Citations

Abstract Introduction: We recently reported the percentage of mammographic density (MD) to be a breast cancer risk factor across tumor characteristics and age groups. Yet, we noted stronger associations for tumors of large size and positive lymph nodes across all ages, and ER-negative status among women ages <55 years, suggesting high MD may play an important role in tumor aggressiveness, especially in younger women. We extend this initial study to investigate whether these associations with aggressive disease are due to the underlying associations of absolute dense or non-dense area, or both, with breast cancer risk. Methods: Data were pooled from six studies including 3517 women with invasive breast cancer and 8558 without. Dense area and non-dense area were assessed from digitized film-screen mammograms using a computer-assisted threshold technique. We standardized dense and non-dense area measurements made within each study and categorized into quartiles based on the control distribution for pooled analyses. We used polytomous logistic regression to calculate breast cancer odds according to tumor type, histopathological characteristics, and receptor (ER, PR) status by age (<55, 55-64, and ≥65 years), adjusting for continuous age, body mass index, and study site. Results: Absolute dense area was associated with increased breast cancer risk [odds ratios (ORs) Q1 vs Q2: 0.67, Q3 vs Q2: 1.25, Q4 vs Q2: 1.62] and non-dense area was associated with decreased breast cancer risk (ORs: Q1 vs Q2: 1.44, Q3 vs Q2: 0.89, Q4 vs Q2: 0.71) overall and across all age groups. Positive associations for absolute dense area were observed across all invasive tumor characteristics. Stronger associations were noted for larger tumors across all ages (p-trend <0.01). Among women <55 years, stronger associations were observed for ER+ vs ER- [p-heterogeneity (het) = 0.02] and PR+ vs PR- tumors (p-het = 0.02). Non-dense area was inversely associated with all tumor characteristics evaluated except for tumors <1.1 cm, for which no association was present. The inverse association was stronger for larger tumors, particularly for women <55 years (p-trend <0.01). Also among women <55 years, a stronger inverse association with non-dense area was observed for ER- vs. ER+ tumors (p-het = 0.02). Conclusion: These results suggest the strong association we previously observed of high percent MD and ER-negative disease in women <55 years could be explained by the low amount of non-dense area in these women. Further research is warranted to clarify the possible differential associations of absolute dense and non-dense area on breast cancer risk according to tumor characteristics. Citation Format: Kimberly A. Bertrand, Christopher G. Scott, Rulla M. Tamimi, Matthew R. Jensen, V. Shane Pankratz, Aaron Norman, John Shepherd, Yunn-Yi Chen, Karla Kerlikowske, Celine M. Vachon. Dense and non-dense mammographic area and risk of breast cancer by age and tumor characteristics. [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 3279. doi:10.1158/1538-7445.AM2014-3279

Abstract Metastatic invasion of tumors into peripheral tissues is known to rely upon protease-mediated degradation of the surrounding stroma. This remodeling process is dependent upon complex, actin-based specializations of the plasma membrane termed “invadopodia” that act to both sequester and release matrix metalloproteases. Here we report that cells of mesenchymal origin, including fibroblasts, pancreatic stellate cells, and tumor-associated fibroblasts, degrade substantial amounts of surrounding matrix by a mechanism independent of conventional invadopodia. First, as tumor cell-derived invadopodia are dependent upon the action of the GTPase Dyn2, loss of Dyn2 function inhibits invadopodia-based matrix degradation by pancreatic tumor cells. In surprising contrast, we have found that loss of Dyn2 function in mesenchymal cells does not inhibit degradation, but actually leads to a marked increase. Second, these degradative sites lack the punctate shape of conventional invadopodia but are instead spread along the cell base and are reticular and/or fibrous in character. Third, inhibition of either Src or Cdc42 function, known to drive invadopodia formation, had no effect on the mesenchymal matrix degradation induced by loss of Dyn2. Taken together, these data indicate that this mechanism of degradation is independent of classical invadopodial degradation. To define the mechanistic processes that differ between tumor and stromal cell types, we screened for matrix metalloprotease activity using zymography. An unexpected and significant upregulation of MMP2 activity in mesenchymal-derived cells upon loss of Dyn2 was observed, whereas MMP2 was nearly completely absent in the tumor cells. Further, loss of Dyn2 resulted in an upregulation of surface-bound MT1-MMP, known to activate MMP2. In contrast, loss of Dyn2 in the pancreatic tumor cells reduced surface levels of MT1-MMP. Thus, in mesenchymal cells, loss of Dyn2 induces retention of MT1-MMP at the surface, leading to large scale matrix degradation through an MT1-MMP/MMP2-dependent mechanism. Excitingly, co-culture invasion experiments demonstrate that the matrix degradation induced in these stromal fibroblasts is sufficient to promote invasion by pancreatic tumor cells. These findings provide evidence for a novel matrix remodeling process conducted by mesenchymal cells that is substantially more effective than conventional invadopodia, distinct in structural organization, independent of the classical invadopodial machinery, and capable of promoting invasion by pancreatic tumor cells. Supported by NCI RO1 CA104125 to MAM. Citation Format: Hong Cao, Robbin Eppinga, Eugene Krueger, Jing Chen, Gina Razidlo, Mark A. McNiven. Differential mechanisms utilized by pancreatic tumor cells and associated fibroblasts to remodel stroma during metastatic invasion. [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 3162. doi:10.1158/1538-7445.AM2014-3162

