AbstractIntroductionAfrican‐American (AA) individuals have a higher risk for late‐onset Alzheimer's disease (LOAD) than Americans of primarily European ancestry (EA). Recently, the largest genome‐wide association study in AAs to date confirmed that six of the Alzheimer's disease (AD)‐related genetic variants originally discovered in EA cohorts are also risk variants in AA; however, the risk attributable to many of the loci (e.g., APOE, ABCA7) differed substantially from previous studies in EA. There likely are risk variants of higher frequency in AAs that have not been discovered.MethodsWe performed a comprehensive analysis of genetically determined local and global ancestry in AAs with regard to LOAD status.ResultsCompared to controls, LOAD cases showed higher levels of African ancestry, both globally and at several LOAD relevant loci, which explained risk for AD beyond global differences.DiscussionExploratory post hoc analyses highlight regions with greatest differences in ancestry as potential candidate regions for future genetic analyses.
Abstract 2741: Sensitization of temozolomide-mediated glioblastoma cell death by targeting MDM2: Assessment of PD biomarkers, brain penetration, and efficacy in humanized orthotopic xenograft models
Abstract Treatment of glioblastoma multiforme (GBM) continues to be a challenge due to its infiltrative nature, tumor heterogeneity, and lack of therapeutic agents that penetrate the blood-brain barrier (BBB). While the primary tumor is permeable to some degree, the ability of GBM cells to invade areas of parenchyma with an intact BBB indicates development of BBB-penetrable compounds is a necessity. The multifunctional protein MDM2 holds promise as a therapeutic target in a variety of cancers and plays a critical role in controlling cell survival, invasion, and DNA repair. MDM2 antagonists such as nutlin3a and RG7112 are being used to interrogate the impact of modulating MDM2 function in combination with front-line therapy. Our objective was to investigate whether MDM2 antagonists, alone or in combination with temozolomide (TMZ), can augment cell death in orthotopic GBM xenograft models. In vitro data indicate that TMZ and nutlin3a are synergistic in decreasing cell viability in wild type (wt) p53 U87-MG, primary human wt p53 GBM10 and mutant (mt) p53 GBM43 cells. Pharmacodynamic studies demonstrated that the mechanism of action for promoting cell death following exposure to TMZ/nutlin3a was multifactorial. Comet assays indicated that repair of TMZ-mediated DNA damage was significantly delayed in wt and mt p53 GBM cells treated with TMZ/nutlin3a compared to TMZ alone and the base excision repair protein Ape1 was downregulated in cells treated with TMZ/nutlin3a. Pharmacokinetic studies guided development of rational dosing regimens in which 2-3 five-day cycles of TMZ followed by nutlin3a 4 hours later were investigated. In ectopic U87-MG xenografts, nutlin3a sensitized xenografts to TMZ-mediated cell death. Orthotopic studies employing U87-MG, GBM10, and GBM43 tumors are being utilized to determine if nutlin3a levels detectable in the brain via HPLC-MS/MS(API 4000) are sufficient to modulate MDM2 function in the context of TMZ and increase survival. In the TMZ-resistant GBM10 (wtp53, MGMTpos, and PTENnull) orthotopic model, there was a modest increase in median survival from 63 days with TMZ to 73 days with TMZ/nutlin3a. Higher and more sustained brain levels of MDM2 antagonists will likely be necessary to improve survival. The MDM2 antagonist RG7112 has an improved PK profile and structural analysis of RG7112 and nutlin3a via QikProp 3.0 (www.schrodinger.com) indicates that RG7112 also has an improved predicted brain/blood partition coefficient (plog BB) compared to nutlin3a (RG7112 = -0.17; nutlin3a = -0.415). Studies are in progress to assess the brain penetration of RG7112 and its effect on GBM growth in vivo. Taken together, our data suggest that modulation of MDM2 function in the context of cytotoxic therapy has the potential to alter mechanisms involved in DNA repair that can promote cell death and improve survival. Citation Format: Haiyan Wang, Shanbao Cai, Barbara J. Bailey, Lawrence M. Gelbert, M. Reza Saadatzadeh, Aaron A. Cohen-Gadol, Jann N. Sarkaria, Paul Territo, Taxiarchis M. Georgiadis, T. Zachary Gunter, Samy Meroueh, Eric C. Long, David R. Jones, Lindsey D. Mayo, Shannon Harlan, Karen E. Pollok. Sensitization of temozolomide-mediated glioblastoma cell death by targeting MDM2: Assessment of PD biomarkers, brain penetration, and efficacy in humanized orthotopic xenograft models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2741. doi:10.1158/1538-7445.AM2014-2741
