Expression of DBC1 and SIRT1 is associated with poor prognosis of gastric carcinoma.
SIRT1 (silent mating-type information regulation 2 homologue 1) expression has been reported to predict poor survival in some cancers. We therefore investigated the expression levels of SIRT1 and its negative regulator, DBC1 (deleted in breast cancer 1), in gastric cancer patients. We evaluated immunohistochemical expression of DBC1, SIRT1, and p53 using 3-mm tumor cores from 177 gastric cancer patients for tissue microarray. Positive expressions of DBC1 and SIRT1 were seen in 62% (109 of 177) and in 73% (130 of 177) of patients, respectively. Expression of DBC1 was significantly correlated with tumor stage (P = 0.007), lymph node metastasis (P < 0.001), tumor invasion (P = 0.001), venous invasion (P = 0.001), histologic types (P < 0.001), p53 expression (P < 0.001), and SIRT1 expression (P < 0.001). SIRT1 expression was also significantly correlated with tumor stage (P < 0.001), lymph node metastasis (P < 0.001), tumor invasion (P < 0.001), histologic types (P < 0.001), and p53 expression (P = 0.001). In addition, expression of DBC1 was significantly associated with shorter overall survival and relapse-free survival by univariate analysis (P < 0.001 and P < 0.001, respectively). SIRT1 expression was also significantly associated with shorter overall survival and relapse-free survival by univariate analysis (P = 0.001 and P = 0.001, respectively). Multivariate analysis showed that tumor stage and expression of DBC1 were independent prognostic factors significantly associated with overall survival and relapse-free survival. This study shows that expression of DBC1 and SIRT1 is a significant prognostic indicator for gastric carcinoma patients.