OVEREXPRESSION OF MIR-22 DOWN-REGULATED PAPST1 EXPRESSION INHIBITS THE PROLIFERATIVE ACTIVITY OF MEDULLOBLASTOMAS

Shubin Feng, Liujian Dong, Qiang Feng, Qiang Lv, Chaolin Wang, Lin Qi^*

Department of Neurosurgery/Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, PR China

Objective: The study analyzed how the overexpression of microRNA-22 (miR-22) downregulated 3'-adenosine phosphate-5'-phosphate sulfate transporter 1 (PAPST1) inhibited the proliferative activity of medulloblastoma cells in vitro. 

Methods: DAOY cell line medulloblast cells were cultured, and the total RNA of the cells was extracted. A total of 1 μL miR-22 1% overexpression lentivirus solution was added to 200 μL culture medium without serum and antibiotics, then incubated under 37 ℃ to obtain a miR-22 overexpression group as a negative control. Lentivirus-mediated PAPST1 gene expression was disturbed in the infected cells. After 24 h of continuous culture, a PAPST1 control group and PAPST1 interference group were finally obtained. A real-time quantitative PCR method was used to determine miR-22 PAPST1 expression in each group of cells. The CCK-8 method was used to determine the changes in proliferation activity in each group of cells. The expression of PAPST1 cells in the PAPST1 control group and PAPST1 interference group was determined by the Western blot. 

Results: Compared with normal cells, the expression level of miR-22 in DAOY cells decreased significantly, and the expression level of PAPST1 increased significantly (P<0.01). Compared with the control group, the miR-22 expression level was significantly increased and the PAPST1 expression level significantly decreased in the cells of the overexpression group (P<0.01). There was no significant difference in proliferation activity between the two groups at 0 h (P>0.05); Starting from 24h, compared with the control group the cell proliferation activity of the miR-22 overexpression group was significantly reduced. Compared with the PAPST1 control group, the cell proliferation activity of the PAPST1 interference group was significantly reduced (P<0.05 or P<0.01). Compared with the PAPST1 control group, PAPST1 expression level was significantly decreased in the cells of the interference group (P<0.01). 

Conclusions: Overexpression of miR-22 can inhibit the proliferative activity of medulloblastoma cells. PAPST1 is a new biological target of miR-22. Downregulation of PAPST1 expression can inhibit the proliferation activity of medulloblastoma. The inhibitory effect of overexpression miR-22 on the proliferative activity of medulloblastoma cells is achieved by downregulating PAPST1 expression to some extent.