Abstract S1-06: Stromal tumor-infiltrating lymphocytes(S-TILs): In the alliance N9831 trial S-TILs are associated with chemotherapy benefit but not associated with trastuzumab benefit
Abstract Background: Tumor-infiltrating lymphocytes (TILs) at diagnosis are reported to be prognostic in triple-negative breast cancer (BC). Analysis of a small subset of 209 HER2+ patients (pts) with 49 events concluded that higher levels of S-TILs are associated with increased trastuzumab benefit (Loi, 2014). Here we report the largest study to date evaluating S-TILs and their prognostic and predictive association with clinical outcome in N9831 pts treated with either chemotherapy or chemotherapy plus trastuzumab. Methods: Samples assessed were from primary tumors of pts on N9831 arm A (standard AC→T chemotherapy) and arm C (concurrent chemotherapy with trastuzumab) (Perez, 2011). S-TILs were evaluated on H&E whole tumor slides by a single pathologist with ∼10% of cases read by two pathologists in tandem. The percent of stromal lymphocytic infiltrates (S-TILs) was quantitated in deciles; ≥60% S-TILs was used for the categorical cutoff (Denkert, 2010). The association between S-TILs, treatment (tx) and recurrence-free survival (RFS) was studied and the interaction between S-TILs, trastuzumab benefit and RFS was calculated. Results: 489 pts from arm A (chemo) and 456 pts from arm C (chemo with trastuzumab) were assessed and were similar to pts in the overall trial; all had RFS information and a median follow-up of 4.4yr. Tumors from 54% of pts in arms A and C were HR+; 14% were node-negative. Tumors with high S-TILs were more likely to be hormone receptor-negative (p< 0.0001). In multivariable analyses including nodal status, hormone receptor status, tx arm, tumor size, tumor grade, and age, ≥60% S-TILs was significantly associated with RFS (HR 0.20; 95%CI 0.064–0.65, p=0.007) in arm A but not in arm C (HR 1.1; 95%CI 0.42–2.8, p=0.87); the interaction term of arm and ≥60% S-TILs was significant (p=0.042). Semi-continuous deciles were associated with RFS in arm A (p<0.0002) but not in C (p=0.37). Hormone receptor status was an independent prognostic factor in arm A (HR 0.61; 95%CI 0.41-0.93, p=0.02) but not in C (HR 0.79; 95%CI 0.44-1.41, p=0.42). In arm A the 10yr Kaplan-Meier estimates for RFS were 90.9% and 64.5% for high S-TILs and low S-TILs pts, respectively (HR 0.23; 95%CI 0.073–0.73, p=0.013). In arm C the 10yr Kaplan-Meier estimates for RFS were 80.0% and 80.1% for high S-TILs and low S-TILs pts, respectively (HR 1.26; 95%CI 0.5–3.2, p=0.63). Arm A (N=489)Arm C (N=456)VariableHR (95% CI)p-valueHR (95% CI)p-valueNodal statusLymph node(-)1.00 (ref)<0.00011.00 (ref)0.0131-3+0.58 (0.25, 1.35) 2.99 (0.40, 22.70) 4-91.46 (0.64, 3.35) 3.29 (0.42, 25.80) 10+2.42 (1.04, 5.64) 8.22 (1.06, 63.60) HR statusnegative1.00 (ref)0.01981.00 (ref)0.42positive0.61 (0.41, 0.93) 0.79 (0.44, 1.41) S-TILs status<60%1.00 (ref)0.0071.00 (ref)0.87≥60%0.2 (0.06, 0.65) 1.08 (0.42, 2.79) Tumor gradeGrade 1 or 21.00 (ref)0.501.00 (ref)0.51Grade 31.18 (0.73, 1.91) 1.24 (0.65, 2.39) Tumor size1.08 (0.98, 1.19)0.121.00 (0.93, 1.07)0.92Age0.99 (0.97, 1.00)0.131 (0.98, 1.03)0.87 Conclusions: In exploratory analyses from this subset HER2+ population from N9831, S-TILs were associated with RFS in patients treated with chemotherapy alone, and were not shown to be associated with RFS in patients treated with chemotherapy plus trastuzumab. Citation Format: Edith A Perez, Karla V Ballman, S Keith Anderson, E Aubrey Thompson, Sunil S Badve, Helen Bailey, Frederick L Baehner. Stromal tumor-infiltrating lymphocytes(S-TILs): In the alliance N9831 trial S-TILs are associated with chemotherapy benefit but not associated with trastuzumab benefit [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr S1-06.
