Perfluorooctane sulfonate (PFOS) increases metastatic potential of thyroid cancer cells in correlation with activation of multiple invasion-related signaling proteins

Perfluorooctane sulfonate (PFOS) is a man-made chemical widely used in many products and acts as an endocrine-disrupting chemical (EDC). PFOS has spread to the environment through industrial manufacturing processes and disposal of PFOS-containing products. There is growing evidence that environmental pollutants may have promoting effects on cancer cell aggressiveness, rapid growth, and metastasis. Thyroid cancer is an endocrine-related cancer that can respond to EDCs. This study aimed to explore the effect of PFOS on the growth and metastatic potential (invasion capability) of FTC-133 human thyroid cancer cells. PFOS exposure for 72 h (1 pM to 10 µM) did not stimulate growth of FTC-133 cells. However, PFOS exposure at low concentration (1 nM) enhanced invasion capability of the cells, with no correlation to the expression level of estrogen receptors. FTC-133 cells exposed to 1 nM PFOS displayed increasing phosphorylation of multiple invasion-related signaling proteins, including Akt, ERK, and EphA2. Our study revealed that PFOS at low concentration may influence thyroid cancer progression by increasing the metastatic potential of cancer cells.