Follicular thyroid cancer cells: a model of metastatic tumor in vitro (review).

We used a thyroid metastatic tumor model to analyze some of the mechanisms of invasion and metastasis in culture. Chronic TSH stimulation (thyroid stimulating hormone) was associated with enhanced tumor proliferation and aggressiveness. We present a unique metastatic tumor model including three follicular thyroid cancer cell lines using a human primary tumor and two metastases of the same patient. They contain thyroglobulin, have intact thyroid functions and response to TSH. Investigating growth factor sensitivity we found that the amplitude of stimulation or inhibition of invasion was significantly smaller in both metastatic cell lines. Unstimulated cells of the lung metastasis had the highest basal invasive potential, but were only minimally affected by the stimulation of growth factors. In contrast, the parental cell line had the lowest basal invasiveness, but was considerably stimulated by growth factors.