Expression and implication of Pgp, MRP, LRP, GST-π in bladder urothelial carcinoma

Abstract

Objective To evaluate the expression of Pgp,MRP,LRP,GST-π,their co-expression,their clinical relativity and significances in bladder urothelial carcinoma.Methods From February 2005 to November 2010,51 patients (40 males and 11 females) with bladder cancer were recruited.The mean age was 60 years (range from 36 to 83 years).All 51 patients were with bladder urothelial carcinomas.Of whom,11 cases were grade Ⅰ tumors,18 cases were grade Ⅱ tumors and 22 cases were grade Ⅲ tumors.34 cases'were multifocal tumors,17 cases were unifocal tumors.In tumor size.There were 30 cases with tumor greater than 3cm in diameter and the other 21 cases with tumor smaller than 3 cm in diameter.Pglycoprotein (Pgp),Multi-drug resistance related protein (MRP),lung resistance protein (LRP),Glutathione s-transteferase-π (GST-r) of all the ladder urothelial carcinomas were detected by immunohistochemistry SP.The relativity and significances of the 51 cases were analyzed at the same time to find out their clinical-pathological features and relationships.Results The positive expression rates of Pgp,MRP,LRP,GST-π were 70.6％ (36/51),21.6％ (11/51),84.3％ (43/51),92.2％ (47/51),respectively.Pgp protein expression rates were 67.7％ (23/34) and 76.5％ (13/17) in multifocal tumors and unifocal tumors; MRP protein expression rates were 17.7％ (6/34) and 29.4％ (5/7) in multifocal tumors and unifocal tumors; LRP protein expression rates were 85.2％ (29/34) and 88.2％ (15/17) in multifocal tumors and unifocal tumors; GST-r protein expression rates were 88.2％ (30/34) and 100.0％ (17/17)in multifocal tumors and unifocal tumors.Pgp protein expression rates were 57.1％ (12/21) and 46.7％(14/30) in tumors larger than 3cm and tumors smaller than 3cm,respectively; MRP protein expression rates were 19.1％ (4/21) and 23.3％ (7/30) in tumors larger than 3cm and tumors smaller than 3cm;LRP protein expression rates were 81.0％ (17/21) and 86.7％ (26/30) in tumors larger than 3cm and tumors smaller than 3 cm; GST-π protein expression rates were 95.2％ (20/21) and 90.0％ (27/30) in tumors larger than 3 cm and tumors smaller than 3 cm.Pgp protein expression rates were 81.8％ (9/11),61.1％ (11/18) and 72.7％ (16/22) in grade Ⅰ,grade Ⅱ and grade Ⅲ tumors; MRP protein expression rates were 36.4％ (4/11),16.7％ (3/18) and 18.2％ (4/22) in grade Ⅰ,grade Ⅱ and grade Ⅲ tumors; LRP protein expression rates were 100.0％ (11/11),88.9％ (16/18) and 72.7％ (16/22) in grade Ⅰ,grade Ⅱ and grade Ⅲ tumors; GST-π protein expression rates were 100.0％ (11/11),94.4％ (17/18) and 86.4％ (19/22) in grade Ⅰ,grade Ⅱ and grade Ⅲ tumors.LRP protein expression rates were 60.0％ (6/10) and 90.2％ (37/41) in patients of different ages (P ＜ 0.05).GST-π protein expression rates were 95.0％ (38/40) in males and 81.8％ (9/11) in females (P ＜ 0.05).The co-expression rates werePgp+MRP 13.7％ (7/51),Pgp+LRP 58.8％ (30/51),Pgp+GST-π 64.7％ (33/51),MRP+LRP 15.7％ (8/51),MRP+GST-π 15.7 ％ (8/51),LRP+GST-π 82.4％ (42/51),Pgp+MRP + LRP + GST-π 13.7％ (7/51),Pgp + LRP + GST-π 56.9％ (29/51).Significant relationships were detected between Pgp and MRP (r =0.077,P ＜ 0.05),Pgp and GST-π (r =0.097,P ＜ 0.05),MRP and LRP (r =0.065,P ＜0.05),MRP and GST-π (r =0.052,P ＜0.05),LRP and GST-π (r =0.093,P ＜ 0.05).But no statistical significance relationship between Pgp and LRP(r =0.097,P ＞ 0.05)was found.Conclusions The multi-drug resistance in bladder urothelial carcinomas is affected by various multi-drug resistance genes.The expression of LRP is related to patient's age.The expression of GST-π is related to patient's gender.No relationship is established between expression of Pgp,MRP,LRP,GST-π and tumor occurrence frequency,tumor numbers,tumor size,histological grade,clinical-pathological features. Key words: Bladder urothelial carcinoma; Multi-drug resistance associated proteins; Immunohistochemistry