FOXO3a protects glioma cells against temozolomide-induced DNA double strand breaks via promotion of BNIP3-mediated mitophagy  

作　　者：Chuan He Shan Lu Xuan-zhong Wang Chong-cheng Wang Lei Wang Shi-peng Liang Tian-fei Luo Zhen-chuan Wang Mei-hua Piao Guang-fan Chi Peng-fei Ge 

机构地区：[1]Department of Neurosurgery,First Hospital of Jilin University,Changchun 130021,China [2]Research Center of Neuroscience,First Hospital of Jilin University,Changchun 130021,China [3]Department of Neurology,First Hospital of Jilin University,Changchun 130021,China [4]Department of Anesthesiology,First hospital of Jilin University,Changchun 130021,China [5]Key Laboratory of Pathobiology,Ministry of Education,Jilin University,Changchun 130021,China

出　　处：《Acta Pharmacologica Sinica》2021年第8期1324-1337,共14页中国药理学报（英文版）

基　　金：supported by National Natural and Science Foundation of China(81772669 and 81972346);Changbaishan Scholar Project of Jilin Province(2013026);Scientific Research Foundation of Jilin Province(20190701051GH and 20200201405JC);the Achievement Transformation Fund of the First Hospital of Jilin University(JDYYZH-1902040).

摘　　要：FOXO3a(forkhead box transcription factor 3a)is involved in regulating multiple biological processes in cancer cells.BNIP3(Bcl-2/adenovirus E1B 19-kDa-interacting protein 3)is a receptor accounting for priming damaged mitochondria for autophagic removal.In this study we investigated the role of FOXO3a in regulating the sensitivity of glioma cells to temozolomide(TMZ)and its relationship with BNIP3-mediated mitophagy.We showed that TMZ dosage-dependently inhibited the viability of human U87,U251,T98G,LN18 and rat C6 glioma cells with IC_(50) values of 135.75,128.26,142.65,155.73 and 111.60μM,respectively.In U87 and U251 cells,TMZ(200μM)induced DNA double strand breaks(DSBs)and nuclear translocation of apoptosis inducing factor(AIF),which was accompanied by BNIP3-mediated mitophagy and FOXO3a accumulation in nucleus.TMZ treatment induced intracellular ROS accumulation in U87 and U251 cells via enhancing mitochondrial superoxide,which not only contributed to DNA DSBs and exacerbated mitochondrial dysfunction,but also upregulated FOXO3a expression.Knockdown of FOXO3a aggravated TMZ-induced DNA DSBs and mitochondrial damage,as well as glioma cell death.TMZ treatment not only upregulated BNIP3 and activated autophagy,but also triggered mitophagy by prompting BNIP3 translocation to mitochondria and reinforcing BNIP3 interaction with LC3BII.Inhibition of mitophagy by knocking down BNIP3 with SiRNA or blocking autophagy with 3MA or bafilomycin A1 exacerbated mitochondrial superoxide and intracellular ROS accumulation.Moreover,FOXO3a knockdown inhibited TMZ-induced BNIP3 upregulation and autophagy activation.In addition,we showed that treatment with TMZ(100 mg·kg^(-1)·d^(-1),ip)for 12 days in C6 cell xenograft mice markedly inhibited tumor growth accompanied by inducing FOXO3a upregulation,oxidative stress and BNIP3-mediated mitophagy in tumor tissues.These results demonstrate that FOXO3a attenuates temozolomide-induced DNA double strand breaks in human glioma cells via promoting BNIP3-mediated mitophagy.

关 键 词：glioma TEMOZOLOMIDE DNA double strand break oxidative stress mitochondrial superoxide BNIP3 FOXO3A MITOPHAGY 3MA bafilomycin A 

分 类 号：R285.5[医药卫生—中药学]