start-ver=1.4 cd-journal=joma no-vol=62 cd-vols= no-issue=6 article-no= start-page=393 end-page=401 dt-received= dt-revised= dt-accepted= dt-pub-year=2008 dt-pub=200812 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Mechanistic Analysis of Resistance to REIC/Dkk-3-induced Apoptosis in Human Bladder Cancer Cells en-subtitle= kn-subtitle= en-abstract= kn-abstract=

We have recently shown that a new therapeutic modality using the REIC/Dkk-3 gene (Ad-REIC) is effective against various human cancers, including those of prostate, testis and breast origins. The aim of the present study was to examine the sensitivity of bladder cancers to Ad-REIC and to clarify the molecular mechanisms that determine sensitivity/resistance. We found that 2 human bladder cancer cell lines, T24 and J82, are resistant to Ad-REIC. In T24 and J82 cells, the ER stress response and activation of JNK were observed in a manner similar to that in the sensitive PC3 cells. Translocation of Bax to mitochondria occurred in PC3 cells but not in T24 and J82 cells. Bcl-2 was remarkably overexpressed in T24 and J82 compared with the expression levels in sensitive cell lines. Treatment of T24 and J82 cells with a Bcl-2 inhibitor sensitized the cells to Ad-REIC-induced apoptosis. The results indicate that some human bladder cancers are resistant to apoptosis induced by overexpression of REIC/Dkk-3, which is at least in part due to up-regulation of Bcl-2. These results provide a basis for possible use of Bcl-2 as a marker of sensitive cancers and to try to sensitize resistant cancers to Ad-REIC by down-regulation of Bcl-2.

en-copyright= kn-copyright= en-aut-name=KobayashiTomoko en-aut-sei=Kobayashi en-aut-mei=Tomoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SakaguchiMasakiyo en-aut-sei=Sakaguchi en-aut-mei=Masakiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TanimotoRyuta en-aut-sei=Tanimoto en-aut-mei=Ryuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=AbarzuaFernando en-aut-sei=Abarzua en-aut-mei=Fernando kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakaishiMikiro en-aut-sei=Takaishi en-aut-mei=Mikiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KakuHaruki en-aut-sei=Kaku en-aut-mei=Haruki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KataokaKen en-aut-sei=Kataoka en-aut-mei=Ken kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=SaikaTakashi en-aut-sei=Saika en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=NasuYasutomo en-aut-sei=Nasu en-aut-mei=Yasutomo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=MiyazakiMasahiro en-aut-sei=Miyazaki en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=KumonHiromi en-aut-sei=Kumon en-aut-mei=Hiromi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=HuhNam-ho en-aut-sei=Huh en-aut-mei=Nam-ho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= affil-num=1 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=2 en-affil= kn-affil=Department of Cell Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=3 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=4 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=5 en-affil= kn-affil=Department of Cell Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=6 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=7 en-affil= kn-affil=Department of Cell Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=8 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=9 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=10 en-affil= kn-affil=Department of Cell Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=11 en-affil= kn-affil=Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=12 en-affil= kn-affil=Department of Cell Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences en-keyword=REIC/Dkk-3 kn-keyword=REIC/Dkk-3 en-keyword=bladder cancer kn-keyword=bladder cancer en-keyword=apoptosis kn-keyword=apoptosis en-keyword=Bcl-2 kn-keyword=Bcl-2 END