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BackgroundImmune-related etiologic pathways that influence breast cancer risk are incompletely understood and may be confounded by lifestyles or reverse causality. Using a Mendelian randomization (MR) approach, we investigated the potential causal relationship between genetically elevated C-reactive protein (CRP) concentrations and primary invasive breast cancer risk in postmenopausal women.MethodsWe used individual-level data obtained from 10,179 women, including 537 who developed breast cancer, from the Women's Health Initiative Database for Genotypes and Phenotypes Study, which consists of five genome-wide association (GWA) studies. We examined 61 GWA single-nucleotide polymorphisms (SNPs) previously associated with CRP. We employed weighted/penalized weighted-medians and MR gene-environment interactions that allow instruments' invalidity to some extent and attenuate the heterogeneous estimates of outlying SNPs.ResultsIn lifestyle-stratification analyses, genetically elevated CRP decreased risk for breast cancer in exogenous estrogen-only, estrogen + progestin, and past oral contraceptive (OC) users, but only among relatively short-term users (

Abstract Background Mounting experimental evidence has shown that the gut microbiota plays a significant role in the pathogenesis of mastitis, and clinical investigations have found that the occurrence of mastitis is correlated with ruminal dysbiosis. However, the underlying mechanism by which the ruminal microbiota participates in the development of mastitis remains unknown. Results In the present study, we found that cows with clinical mastitis had marked systemic inflammation, which was associated with significant ruminal dysbiosis, especially enriched Proteobacteria in the rumen. Ruminal microbiota transplantation from mastitis cows (M-RMT) to mice induced mastitis symptoms in recipient mice along with increased mammary proinflammatory signature activation of the TLR4-cGAS-STING-NF-κB/NLRP3 pathways. M-RMT also induced mucosal inflammation and impaired intestinal barrier integrity, leading to increased endotoxemia and systemic inflammation. Moreover, we showed that M-RMT mirrored ruminal microbiota disruption in the gut of recipient mice, as evidenced by enriched Proteobacteria and similar bacterial functions, which were correlated with most proinflammatory parameters and serum lipopolysaccharide (LPS) levels in mice. Recurrent low-grade LPS treatment mirrored gut dysbiosis-induced endotoxemia and caused severe mastitis in mice. Furthermore, we found that gut dysbiosis-derived LPS reduced host alkaline phosphatase activity by activating neuraminidase (Neu), which facilitates low-grade LPS exposure and E. coli-induced mastitis in mice. Conversely, treatment with calf intestinal alkaline phosphatase or the Neu inhibitor zanamivir alleviated low-grade LPS exposure and E. coli-induced mastitis in mice. Conclusions Our results suggest that ruminal dysbiosis-derived low-grade endotoxemia can cause mastitis and aggravate pathogen-induced mastitis by impairing host anti-inflammatory enzymes, which implies that regulating the ruminal or gut microbiota to prevent low-grade systemic inflammation is a potential strategy for mastitis intervention. Video Abstract

BackgroundImmune-related etiologic pathways that influence breast cancer risk are incompletely understood and may be confounded by lifestyles or reverse causality. Using a Mendelian randomization (MR) approach, we investigated the potential causal relationship between genetically elevated C-reactive protein (CRP) concentrations and primary invasive breast cancer risk in postmenopausal women.MethodsWe used individual-level data obtained from 10,179 women, including 537 who developed breast cancer, from the Women's Health Initiative Database for Genotypes and Phenotypes Study, which consists of five genome-wide association (GWA) studies. We examined 61 GWA single-nucleotide polymorphisms (SNPs) previously associated with CRP. We employed weighted/penalized weighted-medians and MR gene-environment interactions that allow instruments' invalidity to some extent and attenuate the heterogeneous estimates of outlying SNPs.ResultsIn lifestyle-stratification analyses, genetically elevated CRP decreased risk for breast cancer in exogenous estrogen-only, estrogen + progestin, and past oral contraceptive (OC) users, but only among relatively short-term users (

Determination of the mammary epithelial cell that serves as the cell of origin for breast cancer is key to understand tumor heterogeneity and clinical management. In this study, we aimed to decipher whether Rank expression in the presence of PyMT and Neu oncogenes might affect the cell of origin of mammary gland tumors. We observed that Rank expression in PyMT+/− and Neu+/− mammary glands alters the basal and luminal mammary cell populations already in preneoplasic tissue, which may interfere with the tumor cell of origin restricting their tumorigenesis ability upon transplantation assays. In spite of this, Rank expression eventually promotes tumor aggressiveness once tumorigenesis is established. [ABSTRACT FROM AUTHOR]

