Abnormal Mammary Gland Development and Growth Retardation in Female Mice and MCF7 Breast Cancer Cells Lacking Androgen Receptor

Phenotype analysis of female mice lacking androgen receptor (AR) deficient (AR−/−) indicates that the development of mammary glands is retarded with reduced ductal branching in the prepubertal stages, and fewer Cap cells in the terminal end buds, as well as decreased lobuloalveolar development in adult females, and fewer milk-producing alveoli in the lactating glands. The defective development of AR−/− mammary glands involves the defects of insulin-like growth factor I–insulin-like growth factor I receptor and mitogen-activated protein kinase (MAPK) signals as well as estrogen receptor (ER) activity. Similar growth retardation and defects in growth factor–mediated Ras/Raf/MAPK cascade and ER signaling are also found in AR−/− MCF7 breast cancer cells. The restoration assays show that AR NH2-terminal/DNA-binding domain, but not the ligand-binding domain, is essential for normal MAPK function in MCF7 cells, and an AR mutant (R608K), found in male breast cancer, is associated with the excessive activation of MAPK. Together, our data provide the first in vivo evidence showing that AR-mediated MAPK and ER activation may play important roles for mammary gland development and MCF7 breast cancer cell proliferation

Are C-Reactive Protein Associated Genetic Variants Associated with Serum Levels and Retinal Markers of Microvascular Pathology in Asian Populations from Singapore?

Introduction:C-reactive protein (CRP) levels are associated with cardiovascular disease and systemic inflammation. We assessed whether CRP-associated loci were associated with serum CRP and retinal markers of microvascular disease, in Asian populations.Methods:Genome-wide association analysis (GWAS) for serum CRP was performed in East-Asian Chinese (N = 2,434) and Malays (N = 2,542) and South-Asian Indians (N = 2,538) from Singapore. Leveraging on GWAS data, we assessed, in silico, association levels among the Singaporean datasets for 22 recently identified CRP-associated loci. At loci where directional inconsistencies were observed, quantification of inter-ethnic linkage disequilibrium (LD) difference was determined. Next, we assessed association for a variant at CRP and retinal vessel traits [central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE)] in a total of 24,132 subjects of East-Asian, South-Asian and European ancestry.Results:Serum CRP was associated with SNPs in/near APOE, CRP, HNF1A and LEPR (p-values ≤4.7×10-8) after meta-analysis of Singaporean populations. Using a candidate-SNP approach, we further replicated SNPs at 4 additional loci that had been recently identified to be associated with serum CRP (IL6R, GCKR, IL6 and IL1F10) (p-values ≤0.009), in the Singaporean datasets. SNPs from these 8 loci explained 4.05% of variance in serum CRP. Two SNPs (rs2847281 and rs6901250) were detected to be significant (p-value ≤0.036) but with opposite effect directions in the Singaporean populations as compared to original European studies. At these loci we did not detect significant inter-population LD differences. We further did not observe a significant association between CRP variant and CRVE or CRAE levels after meta-analysis of all Singaporean and European datasets (p-value >0.058).Conclusions:Common variants associated with serum CRP, first detected in primarily European studies, are also associated with CRP levels in East-Asian and South-Asian populations. We did not find a causal link between CRP and retinal measures of microvascular disease

Retinoid-Induced Expression and Activity of an Immediate Early Tumor Suppressor Gene in Vascular Smooth Muscle Cells

Retinoids are used clinically to treat a number of hyper-proliferative disorders and have been shown in experimental animals to attenuate vascular occlusive diseases, presumably through nuclear receptors bound to retinoic acid response elements (RARE) located in target genes. Here, we show that natural or synthetic retinoids rapidly induce mRNA and protein expression of a specific isoform of A-Kinase Anchoring Protein 12 (AKAP12β) in cultured smooth muscle cells (SMC) as well as the intact vessel wall. Expression kinetics and actinomycin D studies indicate Akap12β is a retinoid-induced, immediate-early gene. Akap12β promoter analyses reveal a conserved RARE mildly induced with atRA in a region that exhibits hyper-acetylation. Immunofluorescence microscopy and protein kinase A (PKA) regulatory subunit overlay assays in SMC suggest a physical association between AKAP12β and PKA following retinoid treatment. Consistent with its designation as a tumor suppressor, inducible expression of AKAP12β attenuates SMC growth in vitro. Further, immunohistochemistry studies establish marked decreases in AKAP12 expression in experimentally-injured vessels of mice as well as atheromatous lesions in humans. Collectively, these results demonstrate a novel role for retinoids in the induction of an AKAP tumor suppressor that blocks vascular SMC growth thus providing new molecular insight into how retiniods may exert their anti-proliferative effects in the injured vessel wall

