title: SPATA4 Counteracts Etoposide-Induced Apoptosis via Modulating Bcl-2 Family Proteins in HeLa Cells.
abstract: Spermatogenesis associated 4 (SPATA4) is a testis-specific gene first cloned by our laboratory, and plays an important role in maintaining the physiological function of germ cells. Accumulated evidence suggests that SPATA4 might be associated with apoptosis. Here we established HeLa cells that stably expressed SPATA4 to investigate the function of SPATA4 in apoptosis. SPATA4 protected HeLa cells from etoposide-induced apoptosis through the mitochondrial apoptotic pathway, in the way that SPATA4 suppressed decrease of the mitochondrial membrane potential, the release of cytochrome c, and subsequent activation of caspase-9 and -3. We further demonstrated that SPATA4 upregulated anti-apoptotic members of Bcl-2 family proteins, Bcl-2, and downregulated the pro-apoptotic member of Bcl-2 family proteins, Bax. Knockdown of SPATA4 in HeLa/SPATA4 cells could partially rescue expression levels of bcl-2 and bax. In conclusion, SPATA4 protects HeLa cells against etoposide-induced apoptosis through the mitochondrial apoptotic pathway. Our findings provide further evidence that SPATA4 plays a role in regulating apoptosis.
authors.affiliation: MOE Key Laboratory of Protein Sciences, Department of Pharmacology, School of Medicine, Tsinghua University.
authors.forename: Junjun
authors.initials: J
authors.lastname: Jiang
authors.forename: Liyuan
authors.initials: L
authors.lastname: Li
authors.forename: Mingchao
authors.initials: M
authors.lastname: Xie
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Fuji
authors.forename: Shangfeng
authors.initials: S
authors.lastname: Liu
authors.forename: Xiaobei
authors.initials: X
authors.lastname: Yin
authors.forename: Genlin
authors.initials: G
authors.lastname: Li
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D005047:Etoposide; D006367:HeLa Cells; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D059005:Topoisomerase II Inhibitors
chemical_list: D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C457219:SPATA4 protein, human; D059005:Topoisomerase II Inhibitors; D005047:Etoposide; D045304:Cytochromes c; D053148:Caspase 3; D053453:Caspase 9