ANTITUMOR EFFECTS OF SULPHORAPHANE ON THYROID CARCINOMA CELL LINES

Abstract

Thyroid cancer is the most frequent endocrine malignancy with a global increasing incidence. Many evidences show that sulphoraphane (SF), a natural isothiocyante found in cruciferous vegetables has a wide range of chemopreventive as well as apoptosis inducing properties. The ability of SF in inducing apoptosis and cell cycle arrest is associated with the regulation of many proteins including Bcl-2 family proteins, caspases, p21, and cyclin dependent kinases. In the present work, we investigated in vitro the activity of SF in three human thyroid cancer cell lines. For this purpose we studied SW1736 (ATC), BC-PAP (PTC) and TT (MTC) cell line by MTT assay, after addition of SF ranging from 0 to 20M. Cell lines were treated with SF at different concentration (1M, 5M, 10M, 20M) for 72 hours and after treatment we observed a SF- induced toxicity in all thyroid cancer cell lines, whereas SF had not significant effects on nonmalignant cells. In order to demonstrate the role of SF in the apoptotic pathway, we analyzed its effect on Bcl-2 and BAX protein expression by western blot. The increase of SF concentration induce an upregulation of BAX followed by down-regulation of Bcl-2, confirming its pro-apoptotic role in all three cell lines. So, our preliminary data, suggest its possible use in prevention trial in high-risk areas and as enhancer in anti-neoplastic therapy of thyroid cancer.