ABSTRACT
Multiple myeloma (MM) is a hematologic malignancy of differentiated plasma cells that accumulate in the bone marrow,where a complex microenvironment made by different cell types supports proliferation,survival,and drug resistance of tumor cells.MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression at post-transcriptional level.Emerging evidence indicates that miRNAs are aberrantly expressed or functionally deregulated in MM cells as the result of multiple genetic or epigenetic mechanisms and that also the tumor microenvironment regulates MM cell functions by miRNAs.Consistently,modulation of miRNA levels in MM cells has been demonstrated to impair their functional interaction with the bone marrow microenvironment and to produce significant antitumor activity to overcome the protective bone marrowmilieu.This review will describe the most recent findings on miRNA function in the context of MM bone marrow microenvironment,focusing on the therapeutic potential of miRNA-based approaches.