Contributions of Increasing Obesity and Diabetes to Slowing Decline in Subclinical Coronary Artery Disease
Background Our previous study of nonelderly adult decedents with nonnatural (accident, suicide, or homicide) cause of death (96% autopsy rate) between 1981 and 2004 revealed that the decline in subclinical coronary artery disease ( CAD ) ended in the mid‐1990s. The present study investigated the contributions of trends in obesity and diabetes mellitus to patterns of subclinical CAD and explored whether the end of the decline in CAD persisted. Methods and Results We reviewed provider‐linked medical records for all residents of Olmsted County, Minnesota , who died from nonnatural causes within the age range of 16 to 64 years between 1981 and 2009 and who had CAD graded at autopsy. We estimated trends in CAD risk factors including age, sex, systolic blood pressure, diabetes (qualifying fasting glucose or medication), body mass index, smoking, and diagnosed hyperlipidemia. Using multiple regression, we tested for significant associations between trends in CAD risk factors and CAD grade and assessed the contribution of trends in diabetes and obesity to CAD trends. The 545 autopsied decedents with recorded CAD grade exhibited significant declines between 1981 and 2009 in systolic blood pressure and smoking and significant increases in blood pressure medication, diabetes, and body mass index ≥30 kg/m 2 . An overall decline in CAD grade between 1981 and 2009 was nonlinear and ended in 1994. Trends in obesity and diabetes contributed to the end of CAD decline. Conclusions Despite continued reductions in smoking and blood pressure values, the previously observed end to the decline in subclinical CAD among nonelderly adult decedents was apparent through 2009, corresponding with increasing obesity and diabetes in that population.
Circulating C-Type Natriuretic Peptide and Its Relationship to Cardiovascular Disease in the General Population
C-type natriuretic peptide (CNP) is an endothelium-derived peptide that is released as a protective mechanism in response cardiovascular injury or disease. However, no studies have investigated circulating CNP, identifying clinical factors that may influence CNP and its relationship to cardiovascular disease in the general population. We studied 1841 randomly selected subjects from Olmsted County, MN (mean age, 63±11 years; 48% men). Plasma CNP was measured by a well-established radioimmunoassay and echocardiography, clinical characterization, and detailed medical record review were performed. We report that CNP circulates at various concentrations (median, 13 pg/mL), was unaffected by sex, was weakly associated by age, and that highest quartile of CNP identified a high-risk phenotype. Subjects with CNP in the highest quartile were associated with increased risk of myocardial infarction (multivariable-adjusted hazard ratio, 1.51; 95% confidence interval, 1.09–2.09; P =0.01) but not heart failure, cerebrovascular accidents, or death during a follow-up of 12 years. Addition of the highest quartile of CNP to clinical variables led to a modest increase in the integrated discrimination improvement for risk of myocardial infarction. In a large community-based cohort, elevated circulating CNP identified a high-risk phenotype that included cardiovascular comorbidities and left ventricular dysfunction, and provided evidence that highest concentrations of CNP potentially has prognostic value in predicting future risk of myocardial infarction. Together, these data from the general population highlight the potential value of CNP and support the need for additional studies to evaluate whether mechanisms regulating CNP could improve outcomes.
BRCA1 Circos: a visualisation resource for functional analysis of missense variants
Background Inactivating germline mutations in the tumour suppressor gene BRCA1 are associated with a significantly increased risk of developing breast and ovarian cancer. A large number (>1500) of unique BRCA1 variants have been identified in the population and can be classified as pathogenic, non-pathogenic or as variants of unknown significance (VUS). Many VUS are rare missense variants leading to single amino acid changes. Their impact on protein function cannot be directly inferred from sequence information, precluding assessment of their pathogenicity. Thus, functional assays are critical to assess the impact of these VUS on protein activity. BRCA1 is a multifunctional protein and different assays have been used to assess the impact of variants on different biochemical activities and biological processes. Methods and results To facilitate VUS analysis, we have developed a visualisation resource that compiles and displays functional data on all documented BRCA1 missense variants. BRCA1 Circos is a web-based visualisation tool based on the freely available Circos software package. The BRCA1 Circos web tool (http://research.nhgri.nih.gov/bic/circos/) aggregates data from all published BRCA1 missense variants for functional studies, harmonises their results and presents various functionalities to search and interpret individual-level functional information for each BRCA1 missense variant. Conclusions This research visualisation tool will serve as a quick one-stop publically available reference for all the BRCA1 missense variants that have been functionally assessed. It will facilitate meta-analysis of functional data and improve assessment of pathogenicity of VUS.
