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.
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ABSTRACT: Radiotherapy is the primary treatment for nasopharyngeal carcinoma (NPC), but radioresistance remains a serious obstacle to successful treatment in many cases. Therefore, the biomarkers for predicting NPC response to radiotherapy are very important for targeted therapy and individualized radiotherapy of NPC. Accumulating evidences have shown that Annexin A1 was correlated with NPC radioresistance. First, Annexin A1 is a potential tumor suppressor gene, and can regulate tumor cell proliferation and apoptosis, thus abnormal expression of Annexin A1 in NPC affects apoptosis of tumor cells induced by ionizing radiation and radiotherapeutic efficacy. Second, Annexin A1 is one of the proteins that are involved in p53-mediated radioresponse in NPC, and it might be related to NPC radioresistance. Third, the expression level of Annexin A1 is down-regulated in NPC, and is correlated with metastasis, recurrence and poor prognosis of NPC, thus Annexin A1 downregulation may increase NPC radioresistance, leading to poor prognosis. Last but not the least, Annexin A1 is closely related with tumor chemoresistance, whereas radioresistance is similar to chemoresistance in many aspects, thus Annexin A1 may also be involved in NPC radioresistance. Based on the above mentions, we hypothesize that Annexin A1 is closely correlated with NPC radioresistance and is an important new biomarker for predicting NPC response to radiotherapy.Medical Hypotheses 05/2013; · 1.18 Impact Factor
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ABSTRACT: Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in southern China and southern Asia, and poses one of the most serious public health problems in these areas. Early diagnosis, predicting metastasis, recurrence, prognosis and therapeutic response of NPC remain a challenge. Discovery of diagnostic and predictive biomarkers is an ideal way to achieve these objectives. Proteomics has great potential in identifying cancer biomarkers. Comparative proteomics has identified a large number of potential biomarkers associated with NPC, although the clinical performance of such biomarkers needs to be further validated. In this article, we review the latest discovery and progress of biomarkers for early diagnosis, predicting metastasis, recurrence, prognosis and therapeutic response of NPC, inform the readers of the current status of proteomics-based NPC biomarker findings and suggest avenues for future work.Expert Review of Proteomics 03/2014; · 3.90 Impact Factor
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ABSTRACT: The purpose of this study was to identify miRNAs and genes involved in nasopharyngeal carcinoma (NPC) radioresistance, and explore the underlying mechanisms in the development of radioresistance. We used microarrays to compare the differences of both miRNA and mRNA expression profiles in the radioresistant NPC CNE2-IR and radiosensitive NPC CNE2 cells, applied qRT-PCR to confirm the reliability of microarray data, adopted databases prediction and anticorrelated analysis of miRNA and mRNA expression to identify the miRNA target genes, and employed bioinformatics tools to examine the functions and pathways in which miRNA target genes are involved, and construct a miRNA-target gene regulatory network. We further investigated the roles of miRNA-23a and its target gene IL-8 in the NPC radioresistance. THE MAIN FINDINGS WERE FOURFOLD: (1) fifteen differential miRNAs and 372 differential mRNAs were identified, and the reliability of microarray data was validated for randomly selected eight miRNAs and nine genes; (2) 174 miRNA target were identified, and most of their functions and regulating pathways were related to tumor therapeutic resistance; (3) a posttranscriptional regulatory network including 375 miRNA-target gene pairs was constructed, in which the ten genes were coregulated by the six miRNAs; (4) IL-8 was a direct target of miRNA-23a, the expression levels of IL-8 were elevated in the radioresistant NPC tissues and showed inverse correlation with miRNA-23a expression, and genetic upregulation of miRNA-23a and antibody neutralization of secretory IL-8 could reduce NPC cells radioresistance. We identified fifteen differential miRNAs and 372 differential mRNAs in the radioresistant NPC cells, constructed a posttranscriptional regulatory network including 375 miRNA-target gene pairs, discovered the ten target genes coregulated by the six miRNAs, and validated that downregulated miRNA-23a was involved in NPC radioresistance through directly targeting IL-8. Our data form a basis for further investigating the mechanisms of NPC radioresistance.PLoS ONE 01/2014; 9(1):e87767. · 3.73 Impact Factor