The Mechanisms Of Down-regulated Expression Of Esophageal Cancer Related Gene 1(ECRG-1) In Esophageal Cancer

Esophageal cancer is one of the most common malignant tumors whith threaten the health and life of human badly .As other malignant tumors,the development and progression of esophageal cancer is related to abnormalities of many oncogenes and tumor suppressor genes closely. On the level of DNA and chromosome, the abnormal forms of tumor suppressor gene are including intragenic point mutation, gene deletions, gene shift or replacement and aberrant promoter hypermethylation.But the loss of heterozygosity (LOH) of allele and aberrant promoter hypermethylation are acknowledged as the mainly mechanisms for gene inactivation in cancer cells and both of them are ubiquitous molecular events in human malignancies. ECRG-1 gene is a new gene which was cloned by the effective mRNA differential display technique through comparing the differential gene expression between esophageal epithelium and esophageal cancer cells from high incidence families. Previous studies have showed that ECRG-1 is expressed in normal tissue, but the expression is down-regulated or absent in 95% esophageal cancer tissues; In vitro and in vivo assays have also indicated that overexpression of ECRG-1 protein inhibits tumor cell proliferation; these results display ECRG-1 is a candidate tumor suppressor gene. However, the mechanisms of ECRG-1 gene inactive in esophageal cancer have not been reported in domestic or overseas literatures at present. In our study,we exploit the frequency of LOH and the methylation state of CpG islands in 5'flank sequence of gene in esophageal carcinoma tissue by the technique of polymerase chain reaction -Simple sequence length polymorphism(PCR-SSCP),polymerase chain reaction -Restriction fragment length polymorphisms(PCR-RFLP) and sodium bisulfite treated-PCR-sequenceing,and these findings will provide theoretic principles for...