Duplicitous Dispositions of Micro-RNAs (miRs) in Breast Cancer

Abstract

In 1993, a gene silencer known as lin-4 was first discovered in Caenorhabditis elegans and demonstrated to be critical for larval development. Lin-4 belongs to a family of signaling molecules known as non-protein coding microRNAs (miRNAs) which are not only highly conserved in humans, but also involved in the fundamental processes of oncogenesis. While miRNAs are not translated to proteins themselves, they are capable of regulating the expression and translation of other genes thus affecting a multitude of biological and pathological pathways as well as those essential to the malignant landscape. The aim of this chapter is to explore the diverse roles of miRNAs in the context of breast cancer. Following a brief overview of miRNA biogenesis, this chapter covers the production of miRNAs by tumor cells and stromal cells, onco-suppressor miRNAs, use as therapeutics, contribution to therapeutic resistance, and finally their emerging role as biomarkers.

Translational Implications of Dysregulated Pathways and microRNA Regulation in Quadruple-Negative Breast Cancer

“…Differential expression profiles and pathway regulation in breast cancer and TNBC in particular are integrated with the expression and regulation of transcriptional profiles by microRNAs (miRNA) [ 6 ]. Importantly in the context of AR-positive breast cancers and QNBC, recent efforts have identified androgen-responsive miRNAs, the expression of specific miRNAs and miRNA expression profiles that are associated with AR expression in breast cancer [ 7 , 8 , 9 ].…”