mTORCl和mTORC2调控前列腺癌雄激素受体和Akt磷酸化

Modulation of androgen receptor and Akt phosphorylation in prostate cancer C4-2 cells with mTORC1 and mTORC2

目的观察mTORCl和mTORC2在前列腺癌C4-2细胞中的作用。方法噻唑蓝（MTT）比色法检测转染siRNAraptor和siRNArictor后C4-2细胞增殖改变；流式细胞术（FCM）检测敲除inTORCl（raptor）和mTORC2（rictor）后C4-2细胞凋亡；Westernblot检测siRNAraptor和siRNArictor后C4-2细胞雄激素受体（AR）和Akt磷酸化表达。结果MTY显示敲除raptor生长抑制率无显著变化[（25．37±2．63）％比（27．49±2．96）％，P〉0．05]，而敲除rictor组[（25．37±2．63）％比（62．86±5．61）％，P〈0．01]显著地抑制了细胞的生长；FCM显示敲除raptor显著增加了细胞凋亡[（11．76±1．45）％比（38．23±3．71）％，P〈0．01]，而敲除rictor对C4-2细胞凋亡无显著性变化[（11．76±1．45）％比（14．25±1．68）％，P〉0．05]；Westernblot检测显示敲除mTORCl显著增加C4-2细胞AR[（0．21±0．04）％比（0．73±0．12）％，P〈0．01]和Akt磷酸化表达[（0．23±0．06）％比（0．68±0．11）％，P〈0．01]，而敲除mTORC2显著地抑制了C4-2细胞AR[（0．21±0．04）％比（0．07±0．02）％，P〈0．01]和Akt磷酸化表达[（0．23±0．06）％比（0．064-0．03）％，P〈0．01]。结论mTORC2对前列腺癌C4-2细胞的存活是必须的，mTORC2是治疗前列腺癌有希望的靶目标。

Objective To investigate the role of mTORC1 and mTORC2 in prostate cancer C4-2 cells. Methods The growth inhibition and apoptosis rate were examined by methyl thiazol tetrazolium （MTT） assay and flow cytometry （FCM） after knockouting raptor and rictor in prostate cancer C4-2 cells. The expression of androgen receptor （AR） and Akt phosphorylation after transfection of siRNA raptor and rictor was detected by Western blotting. Results The growth inhibition of C4-2 cells had no significant change after transfecting siRNA raptor [ （25.37 ± 2. 63 ） % vs （27.49 ± 2. 96） %, P 〉 0.05 ], and the apoptosis rate was markedly increased [ （ 11.76 ± 1.45 ） % vs （38. 23 ± 3.71 ） %, P 〈 0.01 ]. The inhibition of mTORC2 （rictor） markedly decreased the growth of C4-2 cells [ （ 25.37 ± 2. 63 ） % vs （ 62. 86 ± 5.61 ） % ,P 〈 0. 01 ], and the apoptosis rate had no significant change [ （ 11.76 ± 1.45 ） % vs （ 14. 25 ± 1.68）% ,P 〉0. 05]. The expression of AR [ （0. 21 ±0. 04）% vs （0. 73 ±0. 12）% ,P 〈0. 01 ] and Akt phosphorylation [ （0. 23 ± 0. 06 ） % vs （ 0. 68 ± 0. 11 ） %, P 〈 0. 01 ] were significantly increased after knocking down mTORC1 （raptor） in C4-2 cells, andt the inhibition of mTORC2 （rictor） markedly decreased the expression of AR [ （0. 21± O. 04） % vs （0. 07 ± 0. 02） % ,P 〈 O. 01 ] and Akt phosphorylation [（0.23 ±0.06）% vs （0.06 ±0.03）% ,P〈0.01]. Conclusion mTORC2 not only is required for the survival of prostate cancer, but also a promising therapic target.