In Vitro Study Of Antitumor Function Of Hyperthermic CO₂Pneumoperitoneum On Human Gastric Cancer Cells

Objective To in vitro observe the function of hyperthermic CO2pneumoper itoneumum (HT-CO2) on human gastric cancer SGC-7901cells, and then further investigate the feasibility of inflating hyperthermic CO2in gastric can cer patients when performing laparoscopic operation to inhibit peritoneal care inomatosis and port site metastasis.Methods Based on a newly desived in vitro experimental model, which includes:CO2cylinder, heater and pneumoperitoneum box, worked as follows:the release of CO2gas from the cylinder into the heater, which heated to a preset temperature (42℃,43℃), injected adjacent to the pneumoperitoneum box with the components of thermal and pressure receptors(the walls of the box is first heated to37to simulate the human abdominal wall).By regulating the flow of CO2gas to control the pneumoperitoneum pressure13mmHg, and remains constant,then the logarithmic phase of human gastric cancer SGC-7901cells were exposed to HT-CO2at42℃43℃for1-3h. After dealing, the cytotoxicity was detected by WST-8assay,and the death mechanism was assessed by Annexin V-FITC/PI flow cytometry, Hoechst33342/PI fluorescent microscopy,and also the apoptosis-related gene mRNA expression of Bax and bcl-2by real time fluorescent quantitative PCR.Results Cytotoxicity detection showed that HT-CO2could significantly inhibit proliferation of gastric cancer cells(P<0.05), HT-CO2(43℃,3h) leaded to a decrease to(65.83■2.40)%in viable cells. Apoptosis detection and morphological analysis showed that HT-CO2could significantly induce apoptosis of gastric cancer cells in a temperature and time dependent way. Meanwhile,it was found that HT-CO2(43℃,3h) enhance the mRNA expression of Bax(P<0.05), however, the mRNA expression level of bcl-2had no statistical difference by real time fluorescent quantitative PCR.Conclusion HT-CO2exerts a significant antitumor effect on gastric cancer cells through inducing apoptosis,and the mechanism involves the increase of the expression of Bax. It has the potential to prevent peritoneal metastasis and the port-site metastasis during laparoscopic gastric cancer surgery. Further investigations in vivo using animal experiments to explore the impact and mechanisms are now urgently needed.