Identification of differentially expressed genes in esophageal cancer through SSH in combination with high throughput reverse Northern screening

To understand the molecular mechanisms of carcinogenesis of esophagus and to isolate genes with different expression levels in esophageal cancer, suppression subtractive hybridization (SSH) was combined with PCR-based cDNA synthesis and reverse Northern on the cancer tissues and matched almost normal mucosa using 5 microgram of total RNA as starting marterial. Eight genes were found expressed differentially in esophageal cancer, in which 5 were known genes and 3 were novel ones; and 6 were down-regulated in cancer tissues, while 2 were up-regulated; 6 were of mid-high abundance and 2 were of low abundance in esophagus. The results revealed that alteration in expression level of multiple genes underlied the initiation and development of esophageal cancer. The differentially expressed genes identified in this study such asliporcotin I,cystalin A, cystatin B, cytokeratin 13 may play roles in dedifferentiation, transformation and malignant proliferation of esophageal cancer. The combination of SSH with PCR-based doublestrand cDNA synthesis and high throughput reverse Northern screening is an efficient way to isolate differentially expressed genes from microgram of total RNA.