title: Identification of the proteins related to p53-mediated radioresponse in nasopharyngeal carcinoma by proteomic analysis.
abstract: Radiotherapy is the primary treatment for nasopharyngeal cancer (NPC), and p53 is closely associated with the radiosensitivity of cancer, but the molecular mechanisms of p53-mediated radioresponse in NPC remains unclear. We previously established NPC CNE2sip53 cell line with p53 knockdown and paired control cell line CNE2/pSUPER, which provides a cell model system to investigate mechanisms of p53-mediated radioresponse in NPC. In this study, we first compared the radiosensitivity of CNE2sip53 and CNE2/pSUPER by a clonogenic survival assay, cell growth assay, and Hoechst 33258 staining and flow cytometry analysis of apoptotic cells. The results showed that the radiosensitivity of CNE2sip53 was significantly lower than that of CNE2/pSUPER, indicating that p53 plays a role in mediating NPC radiosensitivity. To search for the proteins associated with the p53-mediated radioresponse in NPC, a proteomic approach was performed to identify the radioresponsive proteins in CNE2sip53 and CNE2p/SUPER, respectively, and then the difference of radioresponsive proteins in CNE2sip53 and CNE2p/SUPER was compared. As a result, 14 differential radioresponsive proteins were identified in the two cell lines, 4 proteins of which were conformed by Western blot. Among them, 9 and 5 proteins were identified solely from CNE2p/SUPER and CNE2sip53, respectively. Furthermore, protein-protein interaction analysis showed that 7 differential radioresponsive proteins identified only in CNE2p/SUPER were related to p53 protein. Our results suggest that the differential radioresponsive proteins unique to CNE2p/SUPER may be involved in p53-mediated radioresponse in NPC, which will be helpful for elucidating the mechanisms of p53-mediated NPC cellular response to radiotherapy.
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha 410008, China.
authors.forename: Gu-Qing
authors.initials: GQ
authors.lastname: Zeng
authors.forename: Hong
authors.initials: H
authors.lastname: Yi
authors.forename: Xin-Hui
authors.initials: XH
authors.lastname: Li
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Shi
authors.forename: Cui
authors.initials: C
authors.lastname: Li
authors.forename: Mao-Yu
authors.initials: MY
authors.lastname: Li
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Zhang
authors.forename: Xue-Ping
authors.initials: XP
authors.lastname: Feng
authors.forename: Xun-Xun
authors.initials: XX
authors.lastname: Wan
authors.forename: Jia-Quan
authors.initials: JQ
authors.lastname: Qu
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.forename: Zhu-Chu
authors.initials: ZC
authors.lastname: Chen
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Xiao
mesh_terms: D045744:Cell Line, Tumor; D005720:Gamma Rays; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects*; D055785:Gene Knockdown Techniques; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000532:radiotherapy*; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D040901:Proteomics / Q000379:methods*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D009363:Neoplasm Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53