously increased across the molting transition from nauplius to the copepodid and adult stages, suggesting that it may play a developmental role in the molting process of T. japonicus . Information on Rb 's response to environmental stressors, including toxin exposure, is lacking in copepods. To examine the transcriptional response to stressful conditions in laboratory culture conditions, copepods were exposed to UV-B radiation and different concentrations of metals, environmental toxins, and biocides. Transcription of the T. japonicus Rb gene was upregulated in response to about half of the 96 h-LD 50 of UV-B radiation (12 kJ/m 2 ) for 48 h, while the approximate 96 h-LD 50 value (24 kJ/m 2 ) of UV-B and relatively high concentrations of several toxins and biocides induced the downregulation of T. japonicus Rb mRNA expression. Taken together, our findings suggest that the T. japonicus Rb gene is sensitive to environmentally unfavorable conditions that can induce cell cycle alteration. [ABSTRACT FROM AUTHOR]

The retinoblastoma tumor suppressor (RB) and its related family members p107 and p130 regulate cell proliferation through the transcriptional repression of genes involved in cellular G1 to S phase transition. However, RB proteins are functionally versatile, and numerous genetic and biochemical studies point to expansive roles in cellular growth control, pluripotency, and apoptotic response. For the vast majority of genes, RB family members target the E2F family of transcriptional activators as an integral component of its gene regulatory mechanism. These interactions are regulated via reversible phosphorylation by Cyclin/Cyclin-dependent kinase (Cdk) complexes, a major molecular mechanism that regulates transcriptional output of RB/E2F target genes. Recent studies indicate an additional level of regulation involving the ubiquitin–proteasome system that renders pervasive control over each component of the RB pathway. Disruption of the genetic circuitry for proteasome-mediated targeting of the RB pathway has serious consequences on development and cellular transformation, and is associated with several forms of human cancer. In this review, we discuss the role of the ubiquitin–proteasome system in proteolytic control of RB–E2F pathway components, and recent data that points to surprising non-proteolytic roles for the ubiquitin–proteasome system in novel transcriptional regulatory mechanisms. [ABSTRACT FROM AUTHOR]

Spindle cell lipoma (SCL) is a rare tumor of soft tissues, and was first described in 1975 by Enzinger and Harvey SCL often occurs in elderly men as a solitary lesion in the posterior neck and back, and less commonly in the oral cavity. SCL of the tongue is relatively uncommon, and only 14 cases have been reported to date. Here, we describe two cases of SCL of the tongue. A 78-year-old male and a 77-year-old female were diagnosed with tongue tumors, and both underwent resection. Histopathological examination of the resected tumors revealed that they consisted of masses of mature fat cells with fibrous bundles accompanied by hyperplasia of spindle cells surrounding the adipose cells. Immunohistochemistry was performed for histological diagnosis. Using immunohistochemical staining, the spindle cells of each tumor were found to be positive for CD34 but negative for S-100. The nuclei of the spindle cells were negative for Rb and STAT6, and CDK4 and MDM2 immunostaining was negative in every tumor cell. In case 2, some spindle cells were positive for p16, but all were completely negative in case 1. Finally, these tumors were diagnosed as SCLs. To make a definitive pathological diagnosis for SCL, a panel of immunohistochemical markers incorporating CD34, S-100, STAT6, Rb, p16, MDM2 and CDK4 is required to avoid confusion with histologic mimics. [ABSTRACT FROM AUTHOR]

The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of G1 cell cycle progression. Two key substrates of mTORC1 are ribosomal subunit S6 kinase (S6K) and eukaryotic initiation factor 4E (eIF4E) binding protein-1 (4E-BP1). We reported previously that simultaneous knockdown of S6K and eIF4E causes a transforming growth factor-β (TGF-β)-dependent G1 cell cycle arrest in MDA-MB-231 human breast cancer cells. Rapamycin inhibits the phosphorylation of S6K at nano-molar concentrations in MDA-MB-231 cells; however, micro-molar concentrations of rapamycin are required to inhibit phosphorylation of 4E-BP1 – the phosphorylation of which liberates eIF4E to initiate translation. Micro-molar doses of rapamycin are required for complete G1 cell cycle arrest – indicating that 4E-BP1 is a critical target of mTOR for promoting cell cycle progression. Data are provided demonstrating that G1 cell cycle arrest induced by rapamycin is due to up-regulation of TGF-β signaling and down-regulation of Rb phosphorylation via phosphorylation of the mTORC1 substrates S6K and 4E-BP1 respectively. These findings enhance the current understanding of the cytostatic effects of mTORC1 suppression with therapeutic implications. [ABSTRACT FROM AUTHOR]

In this paper, carbon nanofibers (CNFs) were successfully synthesized by electrospinning technique. Next, Au nanoparticles (NPs) were assembled on the electrospun CNFs through in situ reduction method. By using the obtained Au NPs modified CNFs (CNFs/Au) as hard template, the In 2 S 3 /CNFs/Au composites were synthesized through hydrothermal technique. The results showed that the super long one-dimensional (1D) CNFs (about 306 nm in average diameter) were well connected to form a nanofibrous network; and, the Au NPs with 18 nm in average diameter and In 2 S 3 nanosheets with 5–10 nm in thickness were uniformly grown onto the surface of CNFs. Photocatalytic studies revealed that the In 2 S 3 /CNFs/Au composites exhibited highest visible-light photocatalytic activities for the degradation of Rhodamine B (RB) compared with pure In 2 S 3 and In 2 S 3 /CNFs. The enhanced photocatalytic activity might arise from the high separation efficiency of photogenerated electron–hole pairs based on the positive synergetic effect between In 2 S 3 , CNFs and Au components in this ternary photocatalytic system. Meanwhile, the In 2 S 3 /CNFs/Au composites with hierarchical structure possess a strong adsorption ability towards organic dyes, which also contributed to the enhancement of photocatalytic activity. Moreover, the In 2 S 3 /CNFs/Au composites could be recycled easily by sedimentation due to their nanofibrous network structure. [ABSTRACT FROM AUTHOR]

Sorafenib is the treatment of reference for advanced hepatocellular carcinoma (HCC), the most frequent form of primary liver tumour. The loss of function of the retinoblastoma (Rb) protein is an important event during liver carcinogenesis, but it is unclear whether the Rb status modulates the response of HCC cells to sorafenib. Here, we examined this question in HCC cells with reduced levels of Rb achieved through stable RNA interference. We show that HCC cells with reduced levels of Rb exhibit a two- to threefold increase in cell death induction upon exposure to sorafenib compared with controls. Sorafenib treatment of Balb/c nude mice that received tumour xenografts derived from HCC cells with reduced Rb levels resulted in complete tumour regression in 50% of the animals treated, compared with tumour stabilization in mice that received control cells. We show that, upon exposure to sorafenib, the Rb-negative status of HCC cells promotes the occurrence of ferroptosis, a form of oxidative necrosis. The findings highlight the role of Rb in the response of HCC cells to sorafenib and the regulation of ferroptosis. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) is a causative agent of chronic hepatitis. Although the standard therapy for HCV-infected patients consists of pegylated interferon plus ribavirin, this treatment is associated with serious side effects and high costs, and fails in some patients infected with specific HCV genotypes. To address this problem, we are developing small-molecule inhibitors of cyclin-dependent kinases (CDKs) as novel anti-HCV drug candidates. Previous data showed that HCV replication is inhibited by retinoblastoma protein, which is itself inactivated by CDK-mediated phosphorylation. Here, we report that CDK inhibitors suppress HCV replication in vitro and in vivo, and that CDK4 is required for efficient HCV replication. These findings shed light on the development of novel anti-HCV drugs that target host factors. [ABSTRACT FROM AUTHOR]

Highlights: [•] Genetic mutations found in familial pituitary adenomas are very rare in sporadic tumors. [•] Multiple tumor suppressive genes are inactivated in sporadic tumors by epigenetic mutations. [•] We discuss the current status of twenty genes which are lost or down regulated in sporadic pituitary tumors. [•] These genes are functionally connected to tumor suppressors RB and p53. [ABSTRACT FROM AUTHOR]

