Comparative proteomic study of nasopharyngeal carcinoma cell lines with different radiosensitivity / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the proteins which were associated with radiosensitivity of nasopharyngeal carcinoma (NPC) cells and could be used to predict the radiosensitivity.Methods A radioresistant subclone cell line CNE-2 (R743) derived from NPC cell line CNE-2 was established.Radiosensitivity and cell cycle characteristics of CNE-2 and CNE-2 ( R743 ) were examined and compared by clonogenic survival assay and flow cytometry.The total proteins from the two cell lines were extracted and separated by two-dimensional gel electrophoresis,and the images were analyzed by Image Master 7.0analysis software.Differentially expressed proteins in the two cell lines were identified through MALDITOF/TOF peptide mass fingerprint and searched in the protein sequence database.The protein expressions were confirmed by RT-PCR and Western blot.Results Totally seven differentially expressed proteins were identified,six of which were upregulated and one downregulated in the radioresistant CNE-2 (R743),compared with those of CNE-2.Three out of the seven,Annexin A2,Tropomyosin 4 and GRP78 were upregulated in the CNE-2 ( R743 ),which were confirmed by Western blot and RT-PCR ( t =24.22,24.20,29.19,P ＜ 0.05).Conclusions Differentially expressed proteins might be involved in different radiosensitivities of nasopharyngeal carcinoma cell lines,among which Annexin A2,Tropomyosin 4 and GRP78 could be the candidate biomarkers for predicting radiosensitivity of nasopharyngeal carcinoma cells.