Lutecia Pereira

Common Breast Cancer-Predisposition Alleles Are Associated with Breast Cancer Risk in BRCA1 and BRCA2 Mutation Carriers

Germline mutations in BRCA1 and BRCA2 confer high risks of breast cancer. However, evidence suggests that these risks are modified by other genetic or environmental factors that cluster in families. A recent genome-wide association study has shown that common alleles at single nucleotide polymorphisms (SNPs) in FGFR2 (rs2981582), TNRC9 (rs3803662), and MAP3K1 (rs889312) are associated with increased breast cancer risks in the general population. To investigate whether these loci are also associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers, we genotyped these SNPs in a sample of 10,358 mutation carriers from 23 studies. The minor alleles of SNP rs2981582 and rs889312 were each associated with increased breast cancer risk in BRCA2 mutation carriers (per-allele hazard ratio [HR] = 1.32, 95% CI: 1.20-1.45, p(trend) = 1.7 x 10(-8) and HR = 1.12, 95% CI: 1.02-1.24, p(trend) = 0.02) but not in BRCA1 carriers. rs3803662 was associated with increased breast cancer risk in both BRCA1 and BRCA2 mutation carriers (per-allele HR = 1.13, 95% CI: 1.06-1.20, p(trend) = 5 x 10(-5) in BRCA1 and BRCA2 combined). These loci appear to interact multiplicatively on breast cancer risk in BRCA2 mutation carriers. The differences in the effects of the FGFR2 and MAP3K1 SNPs between BRCA1 and BRCA2 carriers point to differences in the biology of BRCA1 and BRCA2 breast cancer tumors and confirm the distinct nature of breast cancer in BRCA1 mutation carriers.

CD44 interacts with EGFR and promotes head and neck squamous cell carcinoma initiation and progression

OBJECTIVES CD44 is a promising target for therapy in head and neck squamous cell carcinoma (HNSCC) and has two defined roles in tumorigenesis: it is a cancer stem cell (CSC) marker and it promotes migration and proliferation through interaction with many signaling molecules. The purpose of this study was to investigate the role of CD44 in HNSCC carcinogenesis. MATERIALS AND METHODS The effects of CD44 in cell proliferation, migration, apoptosis and cisplatin resistance were studied by its overexpression in HNSCC cells. We also evaluated the effect of CD44 on tumor progression by siRNA methodology, immunohistochemistry (IHC) and western blot analysis. CD44 and EGFR colocalization were examined in CAL 27 cells by laser scanning confocal microscopy. The interaction between CD44 and EGFR was analyzed by immunoprecipation. RESULTS Overexpression of CD44 enhances cell proliferation and migration and correlates with increased cisplatin resistance and apoptosis inhibition in SCC25 cells. Downregulation of CD44 in CAL27 cells inhibited constitutive EGFR phosphorylation and significantly reduced tumor growth in nude mice. CD44 and EGFR colocalized in CAL 27 cells. CD44 coimmunoprecipated with EGFR in CAL 27 cells, indicating that these proteins interact with each other. CONCLUSION CD44 therapy in HNSCC may target the CSC population and alter EGFR signaling.

Salivary protein and solCD44 levels as a potential screening tool for early detection of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a devastating disease usually diagnosed at a late stage when cure rates are 40%. We examined a simple and inexpensive molecular tool that may aid HNSCC detection.

CHEK2:1100delC and female breast cancer in the United States.

Lutécia H. MATEUS PEREIRA, Alice J. SIGURDSON, Michele M. DOODY, Marbin A. PINEDA, Bruce H. ALEXANDER, Mark H. GREENE and Jeffery P. STRUEWING Laboratory of Population Genetics, National Cancer Institute, Bethesda, MD, USA Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD, USA Division of Environmental and Occupational Health, University of Minnesota, Minneapolis, MN, USA Clinical Genetics Branch, National Cancer Institute, Bethesda, MD, USA

Salivary markers and risk factor data: A multivariate modeling approach for head and neck squamous cell carcinoma detection

