Diallyl sulfide induces growth inhibition and apoptosis of anaplastic thyroid cancer cells by mitochondrial signaling pathway

Anaplastic thyroid carcinoma (ATC) is one of the most lethal solid tumors arising thyroid gland with dismal prognosis. One of the constituents of garlic, diallyl sulfide (DAS) was shown to inhibit chemically induced carcinogenesis in many animal models. This study examined whether DAS could induce growth inhibition and apoptosis in ATC cells. In MTT assay, DAS treatment inhibited the proliferation of ARO cells in a dose-dependent manner. Flow cytometric analysis showed that DAS treatment increased the accumulation of sub-G1 DNA and concomitant accumulation of cells in the G2/M phase in a dose-dependent manner. In addition, DAS-induced apoptosis was associated with a decrease in the level of Bcl-2 expression and an increase in the level of Bax expression, and cytochrome c was remarkably released from mitochondrial into the cytosol by DAS. Furthermore, caspase-9 and caspase-3 were activated by DAS, and DAS cleaved PARP. Taken together, DAS decreased cell proliferation and induced apoptosis via mitochondrial signaling pathway in ATC cells.