Mohamad Adham Salkeni,1 Wajeeha Rizvi,2 Kyaw Hein,3 Gerald M Higa4 1Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; 2Department of Internal Medicine, West Virginia University, Morgantown, WV, USA; 3Department of Business, Lamar University, Houston, TX, USA; 4Departments of Clinical Pharmacy and Medicine, West Virginia University, Morgantown, WV, USACorrespondence: Gerald M HigaDepartments of Clinical Pharmacy and Medicine, West Virginia University, Morgantown, WV, 26506, USAEmail ghiga@hsc.wvu.eduAbstract: Even though gene amplification or protein overexpression occurs in approximately one-fifth of all breast cancers, the discovery of HER2 has, nevertheless, had profound implications for the disease. Indeed, the characterization of the receptor resulted in a number of significant advances. Structurally, unique features provided avenues for the development of numerous compounds with target-specificity; molecularly, biological constructs revealed a highly complex, internal signal transduction pathway with regulatory effects on tumor proliferation, survival, and perhaps, even resistance; and clinically, disease outcomes manifested its predictive and prognostic value. Yet despite the receptor’s utility, the beneficial effects are diminished by tumor recurrence after neo- or adjuvant therapy as well as losses resulting from the inability to cure patients with metastatic disease. What these observations suggest is that while tumor response may be partially linked to uncoupling cell surface message reception and nuclear gene expression, as well as recruitment of the innate immune system, disease progression and/or resistance may involve a reprogrammable signaling mainframe that elicits alternative growth and survival signals. This review attempts to meld current perceptions related to HER2-positive metastatic breast cancer with particular attention to current biological insights and therapeutic challenges.Keywords: ado-trastuzumab emtansine, ErbB, Fam-trastuzumab deruxtecan, HER2, lapatinib, margetuximab, neratinib, neu, pertuzumab, PHESGO, trastuzumab, tucatinib

Many tumor-associated antigens (TAAs) represent 'self' antigens and as such, are subject to the constraints of immunologic tolerance. There are significant barriers to eliciting anti-tumor immune responses of sufficient magnitude. We have taken advantage of a Venezuelan equine encephalitis-derived alphavirus replicon vector system with documented in vivo tropism for immune system dendritic cells. We have overcome the intrinsic tolerance to the 'self' TAA rat neu and elicited an effective anti-tumor immune response using this alphavirus replicon vector system and a designed target antigen in a rigorous rat mammary tumor model. We have demonstrated the capacity to generate 50% protection in tumor challenge experiments (p = 0.004) and we have confirmed the establishment of immunologic memory by both second tumor challenge and Winn Assay (p = 0.009). Minor antibody responses were identified and supported the establishment of T helper type 1 (Th1) anti-tumor immune responses by isotype. Animals surviving in excess of 300 days with established effective anti-tumor immunity showed no signs of autoimmune phenomena. Together these experiments support the establishment of T lymphocyte dependent, Th1-biased anti-tumor immune responses to a non-mutated 'self' TAA in an aggressive tumor model. Importantly, this tumor model is subject to the constraints of immunologic tolerance present in animals with normal developmental, temporal, and anatomical expression of a non-mutated TAA. These data support the continued development and potential clinical application of this alphaviral replicon vector system and the use of appropriately designed target antigen sequences for anti-tumor immunotherapy.

Egr-1 is known to function mainly as a tumor suppressor through direct regulation of multiple tumor suppressor genes. To determine the role of Egr-1 in breast tumors in vivo , we used mouse models of breast cancer induced by HER2/neu. We compared neu-overexpressing Egr-1 knockout mice (neu/Egr-1 KO) to neu-overexpressing Egr-1 wild type or heterozygote mice (neu/Egr-1 WT or neu/Egr-1 het) with regard to onset of tumor appearance and number of tumors per mouse. In addition, to examine the role of Egr-1 in vitro , we established neu/Egr-1 WT and KO tumor cell lines derived from breast tumors developed in each mouse. Egr-1 deletion delayed tumor development in vivo and decreased the rate of cell growth in vitro . These results suggest that Egr-1 plays an oncogenic role in HER2/neu-driven mammary tumorigenesis. [ABSTRACT FROM AUTHOR]

