Role of miRNA-4298/PADI4 axis in the apoptosis of leukemia cells induced by Nrf2 inhibitor 4f / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To investigate the role of miRNA-4298/PADI4/p53 signal axis in mediating 4f-induced apoptosis of leukemia cells.Methods:The cell growth density was observed under inverted microscope and the proliferation of leukemia cells was detected by CCK-8 counting assay. The expression of PADI4 and P53 at mRNA level was detected by qRT-PCR. Cell cycle and apoptosis were measured with flow cytometry. The expression of PADI4, P53, Bcl-2, Bax, caspase-3 and caspase-9 at protein level was detected by Western blot. Differential miRNA and mRNA expression profiles was detected by next generation sequencing. Databases such as TargetScan were used to predict the potential upstream and downstream genes of PADI4. A luciferase reporter assay was used to detect the 3′UTR of PADI4 targeted by miRNA-4298. Cell transfection assay was used to detect the effect siRNA, PADI4 vector, miRNA mimics and miRNA inhibitor in interference and rescue.Results:Nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor 4f could inhibit the proliferation of THP-1, K562 and U937 cells, and induce the apoptosis of these leukemia cells. It downregulated the expression of PADI4 mainly through the binding activity of miRNA-4298 to miRNA sponges, which resulted in the proliferation inhibition and apoptosis of leukemia cells. The inhibited proliferation and apoptosis of leukemia cells by 4f were associated with the increase of P53 expression after the decrease of PADI4 expression. The PADI4-dependent upregulation of P53 led to the ratio inversion of downstream Bcl-2/Bax, which activated caspase-3 or caspase-9 to induce the apoptosis of leukemia cells.Conclusions:The apoptosis of leukemia cells induced by Nrf2 inhibitor 4f was mainly associated with the miRNA-4298/PADI4/p53 axis, suggesting that it might be a novel signaling pathway for targeted therapy.