Genetic alterations of the WWOX gene in breast cancer

Genome-wide linkage search for cancer susceptibility loci in a cohort of non BRCA1/2 families in Sri Lanka

Objective

Although linkage studies have been utilized for the identification of variants associated with cancer in the world, little is known about their role in non BRCA1/2 individuals in the Sri Lankans. Hence we performed linkage analysis to identify susceptibility loci related to the inherited risk of cancer in a cohort of Sri Lankans affected with hereditary breast cancer. The Illumina global screening array having 654,027 single nucleotide polymorphism markers was performed in four families, in which at least three individuals within third degree relatives were affected by breast cancer. Two-point parametric linkage analysis was conducted assuming disease allele frequency of 1%. Penetrance was set at 90% for carriers with a 10% phenocopy rate.

Results

Thirty-one variants exhibited genome-wide suggestive HLODs. The top overall HLOD score was at rs1856277, an intronic variant in MYO16 on chromosome 13. The two most informative families also suggested several candidate linked loci in genes, including ERAP1, RPRM, WWOX, CDH1, EXOC1, HUS1B, STIM1 and TUSC1. This study provides the first step in identifying germline variants that may be involved in risk of cancer in cancer-aggregated non-BRCA1/2 families from the understudied Sri Lankan population. Several candidate linked regions showed suggestive evidence of linkage to cancer risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06081-5.

The WWOX/HIF1A Axis Downregulation Alters Glucose Metabolism and Predispose to Metabolic Disorders

Recent reports indicate that the hypoxia-induced factor (HIF1α) and the Warburg effect play an initiating role in glucotoxicity, which underlies disorders in metabolic diseases. WWOX has been identified as a HIF1α regulator. WWOX downregulation leads to an increased expression of HIF1α target genes encoding glucose transporters and glycolysis’ enzymes. It has been proven in the normoglycemic mice cells and in gestational diabetes patients. The aim of the study was to determine WWOX’s role in glucose metabolism regulation in hyperglycemia and hypoxia to confirm its importance in the development of metabolic disorders. For this purpose, the WWOX gene was silenced in human normal fibroblasts, and then cells were cultured under different sugar and oxygen levels. Thereafter, it was investigated how WWOX silencing alters the genes and proteins expression profile of glucose transporters and glycolysis pathway enzymes, and their activity. In normoxia normoglycemia, higher glycolysis genes expression, their activity, and the lactate concentration were observed in WWOX KO fibroblasts in comparison to control cells. In normoxia hyperglycemia, it was observed a decrease of insulin-dependent glucose uptake and a further increase of lactate. It likely intensifies hyperglycemia condition, which deepen the glucose toxic effect. Then, in hypoxia hyperglycemia, WWOX KO caused weaker glucose uptake and elevated lactate production. In conclusion, the WWOX/HIF1A axis downregulation alters glucose metabolism and probably predispose to metabolic disorders.

Silencing of Wwox Increases Nuclear Import of Dvl proteins in Head and Neck Cancer

Background: Wnt signaling pathway is associated with a variety of human cancers, including HNSCC. Wnt proteins control cellular events such as proliferation, fate specification, polarity, and migration by transducing signals to the nucleus through several cytoplasmic relay proteins. Although activation of the Wnt/β-catenin pathway is a frequent event in various cancers, there is limited knowledge on the contribution of this signaling mechanism in HNSCC. The Wwox tumor suppressor protein participates in the regulation of Wnt signaling by interacting with Dvl proteins.

Methods: In this study, we used qRT-PCR and western blotting to examine the mRNA and protein levels of the Dvls in association with WWOX in HNSCC cell lines and tumor tissues.

Results: We found that silencing of WWOX leads to increased nuclear localization of the Dvl proteins in cell lines. However, we detected an increase only in the nuclear localization of Dvl-1 in tumor tissues.

Conclusions: Our results suggest that aberrant WWOX expression contributes to HNSCC through the Wnt signaling pathway. Decreased expression of WWOX may function in HNSCC progression by allowing the nuclear localization of Dvl proteins.

