The Influence Of CO₂ Pneumoperitoneum On The Cell Of Colon Cancer

Numerous clinical reports have raised the possibility that laparoscopic cancer surgery, in contrast to conventional surgery, has an inherently detrimental effect on tumor growth. There have been numerous reports regarding site metastases and diffuse intraperitoneal metastases after laparoscopic surgery. So what is the influence of COi pneumoperitoneum on the cancer cells became a research point. The aim of this study was to examine the effects of CO2 pneumoperitoneum and Argon(Ar) pneumoperitoneum on the cytocyle and the CD44 expression in cultured SW480 colon cancer cells to explain potential dangers and risks of laparoscopic procedure.Materials and MethodsThe SW480 colon cancer cells were provided by the Zhejiang university tumor research center. We cultured the cell by RPMI 1640 solution in a culture box containing 5% COi at 37癈. Later, we divided the cells into three 6-well culture plates. Every well has 2X106 cells.Then we divided them into three groups randomly: CO2 group, Ar group and control group. We attempted to imitate pneumoperitoneum by increasing the ambient pressure to 15 mm mercury(Hg). The cells were exposed to the gases a total of 30 minutes. Then we measure the cyto cycle and CD44 expression at 24h, 48h and 72h after the effect of pneumoperitoneum.Result and DiscussionThe cell rate of S stage was obviously decreased in the CO2 group at 48h after the effect of pneumoperitoneum 7.2% compared with 48.3% in the Ar group , 37.2% in the control group. The percentage of stage Gl cells in the CO2 group was elevated to 89%,as compared to 47.5% of the Ar group and the 53.4% of control group(p<0.01). At 72h after the effect of pneumoperitoneum in the CO2 group, the cell rate of S stage was increased to 25.7% and the cell rate of Gl stage was decreased to 64.8%. In other words: CO2 pneumoperitoneum had no effect on promoting the growth of colon cancer cells, on the contrast it has some suppressive effect. As to the CD^ expression, it was obvious suppressed in the CO2 group and the Ar group 24h after the effect of pneumoperitoneum especially in the CO2 group 1.19% compared with 1.64% in the Ar group, 13.4% in the control group(p<0.01).But it was overexpressed in the CO2 group at the time of 48,72h after the effect of pneumoperitoneumwhich increased to 20.9% and 39.7% respectively as compared to 13.4% of the control group(p<0.01). From this experiment we can conclude that COi pneumoperitoneum has some effect on the colon cancer cell metastases ability. The mechanism need to be further studied.Conclusion1. CO2 pneumoperitoneum has no effect on promoting the growth of in vitro cultured colon cancer SW480 cells.2. CO2 pneumoperitoneum has positive effect on the metastases in vitro cultured colon cancer SW480 cells .