title: Proteomic analysis reveals important role of 14-3-3σ in anoikis resistance of cholangiocarcinoma cells.
abstract: Cholangiocarcinoma (CCA), a high-prevalence cancer in Thailand, is highly metastatic and has high mortality rates. Anoikis resistance or the ability of cells to survive after detachment from extracellular matrix is a necessary property of metastatic cancer. Here, we report differential protein expression of an anoikis-resistant CCA cell line culture, under attachment conditions compared to nonattachment conditions, studied using 2DE coupled with protein identification by LC-MS/MS. Our data reveal the deregulation of proteins involved in stress response, cytoskeleton rearrangement, proapoptosis, cell proliferation, and glycolysis. Interestingly, 14-3-3σ (14-3-3 sigma) protein was intensely upregulated in detached CCA cells. Real-time RT-PCR analysis confirmed that only the sigma isotype was the most abundant transcript among 14-3-3 genes in CCA cells. Furthermore, silencing 14-3-3σ expression by small interfering RNA in CCA cells resulted in significantly increased percentage of cell death in detached culture. Our findings provide the first evidence showing that 14-3-3σ protein plays a crucial role in anoikis resistance of CCA cells. Therefore, 14-3-3σ might be a potential target in CCA therapy.
authors.affiliation: Applied Biological Sciences Program, Chulabhorn Graduate Institute, Bangkok, Thailand.
authors.forename: Amnart
authors.initials: A
authors.lastname: Khongmanee
authors.forename: Kriengsak
authors.initials: K
authors.lastname: Lirdprapamongkol
authors.forename: Phanthakarn
authors.initials: P
authors.lastname: Tit-oon
authors.forename: Daranee
authors.initials: D
authors.lastname: Chokchaichamnankit
authors.forename: Jisnuson
authors.initials: J
authors.lastname: Svasti
authors.forename: Chantragan
authors.initials: C
authors.lastname: Srisomsap
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism*; D023102:Anoikis / Q000235:genetics / Q000502:physiology*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D048430:Cell Shape; D018281:Cholangiocarcinoma / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D020543:Proteome / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D034741:RNA, Small Interfering
chemical_list: D048948:14-3-3 Proteins; D014408:Biomarkers, Tumor; D020543:Proteome; D034741:RNA, Small Interfering; D005095:Exoribonucleases; C413442:SFN protein, human
keywords: 14-3-3 Sigma; Anoikis resistance; Cell biology; Cholangiocarcinoma; Metastasis