GLDC regulates proliferation and apoptosis of ovarian cancer cells through PI3K/Akt/mTOR pathway / 国际肿瘤学杂志

ABSTRACT

Objective:To explore the mechanism of glycine dehydrogenase (GLDC) regulating the proliferation and apoptosis of ovarian cancer cells through PI3K/Akt/mTOR pathway.Methods:RNA interference method was used to silence the expression of GLDC in ovarian cancer cell lines HEY and SK-OV-3. The HEY and SK-OV-3 cells were divided into si-control group (transfected with siRNA-control), si-GLDC#1 group (trans-fected with siRNA-GLDC#1) and si-GLDC#2 group (transfected with siRNA-GLDC#2). The expression level of GLDC and the protein phosphorylation level of PI3K/Akt/mTOR were detected by Western blotting. Cell proli-feration, migration and apoptosis were detected by CCK-8 method, Transwell chamber test, cell scratch test and flow cytometry.Results:The relative expression levels of GLDC in the si-control group, si-GLDC#1 group amd si-GLDC#2 group of HEY cells were 1.00±0.01, 0.68±0.10, 0.80±0.08, and there was a statistically significant difference ( F=13.80, P=0.006). The relative expression levels of GLDC in the si-control group, si-GLDC#1 group and si-GLDC#2 group of SK-OV-3 cells were 1.02±0.01, 0.58±0.17, 0.60±0.25, and there was a statistically significant difference ( F=6.08, P=0.036). The absorbance ( A) values in the si-control group, si-GLDC#1 group and si-GLDC#2 group of HEY cells were 1.04±0.03, 0.91±0.02, 0.82±0.01 at 24 h after transfection, 1.53±0.13, 1.30±0.03, 1.29±0.07 at 48 h after transfection, 1.44±0.08, 1.25±0.01, 1.15±0.03 at 72 h after transfection, and there were statistically significant differences ( F=83.14, P<0.001; F=8.96, P=0.007; F=29.55, P<0.001). Further pairwise comparison showed that the proliferation abilities of the si-GLDC#1 and si-GLDC#2 group at 24, 48 and 72 h were significantly lower than those of the si-control group (all P<0.05). In HEY cells, the migration numbers of cells in the si-control group, si-GLDC#1 group and si-GLDC#2 group were 57.33±6.43, 27.67±5.13 and 30.67±2.31, and there was a statistically significantly difference ( F=32.88, P=0.001). The migration numbers of cells in the si-GLDC#1 group and si-GLDC#2 group were significantly lower than that in the si-control group ( P<0.001; P=0.001). Similar results were also observed in SK-OV-3 cells. In SK-OV-3 cells, the scratch healing rates in the si-control group, si-GLDC#1 group and si-GLDC#2 group were (51.27±1.59)%, (26.35±2.94)% and (26.34±7.69)%, and there was a statistically significant difference ( F=26.54, P=0.001). The scratch healing rates in the si-GLDC#1 group and si-GLDC#2 group were significantly lower than that in the si-control group (both P=0.001). In HEY cells, the apoptosis rates in the si-control group, si-GLDC#1 group and si-GLDC#2 group were (7.11±0.82)%, (10.44±1.50)%, (17.39±1.55)%, and there was a statistically significantly difference ( F=46.52, P<0.001). The apoptosis rates in the si-GLDC#1 group and si-GLDC#2 group were significantly higher than that in the si-control group ( P=0.022; P<0.001). Similar results were also observed in SK-OV-3 cells. In HEY cells, there was no significant difference in total PI3K protein in the si-control group, si-GLDC#1 group and si-GLDC#2 group ( F=0.54, P=0.631), but there were significant differences in pAkt/Akt and pmTOR/mTOR levels ( F=22.14, P=0.016; F=10.57, P=0.044). The pAkt/Akt and pmTOR/mTOR levels in the si-GLDC#1 group and si-GLDC#2 group were significantly lower than those in the si-control group ( P=0.015, P=0.008; P=0.039, P=0.023). Similar results were also observed in SK-OV-3 cells. Conclusion:In ovarian cancer cells, GLDC silencing can inhibit cell proliferation and promote apoptosis by inhibiting the PI3K/Akt/mTOR pathway.