Interaction among apoptosis-associated sequence variants and joint effects on aggressive prostate cancer

<p>Abstract</p> <p>Background</p> <p>Molecular and epidemiological evidence demonstrate that altered gene expression and single nucleotide polymorphisms in the apoptotic pathway are linked to many cancers. Yet, few studies emphasize the interaction of variant apoptotic genes and their joint modifying effects on prostate cancer (PCA) outcomes. An exhaustive assessment of all the possible two-, three- and four-way gene-gene interactions is computationally burdensome. This statistical conundrum stems from the prohibitive amount of data needed to account for multiple hypothesis testing.</p> <p>Methods</p> <p>To address this issue, we systematically prioritized and evaluated individual effects and complex interactions among 172 apoptotic SNPs in relation to PCA risk and aggressive disease (i.e., Gleason score ≥ 7 and tumor stages III/IV). Single and joint modifying effects on PCA outcomes among European-American men were analyzed using statistical epistasis networks coupled with multi-factor dimensionality reduction (SEN-guided MDR). The case-control study design included 1,175 incident PCA cases and 1,111 controls from the prostate, lung, colo-rectal, and ovarian (PLCO) cancer screening trial. Moreover, a subset analysis of PCA cases consisted of 688 aggressive and 488 non-aggressive PCA cases. SNP profiles were obtained using the NCI Cancer Genetic Markers of Susceptibility (CGEMS) data portal. Main effects were assessed using logistic regression (LR) models. Prior to modeling interactions, SEN was used to pre-process our genetic data. SEN used network science to reduce our analysis from > 36 million to < 13,000 SNP interactions. Interactions were visualized, evaluated, and validated using entropy-based MDR. All parametric and non-parametric models were adjusted for age, family history of PCA, and multiple hypothesis testing.</p> <p>Results</p> <p>Following LR modeling, eleven and thirteen sequence variants were associated with PCA risk and aggressive disease, respectively. However, none of these markers remained significant after we adjusted for multiple comparisons. Nevertheless, we detected a modest synergistic interaction between <it>AKT3 rs2125230-PRKCQ rs571715 </it>and disease aggressiveness using SEN-guided MDR (p = 0.011).</p> <p>Conclusions</p> <p>In summary, entropy-based SEN-guided MDR facilitated the logical prioritization and evaluation of apoptotic SNPs in relation to aggressive PCA. The suggestive interaction between <it>AKT3-PRKCQ </it>and aggressive PCA requires further validation using independent observational studies.</p

Polygenic Risk Scores for Prediction of Breast Cancer and Breast Cancer Subtypes

Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57-1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628-0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs.NovartisEli Lilly and CompanyAstraZenecaAbbViePfizer UKCelgeneEisaiGenentechMerck Sharp and DohmeRocheCancer Research UKGovernment of CanadaArray BioPharmaGenome CanadaNational Institutes of HealthEuropean CommissionMinistère de l'Économie, de l’Innovation et des Exportations du QuébecSeventh Framework ProgrammeCanadian Institutes of Health Researc

Genome-wide association study of germline variants and breast cancer-specific mortality

