Establishment of a new human thyroid medullary carcinoma cell line. Morphological studies

A new human medullary carcinoma cell line has been established from a thyroid tumor removed from a 76-year-old female patient. The cultured cells grew in suspension, formed round islands and did not attach to the plastic dish. The doubling time of 48 h is the shortest recorded for C-cell lines. Ultrastructural studies disclosed that the cells had a few short profiles of rough endoplasmic reticulum, numerous ribosomes and polyribosomes, a poorly developed Golgi apparatus and small secretory granules (75 nm in mean diameter). Immunohistochemical staining for somatostatin was positive. These results show that, compared with previously established C-cell lines, this cell line has a rapid growth rate, is morphologically less differentiated, but retains a hormone production potential.