[Molecular Mechanism of circVRK1 Regulating the Proliferation and Apoptosis of Acute Lymphoblastic Leukemia KOCL44 Cells by Targeting miR-4428].

OBJECTIVE

To elucidate the role of circVRK1 and its interaction with miR-4428 in regulating proliferation and apoptosis in acute lymphoblastic leukemia (ALL) cells.

METHODS

KOCL44 ALL cells were cultured , and experimental groups included pcDNA, pcDNA-circVRK1, anti-miR-NC, anti-miR-4428, si-NC, si-circVRK1, pcDNA-circVRK1+miR-NC, and pcDNA-circVRK1+miR-4428. The expression levels of circVRK1 and miR-4428 were detected using qRT-PCR. CCK-8 assays and flow cytometry were used to assess cell proliferation and apoptosis, respectively. The dual luciferase reporter assays were employed to investigate the interaction between circVRK1 and miR-4428, with groups categorized as WT-circVRK1+miR-NC, WT-circVRK1+miR-4428, MUT-circVRK1+miR-NC, and MUT-circVRK1+ miR-4428. Western blotting was utilized to detect the expression levels of Ki-67, cleaved caspase-3, and cleaved caspase-9 proteins.

RESULTS

Compared to the pcDNA group, circVRK1 expression was up-regulated in the pcDNA-circVRK1 group (<0.05). Compared to transfection with pcDNA or anti-miR-NC, transfection with pcDNA-circVRK1 or anti-miR-4428 led to decreased cell viability and Ki-67 protein levels in KOCL44 cells (<0.05), and increased apoptosis rates and levels of cleaved caspase-3 and cleaved caspase-9 (<0.05). circVRK1 was found to negatively regulate miR-4428 expression, with this effect observed only in the WT-circVRK1 group. miR-4428 levels were lower in the pcDNA-circVRK1 group compared to the pcDNA group (<0.05) and higher in the si-circVRK1 group compared to the si-NC group (<0.05). Co-transfection with pcDNA-circVRK1+miR-4428 resulted in increased cell viability (<0.05) and Ki-67 expression (<0.05), and decreased apoptosis rates and levels of cleaved caspase-3 and cleaved caspase-9 (<0.05) compared to co-transfection with pcDNA-circVRK1+miR-NC.

CONCLUSION

Overexpression of circVRK1 reduces the proliferation ability of acute ALL cells and induces cell apoptosis by downregulating miR-4428 expression.