Clonally related but phenotypically divergent human cancer cell lines derived from a single follicular thyroid cancer recurrence (TT2609)

Starting from different regional samples taken from a heterogeneous follicu lar thyroid cancer recurrence in a male patient, a series of cell cultures was initiated. Three stable cancer cell lines were successfully established (TT2609-A02, TT2609-B02, and TT2609-C02) and kept in continuous culture fo r more than 3 years. The lines are each characterized by a unique set of bi ological parameters such as morphology, ploidy state, cell proliferation ra te, ultrastructure, thyroid marker expression, p53 expression, karyogram, a gar clonogenic capacity and tumorigenicity as xenografts in nude mice. Thes e characterization studies point to a marked heterogeneity at the level of the clinical tumor recurrence. Karyotype analysis of the cell lines showed a pattern of aberrations indicating that the lines are clonally related and that the A02 and C02 lines are subsequently derived from the more "origina l" tumor cell type B02 after a tetraploidization event. It is concluded tha t the obtained cell lines represent an in vitro/in vivo model for human fol licular thyroid cancer. The availability of a series of cell lines for huma n follicular thyroid cancer, mimicking the biological heterogeneity observe d in patient tumors, enables both detailed fundamental investigation of thy roid cancer cell biology and the experimental exploration of new treatment approaches.