title: Oxaliplatin induces mitotic catastrophe and apoptosis in esophageal cancer cells.
abstract: The platinum-based chemotherapeutic agent oxaliplatin displays a wide range of antitumor activities. However, the underlying molecular responses to oxaliplatin in esophageal cancer remain largely unknown. In the present study, we investigated the effect of oxaliplatin on two esophageal cancer cell lines, squamous cell carcinoma (TE3) and adenocarcinoma (TE7). Following cell-cycle arrest at G(2) phase after oxaliplatin treatment, TE3 cells died via apoptosis and TE7 cells died via mitotic catastrophe. Survivin was inhibited more in TE7 cells compared with TE3 cells, but inhibition of survivin using small interfering RNA induced mitotic catastrophe in both cell lines. Further investigations indicated that survivin promoter activity was also inhibited by oxaliplatin. Among mitotic catastrophe-associated proteins, 14-3-3 sigma was decreased in TE7 cells; no evident changes were observed for aurora kinases. Oxaliplatin-induced apoptosis in the TE3 cells was caspase dependent. However, downregulation of Bad, Bid, Puma, and Noxa, lack of cytochrome c release, and limited loss of mitochondrial membrane potential in early phase indicated possible initiation by pathways other than the mitochondrial pathway. Mechanistic studies showed that downregulation of survivin by oxaliplatin in TE7 cells was partially due to the proteasome-mediated protein degradation pathway and partially due to the downregulation of Sp1 transcription factor. Similar results were obtained for another gastric adenocarcinoma cell line, MKN45, in which survivin was previously shown to be inhibited by oxaliplatin. These data indicate that survivin may be a key target for oxaliplatin. The ability of oxaliplatin to induce different modes of cell death may contribute to its efficacy in esophageal cancer.
authors.affiliation: Department of Surgery, Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan.
authors.forename: Chew Yee
authors.initials: CY
authors.lastname: Ngan
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Akimitsu
authors.initials: A
authors.lastname: Takagi
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Fujie
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takemasa
authors.forename: Masataka
authors.initials: M
authors.lastname: Ikeda
authors.forename: Fumi
authors.initials: F
authors.lastname: Takahashi-Yanaga
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sasaguri
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Sekimoto
authors.forename: Nariaki
authors.initials: N
authors.lastname: Matsuura
authors.forename: Morito
authors.initials: M
authors.lastname: Monden
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D008938:Mitosis / Q000187:drug effects; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D009944:Organoplatinum Compounds / Q000494:pharmacology*; D000077150:Oxaliplatin; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D050796:STAT3 Transcription Factor / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism; D000077022:Survivin
chemical_list: D000970:Antineoplastic Agents; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D009944:Organoplatinum Compounds; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D016329:Sp1 Transcription Factor; D000077022:Survivin; D000077150:Oxaliplatin; D046988:Proteasome Endopeptidase Complex; D002945:Cisplatin