AbstractBackground: We examined the associations between germline variants and breast cancer mortality using a large meta-analysis of women of European ancestry.Methods: Meta-analyses included summary estimates based on Cox models of twelve datasets using ~10.4 million variants for 96,661 women with breast cancer and 7697 events (breast cancer-specific deaths). Oestrogen receptor (ER)-specific analyses were based on 64,171 ER-positive (4116) and 16,172 ER-negative (2125) patients. We evaluated the probability of a signal to be a true positive using the Bayesian false discovery probability (BFDP).Results: We did not find any variant associated with breast cancer-specific mortality at P −8. For ER-positive disease, the most significantly associated variant was chr7:rs4717568 (BFDP = 7%, P = 1.28 × 10−7, hazard ratio [HR] = 0.88, 95% confidence interval [CI] = 0.84–0.92); the closest gene is AUTS2. For ER-negative disease, the most significant variant was chr7:rs67918676 (BFDP = 11%, P = 1.38 × 10−7, HR = 1.27, 95% CI = 1.16–1.39); located within a long intergenic non-coding RNA gene (AC004009.3), close to the HOXA gene cluster.Conclusions: We uncovered germline variants on chromosome 7 at BFDP Abstract Background: We examined the associations between germline variants and breast cancer mortality using a large meta-analysis of women of European ancestry. Methods: Meta-analyses included summary estimates based on Cox models of twelve datasets using ~10.4 million variants for 96,661 women with breast cancer and 7697 events (breast cancer-specific deaths). Oestrogen receptor (ER)-specific analyses were based on 64,171 ER-positive (4116) and 16,172 ER-negative (2125) patients. We evaluated the probability of a signal to be a true positive using the Bayesian false discovery probability (BFDP). Results: We did not find any variant associated with breast cancer-specific mortality at P < 5 × 10−8. For ER-positive disease, the most significantly associated variant was chr7:rs4717568 (BFDP = 7%, P = 1.28 × 10−7, hazard ratio [HR] = 0.88, 95% confidence interval [CI] = 0.84–0.92); the closest gene is AUTS2. For ER-negative disease, the most significant variant was chr7:rs67918676 (BFDP = 11%, P = 1.38 × 10−7, HR = 1.27, 95% CI = 1.16–1.39); located within a long intergenic non-coding RNA gene (AC004009.3), close to the HOXA gene cluster. Conclusions: We uncovered germline variants on chromosome 7 at BFDP < 15% close to genes for which there is biological evidence related to breast cancer outcome. However, the paucity of variants associated with mortality at genome-wide significance underpins the challenge in providing genetic-based individualised prognostic information for breast cancer patients

Abstract 452: Serine Carboxypeptidase 1 Mediates Vascular Remodeling by Increasing Inflammatory Cell Infiltration

In pathological vascular remodeling, contractile vascular smooth muscle cells (VSMCs) switch their phenotype to highly proliferative and migratory states leading to neointimal formation. Inflammatory cell recruitment and infiltration, which is dependent on the increased expression of adhesion molecules on the endothelial cells, is a key event to initiate SMC phenotypic modulation in vascular remodeling. Serine carboxypeptidase 1 (scpep1), a novel protease containing the putative catalytic triad (Ser-Asp-His) common to all members of the serine protease family, has been proved to be involved in vascular remodeling by promoting SMC proliferation and migration in a catalytic triad-dependent manner. To determine whether Scpep1 modulates leukocyte adhesion and infiltration, a flow-induced model of vascular remodeling was conducted in wild-type (WT) or Scpep1 knockout (KO) mice. Scpep1-null mice show a decreased number of infiltrated leukocytes into the intima and media compared to WT mice. Further, mice devoid of Scpep1 show a dramatic reduction of vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) expression in vessels in comparison with that of WT mice. Consistent with our in vivo data, the expression levels of ICAM-1 and VCAM-1 on human umbilical vein endothelial cells (HUVECs) transfected with SiRNA against Scpep1 were significantly decreased after TNF-α treatment. Taken together, these data suggest that Scpep1 may increase leukocyte extravasation by increasing the expression of VCAM-1 and ICAM-1 adhesion molecules.</jats:p

Abstract 512: Collagen Homologous Sequence R1R2 Mediates Vascular Remodeling by Decreasing Inflammation and Smooth Muscle Proliferation

