Influences of polyaromatic hydrocarbons and heavy metals on a thyroid carcinoma cell line

We investigated the influences (cell toxicity, endocrine disrupting action, etc.) of polyaromatic hydrocarbons (PAHs) and heavy metals on the human thyroid gland by using a cultured thyroid cancer cell (8505C). Among the six PAHs tested (anthracene, benzo[a]anthracene, benzo[a]pyrene, benzo[k]fluoranthene, chrysene and pyrene), anthracene did not show any effect, but cell proliferation was enhanced by benzo[a]anthracene, benzo[a]pyrene and benzo[k]fluoranthene. Benzo[a]pyrene had an especially marked effect. On the other hand, cell toxicity was exhibited in four (cadmium, copper, nickel and zinc) of the twelve metals tested (aluminum, cadmium, calcium, copper, lead, magnesium, manganese, nickel, tin, zinc, selenate and selenite), and in particular, the influence of cadmium was remarkable. It was found that the toxicity of cadmium was decreased by the addition of high concentrations of either calcium or selenite.