Molecular pathogenesis of thyroid cancer

Abstract

The thyroid follicular epithelial cell (thyrocyte) responds to myriad growth-stimulating substances, including hormones, growth factors, cytokines, and other mitogens (1-15), as exemplified in Table 1. Thyrocyte responses to these factors are mediated by distinct signal transduction pathways (Figs. 1-3). Each pathway features a cell surface receptor that is linked to a specific cytoplasmic signal transduction cascade: 1. Receptor tyrosine kinase (RTK)/RAS/RAF/MEK/mitogenactivated protein kinase (MAPK) pathway (Fig. 1). 2. Thyrotropin (TSH) receptor/adenylate cyclase/protein kinase A (PKA) pathway (Fig. 2). 3. Receptor/phospholipase C (PLC)/protein kinase C (PKC) pathway (Fig. 3). © 2006 Humana Press Inc.