title: A functional polymorphism in the NAD(P)H oxidase subunit CYBA is related to gene expression, enzyme activity, and outcome in non-Hodgkin lymphoma.
abstract: NAD(P)H oxidase is a major endogenous source of reactive oxygen species (ROS). ROS may not only be involved in carcinogenesis but also in efficacy of chemotherapeutic agents like doxorubicin. By a comprehensive genotyping approach covering 48 genetic polymorphisms (single-nucleotide polymorphisms) in five subunits of phagocytic NAD(P)H oxidase, we asked whether they affect gene expression, enzymatic activity, and outcome of CHO(E)P chemotherapy. A highly consistent effect was observed for the CYBA 640A>G variant. In peripheral blood granulocytes of 125 healthy volunteers, the G allele of 640A>G was associated with lower NAD(P)H oxidase activity (P = 0.006). Moreover, the G allele was associated with lower mRNA and protein expression (both P = 0.02). Of clinical importance, the outcome of patients suffering from non-Hodgkin lymphoma and treated with CHO(E)P regimen was dependent on the CYBA 640A>G polymorphism. In an exploratory study (n = 401), carriers of 640GG had an event-free survival (EFS) risk ratio of 1.95 [95% confidence interval (95% CI), 1.31-2.90; P = 0.001] compared with 640AA. In a confirmatory set (n = 477), the risk ratios were 1.53 (1.04-2.25, P = 0.03). The complete set of 878 patients showed a relative risk of 1.72 (1.30-2.26) and 1.59 (1.14-2.21) for EFS and overall survival, respectively. Further molecular-biological experiments showed lower expression and reduced stability of transcripts with the G allele in lymphoblastoid cell lines. Transfection of allele-specific plasmids into HEK293 cells elicited lower activity for the G allele in a luciferase reporter gene construct. Thus, CYBA 640A>G was shown to be a functional polymorphism with possible consequences for patients receiving CHO(E)P chemotherapy and might have further implications for other ROS-mediated modalities.
authors.affiliation: Department of Clinical Pharmacology and Department of Hematology and Oncology, Georg-August-University Göttingen, Göttingen, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Hoffmann
authors.forename: Markus A
authors.initials: MA
authors.lastname: Schirmer
authors.forename: Mladen V
authors.initials: MV
authors.lastname: Tzvetkov
authors.forename: Markus
authors.initials: M
authors.lastname: Kreuz
authors.forename: Marita
authors.initials: M
authors.lastname: Ziepert
authors.forename: Leszek
authors.initials: L
authors.lastname: Wojnowski
authors.forename: Dieter
authors.initials: D
authors.lastname: Kube
authors.forename: Michael
authors.initials: M
authors.lastname: Pfreundschuh
authors.forename: Lorenz
authors.initials: L
authors.lastname: Trümper
authors.forename: Markus
authors.initials: M
authors.lastname: Loeffler
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brockmöller
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D005260:Female; D015870:Gene Expression; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D019255:NADPH Oxidases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D011239:Prednisolone / Q000008:administration & dosage; D021122:Protein Subunits; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D021122:Protein Subunits; D012333:RNA, Messenger; D014750:Vincristine; D005047:Etoposide; D004317:Doxorubicin; D003520:Cyclophosphamide; D011239:Prednisolone; D019255:NADPH Oxidases; C086986:CYBA protein, human