雄激素剥夺条件下阻断自噬增加LNCaP细胞凋亡

Objective To investigate the change of apoptosis in LNCaP cells after inhibition of autophagic process under androgen removal conditions. Methods The autophagic level was deter-mined by using confocal microscopy and RT-PCR. The DAPI staining was used to indicate the apopto-sis of LNCaP cells after inhibition of autophagic by 3-MA. Also, Z-VAD-FMK was used to extend the apoptosis results. Results ①Androgen deprivation led to increased autophagy in LNCaP cells. LN-CaP cells cultured in complete medium(CM) presented low autophagic process with 1.9 scores. After 24 hours, the punetate GFP-LC3 structures were accumulated in the cells cultured in serum-free medi-um (SF)(2.64 scores). In contrast, the number of punctate GFP-LC3 remained at a very low level (1.85 scores), when cells were incubated with DHT in SFA(serum-free medium+DHT). Statistical analysis showed the significant difference between SF and SFA (P<0.01). Semiquantitative RT-PCR was employed to examine the mRNA expression of LC3. Indeed, cells grown in the medium without serum had a higher LC3 mRNA expression with the highest at 12 hour time point as compared with the cells grown in CM. DHT treatment reduced the level of LC3 mRNA. ②Blockage of autophagy by 3-MA increased the apoptosis of LNCaP cells. LNCaP cells in SF and SFA just presented a basal level of apoptosis, which is (3.19±1.09)% and (3.01±0.33)% , respectively. Under androgen-free con-ditions, inhibition of autophagy by 3-MA could increase apoptosis significantly(10. 90±2.91%). While Z-VAD-FMK, a pan Caspase inhibitor, was able to suppress this apoptotic process to the level of (1.16±0.52)%, which was statistically significant(P<0.01). Conclusions Androgen removal can lead to the increase of autophagy in LNCaP cells. Moreover, inhibition of autophagy promotes the occurrence of apoptosis.

Inhibition of autophagy leads to increased apoptosis in LNCaP cells under androgen deprivation conditions