Inside the chronic lymphocytic leukemia cell: miRNA and chromosomal aberrations

Alterations in microRNA (miRNA/miRs) expression are associated with the occurrence and course of human diseases, including chronic lymphocytic leukemia (CLL). Expression of miRNAs may vary among patients with CLL in different cytogenetic risk groups. The present study assessed the expression levels of the following miRNAs in 35 patients with CLL: hsa-miR-15a, −16-1, −29a, −29c, −34a, −34b, −155, −181a, −181b, −221, −222 and −223. Fluorescent in situ hybridization (FISH) analysis was performed for 13q14d, 17p13 and 11q22 deletions and chromosome 12 trisomy. Significantly higher expression levels of miR-181a, −221 and −223 were observed in the group at low risk of disease progression (stage 0) compared with the group with high risk of CLL progression (P=0.036, P=0.019 and P=0.038, respectively). The present study revealed that the expression levels of miRNA-181b and miRNA-223 were significantly higher in the group of patients without D13S319 deletion (P=0.039 and P=0.037, respectively). Moreover, the expression levels of miR-15a and miRNA-29c were demonstrated to be significantly higher in the group of patients with CLL who had a tumor protein p53 deletion, identified by FISH, compared with patients without this lesion (P=0.047, P=0.03 respectively). Based on receiver operating characteristic curve analysis, the present study revealed that miR-181a, −221 and −223 expression was able to distinguish low and high risk of CLL progression in patients. Among the tested miRNAs, miRNA-181a, −221 and −223 were indicated to have the greatest diagnostic potential in CLL.