The High-Dose Aldesleukin “Select” Trial: A Trial to Prospectively Validate Predictive Models of Response to Treatment in Patients with Metastatic Renal Cell Carcinoma
We sought to investigate the role of aldosterone as a mediator of disease and its relationship with the counter-regulatory natriuretic peptide (NP) system. We measured plasma aldosterone (n=1674; aged≥45 years old) in a random sample of the general population from Olmsted County, MN. In a multivariate logistic regression model, aldosterone analyzed as a continuous variable was associated with hypertension (odds ratio [OR]=1.75; 95% confidence interval [CI]=1.57–1.96; P <0.0001), obesity (OR=1.34; 95% CI=1.21–1.48; P <0.0001), chronic kidney disease (OR=1.39; 95% CI=1.22–1.60; P <0.0001), central obesity (OR=1.47; 95% CI=1.32–1.63; P <0.0001), metabolic syndrome (OR=1.41; 95% CI=1.26–1.58; P <0.0001), high triglycerides (OR=1.23; 95% CI=1.11–1.36; P <0.0001), concentric left ventricular hypertrophy (OR=1.22; 95% CI=1.09–1.38; P =0.0007), and atrial fibrillation (OR=1.24; 95% CI=1.01–1.53; P =0.04), after adjusting for age and sex. The associations with hypertension, central obesity, metabolic syndrome, triglycerides, and concentric left ventricular hypertrophy remained significant after further adjustment for body mass index, NPs, and renal function. Furthermore, aldosterone in the highest tertile correlated with lower NP levels and increased mortality. Importantly, most of these associations remained significant even after excluding subjects with aldosterone levels above the normal range. In conclusion, we report that aldosterone is associated with hypertension, chronic kidney disease, obesity, metabolic syndrome, concentric left ventricular hypertrophy, and lower NPs in the general community. Our data suggest that aldosterone, even within the normal range, may be a biomarker of cardiorenal and metabolic disease. Further studies are warranted to evaluate a therapeutic and preventive strategy to delay the onset and progression of disease, using mineralocorticoid antagonists or chronic NP administration in high-risk subjects identified by plasma aldosterone.
Predictors for Glucose Change in Hypertensive Participants Following Short‐term Treatment with Atenolol or Hydrochlorothiazide
Study ObjectiveTo develop and validate a predictive model for glucose change and risk for new‐onset impaired fasting glucose in hypertensive participants following treatment with atenolol or hydrochlorothiazide (HCTZ).DesignRandomized multicenter clinical trial.PatientsA total of 735 white or African‐American men and women with uncomplicated hypertension.Measurements and Main ResultsPharmacogenomic Evaluation of Antihypertensive Responses (PEAR) is a randomized clinical trial to assess the genetic and nongenetic predictors of blood pressure response and adverse metabolic effects following treatment with atenolol or HCTZ. To develop and validate predictive models for glucose change, PEAR participants were randomly divided into a derivation cohort of 367 and a validation cohort of 368. Linear and logistic regression modeling were used to build models of drug‐associated glucose change and impaired fasting glucose (IFG), respectively, in the derivation cohorts. These models were then evaluated in the validation cohorts. For glucose change after atenolol or HCTZ treatment, baseline glucose was a significant (p<0.0001) predictor, explaining 13% of the variability in glucose change after atenolol and 12% of the variability in glucose change after HCTZ. Baseline glucose was also the strongest and most consistent predictor (p<0.0001) for development of IFG after atenolol or HCTZ monotherapy. The area under the receiver operating curve was 0.77 for IFG after atenolol and 0.71 after HCTZ treatment, respectively.ConclusionBaseline glucose is the primary predictor of atenolol or HCTZ‐associated glucose increase and development of IFG after treatment with either drug.