A Prospective Tumour Marker for Breast Cancer: YWHAB and Its Role in Promoting Oncogenic Phenotypes.

Background: YWHAB (14-3-3 Beta) was found in the secretome of miR-526b and miR-655 overexpressed breast cancer (BRCA) cell lines. The potential of YWHAB as a therapeutic target or biomarker for BRCA is investigated here.

Methods: After YWHAB was knocked down with siRNA, BRCA cell lines were used for in vitro assays (proliferation, migration, epithelial-to-mesenchymal transition).

Breast cancer cell secretome analysis to decipher miRNA regulating the tumor microenvironment and discover potential biomarkers.

MicroRNA (miRNA/miR) 526 b- and miR655-overexpressed tumor cell-free secretions regulate the breast cancer tumor microenvironment (TME) by promoting tumor-associated angiogenesis, oxidative stress, and hypoxic responses. Additionally, premature miRNA (pri-miR526b and pri-miR655) are established breast cancer blood biomarkers. However, the mechanisms of how these miRNAs regulate the TME has yet to be investigated.

Prostaglandin E2 Receptor 4 (EP4) as a Therapeutic Target to Impede Breast Cancer-Associated Angiogenesis and Lymphangiogenesis.

The formation of new blood (angiogenesis) and lymphatic (lymphangiogenesis) vessels are major events associated with most epithelial malignancies, including breast cancer. Angiogenesis is essential for cancer cell survival. Lymphangiogenesis is critical in maintaining tumoral interstitial fluid balance and importing tumor-facilitatory immune cells.

Chemically Induced Hypoxia Enhances miRNA Functions in Breast Cancer.

In aggressively growing tumors, hypoxia induces HIF-1α expression promoting angiogenesis. Previously, we have shown that overexpression of oncogenic microRNAs (miRNAs, miRs) miR526b/miR655 in poorly metastatic breast cancer cell lines promotes aggressive cancer phenotypes in vitro and in vivo. Additionally, miR526b/miR655 expression is significantly higher in human breast tumors, and high miR526b/miR655 expression is associated with poor prognosis.