RESUMEN
Objective To investigate the mechanisms of Mal gene down regulated in human esophageal cancer. Methods We amplified the 5′regulatory region of Mal gene in normal placenta tissue and human esophageal cancer cell lines EC9706、EC8712、EC109 by optimization the PCR methods, cloned and sequenced the PCR products and compare the sequence. Results Human esophageal cancer cell lines EC9706、EC8712、EC109 all have the 654 th of 5′regulatory region of Mal gene T to C changes, corresponding codon changed from TCC to CCC, and the amino acid which it codes changed from serine to proline; EC9706 also has the 657 th of 5′regulatory region of Mal gene T to C changes, corresponding codon changed from TGC to CGC, the amino acid which it codes changed from cysteine to arginine; EC8712 has the 139 th of 5′regulatory region of Mal gene A to G changed, corresponding codon changed from GGA to GGG, the amino acid which it codes remains glycine. Conclusion Our results suggested there are may point mutation in 5′ region of Mal gene in human esophageal cancer.