| Objective : To detect the expression of CREPT (Cell-cycle related and expression-elevated protein in tumor) in OSCC ( Oral squamous cell carcinoma,OSCC ) tissues and normal tissues, and to analyse the effect and clinical significance of CREPT in OSCC. To study the role of CREPT in squamous cell carcinoma cell lines by transfecting SCC25 and CAL27 cell lines with CREPT shRNA. By tumorigenesis assay, to study the change of tumor growth in nude mice which injected CAL27 cells transfected with lentivirus vector carrying CREPT shRNA.It provides new clues and research targets on exploring the pathogenesis, prognosis and treatment of OSCC.Methods : Quantitative PCR, Western blot assay and immunohistochemistry were applied to detect the expression of CREPT in OSCC cell lines,OSCC tissues and normal tissues. We established cell lines named SCC25con, SCC25shCREPT,CAL27con and CAL27shCREPT by lentivirus delivering specific shRNA of CREPT to knocking down the expression of CREPT. To verify the functions of CREPT in SCC25 and CAL27 cells,we have used cell proliferation, colony formation, apoptosis,cell migration and xenograft implantation experiments.Results :Part ?: The expression of CREPT in OSCC tumor tissues1?Detection of SCC25 and CAL27 cell lines showed the high expression of CREPT's gene and protein, which was similar with the expression of MGC803. 2?In the OSCC tumor tissues, the expression of CREPT was ranging negative to strongly positive; In the normal oral mucosa tissues,the expression of CREPT was ranging negative to positive;There had significant difference between the tumor group and the normal group;The clinical statistical results showed that the positive expression of CREPT was significantly correlated with tumor size and lymph node metastasis. 3?Detection of fresh OSCC tissue showed that the expression of CREPT in tumor tissues was higher than that of in normal tissues. 4?In the OSCC,the CREPT genes might be the potential target for the gene therapy .Part ?: The effects of CREPT on the biological behavior of OSCC cell line in vitro1.Downregulation of CREPT expression could inhibit the proliferation of SCC25 and CAL27 cells; 2?Downregulation of CREPT expression could inhibit the colony formation of SCC25 and CAL27 cells; 3?Downregulation of CREPT expression could inhibit the migration ability of SCC25 and CAL27 cells; 4?Downregulation of CREPT expression could increase the level of apoptosis in SCC25 and CAL27 cells; 5?Downregulation of CREPT expression could reduce the expression of cyclin D1, c-Myc in SCC25 and CAL27 cells.Part ?: The effects of CREPT on the biological behavior of OSCC cell lines in vivo1?CAL27 mouse xenograft model confirmed that down-regulation of CREPT decreased the tumor growth in vivo, but increased the survival ratio of hosts.2?CAL27 mouse xenograft model confirmed that down-regulation of CREPT reduced the expression of CREPT?cyclin D1 and c-Myc .Conclusion : 1?The expression of CREPT is increased in tumor tissue, which is significantly correlated with tumor size and lymph node metastasis of OSCC.2?Downregulation of CREPT expression could inhibit the proliferation and migration ability while increase the apoptosis ability of SCC25 and CAL27 cells.Downregulation of CREPT expression could reduce the expression of cyclin D1and c-Myc of SCC25 and CAL27 cells.3?CAL27 mouse xenograft model confirmed that down-regulation of CREPT decreased the tumor growth in vivo and reduced the expression of CREPT?cyclin D1 and c-Myc . |
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