MicroRNAs in Breast Cancer Bone Metastasis Formation and Progression: An Overview on Recent Progress in This Research Field

Bone metastasis is a common and severe complication in advanced stages of breast cancer (BC) that is characterised by limited treatment options and poor patient prognosis. MicroRNAs (miRNAs) are a large class of regulatory small non-coding RNAs (ncRNAs) expressed by cells. Moreover, miRNAs can be released by cells into the blood and lymphatic streams, acting as distant cell-to-cell communicators. Of note, miRNAs have pivotal roles in the metastatic progression of BC to bone. This review summarises the most recent findings on miRNAs and their mRNA targets in driving BC bone metastasis. Furthermore, the potential clinical uses of miRNAs as future therapeutic targets/agents or biomarkers for BC bone metastasis are discussed.