Effects and mechanism of β2 adrenergic receptor in ferroptosis and autophagy induced by erastin in prostate cancer
Objective To investigate the effects and mechanism of β2 adrenergic receptors(ADRB2)in ferroptosis and autophagy induced by erastin(Era)in prostate cancer.Methods PC-3 cells were infected with lentivirus or control and set to sh-NC group(normal culture),sh-NC+Era group(10 μmol/L Era treatment for 24 h),sh-ADRB2 group(normal culture),and sh-ADRB2+Era group(10 μmol/L Era treatment for 24 h).The viability of the cells treated with Era and ferrostatin-1(Fer-1)was measured by CCK-8 assay.The cell morphology was analyzed by transmission electron microscopy.The malondialdehyde(MDA)content was measured by the Lipid Oxidation Detection Kit and the iron level by Iron Colorimetric Assay.Western blotting was used to detect the expressions of cystine-glutamate exchanger(XCT),ferritin heavy chain 1(FTH1),glutathione peroxidase 4(GPX4),p62,LC3,JNK,c-Jun,and p-c-Jun.PC-3 cells with ADRB2 knockdown were injected into nude mice to construct a xenograft model and then treated with Era.The animals were divided into sh-NC group,sh-NC+Era group,sh-ADRB2 group,and sh-ADRB2+Era group,with 4 mice in each group.The tumor volumes were recorded every other day and the final tumor weight was measured at study termination.The expressions of ADRB2,JNK,c-Jun,and p-c-Jun were detected by immunohistochemistry(IHC).Results The viability of PC-3 cells decreased after Era treatment(P<0.01)and recovered after Fer-1 treatment(P<0.01).Morphological changes of ferroptosis and autophagy were observed in Era-treated cells,and MDA and iron ion contents up-regulated(P<0.05 or P<0.01).Knockdown of ADRB2 and Era treatment further inhibited PC-3 cell viability(P<0.05),and MDA and iron ion contents up-regulated(P<0.01).The expressions of ferroptosis-related proteins FTH1,XCT,GPX4,and LC3 down-regulated(P<0.05 or P<0.05),p62 and JNK pathway-related proteins JNK,c-Jun,and p-c-Jun were up-regulated(P<0.01).After JNK inhibitor treatment,the expressions of FTH1,XCT,and LC3 increased,and p62 decreased(P<0.01).In the PC-3 xenograft model,tumor volume in sh-ADRB2+Era group was significantly smaller than those in sh-NC+Era group and sh-ADBR2 group(P<0.05 or P<0.01).IHC showed that compared with sh-NC group,ADRB2 protein expression level was down-regulated in sh-ADRB2 group(P<0.05),while JNK,c-Jun,and p-c-Jun protein expression levels were elevated(P<0.01).Compared with sh-NC+Era group,the ADRB2 protein expression level in sh-ADRB2+Era group was down-regulated,while JNK,c-Jun,and p-c-Jun protein expression levels were up-regulated(P<0.05).Conclusion ADRB2 regulated ferroptosis and autophagy induced by Era via JNK/c-Jun pathway in prostate cancer.