title: Direct activation of the human major vault protein gene by DNA-damaging agents.
abstract: Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles composed of three proteins. One of the components, the major vault protein (MVP) initially named the lung resistance-related protein (LRP), was found to be overexpressed in various multidrug resistant cancer cell lines and clinical samples. In this study, we investigated whether anticancer drugs could directly induce MVP protein or gene expression in the SW-620 human colorectal cancer cell line, in which MVP has been shown to be induced by the differentiation-inducing agent, sodium butyrate (NaB). MVP protein levels were enhanced in SW-620 cells after a 72 h treatment with doxorubicin (Adr), etoposide (VP-16), cis-platinum (II) diammine dichloride (CDDP) or SN-38, but not vincristine (VCR) or paclitaxel (Taxol) at their IC50 concentration. Treatment for 48 h with Adr, VP-16 and SN-38 at their IC50 concentration also enhanced the expression of MVP mRNA. Moreover, Adr could directly enhance the transcriptional activity of MVP promoter regions. On the other hand, the Adr treatment did not affect the stability of MVP mRNA. Furthermore, MVP levels were also elevated after treatment with the DNA-damaging agents, ethidium bromide (EtBr) and ultraviolet light (UV) irradiation. Our findings therefore suggest that DNA damage enhances MVP promoter activity. Since the MVP protein and mRNA have low turnover rates, a slight enhancement of MVP promoter activity could lead to a considerable increase in the level of MVP.
authors.affiliation: Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Shimamoto
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Sumizawa
authors.forename: Misako
authors.initials: M
authors.lastname: Haraguchi
authors.forename: Takenari
authors.initials: T
authors.lastname: Gotanda
authors.forename: Hei-Cheul
authors.initials: HC
authors.lastname: Jueng
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Furukawa
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Sakata
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Akiyama
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001665:Binding Sites / Q000235:genetics; D002087:Butyrates / Q000494:pharmacology; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D015151:Immunoblotting; D000077146:Irinotecan; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D020394:Vault Ribonucleoprotein Particles / Q000235:genetics* / Q000378:metabolism; D000099187:Major Vault Protein
chemical_list: D000970:Antineoplastic Agents; D002087:Butyrates; D002166:Camptothecin; D002945:Cisplatin; D004317:Doxorubicin; D005047:Etoposide; D000077146:Irinotecan; D008156:Luciferases; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein