Investigator

Tracy O'Mara

Team Head · QIMR Berghofer Medical Research Institute, Cancer Genetic Susceptibility Team

TOTracy O'Mara
Papers(12)
The Multi‐Kinase Inhi…Novel Shared Heritabl…Using Genetics to Inv…Dietary Factors and E…<i><scp>APOBEC3A</scp…10 Years of GWAS disc…Testosterone, sex hor…Genetic analyses of g…Case–case analysis ad…Mendelian randomizati…Co-existence of leiom…Genome‐Wide Associati…
Collaborators(10)
Amanda B. SpurdleHerbert YuImmaculata De VivoXuemin WangPeter A. FaschingCarlotta SacerdoteChristine M Friedenre…Xiao-Ou ShuThilo DörkNicolas Wentzensen
Institutions(9)
Qimr Berghofer Medica…University of Hawaii …Cuny Graduate School …Universittsklinikum E…Universita' degli Stu…University of CalgaryVanderbilt University…Medizinische Hochschu…Division Of Cancer Ep…

Papers

The Multi‐Kinase Inhibitor GZD824 (Olverembatinib) Shows Pre‐Clinical Efficacy in Endometrial Cancer

ABSTRACT Objective Endometrial cancer is one of the few cancers for which mortality is still increasing. A lack of treatment options remains a major challenge, particularly for some subtypes of the disease. GZD824, also known as olverembatinib , is a multi‐kinase inhibitor previously investigated in clinical trials for chronic myeloid leukaemia and Ph+ acute lymphoblastic leukaemia as a BCR‐ABL inhibitor. This study aimed to investigate the pre‐clinical efficacy of GZD824 for the treatment of EC. Methods Here, we undertook pre‐clinical evaluation of GZD824 in seven endometrial cancer cell lines (HEC‐1‐A, HEC‐1‐B, MFE296, RL95‐2, Ishikawa, KLE and ARK‐1), one normal immortalised endometrium derived cell line (E6E7hTERT) and primary mesothelial and fibroblast cells isolated from normal omentum samples. Results GZD824 inhibited the proliferation of all endometrial cancer cell lines, which were significantly more sensitive to GZD824 compared to normal cells ( p  = 0.030). GZD824 significantly inhibited migration in Ishikawa (endometrioid) and ARK1 (serous) endometrial cancer cell lines and significantly inhibited invasion in the ARK1 cells. Whole transcriptome regulation following two doses (0.1 and 1 μM) of GZD824 in Ishikawa and ARK1 cells was investigated via RNA‐seq, and key components of enriched pathways were investigated at the translational level. Key pathways altered included ROR1/Wnt, GCN2‐ATF4, epithelial to mesenchymal transition (EMT) and PI3K‐AKT. Conclusion Together, these studies support further investigation of GZD824 as a potential therapeutic agent in endometrial cancer, potentially in combination with immune checkpoint inhibitors.

APOBEC3A/B deletion polymorphism and endometrial cancer risk

AbstractBackgroundA common 30 kb deletion affecting the APOBEC3A and APOBEC3B genes has been linked to increased APOBEC activity and APOBEC‐related mutational signatures in human cancers. The role of this deletion as a cancer risk factor remains controversial.Materials and MethodsWe genotyped the APOBEC3A/B deletion in a sample of 1,470 Norwegian endometrial cancer cases and compared to 1,918 healthy controls. For assessment across Caucasian populations, we mined genotypes of the SNP rs12628403, which is in strong linkage disequilibrium with the deletion, in a GWAS dataset of 4,274 cases and 18,125 healthy controls, through the ECAC consortium.ResultsWe found the APOBEC3A/B deletion variant to be significantly associated with reduced risk of endometrial cancer among Norwegian women (OR = 0.75; 95% CI = 0.62–0.91; p = 0.003; dominant model). Similar results were found in the subgroup of endometrioid endometrial cancer (OR = 0.64; 95% CI = 0.51–0.79; p = 3.6 × 10−5; dominant model). The observed risk reduction was particularly strong among individuals in the range of 50–60 years of age (OR = 0.51; 95% CI = 0.33–0.78; p = 0.002; dominant model). In the different populations included in the ECAC dataset, the ORs varied from 0.85 to 1.05. Although five out of six populations revealed ORs &lt;1.0, the overall estimate was nonsignificant and, as such, did not formally validate the findings in the Norwegian cohort.ConclusionThe APOBEC3A/B deletion polymorphism is associated with a decreased risk of endometrial cancer in the Norwegian population.

Testosterone, sex hormone-binding globulin, insulin-like growth factor-1 and endometrial cancer risk: observational and Mendelian randomization analyses

Dysregulation of endocrine pathways related to steroid and growth hormones may modify endometrial cancer risk; however, prospective data on testosterone, sex hormone-binding globulin (SHBG) and insulin-like growth factor (IGF)-1 are limited. To elucidate the role of these hormones in endometrial cancer risk we conducted complementary observational and Mendelian randomization (MR) analyses. The observational analyses included 159,702 women (80% postmenopausal) enrolled in the UK Biobank. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. For MR analyses, genetic variants associated with hormone levels were identified and their association with endometrial cancer (12,906 cases/108,979 controls) was examined using two-sample MR. In the observational analysis, higher circulating concentrations of total (HR per unit inverse normal scale = 1.38, 95% CI = 1.22-1.57) and free testosterone (HR per unit log scale = 2.07, 95% CI = 1.66-2.58) were associated with higher endometrial cancer risk. An inverse association was found for SHBG (HR per unit inverse normal scale = 0.76, 95% CI = 0.67-0.86). Results for testosterone and SHBG were supported by the MR analyses. No association was found between genetically predicted IGF-1 concentration and endometrial cancer risk. Our results support probable causal associations between circulating concentrations of testosterone and SHBG with endometrial cancer risk.

Genetic analyses of gynecological disease identify genetic relationships between uterine fibroids and endometrial cancer, and a novel endometrial cancer genetic risk region at the WNT4 1p36.12 locus

Endometriosis, polycystic ovary syndrome (PCOS) and uterine fibroids have been proposed as endometrial cancer risk factors; however, disentangling their relationships with endometrial cancer is complicated due to shared risk factors and comorbidities. Using genome-wide association study (GWAS) data, we explored the relationships between these non-cancerous gynecological diseases and endometrial cancer risk by assessing genetic correlation, causal relationships and shared risk loci. We found significant genetic correlation between endometrial cancer and PCOS, and uterine fibroids. Adjustment for genetically predicted body mass index (a risk factor for PCOS, uterine fibroids and endometrial cancer) substantially attenuated the genetic correlation between endometrial cancer and PCOS but did not affect the correlation with uterine fibroids. Mendelian randomization analyses suggested a causal relationship between only uterine fibroids and endometrial cancer. Gene-based analyses revealed risk regions shared between endometrial cancer and endometriosis, and uterine fibroids. Multi-trait GWAS analysis of endometrial cancer and the genetically correlated gynecological diseases identified a novel genome-wide significant endometrial cancer risk locus at 1p36.12, which replicated in an independent endometrial cancer dataset. Interrogation of functional genomic data at 1p36.12 revealed biologically relevant genes, including WNT4 which is necessary for the development of the female reproductive system. In summary, our study provides genetic evidence for a causal relationship between uterine fibroids and endometrial cancer. It further provides evidence that the comorbidity of endometrial cancer, PCOS and uterine fibroids may partly be due to shared genetic architecture. Notably, this shared architecture has revealed a novel genome-wide risk locus for endometrial cancer.

Mendelian randomization analyses suggest a role for cholesterol in the development of endometrial cancer

AbstractBlood lipids have been associated with the development of a range of cancers, including breast, lung and colorectal cancer. For endometrial cancer, observational studies have reported inconsistent associations between blood lipids and cancer risk. To reduce biases from unmeasured confounding, we performed a bidirectional, two‐sample Mendelian randomization analysis to investigate the relationship between levels of three blood lipids (low‐density lipoprotein [LDL] and high‐density lipoprotein [HDL] cholesterol, and triglycerides) and endometrial cancer risk. Genetic variants associated with each of these blood lipid levels (P &lt; 5 × 10−8) were identified as instrumental variables, and assessed using genome‐wide association study data from the Endometrial Cancer Association Consortium (12 906 cases and 108 979 controls) and the Global Lipids Genetic Consortium (n = 188 578). Mendelian randomization analyses found genetically raised LDL cholesterol levels to be associated with lower risks of endometrial cancer of all histologies combined, and of endometrioid and non‐endometrioid subtypes. Conversely, higher genetically predicted HDL cholesterol levels were associated with increased risk of non‐endometrioid endometrial cancer. After accounting for the potential confounding role of obesity (as measured by genetic variants associated with body mass index), the association between genetically predicted increased LDL cholesterol levels and lower endometrial cancer risk remained significant, especially for non‐endometrioid endometrial cancer. There was no evidence to support a role for triglycerides in endometrial cancer development. Our study supports a role for LDL and HDL cholesterol in the development of non‐endometrioid endometrial cancer. Further studies are required to understand the mechanisms underlying these findings.

