Impact of different pressures and exposure times of a simulated carbon dioxide pneumoperitoneum environment on proliferation and apoptosis of human ovarian cancer cell lines

Background: This study aimed too evaluate the proliferation and apoptosis of human ovarian cancer cell lines HO8910 and SKOV3 after exposure to a simulated laparoscopic carbon dioxide (CO2) pneumoperitoneum environment at different pressures and lengths of exposure time. Methods: The effects of the simulated laparoscopic CO2 pneumoperitoneum environment at different CO2 pressures (0-16 mmHg) and exposure times (1-4 h) on tumor cell growth and apoptosis were assessed by 3[4,5-Dimethylthiazol]-2; 5-diphenyttetrazolium bromide (MTT) chromometry and proliferative index (PI) staining or Annexin V and PI double-staining flow cytometry. Cells cultured in a standard environment were used as the control group. Results: In this study, HO8910 cell growth tended to slow down with the increase in CO2 pressure and exposure time. A significantly lower PI was observed at 72 h of culture after exposure to both 8 and 16 mmHg of pressure, as compared with the control and 0 mmHg pressure group (p < 0.05). The PI of SKOV3 cells tended to decline after exposure. Significantly lower PI was observed in the group with exposure to 16 mmHg for 4 h over a 72-h period, as compared with the control groups exposed to 0 mmHg (p < 0.05). The inhibition of cell growth was associated with an increase in the proportion of cells at stage G1. The apoptotic index and the percentage of apoptotic cells tended to increase with an increase in pressure and a prolonged time of exposure. Conclusions: The results suggest inhibited cell proliferation and increased cell apoptosis of human ovarian cancer cells were positively related to CO2 pressure and exposure time.