Prognostic and predictive influence of polymorphisms and gene expression of proteins involved in transport and metabolism of citarabine and anthracyclines and apoptosis regulation in adult acute myeloid leukemia

[Z. D. Pravdić]

68 listova

Interna medicina - Biologija tumora i oksidativna oboljenja / Internal medicine Internal medicine - Tumor biology and oxidative diseases

Uvod: Značajne razlike u odgovoru na standardnu indukcionu terapiju, zasnovanu na citarabinu i antraciklinu, u odraslih bolesnika sa akutnom mijeloidnom leukemijom (AML), delimično bi se mogle objasniti genetičkim varijabilitetom metaboličkih puteva citarabina i antraciklina, kao i poremećenoj regulaciji apoptoze. Cilj ovog istraživanja bilo je ispitivanje uticaja polimorfizama u farmakogenima SLC29A1 (engl. solute carrier family 29 member 1), DCK (gen za deoksicitidin kinazu), ABCB1 (engl. ATP binding cassette subfamily B member 1), GSTM1 i GSTT1 (geni za glutation-S transferaze M1 i T1) i ekpsresije antiapoptotskog BCL2 (engl. B-cell leukaemia 2) i proapoptotskog BAX (engl. BCL2 associated X) i gena rezistencije na lekove (ABCB1), sa jedne strane i demografksih, kliničkih, laboratorijskih i parametara vezanih za AML, sa druge strane, na ishode lečenja odraslih bolesnika sa AML. Materijal i metode. Ukupno 100 bolesnika sa AML uključeno je u studiju. Farmakogenetički polimorfizmi SLC29A1 rs9394992, DCK rs12648166, ABCB1 rs2032582 i delecije gena GSTM1 i GSTT1 određivane su metodologijom zasnovanom na PCR-u, analizom fragmenata i direktnim sekvenciranjem. U podgrupi pedesetjednog bolesnika sa AML i normalnim kariotipom (NK), analizirane su ekspresije gena BCL2, BAX i ABCB1 PCR-om. Sve analize su sprovedene na uzorcima koštane srži uzete na dijagnozi. Korišćene su metode deskriptivne i analitičke statistike. Analiza preživljavanja je sprovedena prema Kaplan-Majerovom metodu upotrebom Log-Rank testa. Rezultati. Ovo je prva farmakogenetička i farmakotranskriptomička studija odraslih bolesnika sa AML u srpskoj populaciji. Polimorfizmi u genima SLC29A1, DCK, ABCB1, GSTM1 i GSTT1 nisu uticale na ishode lečenja u našoj kohorti obolelih od AML, samostalno ili u međusobnim kombinacijama. Međutim, postizanje kompletne remisije (KR) bolesti istaklo se kao nezavisni prediktor ishoda lečenja. Analiza u podgrupi NK AML bolesnika pokazala je da je povećana ekspresija BCL2 (BCL2+) udružena sa pojavom rezistencije (p=0,024), snižena ekspresija BAX-a sa relapsom (p=0,047), dok je u analizi združenog uticaja BAX-a i BLC2, 87% bolesnika sa BAX/BCL2nizak statusom bilo primarno refraktarno (p=0.044). Povišena ekspresija ABCB1 bila je udružena sa BCL2+ statusom (p<0.001) i odsustvom mutacije FLT3-ITD (engl. fms related receptor tyrosine kinase 3 inter tandem duplication) (p=0.019). Zaključci. Polimorfizmi gena SLC29A1, DCK, ABCB1, GSTM1 i GSTT1 nisu uticali na ishode lečenja i preživljavanje, pojedinačno ili u međusobnim kombinacijama. U podgrupi NK AML bolesnika uočeni su: veća stopa rezistencije kod visoke ekspresije BCL2, veća stopa relapsa kod niske ekspresije BAX-a i češća primarna refraktarnost u onih sa BAX/BLC2nizak statusom. Postizanje KR, u multivarijantnoj analizi, istaklo se kao nezavisni i jedini prediktor preživljavanja bez bolesti i ukupnog preživljavanja u našoj grupi odraslih novodijagnostikovanih bolesnika sa AML.

Background: Remarkable differences in therapy response among acute myeloid leukaemia (AML) patients, treated with standard cytarabine-anthracycline remission induction chemotherapy, could be partly explained by the patients’ genetic variability related to metabolic paths of cytarabine and anthracyclines and dysregulation of apoptosis. The aim of this study is to evaluate the effect of polymorphisms in pharmacogenes SLC29A1 (solute carrier family 29 member 1), DCK (deoxycytidine kinase), ABCB1 (ATP binding cassette subfamily B member 1), GSTM1 and GSTT1 (glutathione-S transferases M1 and T1) and gene expression profiles of anti-apoptotic BCL2 (B-cell leukaemia 2), pro-apoptotic BAX (BCL2 associated X) and multi-drug resistance (ABCB1), as well as laboratory and AML-related parameters on clinical outcomes and survival in adult AML patients. Methods: A total of 100 AML patients were included in the study. Pharmacogenetic polymorphisms SLC29A1 rs9394992, DCK rs12648166, ABCB1 rs2032582, GSTM1 and GSTT1 gene deletions were detected by methodology based on PCR, fragment analysis and direct sequencing. In subgroup of 51 normal karyotype (NK) AML patients the expression of BCL2, BAX and ABCB1 was analysed by PCR. All of the analyses were performed form bone marrow specimens obtained at diagnosis. Descriptive, analytic and survival (using Kaplan-Meier method / Log-Rank test) statistical analysis were performed. Results: This is the first study of pharmacogenetics and pharmacotranscriptomics in adult Serbian AML population. Clinical outcomes in our cohort of AML patients were not impacted by analysed polymorphisms in SLC29A1, DCK, ABCB1, GSTM1 and GSTT1 genes, independently or in combinations. Achievement of complete remission (CR) was identified as an independent prognostic indicator of clinical outcome. Subgroup analysis of NK AML patients showed high expression of BCL2 (BCL2+) was associated with chemoresistance (p=0.024), while patients with decreased BAX expression were susceptible to relapse (p=0.047). Joint effects of the BCL2 and BAX expression revealed that 87% of patients with BAX/BCL2low were chemo resistant (p=0.044). Increased ABCB1 expression corelated with BCL2+ (p<0.001) and with absence FLT3-ITD (fms related receptor tyrosine kinase 3 inter tandem duplication) mutations (p=0.019). Conclusions: polymorphisms of SLC29A1, DCK, ABCB1, GSTT1 and GSTM1 didn’t influence clinical outcomes, either independently or in combinations. Subgroup analysis of NK AML patients revealed that high BCL2 expression was related with chemoresistance while low expression of BAX with grater relapse rate. In addition, the patients with BAX/BLC2low status experienced primary refractoriness more frequently. Moreover, achievement of CR, in multivariate analysis, was independent and unique predictor of disease free and overall survival in our cohort of adult newly diagnosed AML patients.

akutna mijeloidna leukemija, citarabin, antraciklini, polimorfizmi gena, SLC29A1, DCK, ABCB1, GST, BCL2, BAX

acute myeloid leukaemia, cytarabine, anthracyclines, gene polymorphisms, SLC29A1, DCK, ABCB1, GST, BCL2, BAX

616.155.392:577.2(043.3)

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