RET Proto-oncogene in the Pathogenesis of Thyroid Cancer,MEN 2 Syndromes and Hirschsprung’sDisease

Overview

The defects in the RET proto-oncogene are the cause of several clinically distinct disorders. The activating(gain-of-function) mutations induce both the familial forms of medullary thyroid carcinoma (MTC), MEN 2syndromes associated with pheochromocytoma, hyperparathyroidism (MEN 2A) or marfanoid habitus and otherlesions (MEN 2B), and sporadic forms of MTC, where the mutations are present only in the tumor tissue. Thedetection of mutations has considerable diagnostic importance especially for persons at risk when early therapeuticalintervention could prevent the onset of the disease. The frequent case of papillary thyroid cancer is thetranslocation or inversion within theRETproto-oncogene and its fusion with other genes rising in chimeric proteinswhich activate the RET signalling. Conversely the inactivating (loss-of-function) mutations, deletions or insertionsare the most frequent cause of Hirschsprung’s disease marked by lack of innervation of variable lengths of thehind gut. The intensive study of the physiological role of RET protein - the receptor tyrosine kinase - in normalcell proliferation, differentiation and survival promises possible therapeutic application of this knowledge, esp. inthe treatment of neurodegenerative disorders.

Key words:
RET proto-oncogene, medullary thyroid carcinoma, papillary carcinoma, MEN 2A, MEN 2B,Hirschsprung’s disease, genetics