[Cloning and expression analyses of down-regulated cDNA C6-2A in human esophageal cancer].

OBJECTIVE

To clone genes associated with the genesis of human esophageal cancer.

METHODS

Identifying missing or low expressing cDNAs in human esophageal cancer tissues by mRNA differential display and examining its mRNA expression in 4 human cancer cell lines, 9 fetal tissues and other matched esophageal cancer tissues by Northern blot, dot blot and RT-PCR.

RESULTS

One cDNA fragment named C6-2A, was cloned and sequenced. There was no identical sequence with C6-2A in BLASTN database; but in querying Genbank EST, the authors found that C6-2A was identical with ne27b03.s1NCI-CGAP-C03 humans sapiens cDNA clone IMAGE:898541 3' and zv30g07.rl Soares ovary tumor NbHOT homo sapiens cDNA clone 755196. 6/6 esophageal cancer tissues in Northern blot and 7/8 in dot blot did not or slightly express C6-2A. RT-PCR analysis showed that C6-2A was expressed much lower in 17/20 esophageal cancer tissues than adjacent microscopically normal mucosa, highly expressed in fetal esophageal mucosa, skin, cerebrum, placenta; moderately expressed in fetal stomach and liver, but not detected in fetal heart, small intestine and kidney.

CONCLUSION

The high frequency of deletion of decreased expression of C6-2A in esophageal cell lines and human esophageal cancer tissues suggested that C6-2A might be involved in the carcinogenesis of esophagus.