Alterations in The Plasma Expression of mir-15b, mir-195 and the Tumor-Suppressor Gene DLEU7 in Patients with B-Cell Chronic Lymphocytic Leukemia

Background : 

Chronic lymphocytic leukemia (CLL) is one of the most prevalent forms of leukemia in adults. Inactivation of the DLEU7 gene is frequently observed in patients with CLL. Furthermore, microRNAs (miRNAs) have been observed to have a critical role in the pathogenesis of several cancers, including leukemia. Considering the tumor-suppressive role of DLEU7, as well as the tumor suppressor or oncogenic role of microRNAs (miRNAs), the aim of the present study was to evaluate the potential miRNAs targeting the DLEU7 gene in B-cells and explore expression changes these genes in the plasma of B-CLL patients.

The miRNAs interacting with the DLEU7 gene were predicted and selected using bioinformatics tools. A total of 80 plasma samples were collected from 40 patients with B-cells and 40 healthy individuals, then subjected to RNA extraction and cDNA synthesis. The expression profiles of the predicted miRNAs and the DLEU7 gene in the plasma of B-CLL patients and healthy individuals were determined by RT-qPCR analysis.

The bioinformatics prediction indicated that miR-15b and miR-195 target the DLEU7 gene. The expression levels of miR-15b and miR-195 were significantly higher in the plasma of patients with BCLL compared to the healthy individuals (91.6, p= 0.001) (169, p= 0.001). However, the expression level of the DLEU7 gene was found to be significantly lower in the patient group compared to healthy controls (0.304, p= 0.001).

Both miR-15b and miR-195, have the potential to function as novel and non-invasive biomarkers in the diagnosis and prognosis of patients with B-CLL.