Study of TLR3, TLR4 and TLR9 in breast carcinomas and their association with metastasis

<p>Abstract</p> <p>Background</p> <p>Toll-like receptors (TLRs) have garnered an extraordinary amount of interest in cancer research due to their role in tumor progression. By activating the production of several biological factors, TLRs induce type I interferons and other cytokines, which drive an inflammatory response and activate the adaptive immune system. The aim of this study was to investigate the expression and clinical relevance of TLR3, 4 and 9 in breast cancer.</p> <p>Methods</p> <p>The expression levels of TLR3, TLR4 and TLR9 were analyzed on tumors from 74 patients with breast cancer. The analysis was performed by immunohistochemistry.</p> <p>Results</p> <p>Samples of carcinomas with recurrence exhibited a significant increase in the mRNA levels of TLR3, TLR4 and TLR9. Tumors showed high expression of TLRs expression levels by cancer cells, especially TLR4 and 9. Nevertheless, a significant percentage of tumors also showed TLR4 expression by mononuclear inflammatory cells (21.6%) and TLR9 expression by fibroblast-like cells (57.5%). Tumors with high TLR3 expression by tumor cell or with high TLR4 expression by mononuclear inflammatory cells were significantly associated with higher probability of metastasis. However, tumours with high TLR9 expression by fibroblast-like cells were associated with low probability of metastasis.</p> <p>Conclusions</p> <p>The expression levels of TLR3, TLR4 and TLR9 have clinical interest as indicators of tumor aggressiveness in breast cancer. TLRs may represent therapeutic targets in breast cancer.</p

Matrix Metalloproteinase-Induced Epithelial-Mesenchymal Transition in Breast Cancer

Matrix metalloproteinases (MMPs) degrade and modify the extracellular matrix (ECM) as well as cell-ECM and cell-cell contacts, facilitating detachment of epithelial cells from the surrounding tissue. MMPs play key functions in embryonic development and mammary gland branching morphogenesis, but they are also upregulated in breast cancer, where they stimulate tumorigenesis, cancer cell invasion and metastasis. MMPs have been investigated as potential targets for cancer therapy, but clinical trials using broad-spectrum MMP inhibitors yielded disappointing results, due in part to lack of specificity toward individual MMPs and specific stages of tumor development. Epithelial-mesenchymal transition (EMT) is a developmental process in which epithelial cells take on the characteristics of invasive mesenchymal cells, and activation of EMT has been implicated in tumor progression. Recent findings have implicated MMPs as promoters and mediators of developmental and pathogenic EMT processes in the breast. In this review, we will summarize recent studies showing how MMPs activate EMT in mammary gland development and in breast cancer, and how MMPs mediate breast cancer cell motility, invasion, and EMT-driven breast cancer progression. We also suggest approaches to inhibit these MMP-mediated malignant processes for therapeutic benefit

Family history of breast cancer in first-degree relatives and triple-negative breast cancer risk

PURPOSE: Triple-negative breast cancer accounts for less than 20% of breast cancers overall, but is the predominant subtype among carriers of mutations in BRCA1. However, few studies have assessed the association between breast cancer family history and risk of triple-negative breast cancer. We examined the relationship between having a family history of breast cancer in first-degree relatives and risk of triple-negative breast cancer, and risk of two other breast cancer subtypes defined by tumor marker expression. METHODS: We evaluated data collected by the Breast Cancer Surveillance Consortium from 2,599,946 mammograms on 1,054,466 women, among whom 15% reported a first-degree family history of breast cancer. Using Cox regression in this cohort we evaluated subtype-specific associations between family history and risk of triple-negative (N=705), estrogen receptor-positive (ER+, N=10,026), and hormone receptor-negative / HER2-expressing (ER-/PR-/HER2+, N=308) breast cancer among women aged 40-84 years. RESULTS: First-degree family history was similarly and significantly associated with an increased risk of all subtypes [hazard ratio (HR)=1.73, 95% confidence interval (CI): 1.43-2.09, HR=1.62, 95% CI: 1.54-1.70, and HR=1.56, 95% CI: 1.15-2.13, for triple-negative, ER+, and ER-/PR-/HER2+, respectively]. Risk of all subtypes was most pronounced among women with at least two affected first-degree relatives (versus women with no affected first-degree relatives, HR(triple-negative)=2.66, 95% CI: 1.66-4.27, HR(ER+)=2.05, 95% CI: 1.79-2.36, HR(ER-/PR-/HER2+)=2.25, 95% CI: 0.99-5.08). CONCLUSIONS: Having a first-degree family history of breast cancer was associated with an increased risk of triple-negative breast cancer with a magnitude of association similar to that for the predominant ER+ subtype and ER-/PR-/HER2+ breast cancer