Polymorphisms in DNA repair genes, hair dye use, and the risk of non-Hodgkin lymphoma
CANCER CAUSES & CONTROL
Authors: Guo, Huan; Bassig, Bryan A.; Lan, Qing; Zhu, Yong; Zhang, Yawei; Holford, Theodore R.; Leaderer, Brian; Boyle, Peter; Qin, Qin; Zhu, Cairong; Li, Ni; Rothman, Nathaniel; Zheng, Tongzhang
Abstract
Genetic polymorphisms in DNA repair genes and hair dye use may both have a role in the development of non-Hodgkin lymphoma (NHL). We aimed to examine the interaction between variants in DNA repair genes and hair dye use with risk of NHL in a population-based case-control study of Connecticut women. We examined 24 single nucleotide polymorphisms in 16 DNA repair genes among 518 NHL cases and 597 controls and evaluated the associations between hair dye use and risk of overall NHL and common NHL subtypes, stratified by genotype, using unconditional logistic regression. Women who used hair dye before 1980 had a significantly increased risk of NHL, particularly for the follicular lymphoma (FL) subtype, but not for diffuse large B-cell lymphoma. The following genotypes in combination with hair dye use before 1980 were associated with FL risk: BRCA2 rs144848 AC+CC [odds ratio (OR) (95 % confidence interval (CI)) 3.28(1.27-8.50)], WRN rs1346044 TT [OR(95 % CI) 2.70(1.30-5.65)], XRCC3 rs861539 CT+TT [OR(95 % CI) 2.76(1.32-5.77)], XRCC4 rs1805377 GG [OR(95 % CI) 2.07(1.10-3.90)] and rs1056503 TT [OR(95 % CI) 2.17(1.16-4.07)], ERCC1 rs3212961 CC [OR(95 % CI) 1.93(1.00-3.72)], RAD23B rs1805329 CC [OR(95 % CI) 2.28(1.12-4.64)], and MGMT rs12917 CC, rs2308321 AA, and rs2308327 AA genotypes [OR(95 % CI) 1.96(1.06-3.63), 2.02(1.09-3.75), and 2.23(1.16-4.29), respectively]. In addition, a significant interaction with risk of overall NHL was observed between WRN rs1346044 and hair dye use before 1980 (p (interaction) = 0.032). Our results indicated that genetic variation in DNA repair genes modifies susceptibility to NHL in relation to hair dye use, particularly for the FL subtype and in women who began using hair dye before 1980. Further studies are needed to confirm these observations.
Checkpoint Defects Elicit a WRNIP1-Mediated Response to Counteract R-Loop-Associated Genomic Instability
CANCERS
Authors: Marabitti, Veronica; Lillo, Giorgia; Malacaria, Eva; Palermo, Valentina; Pichierri, Pietro; Franchitto, Annapaola
Abstract
Conflicts between replication and transcription are a common source of genomic instability, a characteristic of almost all human cancers. Aberrant R-loops can cause a block to replication fork progression. A growing number of factors are involved in the resolution of these harmful structures and many perhaps are still unknown. Here, we reveal that the Werner interacting protein 1 (WRNIP1)-mediated response is implicated in counteracting aberrant R-loop accumulation. Using human cellular models with compromised Ataxia-Telangiectasia and Rad3-Related (ATR)-dependent checkpoint activation, we show that WRNIP1 is stabilized in chromatin and is needed for maintaining genome integrity by mediating the Ataxia Telangiectasia Mutated (ATM)-dependent phosphorylation of Checkpoint kinase 1 (CHK1). Furthermore, we demonstrated that loss of Werner Syndrome protein (WRN) or ATR signaling leads to formation of R-loop-dependent parental ssDNA upon mild replication stress, which is covered by Radiorestistance protein 51 (RAD51). We prove that Werner helicase-interacting protein 1 (WRNIP1) chromatin retention is also required to stabilize the association of RAD51 with ssDNA in proximity of R-loops. Therefore, in these pathological contexts, ATM inhibition or WRNIP1 abrogation is accompanied by increased levels of genomic instability. Overall, our findings suggest a novel function for WRNIP1 in preventing R-loop-driven genome instability, providing new clues to understand the way replication-transcription conflicts are handled.