Aim: A quick and simple examination can detect early impairment of episodic memory. The aim of the study was to develop an original Czech test which would simulate episodic memory and could be administered without any aids anytime and anywhere. Participants and methods: Participants demonstrated six gestures symbolic for all human senses (twice for sight) as instructed by the administrator in a new test of gestures (TEGEST). Then, they were asked to car ry them out in the same sequence again im mediately and after a 20-min distraction. The TEGEST and Montreal cognitive as ses sment (MoCA) were administered to 25 individuals with mild cognitive impairment and 25 socio-demographical ly paired subjects with normal cognitive functions divided accord - ing to zhe results of neuropsychological tests. Results: Individuals with mild cognitive impairment (MoCA 23 ± 4 points) recal led a signifi cantly smal ler number of gestures than normal elderly people (MoCA 27 ± 3 points): 4 ± 1 vs. 5 ± 1 gestures (p = 0.008). However, the two groups did not diff er in the low number of cor rect sequences of gestures (two). The number or sequence of gestures were not related to age, education, or gender. The number of recalled gestures cor related with the MoCA score (r = 0.7; p = 0.001). The optimal cut-off score was ≤ 4 cor rectly recal led gestures (sensitivity 84%; specifi city 48%; area under the receiver operat ing characteristic curve = 0.70). Conclusion: The novel six-gesture test (TEGEST) is a one- or two-minute and easy-to-use instrument which may signal mild cognitive impairment by four or fewer recal led gestures. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical efficacy of Qiangxinyiqi decoction combined with rosuvastatin in treatment of acute myocardial infarction and the effects on the levels of white blood count (WBC), NEU, myoglobin and C-reactive protein (CRP). Methods: 96 patients with acute myocardial infarction who were treated in our hospital from June 2014 to December 2015 were selected and randomly divided into the observation group and the control group, with 48 cases in each group. The patients in the control group were treated with rosuvastatin, while the patients in the observation group were treated with Qiangxinyiqi decoction on the basis of the control group. Then the clinical efficacy and the indexes of heart function and the levels of white blood count (WBC), NEU, myoglobin and C-reactive protein (CRP) and the adverse reactions between the two groups were observed and compared. Results: The total effective rate in observation group was 89.58%, which was significantly higher than 70.83% in the control group (P<0.05); Compared with before treatment, the levels of LVEF and SV in the two groups significantly increased after the treatment, while the LVEDV decreased (P<0.05); After treatment, the levels of LVEF and SV in the observation group were significantly higher than those of the control group, while the LVEDV was lower (P<0.05); Compared with before treatment, the levels of white blood count (WBC), NEU, myoglobin and C-reactive protein (CRP) in the t6wo groups decreased after the treatment (P<0.05); After treatment, the levels of the white blood count(WBC), NEU, myoglobin and C-reactive protein(CRP) in the observation group were lower than those of the control group (P<0.05); There were no serious adverse reaction in the two groups. Conclusions: Qiangxinyiqi decoction combined with rosuvastatin in treatment of acute myocardial infarction brought has obvious effects which can reduce the levels of white blood count(WBC), NEU, myoglobin and C-reactive protein(CRP), and it is worthy of clinical application. [ABSTRACT FROM AUTHOR]

The main tumor suppressor function of p53 as a ‘guardian of the genome’ is to respond to cellular stress by transcriptional activation of apoptosis, growth arrest or senescence in damaged cells. Not surprisingly, mutations in the p53 gene are the most frequent genetic alteration in human cancers. Importantly, mutant p53 (mutp53) proteins not only lose their wild-type tumor suppressor activity, but also can actively promote tumor development. Two main mechanisms accounting for mutp53 proto-oncogenic activity are inhibition of the wild-type p53 in a dominant-negative fashion and gain of additional oncogenic activities known as gain-of-function (GOF). Here we discuss a novel mechanism of mutp53 GOF, which relies on its oncogenic cooperation with the heat shock machinery. This coordinated adaptive mechanism renders cancer cells more resistant to proteotoxic stress and provides both, a strong survival advantage to cancer cells and a promising means for therapeutic intervention.

Background: Altered tumor cell metabolism is an emerging hallmark of cancer; however, the precise role for glucose in tumor initiation is not known. GLUT1 (SLC2A1) is expressed in breast cancer cells and is likely responsible for avid glucose uptake observed in established tumors. We have shown that GLUT1 was necessary for xenograft tumor formation from primary mammary cells transformed with the polyomavirus middle-T antigen but that it was not necessary for growth after tumors had formed in vivo, suggesting a differential requirement for glucose depending on the stage of tumorigenesis.Methods: To determine whether GLUT1 is required early during mammary tumorigenesis, we crossed MMTV-NIC mice, which express activated HER2/NEU/ERBB2 and Cre recombinase, to Slc2a1 Flox/Flox (GLUT1Flox/Flox) mice to generate NIC-GLUT1+/+, NIC-GLUT1Flox/+, and NIC-GLUT1Flox/Flox mice. In addition, we evaluated effects of glucose restriction or GLUT1 inhibition on transformation in MCF10A-ERBB2 breast epithelial cells in three-dimensional culture. Finally, we utilized global gene expression profiling data of primary human breast tumors to determine the relationship between SLC2A1 and stage of tumorigenesis.Results: All of the NIC-GLUT1+/+ mice developed tumors in less than 200 days. In contrast, only 1 NIC-GLUT1Flox/Flox mouse and 1 NIC-GLUT1Flox/+ mouse developed mammary tumors, even after 18 months. Mammary gland development was not disrupted in NIC mice lacking GLUT1; however, epithelial content of mature glands was reduced compared to NIC-GLUT1Flox/+ mice. In MCF10A-ERBB2 cells, glucose restriction or GLUT1 inhibition blocked transformation induced by activated ERBB2 through reduced cell proliferation. In human breast cancers, SLC2A1 was higher in ductal carcinoma in situ compared to the normal breast, but lower in invasive versus in situ lesions, suggesting the requirement for GLUT1 decreases as tumors progress.Conclusions: This study demonstrates a strict requirement for GLUT1 in the early stages of mammary tumorigenesis in vitro and in vivo. While metabolic adaptation has emerged as a hallmark of cancer, our data indicate that early tumor cells rely heavily on glucose and highlight the potential for glucose restriction as a breast cancer preventive strategy. [ABSTRACT FROM AUTHOR]

