Suppression of Akt1 expression by small interference RNA inhibits SGC7901 cell growth in vitro and in vivo.

The Akt/PKB kinase family, including Akt1, 2 and 3, plays critical roles in regulating cell growth, proliferation, survival, metabolic and many other cellular activities. Recent evidence indicates that PKB/Akt is frequently constitutively active in many types of human cancer including gastric cancer. In the present study, we applied immunohistochemistry to tissue microarray to detect the expression of Akt1, followed by Akt1 small interference RNA (siRNA) to examine knock down of the Akt1 gene on the growth inhibition of human gastric cancer SGC7901 cells. Our results indicate that the expression of Akt1 was significantly increased in gastric cancer compared to normal gastric tissue and adjacent non-cancer tissue. The in vitro study shows that cell growth was significantly inhibited and G0/G1 arrest was observed in siRNA-Akt1-treated group. In vivo, the size of tumors was significantly smaller in SGC7901 subcutaneous mice model treated with siRNA-Akt1 than those treated with siRNA-nonsense and PBS. Our studies demonstrated siRNA-Akt1 can inhibit Akt1 expression, exerted growth inhibition effect on SGC7901 cells in vitro and in vivo. Suppression of Akt1 expression by siRNA could be a new strategy in gastric cancer treatment.