Downregulation of WW domain-containing oxidoreductase leads to tamoxifen-resistance by the inactivation of Hippo signaling

Acquired tamoxifen-resistance is an important cause of death in patients with hormone-dependent breast tumors. Therefore, understanding the molecular mechanisms underlying the development of tamoxifen-resistance is critical for successful endocrine therapy. This study aimed to define the role of WW domain-containing oxidoreductase (WWOX) in acquired tamoxifen-resistance. Our results show that low WWOX expression was significantly related to tamoxifen-resistance. Moreover, WWOX-knockdown increased resistance to tamoxifen, while WWOX overexpression decreased the resistance. Furthermore, WWOX silencing decreased Yes-associated protein (YAP) phosphorylation and increased YAP nuclear translocation. Finally, YAP silencing decreased tamoxifen-resistance in WWOX-knockdown cells. Our findings demonstrate that WWOX downregulation can lead to the development of tamoxifen-resistance by inactivating Hippo signaling. Thus, WWOX might be a valuable target and prognostic marker for tamoxifen-resistance.

Impact statement

Understanding the molecular pathways leading to the development of tamoxifen-resistance is an important research focus as acquired tamoxifen-resistance is the main cause of death in patients with benign primary prognosis. Although WW domain-containing oxidoreductase (WWOX) has been related to breast tumorigenesis, its role in acquired tamoxifen-resistance has not yet been demonstrated. Our findings show that WWOX might be a valuable therapeutic target and prognostic marker for tamoxifen-resistance.

WWOX Tumor Suppressor Gene in Breast Cancer, a Historical Perspective and Future Directions

The WWOX tumor suppressor gene is located at 16q23. 1–23.2, which covers the region of FRA16D—a common fragile sites. Deletions within the WWOX coding sequence are observed in up to 80% of breast cancer cases, which makes it one of the most common genetic alterations in this tumor type. The WWOX gene is known to play a role in breast cancer: increased expression of WWOX inhibits cell proliferation in suspension, reduces tumor growth rates in xenographic transplants, but also enhances cell migration through the basal membrane and contributes to morphological changes in 3D matrix-based cell cultures. The WWOX protein may act in several ways, as it has three functional domains—two WW domains, responsible for protein-protein interactions and an SDR domain (short dehydrogenase/reductase domain) which catalyzes conversions of low molecular weight ligands, most likely steroids. In epithelial cells, WWOX modulates gene transcription through interaction with p73, AP-2γ, and ERBB4 proteins. In steroid hormone-regulated tissues like mammary gland epithelium, the WWOX SDR domain acts as a steroid dehydrogenase. The relationship between WWOX and hormone receptors was shown in an animal model, where WWOX(C3H)+/–mice exhibited loss of both ER and PR receptors. Moreover, in breast cancer specimens, a positive correlation was observed between WWOX expression and ER status. On the other hand, decreased WWOX expression was associated with worse prognosis, namely higher relapse and mortality rates in BC patients. Recently, it was shown that genomic instability might be driven by the loss of WWOX expression. It was reported that WWOX plays role in DNA damage response (DDR) and DNA repair by regulating ATM activation through physical interaction. A genome caretaker function has also been proposed for WWOX, as it was found that WWOX sufficiency decreases homology directed repair (HDR) and supports non-homologous end-joining (NHEJ) repair as the dominant DSB repair pathway by Brca1-Wwox interaction. In breast cancer cells, WWOX was also found to modulate the expression of glycolysis pathway genes, through hypoxia-inducible transcription factor 1α (HIF1α) regulation. The paper presents the current state of knowledge regarding the WWOX tumor suppressor gene in breast cancer, as well as future research perspectives.

Combinations of single nucleotide polymorphisms WWOX-rs13338697, GALNT14-rs9679162 and rs6025211 effectively stratify outcomes of chemotherapy in advanced hepatocellular carcinoma

AIM

A genome-wide association study (GWAS) had identified a single nucleotide polymorphism (SNP), GALNT14-rs9679162, capable of predicting chemotherapy responses in advanced hepatocellular carcinoma (HCC). Here, we revisited the GWAS database to search for necessary SNPs that could improve our outcome prediction.

METHODS

A cohort of 116 HCC patients receiving split-dose chemotherapy composed of 5-fluorouracil, mitoxantrone and cisplatin was enrolled. The GALNT14-rs9679162 together with four other leading candidate SNPs (rs6025211, rs715171, LOC105369482-rs1955024 and WWOX-rs13338697) was genotyped and correlated with time-to-tumor progression (TTP) and overall survival (OS).