The extracellular matrix (ECM) is a major constituent of the vessel wall. Except for providing a structural scaffold for cells, ECM controls numerous cellular functions like adhesion, growth, migration and differentiation. The components of ECM are mediated by the interplay between ECM synthesis, deposition, degradation and the interaction between ECM proteins. Vascular remodeling occurs in the vascular diseases and is characterized by endothelial cell activation, inflammatory cell infiltration, smooth muscle cell (SMC) proliferation/migration, and augmented deposition of ECM proteins. Collagen I is the major ECM component in the arterial wall, excess collagen I accumulation may exacerbate the vascular disease by further facilitating SMC proliferation/migration. Therefore, treatments to inhibit excess collagen deposition could provide a remedy for vascular disease. R1R2, a peptide derived from the bacterial adhesin SFS with sequence homology to collagen, is known to inhibit collagen I deposition by inhibiting the binding of fibronectin to collagen. Studies have revealed that R1R2 affects collagen I-dependent cell growth and migration in vitro. However, the in vivo functions of R1R2 during vascular remodeling remain unknown. We hypothesized that R1R2 prevents excess collagen I accumulation and SMC proliferation, resulting in decreased neointimal formation. We induced vascular remodeling by ligating the carotid artery on mice. Delivery of R1R2 was periadventially applied using pluronic gel and evaluated its effects on vascular remodeling, ECM deposition, SMC proliferation and differentiation. Morphometric analysis demonstrated that R1R2 reduced intima-media thickening by 50% compared to the control group. R1R2 treatment also decreased collagen I deposition in the vessel wall and maintained SMC in the contractile phenotype. Interestingly, R1R2 dramatically reduced inflammatory cell infiltration into the vessel by 80% accompanied with decreased VCAM-1 and ICAM-1. In conclusion, our data showed that R1R2 attenuates the vascular remodeling response by decreasing inflammation and SMC proliferation/migration. These studies provide a therapeutic potential of periadventitially delivering R1R2 in treating vascular diseases.</jats:p

Expression and Functional Characterization of a Novel Putative Serine Carboxypeptidase in Vascular Smooth Muscle Cells

Thesis (Ph.D.)--University of Rochester. School of Medicine and Dentistry. Dept. of Pathology and Laboratory Medicine, 2008.A number of proteases have been shown to alter vascular smooth muscle cell proliferation and migration thus contributing to a variety of vascular disorders. We previously identified from cultured vascular smooth muscle cells (SMC) a novel gene designated retinoid-inducible serine carboxypeptidase (RISC). However, subsequent work indicated the induction of RISC by retinoids was incidental. As a result, we refer to RISC herein as serine carboxypeptidase 1 (SCPEP1), the Human Genome Organization (HUGO) approved gene name. SCPEP1 bears the signature catalytic triad found in all serine carboxypeptidases in nature, but nothing is known as to its function. In this thesis, I have characterized SCPEP1’s distribution and biological activities in vitro and in vivo with special emphasis on vascular SMC. We demonstrate that SCPEP1 is abundantly expressed in a variety of organ systems from the embryonic stage to adulthood. We further show that 55-kDa full-length SCPEP1 is cleaved into a 35-kDa fragment that accumulates inside the lysosomal compartment. Subsequently, we find SCPEP1 is highly expressed in the neointima after ligation injury where SMC continue to display cell cycle activity, migratory ability or remodeling. To evaluate the functional role of SCPEP1 in cultured vascular SMC, adenoviral-mediated overexpression of SCPEP1 is shown to promote vascular SMC proliferation and migration in vitro. Such effects are abolished with either a short hairpin RNA to Scpep1 or catalytic triad mutant (S167A) Scpep1. Silent mutations in SCPEP1 that evade Scpep1 RNA knockdown completely rescue the growth- and migration-inducing effects. In addition, I discovered a mutant SCPEP1 that doesn’t undergo cleavage, but still works in pro-growth and pro-migration effects, suggesting that cleavage of SCPEP1 is not necessary for mediating SMC growth and migration. To evaluate SCPEP1 function in vivo, I generated a knockout mouse. Scpep1-/- mice are viable and fertile with no obvious abnormalities. However, Scpep1-/- mice exhibit significantly decreased vascular remodeling. Collectively, my dissertation data suggest that SCPEP1 promotes vascular SMC proliferation and migration in a catalytic triad-dependent, cleavage-independent manner. SCPEP1 may therefore represent a new therapeutic target for the treatment of vascular occlusive diseases in the future