Role of TGF-β 1 and TGF-β Type II Receptor in Gastric Cancer

BACKGROUND: TGF-β is known as a cell growth inhibitory factor to suppress almost all cells, including the epithelial cell. Unlike normal cells, cancer cells are not affected by TGF-β growth inhibitory action and the lack of TGF-β receptor expression or mutation is being reported as its mechanism, which is rarely studied in Korea. Therefore, we investigated this study to clarify the role of TGF-β I and TGF-β II receptors in gastric cancer. METHODS : 23 cases that underwent operations for gastric cancer provided RNA collected from their carcinoma tissues and adjacent normal tissues. We investigated the level of TGF-β 1 and T β R-II mRNA expression with semi-quantitatively reverse transcription PCR and analyzed the correlation with prognostic factors, such as tumor size, depth of invasion, tumor differentiation and lymph-node metastasis. RESULTS : (1) TGF-β I and T β R-II mRNA were expressed in all carcinoma tissues and adjacent normal tissues of the 23 cases without statistical difference in the level of the expression. (2) The level of TGF-β 1 mRNA expression was higher in patients with gastric cancer invaded only at the mucosa and submucosa than in patients with gastric cancer invaded over muscular propria, and also higher in the patients without lymph-node metastasis or perineural invasion than in the patients with lymph-node metastasis or perineural invasion. There was no significant correlation between the level of T β R-II mRNA expression and several parameters, such as age, gender, tumor size, location, differentiation, Lauren’s classification and vascular invasion. (3) There was a significant correlation between the level of TGF-β 1 and T β R-II mRNA expression in carcinoma tissues. CONCLUSION : It indicated that TGF-β 1 mRNA expression in gastric cancer might concern the early stage of gastric carcinogenesis and, unlike the earlier reports, it was higher in patients with early gastric cancer, negative lymph-nodes or negative perineural invasion. Further studies are required to clarify the role of TGF-β 1 in gastric carcinogenesis with more patients.