Antineoplastic activity of 1,25(OH)2D3 and its analogue 22-oxacalcitriol against human anaplastic thyroid carcinoma cell lines in vitro.

Anaplastic carcinoma of thyroid is uncommon and is associated with a poor prognosis. an effective treatment of this carcinoma has not been found. We have examined the inhibition of promotion by 1, 25(OH)2D3 and its analogue without hypercalcemia, 22-oxacalcitriol (OCT) in the thyroid anaplastic carcinoma cell line. TTA-1, thyroid anaplastic carcinoma cell line, and TAC-1, thyroid anaplastic carcinoma cells. TPC-1,2,3,4, which are all papillary carcinoma of thyroid were used as control. Tumor growth was measured by MTT assay. 1,25(OH)2D3 additive cell growth was observed in diphasic pattern in 3/4 papillary carcinoma cell lines. OCT was more effective, showing dose-dependent inhibition of cell growth in anaplastic carcinoma cell lines, than that in papillary carcinoma cells. Conclusively, OCT might be useful for the inhibition of growth in anaplastic thyroid cancer.