Expression of Egr-1,c-fos and cyclin D1 in esophageal cancer and its precursors:An immunohistochernical and in situ hybridization study

AIM:To examine the expression of Egr-1,c-los and cyclinD1 at both transcript and protein levels in esophagealcarcinoma and to correlate the level of their expressionswith precancerous and paracancerous esophageal lesionsand esophageal carcinoma.METHODS:In situ hybridization and immunohistochemistrywere used respectively to detect the expression of mRNAand proteins of Egr-1,c-fos and cyclin D1 in 70 cases ofesophageal squamous cell carcinoma and their correspondingpara-cancerous mucosa and upper cut edge mucosa.RESULTS:In situ hybridization and immunohistochemistryshowed positive staining of all three mRNAs in the cytoplasmand those of the proteins in nuclei.Overexpression of Egr-1,c-los and cyclin D1 mRNAs and their proteins was foundin dysplasia and squamous carcinomas.The expression levelof Egr-1 and c-los was high,and cyclin D1 was low indysplasia mucosa,whereas the expression of Egr-1 wasdecreased,c-los was maintained and cydin D1 was increasedin the cancers.The expression of both c-los and cyclin D1was consistent between the mRNA and protein in theircorresponding high expression lesions.CONCLUSION:The expression of Egr-1,c-fos and cyclinD1 varies in esophageal precancerous lesions and cancertissues,suggesting an involvement of these genes in thedevelopment of esophageal carcinoma.