An Experimental Research Of The Influence Of CO₂ Environment On The Biological Specificity Of Human Colon Carcinoma

Objective: To observe the effect of pseudo CO₂ pneumoperitoneum environment at different pressure on the biological specificity of colon cancer cell line(LOVO) by simulating laparoscopic surgery and provide a primary evidence for the safety of CO₂ pneumoperitoneum laparoscopic surgery in diagnosis and treatment of gastrointestinal malignant tumor.Method: Human colon cancer cells were exposed to carbon dioxide at different pressure. The power of hydrogen(pH) of culture medium was determine at different time. At the same time, the cell growth and apoptosis was measured with the use of cell counting and flow cytometer method(FCM). To measured the invasive ability and motility of colon cancer cell, the expression of MMP-9 mRNA and VEGF mRNA were detected by real-time semiquantitative reverse transcription polymerase chain reaction (RT-PCR).Results: Culture media pH was decreased significantly after treated by CO₂ at immediately(P<0.05).Meanwhile, there were significantly positive and negative correlation between pH and pressure correspondently. The pH of experimental group increased gradually after departed away from because the culture medium changed. The pH had no obviously discrepancy after 72 hours(P>0.05). The result of flow cytometer analyzing the cell cycle show that CO₂ pneumoperitoneum environment obviously hold back the growth of cells. And the G1 phasre cell proportion of experiment groups was higher than control group. CO₂ insufflation affects the growth of colon carcinoma. The G1 phase of carcinoma cells were higher in experiment groups than that in control group(P<0.05). The periodontal index(PI) of carcinoma cells were different among three groups in 48 hours, 72 hours and 96 hours. There were significantly negative correlation between PI and pressure correspondently(r= -0.871, p<0.01). There was significant different in apoptotic rate between the three groups(P<0.05).Conclusion: Our data demonstrated that CO₂ as gas source in pneumoperitoneum did not play role in enhancing the tumor growth and affecting the biological features of tumor in human colon carcinoma. At the opposite, CO₂ can promote the apoptosis of colon carcinoma. So, the using of CO₂ is safe in laparoscopic surgery to gastrointestinal malignant tumor. The choice of modus operandi can not decide the prognosis of colon cancer.