Effect of cysteine-rich protein 61 on proliferation and cell cycle in human renal tubular epithelial cells

Objective To investigate the effect of cysteine-rich protein 61 (Cyr61) on proliferation and cell cycle in human renal tubular epithelial cells (HK-2). Methods Cyr61 cDNA was cloned into pEGFP-N2, then HK-2 cells were transfected with the recombinant plasmid pEGFP-N2-Cyr61 by Lipofectamine. The cell proliferation was measured by MTT. The expression level of Cyr61, p-FAK and cyclin dependent cyclin-dependent kinase 2 (CDK2) protein were detected by Western blotting. The cell cycle and cell apoptosis were analyzed by flow cytometry. Results The recombinant plasmid pEGFP-N2-Cyr61 could be transfected into HK-2 efficiently. After transfection, the proliferative activity was significantly increased, the proportion of HK-2 cells in G1 phase decreased and in S-phase increased significantly, the level of cell apoptosis decreased markedly (all P＜0.01). The expressions of Cyr61, p-FAK and CDK2 in Cyr61-transfected group were all amplified significantly (all P＜0.01). Conclusions Cyr61 protein over-expressed in HK-2 cells can increase CDK2 expression throngh FAK pathway, resulting in the promotion of HK-2 cells entering into S phase, cell proliferation and the reduction of cell apoptosis.