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The People of Tulane Cancer Center Research


Patrice DelafontainePatrice Delafontaine, M.D.
Professor in the Department of Medicine
Chief, Section of Cardiology
Director, Tulane University Heart & Vascular Institute
Tulane Cancer Center Contributing Member

Contact Information
Email: pdelafon@tulane.edu
Phone: 504-988-2025
Address: 1430 Tulane Ave., Box SL-48, New Orleans, LA 70112-2699


Biographical Narrative

Our primary research interests center on the biology of the IGF-1 system and its role in pathophysiological conditions. Our group was the first to clone the rat IGF-1 receptor and we have studied its molecular regulation and its role in cell proliferation, survival and differentiation. Several years ago we reported that the IGF-1 receptor 5′ untranslated region contains an internal ribosomal entry site (IRES), which is important for regulation of cellular receptor density. Recently (Higashi, et al J Biol Chem. 2010 Sep 15 [Epub ahead of print]), we reported that the antidiabetic compounds, thiazolidinediones (TZDs), upregulate IGF-1 receptor expression via a PPAR? independent mechanism, a finding that could be important in explaining the clinical effects of these compounds. Our studies focusing on molecular regulation of IGF-1 expression are directly relevant to mechanisms of cell cycle control and to the pathophysiology of cancer, as well as of proliferative vascular disorders. We have also studied involvement of the ubiquitin-proteasome system and of IGF-1 in muscle cachexia, a common complication of cancer and of advanced heart failure.

Selected Publications
Higashi Y, Holder K, Delafontaine P. Thiazolidinediones upregulate insulin-like growth factor-1 receptor via a peroxisome proliferator-activated receptor {gamma}-independent pathway. J Biol Chem. 2010 Sep 15. [Epub ahead of print] PMID: 20843793

Giraud S, Greco A, Brink M, Diaz JJ, Delafontaine p. Translation Initiation of the Insulin-like Growth Factor I Receptor mRNA is Mediated by an Internal Ribosome Entry Site. J Biol Chem. 2001;276(8):5668-75. E-pub 2000 Nov 3.

Scheidegger KJ, Cenni B, Picard D, Delafontaine p. Estradiol decreases IGF-1 and IGF-1 receptor expression in rat aortic smooth muscle cells: mechanisms for its atheroprotective effects? J Biol Chem 2000;275(49):38921-8.

Scheidegger KJ, James RW, Delafontaine p. Differential effects of low density lipoproteins on IGF-1 and IGF-1R expression in vascular smooth muscle cells. J Biol Chem. 2000;275(35):26864-9.

Scheidegger KJ, Du J, Delafontaine p. Distinct and Common Pathways in the Regulation of Insulin-Like Growth Factor-1 Receptor Gene Expression by Angiotensin II and basic Fibroblast Growth Factor. J Biol Chem 1999;274(6):3522-3530.

Ali MS, Schieffer B, Delafontaine P, Bernstein KE, Ling BN, Marrero MB. Angiotensin II stimulates tyrosine phosphorylation and activation of insulin receptor substrate 1 and protein-tyrosine phosphatase 1D in vascular smooth muscle cells. J Biol Chem 1997;272(19):12373-9.

Rao GN, Delafontaine P, Runge MS. Thrombin Stimulates Phosphorylation of Insulin-like Growth Factor I Receptor, Insulin Receptor Substrate-1, and Phospholipase C-g1 in Rat Aortic Smooth Muscle Cells. J Biol Chem 1995;270(46):27871-27875.

Delafontaine P, Meng XP, Ku L, Du J. Regulation of Vascular Smooth Muscle Cell Insulin-Like Growth Factor I Receptors by Phosphorothioate Oligonucleotides. Effects on Cell Growth and Evidence that Sense Targeting at the ATG site Increases Receptor Expression. J Biol Chem 1995;270(24):14383-14388.

Delafontaine P, Lou H. Angiotensin II Regulates Insulin-Like Growth Factor I Gene Expression in Vascular Smooth Muscle Cells. J Biol Chem 1993;268(22):16866-16870.

Griendling KK, Delafontaine P, Rittenhouse SE, Gimbrone MA Jr, Alexander RW. Correlation of Receptor Sequestration with Sustained Diacylglycerol Accumulation in Angiotensin II-Stimulated Cultured Vascular Smooth Muscle Cells. J Biol Chem 1987 Oct; 262(30):14555-14562.

 

1430 Tulane Ave, New Orleans, LA 70112 504-988-5263 medsch@tulane.edu