Abstract: BACKGROUND AND AIM: To evaluate the expression of 3 different transcripts and their clinical significance in human gastric adenocarcinomas. MATERIALS AND METHODS: The mRNA expressions of RASSF1A、RASSF1B and RASSF1C were determined by RT_PCR in gastric carcinomas BGC_823 cell lines、50 specimens of gastric carcinoma and matched normal tissues and 30 gastric biopsy specimens of high_risk group and those with possible gastric carcinoma. H.pylori in the 50 of gastric carcinomas was tested by PCR technique. RESULTS: Expression of RASSF1A mRNA was abnormally low in BGC_823 cell line, loss of expression rates of RASSF1A and RASSF1B in 50 gastric carcinomas were 52％(26/50) and 22％(11/50), respectively. RASSF1C mRNA was fully expressed. RASSF1A mRNA expression loss was positively related with histological differentiation degree (P<0.05),lymph node metastasis (P<0.05) and TNM stages(P<0.05). There was no relationship between RASSF1A expression and H.pylori infection. The rate of expression loss of RASSF1A was 20％(6/30) in gastric biopsy specimens of high_risk group and patients with possible carcinoma. However, RASSF1B and RASSF1C mRNA were fully expressed in both patient groups. The expression of RASSF1B and RASSF1C mRNA showed no statistical relation with gastric carcinoma clinical pathology indexes. CONCLUSION: RASSF1A gene is related to tumor suppression in gastric carcinoma, and correlated with the clinical pathological stage and the histological differentiation. The expression of RASSF1A was lost in gastroc biopsy specimens of high_risk group and patients with possible carcinoma. So,it could be a possible marker of early gastric carcinoma.There was no relationship between RASSF1A expression and H.pylori infection. Both are thus probably independent etiological factors.

Key words: gastric neoplasmas, RASSF1 gene, helicobacter pylori, RT_RCR