Abstract: AIM: To investigate the effect of varying pneumoperitoneum carbon dioxide pressures on adhesive and invasive capacity of gastric cancer cells.METHODS: With an artificial CO₂ pneumoperitoneum model vitalize in vitro, human gastric cancer cell line (SGC-7901) was exposed to CO₂ at different pressures for 3 h in each case:6 mm Hg(1 mm Hg=0.133 kPa),9 mm Hg,12 mm Hg , 15 mm Hg and under conventional cell culture conditions. The expressions of mRNA of E-cadherin,ICAM-1,MMP-2 and CD44v6 were measured by Real-time PCR.The expressions of protein of E-cadherin,ICAM-1,MMP-2 and CD44v6 were measured by WB.RESULTS: With the increase in pressure,RT-PCR showed that there was a downward trend in the expression of E-cadherin mRNA while there were upward trends in the expressions of ICAM-1,MMP-2 and CD44v6 mRNA.Western-blot analysis showed that the expression level of protein was consistent with the result of genetic testing.When the pressure was 15 mm Hg,the expressions of CD44v6, MMP-2 and E-cadherin had significant difference compared with the control group (P<0.05).CONCLUSION: When the pressure is not higher than 12 mm Hg , the adhesive and invasive capacity of SGC-7901 are not affected, indicating that pneumoperitoneal CO₂ pressure may not increase tumor metastasis.

Key words: gastric cancer, CO₂ pneumoperitoneum, adhesive molecule, invasive molecule, tumor metastasis