To understand the toxicity and the potential role of gamma-radiation (GR) as a therapeutic tool, the effects of different GR doses on haematological and dimensional properties of rats' blood were investigated in vivo. 60 healthy male Wistar-Kyoto rats were used in this study, and were randomly divided into 5 groups, 4GR rat groups (1st group was radiated with 5GR, 2nd group 25Gy; 3rd group with 50Gy, 4th group with 100Gy and 5th group was the control). Different haematological and dimensional parameters were measured using the standard haematological technique for complete blood count (CBC). A significant decrease in white blood cells (WBCs) count and lymphocytes (LYM) was observed compared with the control. While a significant increase in monocytes (MON), neutrophils (NEU), basophils (BAS), and eosinophils (EOS) were observed. A non-significant decrease in platelets (PLTs) count was observed with GR compared with the control. [ABSTRACT FROM AUTHOR]

The main tumor suppressor function of p53 as a "guardian of the genome" is to respond to cellular stress by transcriptional activation of apoptosis, growth arrest, or senescence in damaged cells. Not surprisingly, mutations in the p53 gene are the most frequent genetic alteration in human cancers. Importantly, mutant p53 (mutp53) proteins not only lose their wild-type tumor suppressor activity but also can actively promote tumor development. Two main mechanisms accounting for mutp53 proto-oncogenic activity are inhibition of the wild-type p53 in a dominant-negative fashion and gain of additional oncogenic activities known as gain-of-function (GOF). Here, we discuss a novel mechanism of mutp53 GOF, which relies on its oncogenic cooperation with the heat shock machinery. This coordinated adaptive mechanism renders cancer cells more resistant to proteotoxic stress and provides both, a strong survival advantage to cancer cells and a promising means for therapeutic intervention. [ABSTRACT FROM AUTHOR]

C-erbB2/HER2 serves as an important prognostic and predictive biomarker in various human tumors, especially in breast cancer, whereas its role in human intracranial tumors is more uncertain. We therefore performed a search in PubMed to get an update. This literature review comprises immunohistochemical studies on the clinical significance of c-erbB2/HER2 overexpression in gliomas, medulloblastomas, and meningiomas. In general, the findings were discrepant with regard to correlations between overexpression, tumor grade, and prognosis. Use of various antibodies may be a contributing factor to these discrepancies. Standardization of the immunohistochemical procedures is a relevant topic for discussion. [ABSTRACT FROM PUBLISHER]

Grb7 is an adaptor molecule mediating signal transduction from multiple cell surface receptors to diverse downstream pathways. Grb7, along with Grb10 and Grb14, make up the Grb7 protein family. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7 and a receptor tyrosine kinase, ErbB2, are overexpressed in 20-30% of breast cancers. Grb7 overexpression has been linked to enhanced cell migration and metastasis, although the participants in these pathways have not been fully determined. In this study, we report the Grb7 protein interacts with Filamin-a, an actin-crosslinking component of the cell cytoskeleton. Additionally, we have demonstrated the interaction between Grb7 and Flna is specific to the RA-PH domains of Grb7, and the immunoglobulin-like repeat 16-19 domains of Flna. We demonstrate that full-length Grb7 and Flna interact in the mammalian cellular environment, as well as in vitro. Immunofluorescent microscopy shows potential colocalization of Grb7 and Flna in membrane ruffles upon epidermal growth factor stimulation. These studies are amongst the first to establish a clear connection between Grb7 signaling and cytoskeletal remodeling. [ABSTRACT FROM AUTHOR]