Co-existence of leiomyomas, adenomyosis and endometriosis in women with endometrial cancer

AbstractLeiomyomas, adenomyosis, and endometriosis are reported to be risk factors for endometrial carcinoma (EC), and adenomyosis and endometriosis also for ovarian carcinoma (OC). We aimed to describe the prevalence of these conditions in EC patients with or without an OC diagnosis, and to investigate their relationship with EC risk and prognostic factors in these patients. We evaluated the co-existence of these three conditions in 1399 EC patients, and compared the prevalence of epidemiological risk factors and tumor prognostic features in patients with each condition versus not. Prevalence of conditions was also assessed in the subset of patients with prior/concurrent OC. The observed coexistence of leiomyomas, adenomyosis and endometriosis significantly deviated from that expected (P = 1.2 × 10−8). Patients were more likely to: report a younger age at menarche (PTrend = 0.004) if they had leiomyomas; have used oral contraceptives (P = 6.6 × 10−5) or had ≥2 full-term pregnancies (PTrend = 2.0 × 10−9) if they had adenomyosis; be diagnosed with EC at younger age (P = 5.0 × 10−11) if they had endometriosis. Patients with prior/concurrent OC were more likely to be diagnosed at younger age (P = 5.0 × 10−5), have endometriosis (P = 9.9 × 10−7), and present with higher stage EC (PTrend = 6.6 × 10−5). These findings justify further consideration of these gynecologic conditions as independent risk and prognostic factors for EC.

Genome‐Wide Association Analyses of HPV16 and HPV18 Seropositivity Identify Susceptibility Loci for Cervical Cancer

ABSTRACTInfection by high‐risk human papillomavirus is known to exacerbate cervical cancer development. The host immune response is crucial in disease regression. Large‐scale genetic association studies for cervical cancer have identified few susceptibility variants, mainly at the human leukocyte antigen locus on chromosome 6. We hypothesized that the host immune response modifies cervical cancer risk and performed three genome‐wide association analyses for HPV16, HPV18 and HPV16/18 seropositivity in 7814, 7924, and 7924 samples from the UK Biobank, followed by validation genotyping in the German Cervigen case‐control series of cervical cancer and dysplasia. In GWAS analyses, we identified two loci associated with HPV16 seropositivity (6p21.32 and 15q26.2), two loci associated with HPV18 seropositivity (5q31.2 and 14q24.3), and one locus for HPV16 and/or HPV18 seropositivity (at 6p21.32). MAGMA gene‐based analysis identified HLA‐DQA1 and HLA‐DQB1 as genome‐wide significant (GWS) genes. In validation genotyping, the genome‐wide significant lead variant at 6p21.32, rs9272293 associated with overall cervical disease (OR = 0.86, p = 0.004, 95% CI = 0.78–0.95, n = 3710) and HPV16 positive invasive cancer (OR = 0.73, p = 0.005, 95% CI = 0.59–0.91, n = 1431). This variant was found to be a robust eQTL for HLA‐DRB1, HLA‐DQB1‐AS1, C4B, HLA‐DRB5, HLA‐DRB6, HLA‐DQB1, and HLA‐DPB1 in a series of cervical epithelial tissue samples. We additionally genotyped twenty‐four HPV seropositivity variants below the GWS threshold out of which eleven variants were found to be associated with cervical disease in our cohort, suggesting that further seropositivity variants may determine cervical disease outcome. Our study identifies novel genomic risk loci that associate with HPV type‐specific cervical cancer and dysplasia risk and provides evidence for candidate genes at one of the risk loci.

