Expressions of CYP and GST Isoenzymes in Human Gastric Tumor and Non-Tumor Tissues

Abstract

In this study we investigated the immunohistochemical staining characteristics of cytochrome P450 1A1 (CYP1A1), CYPB1, CYP2E1 and glutathione S-transferase P1 (GSTP1), GSTT1, GSTO1, GSTK1 isoenzymes in gastric tumor and surrounding tumor free (normal) gastric tissues from 40 patients. For immunohistochemical studies, tissues were obtained from 40 patients with gastric adenocarcinoma. Tumor and non-tumoral control tissues of patients were compared according to their staining intensity. Relationships between CYP and GST isoenzyme expressions in adenocarcinoma tissues were examined by the Mann Whitney-U test, and the clinicopathological data were examined by the Spearman's Rank Correlation test. CYP1B1, GSTT1, GSTO1 and GSTK1 expressions in gastric cancer cells were significantly higher than those in gastric normal epithelial cells (p < 0.05). However, CYP1A1, CYP2E1 and GSTP1 expressions were not significantly higher in tumor epithelium than those in normal epithelium in human gastric adenocancer (p < 0.05). Among the studied CYPs and GSTs, there was not statistically significant association between the studied isoenzyme expressions and age, gender and tumor grade ( p > 0.05). In patients with gastric adenocarcinoma, CYP1B1, GSTO1, GSTT1, and GSTK1 protein expressions are higher in tumor than normal gastric tissues.