In epidermis, the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase (Erk MAPK) pathway is activated in a majority of spontaneous human squamous cell carcinomas (SCCs) and can combine with G1 escape to directly transform intact human tissue into lethal SCC. Characterizing Erk MAPK pathway function in normal and neoplastic epidermis has been the longstanding focus of AR49737 and remains so in this competing renewal. Efforts in the prior funding cycle achieved the first disruption of the pathway in mammalian tissue, an advance that underscored its importance in homeostasis and oncogenesis. The current proposal focuses on promising pathway regulators and effectors, namely MAPK-interacting proteins (MAPK-IPs) and newly discovered MAPK-controlled long noncoding RNAs (ncRNAs). First, we will extend our recent findings indicating that loss of the IQGAP1 MAPK-IP selectively blocks epidermal neoplasia without disrupting homeostasis in normal epidermal tissue. We will define the functional domains of IQGAP1 required for Erk MAPK-driven epidermal neoplasia. These efforts will help identify potentially important neoplasia-selective interactions of IQGAP1. In parallel, we will also assess the therapeutic potential of IQGAP1 in SCC by depleting IQGAP1 in early neoplastic progression versus in established neoplasia. These studies are designed to elucidate the role of IQGAP1 in Erk MAPK-driven epidermal neoplasia. Second, we will characterize Erk MAPK targets identified during the prior cycle that represent a putative new class of MAPK effectors, namely long ncRNAs within the epidermal differentiation complex (EDC) on chromosome 1q21. We have termed these new ncRNAs, NEDCRs (noncoding EDC RNAs). To identify the functionally important MAPK targets within this group, we will define NEDCR effects on epidermal growth and differentiation. In parallel, we will focus on NEDCR1 as a prototype for the next level of studies because it dominantly controls epidermal differentiation. We will define the role of NEDCR1 in Erk MAPK-driven epidermal neoplasia. These studies are designed to define the basis for Erk MAPK pathway control of epidermal homeostasis and neoplasia by new ncRNA targets of Erk MAPK action. At the end of the proposed funding period, we hope to have defined the mechanistic basis for the selective requirement for the IQGAP1 MAPK-IP in epidermal neoplasia but not homeostasis and to have characterized the role of a newly discovered class of Erk MAPK effectors, namely long ncRNAs, in the regulation of epidermal homeostasis and cancer.

Public Health Relevance

The epidermis is the site of more cancers than any other body tissue and serves as a paradigm for cancers of other epithelial tissues. The Erk MAPK pathway controls both normal epidermal renewal and carcinogenesis. We are characterizing the role of proteins that interact with the Erk MAPK pathway and of novel noncoding RNA targets that may mediate its broad gene regulatory effects in normal and cancerous epidermis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR049737-07
Application #
7867984
Study Section
Molecular Oncogenesis Study Section (MONC)
Program Officer
Baker, Carl
Project Start
2003-04-01
Project End
2014-04-30
Budget Start
2010-05-01
Budget End
2011-04-30
Support Year
7
Fiscal Year
2010
Total Cost
$353,765
Indirect Cost
Name
Stanford University
Department
Dermatology
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Ransohoff, Julia D; Wei, Yuning; Khavari, Paul A (2018) The functions and unique features of long intergenic non-coding RNA. Nat Rev Mol Cell Biol 19:143-157
Ramanathan, Muthukumar; Majzoub, Karim; Rao, Deepti S et al. (2018) RNA-protein interaction detection in living cells. Nat Methods 15:207-212
Siprashvili, Zurab; Webster, Dan E; Johnston, Danielle et al. (2016) The noncoding RNAs SNORD50A and SNORD50B bind K-Ras and are recurrently deleted in human cancer. Nat Genet 48:53-8
Zarnegar, Brian J; Flynn, Ryan A; Shen, Ying et al. (2016) irCLIP platform for efficient characterization of protein-RNA interactions. Nat Methods 13:489-92
Bao, Xiaomin; Rubin, Adam J; Qu, Kun et al. (2015) A novel ATAC-seq approach reveals lineage-specific reinforcement of the open chromatin landscape via cooperation between BAF and p63. Genome Biol 16:284
Flynn, Ryan A; Martin, Lance; Spitale, Robert C et al. (2015) Dissecting noncoding and pathogen RNA-protein interactomes. RNA 21:135-43
Noderer, William L; Flockhart, Ross J; Bhaduri, Aparna et al. (2014) Quantitative analysis of mammalian translation initiation sites by FACS-seq. Mol Syst Biol 10:748
Jameson, Katherine L; Mazur, Pawel K; Zehnder, Ashley M et al. (2013) IQGAP1 scaffold-kinase interaction blockade selectively targets RAS-MAP kinase-driven tumors. Nat Med 19:626-630
Kretz, Markus; Siprashvili, Zurab; Chu, Ci et al. (2013) Control of somatic tissue differentiation by the long non-coding RNA TINCR. Nature 493:231-5
Sen, George L; Boxer, Lisa D; Webster, Dan E et al. (2012) ZNF750 is a p63 target gene that induces KLF4 to drive terminal epidermal differentiation. Dev Cell 22:669-77

Showing the most recent 10 out of 26 publications