Breast phyllodes tumors are fibroepithelial neoplasms with variable risk of aggressive local recurrence and distant metastasis, and the molecular pathogenesis is unclear. Here, we systematically study p16 and Rb expression in 34 phyllodes tumors in relation to proliferation. Tissue microarrays were constructed from 10 benign, 10 borderline, and 14 malignant phyllodes (5 cores/tumor) and from 10 fibroadenomas (2 cores/tumor). Tissue microarrays were labeled by immunohistochemistry for p16, Rb, and Ki-67 and by in situ hybridization for high-risk human papillomavirus. Cytoplasmic and nuclear p16 were scored by percentage labeling (0%-100%, diffuse N95%) and intensity. Nuclear Rb was scored by percentage labeling (0%-100%, diffuse N75%) and intensity. p16 and Rb labeling were repeated on whole sections of cases with Rb loss on the tissue microarray. Twenty-nine percent (4/14) malignant phyllodes showed diffuse strong p16 labeling with Rb loss in malignant cells (diffuse p16+/Rb-), whereas 21% (3/14) malignant phyllodes showed the reverse pattern of p16 loss with diffuse strong Rb (p16-/diffuse Rb+). Results were consistent between tissue microarrays and whole sections. No borderline phyllodes, benign phyllodes, or fibroadenoma showed diffuse p16+/Rb- or p16-/diffuse Rb+ phenotypes. No cases contained high-risk human papillomavirus. Average Ki-67 proliferation indices were 15% in malignant phyllodes, 1.7% in borderline phyllodes, 0.5% in benign phyllodes, and 0% in fibroadenoma. Ki-67 was highest in malignant phyllodes with diffuse p16+/Rb- labeling. In summary, 50% malignant phyllodes display evidence of Rb/p16 pathway alterations, likely reflecting p16 or Rb inactivation. These and other mechanisms may contribute to the increased proliferation in malignant phyllodes relative to other fibroepithelial neoplasms. [ABSTRACT FROM AUTHOR]

Abstract: The Rb tumor suppressor gene performs a critical role in controlling cell proliferation and tumorigenesis; it recruits HDAC1 protein into the E2F complexes to repress transcription. In this study, we demonstrate that SNIP1, RB and HDAC1 were significantly expressed in same lung cancer tissues in a tissue microarray (TMA) containing 300 non-small cell lung cancers (NSCLC). High expression level of SNIP1 in tumor patients was significantly correlated with poor prognosis in NSCLC (log-rank P for OS=0.01, log-rank P for DFS=0.001). Functionally, SNIP1 competes with HDAC1 for binding to RB and reduces HDAC activity in vitro. Knockdown of SNIP1 reduced colony formation ability of lung cancer cells. These findings may indicate the involvement of SNIP1 in progression of lung cancer by regulating the RB/HDAC1 interaction. [Copyright &y& Elsevier]

Progression through G1/S phase of the cell cycle is coordinated by cyclin-dependent kinase (CDK) activities. Here, we find that the requirement for different CDK activities and cyclins in driving cancer cell cycles is highly heterogeneous. The differential gene requirements associate with tumor origin and genetic alterations. We define multiple mechanisms for G1/S progression in RB-proficient models, which are CDK4/6 independent and elicit resistance to FDA-approved inhibitors. Conversely, RB-deficient models are intrinsically CDK4/6 independent, but exhibit differential requirements for cyclin E. These dependencies for CDK and cyclins associate with gene expression programs that denote intrinsically different cell-cycle states. Mining therapeutic sensitivities shows that there are reciprocal vulnerabilities associated with RB1 or CCND1 expression versus CCNE1 or CDKN2A. Together, these findings illustrate the complex nature of cancer cell cycles and the relevance for precision therapeutic intervention. [Display omitted] • There is significant heterogeneity in the requirement for G1/S-promoting CDK/cyclins • Reciprocal expression relationships denote divergent cell-cycle states in tumors • Specific vulnerabilities are associated with different cell-cycle utilization • Multiple separable mechanisms drive cell-cycle progression in tumor cells Knudsen et al. find that there is extensive heterogeneity in the requirement for CDK and cyclins across cancer models. Multiple biochemically distinct mechanisms drive cell division. Divergent cell-cycle states harbor distinct genetic and pharmacological vulnerabilities, suggesting that cell-cycle diversity could be exploited for a precision approach to cancer therapy. [ABSTRACT FROM AUTHOR]

