Faculty Summaries
Jeff Boyd, PhD
Jeff Boyd, PhD
Professor
  • Senior Vice President, Molecular Medicine
  • The Robert C. Young, MD, Chair in Cancer Research
  • Executive Director, Cancer Genome Institute
  • Chief, Division of Molecular Pathology
  • Professor, Cancer Biology Program
Jeff.Boyd@fccc.edu
Office Phone: 215-728-2907
Lab Phone: 215-214-4053
Office: R252
Lab: R354
  • Aneuploidy in Ovarian Tumorigenesis
    Eric Ariazi & John Taylor
    Aneuploidy in normal ovarian inclusion cysts
    Aneuploidy in normal ovarian inclusion cysts

    The high mortality rate associated with epithelial ovarian carcinoma (EOC) reflects diagnosis commonly at an advanced stage, but improved early detection is hindered by uncertainty as to the histologic origin and early natural history of this malignancy. Using combined molecular genetic and morphologic analyses of normal human ovarian tissues and early stage cancers, from both BRCA mutation carriers and the general population, we found that EOCs frequently arise from dysplastic precursor lesions within epithelial inclusion cysts. In pathologically normal ovaries, molecular evidence of oncogenic stress was observed specifically within epithelial inclusion cysts. To further explore potential very early events in ovarian tumorigenesis, ovarian tissues from women not known to be at high risk for ovarian cancer were subjected to laser catapult microdissection and gene expression profiling. These studies revealed a quasi-neoplastic expression signature in benign ovarian cystic inclusion epithelium compared to surface epithelium, specifically with respect to genes affecting signal transduction, cell cycle control, and mitotic spindle formation. Consistent with this gene expression profile, a significantly higher cell proliferation index (increased cell proliferation and decreased apoptosis) was observed in histopathologically normal ovarian cystic compared to surface epithelium. Furthermore, aneuploidy was frequently identified in normal ovarian cystic epithelium but not in surface epithelium. Together, these data indicate that EOC frequently arises in ovarian cystic inclusions, is preceded by an identifiable dysplastic precursor lesion, and that increased cell proliferation, decreased apoptosis, and aneuploidy are likely to represent very early aberrations in ovarian tumorigenesis. Current studies are designed to understand the relevance and mechanism of aneuploidy in early EOC precursor lesions.

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  • Role of MUC16 (CA125) in Ovarian Tumorigenesis
    Eric Ariazi & John Taylor

    The CA125 protein is a well-characterized blood marker for ovarian cancer and is used clinically to monitor response to therapy and recurrence of this malignancy. Recent identification of the gene encoding the CA125 protein revealed that it is a member of a family of proteins known as membrane-bound mucins, and the CA125-encoding gene was designated MUC16. The identification of MUC16 provides multiple new opportunities for a molecular genetic-based, mechanistic evaluation of the role of this molecule in ovarian neoplasia. The long-term goal of this project is to test the hypothesis that MUC16 plays a critical role in the development and/or maintenance of the malignant phenotype in ovarian cancer. This goal will be accomplished through a broad range of experimental approaches designed to gain insight into the function of MUC16 in normal development and cell biology, as well as in the neoplastic transformation of ovarian cells. Current work is designed to test whether a reduction of MUC16 levels in ovarian cancer cells affects the neoplastic phenotype. Using RNA interference, we will determine whether reduction of MUC16 mRNA levels in human ovarian cancer cells affects cell growth, differentiation, basement membrane invasion, anchorage-independent growth, and tumorigenicity in vivo.

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  • Estrogen Receptor-Mediated Gene Silencing in Tumorigenesis
    Eric Ariazi & John Taylor

    The broad objective of this project is to test the hypothesis that the activated estrogen receptor silences the expression of critical tumor suppressor genes, and further, to test whether this methylation-mediated gene silencing involves the recruitment of DNA methyl-transferases (DNMTs) and/or histone deacetylase (HDAC) proteins to the promoter regions of target genes. A substantial body of preliminary data has been generated to support these hypotheses. These objectives will be tested through five specific aims. Aim one will be to confirm that treatment of estrogen receptor (ER)-positive human breast cancer cells with estrogen results in the down-regulation of expression of the genes encoding lipocalin 2 (LCN2) and corticotropin releasing hormone (CRH). Aim two will be to determine whether this down-regulation of expression is associated with hypermethylation of the promoter regions of these two genes, to map the specific methylation sites, and to determine the time course of methylation in relation to gene silencing. Aim three with be to test whether this phenomenon is associated with the physical association of activated ER with DNMT1 and/or DNMT3B, and the physical association of HDAC1 with this complex in the promoter regions of LCN2 and CRH. Further, we will test whether deacetylation and methylation occur at H3-K9 in conjunction with these biophysical events. In aim four, RNAi approaches will be used to test whether knockdown of DNMTs prevents the ER-activation associated methylation and silencing of LCN2 and CRH. Finally, aim five will be to determine whether exposure of human breast cancer cells to recombinant LCN2 or CRH has a growth inhibitory or apoptotic effect, confirming the physiologic relevance of this phenomenon. These aims will be accomplished using standard techniques of cell culture, qRT-PCR, western blotting, real-time MS-PCR, bisulfite sequencing, chromatin immunoprecipitation (ChIP)-PCR, stable transfection of shRNA expression vectors, and cell proliferation and apoptosis assays.

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