Induced Apoptosis And Inhibited Capability Of Invasion And Migration For Gastric Cancer Cells By Hyperthermic CO₂

Objectives:We preliminary investigated the impact of a hyperthermic CO2pneumop eritoneum on gastric cancer cells on aspect of proliferation, apoptosis, invasive and migra te ability by cell experiment of in vitro hyperthermic CO2pneumoperitoneum circumstanc es. This could form the theoretical basis for further studies of the feasibility and safety of inflating hyperthermic CO2in the abdominal cavity of gastric cancer patients during1aparoscopy.Methods:An in vitro hyperthermic CO2pneumoperitoneum experimental model was built, which was composed of CO2steel, CO2heater and pneumoperitoneum box. Gastric cancer cell line SGC-7901cells were grouped according to temperature:control group (conventional culture in incubator), pure thermotherapy group (cultured in42℃for3h), pure CO2group (cultured in CO2environment of normal temperature for3h), hypertherm ic CO2group (cultured in CO2environment of42℃for3h). Cell proliferation was detect ed using a cell counting kit-8(CCK-8); apoptosis was detected by Annexin V-FITC/PI fl ow cytometry and Hoechst33342/PI fluorescent microscopy. Morphological alterations we re observed by transmission electron microscopy. Invasion and migration were detected b y a scratch test and by transwell migration, respectively. The experimental data was anal yzed by SPSS17.0and shown by the arithmetic mean±the standard deviation (x±s). A p value<0.05indicated a statistically significant difference.Results:CCK-8was used to detect the inhibition of cell proliferation, the results sh ow:proliferation of the pure CO2group was inhibited by11.76±7.29%, of the pure the rmotherapy group by28.08±6.77%and of the hyperthermic CO2group by38.93±7.6 3%, the differences were significant (p<0.05). Annexin V-FITC/PI flow cytometry was us ed to detect apoptosis of gastric cancer cells, the percentage of apoptotic cells in the con trol group, pure CO2group, pure thermotherapy group and hyperthermic CO2group were0.033±0.015%,2.64±0.21%,3.50±0.22%and4.91±0.20%, respectively. The differenc es were significant (p<0.05), hyperthermic CO2could significantly induce apoptosis of gas tric cancer cells. Hoechst33342/PI fluorescence microscopy was used to qualitatively obs erve apoptosis of cells, it showed that, the cells of hyperthermic CO2group of dyed brig ht blue or bright red were more than the other three groups, hyperthermic CO2induced a poptosis significantly. Transmission electron microscopy was used to observe cell morphol ogy, the cells of hyperthermic CO2group showed cytoplasmic concentration, chromatin c ondensation and margination, nuclear fragmentation, formation of apoptotic bodies, the cel1membrane and nucleus occured apoptotic morphological changes. The scratch test and t he transwell test were used to detect the impact of hyperthermic CO2on invasion and m igration, respectively, of gastric cancer cells. The results showed that cell invasion and th e number of cells passing through the microporous membrane were significantly reduced for the hyperthermic CO2group compared with control group (the more cells passing thr ough the microporous membrane, the stronger of cell migration ability). Thus, hypertherm ic CO2inhibited migration and invasion of gastric cancer cells.Conclusions:A hyperthermic CO2pneumoperitoneum could induce apoptosis and inh ibit invasion and migration ability of gastric cancer cell SGC-7901. The results provided feasibility for further research and in-depth animal studies and laid a theoretical foundatio n for the clinical application of hyperthermic CO2pneumoperitoneum.