Epithelial cancers, or carcinomas, account for greater than 90% of all human cancers. In particular, cancers of the stratified epithelia, such as the skin and the tissues of the head and neck, are common, and can display poor prognosis in advanced stages. Perturbations in cell-cell adhesion play an important part in late stages of cancer, where they can facilitate invasion and metastasis. Although loss of adherens junction function is established to be important for tumor progression and metastasis, the role of the related adhesion junction, the desmosome, in cancer is poorly understood. Specifically, while studies have suggested that desmosome components are downregulated during tumor progression in humans, genetic studies to examine the role of desmosome inactivation in cancer using knockout mice have not been performed. We recently found that the Perp tetraspan membrane protein, which we originally identified as a target of the p53 tumor suppressor, is also an effector of the p63 stratified epithelial development program, where it plays an essential role in desmosome function and epithelial integrity. As is common with desmosome component knockout mice, Perp null mice display lethality, and thus the Perp conditional knockout mice we generated will provide a unique means to assess the contribution of desmosome loss in cancer, through ablation of Perp in a spatially and temporally regulated manner. Thus, to understand the role of desmosomes in cancer, we propose to use the Perp-deficient mice we have generated to examine the consequence of Perp loss in multiple tumor models, both in vitro and in vivo. In addition, although Perp is essential for desmosomal adhesion, the means by which it promotes desmosome function is unknown. Therefore, to define Perp's mechanism of action, we will generate a panel of Perp mutants to map important functional domains involved in adhesion and suppressing tumorigenesis. In conjunction with experiments we will perform to identify Perp-interacting desmosomal proteins and to characterize their role in tumorigenesis. These studies will help reveal whether Perp function in suppressing cancer relates to its ability to promote adhesion or another function. Together, these approaches will help elucidate how Perp, and desmosomes, contribute to epithelial integrity and cancer, and will provide insight into p63 function in cancer. An understanding of the factors affecting cancer progression ultimately will be important for better diagnosis, prognosis and therapy. ? ? ? ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA093665-06A1
Application #
7262168
Study Section
Tumor Microenvironment Study Section (TME)
Program Officer
Ault, Grace S
Project Start
2002-01-01
Project End
2012-01-31
Budget Start
2007-04-19
Budget End
2008-01-31
Support Year
6
Fiscal Year
2007
Total Cost
$283,177
Indirect Cost
Name
Stanford University
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Dusek, Rachel L; Bascom, Jamie L; Vogel, Hannes et al. (2012) Deficiency of the p53/p63 target Perp alters mammary gland homeostasis and promotes cancer. Breast Cancer Res 14:R65
Baron, Sylvain; Hoang, Anabel; Vogel, Hannes et al. (2012) Unimpaired skin carcinogenesis in Desmoglein 3 knockout mice. PLoS One 7:e50024
Dusek, Rachel L; Attardi, Laura D (2011) Desmosomes: new perpetrators in tumour suppression. Nat Rev Cancer 11:317-23
Beaudry, Veronica G; Ihrie, Rebecca A; Jacobs, Suzanne B R et al. (2010) Loss of the desmosomal component perp impairs wound healing in vivo. Dermatol Res Pract 2010:759731
Beaudry, Veronica G; Jiang, Dadi; Dusek, Rachel L et al. (2010) Loss of the p53/p63 regulated desmosomal protein Perp promotes tumorigenesis. PLoS Genet 6:e1001168
Beaudry, Veronica G; Pathak, Navneeta; Koster, Maranke I et al. (2009) Differential PERP regulation by TP63 mutants provides insight into AEC pathogenesis. Am J Med Genet A 149A:1952-7
Ihrie, R A; Bronson, R T; Attardi, L D (2006) Adult mice lacking the p53/p63 target gene Perp are not predisposed to spontaneous tumorigenesis but display features of ectodermal dysplasia syndromes. Cell Death Differ 13:1614-8
Marques, Michelle R; Ihrie, Rebecca A; Horner, Jennifer S et al. (2006) The requirement for perp in postnatal viability and epithelial integrity reflects an intrinsic role in stratified epithelia. J Invest Dermatol 126:69-73
Ihrie, Rebecca A; Attardi, Laura D (2005) A new Perp in the lineup: linking p63 and desmosomal adhesion. Cell Cycle 4:873-6
Ihrie, Rebecca A; Marques, Michelle R; Nguyen, Bichchau T et al. (2005) Perp is a p63-regulated gene essential for epithelial integrity. Cell 120:843-56

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