MicroRNAs as main players in the pathogenesis of chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world. The accumulation of mature CD5(+) B-lymphocytes in bone marrow, peripheral blood, and lymphoid organs due to decreased apoptosis is a characteristic of this malignancy. MicroRNAs (miRNAs) are small noncoding RNAs able to regulate the expression of many target genes, including the main apoptosis regulators BCL2 and MCL1. miRNAs play key roles in the pathogenesis of CLL, including specific miRNAs located at the 13q14 chromosomal region that is often deleted or mutated in patients with CLL. In this paper, we review new investigations that underscore the significance of miRNAs for CLL pathogenesis.