title: On the Origin of Cells and Derivation of Thyroid Cancer: C Cell Story Revisited.
abstract: We will highlight and put into perspective new lineage tracing data from genetic studies in mice indicating that the genuine progenitors to C cells arise in the endoderm germ layer. This overturns the current concept of a neural crest origin of thyroid C cells referred to in every textbook and dedicated paper to this very day. As will become apparent, except for a single experiment, the neural crest theory has little or no support when the evolution and development of calcitonin-producing cells in the entire chordate family are considered. Instead, a unifying origin of all cells of the ultimobranchial bodies reopens questions on the histogenesis of certain thyroid pathologies previously difficult to explain. On this aspect, medullary thyroid cancer shows a stronger connection to gut neuroendocrine tumours than previously recognized. It is envisaged that novel factors implicated in C cell-derived tumour growth and progression will be discovered as the mechanisms that regulate lineage expansion of embryonic C cell precursors from pharyngeal endoderm are uncovered. We will not discuss why C cells go to the bother of burying themselves in the thyroid - this remains a mystery.
authors: Sahlgrenska Cancer Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors: Mikael
authors: M
authors: Nilsson
authors: Department of Public Health, University of Cambridge, Cambridge, UK.
authors: Dillwyn
authors: D
authors: Williams
keywords: Endoderm; Mixed medullary-follicular carcinoma; Neural crest; Neuroendocrine tumours; Thyroid C cells; Ultimobranchial body