Almost all genomic studies of breast cancer have focused on well-established tumours because it is technically challenging to study the earliest mutational events occurring in human breast epithelial cells. To address this we created a unique dataset of epithelial samples ductoscopically obtained from ducts leading to breast carcinomas and matched samples from ducts on the opposite side of the nipple. Here, we demonstrate that perturbations in mRNA abundance, with increasing proximity to tumour, cannot be explained by copy number aberrations. Rather, we find a possibility of field cancerization surrounding the primary tumour by constructing a classifier that evaluates where epithelial samples were obtained relative to a tumour (cross-validated micro-averaged AUC = 0.74). We implement a spectral co-clustering algorithm to define biclusters. Relating to over-represented bicluster pathways, we further validate two genes with tissue microarrays and in vitro experiments. We highlight evidence suggesting that bicluster perturbation occurs early in tumour development.
BackgroundBreast cancer is the most common malignancy among women worldwide in terms of incidence and mortality. About 10% of North American women will be diagnosed with breast cancer during their lifetime and 20% of those will die of the disease. Breast cancer is a heterogeneous disease and biomarkers able to correctly classify patients into prognostic groups are needed to better tailor treatment options and improve outcomes. One powerful method used for biomarker discovery is sample screening with mass spectrometry, as it allows direct comparison of protein expression between normal and pathological states. The purpose of this study was to use a systematic and objective method to identify biomarkers with possible prognostic value in breast cancer patients, particularly in identifying cases most likely to have lymph node metastasis and to validate their prognostic ability using breast cancer tissue microarrays.Methods and FindingsDifferential proteomic analyses were employed to identify candidate biomarkers in primary breast cancer patients. These analyses identified decorin (DCN) and endoplasmin (HSP90B1) which play important roles regulating the tumour microenvironment and in pathways related to tumorigenesis. This study indicates that high expression of Decorin is associated with lymph node metastasis (p<0.001), higher number of positive lymph nodes (p<0.0001) and worse overall survival (p = 0.01). High expression of HSP90B1 is associated with distant metastasis (p<0.0001) and decreased overall survival (p<0.0001) these patients also appear to benefit significantly from hormonal treatment.ConclusionsUsing quantitative proteomic profiling of primary breast cancers, two new promising prognostic and predictive markers were found to identify patients with worse survival. In addition HSP90B1 appears to identify a group of patients with distant metastasis with otherwise good prognostic features.
Tumor vascularization is requisite for breast cancer progression, and high microvascular density in tumors is a poor prognostic indicator. Patients bearing breast cancers expressing human embryonic stem cell (hESC)-associated genes similarly exhibit high mortality rates, and the expression of embryonic proteins is associated with tumor progression. Here, we show that Nodal, a hESC-associated protein, promotes breast cancer vascularization. We show that high levels of Nodal are positively correlated with high vascular densities in human breast lesions (P ¼ 0.0078). In vitro, we show that Nodal facilitates breast cancer-induced endothelial cell migration and tube formation, largely by upregulating the expression and secretion of proangiogenic factors by breast cancer cells. Using a directed in vivo angiogenesis assay and a chick chorioallantoic membrane assay, we show that Nodal promotes vascular recruitment in vivo. In a clinically relevant in vivo model, whereby Nodal expression was inhibited following tumor formation, we found a significant reduction in tumor vascularization concomitant with elevated hypoxia and tumor necrosis. These findings establish Nodal as a potential target for the treatment of breast cancer angiogenesis and progression. Cancer Res; 72(15); 3851-63. Ó2012 AACR.
Prostate cancer (PCa) is the second most common cancer in men. Common treatments include active surveillance, surgery, or radiation. Androgen deprivation therapy and chemotherapy are usually reserved for advanced disease or biochemical recurrence, such as castration-resistant prostate cancer (CRPC), but they are not considered curative because PCa cells eventually develop drug resistance. The latter is achieved through various cellular mechanisms that ultimately circumvent the pharmaceutical’s mode of action. The need for novel therapeutic approaches is necessary under these circumstances. An alternative way to treat PCa is by repurposing of existing drugs that were initially intended for other conditions. By extrapolating the effects of previously approved drugs to the intracellular processes of PCa, treatment options will expand. In addition, drug repurposing is cost-effective and efficient because it utilizes drugs that have already demonstrated safety and efficacy. This review catalogues the drugs that can be repurposed for PCa in preclinical studies as well as clinical trials.
Tumour necrosis factor receptor (TNFR)-associated death domain (TRADD) protein is a central adaptor in the TNFR1 signalling complex that mediates both cell death and inflammatory signals. Here, we report that Tradd deficiency in mice accelerated tumour formation in a chemical-induced carcinogenesis model independently of TNFR1 signalling. In vitro, primary cells lacking TRADD were less susceptible to HRas-induced senescence and showed a reduced level of accumulation of the p19(Arf) tumour suppressor protein. Our data indicate that TRADD shuttles dynamically from the cytoplasm into the nucleus to modulate the interaction between p19(Arf) and its E3 ubiquitin ligase ULF, thereby promoting p19(Arf) protein stability and tumour suppression. These results reveal a previously unknown tumour-suppressive role for nuclear TRADD, augmenting its long-established cytoplasmic functions in inflammatory and immune signalling cascades. Our findings also make an important contribution to the rapidly expanding field of p19(Arf) post-translational regulation.
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