Cloning and sequence analysis of carcinoembryonic antigen promoter from human colorectal carcinoma with relative DNA fragment from normal tissues

摘要

Objective: To investigate the relationship betwhen production of carcinoembryonic antigen (CEA) in thehuman cells of different tissues and scquence variation of t CEA promoter in the cellular genomes. and evaluate po-tential application of the ets active scqucnce of CEA gene in colorectal carcinoma tissie-specific gene therapy.Methods: Nested-polymerase chain reaction (PCR) was employed to amplify the CEA promoter sequences fromthe genome of human colorectal carcinoma. normal adjacent colonic mucosa tissues. normal blood cells. placentatissues and some established cell lines of human origin. PCR-Southern bloting assay was utilized to define the reliability of the amplified sequences. The scquence variations were evaluated by means of PCR-single stranded conformation polymorphism (PCR-SSCP) and DNA sequencing. Binding effect of the amplified fragment was examinedby Band-Shift assay. Results: No scqucnce variation was found between-135bp and+69bp from the transcription-al initiation site. which was considered to be a core region of CEA promoter. There was no correlativity betweenproduction levels of CEA and sequence variations of CEA gene promoter core region. The fragment amplified either from normal tissues or from colorectal carcinoma tissues could equally bind with the nuclear extract from Lo-Vo cells. Conclusion: Differential level of CEA gene transcription in the colorectal carcinoma cells. as comparedwith normal tissues, was proved not to be related to the sequence variation of CEA promoter core region. CEApromoters, either from normal cellular genome or neoplasm cellular genome. were found suitable for colorectalcarcinoma tissue-specific gene therapy.