In previous studies, we showed that the tyrosine phosphorylation state of growth factor receptor-bound protein 7 (Grb7) affects its ability to bind to the transcription regulator FHL2 and the cortactin-interacting protein, human HS-1-associated protein-1. Here, we present results describing the importance of dimerization in the Grb7-Src homology 2 (SH2) domain in terms of its structural integrity and the ability to bind phosphorylated tyrosine peptide ligands. A tyrosine phosphorylation-mimic mutant (Y80E-Grb7-SH2) is largely dimerization deficient and binds a tyrosine-phosphorylated peptide representative of the receptor tyrosine kinase (RTK) erbB2 with differing thermodynamic characteristics than the wild-type SH2 domain. Another dimerization-deficient mutant (F99R-Grb7-SH2) binds the phosphorylated erbB2 peptide with similarly changed thermodynamic characteristics. Both Y80E-Grb7-SH2 and F99R-Grb7-SH2 are structured by circular dichroism measurements but show reduced thermal stability relative to the wild type-Grb7-SH2 domain as measured by circular dichroism and nuclear magnetic resonance. It is well known that the dimerization state of RTKs (as binding partners to adaptor proteins such as Grb7) plays an important role in their regulation. Here, we propose the phosphorylation state of Grb7-SH2 domain tyrosine residues could control Grb7 dimerization, and dimerization may be an important regulatory step in Grb7 binding to RTKs such as erbB2. In this manner, additional dimerization-dependent regulation could occur downstream of the membrane-bound kinase in RTK-mediated signaling pathways. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Dimerization is a critical requirement for the activation of the intracellular kinase domains of receptor tyrosine kinases (RTKs). The single transmembrane (TM) helices of RTKs contribute to dimerization, but the details are not well understood. Work with TM helices in various model systems has revealed a small number of specific dimerization sequence motifs, and it has been suggested that RTK dimerization is modulated by such motifs. Yet questions remain about the universality of these sequence motifs for RTK dimerization and about how TM domain dimerization in model systems relates to RTK activation in mammalian membranes. To investigate these questions, we designed a 3888-member combinatorial peptide library based on the TM domain of Neu (ErbB2) as a model RTK. The library contains many closely related, Neu-like sequences, including thousands of sequences with known dimerization motifs. We used an SDS-PAGE-based screen to select peptides that dimerize better than the native Neu sequence, and we assayed the activation of chimeric Neu receptors in mammalian cells with TM sequences selected in the screen. Despite the very high abundance of known dimerization motifs in the library, only a very few dimerizing sequences were identified by SDS-PAGE. About half of those sequences activated the Neu kinase significantly more than did the wild-type TM sequence. This work furthers our knowledge about the requirements for membrane protein interactions and the requirements for RTK activation in cells. [Copyright &y& Elsevier]

The article discusses a study which identified the interaction partners of Grb7 adaptor protein potentially involved in focal adhesion kinase (FAK)/Grb7-mediated cell migration. It clarifies the role of the Grb7-Ras Associating (RA) and -Pleckstrin Homology (PH) domains in this protein and explores the phosphorylation state of Grb7 necessary for, or during, binding interactions. It also proposes a Grb7autoinhibitory mechanism based upon the results.

Abstract: Numerous synthetic vitamin D analogs have been studied for their effects on the prevention and treatment of breast cancer. However, the inhibitory effects of naturally occurring 1α,25-dihydroxyvitamin D3 or its synthetic analogs on ErbB2 overexpressing mammary tumorigenesis have not been reported. Gemini vitamin D analogs are novel synthetic vitamin D derivatives with a unique structure of two six-carbon chains at C-20. We have previously shown that Gemini vitamin D analogs significantly inhibited carcinogen-induced estrogen receptor (ER)-positive mammary tumorigenesis and reduced ER-negative MCF10DCIS.com xenograft tumor growth without hypercalcemic toxicity. In the present study, we have determined the inhibitory effect of a potent Gemini vitamin D analog BXL0124 (1α,25-dihydroxy-20R-21(3-hydroxy-3-deuteromethyl-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-cholecalciferol) on the ErbB2/Her-2/neu overexpressing mammary tumorigenesis. The Gemini BXL0124 inhibits ErbB2-positive mammary tumor growth and down-regulates the phosphorylation of ErbB2, ERK and AKT in tumors of MMTV-ErbB2/neu transgenic mice. These effects of Gemini BXL0124 in vivo were confirmed by using the ErbB2 overexpressing tumor cells derived from the mammary tumors of MMTV-ErbB2/neu mice. In conclusion, the Gemini vitamin D analog BXL0124 inhibits the growth of ErbB2 overexpressing mammary tumors through regulating the ErbB2/AKT/ERK signaling pathways, suggesting that Gemini vitamin D analog may be considered for translational studies. [ABSTRACT FROM AUTHOR]

LI Y.G. & GENG X. (2010) European Journal of Cancer Care 19, 313–316 A meta-analysis on the association of HER-2 overexpression with prognosis in human osteosarcoma Various studies examining the relationship between HER-2 overexpression and clinical outcome in patients with osteosarcoma have yielded inconclusive results. The purpose of the current study was to evaluate the relation of HER-2 status with clinical outcome in osteosarcoma. We conducted a meta-analysis of five studies that evaluated the relation between HER-2 status and 2-year survival. DerSimonian-Laird random effects analysis was used to estimate the effects of HER-2 overexpression on 2-year survival. The combined relative risk in patients with osteosarcoma for 2-year survival was 1.26 (95% confidence interval, 0.50–3.14; P = 0.63). HER-2-positive status tended to be associated with a worse 2-year survival, but the overall results were not formally statistically significant. An unfavourable prognostic effect of HER-2 overexpression in osteosarcoma was evident from the meta-analysis. However, because several studies were excluded by the current eligibility criteria, caution is needed in interpreting the results. [ABSTRACT FROM AUTHOR]