Alkali metals have been widely studied to improve the efficiency of CO 2 hydrogenation to light olefins on iron-based catalysts. Herein, a series of Rb-promoted Fe 3 O 4 microsphere catalysts were developed to understand the effects of Rb promoter on the catalytic performance. The 3wt%Rb/Fe 3 O 4 catalyst showed high selectivity of light olefins (C 2 –C 4 , 47.4%) with a high olefin/paraffin ratio (10.7). XRD, H 2 -TPR, CO 2 -TPD, XPS analyses show that the proper Rb loading rate may adjust carbonaceous species content and ferric oxide content on the surface of the catalyst which is help for the synergistic effect to produce light olefins. [Display omitted] • Rb-promoted Fe 3 O 4 microsphere catalysts were developed for CO 2 hydrogenation. • 3wt%Rb/Fe 3 O 4 catalyst showed excellent catalytic activity with high selectivity of C 2 –C 4 olefins. • Rb adjusts surface carbonaceous species content and ferric oxide content. • The ratio of Fe3+/Fe2+ and θ- Fe 3 C/χ-Fe 5 C 2 synergically effect on the Rb/Fe 3 O 4 catalyst. [ABSTRACT FROM AUTHOR]

Abstract: The reported prevalence for presence of human papillomavirus (HPV) genome in lung cancer varies across the world, and limited data are available for North America. P16 immunostaining is used as a surrogate marker for the presence of HPV in cervical and head and neck cancers. In non-small cell lung carcinoma (NSCLC), the association between P16 protein overexpression and HPV remains unclear. We investigated the presence of HPV genome by in situ hybridization (ISH) and polymerase chain reaction (PCR) and P16 or Rb protein expression by immunohistochemistry (IHC) in 336 surgically resected primary NSCLC: 204 adenocarcinoma (AdC) and 132 squamous cell carcinoma (SqCC). HPV genome was detected in 5 (1.5%) of 336 tumors studied by both ISH and PCR; all of them were typed as HPV16 and found in SqCC (3.8%). Despite being solitary tumors and clinically considered as primary lung cancers, all 5 patients had past history of HPV associated squamous cell carcinomas of other organ sites, thus highly suggestive of being metastases. P16 immunostaining was found in 137 (40.8%) tumors, with 109 (32.4%) showing high level expression. All HPV positive (+) cases showed P16 high expression. P16 and Rb protein expressions were inversely correlated (P <0.001), suggesting that the high P16 expression is largely driven by non-HPV loss of Rb protein expression. We conclude that HPV is not or rarely associated with NSCLC in Canadian and most likely North American patients, and P16 immunostaining is not a surrogate marker for its presence. [Copyright &y& Elsevier]

Abstract: A novel indirubin derivative, 5′-nitro-indirubinoxime (5′-NIO), exhibits a strong anti-cancer activity against human cancer cells. Here, the 5′-NIO-mediated G1 cell cycle arrest in lung cancer cells was associated with a decrease in protein levels of polo-like kinase 1 (Plk1) and peptidyl-prolyl cis/trans isomerase Pin1. Treatment with Plk1 siRNA or Pin1 inhibitor effectively inhibited the Rb phosphorylation, suggesting their regulatory role at G1 phase. In addition, the overexpression of Plk1 or Pin1 inhibited apoptotic signals following the cleavage of PARP in 5′-NIO-treated cells. These findings suggest that 5′-NIO have potential anti-cancer efficacy through the inhibition of Plk1 or/and Pin1 expression. [Copyright &y& Elsevier]

