title: Impact of X-linked inhibitor of apoptosis protein on survival of nasopharyngeal carcinoma patients following radiotherapy.
abstract: This study aims to investigate CNE1 and CNE2 cell proliferation and apoptosis of nasopharyngeal cancer (NPC) and X-linked inhibitor of apoptosis protein (XIAP) expression in NPC patients after radiotherapy. Quantitative real-time quantitative polymerase chain reaction (qRT-PCR) and Western Blot detected XIAP and XIAP-associated factor1 (XAF1) messenger RNA (mRNA) and protein expression of CNE1 and CNE2 in NPC cells irradiated by γ-ray; MTT and flow cytometry assays detected CNE2 cells proliferation and apoptotic rate, respectively. With a retrospective analysis of 109 NPC patients in Xinxiang Central Hospital, immunohistochemistry (IHC) method detected XIAP expression, followed by a 5-year clinical analysis of the prognosis relevance after radiotherapy. In vitro, the inhibition and apoptotic rates of cells increased with the growth of radiation dose. qRT-PCR and Western blot detection declared that XIAP mRNA and protein expression increased, whereas XAF1 mRNA and protein expression decreased with the growth of radiation dose and exposure time. And XIAP mRNA and protein expression were negatively correlated with proliferation and apoptotic rates of the cells. In vivo, positive XIAP expression rate was negatively correlated with pathological tumor-node-metastasis (p-TNM) staging and tumor differentiation. Further, high XIAP expression, high p-TNM staging, and lower degree of differentiation were significantly correlated with the decrease of NPC patients' survival rate. Additionally, XIAP expression, p-TNM staging, and degrees of differentiation were independent risk factors for the survival of the NPC patients after radiotherapy. Increased XIAP expression and decreased XAF1 expression may be one reason for the apoptosis delays of CNE1 and CNE2 cells after irradiation, and the XIAP expression or the p-TNM staging and degree of differentiation are independent risk factors for NPC patients' survival after radiotherapy, providing a molecular rationale for radiotherapy and prognosis of NPC.
authors.affiliation: Department of Radiotherapy, Xinxiang Central Hospital, Weibin District, No. 56, Jinsui Road, Xinxiang, 453000, Henan Province, People's Republic of China. renminzhu1955@126.com.
authors.forename: Minzhu
authors.initials: M
authors.lastname: Ren
authors.affiliation: Department of Radiotherapy, Xinxiang Central Hospital, Weibin District, No. 56, Jinsui Road, Xinxiang, 453000, Henan Province, People's Republic of China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Radiotherapy, Xinxiang Central Hospital, Weibin District, No. 56, Jinsui Road, Xinxiang, 453000, Henan Province, People's Republic of China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Gao
authors.affiliation: Department of Radiotherapy, Xinxiang Central Hospital, Weibin District, No. 56, Jinsui Road, Xinxiang, 453000, Henan Province, People's Republic of China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Gu
authors.affiliation: Department of Radiotherapy, Xinxiang Central Hospital, Weibin District, No. 56, Jinsui Road, Xinxiang, 453000, Henan Province, People's Republic of China.
authors.forename: Liping
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Radiotherapy, Xinxiang Central Hospital, Weibin District, No. 56, Jinsui Road, Xinxiang, 453000, Henan Province, People's Republic of China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Chen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D017209:Apoptosis / Q000235:genetics / Q000528:radiation effects; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D049109:Cell Proliferation / Q000235:genetics / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000532:radiotherapy*; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D011379:Prognosis; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000235:genetics* / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D051636:X-Linked Inhibitor of Apoptosis Protein; C417551:XAF1 protein, human; C496866:XIAP protein, human
keywords: Apoptosis; CNE2 cells; IHC; NPC; Prognosis; Protein expression; XIAP; γ-ray