Povezanost polimorfizama gena za glutation transferaze A1, M1, P1 i T1 sa rizikom za nastanak i progresijom karcinoma bubrežnog parenhima

Background: Cytosolic glutathione S-transferases (GSTs) might affect both the development and the progression of renal cell carcinoma (RCC) due to their dual functionality. The aim of this study was to evaluate specific role of GST gene variants (GSTA1, GSTM1, GSTT1 and GSTP1) as determinants of risk in patients with renal cell carcinoma, independently or simultaneously with recognized RCC risk factors, as well as to discern whether phenotype changes reflect genotype-associated risk. Furthermore, we evaluated the effect of GST gene variants on postoperative prognosis in RCC patients. Special attention was paid to the most frequent type of RCC, clear renal cell carcinoma (ccRCC). Methods: GST genotypes were determined in 305 RCC patients and 326 matched-controls in whom overall survival was evaluated as well. The levels of benzo(a)pyrene diolepoxide (BPDE)-DNA adducts and 8-hydroxy-2′-deoxyguanosine (8-OHdG) were determined by ELISA method. The expression of GSTM1 and GSTP1 protein level, as well as the level of regulatory (ASK1, JNK1/2) and executor (Caspase-3) apoptotic molecules in ccRCC tissue samples were analyzed by method of immuniblot. The presence of GSTM1:ASK1/ GSTP1:JNK1/2 protein:protein interactions was determined by means of immunoprecipitation. Results: Significant association between GST genotype and risk of overall RCC and ccRCC development was found for GSTM1-null and GSTP1-variant genotypes, independently (p<0.05). Furthermore, 22% of all recruited ccRCC patients were carriers of combined GSTM1-null/GSTT1-active/GSTA1-low activity/GSTP1-variant genotype, exhibiting 9.32-fold elevated ccRCC risk compared to the reference genotype combination (p=0.041). Significant association between GST genotype and ccRCC risk in smokers was found only for the GSTP1 genotype, while GSTM1-null/GSTP1-variant/GSTA1 low-activity genotype combination was present in 94% of smokers with ccRCC, increasing the risk of ccRCC up to 7.57 (p=0.026)...Uvod: Zbog uloga koje poseduju, citosolne glutation S-transferaze (GST) mogu biti značajne kako u nastanku, tako i u progresiji karcinoma bubrežnog parenhima (KBP). U ovoj studiji je ispitivana uloga pojedinih GST genskih varijanti (GSTA1, GSTM1, GSTT1 i GSTP1) u nastanku KBP, nezavisno ili udruženo sa poznatim faktorima rizika za nastanak ovog karcinoma, kao i moguća povezanost fenotipskih karakteristika tumora sa odgovarajućim genotipom. Pored toga, ispitivan je i potencijalni prognostički značaj polimorfne ekspresije GST proteina kod bolesnika sa KBP. Posebna pažnja je posvećena najučestalijem podtipu KBP, svetloćelijskom karcinomu bubrežnog parenhima (sKBP). Materijal i Metode: Polimorfizam GSTa je određivan kod 305 pacijenata sa KBP i kod 326 kontrola, uparenih po godinama i polu. Pored fenotipskih karakteristika tumora, u grupi pacijenata sa KPB je praćeno i preživljavanje. Nivoi benzo(a)piren diolepoksid (BPDE)-DNK-konjugata, kao i nivoi 8-hidroksi-2-deoksiguanozina (8-OHdG) su određivani ELISA metodom. Ekspresija GSTM1 i GSTP1 proteina, kao i ekspresija regulatornih (ASK1, JNK1/2) i egzekutornih (Caspaza 3) apoptotskih molekula u uzorcima tumorskog tkiva je analizirana metodom imunoblota. Prisustvo GSTM1:ASK1, odnosno GSTP1:JNK1/2 protein:proteinske interakcije je ispitivano metodom imunoprecipitacije. Rezultati: Uočen je značajan efekat GSTM1-nultog i GSTP1-varijantnog genotipa na rizik za nastanak KBP (p