title: Reduced expression of DRAM2/TMEM77 in tumor cells interferes with cell death.
abstract: Although the role of autophagy in tumorigenesis remains controversial, recent reports support the notion that inhibition of autophagy promotes tumor formation. Damage-regulated autophagy regulator (DRAM) has been identified as an effector molecule that is critical for p53-mediated apoptosis, and we investigated whether there might be other DRAM-like molecules linking autophagy and apoptosis. In this study, we cloned a novel DRAM-homologous protein, DRAM2, and showed that the expression of DRAM2 is down-regulated in ovarian tumors. DRAM2 is mainly localized in the lysosome, and co-localizes with DRAM. While expression of DRAM or DRAM2 individually did not induce cell death, co-expression of DRAM2 with DRAM significantly induced cell death, while the silencing of endogenous DRAM2 attenuated cell death, suggesting that DRAM2 is involved in cell death. Thus, we propose that reduced expression of DRAM2 may contribute to enhanced cell survival in tumor cells.
authors.affiliation: Yonsei University, Division of Biological Science and Technology, Wonju 220-100, Republic of Korea.
authors.forename: Sun-Mi
authors.initials: SM
authors.lastname: Park
authors.forename: Kwangsoo
authors.initials: K
authors.lastname: Kim
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Lee
authors.forename: Bo-Kyoung
authors.initials: BK
authors.lastname: Kim
authors.forename: Tae Jin
authors.initials: TJ
authors.lastname: Lee
authors.forename: Taegun
authors.initials: T
authors.lastname: Seo
authors.forename: Ik-Soon
authors.initials: IS
authors.lastname: Jang
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Soohyun
authors.initials: S
authors.lastname: Kim
authors.forename: Je-Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Junsoo
authors.initials: J
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis; D045744:Cell Line, Tumor; D002470:Cell Survival; D015536:Down-Regulation; D020868:Gene Silencing; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: C544299:DRAM2 protein, human; D008565:Membrane Proteins