Intracellular signalling mechanisms in thyroid cancer

BackgroundThyroid cancer is the most common malignancy of the endocrine system, the papillary variant accounts for 80–90% of all diagnosed cases. In the development of papillary thyroid cancer, BRAF and RAS genes are mainly affected, resulting in a modification of the system of intracellular signalling proteins known as “protein kinase mitogen-activated” (MAPK) which consist of “modules” of internal signalling proteins (Receptor/Ras/Raf/MEK/ERK) from the cell membrane to the nucleus. In thyroid cancer, these signanling proteins regulate diverse cellular processes such as differentiation, growth, development and apoptosis. MAPK play an important role in the pathogenesis of thyroid cancer as they are used as molecular biomarkers for diagnostic, prognostic and as possible therapeutic molecular targets. Mutations in BRAF gene have been correlated with poor response to treatment with traditional chemotherapy and as an indicator of poor prognosis.ObjectiveTo review the molecular mechanisms involved in intracellular signalling of BRAF and RAS genes in thyroid cancer.ConclusionsMolecular therapy research is in progress for this type of cancer as new molecules have been developed in order to inhibit any of the components of the signalling pathway (RET/PTC)/Ras/Raf/MEK/ERK; with special emphasis on the (RET/PTC)/Ras/Raf section, which is a major effector of ERK pathway