Inhibitory effect of adenovirus-mediated short hairpin RNA targeting P85 and Akt1 on growth of human gastric adenocarcinoma cell / 中华内科杂志

ABSTRACT

Objective To construct a short hairpin RNA (shRNA) adenovirus vector targeting P85 and protein kinase B1 (PKB1/Akt1) and study its effects on the growth of SGC-7901 human gastric adenocareinoma cells. Methods P85 and Aktl shRNA expression frames were subcloned to pGSadeno adenovirus vector with homologous recombination technology to construct pGSadeno-P85 + Akt1 (rAd5-P + A) vector. After screening and amplification, the recombinant adenovirus vector was digested with PacI and transfected into SGC-7901 cells and then its titer and transfection efficiency were detected with fluorescent microscope. P85 and Akt1 mRNA protein expression was identified with real-time PCR and Western blot. The proliferative activity of tumor cells was evaluated with MTr assay and flow cytometry in vitro, rAd5-HK and rAd5-P + A mediated by adenovirus were injected into the established subcutancous SGC-7901 gastric adenocarcinoma in nude mice. During the observation period of 21 days, tumor volume was measured every 3 days to further testify the anti-tumor effect of rAd5-P + A on the SGC-7901 gastric adenocarcinoma cells and cell in situ apoptosis was detected with TUNEL assay. Results The adenovirus vector rAd5-P + A was successfully constructed and it dramatically downregulated P85 and Akt1 mRNA expression in SGC-7901 gastric adenocarcinoma cells. Compared with a control group of SGC-7901 cells and cells transfected with general adenovirus rAd5-HK as control, P85 and Akt1 protein expression 48 h and 72 h after rAd5-P + A transfection was decreased by 57.5% and 63. 7%, 67. 8% and 75.6% with statistical significance(P = 0. 005, P = 0. 003). Cell proliferative activity in rAd5-P + A transfected cells was suppressed from the second day (P <0. 001) and the decreased P85 and Akt1 expression was accompanied by 5.9% -7. 1% decrease of S phase fraction and 12. 1% - 13.7% increase of G0/G1 phase. The tumor volume of rAd5-P + A treated group was smaller than that of the control and rAd.5-HK group with statistical significance (F = 9. 871, P = 0. 025) . Moreover, rAd5-P + A could induce cell in situ apoptosis. Conclusions Adenovirus-mediated targeting P85 and Akt1 shRNA can inhibit the growth of SGC-7901 human gastric adenocarcinoma cells and this may provide a new strategy of combination gene therapy in gastric adenocarcinoma.