OBJECTIVETo investigate the cell cycle of Huh-7 cells affected by I148M polymorphism of PNPLA3 gene and the possible mechanisms.

METHODSHuh-7 cells which could respectively overexpress PNPLA3 wild type and I148M variant were cultured and Huh-7 cells with zero load plasmids were used as matched control, Flow cytometry was conducted to detect the cell cycles of these 3 type of Huh-7 cells and western blot and realtime fluorescence quantitative PCR were applied to investigate the expression of regulatory factors (Cyclin D1 and p53) of cell cycle. t-test was used in statistical analysis.

RESULTSCell cycle phase distribution was presented by the proportion of cells in each phases (%), compared with the control group, the cell cycle phase distribution (G1 phase 59.27 ± 0.15, G2/M phase 24.23 ± 0.31, S phases 16.50 ± 0.26) had no differences in wild type group (G1 phase 58.53 ± 0.35, G2/M phase 24.87 ± 0.60, S phases 16.60 ± 0.26; Probability value less than 0.05). While between variant type group and wild type group, G1 phase was significantly decreased (variant type group G phase 38.37 ± 0.21, Probability value less than 0.05), S phase and G2/M phase were increased (variant type group S phase 27.47 ± 0.35, P less than 0.05; G2/M phase 34.17 ± 0.15, P less than 0.05), respectively. compared with control group, the relative expression of P53 mRNA in variant type group was significantly upregulated (control group 1.06 ± 0.41, variant type group 6.54 ± 0.34; Probability value less than 0.05) and there was no statistical significance in wild type group (1.66 ± 0.30, P more than 0.05); Cyclin D1 expression showed no statistical significance in any of these three groups, control group 1.00 ± 0.10, wild type group 1.06 ± 0.03, variant type group, 1.11 ± 0.04; P > 0.05).

CONCLUSIONI148M polymorphism of PNPLA3 gene affects cell cycles of Huh-7 cells via up-regulatating P53.