Changes in the concentration of intracellular free Ca2+ ([Ca2+]i) caused by the influx of external Ca2+ or by the release of Ca2+ from stores in the endoplasmic reticulum play an important role in mediating the effects of growth factors and oncogenes on cell proliferation. A major function of proto-oncogenes is to code for components of intracellular signal transduction pathways. The inappropriate expression of an oncogene product or its modification through mutation can lead to constitutive activation of an intracellular signal transduction pathway that is thought to be a cause of unrestrained or transformed cell growth. Several oncogenes act through pathways involving changes in [Ca2+]i. [Ca2+]i signalling, thus, represents a novel and attractive target site for developing drugs to selectively block abnormal oncogene expression in transformed cells and offers the promise of the selective control of tumor cell growth. The goal of the project is to isolate and study novel chemical structures that inhibit growth factor and oncogene related Ca2+ signalling in tumor cells. The primary biochemical target used to screen compounds will be the uptake and second messenger mediated release of 45Ca2+ by the endoplasmic reticulum of permeabilized tumor cells. The compounds will be derived from plant extracts by bioassay directed fractionation, and by the chemical modification of known active agents in collaboration with Project 1. Secondary studies will investigate the ability of selected agents to affect [Ca2+]i signalling in intact cells, particularly the integration of [Ca2+]i signalling with the signal transduction pathways studied by Projects 3 and 4. Active agents will be tested for in vitro growth inhibitory activity by Project 5 and in vivo antitumor activity in animal models by Project 6. The ultimate objective of the studies is to develop new classes of antitumor agents for clinical trial in patients.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01CA052995-04
Application #
3795922
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Arizona
Department
Type
DUNS #
City
Tucson
State
AZ
Country
United States
Zip Code
85721
Gwak, Ho-Shin; Shingu, Takashi; Chumbalkar, Vaibhav et al. (2011) Combined action of the dinuclear platinum compound BBR3610 with the PI3-K inhibitor PX-866 in glioblastoma. Int J Cancer 128:787-96
Ihle, N T; Powis, G; Kopetz, S (2011) PI-3-Kinase inhibitors in colorectal cancer. Curr Cancer Drug Targets 11:190-8
Liu, Enbo; Knutzen, Christine A; Krauss, Sybille et al. (2011) Control of mTORC1 signaling by the Opitz syndrome protein MID1. Proc Natl Acad Sci U S A 108:8680-5
Leone, Marilisa; Barile, Elisa; Vazquez, Jesus et al. (2010) NMR-based design and evaluation of novel bidentate inhibitors of the protein tyrosine phosphatase YopH. Chem Biol Drug Des 76:10-6
Ihle, Nathan T; Powis, Garth (2010) The biological effects of isoform-specific PI3-kinase inhibition. Curr Opin Drug Discov Devel 13:41-9
Koul, Dimpy; Shen, Ruijun; Kim, Yong-Wan et al. (2010) Cellular and in vivo activity of a novel PI3K inhibitor, PX-866, against human glioblastoma. Neuro Oncol 12:559-69
Ihle, Nathan T; Powis, Garth (2010) Inhibitors of phosphatidylinositol-3-kinase in cancer therapy. Mol Aspects Med 31:135-44
Gaitonde, Supriya; De, Surya K; Tcherpakov, Marianna et al. (2009) BI-69A11-mediated inhibition of AKT leads to effective regression of xenograft melanoma. Pigment Cell Melanoma Res 22:187-95
Ihle, Nathan T; Lemos, Robert; Schwartz, David et al. (2009) Peroxisome proliferator-activated receptor gamma agonist pioglitazone prevents the hyperglycemia caused by phosphatidylinositol 3-kinase pathway inhibition by PX-866 without affecting antitumor activity. Mol Cancer Ther 8:94-100
Ihle, Nathan T; Lemos Jr, Robert; Wipf, Peter et al. (2009) Mutations in the phosphatidylinositol-3-kinase pathway predict for antitumor activity of the inhibitor PX-866 whereas oncogenic Ras is a dominant predictor for resistance. Cancer Res 69:143-50

Showing the most recent 10 out of 14 publications