RESULTS

GALNT14-rs9679162-TT genotype remained an effective predictor for favorable TTP and OS (P = 0.012 and 0.002). Additionally, it was found that WWOX-rs13338697-CT genotype was associated with unfavorable TTP (P = 0.031), independent of GALNT14-rs9679162 genotype (adjusted P = 0.045), and rs6025211-CT genotype was associated with unfavorable OS (P = 0.014), independent of GALNT14-rs9679162 genotype (adjusted P = 0.025). Combinations of these SNPs stratified patients into three groups with differential treatment outcomes. Patients with GALNT14-rs9679162-TT/WWOX-rs13338697-non-CT genotypes achieved the most favorable treatment outcomes (n = 19; median TTP, median OS and response rate were 3.9 months, 6.8 months and 4/19 [21.1%], respectively); whereas patients with GALNT14-rs9679162-non-TT/rs6025211-CT genotypes associated with the most unfavorable treatment outcomes (n = 40; median TTP, median OS and response rate were 1.9 months, 3.5 months and 1/40 [2.5%], respectively). The remaining patients constituted a third subgroup with intermediate clinical outcomes.

CONCLUSIONS

Three genetic variants, GALNT14-rs9679162, WWOX-rs13338697 and rs6025211, stratified advanced HCC patients into three groups with differential treatment outcomes.

Exploring the mechanism of WWOX growth inhibitory effects on oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common types of head and neck neoplasms in the world. Patients diagnosed with OSCC exhibit a poor prognosis. WW domain-containing oxidoreductase (WWOX), as a candidate tumor-suppressor gene, is involved in the genesis and progression of tumors. The deletion of the WWOX gene has been identified in OSCC and oral leukoplakia, but the function and mechanism of WWOX in OSCC remain unknown. Therefore, the present study investigated the role of WWOX in oral squamous carcinoma cells. The results revealed that an elevation of WWOX expression had an inhibitory effect on the growth of three types of oral squamous carcinoma cells, with the most evident effect occurring in Tca8113 cells. Also, in the Tca8113 cells, WWOX overexpression significantly inhibited colony formation, and induced apoptosis and cell cycle arrest. Microarray analysis, reverse transcription-quantitative polymerase chain reaction and western blotting methods detected that WWOX overexpression contributed to the differential expression of the genes involved in mediating the extracellular-signal regulated protein kinase/mitogen-activated protein kinase (ERK/MAPK) signaling pathway. These results suggest that the tumor-suppressor function of the WWOX gene may be associated with the modulation of the ERK/MAPK signaling pathway, thus providing a novel target for OSCC therapy.

HYAL-2-WWOX-SMAD4 Signaling in Cell Death and Anticancer Response

Hyaluronidase HYAL-2 is a membrane-anchored protein and also localizes, in part, in the lysosome. Recent study from animal models revealed that both HYAL-1 and HYAL-2 are essential for the metabolism of hyaluronan (HA). Hyal-2 deficiency is associated with chronic thrombotic microangiopathy with hemolytic anemia in mice due to over accumulation of high molecular size HA. HYAL-2 is essential for platelet generation. Membrane HYAL-2 degrades HA bound by co-receptor CD44. Also, in a non-canonical signal pathway, HYAL-2 serves as a receptor for transforming growth factor beta (TGF-β) to signal with downstream tumor suppressors WWOX and SMAD4 to control gene transcription. When SMAD4 responsive element is overly driven by the HYAL-2–WWOX–SMAD4 signaling complex, cell death occurs. When rats are subjected to traumatic brain injury, over accumulation of a HYAL-2–WWOX complex occurs in the nucleus to cause neuronal death. HA induces the signaling of HYAL-2–WWOX–SMAD4 and relocation of the signaling complex to the nucleus. If the signaling complex is overexpressed, bubbling cell death occurs in WWOX-expressing cells. In addition, a small synthetic peptide Zfra (zinc finger-like protein that regulates apoptosis) binds membrane HYAL-2 of non-T/non-B spleen HYAL-2⁺ CD3⁻ CD19⁻ Z lymphocytes and activates the cells to generate memory anticancer response against many types of cancer cells in vivo. Whether the HYAL-2–WWOX–SMAD4 signaling complex is involved is discussed. In this review and opinion article, we have updated the current knowledge of HA, HYAL-2 and WWOX, HYAL-2–WWOX–SMAD4 signaling, bubbling cell death, and Z cell activation for memory anticancer response.