Female mice transgenic for the rat proto-oncogene c-erb-B2, under control of the mouse mammary tumor virus (MMTV) promoter (neuN), spontaneously develop metastatic mammary carcinomas. The development of these mammary tumors is associated with increased number of GR-1+CD11b+ myeloid derived suppressor cells (MDSCs) in the peripheral blood (PB), spleen and tumor. We report a complex relationship between tumor growth, MDSCs and immune regulatory molecules in non-mutated neu transgenic mice on a FVB background (FVB-neuN). The first and second tumors in FVB-neuN mice develop at a median of 265 (147–579) and 329 (161–523) days, respectively, resulting in a median survival time (MST) of 432 (201 to >500) days. During tumor growth, significantly increased number of MDSCs is observed in the PB and spleen, as well as, in infiltrating the mammary tumors. Our results demonstrate a direct correlation between tumor size and the number of MDSCs infiltrating the tumor and an inverse relationship between the frequency of CD4+ T-cells and MDSCs in the spleen. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assessment of enzyme and cytokine transcript levels in the spleen, tumor, tumor-infiltrating non-parenchymal cells (NPCs) and mammary glands revealed a significant increase in transcript levels from grossly normal mammary glands and tumor-infiltrating NPCs during tumor progression. Tumor NPCs, as compared to spleen cells from wild-type (w/t) mice, expressed significantly higher levels of arginase-1 (ARG-1), nitric oxide synthase (NOS-2), vascular endothelial growth factor (VEGF-A) and significantly lower levels of interferon (IFN)-γ, interleukin (IL)-2 and fms-like tyrosine kinase-3 ligand (Flt3L) transcript levels. Transcript levels in the spleens of tumor-bearing (TB) mice also differed from normal mice, although to a lesser extent than transcript levels from tumor-infiltrating NPCs. Furthermore, both spleen cells and NPCs from TB mice, but not control mice, suppressed alloantigen responses by syngeneic control spleen cells. Correlative studies revealed that the number of MDSCs in the spleen was directly associated with granulocyte colony stimulating factor (G-CSF) transcript levels in the spleen; while the number of MDSCs in the tumors was directly correlated with splenic granulocyte macrophage stimulating factor (GM-CSF) transcript levels, tumor volume and tumor cell number. Together our results support a role for MDSCs in tumor initiation and progressive, T-cell depression and loss of function provide evidence which support multiple mechanisms of MDSC expansion in a site-dependent manner. [ABSTRACT FROM AUTHOR]

Abstract: Receptor tyrosine kinases (RTKs) are the second largest family of membrane receptors and play a key role in the regulation of vital cellular processes, such as control of cell growth, differentiation, metabolism, and migration. The production of whole-length RTKs in large quantities for biophysical or structural characterization, however, is a challenge. In this study, a cell engineering strategy using the anti-apoptotic Bcl-2 family protein, Bcl-xL, was tested as a potential method for increasing stable expression levels of a recombinant RTK membrane protein in Chinese hamster ovary (CHO) cells. Wild-type and CHO cells stably overexpressing heterologous Bcl-xL were transformed with the gene for a model RTK membrane protein, ErbB2, on a plasmid also containing the Zeocin resistance gene. While CHO cells exhibited a gradual decrease in expression with passaging, CHO-bcl-xL cells offered an increased and sustained level of ErbB2 expression following continuous passaging over more than 33days in culture. The increased ErbB2 expression in CHO-bcl-xL cells was evident both in stable transfected pools and in clonal isolates, and demonstrated both in Western blot analysis and flow cytometry. Furthermore, the sustained high-level protein expression in CHO-bcl-xL cells does not alter the correct membrane localization of the ErbB2 protein. Our results demonstrate that cellular engineering, specifically anti-apoptosis engineering, can provide increased and stable ErbB2 membrane protein expression in mammalian cells. This approach may also be useful for other membrane proteins in which large quantities are needed for biophysical and structural studies. [Copyright &y& Elsevier]

