ABSTRACT
Objective: To investigate the effect of RNA interference (RNAi) targeting AKT1 and PI3K P85 on the proliferation and invasion of breast carcinoma MCF-7 cells. Methods: The recombinant adenovirus expression vector, which contained short hairpin RNA (shRNA) targeting open reading frames of AKT1 and PI3K P85 (rAd5-siAKT1-siPI3K), was transfected into human breast carcinoma MCF-7 cells. AKT1 and PI3K P85 mRNA and protein expressions were detected by real-time PCR and Western blotting analysis. The expressions of PCNA, cyclinD1, and P53 were also detected by Western blotting analysis. The proliferation and apoptosis of MCF-7 cells were measured by MTT, flow cytometry and 2-dementinal and 3-dementional matrigel assay. Results: Recombinant adenovirus vector rAd5-siAKT1-siPI3K dramatically down-regulated AKT1 and PI3K P85 mRNA and protein expressions in MCF-7 cells; the downstream factors PCNA and cyclin D1 were also down-regulated, while P53 was up-regulated. Growth of MCF-7 cells was inhibited by over 50% in rAd5-siAKT1-siPI3K group as measured by MTT assay, and cell cycle was arrested in G_1/G_0 phase compared with untransfected and rAd5-siCtrl transfected groups. Cell growth on matrigel matrix showed normal cell shapes, while the cells in rAd5-siAKT1-siPI3K transfected group were detached from the matrix or grew in scattered clustering patterns, forming only small aggregates. Conclusion: shRNA targeting AKT1 and PI3K P85 can significantly down-regulate the expression of AKT1 and PI3K P85 in breast carcinoma MCF-7 cells, and inhibit the growth of MCF-7 cells in vitro.