Reduced expression of the WW domain-containing oxidoreductase in human hematopoietic malignancies

The role of the WW domain-containing oxidoreductase (WWOX) gene in multiple types of solid human cancers has been documented extensively thus far. Recently, we investigated the in vitro effects of WWOX overexpression and observed marked growth arrest in human leukemia cells; however, the clinical characterization of WWOX in leukemia remains poorly investigated. The present study evaluated the WWOX expression profiles of 182 patients with leukemia of different types and 5 leukemic cell lines, using reverse transcription-polymerase chain reaction and immunofluorescence analysis. The results found that WWOX mRNA and WWOX protein expression was significantly reduced or absent in the leukemia cases and cell lines compared with paired controls. The WWOX-positive rate was also lower in the leukemia cases compared with the rate of the normal controls. Notably, the WWOX level was reduced in newly diagnosed and relapsed cases, or in chronic myelogenous leukemia in the blastic phase, yet elevated in remission samples. Moreover, WWOX-negative cases exhibited WWOX expression restoration following induced remission. These findings suggest that WWOX may contribute to the occurrence and development of leukemia, and that it has potential to be a good biomarker or predictor for leukemia therapy.

WWOX: a fragile tumor suppressor

WWOX, the WW domain-containing oxidoreductase gene at chromosome region 16q23.3-q24.1, spanning chromosomal fragile site FRA16D, encodes the 46 kDa Wwox protein, a tumor suppressor that is lost or reduced in expression in a wide variety of cancers, including breast, prostate, ovarian, and lung. The function of Wwox as a tumor suppressor implies that it serves a function in the prevention of carcinogenesis. Indeed, in vitro studies show that Wwox protein interacts with many binding partners to regulate cellular apoptosis, proliferation, and/or maturation. It has been reported that newborn Wwox knockout mice exhibit nascent osteosarcomas while Wwox(+/-) mice exhibit increased incidence of spontaneous and induced tumors. Furthermore, absence or reduction of Wwox expression in mouse xenograft models results in increased tumorigenesis, which can be rescued by Wwox re-expression, though there is not universal agreement among investigators regarding the role of Wwox loss in these experimental models. Despite this proposed tumor suppressor function, the overlap of the human WWOX locus with FRA16D sensitizes the gene to protein-inactivating deletions caused by replication stress. The high frequency of deletions within the WWOX locus in cancers of various types, without the hallmark protein inactivation-associated mutations of "classical" tumor suppressors, has led to the proposal that WWOX deletions in cancers are passenger events that occur in early cancer progenitor cells due to fragility of the genetic locus, rather than driver events which provide the cancer cell a selective advantage. Recently, a proposed epigenetic cause of chromosomal fragility has suggested a novel mechanism for early fragile site instability and has implications regarding the involvement of tumor suppressor genes at chromosomal fragile sites in cancer. In this review, we provide an overview of the evidence for WWOX as a tumor suppressor gene and put this into the context of fragility associated with the FRA16D locus.

Roles of the WWOX in pathogenesis and endocrine therapy of breast cancer

Breast cancer is one of the most common malignancies, often with complicated etiology and poor clinical outcome. In recent years, a critical role has emerged for the WW domain-containing oxidoreductase (WWOX) in breast cancer. WWOX is a tumor suppressor; it is deleted or attenuated in 29-63.2% of breast cancer tissues and is associated with a poor prognosis of breast cancer patients. WWOX heterozygous knockout mice show a higher incidence of mammary tumors and impaired branching morphogenesis. At the molecular level, WWOX interacts with AP2γ, ErbB4, SMAD3, and WBP2 suppressing their transcription activities in breast cancer cell lines. This review provides comprehensive insights into the current knowledge of WWOX activities in the pathogenesis and endocrine therapy of breast cancer.

