RESUMO
Objective To investigate the effect of silencing Notch1 gene by RNA interference on the proliferation,apoptosis and Akt/mTOR signaling pathway in clear renal cell carcinoma.Methods The optimal segment targeting Notch1 gene was designed and transfected into 786-O cells by Lipofectamine TM2000.The Notch1 mRNA and protein were detected by RT-PCR and Western blot.The proliferation rate of 786-O cells was evaluated by MTT and the variation of apoptosis was measured by TUNEL.The protein expression level of apoptosis-related protein Bcl-2,caspase-3,caspase-9,and signaling pathway protein Akt,p-Akt,p-mTOR,p-P70S6K were detected by Western blott.Results Notchl mRNA and protein was markedly suppressed by the siRNA targeting Notch1.Treated with 0,40,60,80,100 and 120 nmol/L of Notch1 siRNA for 24 hours,cell proliferation rates were (98.51 ± 1.33) ％,(87.34 ± 2.26) ％,(64.72 ± 3.24)％,(57.68 ±3.32)％,(31.91 ± 1.85)％ and (19.27 ±2.73)％,and the difference was statistically significant (P ＜ 0.01).Treated with 0,40,80,and 120 nmol/L of Notchl siRNA for 24 hours,apoptosis rates were (7.6 ± 3.8) ％,(21.5 ± 4.8) ％,(32.3 ± 3.5) ％,and (46.3 ± 4.7％),the difference was statistically significant (P ＜ 0.05).Decreased expression of Akt signaling pathway proteins p-Akt,p-mTOR,p-70S6K and apoptosis-related protein Bcl-2,procaspase-3 was detected,but no change in the total protein of Akt.Conclusions Depletion of Notch1 gene could inhibit cell growth and induce apoptosis in 786-O cell line.It inhibits Akt/mTOR signaling pathway by dephosphorylated.