The Effect of Circulating Proteins and Their Role in Mediating Adiposity’s Effect on Endometrial Cancer Risk: Mendelian Randomization and Colocalization Analyses

Abstract Background: Proteomics could enhance our understanding of endometrial carcinogenesis. However, addressing confounding in traditional observational studies remains challenging, especially given the strong impact of adiposity on the plasma proteome and endometrial cancer risk. Methods: Using Mendelian randomization (MR) and colocalization analyses, we examined the causal association between 2,751 unique proteins from the UK Biobank (N proteins = 2,031; N = 52,363) and deCODE (N proteins = 1,667; N = 35,559) with endometrial cancer risk [overall (N cases = 12,270; N controls = 46,126), endometrioid (N cases = 8,758), and nonendometrioid (N cases = 1,230)]. We performed enrichment analyses to explore pathways overrepresented among plasma proteins in endometrioid and nonendometrioid cancer subtypes. We assessed whether circulating proteins mediated the effect of body mass index on endometrial cancer risk using uni- and multivariable MR. Results: Twenty proteins were associated with endometrial cancer risk in MR and colocalization analyses. GSTO1-1 and SKAP1 were positively and MMP10 was negatively associated with overall and endometrioid endometrial cancer; DTYMK and ABO were positively and TSSC4 was negatively associated with overall endometrial cancer; IGF2R was positively associated with endometrioid cancer; and MAPK9 was positively and DNAJB14, IFI16, LCN2, and SCT were negatively associated with nonendometrioid endometrial cancer. Distinct pathways were overrepresented in endometrioid (e.g., platelet-derived growth factor signaling and PTEN gene regulation) and nonendometrioid (e.g., noncanonical NF-κB signaling) cancer subtypes. There was weak evidence of associated proteins mediating the relationship between body mass index and endometrial cancer risk. Conclusions: We identified distinct plasma proteins and pathways associated with endometrioid and nonendometrioid endometrial cancer risk. Impact: Prioritized proteins may support noninvasive methods to differentiate endometrial cancer subtypes.

Hypertension and Risk of Endometrial Cancer: A Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium (E2C2)

Abstract Background: The incidence rates of endometrial cancer are increasing, which may partly be explained by the rising prevalence of obesity, an established risk factor for endometrial cancer. Hypertension, another component of metabolic syndrome, is also increasing in prevalence, and emerging evidence suggests that it may be associated with the development of certain cancers. The role of hypertension independent of other components of metabolic syndrome in the etiology of endometrial cancer remains unclear. In this study, we evaluated hypertension as an independent risk factor for endometrial cancer and whether this association is modified by other established risk factors. Methods: We included 15,631 endometrial cancer cases and 42,239 controls matched on age, race, and study-specific factors from 29 studies in the Epidemiology of Endometrial Cancer Consortium. We used multivariable unconditional logistic regression models to estimate ORs and 95% confidence intervals (CI) to evaluate the association between hypertension and endometrial cancer and whether this association differed by study design, race/ethnicity, body mass index, diabetes status, smoking status, or reproductive factors. Results: Hypertension was associated with an increased risk of endometrial cancer (OR, 1.14; 95% CI, 1.09–1.19). There was significant heterogeneity by study design (Phet &amp;lt; 0.01), with a stronger magnitude of association observed among case–control versus cohort studies. Stronger associations were also noted for pre-/perimenopausal women and never users of postmenopausal hormone therapy. Conclusions: Hypertension is associated with endometrial cancer risk independently from known risk factors. Future research should focus on biologic mechanisms underlying this association. Impact: This study provides evidence that hypertension may be an independent risk factor for endometrial cancer.

93Works
14Papers
96Collaborators
Endometrial NeoplasmsBreast NeoplasmsEndometriosisPolycystic Ovary SyndromeNeoplasmsColorectal NeoplasmsUterine Cervical Neoplasms

Positions

2021–

Team Head

QIMR Berghofer Medical Research Institute · Cancer Genetic Susceptibility Team

2012–

Postdoctoral Fellow

QIMR Berghofer Medical Research Institute · Department of Genetics and Computational Biology

Education

2013

PhD

Queensland University of Technology · Institute of Health and Biomedical Innovation