[Expression of lung resistance-related protein gene in transitional cell carcinoma of the bladder].
OBJECTIVE
To investigate the role of lung resistance-related protein (LRP) in intrinsic multidrug resistance (MDR) of bladder cancer and detect the relationship of LRP expression with the clinical pathologic parameters.


METHODS
66 patients were studied with newly diagnosed primary bladder cancer (T(a) = 12, T(1) = 26, T(2) = 11, T(3) = 10, T(4) = 7; G(1) = 35, G(2) = 19, G(3) = 12). No patient was treated preoperatively with either radiation or chemotherapy. Reverse transcription-polymerase chain reaction (RT-PCR) was performed for measure of mRNA expression for LRP, multidrug-resistance gene 1 (MDR1), and multidrug resist nce-associated protein 1 (MRP1). Expressions of LRP, P53 and P63 proteins were examined by immunohistochemistry staining.


RESULTS
LRP mRNA had the highest expression rate (64%, 42/66) among three MDR markers in primary bladder cancers without chemotherapy and its level was significantly higher in normal bladder tissue than in TCC of bladder (t = 2.82, P < 0.01), in low grade than in high grade cancers (t = 4.14, P < 0.01), and in superficial than in invasive cancers (t = 3.58, P < 0.05). LRP mRNA expression showed no correlation with either MDR1 or MRP1, but close correlation with LRP protein level (r = 0.89, P < 0.01). LRP was associated with low-grade (r = 0.81, P < 0.01) and low-stage (r = 0.78, P < 0.05) cancers, but not with tumor suppressor P53 or P63 (P > 0.05).


CONCLUSIONS
The grade and stage-related expression pattern of LRP indicates that it may be a predictive index for intrinsic MDR in bladder cancer. Anti-cancer drugs out of the MDR spectrum of LRP may be more effective for patients with early bladder cancer.
Kong
Chui-ze
CZ
Department of Urology, the First Affiliated Hospital of China Medical University, Shenyang 110001, China. urokong@hotmail.com
Zhu
Yu-yan
YY
Ma
Zhi-yong
ZY
Liu
Dong-hui
DH
Zeng
Yu
Y
Li
Ze-liang
ZL
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics; D000328:Adult; D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis / Q000235:genetics; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020394:Vault Ribonucleoprotein Particles / Q000096:biosynthesis / Q000235:genetics; D000099187:Major Vault Protein
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein