Objective To study whether carbon dioxide used to establish pneumoperitoneum has an influence on port-site and intraperitoneal implantation and metastasis of tumor cells. Methods R15 hepatic cancer cells were injected into 30 Wistar rats’ peritoneal cavities 1 hour before operation, then the 30 Wistar rats were randomly divided into 3 groups: gasless group, helium group and carbon dioxide group. The suspension was exposed to the gas environment for 2 hours, all animals were killed after 28 days and the port-site and intraperitoneal implantation and metastasis of tumor cells were examined. Results On port-site, intestinal serous coat, mesentery, greater omentum and diaphragm, the weights of tumor cells, in carbon dioxide group were (326.7±230.3) mg， （626.2±215.9） mg，（476.2±204.8） mg，（2 536.5±906.7） mg and （384.5±149.9） mg respectively； in helium group were (235.6±107.3) mg， （414.2±148.4） mg, （261.8±92.6） mg, （1 633.4±247.3） mg and（220.0±57.9） mg； in gasless group were (145.0±42.4) mg， （221.5±108.2） mg， （212.5±109.6） mg, （797.5±335.9） mg and 113.0 mg.The weights of carbon dioxide group showed a significant increase, compared with helium group and gasless group (P＜0.05). The weights of helium group were greater than gasless group，but there was no significance in statistics (Pgt;0.05). Conclusion The insufflation of carbon dioxide promotes intraperitoneal tumor implantation and growth compared with helium and gaslessness in a rat model.
Objective To observe the effect of RNA interference (RNAi) on HepG2 hepatic cancer cell by small interfering RNA (siRNA). Methods siRNA targeting vascular endothelial growth factor (VEGF) gene was transfected into HepG2 cells by LipofectimineTM 2000. The VEGF mRNA and protein were respectively detected by real-time quantitive PCR and Western blot, and the concentration of VEGF protein in the cell culture supertant was determined by ELISA at 48 h after culture. Results The average efficiency of siRNA transfection was (90.4±2.9)% after 6 h cell culture. The expressions of VEGF mRNA and protein in HepG2 cells could be effectively suppressed by siRNA, and the concentration of VEGF protein in the cell culture supertant was also decreased. Conclusion siRNA can knock down the expression of VEGF gene and decrease the concentration of VEGF protein in HepG2 cells.