Abstract: Tumor suppressor genes regulate diverse cellular activities including DNA damage repair, cell cycle arrest, mitogenic signaling, cell differentiation, migration, and programmed cell death. In this review the tumor suppressor genes p53, FoxO, retinoblastoma (RB), p21, p16, and breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2) and their roles in oxidative stress are summarized with a focus on the links and interplay between their pathways and reactive oxygen species (ROS). The results of a number of studies have demonstrated an antioxidant role for tumor suppressor proteins, activating the expression of some well-known antioxidant genes in response to oxidative stress. On the other hand, recent studies have revealed a pro-oxidant role for p53 by which cellular ROS are increased by enhanced transcription of proapoptotic genes. A tightly regulated feedback loop between ROS and FoxO proteins, with ROS regulating FoxO activity through posttranslational modifications and protein interactions and FoxO controlling intracellular ROS levels, has been demonstrated. Furthermore, these studies have shown that FoxO transcription factors and p38 mitogen-activated protein kinases may interact with the RB pathway under stress conditions. In addition, cellular senescence studies established an unexpected role for ROS in inducing and maintaining senescence-induced tumor suppression that blocks cytokinesis to ensure senescent cells never divide again. p21 and p16 have been shown to act as tumor suppressor proteins and this function extends beyond cell cycle control and includes important roles in regulating oxidative stress. Consequently, these important interactions indicate a critical potential role for tumor suppressor genes in the cellular response against oxidative stress and emphasize links between ROS and tumor suppressor genes that might be therapeutic targets in oxidative damage-associated diseases. [Copyright &y& Elsevier]

Summary: Gastrointestinal stromal tumors feature a wide spectrum of biologic behavior, ranging from benign to extremely malignant. To determine the role of p16INK4a alteration in progression of gastrointestinal stromal tumors of the stomach, we have investigated protein expression and gene methylation in correlation with clinicopathologic factors and survival. In addition to immunohistochemical analysis of p16INK4a in a series of 95 cases, real-time quantitative methylation specific polymerase chain reaction for p16INK4a and immunostaining for cyclin D1, cyclin E, pRb, DP-1, E2F-1, and Ki-67 were also evaluated in randomly selected samples. The p16INK4a labeling indices ranged from 0% to 74% (median, 21%), demonstrating a significant inverse correlation with size (P = .046). On univariate (P = .003) and multivariate (P = .067) analyses, loss of p16INK4a expression increased the likelihood of a poor tumor-related survival. In addition, size (P = .036) and the mitotic index (P = .005) had independent prognostic influence. The p16INK4a methylation index, which ranged from 0% to 100% (median, 17%), was significantly higher in larger tumors (P < .001) and in high-risk category lesions (P = .001) and inversely correlated with protein expression. Hierarchical cluster analysis based on expression of p16INK4a network members identified 2 clusters in 27 randomly selected tumor samples, containing 11 and 16 tumors each. Former cluster samples demonstrated higher risk category (P = .022), higher p16INK4a methylation (P < .001), and more reduced pRb expression (P < .018). In addition, p16INK4a network members clustered into 2 groups: (1) showing down-regulated p16INK4a protein and up-regulating of both cyclin D1 and DP-1 and (2) down-regulated pRb and up-regulated E2F-1. We conclude that p16INK4a alteration has an important role in progression of gastrointestinal stromal tumors of the stomach. Furthermore, the study provides a possible link between regulation of p16INK4a network members and gastrointestinal stromal tumors. [Copyright &y& Elsevier]

Abstract: Prostate cancer (PCa) continues to be one of the leading causes of cancer-related deaths among American men. The prostate relies upon the androgen receptor (AR) to mediate the effects of androgens on normal growth, a reliance that is maintained during malignant prostate growth. Caveolin-1 (Cav-1), the main structural component of caveolae, has been shown to promote the malignant growth and invasion of prostate tumors. In vitro work has shown that Cav-1 can act as an AR coactivator by enhancing its transciptional activity. However, it is unknown how Cav-1 affects androgen-dependent growth and signaling in vivo. To explore this role, a novel mouse model of Cav-1 overexpression was developed with a hormone-insensitive promoter. Cav-1 transgenic (Tg) mice subjected to castration and androgen stimulation display enlarged prostate weights and increased DNA synthesis. Through gene transcript and proteomic profiling, we demonstrate that Cav-1 overexpression favors androgen-regulated responses and enhances processes involved in transcription, cell cycle progression and protein synthesis. Interestingly, Cav-1 overexpression was associated with an increase in the phosphorylation of AR on serine 210, a post-translational modification linked to its activity under androgen-stimulated conditions. In addition, these mice exhibited an increase in the phosphorylation of ribosomal S6 protein on serine 235/236 (pS6), a marker of protein synthesis and a downstream component of the mTOR pathway. Thus, Cav-1 Tg mice could serve as a novel model for studying AR-regulated pathways involved in prostate growth and proliferation. [Copyright &y& Elsevier]