Epigenetic and genetic alterations affect the WWOX gene in head and neck squamous cell carcinoma

Different types of genetic and epigenetic changes are associated with HNSCC. The molecular mechanisms of HNSCC carcinogenesis are still undergoing intensive investigation. WWOX gene expression is altered in many cancers and in a recent work reduced WWOX expression has been associated with miR-134 expression in HNSCC. In this study we investigated the WWOX messenger RNA expression levels in association with the promoter methylation of the WWOX gene and miR-134 expression levels in 80 HNSCC tumor and non-cancerous tissue samples. Our results show that WWOX expression is down-regulated especially in advanced-stage tumor samples or in tumors with SCC. This down-regulation was associated with methylation of the WWOX promoter region but not with miR-134 expression. There was an inverse correlation between the expression level and promoter methylation. We also analyzed whole exons and exon/intron boundries of the WWOX gene by direct sequencing. In our study group we observed 10 different alterations in the coding sequences and 18 different alterations in the non-coding sequences of the WWOX gene in HNSCC tumor samples. These results indicate that the WWOX gene can be functionally inactivated by promoter methylation, epigenetically or by mutations affecting the sequences coding for the enzymatic domain of the gene, functionally. We conclude that inactivation of WWOX gene contributes to the progression of HNSCC.

WWOX, large common fragile site genes, and cancer

WWOX is a gene that spans an extremely large chromosomal region. It is derived from within chromosomal band 16q23.2 which is a region with frequent deletions and other alterations in a variety of different cancers. This chromosomal band also contains the FRA16D common fragile site (CFS). CFSs are chromosomal regions found in all individuals which are highly unstable. WWOX has also been demonstrated to function as a tumor suppressor that is involved in the development of many cancers. Two other highly unstable CFSs, FRA3B (3p14.2) and FRA6E (6q26), also span extremely large genes, FHIT and PARK2, respectively, and these two genes are also found to be important tumor suppressors. There are a number of interesting similarities between these three large CFS genes. In spite of the fact that they are derived from some of the most unstable chromosomal regions in the genome, they are found to be highly evolutionarily conserved and the chromosomal region spanning the mouse homologs of both WWOX and FHIT are also CFSs in mice. Many of the other CFSs also span extremely large genes and many of these are very attractive tumor suppressor candidates. WWOX is therefore a member of a very interesting family of very large CFS genes.

The WWOX gene inhibits the growth of U266 multiple myeloma cells by triggering the intrinsic apoptotic pathway

The role of the WW domain-containing oxidoreductase (WWOX) gene in multiple types of solid human cancers has been documented extensively. However, the functional role of WWOX in human multiple myeloma has not yet been fully elucidated. The present study aimed to investigate the effects of exogenous WWOX expression on the biological properties of U266 multiple myeloma cells, as well as the possible molecular mechanisms involved. In vitro experiments revealed that exogenous WWOX cDNA transfection resulted in marked growth arrest and the induction of apoptosis in the U266 multiple myeloma cells, accompanied by the activation of the intrinsic apoptotic pathway. Our data provide evidence that WWOX also plays a role as a tumor suppressor gene in multiple myeloma, possibly by suppressing cell proliferation and promoting apoptosis by triggering the intrinsic apoptotic pathway.

Expanding the genetic basis of copy number variation in familial breast cancer

Introduction

Familial breast cancer (fBC) is generally associated with an early age of diagnosis and a higher frequency of disease among family members. Over the past two decades a number of genes have been identified that are unequivocally associated with breast cancer (BC) risk but there remain a significant proportion of families that cannot be accounted for by these genes. Copy number variants (CNVs) are a form of genetic variation yet to be fully explored for their contribution to fBC. CNVs exert their effects by either being associated with whole or partial gene deletions or duplications and by interrupting epigenetic patterning thereby contributing to disease development. CNV analysis can also be used to identify new genes and loci which may be associated with disease risk.

Methods

The Affymetrix Cytogenetic Whole Genome 2.7 M (Cyto2.7 M) arrays were used to detect regions of genomic re-arrangement in a cohort of 129 fBC BRCA1/BRCA2 mutation negative patients with a young age of diagnosis (<50 years) compared to 40 unaffected healthy controls (>55 years of age).

Results

CNV analysis revealed the presence of 275 unique rearrangements that were not present in the control population suggestive of their involvement in BC risk. Several CNVs were found that have been previously reported as BC susceptibility genes. This included CNVs in RPA3, NBN (NBS1), MRE11A and CYP19A1 in five unrelated fBC patients suggesting that these genes are involved in BC initiation and/or progression. Of special interest was the identification of WWOX and FHIT rearrangements in three unrelated fBC patients.

