OBJECTIVE： To study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. METHODS： EC9706 cells were treated in the follow- ing six groups： blank group （n...OBJECTIVE： To study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. METHODS： EC9706 cells were treated in the follow- ing six groups： blank group （no transfection）, nega- tive control group （transfection no-carrier）, trans- fection group （transfected with pSilencer-siK-ras）, taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and west- ern blotting were used to analyze the expression of MAPK1 （mitogen-activated protein kinases 1） and cyclin D1 in response to siRNA （small interfering RNA） transfection and taxol treatment. RESULTS： K-Ras （K-Ras gene） siRNA transfection of EC9706 esophageal squamous carcinoma cells de- creased the expression of K-Ras, MAPK1 and cyclinD1 at the mRNA and protein level. Reverse tran- scription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group （P〈0.05）. Western blotting showed that 72 h after EC9706 cell trans- fection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the ex- pression levels in the transfection group were sig- nificantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as com- pared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe. CONCLUSION： Apoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-me- diated inhibition of Ras signaling, with the most ob- vious increase observed in the transfection plus tax- ol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeu- tic agent, taxol. Ras knockdown also down-regulat- ed the expression of the downstream genes, MAPKI and cyclin DI, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells.展开更多
基金Supported by the Natural Science Research Program of the Education Department of Henan Province(No.2011B320012)
文摘OBJECTIVE： To study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. METHODS： EC9706 cells were treated in the follow- ing six groups： blank group （no transfection）, nega- tive control group （transfection no-carrier）, trans- fection group （transfected with pSilencer-siK-ras）, taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and west- ern blotting were used to analyze the expression of MAPK1 （mitogen-activated protein kinases 1） and cyclin D1 in response to siRNA （small interfering RNA） transfection and taxol treatment. RESULTS： K-Ras （K-Ras gene） siRNA transfection of EC9706 esophageal squamous carcinoma cells de- creased the expression of K-Ras, MAPK1 and cyclinD1 at the mRNA and protein level. Reverse tran- scription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group （P〈0.05）. Western blotting showed that 72 h after EC9706 cell trans- fection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the ex- pression levels in the transfection group were sig- nificantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as com- pared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe. CONCLUSION： Apoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-me- diated inhibition of Ras signaling, with the most ob- vious increase observed in the transfection plus tax- ol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeu- tic agent, taxol. Ras knockdown also down-regulat- ed the expression of the downstream genes, MAPKI and cyclin DI, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells.
