title: Frequent amplification of ORAOV1 gene in esophageal squamous cell cancer promotes an aggressive phenotype via proline metabolism and ROS production.
abstract: Chromosomal band 11q13 seems to be one of the most frequently amplified lesions in human cancer, including esophageal squamous cell cancer (ESCC). The oral cancer overexpressed 1 (ORAOV1) gene has been identified within this region, but its detailed biological function in human ESCC remains largely unclear. In our clinical samples of stage III ESCC, ORAOV1 amplification was observed in 49 of 94 cases (53%). ORAOV1 amplification was significantly associated with a poorly differentiated histology and tumors located in the upper or middle esophagus. Patients with ORAOV1 amplification tended to have a shorter survival period, although the difference was not significant. To investigate the function of ORAOV1, we created ORAOV1--overexpressed ESCC cell lines that exhibited increased cellular proliferation and colony formation, compared with in vitro controls. In vivo, ORAOV1-overexpressed cells exhibited a significantly increased tumorigenicity and a significantly larger tumor volume and poorer differentiation than controls. The peptide mass fingerprinting technique demonstrated that ORAOV1 bound to pyrroline-5-carboxylate reductase (PYCR), which is associated with proline metabolism and reactive oxygen species (ROS) production. Then, ORAOV1-overexpressed cell lines were resistant to stress treatment, which was cancelled by PYCR-knockdown. In addition, the ORAOV1-overexpressed cell line had a higher intracellular proline concentration and a lower ROS level. Our findings indicate that the ORAOV1 gene is frequently amplified in ESCC, enhances tumorigenicity and tumor growth, and is associated with a poorly differentiated tumor histology via proline metabolism and ROS production. ORAOV1 could be a novel target for the treatment of ESCC.
authors.affiliation: Department of Genome Biology, Kinki University Faculty of Medicine, Osaka-Sayama, Osaka, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Togashi
authors.forename: Tokuzo
authors.initials: T
authors.lastname: Arao
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kato
authors.forename: Kazuko
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Masato
authors.initials: M
authors.lastname: Terashima
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Hayashi
authors.forename: Marco A
authors.initials: MA
authors.lastname: de Velasco
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Fujita
authors.forename: Hideharu
authors.initials: H
authors.lastname: Kimura
authors.forename: Takushi
authors.initials: T
authors.lastname: Yasuda
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shiozaki
authors.forename: Kazuto
authors.initials: K
authors.lastname: Nishio
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002465:Cell Movement; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D005784:Gene Amplification; D018628:Gene Dosage; D064593:Heterografts; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D053208:Kaplan-Meier Estimate; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000235:genetics*; D010641:Phenotype; D011392:Proline / Q000378:metabolism*; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: C465628:LTO1 protein, human; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D011392:Proline