The effects of Epigallocatechin-3-gallate and Dabrafenib combination on apoptosis and the genes involved in epigenetic events in anaplastic thyroid cancer cells.

Anaplastic thyroid cancer cases with poor prognosis are associated with epigenetic modifications such as abnormal DNA methylation. Epigallocathesin-3-gallate (EGCG) is a polyphenol compound of green tea that is still under investigation on its role in cancer prevention. EGCG is known as an epigenetic diet in DNA methyltransferase inhibitor. The cytotoxic effects of Dabrafenib, EGCG, and dabrafenib in combination with EGCG were assessed by using WST-8 assay; and also, Flow cytometry was utilized to identify cells undergoing apoptosis after treatments of the SW-1736 cells. We investigated the mRNA expression of genes involved in epigenetic events in SW-1736 cells by real-time qRT-PCR following the treatments. We demonstrated for the first time that the Dabrafenib-EGCG combination reduced cell viability significantly depending on concentration and induced apoptosis by 8.49-fold through investigating the additive effect together on SW-1736 cells. The IC50 doses of Dabrafenib and EGCG for 48 h were determined as 6.7 µM and 22.5 µM, respectively. The results of qRT-PCR demonstrated that the Dabrafenib-EGCG combination significantly caused the down-regulation of genes involved in epigenetic regulation. We suggest that the combination of Dabrafenib and EGCG following in vivo phase studies will contribute as an alternative treatment option for the treatment of ATC.

Effect of valproic acid on miRNAs affecting histone deacetylase in a model of anaplastic thyroid cancer.

BACKGROUND: Thyroid cancer is the most common malignant tumor of the endocrine system seen in the thyroid gland. More than 90% of thyroid cancers comprise papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC). Although anaplastic thyroid carcinoma (ATC) accounts for less than 2% of thyroid cancer. But patients' lifespan after diagnosis is about 6 months. Surgical interventions, radioactive iodine use, and chemotherapy are not sufficient in the treatment of ATC, so alternative therapies are needed. METHODS AND RESULTS: The WST-1 assay test was performed to evaluate the anti-proliferative effects of Valproic acid (VPA). Also, the effect of VPA on miRNAs affecting histone deacetylase was determined by Quantitative RT-PCR. In the SW1736 cell line, IC50 dose for VPA was found 1.6 mg/ml. In our study, the level of oncogenic genes expression in cells treated with VPA, including miR-184, miR-222-5p, miR-124-3p, and miR-328-3p, decreased. Also, the expression of tumor inhibitory genes including miR-323-5p, miR-182-5p, miR-138-5p, miR-217, miR-15a-5p, miR-29b-3p, miR-324-5p and miR-101-5p increased significantly. CONCLUSIONS: VPA can ad-just countless gene expression patterns, including microRNAs (miRNAs), by targeting histone deacetylase (HDAC). However, further studies are required for more accurate results.