title: Association of the P-glycoprotein transporter MDR1(C3435T) polymorphism with the susceptibility to renal epithelial tumors.
abstract: Except for hereditary disease, genetic factors that contribute to the development of renal epithelial tumors are unknown. There is a possibility that the MDR1 encoded plasma membrane transporter P-glycoprotein (PGP) influences the risk of development of renal neoplasms. PGP is known to be involved in uptake, binding, transport, and distribution of xenobiotics. There is evidence that the MDR1(C3435T) polymorphism drives expression and modulates disease risk. In an explorational case-control study, constitutional genotype frequencies were established at MDR1(C3435T) of 537 healthy control subjects and compared with those of 212 patients with renal epithelial tumors. There were 179 clear cell renal cell carcinoma (CCRCC) and 33 tumors collectively assigned as non-CCRCC. In a second study, genotypes of another 150 healthy control subjects and 50 patients with three non-CCRCC types (26 papillary RCC, 11 chromophobe RCC, and 13 renal oncocytic adenoma) were compared. PCR-restriction fragment length polymorphism-based analysis of constitutional DNA, and statistical analysis were applied. PGP expression was analyzed by quantitative immunohistochemistry. The explorational study showed a significant association between T allele frequency and the occurrence of tumors (P = 0.007). When tumors were histopathologically distinguished into frequent CCRCC and less frequent non-CCRCC, both patient groups contributed to this effect with a seemingly strong influence by the latter (P = 0.0419). The second study established the T allele as a risk factor especially for non-CCRCC (P = 0.0005) with the highest risk for homozygote TT allele carriers (P < 0.0001). Independently, MDR1(C3435T) genotype associated variations in PGP expression were shown in normal renal parenchyma with a 1.5-fold difference of median values (TT, 1.9; CC, 2.8; P = 0.0065). The data provide evidence for PGP to influence the susceptibility to develop renal epithelial tumors by virtue of its MDR1(C3435T) polymorphism and changes in expression. Especially T and TT carriers are at risk for developing non-CCRCC, i.e., papillary and chromophobe RCC as well as oncocytic adenomas.
authors.affiliation: Department of Urology, University Hospital Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Heidelberg, Germany. michael.siegsmund@uro.ma.uni-heidelberg.de
authors.forename: Michael
authors.initials: M
authors.lastname: Siegsmund
authors.forename: Ulrich
authors.initials: U
authors.lastname: Brinkmann
authors.forename: Elke
authors.initials: E
authors.lastname: Scháffeler
authors.forename: Gregor
authors.initials: G
authors.lastname: Weirich
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwab
authors.forename: Michel
authors.initials: M
authors.lastname: Eichelbaum
authors.forename: Peter
authors.initials: P
authors.lastname: Fritz
authors.forename: Oliver
authors.initials: O
authors.lastname: Burk
authors.forename: Jochen
authors.initials: J
authors.lastname: Decker
authors.forename: Peter
authors.initials: P
authors.lastname: Alken
authors.forename: Uwe
authors.initials: U
authors.lastname: Rothenpieler
authors.forename: Reinhold
authors.initials: R
authors.lastname: Kerb
authors.forename: Sven
authors.initials: S
authors.lastname: Hoffmeyer
authors.forename: Hiltrud
authors.initials: H
authors.lastname: Brauch
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D019450:Genes, MDR / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007680:Kidney Neoplasms / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012016:Reference Values; D044465:White People / Q000235:genetics
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1