Direct comparison and ranking of vaccine formulations in pre-clinical studies will expedite the identification of cancer vaccines for clinical trials. Two human ErbB-2 (Her-2) vaccines, naked DNA and whole cell vaccine, were tested side-by-side in wild type and Her-2 transgenic mice. Both vaccines can induce humoral and cellular immunity to the entire repertoire of Her-2 epitopes. Mice were electro-vaccinated i.m. with a mixture of pGM-CSF and pE2TM, the latter encodes Her-2 extracellular and transmembrane domains. Alternatively, mice were injected i.p. with human ovarian cancer SKOV3 cells that have amplified Her-2. In wild type mice, comparable levels of Her-2 antibodies (Ab) were induced by these two vaccines. However, T cell immunity and protection against Her-2+ tumors were superior in DNA vaccinated mice. In BALB Her-2 transgenic (Tg) mice, which were tolerant to Her-2, DNA and cell vaccines were administered after regulatory T cells (Treg) were removed by anti-CD25 mAb. Again, comparable levels of Her-2 Ab were induced, but DNA vaccines rendered greater anti-tumor activity. In B6xDR3 Her-2 Tg mice that expressed the autoimmune prone HLA-DR3 allele, higher levels of Her-2 Ab were induced by SKOV3 cell than by Her-2 DNA. But anti-tumor activity was still more profound in DNA vaccinated mice. Therefore, Her-2 DNA vaccine induced greater anti-tumor immunity than cell vaccine, whether mice were tolerant to Her-2 or susceptible to autoimmunity. Through such side-by-side comparisons in appropriate pre-clinical test systems, the more effective vaccine formulations will emerge as candidates for clinical trials. [ABSTRACT FROM AUTHOR]

Rho-like small GTPases, including RhoA, Rac1 and Cdc42, are crucial for the regulation of a large variety of biological processes such as the cytoskeletal organization and gene transcription. The activities of Rho GTPases are predominantly controlled by guanine nucleotide exchange factors (GEFs), which activate GTPases by catalyzing the exchange of bound GDP for GTP. Earlier, we have identified the Tiam1 gene as an invasion-inducing gene that encodes a specific activator (GEF) of the Rac GTPase. We found that Tiam1-mediated Rac signaling functions in various aspects of tumorigenicity including the formation and progression of Ras-induced skin tumors and Wnt-induced intestinal tumors. Here, we further distinguish the oncogenic pathways that depend on Tiam1 signaling in the mammary gland. We crossed Tiam1 knockout mice with MMTV-c- myc and MMTV-c- neu transgenic mice, in which the expression of both oncogenes is targeted to the mammary gland leading to mammary tumorigenesis. We found Tiam1 important for Neu-induced tumor formation and progression but not for Myc-induced tumors. Tiam1-deficiency delayed Neu-induced tumor initiation and reduced metastasis but had no effect on the growth of the MMTV-c- neu tumors. Our data indicate that the Rac activator Tiam1 contributes to tumorigenicity induced by specific oncogenic signaling pathways only. [ABSTRACT FROM AUTHOR]

Various studies examining the relationship between HER-2 over-expression and the response to chemotherapy and clinical outcome in patients with osteosarcoma have yielded inconclusive results. The purpose of the current study was to evaluate the relation of HER-2 status with the response to chemotherapy and clinical outcome in osteosarcoma. We conducted a meta-analysis of 6 studies that evaluated the correlation between HER-2 status and histologic response to chemotherapy and 2-year survival. Data were synthesized in summary receiver operating characteristic curves and with summary likelihood ratios (LRs) and relative risk. The quantitative synthesis showed that HER-2 status is not a prognostic factor for the response to chemotherapy. The positive LR was 1.27 (95% confidence interval, 0.91∼1.77), and the negative LR was 0.68 (95% confidence interval, 0.38∼1.22). There was no significant between-study heterogeneity. HER2-positive status tended to be associated with a worse 2-year survival, but the overall results were not formally statistically significant. HER-2 status is not associated with the histologic response to chemotherapy in patients with osteosarcoma, whereas HER-2 positive patients may be associated with decreased survival. [ABSTRACT FROM AUTHOR]

The receptor-type protein tyrosine phosphatase epsilon (RPTPɛ) activates c-Src in mammary tumor cells induced in vivo by Neu. Tumor cells lacking RPTPɛ exhibit reduced c-Src activity, appear less transformed morphologically and proliferate slower in vitro and in vivo. Expression of Src rescues most of these phenotypes, indicating that c-Src activity is important for maintaining the transformed phenotype. However, the molecular mechanisms that control activation of c-Src by RPTPɛ are unknown. We show that Neu induces phosphorylation of RPTPɛ exclusively at its C-terminal Y695, and that this phosphorylation is required for activation of c-Src by RPTPɛ. Phosphorylation of RPTPɛ does not affect its activity toward another substrate, the voltage-gated potassium channel Kv2.1, suggesting that phosphorylation directs RPTPɛ activity toward c-Src. Phosphorylation of RPTPɛ reduces its dimerization at the cell membrane, although this does not affect its activity significantly. RPTPɛ is subject to strong auto- and trans-dephosphorylation, suggesting that dephosphorylation limits the activation of c-Src downstream of Neu. We conclude that an Neu-RPTPɛ-Src signaling pathway exists in mammary tumor cells, in which phosphorylation of RPTPɛ by Neu directs RPTPɛ to activate c-Src. Reversible phosphorylation of RPTPɛ at Y695 may thus function as a ‘molecular switch’, which affects the substrate specificity of the phosphatase.Oncogene (2007) 26, 7028–7037; doi:10.1038/sj.onc.1210505; published online 7 May 2007 [ABSTRACT FROM AUTHOR]

