MicroRNAs and drug resistance

MicroRNA alterations are involved in the initiation, progression, and metastases of human cancer. The main molecular alterations are represented by variations in gene expression, usually mild and with consequences for a vast number of target protein coding genes. MicroRNA expression profiling of human tumors has identified signatures associated with diagnosis, staging, progression, prognosis, and response to treatment. Recent studies proved that miRNAs are involved in resistance to chemotherapy and therefore understanding their involvement could be of benefit for cancer patients' treatment. This chapter's focus is on the main studies proving the new link between microRNAs and drug resistance.