Epidermal squamous cell carcinoma is one of the most common forms of human cancer and the incidence is increasing. Thus, skin cancer is an important health concern and advanced disease recurs and is life- threatening and disfiguring. Because skin cancer development involves multiple events over a long period of time, prevention is an important and preferred option. For this reason there is a major ongoing effort to identify preventive agents that can be taken orally or applied on the skin surface. In particula, we have focused on the impact of sulforaphane (SFN), derived from broccoli, on function of the Ezh2 Polycomb Group (PcG) protein. PcG proteins are important epigenetic regulators that methylate and ubiquitinate specific histones to produce closed chromatin and silence tumor suppressor gene expression. Key polycomb group proteins, including Ezh2, are overexpressed in skin cancer and this drives silencing of p21Cip1 and other tumor suppressors leading to enhanced tumor cell survival. We have shown that SFN suppresses Ezh2 which leads to increased p21Cip1 expression. These changes ultimately lead to cessation of skin cancer cell proliferation and increased cancer cell death. Our exciting unpublished preliminary studies suggest that a pathway that includes two master regulators of keratinocyte survival and stem cell fate, DNp63a and KLF4, regulates Ezh2 level. These proteins have not been previously considered as important prevention targets. We hypothesize that in cancer cells a DNp63a, KLF4 pathway stimulates Ezh2 gene expression which, in turn, acts to reduce p21Cip1 expression leading to increased cancer cell survival. We further propose that SFN inhibits events in this pathway to reduce Ezh2 expression and increase tumor suppressor expression. Experiments in this proposal revolve around well-defined translation-relevant goals.
Specific Aim 1 studies how DNp63a and KLF4 regulate Ezh2 level.
Specific Aims 2 examines SFN regulation of this pathway.
Specific Aim 3 examines Ezh2 regulation of p21Cip1 expression, and Specific Aim 4 address the impact of Ezh2 and SFN treatment on tumor formation in vivo. These studies are highly relevant to understanding the biological role of SFN in preventing skin cancer formation.

Public Health Relevance

Epidermal squamous cell carcinoma ranks among the most common forms of human cancer and is an important health concern. Because skin cancer develops over a long period of time, prevention is an important and preferred option to reduce skin cancer rate. Polycomb proteins are important epigenetic regulators of gene expression that are highly overexpressed in skin cancer and act to enhance skin cancer cell survival. In the present study we examine the mechanism whereby sulforaphane, a dietary agent derived from broccoli, reduces expression of polycomb group proteins leading to enhanced cancer cell death.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA131074-07
Application #
8689969
Study Section
Special Emphasis Panel (ZRG1-OTC-K (03))
Program Officer
Ross, Sharon A
Project Start
2007-12-01
Project End
2018-04-30
Budget Start
2014-05-01
Budget End
2015-04-30
Support Year
7
Fiscal Year
2014
Total Cost
$413,155
Indirect Cost
$143,998
Name
University of Maryland Baltimore
Department
Biochemistry
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Grun, D; Adhikary, G; Eckert, R L (2016) VEGF-A acts via neuropilin-1 to enhance epidermal cancer stem cell survival and formation of aggressive and highly vascularized tumors. Oncogene 35:4379-87
Fisher, Matthew L; Kerr, Candace; Adhikary, Gautam et al. (2016) Transglutaminase Interaction with α6/β4-Integrin Stimulates YAP1-Dependent ΔNp63α Stabilization and Leads to Enhanced Cancer Stem Cell Survival and Tumor Formation. Cancer Res 76:7265-7276
Kerr, C; Szmacinski, H; Fisher, M L et al. (2016) Transamidase site-targeted agents alter the conformation of the transglutaminase cancer stem cell survival protein to reduce GTP binding activity and cancer stem cell survival. Oncogene :
Fisher, Matthew L; Adhikary, Gautam; Grun, Dan et al. (2016) The Ezh2 polycomb group protein drives an aggressive phenotype in melanoma cancer stem cells and is a target of diet derived sulforaphane. Mol Carcinog 55:2024-2036
Saha, Kamalika; Adhikary, Gautam; Eckert, Richard L (2016) MEP50/PRMT5 Reduces Gene Expression by Histone Arginine Methylation and this Is Reversed by PKCδ/p38δ Signaling. J Invest Dermatol 136:214-24
Rorke, Ellen A; Adhikary, Gautam; Young, Christina A et al. (2015) Suppressing AP1 factor signaling in the suprabasal epidermis produces a keratoderma phenotype. J Invest Dermatol 135:170-80
Balasubramanian, Sivaprakasam; Scharadin, Tiffany M; Han, Bingshe et al. (2015) The Bmi-1 helix-turn and ring finger domains are required for Bmi-1 antagonism of (-) epigallocatechin-3-gallate suppression of skin cancer cell survival. Cell Signal 27:1336-44
Fisher, Matthew L; Keillor, Jeffrey W; Xu, Wen et al. (2015) Transglutaminase Is Required for Epidermal Squamous Cell Carcinoma Stem Cell Survival. Mol Cancer Res 13:1083-94
Eckert, Richard L; Fisher, Matthew L; Grun, Dan et al. (2015) Transglutaminase is a tumor cell and cancer stem cell survival factor. Mol Carcinog 54:947-58
Adhikary, Gautam; Grun, Daniel; Balasubramanian, Sivaprakasam et al. (2015) Survival of skin cancer stem cells requires the Ezh2 polycomb group protein. Carcinogenesis 36:800-10

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