Abstract: An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium (133Cs and 137Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and 133Cs mass concentrations with 137Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg−1 for K (mean ± SD, dwt), 0.40 ± 0.09 g kg−1 for Rb, 8.7 ± 4.36 mg kg−1 for 133Cs and 63.7 ± 24.2 kBq kg−1 for 137Cs. The mass concentrations of 133Cs correlated with 137Cs activity concentrations (r = 0.61). There was correlation between both 133Cs concentrations (r = 0.75) and 137Cs activity concentrations (r = 0.44) and Rb, but the 137Cs/133Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The 133Cs mass concentrations, 137Cs activity concentrations and 137Cs/133Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, 133Cs and 137Cs in sporocarps of S. variegatus is similar to other fungal species. [Copyright &y& Elsevier]

Abstract: Aberrant oncogenic signals are typically counteracted by anti-proliferative mechanisms governed principally by the p53 and Rb tumour-suppressor proteins. Apoptosis is firmly established as a potent anti-proliferative mechanism to prevent tumour growth but it is only in recent years that oncogene-induced senescence has achieved similar recognition. Senescence is defined as an irreversible cell-cycle arrest suggesting that entry of oncogene-expressing cells into this static yet viable state is permanent. However, tumours do develop and express the very same oncogenes that landed them in jail. We ask whether this is because rogue incipient cancer cells find ways to escape this imposed imprisonment or otherwise entirely avoid capture by senescence gate-keepers. [ABSTRACT FROM AUTHOR]

Abstract: Apoptosis is induced by the cleavage of a subset of cellular proteins by proteases of the caspase family. Numerous (hundreds) caspase substrates have been described but only for a few of them is the function of their cleavage by caspases well understood. In this review, apoptosis and caspases will first be introduced. The main focus will then be directed to the caspase substrates, the actual “workers” doing the job of mediating and regulating the apoptotic process. The caspase substrates whose functions upon cleavage have been carefully investigated and those that are potentially involved in neurodegenerative diseases will be discussed in detail. [Copyright &y& Elsevier]

Abstract: The aryl hydrocarbon receptor (AHR) mediates the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. In some mammalian cell lines, TCDD induces G1 cell cycle arrest, which depends on an interaction between the AHR and the retinoblastoma tumor suppressor (RB). Mammals possess one AHR, whereas fishes possess two or more AHR paralogs that differ in the domains important for AHR–RB interactions in mammals. To test the hypothesis that fish AHR paralogs differ in their ability to interact with RB, we cloned RB cDNA from Atlantic killifish, Fundulus heteroclitus, and studied the interactions of killifish RB protein with killifish AHR1 and AHR2. In coimmunoprecipitation experiments, in vitro-expressed killifish RB coprecipitated with both AHR1 and AHR2. Consistent with these results, both killifish AHR1 and AHR2 interacted with RB in mammalian two-hybrid assays. These results suggest that both fish AHR1 and AHR2 paralogs may have the potential to influence cell proliferation through interactions with RB. [Copyright &y& Elsevier]

