Investigating the Roles of YWHAB in Breast Cancer

Abstract

Background: miR-526b and miR-655 have been shown to promote aggressive breast cancer phenotypes. Analysis of cell-free secretions of MCF7-miRNA-high cells identified eight differentially secreted proteins, including 14-3-3 Beta (YWHAB). Here, we investigated the roles of YWHAB in breast cancer and tested its potential as a biomarker. Methods: Breast tumor cell lines MCF7, SKBR3, Hs578T, MCF7-COX2 and stable miRNA-overexpressing MCF7-miR526b, MCF7-miR655, SKBR3-526b cells were used in vitro assays including mRNA, protein expression, and functional assays. In silico data was used to support our findings by identifying potential links between miRNAs and YWHAB and to test diagnostic and prognostic biomarker potential. Biomarker potential was validated using breast tumor biopsy tissue and plasma samples. Results: YWHAB expression is significantly upregulated in miRNA-overexpressing cell lines both at total RNA and secretory RNA levels. These miRNAs have previously been shown to increase cell migration. Following YWHAB-KD cell migration and proliferation decreased, E-Cad expression increased, and Vimentin decreased, evidently showing YWHAB involved in EMT. In silico data showed increased expression of YWHAB mRNA in breast cancer biopsy tissue and blood plasma and increased YWHAB protein in breast tumors. High expression of YWHAB is associated with poor breast cancer patient survival. YWHAB expression was measured in breast tissues and blood plasma and found to be significantly high in all advanced stages and hormonal subtypes of tumors, compared to control tissue. YWHABshowed high sensitivity as a tumour biomarker (AUC of 0.7340, p = 0.0012) and in combination with pri-miR526b showed strong potential as a blood biomarker (AUC of 0.711, p = 0.032). Conclusion: High expression of YWHAB is associated with poor survival. It can be used as a prognostic marker, and therapeutic target in aggressive cancers to mitigate cell migration. In combination with pri-miR526b, YWHAB is a promising blood biomarker for breast cancer detection.