Skin cancer is the most common cancer in the US and worldwide with a continually increasing incidence 22,23. Exposure to ultraviolet B radiation (UVB) from the sun is the major environmental risk factor causing skin cancer. In addition to causing DNA damage and increased mutation burden, UVB also causes the inflammatory damage response, which can also contribute to tumorigenesis. In the past decades, tremendous progress has been made in elucidating the mechanism of skin cancer development, including the role of inflammation. However, our understanding of the molecular mechanism regulating UVB damage response and skin cancer is still limited. Recently, we have discovered a novel role of YTHDF2, an N6-methyladenosine (m6A) RNA methylation reader, as an autophagy target, in suppressing UVB-induced inflammation and tumor growth. m6A RNA methylation is the most abundant internal chemical modification in eukaryotic messenger RNA (mRNA) as well as non-coding RNA (ncRNA). m6A modification regulates the fate of RNA and its functions, such as RNA stability, translation, nuclear processing, and RNA-protein interactions. Guided by our preliminary data and published work, we hypothesize that YTHDF2, as an m6A reader, suppresses UVB-induced damage response and skin tumorigenesis through post-transcriptionally regulating RNA stability. To test this hypothesis, we will employ several new methods including transcriptome-wide m6A mapping, eCLIP-seq, and RIP-seq, as well as a new mouse model with skin-specific YTHDF2 deletion. Our hypothesis will be tested in three Specific Aims.
Aim 1 will determine the mechanism by which YTHDF2 regulates UVB damage response and tumorigenicity.
Aim 2 will determine the mechanism by which UVB down-regulates YTHDF2 through autophagy.
Aim 3 will determine the consequences of YTHDF2 inhibition in UVB damage response and skin tumorigenesis using mice with keratinocyte-specific deletion of YTHDF2. Successful completion of our proposed work will vastly expand our knowledge on the regulation of UVB damage response and tumorigenesis by YTHDF2 and RNA metabolism, and may provide new opportunities for developing better strategies to prevent and treat skin cancer by targeting the YTHDF2 pathway. Given the emerging critical role of inflammation in multiple cancers, our work here in inflammation and YTHDF2 is not only significant for skin cancer, but may also be applicable to other epithelial tumor types as well.

Public Health Relevance

Our project will elucidate the crucial role of YTHDF2 and the underlying molecular pathways in inflammatory response and skin cancer pathogenesis, and may also provide new druggable targets for skin cancer prevention and therapy. Successful completion of the proposed work may reveal new druggable targets and lead to the development of improved new preventive and/or therapeutic approaches for skin cancer as well as other epithelial cancers.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
2R01ES024373-06
Application #
9983428
Study Section
Radiation Therapeutics and Biology Study Section (RTB)
Program Officer
Tyson, Frederick L
Project Start
2015-05-01
Project End
2025-04-30
Budget Start
2020-07-07
Budget End
2021-04-30
Support Year
6
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Chicago
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
005421136
City
Chicago
State
IL
Country
United States
Zip Code
60637
Robinson, Myles; Shah, Palak; Cui, Yan-Hong et al. (2018) The Role of Dynamic m6 A RNA Methylation in Photobiology. Photochem Photobiol :
Sample, Ashley; He, Yu-Ying (2018) Mechanisms and prevention of UV-induced melanoma. Photodermatol Photoimmunol Photomed 34:13-24
Shah, Palak; Zhao, Baozhong; Qiang, Lei et al. (2018) Phosphorylation of xeroderma pigmentosum group C regulates ultraviolet-induced DNA damage repair. Nucleic Acids Res 46:5050-5060
Sample, Ashley; Zhao, Baozhong; Wu, Chunli et al. (2018) The Autophagy Receptor Adaptor p62 is Up-regulated by UVA Radiation in Melanocytes and in Melanoma Cells. Photochem Photobiol 94:432-437
Zhao, Baozhong; Shah, Palak; Qiang, Lei et al. (2017) Distinct Role of Sesn2 in Response to UVB-Induced DNA Damage and UVA-Induced Oxidative Stress in Melanocytes. Photochem Photobiol 93:375-381
Yang, Seungwon; Qiang, Lei; Sample, Ashley et al. (2017) NF-?B Signaling Activation Induced by Chloroquine Requires Autophagosome, p62 Protein, and c-Jun N-terminal Kinase (JNK) Signaling and Promotes Tumor Cell Resistance. J Biol Chem 292:3379-3388
Sample, Ashley; Zhao, Baozhong; Qiang, Lei et al. (2017) Adaptor protein p62 promotes skin tumor growth and metastasis and is induced by UVA radiation. J Biol Chem 292:14786-14795
Qiang, Lei; Sample, Ashley; Shea, Christopher R et al. (2017) Autophagy gene ATG7 regulates ultraviolet radiation-induced inflammation and skin tumorigenesis. Autophagy 13:2086-2103
Sample, Ashley; He, Yu-Ying (2017) Autophagy in UV Damage Response. Photochem Photobiol 93:943-955
Qiang, Lei; Sample, Ashley; Liu, Han et al. (2017) Epidermal SIRT1 regulates inflammation, cell migration, and wound healing. Sci Rep 7:14110

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