TY - JOUR
T1 - Increased risk of lung cancer associated with a functionally impaired polymorphic variant of the human DNA glycosylase NEIL2
AU - Dey, Sanjib
AU - Maiti, Amit K.
AU - Hegde, Muralidhar L.
AU - Hegde, Pavana M.
AU - Boldogh, Istvan
AU - Sarkar, Partha S.
AU - Abdel-Rahman, Sherif Z.
AU - Sarker, Altaf H.
AU - Hang, Bo
AU - Xie, Jingwu
AU - Tomkinson, Alan E.
AU - Zhou, Mian
AU - Shen, Binghui
AU - Wang, Guanghai
AU - Wu, Chen
AU - Yu, Dianke
AU - Lin, Dongxin
AU - Cardenas, Victor
AU - Hazra, Tapas K.
N1 - Funding Information:
This research was supported by USPHS grants CA102271 and ES017353 (TKH), and CA81063 (Sankar Mitra), and ES 012512 and CA92584 (AET), CA94160 (JX) and R21CA143583 (BS). We acknowledge the generous help of Drs. Chandrasekha Yallampalli for allowing us to use Fluorescent Microscope and Michael Weinfeld for giving us PNKP Ab. We thank Dr. David Konkel for critically editing this manuscript.
PY - 2012/6/1
Y1 - 2012/6/1
N2 - Human NEIL2, one of five oxidized base-specific DNA glycosylases, is unique in preferentially repairing oxidative damage in transcribed genes. Here we show that depletion of NEIL2 causes a 6-7-fold increase in spontaneous mutation frequency in the HPRT gene of the V79 Chinese hamster lung cell line. This prompted us to screen for NEIL2 variants in lung cancer patients' genomic DNA. We identified several polymorphic variants, among which R103Q and R257L were frequently observed in lung cancer patients. We then characterized these variants biochemically, and observed a modest decrease in DNA glycosylase activity relative to the wild type (WT) only with the R257L mutant protein. However, in reconstituted repair assays containing WT NEIL2 or its R257L and R103Q variants together with other DNA base excision repair (BER) proteins (PNKP, Polβ, Lig IIIα and XRCC1) or using NEIL2-FLAG immunocomplexes, an ∼5-fold decrease in repair was observed with the R257L variant compared to WT or R103Q NEIL2, apparently due to the R257L mutant's lower affinity for other repair proteins, particularly Polβ. Notably, increased endogenous DNA damage was observed in NEIL2 variant (R257L)-expressing cells relative to WT cells. Taken together, our results suggest that the decreased DNA repair capacity of the R257L variant can induce mutations that lead to lung cancer development.
AB - Human NEIL2, one of five oxidized base-specific DNA glycosylases, is unique in preferentially repairing oxidative damage in transcribed genes. Here we show that depletion of NEIL2 causes a 6-7-fold increase in spontaneous mutation frequency in the HPRT gene of the V79 Chinese hamster lung cell line. This prompted us to screen for NEIL2 variants in lung cancer patients' genomic DNA. We identified several polymorphic variants, among which R103Q and R257L were frequently observed in lung cancer patients. We then characterized these variants biochemically, and observed a modest decrease in DNA glycosylase activity relative to the wild type (WT) only with the R257L mutant protein. However, in reconstituted repair assays containing WT NEIL2 or its R257L and R103Q variants together with other DNA base excision repair (BER) proteins (PNKP, Polβ, Lig IIIα and XRCC1) or using NEIL2-FLAG immunocomplexes, an ∼5-fold decrease in repair was observed with the R257L variant compared to WT or R103Q NEIL2, apparently due to the R257L mutant's lower affinity for other repair proteins, particularly Polβ. Notably, increased endogenous DNA damage was observed in NEIL2 variant (R257L)-expressing cells relative to WT cells. Taken together, our results suggest that the decreased DNA repair capacity of the R257L variant can induce mutations that lead to lung cancer development.
KW - BER
KW - Lung cancer
KW - NEIL2
KW - SNP
UR - http://www.scopus.com/inward/record.url?scp=84861479075&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84861479075&partnerID=8YFLogxK
U2 - 10.1016/j.dnarep.2012.03.005
DO - 10.1016/j.dnarep.2012.03.005
M3 - Article
C2 - 22497777
AN - SCOPUS:84861479075
SN - 1568-7864
VL - 11
SP - 570
EP - 578
JO - DNA Repair
JF - DNA Repair
IS - 6
ER -