title: Alkaline ceramidase 2 is a novel direct target of p53 and induces autophagy and apoptosis through ROS generation.
abstract: ACER2 is a critical sphingolipid metabolizing enzyme, and has been shown to be remarkably up-regulated following various stimuli such as DNA damage. However, the transcriptional regulatory mechanism of ACER2 gene and its potential role in the regulation of autophagy remain unknown. In this study, we have for the first time identified the human ACER2 gene promoter, and found that human ACER2 transcription is directly regulated by p53 and ACER2 is implicated in the induction of autophagy as well as apoptosis. A series of luciferase reporter assay demonstrated that ACER2 major promoter is located within its first intron where the consensus p53-binding sites exist. Consistently, forced expression of p53 significantly stimulated ACER2 transcription. Notably, p53-mediated autophagy and apoptosis were markedly enhanced by ACER2. Depletion of the essential autophagy gene ATG5 revealed that ACER2-induced autophagy facilitates its effect on apoptosis. Further studies clearly showed that ACER2-mediated autophagy and apoptosis are accompanied by ROS generation. In summary, our present study strongly suggests that ACER2 plays a pivotal role in p53-induced autophagy and apoptosis, and thus might serve as a novel and attractive molecular target for cancer treatment.
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yitao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Chunxue
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yuelei
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: He
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ai
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Lei
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Fangzhou
authors.initials: F
authors.lastname: Song
authors.affiliation: Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.|Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Youquan
authors.initials: Y
authors.lastname: Bu
mesh_terms: D000072283:A549 Cells; D055574:Alkaline Ceramidase / Q000235:genetics*; D017209:Apoptosis / Q000235:genetics; D001343:Autophagy / Q000235:genetics; D000071187:Autophagy-Related Protein 5 / Q000235:genetics*; D004249:DNA Damage / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: C502778:ATG5 protein, human; D000071187:Autophagy-Related Protein 5; D017382:Reactive Oxygen Species; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C526755:ACER2 protein, human; D055574:Alkaline Ceramidase