Effect Of RASSF1A Gene On Phosphorylation Of Jnk In Human Gastric Caner Cells

Objective:This study is aimed to investigate the effect of RASSF1 A gene on JNK phosphorylation level in human gastric carcinoma cell line MGC-803 and SGC-7901, To investigate the regulation of RASSF1 A on JNK signaling pathway in the carcinogenesis and development of gastric carcinoma。Methods:1.Two gastric carcinoma lines(MGC-803 and SGC-7901) with different degrees of differentiation were cultured in vitro; after the RASSF1 A gene was transfected into human gastric carcinoma cells by stable transfection, Western Blotting was used to detect the expression of RASSF1 A gene before and after transfection to check the transfection effect; Western Blotting was used to detect the JNK phosphorylation level in human gastric carcinoma cells before and after transfection of RASSF1 A gene.2.Subcutaneous tumorigenicity models of gastric carcinoma cells in the group with stable transfection and high expression of RASSF1 Agene, the non-transfected group and the group transfected with empty plasmid(the control group) were respectively established in nude mice;tumor tissues were extracted 4-6 weeks later and western blotting was used to detect the phosphorylation level of JNK.Results:1. After human gastric carcinoma MGC-803 and SGC-7901 cells were stably transfected with RASSF1 A gene, Western Blotting was used for detection, finding that compared to the non-transfected group and the group transfected with the pcDNA3.1(+) empty plasmid, the group transfected with pcDNA3.1(+)-RASSF1 A plasmid had high expressions of RASSF1 A protein, with significant statistical difference(P <0.05);it prompted that RASSF1 A gene was successfully transfected to human gastric carcinoma MGC-803 and SGC-7901 cells, and human gastric carcinoma MGC-803 and SGC-7901 cell lines with stable and high Expression of RASS F1 A gene we successfully established; Results of western blotting showed that: Before and after stable transfection of human gastric carcinoma MGC-803 cells, comparisons among the group transfected with the pcDNA3.1(+)-RASSF1 A plasmid, the non-transfected group and the group transfected with the pcDNA3.1(+)empty plasmid showed that there was significant downward trend in expressions of P-JNK and JNK in the group transfected with the pcDNA3.1(+)-RASSF1 A plasmid(P<0.05), while there was nosignificant statistical difference between the non-transfected group and the group transfected with the pcDNA3.1(+) empty plasmid(P>0.05).2. Via nude mouse tumorigenicity assay, subcutaneous tumorigenicity models of gastric carcinoma cells( MGC-803 and SGC-7901) with stable and high expression and those with different degrees of differentiation in the non-transfected group and the group transfected with the pcDNA3.1(+) empty plasmid were established in nude mice and growth of the subcutaneous tumors was observed; tumor tissues were extracted 4-6 weeks later and western blotting was used to detect the phosphorylation level of JNK; western blotting results showed that compared to the non-transfected group and the group transfected with the pcDNA3.1(+) empty plasmid, tumor tissues in nude mouse models of cells in the group transfected with the pcDNA3.1(+)-RASSF1 A plasmid(gastric carcinoma cells with stable and high expression) had downward trend in expressions of P-JNK and JNK(P<0.05), while there was no significant statistical difference between the non-transfected group and the group transfected with the pcDNA3.1(+) empty plasmid(P>0.05); all the above-mentioned findings prompted that the expression of P-JNK of gastric carcinoma MGC-803 and SGC-7901 cells could be regulated by the RASSF1 A gene.Conclusion:RASSF1A gene could inhibit the expression of phosphorylation of JNK in human gastric carcinoma MGC-803 and SGC-7901 cells.