Abstract Dysregulation of the intrinsic DNA methylation landscape is a ubiquitous feature of human carcinogenesis, manifested by global hypomethylation and promoter-specific hypermethylation, ultimately resulting in genome instability and tumor suppressor gene silencing, respectively. Alterations in DNA methylation are particularly apparent in hepatocellular carcinoma (HCC) which afflicts roughly 750,000 new patients each year [1]. Indeed, it has been demonstrated that a variety of tumor suppressor genes (e.g. p53, E-cadherin) are hypermethylated and silenced in HCC [2-4]. Importantly, HCC is accompanied by the premalignant stage of cirrhosis in 80% of cases. One major roadblock to understanding the methylome in HCC is the presence of multiple etiologies such as Hepatitis C virus (HCV), Hepatitis B virus (HBV), and chronic alcoholism. Therefore, we performed genome-wide methylation profiling to dissect the methylation patterns of more than 170 primary liver samples to stratify etiologic and stage-specific changes in the DNA methylation landscape. Our results profile the DNA methylation landscape across normal, cirrhotic, and HCC livers in the largest study of its kind to date. We unveil distinct locus-specific and large-scale effects of HCV, HBV, and chronic alcoholism in hepatocarcinogenesis. Furthermore, analysis indicates a specific methylation profile for individual etiologies as well as conserved patterns throughout cirrhosis and hepatocellular carcinoma. Our study demonstrates that each etiology contains potential biomarkers and targets for downstream clinical therapeutics. This study is our first step toward defining the epigenome in cirrhosis and hepatocellular carcinoma and will be combined with future genomic and epimutational data (e.g. transcription, histone modifications, miRNA) to determine the true extent and interplay between epigenetic marks across different stages of liver cancer. Overall, this research has the potential to improve our understanding of epigenetics and result in diagnostic, prognostic, and therapeutic epigenetic signatures in cirrhosis and hepatocellular carcinoma, which are expected to allow for more timely and efficient detection of disease. 1. Jemal, A., et al., Global cancer statistics. CA: a cancer journal for clinicians, 2011. 61(2): p. 69-90. 2. Tischoff, I. and A. Tannapfe, DNA methylation in hepatocellular carcinoma. World journal of gastroenterology : WJG, 2008. 14(11): p. 1741-8. 3. Calvisi, D.F., et al., Mechanistic and prognostic significance of aberrant methylation in the molecular pathogenesis of human hepatocellular carcinoma. The Journal of clinical investigation, 2007. 117(9): p. 2713-22. 4. Lambert, M.P., et al., Aberrant DNA methylation distinguishes hepatocellular carcinoma associated with HBV and HCV infection and alcohol intake. Journal of hepatology, 2011. 54(4): p. 705-15. Citation Format: Ryan A. Hlady, Rochelle Tiedemann, William Puszyk, Chen Liu, Jeong-Hyeon Choi, Keith D. Robertson. Identification of common and unique epigenetic signatures of chronic hepatitis infection and alcohol abuse in human liver disease. [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 2309. doi:10.1158/1538-7445.AM2014-2309

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.

