The goal of this proposal is to explore whether our newly discovered mechanism of primary tumor dormancy also governs the dormancy of metastatic cells. In our human head and neck cancer cell model, high level of urokinase receptor (uPAR) expression, prevalent in many malignant tumors, can initiate a potent MAPK-ERK activating signal by directly interacting with, and activating alpha5beta1-integrin and subsequently activating EGFR. uPAR-induced EGFR activation does not require EGFR overexpression, and is EGFR-ligand independent. uPAR-activated alpha5beta1-integrins form fibronectin (FN) fibrils that block a growth inhibitory pathway through SAPK-p38 generating a high ERK/p38 balance which is favorable for in vivo growth (tumorigenicity). Binding of urokinase plasrninogen activator (uPA) to uPAR and adhesion of cells to Fig increase the strength of the signal and tumorigenicity. Down-regulation of uPAR level, or disruption of the uPAR/integrin interaction, by inhibiting the signaling pathway, forces tumor cells into persistent dormancy. We hypothesize that, to initiate proliferation, a disseminated metastatic cancer cell needs a signal from the extracellular matrix-FN and the presence on its surface of the ERK-inducing protein assembly. Our long term goal is to map the precise role that uPAR plays in dormancy induction in this and other types of tumors, and develop reagents that will disrupt the uPAR/integrin interaction, forcing metastatic cells into persistent dormancy. We propose 3 specific aims.
Aim 1 will examine whether regulation of uPAR expression level will affect dormancy of cancer cells directly at the site of metastasis and whether uPAR contributes to organ specificity of metastases. In addition, the reciprocal sites of interaction between uPAR and cdgl-integrin will be examined to provide a basis for development of new reagents aimed at induction of cancer cell dormancy.
Specific Aim 2 will examine the mechanism of the ligand-independent, but uPAR-dependent, activation of EGFR that we have discovered. This may facilitate the future identification of specific therapeutic interventions for patients subgroups in which cancer proliferation may rely on ligand-independent EGFR activation even in the absence of EGFR overexpression. Finally, in Specific Aim 3, we will conduct a pilot study on 100 head and neck (oral) carcinomas to determine whether they express uPAR and alpha5beta1 integrin and whether these tumors can activate the proliferative MAPK-ERK pathway in absence of EGFR overexpression. ? ?

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA040758-16
Application #
6614086
Study Section
Pathology B Study Section (PTHB)
Program Officer
Ault, Grace S
Project Start
1985-08-01
Project End
2008-03-31
Budget Start
2003-04-01
Budget End
2004-03-31
Support Year
16
Fiscal Year
2003
Total Cost
$358,493
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
078861598
City
New York
State
NY
Country
United States
Zip Code
10029
Franco, Paola; Vocca, Immacolata; Carriero, Maria V et al. (2006) Activation of urokinase receptor by a novel interaction between the connecting peptide region of urokinase and alpha v beta 5 integrin. J Cell Sci 119:3424-34
Wang, Long G; Ossowski, Liliana; Ferrari, Anna C (2004) Androgen receptor level controlled by a suppressor complex lost in an androgen-independent prostate cancer cell line. Oncogene 23:5175-84
Aguirre-Ghiso, Julio A; Ossowski, Liliana; Rosenbaum, Sarah K (2004) Green fluorescent protein tagging of extracellular signal-regulated kinase and p38 pathways reveals novel dynamics of pathway activation during primary and metastatic growth. Cancer Res 64:7336-45
Aguirre Ghiso, Julio A (2002) Inhibition of FAK signaling activated by urokinase receptor induces dormancy in human carcinoma cells in vivo. Oncogene 21:2513-24
Liu, David; Aguirre Ghiso, Julio; Estrada, Yeriel et al. (2002) EGFR is a transducer of the urokinase receptor initiated signal that is required for in vivo growth of a human carcinoma. Cancer Cell 1:445-57
Aguirre-Ghiso, J A; Liu, D; Mignatti, A et al. (2001) Urokinase receptor and fibronectin regulate the ERK(MAPK) to p38(MAPK) activity ratios that determine carcinoma cell proliferation or dormancy in vivo. Mol Biol Cell 12:863-79
Wang, L G; Ossowski, L; Ferrari, A C (2001) Overexpressed androgen receptor linked to p21WAF1 silencing may be responsible for androgen independence and resistance to apoptosis of a prostate cancer cell line. Cancer Res 61:7544-51
Ossowski, L; Aguirre-Ghiso, J A (2000) Urokinase receptor and integrin partnership: coordination of signaling for cell adhesion, migration and growth. Curr Opin Cell Biol 12:613-20
Gao, M; Ossowski, L; Ferrari, A C (1999) Activation of Rb and decline in androgen receptor protein precede retinoic acid-induced apoptosis in androgen-dependent LNCaP cells and their androgen-independent derivative. J Cell Physiol 179:336-46
Aguirre Ghiso, J A; Kovalski, K; Ossowski, L (1999) Tumor dormancy induced by downregulation of urokinase receptor in human carcinoma involves integrin and MAPK signaling. J Cell Biol 147:89-104

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