title: Inflammation-induced protein carbonylation contributes to poor prognosis for cholangiocarcinoma.
abstract: Carbonylation is an irreversible and irreparable protein modification induced by oxidative stress. Cholangiocarcinoma (CCA) is associated with chronic inflammation caused by liver fluke infection. To investigate the relationship between protein carbonylation and CCA progression, carbonylated proteins were detected by 2D OxyBlot and identified by MALDI-TOF/TOF analyses in pooled CCA tissues in comparison to adjacent nontumor tissues and normal liver tissues. We identified 14 highly carbonylated proteins in CCA tissues. Immunoprecipitation and Western blot analyses of individual samples confirmed significantly greater carbonylation of serotransferrin, heat shock protein 70-kDa protein 1 (HSP70.1), and α1-antitrypsin (A1AT) in tumor tissues compared to normal tissues. The oxidative modification of these proteins was significantly associated with poor prognoses as determined by the Kaplan-Meier method. LC-MALDI-TOF/TOF mass spectrometry identified R50, K327, and P357 as carbonylated sites in serotransferrin, HSP70.1, and A1AT, respectively. Moreover, iron accumulation was significantly higher in CCA tissues with, compared to those without, carbonylated serotransferrin. We conclude that carbonylated serotransferrin-associated iron accumulation may induce oxidative stress via the Fenton reaction, and the carbonylation of HSP70.1 with antioxidative property and A1AT with protease inhibitory capacity may cause them to become dysfunctional, leading to CCA progression.
authors.affiliation: Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan.
authors.forename: Raynoo
authors.initials: R
authors.lastname: Thanan
authors.forename: Shinji
authors.initials: S
authors.lastname: Oikawa
authors.forename: Puangrat
authors.initials: P
authors.lastname: Yongvanit
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Hiraku
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.forename: Somchai
authors.initials: S
authors.lastname: Pinlaor
authors.forename: Chawalit
authors.initials: C
authors.lastname: Pairojkul
authors.forename: Chaisiri
authors.initials: C
authors.lastname: Wongkham
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
authors.forename: Narong
authors.initials: N
authors.lastname: Khuntikeo
authors.forename: Shosuke
authors.initials: S
authors.lastname: Kawanishi
authors.forename: Mariko
authors.initials: M
authors.lastname: Murata
mesh_terms: D001650:Bile Duct Neoplasms / Q000378:metabolism / Q000473:pathology*; D015153:Blotting, Western; D018281:Cholangiocarcinoma / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D047468:Immunoprecipitation; D007249:Inflammation / Q000378:metabolism*; D007659:Ketones / Q000378:metabolism*; D011379:Prognosis; D011506:Proteins / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007659:Ketones; D011506:Proteins