ABSTRACTBACKGROUNDDisability progression in multiple sclerosis (MS) remains incompletely understood. Unlike lesional measures, central nervous system atrophy has a strong correlation with disability. Theiler's murine encephalomyelitis virus infection in SJL/J mice is an established model of progressive MS. We utilized in vivo MRI to quantify brain and spinal cord atrophy in this model and analyzed the temporal relationship between atrophy and disability.METHODSInfected and control mice were followed for 12 months. Disability was assessed periodically using rotarod assay. Volumetric MRI datasets were acquired at 7 Tesla. Ventricular volume and C4‐5 spinal cord cross‐sectional area measurements were performed using Analyze 10.RESULTSAt 3 months, brain atrophy reached statistical significance (P = .005). In contrast, disability did not differ until 4 months post‐infection (P = .0005). Cord atrophy reached significance by 9 months (P = 0.009). By 12 months, brain atrophy resulted in 111.8% increased ventricular volume (P = .00003), while spinal cord cross‐sectional area was 25.6% reduced (P = .001) among cases.CONCLUSIONSOur results suggest that significant brain atrophy precedes and predicts the development of disability, while spinal cord atrophy occurs late and correlates with severe disability. The observed temporal relationship establishes a framework for mechanisms of disability progression and enables further investigations of their underlying substrate.

ObjectivesWe tested the hypothesis that a common functional variant in brain‐derived neurotrophic factor (BDNF), Val66Met, which has been shown to be associated with increased body mass index (BMI) in schizophrenia (SCZ) and schizoaffective disorder (SAD), is also associated with antipsychotic‐induced weight gain in bipolar disorder (BPD). Association of Val66Met with other metabolic measures, including high‐ and low‐density cholesterol, triglycerides, total cholesterol, fasting blood glucose, and hemoglobin A1c, was also tested.MethodsThis was a 12‐month, prospective, randomized trial of two atypical antipsychotic drugs (APDs) with moderate (risperidone) or high (olanzapine) risk to cause weight gain. Subjects were diagnosed as having BPD (n = 90) and SCZ or SAD (n = 76).ResultsBMI was significantly greater in all diagnoses for Met66 allele carriers at six months (p = 0.01). Met66 carriers with BPD showed a greater increase in the triglycerides/high‐density (HDL) cholesterol ratio (p = 0.01), a key marker for metabolic syndrome related to insulin resistance, and log‐triglycerides (p = 0.04), after three or six months of treatment. Met66 carriers had the greatest increase in log‐triglycerides (p = 0.03) and triglycerides/HDL cholesterol ratio after three months of treatment with risperidone (p = 0.003), and the highest BMI at six months (p = 0.01).ConclusionsThe positive association of BNDF Val66Met with high BMI values replicates previous findings in patients with SCZ and indicates the BDNF Val66Met genotype as a potential risk factor for obesity and insulin resistance measures in patients with BPD receiving antipsychotics as well.

Background— Early studies showed beneficial effects of phosphodiesterase 5 inhibitors on cardiovascular function in heart failure (HF) patients, but the RELAX trial observed no improvement in exercise capacity with sildenafil treatment in subjects with HF and preserved ejection fraction. Methods and Results— A subgroup of participants in the RELAX trial (n=48) underwent comprehensive noninvasive cardiovascular assessment before and after treatment with sildenafil or placebo in a prospective ancillary study. Left ventricular contractility was assessed by peak power index and stroke work index. Systemic arterial load was assessed by arterial elastance (Ea) and right ventricular afterload by pulmonary artery systolic pressure. Endothelial function was assessed by reactive hyperemia index after upper arm cuff occlusion. Compared with placebo (n=25), sildenafil (n=23) decreased Ea (−0.29±0.28 mm Hg/mL versus +0.02±0.29, P =0.008) and tended to improve reactive hyperemia index (+0.30±0.45 versus −0.17±0.30, P =0.054). In contrast, left ventricular contractility was reduced by 11% to 16% with sildenafil compared with placebo (ΔPWR/EDV −52±70 versus +0±40 mm Hg/s, P =0.006; ΔSW/EDV +0.3±5.8 versus −6.0±5.1 mm Hg, P =0.04). Sildenafil had no effect on pulmonary artery systolic pressure. Conclusions— In subjects with HF and preserved ejection fraction, sildenafil displayed opposing effects on ventricular and vascular function. We speculate that beneficial effects of phosphodiesterase 5 inhibitors in the systemic vasculature and endothelium were insufficient to improve clinical status or that the deleterious effects on left ventricular function offset any salutary vascular effects, contributing to the absence of benefit observed with sildenafil in subjects with HF and preserved ejection fraction in the RELAX trial. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00094302.