Multidrug resistance of testis cancers: the study of clinical relevance of P-glycoprotein expression.
Germ cell testicular tumors (GCTTs) are very sensitive to anticancer treatment. However some patients ultimately die of their disease due to tumor resistance. Multidrug resistance is mediated by the mdr1 gene product P-glycoprotein (P-gp) which is one important mechanism of drug resistance. This study attempted to examine the correlation between P-gp and tumor progression and to evaluate the clinical relevance of P-gp immunoreactivity in patients with GCTT. Expression of the P-glycoprotein was screened in 48 primary human GCTTs, that have not been treated with chemotherapy, using monoclonal antibody (C219) and immunoenzyme staining. Of the samples from 14 seminomatous germ cell testicular tumors (SGCT, 2 seminomas (14%), and of 34 non-seminomatous tumors (NSGCT) 18 (53%) showed high expression of P-glycoprotein. This difference proved to be significant (P = 0.006). The expression of P-gp showed a statistically significant positive correlation with cancers of advanced stages (P = 0.003) and cancers that showed resistance to chemotherapy (P = 0.0052). Detection of P-gp expression in patients with GCTTs before the application of anti-cancer treatment can be used as a useful prognostic marker to isolate patient subgroups with worse prognosis and less susceptibility to chemotherapy.
Eid
H
H
National Institute of Oncology, Budapest, Hungary.
Bodrogi
I
I
Csókay
B
B
Oláh
E
E
Bak
M
M
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D018236:Carcinoma, Embryonal / Q000188:drug therapy / Q000378:metabolism; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D018240:Endodermal Sinus Tumor / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D018239:Seminoma / Q000188:drug therapy / Q000378:metabolism; D013724:Teratoma / Q000188:drug therapy / Q000378:metabolism; D013736:Testicular Neoplasms / Q000188:drug therapy / Q000378:metabolism*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D009363:Neoplasm Proteins