Objective: To investigate the expression of ATP-binding cassette transporter (ABCG2) in gastric carcinoma and its clinical significance.
Methods: Expression of ABCG2 protein was examined by immunohistochemical technique in specimens from 45 gastric carcinoma tissues and 30 surrounding normal tissues. The expression of ABCG2 mRNA was measured by RT-PCR and real-time quantitative PCR in specimens from 30 gastric carcinoma tissues and 30 surrounding normal gastric mucosa respectively.
Results: ABCG2 protein expression was observed in 28 of 45 (62.2%) cases by immunohistochemical analysis, while in 2 of 30 (6.7%) normal tissues (P< 0.05). In ABCG2-positive tumors, adjacent non-neoplastic tissue was similarly analyzed and revealed that ABCG2 was up-regulated in gastric carcinoma. The positive rates of ABCG2 expression in poorly differentiated and/or undifferentiated carcinoma were significantly higher than those in well and/or moderately-differentiated carcinoma (P< 0.05). The mRNA expression of ABCG2 was significantly higher in gastric carcinoma tissue than that in normal gastric mucosa (P< 0.05).
Conclusions: ABCG2 expression is up-regulated in gastric carcinoma. ABCG2 may be an important factor in the research of gastric cancer stem cell.