The year 2007 marks exactly two decades since Human Epidermal Growth Factor Receptor-2 (HER2) was functionally implicated in the pathogenesis of human breast cancer. This finding established the HER2 oncogene hypothesis for the development of some human cancers. The subsequent two decades have brought about an explosion of information about the biology of HER2 and the HER family. An abundance of experimental evidence now solidly supports the HER2 oncogene hypothesis and etiologically links amplification of the HER2 gene locus with human cancer pathogenesis. The molecular mechanisms underlying HER2 tumorigenesis appear to be complex and a unified mechanistic model of HER2-induced transformation has not emerged. Numerous hypotheses implicating diverse transforming pathways have been proposed and are individually supported by experimental models and HER2 may indeed induce cell transformation through multiple mechanisms. Here I review the evidence supporting the oncogenic function of HER2, the mechanisms that are felt to mediate its oncogenic functions, and the evidence that links the experimental evidence with human cancer pathogenesis.Oncogene (2007) 26, 6469–6487; doi:10.1038/sj.onc.1210477; published online 30 April 2007 [ABSTRACT FROM AUTHOR]

Abstract: We examined the therapeutic efficacy of xenogenic human N′-terminal neu DNA vaccine and autologous mouse N′-terminal neu DNA vaccine on MBT-2 tumor cells in C3H mice. Intramuscular injection of xenogenic and autologous neu DNA vaccines produced comparable therapeutic efficacies. Mouse and human N′-neu DNA vaccine induced tumor infiltration of CD8+ T cells, while the human vaccine was less effective at stimulating natural killer cells. Depletion of CD8+ T cells abolished the therapeutic efficacy of both types of DNA vaccines. On the other hand, xenogenic neu DNA vaccine showed significantly better therapeutic efficacy than autologous DNA vaccine with gene gun immunization. Increased infiltration of CD8+ T cells was correlated with enhanced therapeutic efficacy in the human N′-neu group of mice. Therefore, intramuscular injection can enhance the therapeutic efficacy of autologous neu DNA vaccine. [Copyright &y& Elsevier]

Summary: Experimental evidence suggests that in lung cancer, development, progression and an increased proliferation rate can be linked to apoptosis-related factors. The objective of this study is to evaluate the status of Neu, signal transducer and activator of transcription (STAT)-3, STAT5 and Bcl-xL expression in non-small-cell lung cancer. We investigated the immunohistochemical expression of these proteins in 92 non-small-cell lung cancer specimens to establish their role in lung cancer pathogenesis. Neu was overexpressed in 65% of cases, and although STAT3 was overexpressed in 52.1% in cytoplasm, it was expressed in nucleus (activated) in 60.8%. Meanwhile, STAT5 was found overexpressed in 41.3% in cytoplasm and 32.6% in nucleus. Thus, Bcl-xL was overexpressed in cytoplasm in 81.5%. Interestingly, we found nuclear expression of Bcl-xL in 30.4% of cases. Finally, we found correlation among histological types of lung cancer and nuclear expression of both STAT5 (P =0.005) and nuclear Bcl-xL (P =0.003). Besides, nuclear expression of Bcl-xL was correlated with TNM stage IV (distant metastasis) (P =0.02). These results suggest for the first time, a relevant role for STAT5 and Bcl-xL as apoptosis-regulatory proteins in the pathogenesis of lung cancer, and overexpression of both Neu and activated STAT3, could be related with the proliferation rate in lung carcinoma cells. [Copyright &y& Elsevier]

Abstract: ErbB-2 is a member of the family of epidermal growth factor receptors, which shows an oncogenic mutation in the rat gene neu, Val664Glu in the transmembrane domain that causes permanent dimerisation and subsequently leads to uncontrollable cell division and tumour formation. We have obtained the α-helical structure of the mutant transmembrane domain dimer experimentally with site-specific infrared dichroism (SSID) based on six transmembrane peptides with 13C18O carbonyl group-labelled residues. The derived orientational data indicate a local helix tilt ranging from 28(±6)° to 22(±4)°. Altogether using orientational constraints from SSID and experimental α-helical constraints while performing a systematic conformational search including molecular dynamics simulation in a lipid bilayer, we have obtained a unique experimentally defined atomic structure. The resulting structure consists of a right handed α-helical bundle with the residues Ile659, Val663, Leu667, Ile671, Val674 and Leu679 in the dimerisation interface. The right-handed bundle is in contrast to the left-handed structures obtained in previous modelling efforts. In order to facilitate tight helical packing, the spacious Glu664 residues do not interact directly but with water molecules that enter the bilayer. [Copyright &y& Elsevier]