[Expression Level and Target Gene Prediction of miR-181b in Patients with Chronic Lymphocytic Leukemia]

To investigate the expression level of miR-181b in CD19+ B lymphocytes of patients with chronic lymphocytic leukemia (CLL), to analyze the relationship between its expression and the prognosis of CLL patients, and to predict the potential target gene of miR-181b in CLL by using bioinformatics.

Eight-four patients with CLL treated in People's Hospital of Xinjiang Uygur Autonomous Region from June 2013 to June 2018 were selected. and 20 healthy people were selected as control group. RNA was extracted from CD19+B lymphocytes of peripheral blood by magnetic bead sorting, the expression level of miR-181b was detected, and it's expression differences in different IPI groups were analyzed. The correlation between the expression level of miR-181b and PFS of CLL patients also was analyzed. miR-181b target genes were predicted by online database and literatures, and gene annotation analysis and relevant signal pathway analysis were performed for candidate target genes.

The expression level of miR-181b in CLL patients was significantly lower than that in control group (P＜0.01); The expression level of miR-181b in the low-risk group was higher than that in high-risk group and extremely high-risk group (P＜0.05), but there was no statistical difference between low-risk group and medium-risk group (P=1.00). The expression level of miR-181b in medium-risk group was higher than that in high-risk group and extremely high-risk group (P＜0.05), but there was no difference between high-risk group and extremely high-risk group (P=1.00). ROC curve results showed that the area under the curve (AUC) was 0.792 (P＜0.01).When the expression level of miR-181b was at the threshold value of 0.279, it showed a better sensitivity (62.9%) and specificity (91.8%). Survival analysis results suggested that compared with the high expression group, the miR-181b low expression group had poor PFS (log rank: P=0.047). Prediction of miR-181b by using the starBase, targetscan and picTar database and its combination with literature reports indicated that CARD11, ZFP36L1, RUNX1, NR4A3, ATP1B1, PUM1 and PLAG1 related with blood diseases, and up-regulated CARD11 and ZFP36L1 participated in lymphoid tumor formation by promoting cell proliferation and inhibiting cell aging.

The expression level of miR-181b in CLL group are significantly lower than that in the controls group, and the low expression of miR-181b relates with poor prognosis of CLL patients. Through bioinformatics prediction and combined with literature reports, it is speculated that CARD11 and ZFP36L1 as target genes of miR-181b may be participated in the occurrence and development of CLL. Further experiments are needed to verify this result.