Differential Expressed Genes And Gene Expression Profiles In Different Stages Of Carcinogenesis Of Esophageal Mucosa

In an effort to isolate genes with different expression level in esophageal cancer, we performed suppression subtractive hybridization in combination with PCR-based cDNA synthesis and reverse Northern on the cancer tissues and matched adjacent normal mucosa using 5 microgram of total RNA as starting material. Among the differentially expressed genes identified, Lipocortin I, Cystatin A, Cystatin B, Cytokeratin 13 are down regulated substantially. Also a cDNA ful-length of 866bp corresponding to a novel gene has been obtained by RACE, expression of which was observed in 11/12 adjacent normal esophageal mucosa, while the matched cancer tissues showed a drastic reduction or a complete lack of its expression. The corresponding gene is designated NMES1 (normal mucosa of esophagus specific 1). Sequence analysis of its full-length cDNA revealed a novel gene with a predicted polypeptide of 9 kD and sharing a 31 ~34% similarity with the NADH.ubiquinone oxidoreductase MLRQ subunit in mouse, bovine and human. Northern blot showed that NMES1 distributed mainly in alimentary tract, such as esophagus, stomach, small intestine, and colon. Expression in other tissues tested was only observed in placenta and lung, which is quite different from that of the members of mitochondrial respiratory chain which are always present in all tissues, with higher expression level in heart, skeletal...