RESUMEN
Objective To investigate the effects of different CO2 pneumoperitoneum on cell cycle and cell cycle protein of a gastric cancer cell line. Methods Human gastric cancer cell line MNK-45 were exposed to 0,10,12 and 15 mm Hg CO2 pneumoperitoneum in vitro for 4 hrs. Cell cycle was measured by flowcytometry, the expression of CDK4 ,Cyclin D1、Rb and pRb was studied by Western-blot, and the binding ability of CDK4 and Cyclin D1 was evaluated by immunoprecipitation. Results The cell proliferation index in 15 mm Hg CO2 pneumoperitoneum group dropped significantly (27.4% ± 3. 7%) vs. (36. 4% ±3. 3%) ,P <0. 05, while that in other groups did not change significantly. The protein of CDK4、Cyclin D1and binding ability of Cyclin D1 and CDK4 dropped dramatically in the 15 mm Hg CO2 pneumoperitoneum group (0.71%±0.12%),(0.93% ±0.21%),(0.54%±0.11%),(0.18% ±0.02%) vs. (1.05% ±0.16%),(1.40% ±0.24%),(0.75% ±0.14%),(0.31% ±0.02%), all P<0.05. There were no changes of Rb in protein levels, while the phosphorylated Rb dropped obviously. Conclusion There was no obvious effects of clinical CO2 pneumoperitoneum on gastric cancer cells growth and proliferation.