Studies On Proteins Dysregulated In Esophageal Squamous Cell Carcinomas

Esophageal cancer ranks the forth most prevalent malignancy in China and squamous cell carcinoma is the main prevalent type of esophageal cancer. Because of late diagnose and poor therapeutic efficacy, the five-year survival rate is lower than 10%. In the present studies, proteomic techniques were applied to analyze the dysregulated proteins in esophageal squamous cell carcinomas, which may help to find new targets for the diagnosis and therapy of esophageal tumors.Protein profiles of 39 cases of esophageal cancerous tissues and matched normal epithelia were exhibited by two-dimensional electrophoresis (2-DE). The IPG dye strips with narrow pH range were used for the first-dimension isoeletric focusing and significantly improved the effect of protein separation. The images of 2-DE gels were analyzed by ImageMaster software. 25 proteins were found dysregulated in esophageal cancer. 19 of these proteins were successfully identified by mass spectrometry, including MnSOD, Annexin II, etc.The increased MnSOD expression in esophageal carcinomas was displayed by 2-DE in 12 out of 20 cases. Western blotting were performed in eight case of esophageal cancer and showed that the MnSOD protein was up-regulated in all eight cases. RT-PCR detected the mRNA of MnSOD in 20 cases of esophageal tumors and revealed MnSOD was increased in 17 cancerous tissues. The nuclear factor kappa B (NF-kB) transcription factor enhances the expression of MnSOD by the kB site in intron 2 of MnSOD gene. Ten cases of immunohistochemistry showed that MnSOD...