Poster Sessions

C-56

Ritika Dogra

R. S Dogra, B. H. Joshi, R. Lloyd, J Kasperbauer, R. K. Puri

Identification and characterization of Interleukin-13 receptors (IL-13R) in Human Papillary thyroid cancers

Papillary thyroid carcinoma constitutes 80%-90% of all thyroid carcinoma cases that commonly occurs in young population. Most common therapeutic approaches available are surgery and radiotherapy with limited benefits. Previously, we have demonstrated that a variety of human cancers express abundant levels of IL-13R, which sensitizes tumors to receptor-directed therapeutic agents such as a chimeric fusion protein consisting of IL-13 and a truncated Pseudomonas exotoxin (IL-13PE). As IL-13R expression in thyroid carcinoma may serve as a novel target for IL-13PE based anti-cancer therapy, we have determined its expression in human papillary thyroid carcinoma specimens by triple immunohistochemistry for IL-13Rα2, IL-13Rα1 and IL-4Rα chains. 38 thyroid carcinoma specimens obtained from Mayo Clinic were stained, of which 25 (66%) showed strong expression for IL13Ralpha2. In addition, 90% metastatic specimens were positive for IL-13Rα2 chain compared to 38% samples expressing in primary tumor specimens. Our ongoing study will focus on in situ hybridization analysis for IL-13R transcripts in these specimens and normal thyroid samples. The role of IL-13Ralpha2 in thyroid cancer cell lines and safety and efficacy of IL-13PE for thyroid cancer therapy in animal models is currently being studied.