Conclusions

This study has identified a number of CNVs that potentially contribute to BC initiation and/or progression. The identification of CNVs that are associated with known tumour suppressor genes is of special interest that warrants further larger studies to understand their precise role in fBC.

WW domain-containing oxidoreductase's role in myriad cancers: clinical significance and future implications

The WW domain-containing oxidoreductase (WWOX) gene, encodes a tumor suppressor located on 16q23.1, spanning FRA16D, one of the most active common fragile sites in the human genome, that is altered in numerous types of cancer. WWOX's alteration in these myriad cancers is due to disparate mechanisms including loss of heterozygosity, homozygous deletion and epigenetic changes. In vitro, WWOX has been found to be reduced or absent in numerous cancer cell lines and WWOX restoration has been found to inhibit tumor cell growth and invasion. Wwox knockout mice developed femoral focal lesions resembling osteosarcomas within one month of their life and aging Wwox heterozygous mice have an increased incidence of spontaneous lung and mammary tumors as well as B-cell lymphomas. We herein review WWOX's role that has been unearthed thus far in different types of malignancies, its clinical significance and future implications.

Single-nucleotide polymorphism-array improves detection rate of genomic alterations in core-binding factor leukemia

Acute myeloid leukemia (AML) is a group of clonal diseases, resulting from two classes of mutation. Investigation for additional abnormalities associated with a well-recognized subtype, core-binding factor AML (CBF-AML) can provide further understanding and discrimination to this special group of leukemia. In order to better define genetic alterations in CBF-AML and identify possible cooperating lesions, a single-nucleotide polymorphism-array (SNP-array) analysis was performed, combined to KIT mutation screening, in a set of cases. Validation of SNP-array results was done by array comparative genomic hybridization and FISH. Fifteen cases were analyzed. Three cases had microscopic lesions better delineated by arrays. One case had +22 not identified by arrays. Submicroscopic abnormalities were mostly non-recurrent between samples. Of relevance, four regions were more frequently affected: 4q28, 9p11, 16q22.1, and 16q23. One case had an uncovered unbalanced inv(16) due to submicroscopic deletion of 5´MYH11 and 3´CBFB. Telomeric and large copy number neutral loss of heterozygosity (CNN-LOH) regions (>25 Mb), likely representing uniparental disomy, were detected in four out of fifteen cases. Only three cases had mutation on KIT gene, enhancing the role of abnormalities by SNP-array as presumptive cooperating alterations. Molecular karyotyping can add valuable information to metaphase karyotype analysis, emerging as an important tool to uncover and characterize microscopic, submicroscopic genomic alterations, and CNN-LOH events in the search for cooperating lesions.

A multistage genetic association study identifies breast cancer risk loci at 10q25 and 16q24

BACKGROUND

Heritable risk for breast cancer includes an increasing number of common, low effect risk variants. We conducted a multistage genetic association study in a series of independent epidemiologic breast cancer study populations to identify novel breast cancer risk variants.

METHODS

We tested 1,162 SNPs of greatest nominal significance from stage I of the Cancer Genetic Markers of Susceptibility breast cancer study (CGEMS; 1,145 cases, 1,142 controls) for evidence of replicated association with breast cancer in the Nashville Breast Cohort (NBC; 599 cases, 1,161 controls), the Collaborative Breast Cancer Study (CBCS; 1,552 cases, 1,185 controls), and BioVU Breast Cancer Study (BioVU; 1,172 cases, 1,172 controls).

RESULTS

Among these SNPs, a series of validated breast cancer risk variants yielded expected associations in the study populations. In addition, we observed two previously unreported loci that were significantly associated with breast cancer risk in the CGEMS, NBC, and CBCS study populations and had a consistent, although not statistically significant, risk effect in the BioVU study population. These were rs1626678 at 10q25.3 near ENO4 and KIAA1598 (meta-analysis age-adjusted OR = 1.13 [1.07-1.20], P = 5.6 × 10(-5)), and rs8046508 at 16q23.1 in the eighth intron of WWOX (meta-analysis age-adjusted OR = 1.20 [1.10-1.31], P = 3.5 × 10(-5)).

CONCLUSIONS

Our data supports the association of two novel loci, at 10q25.3 and 16q23.1, with risk of breast cancer.

IMPACT

The expanding compendium of known breast cancer genetic risk variants holds increasing power for clinical risk prediction models of breast cancer, improving upon the Gail model.