BACKGROUND Head and neck squamous cell carcinoma (HNSCC) is a debilitating and deadly disease largely due to late stage diagnosis. Prior work indicates that soluble CD44 (solCD44) and total protein may be useful diagnostic markers for HNSCC. In this study we combine the markers solCD44, IL-8, HA, and total protein with demographic and risk factor data to derive a multivariate logistic model that improves HNSCC detection as compared to our previous data using biomarkers alone. METHODS We performed the solCD44, IL-8, HA, and total protein assays on oral rinses from 40 HNSCC patients and 39 controls using ELISA assays. Controls had benign diseases of the upper aerodigestive tract and a history of tobacco or alcohol use. All subjects completed a questionnaire including demographic and risk factor data. RESULTS Depending on cancer subsite, differences between cases and controls were found for all markers. A multivariate logistic model including solCD44, total protein and variables related to smoking, oral health and education offered a significant improvement over the univariate models with an AUC of 0.853. Sensitivity ranged from 75-82.5% and specificity from 69.2-82.1% depending on predictive probability cut points. CONCLUSION A multivariate model, including simple and inexpensive molecular tests in combination with risk factors, results in a promising tool for distinguishing HNSCC patients from controls. IMPACT In this case-control study, the resulting observations led to an unprecedented multivariate model that distinguished HNSCC cases from controls with better accuracy than the current gold standard which includes oral examination followed by tissue biopsy. Since the components are simple, noninvasive, and inexpensive to obtain, this model combining biomarkers, risk factor and demographic data serves as a promising prototype for future cancer detection tests.

No association of TGFB1 L10P genotypes and breast cancer risk in BRCA1 and BRCA2 mutation carriers: a multi-center cohort study

Background The transforming growth factor β-1 gene (TGFB1) is a plausible candidate for breast cancer susceptibility. The L10P variant of TGFB1 is associated with higher circulating levels and secretion of TGF-β, and recent large-scale studies suggest strongly that this variant is associated with breast cancer risk in the general population. Methods To evaluate whether TGFB1 L10P also modifies the risk of breast cancer in BRCA1 or BRCA2 mutation carriers, we undertook a multi-center study of 3,442 BRCA1 and 2,095 BRCA2 mutation carriers. Results We found no evidence of association between TGFB1 L10P and breast cancer risk in either BRCA1 or BRCA2 mutation carriers. The per-allele HR for the L10P variant was 1.01 (95%CI: 0.92–1.11) in BRCA1 carriers and 0.92 (95%CI: 0.81–1.04) in BRCA2 mutation carriers. Conclusions These results do not support the hypothesis that TGFB1 L10P genotypes modify the risk of breast cancer in BRCA1 or BRCA2 mutation carriers.

Abstract 2521: Targeting CD44 in head and neck squamous cell carcinoma (HNSCC) with a new humanized antibody RO5429083

Introduction: HNSCC is a debilitating and deadly disease for which current treatments are extremely toxic and ineffective. Increasing data suggest that persistent cancer stem cells (CSC), resistant to standard chemo and radiation therapy, give rise to disease recurrence. Thus, poor outcomes may reflect ineffective CSC killing. CD44 is a promising therapeutic target that has two defined roles in tumorigenesis: it is a putative cancer initiating cell or CSC marker and it promotes migration and proliferation through interaction with EGFR, Rho and Ras signaling. Therefore therapies that target CD44 may destroy the CSC population, which is resistant to therapy while precisely eradicating the proliferating population of cancer cells. Methods: RO5429083 is a novel functional monoclonal antibody, developed by Roche, that targets a glycosylated, conformation dependent epitope of CD44. To evaluate CD44 as a therapeutic target in vivo, we established CAL 27 (HNSCC cell line) xenografts in nude mice and treated them with RO5429083 (Roche) in comparison to cisplatin (DPP), a conventional drug used in HNSCC treatment. After treatment, the mice were sacrificed, and the tumors were embedded in paraffin for IHC analysis. We also analyzed the effect of RO5429083 in vitro on peripheral blood lymphocytes (PBMCs). Results: RO5429083 treatment displayed a remarkable tumor growth inhibition in CAL 27 xenografts compared to DPP or control (P Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2521. doi:1538-7445.AM2012-2521

The BRCA1 Ashkenazi founder mutations occur on common haplotypes and are not highly correlated with anonymous single nucleotide polymorphisms likely to be used in genome-wide case-control association studies