Summary: Because diffuse alveolar damage, bronchiolitis obliterans–organizing pneumonia, and usual interstitial pneumonia are all related to acute lung injury, we postulated that the proliferative activity of fibroblasts and epithelium would be similar in all 3, and that of fibroblasts would be similar to skin scars. Ki-67 staining was assessed in 16 usual interstitial pneumonia, 9 bronchiolitis obliterans–organizing pneumonia, and 8 diffuse alveolar damage cases, 5 incidental fibroblast foci, 5 skin scars, and 5 keloids. The proliferative activity of alveolar macrophages was also measured and compared with that of 10 respiratory bronchiolitis cases. The greatest proliferative activity was found in fibroblasts and epithelium of diffuse alveolar damage (25.8% and 41.9%), and it was significantly greater (P = .000) than in usual interstitial pneumonia (1.88% and 2.6%), bronchiolitis obliterans–organizing pneumonia (4.07% and 1.55%), and incidental fibroblast foci (2.9% and 0.44%). The proliferative activity in fibroblasts of diffuse alveolar damage was significantly higher than that of fibroblasts in skin scars (P = .024). In contrast, the proliferative rate of fibroblasts in bronchiolitis obliterans–organizing pneumonia, usual interstitial pneumonia, and incidental fibroblast foci was significantly lower than that in skin scars (P = .000, P = .000, and P = .001) but similar to keloids (P = 1.000). Usual interstitial pneumonia macrophages showed an unexpectedly high proliferative rate (19.5%) that was significantly greater than that in bronchiolitis obliterans–organizing pneumonia (5.5%, P = .000), diffuse alveolar damage (9.01%, P = .007), incidental fibroblast foci (9.5%, P = .036), and respiratory bronchiolitis (11.45%, P = .031). Our results suggest different reactions to acute injury in usual interstitial pneumonia and bronchiolitis obliterans–organizing pneumonia compared with diffuse alveolar damage. The similar low proliferative activity of fibroblasts in usual interstitial pneumonia and keloids supports the hypothesis of abnormal wound healing in usual interstitial pneumonia. The high proliferative activity of macrophages in usual interstitial pneumonia suggests a role in the pathogenesis of usual interstitial pneumonia. [Copyright &y& Elsevier]

Abstract: The retinoblastoma Rb/E2F tumor suppressor pathway plays a major role in the regulation of mammalian cell cycle progression. The pRb protein, along with closely related proteins p107 and p130, exerts its anti-proliferative effects by binding to the E2F family of transcription factors known to regulate essential genes throughout the cell cycle. We sought to investigate the role of the Rb/E2F1 pathway in the lesion recognition step of nucleotide excision repair (NER) in mouse embryonic fibroblasts (MEFs). Rb−/−, p107−/−, p130−/− MEFs repaired both cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs) at higher efficiency than did wildtype cells following UV-C irradiation. The expression of damaged DNA binding gene DDB2 involved in the DNA lesion recognition step was elevated in the Rb family-deficient MEFs. To determine if the enhanced DNA repair in the absence of the Rb gene family is due to the derepression of E2F1, we assayed the ability of E2F1-deficient cells to repair damaged DNA and demonstrated that E2F1−/− MEFs are impaired for the removal of both CPDs and 6-4PPs. Furthermore, wildtype cells induced a higher expression of DDB2 and xeroderma pigmentosum gene XPC transcript levels than did E2F1−/− cells following UV-C irradiation. Using an E2F SiteScan algorithm, we uncovered a putative E2F-responsive element in the XPC promoter upstream of the transcription start site. We showed with chromatin immunoprecipitation assays the binding of E2F1 to the XPC promoter in a UV-dependent manner, suggesting that E2F1 is a transcriptional regulator of XPC. Our study identifies a novel E2F1 gene target and further supports the growing body of evidence that the Rb/E2F1 tumor suppressor pathway is involved in the regulation of the DNA lesion recognition step of nucleotide excision repair. [Copyright &y& Elsevier]

Abstract: In this study the effect of Agrobacterium tumefaciens genotype of two strains AGL1 and LBA4404 was investigated in regard to the propensity for backbone integration during the transformation of potato for blight tolerance conferred by the resistant to blight (RB) gene carried by the vector pCLDO4541. A PCR based walking approach was employed to identify left and right backbone sequences as well as for selected genes carried on the plasmid backbone. It was found that adjacent to the left border insertion site, the integration of backbone sequence was greater for AGL1 than for LBA4404; however, the opposite was observed with regards to the right border T-DNA junction. Considering both T-DNA borders LBA4404 was found to have a two fold greater integration potential for backbone than the AGL1. The possibility of only backbone integration in T-DNA negative plants was also investigated with the average rate of integration between the two strains calculated at 4.2% with LBA4404 recording a three fold greater occurrence of backbone integration than AGL1. In summary, evidence of Agrobacterium genotype dependency showed that LBA4404 has greater potential to integrate non-T-DNA vector sequence than AGL1 and this should be taken into account when utilising the listed A. tumefaciens genotypes in generating transgenic potato. Additionally, the application of a PCR and primer walking system proved to be reliable and allows for fine detailed studies of backbone sequence integration of transgenic plant. [Copyright &y& Elsevier]