MicroRNA implication in therapeutic resistance and metastatic dissemination of bone-associated tumors

Despite the last decade’s improvements in the development of new treatments, mortality of cancer patients is still highly linked to chemoresistance and further occurrence of distant metastasis. The metastatic dissemination is a complex process composed of different steps in which only tumor cells with the highest capacity of adaptation will succeed in establishing and growing at distant sites. Through genetic mutations those cells acquire the chemoresistance features needed to survive in new environments. Nowadays, breast and prostate cancer patients have a risk of being bad responders to chemotherapeutic drugs and to consequently relapse through the development of bone metastasis. Indeed, bone is the most attractive niche for the homing of those cancer cell types. MicroRNAs (miRNAs), a class of small non-coding single strand RNAs, have been recognized as crucial regulatory factors implicated in various cellular processes including cancer initiation and spreading. As miRNAs intensively regulate mediators of migratory and survival pathways, it’s now well established that this class of molecules consequently influences both metastatic dissemination and chemoresistance. Here, we aim to overview the recent research progress on the role of dissemination and chemoresistance-related miRNAs, in the bone-associated tumor context. These pieces of evidence support the clinical use of miRNAs as diagnosis and prognosis markers, as well as potential therapeutic tools against cancer progression, resistance, recurrence and metastatic dissemination.