Mitochondrial transcription factor A(TFAM),a member of high-mobility group(HMG)protein family encoded by the nuclear genome and transported into the mitochondrial matrix,which is essential for the replication,transcription and maintenance of mitochondrial DNA(mtDNA).Interestingly,emerging evidences indicate that TFAM is involved in tumor initiation and progression of certain cancers.The role of TFAM in non-small cell lung cancer(NSCLC)remains largely unknown.Herein,we report that downregulation of TFAM in NSCLC cells resulted in cell cycle arrest at G1 phase and significantly blocked NSCLC cell growth and migration through the activation of reactive oxygen species(ROS)-induced c-Jun amino-terminal kinase(JNK)/p38 MAPK signaling and decreased cellular bioenergetics.We further found that TFAM downregulation in NSCLC cells led to increased apoptotic cell death and enhanced the sensitivity of NSCLC cells to cisplatin.Tissue microarray(TMA)data showed that elevated expression of TFAM was related to the histological grade and TNM stage of NSCLC patients.We also demonstrated that TFAM is an independent prognostic factor for overall survival of NSCLC patients.Taken together,our findings suggest that TFAM could serve as a potential diagnostic biomarker and molecular target for the treatment of NSCLC,as well as for prediction of the effectiveness of chemotherapy.