Preliminary data on microRNA expression profiles in a group of South African patients diagnosed with chronic myeloid leukaemia.

Micro-ribonucleic acids (miRNAs) are small functional non-coding RNAs that downregulate gene expression at the post-transcriptional level. Abnormal expression of specific miRNAs has been recorded in chronic lymphocytic leukaemia, other non-Hodgkin B-cell lymphomas, lung cancer and chronic myeloid leukaemia (CML). The aim of this study was to compare miRNA expression profiles among patients with newly diagnosed CML, those on established therapy with imatinib mesylate, and healthy individuals. The expression of 88 miRNAs was evaluated in a total of nine samples divided into three groups: Group 1 comprised three samples collected from newly diagnosed CML patients; group 2 consisted of three samples collected from patients on therapy; the remaining three samples were collected from healthy volunteers (control group). Total RNA was extracted from whole blood and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was performed on the LightCycler® 480 platform using Human Serum & Plasma miRNA PCR Arrays. In group 1, only SNORD44 was downregulated, while hsa-miR-372 and hsa-miR-375 were found to be significantly upregulated compared with the control group. By contrast, 49 miRNAs were significantly upregulated in group 2 compared with the control group. miRNAs hsa-miR-106b, hsa-miR-21, hsa-miR-221, hsa-miR-10a, hsa-miR-193a-5p and hsa-miR-30e were expressed in group 2. Therefore, miRNA expression profiles differed between the two patient groups.