Experimental study on targeting PI3K/AKT signal pathway by RNAi suppressing gastric adenocarcinoma SGC7901 cell invasion in vitro

Objective To observe the inhibitory effects on the invasion of gastric adenocarcinoma SGC7901 cells by small hairpin RNA targeting PIK3R1 and AKT1 in vitro. Methods The recombinant adenovirus vector plasmid expression vector which contained PIK3R1 and AKT1 shRNA was transfected into SGC7901 cells. Real time PCR and Western blot were used to detect the expression of PII~R1 and AKT1. ELESA was used to measure the change in the MMP-2 and MMP-9 expression. The invasion ability of the tumor cells was examined by Scarification, Transwell and 3-dimensional matrigel matrix tests. Resuits rAdS-A-P mediated shRNA targeting PIK3Rl,and AKT1 dramatically down-regulated their expression in SGC7901 cells. MMP-2 and MMP-9 were downregulated, and TIMP-2 was upregulated. The extracellular levels of MMP-2 and MMP-9 were decreased. Scarification test indicated that the invision ability was decreased obviously. Transwell showed that the number of cells invading through the matrigel in control, nonsense sequence, and rAdS-A-P transfection groups was 105.0 ± 4.0,102.5 ± 6.4, and 67.0 ± 3.9 respectively. In the rAdS-A-P transfection group, cells formed only small aggregates as compared with the control and nonsense sequence groups in 3-dimensional matrigel matrix growth test. Conclusion ShRNA targeting PIK3R1 ,and AKTI downregulated significantly their expression in a sequence-specific manner, and inhibited the invasion of gastric adenocarcinoma SGC7901 ceils in vitro. Key words: Gastric adenocarcinoma;  RNA interference;  Invasion;  Gene therapy