BackgroundWe studied linkage disequilibrium (LD) patterns at the BRCA1 locus, a susceptibility gene for breast and ovarian cancer, using a dense set of 114 single nucleotide polymorphisms in 5 population groups. We focused on Ashkenazi Jews in whom there are known founder mutations, to address the question of whether we would have been able to identify the 185delAG mutation in a case-control association study (should one have been done) using anonymous genetic markers. This mutation is present in approximately 1% of the general Ashkenazi population and 4% of Ashkenazi breast cancer cases. We evaluated LD using pairwise and haplotype-based methods, and assessed correlation of SNPs with the founder mutations using Pearsons correlation coefficient.ResultsBRCA1 is characterized by very high linkage disequilibrium in all populations spanning several hundred kilobases. Overall, haplotype blocks and pair-wise LD bins were highly correlated, with lower LD in African versus non-African populations. The 185delAG and 5382insC founder mutations occur on the two most common haplotypes among Ashkenazim. Because these mutations are rare, even though they are in strong LD with many other SNPs in the region as measured by D-prime, there were no strong associations when assessed by Pearsons correlation coefficient, r (maximum of 0.04 for the 185delAG).ConclusionSince the required sample size is related to the inverse of r, this suggests that it would have been difficult to map BRCA1 in an Ashkenazi case-unrelated control association study using anonymous markers that were linked to the founder mutations.

Immunohistochemistry Analysis of CD44, EGFR, and p16 in Oral Cavity and Oropharyngeal Squamous Cell Carcinoma:

Objectives We analyze the relationship between CD44, epidermal growth factor receptor (EGFR), and p16 expression in oral cavity and oropharyngeal cancers in a diverse population. We also describe whether particular patterns of staining are associated with progression-free survival and overall survival. Study Design Prospective study, single-blind to pathologist and laboratory technologist. Setting Hospital based. Subjects and Methods Immunohistochemistry, comprising gross staining and cellular expression, was performed and interpreted in a blinded fashion on 24 lip/oral cavity and 40 oropharyngeal cancer specimens collected between 2007 and 2012 from participants of a larger study. Information on overall survival and progression-free survival was obtained from medical records. Results Nineteen cases were clinically p16 positive, 16 of which were oropharyngeal. Oral cavity lesions were more likely to exhibit strong CD44 membrane staining (P = .0002). Strong CD44 membrane and strong EGFR membrane and/or cytoplasmic staining were more common in p16-negative cancers (P = .006). Peripheral/mixed gross p16 staining pattern was associated with worse survival than the universal staining on univariate and multivariate analyses (P = .006, P = .030). This held true when combining gross and cellular localization for p16. For CD44, universal gross staining demonstrated poorer overall survival compared with the peripheral/mixed group (P = .039). CD44 peripheral/mixed group alone and when combined with universal p16 demonstrated the best survival on multivariate analysis (P = .010). Conclusion In a diverse population, systematic analysis applying p16, CD44, and EGFR gross staining and cellular localization on immunohistochemistry demonstrates distinct patterns that may have prognostic potential exceeding current methods. Larger studies are warranted to investigate these findings further.

Blocking the PAH2 domain of Sin3A inhibits tumorigenesis and confers retinoid sensitivity in triple negative breast cancer

Triple negative breast cancer (TNBC) frequently relapses locally, regionally or as systemic metastases. Development of targeted therapy that offers significant survival benefit in TNBC is an unmet clinical need. We have previously reported that blocking interactions between PAH2 domain of chromatin regulator Sin3A and the Sin3 interaction domain (SID) containing proteins by SID decoys result in EMT reversal, and re-expression of genes associated with differentiation. Here we report a novel and therapeutically relevant combinatorial use of SID decoys. SID decoys activate RARα/β pathways that are enhanced in combination with RARα-selective agonist AM80 to induce morphogenesis and inhibit tumorsphere formation. These findings correlate with inhibition of mammary hyperplasia and a significant increase in tumor-free survival in MMTV-Myc oncomice treated with a small molecule mimetic of SID (C16). Further, in two well-established mouse TNBC models we show that treatment with C16-AM80 combination has marked anti-tumor effects, prevents lung metastases and seeding of tumor cells to bone marrow. This correlated to a remarkable 100% increase in disease-free survival with a possibility of “cure” in mice bearing a TNBC-like tumor. Targeting Sin3A by C16 alone or in combination with AM80 may thus be a promising adjuvant therapy for treating or preventing metastatic TNBC.