Establishment, characterization and comparison of seven authentic anaplastic thyroid cancer cell lines retaining clinical features of the original tumors.

BACKGROUND: Anaplastic thyroid cancer (ATC) is thought to often be transformed from pre-existing differentiated thyroid cancer. It is one of the most aggressive malignancies and has a dismal prognosis due to its resistance to multimodal therapies. Basic exploratory studies using authentic ATC cell lines that retain its clinical features are necessary. We investigated the characteristics of seven ATC cell lines newly established at our institute to confirm their possible utility for basic studies.
METHODS: Seven distinct cell lines from six patients were established. Their molecular characteristics and sensitivities to cytotoxic anti-cancer drugs were investigated and compared with each other, and with the clinical features of the original tumors.
RESULTS: All cells showed extensive chromosomal abnormality and Pax8 expression, indicating human thyroid follicular cell origin. Vascular endothelial growth factor was secreted from all cells, suggesting possible candidacy for targeted therapy. Vimentin was expressed, but E-cadherin expression was lost in all cells but OCUT-1C, which showed different features from those of OCUT-1F derived from the same tumor, suggesting a mixture of cancer cell clones with various degrees of differentiation within a single ATC tumor. Cells were likely to show sensitivity for taxanes, indicating the usefulness of taxanes as the first-line chemotherapy. OCUT-2, a cell line with both B-Raf and PI3 KCA mutation, demonstrated the importance of molecular target-oriented therapy.
CONCLUSIONS: Basic studies using authentic ATC cell lines retaining the clinical features of the original tumor are useful models for investigating the mechanism of anaplastic transformation and exploring novel therapeutic strategies.