Developmental Research Program
Jean-Pierre Issa, MD
Peter Jones, PhD
The specific objectives of the Developmental Research Program are to:
To achieve our aims, we will establish 1) specific criteria for selection and funding through a peer review mechanism, and 2) mechanisms for close monitoring of, and collaboration between the SPORE leaders and program awardees to enhance the quality of the translational research goals.
AWARDEES
Heather M. O'Hagan, PhD
Indiana University School of Medicine
Using epigenetic therapy to target enteroendocrine cells in mucinous colorectal cancer
Mucinous colorectal cancer (CRC) makes up 10-20% of total CRC and has distinct clinical features and molecular alterations from non-mucinous CRC. Responses of mucinous CRC to conventional chemotherapy are dramatically inferior when compared to non-mucinous CRC, resulting in a need for the development of new therapeutic approaches. We have determined that secretory enteroendocrine cells, in addition to goblet cells, are enriched in and drive mucinous BRAF mutant CRC. Our overall goal is to determine an epigenetic therapy approach for mucinous CRC that uses epigenetic inhibitors to target secretory cells and reduce tumorigenesis. To accomplish this goal, we will use our recently developed model of in situ mucinous BRAF mutant CRC to determine the effect of lysine demethylase 1 (LSD1) and DNA methyltransferase inhibition on tumor secretory cell content, the tumor immune microenvironment and colon tumorigenesis.
Roberto Pili, MD
University at Buffalo
Developing HDAC inhibitors as immunomodulators
Histone deacetylase (HDAC) inhibitors represent a class of agents with potential antitumor activity due to modulation of both transcriptional and non-transcriptional gene regulation. The goal of this project is to determine the immunomodulatory activity and therapeutic potential of HDAC inhibition in the setting of immunotherapies. We hypothesize that HDAC inhibition modulates the immune response and improves/restores the antitumor activity of immunotherapies. It is expected that these preclinical and clinical studies will provide: 1) Evidence that combining HDAC inhibitors and immunotherapies increases the antitumor effects 2) Insight on the role of HDACs in the modulation of specific immune cell subtypes 3) Foundation for future clinical trials in patients with renal cell carcinoma and other tumor types.
Cynthia A. Zahnow, PhD
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
Determination of the effectiveness of the dual G9a and DNMT inhibitor, CM272, in WT-TP53 and mutant TP53 ovarian cancers and the potential to re-sensitize PARP resistant ovarian cancers to PARP inhibition
Euchromatic histone-lysine N-methyltransferase 2 (EHMT2, also known as G9A) is a nuclear histone lysine methyltransferase that catalyzes H3K9me1 and H3K9me2 marks associated with transcriptional gene silencing. In addition to its role in histone methylation, G9A can methylate and inactivate the tumor suppressor protein, p53 (K373me2), but the role of this inactivation mechanism in cancer has not yet been extensively explored. Dr. Zahnow’s laboratory has preliminary evidence that CM272 is more effective in Trp53 WT vs.Trp53 mutant ovarian cancer and this one year project will seek to determine whether the mutational status of TP53 plays a role in regulating the effectiveness of the dual G9a/DNMT inhibitor, CM272 in ovarian cancer. We hypothesize that wildtype p53 protein in these tumors might be transcriptionally inactive as a result of G9a methylation. Therapeutic inhibition of G9a via CM272 in such tumors could therefore lead to p53 reactivation and cancer cell death.
G9A also promotes DNA damage repair via recruitment of BRCA1, 53BP1, and other factors involved in homologous recombination (HR) and non-homologous end joining (NHEJ). G9a is frequently amplified and overexpressed in ovarian cancers that are resistant to PARP inhibitors (PARPi), and high G9a expression correlates with aggressive peritoneal metastasis and poorer overall survival. Disruption or elimination of G9A in PARPi-resistant cells has been shown to re-sensitize tumor cells to PARPi. We hypothesize that CM272 may be able to re-sensitize resistant cells once again to PARP inhibitors. Our goal is to test CM272 in clinical trials for ovarian cancer within the next several years; and it is imperative that we determine whether p53 status plays a role in the effectiveness of CM272 and G9a inhibition. If so, p53 status and PARPi resistance may be key factors in patient selection.
