microRNAs (miRs) play an important a role in CLL, this study hypothesized that microRNAs are involved in the transition from monoclonal B-cell lymphocytosis (MBL) to CLL and tested miR-15a/ 16-1 cluster, miR-21, and miR-155 expression in purified B cells of normal individuals, individuals with MBL, and patients with CLL.
Researchers analyzed 224 samples from 2 independent training and validation cohorts, they found that miR-155 was overexpressed in B cells from individuals with MBL, and even more so in B cells from patients with CLL, when compared with B cells from normal individuals.
They also found significantly higher miR-155 expression levels in patients who failed to achieve a complete response compared with those who experienced complete response.
In conclusion, ' the study identified miR-155 as a useful marker and highlights its potential to recognize cases of MBL that may progress to overt CLL and patients with CLL that are less likely to respond well to therapy. Prospective assessment of miR-155 levels in individuals with MBL and in patients with CLL who are undergoing treatment, as well as interrogation of a full spectrum of miR-155 targets in CLL B cells, will provide useful insights into the biology of CLL'