microRNAs (miRNAs) have a crucial role in erythropoiesis. However, the understanding of the apoptosis of erythroid lineage remains poorly understood. Hence, an additional examination is required. K562 cell lines can be differentiated into early erythrocytes by hemin and the model of early erythrocytes can be established, consequently. miR-196a has been proven to take part in antiapoptosis in many cell lines. However, the role of miR-196a associated with the apoptosis in hemin-induced K562 cells remains unclear. To study the potential function of miR-196a involved in the common progenitor of erythroblasts, miR-196a mimics and microRNA-small hairpin negative control (miRNA-ShNC) were transfected into hemin-induced K562 cells with lentiviruses. After that, the viability of the transfected hemin-induced K562 cells was tested by CCK-8 assay, and the alteration of cell cycle and apoptosis rate were detected by flow cytometry. Furthermore, bioinformatics and dual-luciferase report system verified that p27kip1 is a target gene of miR-196a. Additionally, the expression of some proteins associated with cell cycle and apoptosis was tested by Western blotting assays. It was found that after overexpressing miR-196a, the proliferation of hemin-induced K562 cells was promoted while the apoptosis inhibited. Furthermore, miR-196a combines with the 3'UTR of p27kip1 directly. Additionally, the relationship between miR-196a and the protein level of p27kip1 is negative. After restoring the expression of p27kip1, the growth rate of hemin-induced K562 cells was not as high as before and the inhibition of apoptosis was alleviated. The present study validates that miR-196a overexpression inhibits apoptosis in hemin-induced K562 cells through downregulating p27kip1.
Keywords: apoptosis; cell cycle; hemin-induced K562 cells; microRNA-196a; p27kip1; proliferation.