Gastrointestinal (GI) neuroendocrine (NE) tumors such as carcinoid and islet cell tumors are the second most common cause of isolated hepatic metastases. These tumors often cause debilitating symptoms due to excessive hormonal secretion. Besides surgery, there are limited curative and palliative treatments available to patients with GI NE tumors, emphasizing the need for development of other forms of therapy. We have recently shown that over-expression of raf-1 in human GI carcinoid cells markedly suppresses NE marker expression and serotonin secretion by these tumor cells in vitro. The exact downstream factors that mediate this effect are unknown. We will present new data suggesting that activation of raf-1 in carcinoid cells results in secretion of a soluble, autocrine factor which can independently suppress hormone production in untransduced carcinoid cells. In this proposal, we will attempt to identify the soluble, autocrine factor in the conditioned media from raf-1 transduced GI carcinoid cells utilizing several strategies such as cDNA arrays and proteomics tools. The results from this proposal may have a significant impact on patients with metastatic disease from GI NE tumors. While we have shown that raf-1 activation in human carcinoid tumor cells can suppress hormone production, methods to target raf-1 induction in tumor cells would prove to be difficult. The possibility that raf-l-mediated hormone suppression could be induced by a soluble factor would provide a plausible, therapeutic delivery method.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21DK066169-01
Application #
6710986
Study Section
Metabolic Pathology Study Section (MEP)
Program Officer
May, Michael K
Project Start
2004-02-01
Project End
2006-01-31
Budget Start
2004-02-01
Budget End
2005-01-31
Support Year
1
Fiscal Year
2004
Total Cost
$145,500
Indirect Cost
Name
University of Wisconsin Madison
Department
Surgery
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Lubner, Sam J; Kunnimalaiyaan, Muthusamy; Holen, Kyle D et al. (2011) A preclinical and clinical study of lithium in low-grade neuroendocrine tumors. Oncologist 16:452-7
Greenblatt, David Yu; Ndiaye, Mary; Chen, Herbert et al. (2010) Lithium inhibits carcinoid cell growth in vitro. Am J Transl Res 2:248-53
Pinchot, Scott N; Adler, Joel T; Luo, Yinggang et al. (2009) Tautomycin suppresses growth and neuroendocrine hormone markers in carcinoid cells through activation of the Raf-1 pathway. Am J Surg 197:313-9
Adler, Joel T; Hottinger, Daniel G; Kunnimalaiyaan, Muthusamy et al. (2008) Histone deacetylase inhibitors upregulate Notch-1 and inhibit growth in pheochromocytoma cells. Surgery 144:956-61;discussion 961-2
Greenblatt, David Yu; Cayo, Max A; Adler, Joel T et al. (2008) Valproic acid activates Notch1 signaling and induces apoptosis in medullary thyroid cancer cells. Ann Surg 247:1036-40
Platta, Christopher S; Greenblatt, David Yu; Kunnimalaiyaan, Muthusamy et al. (2008) Valproic acid induces Notch1 signaling in small cell lung cancer cells. J Surg Res 148:31-7
Ning, Li; Greenblatt, David Yu; Kunnimalaiyaan, Muthusamy et al. (2008) Suberoyl bis-hydroxamic acid activates Notch-1 signaling and induces apoptosis in medullary thyroid carcinoma cells. Oncologist 13:98-104
Kappes, Ashley; Vaccaro, Abram; Kunnimalaiyaan, Muthusamy et al. (2007) Lithium ions: a novel treatment for pheochromocytomas and paragangliomas. Surgery 141:161-5;discussion 165
Kunnimalaiyaan, Muthusamy; Ndiaye, Mary; Chen, Herbert (2007) Neuroendocrine tumor cell growth inhibition by ZM336372 through alterations in multiple signaling pathways. Surgery 142:959-64;discussion 959-64
Greenblatt, David Yu; Kunnimalaiyaan, Muthusamy; Chen, Herbert (2007) Raf-1 activation in gastrointestinal carcinoid cells decreases tumor cell adhesion. Am J Surg 193:331-5;discussion 335

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