Anaplastic and differentiated thyroid carcinoma express different profiles of angiogenic stimuli and inhibitors

Karen Penko1, Russell Moores2, Aneeta Patel2, R. Michael Tuttle3, Motoyasu Saji4, Matthew Ringel4, and Gary Francis2

1Pediatrics, SAUHSEC, San Antonio, TX; 2Pediatrics, USUHS, Bethesda, MD; 3Endocrinology, Memorial Sloan Kettering Cancer Center, New York, NY; 4Endocrinology, Washington Hospital Center, Washington, DC.

Background: Thyroid carcinoma are the most common malignant endocrine tumors, and anaplastic thyroid carcinoma (ATC) are the most aggressive. Recent studies have shown that vascular endothelial growth factor (VEGF)-induced angiogenesis is important for the growth of ATC, suggesting drugs that inhibit angiogenesis might be effective treatment. However, all angiogenic stimuli produced by ATC have yet to be described, and lack of this knowledge precludes optimal development of anti-angiogenesis treatments. Objective: To identify and quantify gene expression for angiogenic stimuli and inhibitors from ATC and differentiated thyroid carcinoma. Design/Methods: ATC and differentiated thyroid carcinoma cells (NPA) were grown in culture. On the day of study, media were replaced with serum free media to remove any growth factors (24 hr). Cells were digested (RNA-WIZ) and total RNA was extracted, precipitated and washed. Duplicate RNA extracts (6 :g) were hybridized to the Human Cancer Angiogenesis II Microarray (Superarray, Gaithersburg, MD). Hybridization was detected by enhanced chemiluminescence, and quantified (Kodak Imaging Station) relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Results: Intense expression (similar to the intensity of GAPDH) of angiopoeitin-1 (Ang-1), plasminogen activator inhibitor-type 1, vascular endothelial growth factor (VEGF) and VEGF-D (also known as c-fos induced growth factor) were detected in ATC, but not NPA cells. ATC also expressed less intense amounts of transforming growth factor-" (TGF-") and TGF-$. In contrast, pigment epithelium derived factor was detected only in NPA cells, and the intensity of its expression was similar to that of GAPDH. Conclusions: ATC intensely express several angiogenic stimuli including Ang-1, VEGF, and VEGF-D along with lesser amounts of TGF-" and TGF-$. This combination is of potential importance to the aggressive nature of ATC, because VEGF and Ang-1 act synergistically to induce proliferation of endothelial cells (VEGF) and stabilize new blood vessels (Ang-1). Of additional interest, is the expression of pigment epithelium derived factor by the more differentiated and less aggressive NPA cells. Pigment epithelium derived factor inhibits angiogenesis and its expression might be important in the more indolent behavior of differentiated thyroid carcinoma (NPA).

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Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Paris, France; February 9 - 12, 2002; in the section on Angiogenesis.

This presentation was a winner in our poster contest and was recognized with the Symposium Presidents' Award for Scientific Excellence.