[Expression and significance of MRP, GST-pi, Topo IIalpha, and LRP in gastric carcinoma].

BACKGROUND & OBJECTIVE: Multidrug resistance-associated protein (MRP), glutathione-S-transferase-pi(GST-pi), topoisomerase IIalpha(Topo IIalpha)and lung resistance protein (LRP) play important roles in the multidrug resistance(MDR)of tumor chemotherapy. There were few reports on combined determination of the expression of MRP, GST-pi, Topo IIalpha and LRP in gastric carcinoma. This study was designed to investigate the expression and significance of MRP, GST-pi, Topo IIalpha and LRP in gastric carcinomas.

METHODS

Immunohistochemistry SP method was used to determine the expression of MRP, GST-pi, Topo IIalpha, and LRP in 90 tumor samples from the patients with gastric carcinoma. Chi-square test and Fisher exact test were used to analyze the significance of the expression.

RESULTS

(1)The positive expression rates of MRP, GST-pi, Topo IIalpha and LRP in gastric carcinoma were 88.9%, 91.1%, 74.4%, and 87.7%, respectively. They were all significantly higher than those in normal stomach tissues (P< 0.05). (2)The expression levels of MRP, GST-pi, and LRP in well-moderated differentiation adenocarcinoma were significantly higher than those in poor differentiation adenocarcinoma. The expression of Topo IIin well-moderated differentiation adenocarcinoma was significantly lower than that in poor differentiation adenocarcinoma. There was no difference between the expression levels of them in different degree of invasion or with lymph nodes metastasis and without lymph nodes metastasis (P > 0.05). (3) There was no correlation in any two items among the expression levels of MRP,GST-pi, topo IIalpha,and LRP.

CONCLUSION

MRP, GST-pi, topo IIalpha,and LRP play important roles in the primary MDR of gastric carcinoma. The expression of them are associated with the differentiation, but are not associated with the invasion degree and lymph node metastasis.