Effect of metformin alone and in combination with etoposide and epirubicin on proliferation, apoptosis, necrosis, and migration of B-CPAP and SW cells as thyroid cancer cell lines

BACKGROUND AND PURPOSE: There has not been a comprehensive study on the simultaneous effects of metformin, etoposide, and epirubicin on thyroid cancer cells. Hence, the current research proposed the in vitro study on the effect of metformin alone and in combination with etoposide and epirubicin on the rate of proliferation, apoptosis, necrosis, and migration against B-CPAP and SW-1736 cells as thyroid cancer cell lines. EXPERIMENTAL APPROACH: MTT-based proliferation assay, combination index method, flow cytometry, and scratch wound healing assays were used to evaluate the simultaneous effects of the three approved drugs against thyroid cancer cells. FINDINGS/RESULTS: This study showed that the toxic concentration of metformin on normal Hu02 cells was more than 10 folds higher than B-CPAP and SW cancerous cells. Metformin in combination with epirubicin and etoposide could increase percentages of B-CPAP and SW cells in early and late apoptosis and necrosis phases in comparison with their single concentrations, significantly. Metformin in combination with epirubicin and etoposide could arrest the S phase in B-CPAP and SW cells, significantly. Metformin in combination with epirubicin and etoposide could reduce ~100% migration rate, whereas single concentrations of epirubicin and etoposide could reduce ~50% migration rate. CONCLUSION AND IMPLICATION: Combined treatment of metformin with anticancer drugs epirubicin and etoposide can increase the mortality in thyroid cancer cell lines and reduce the toxicity of these drugs on the normal cell line, which could be the starting point for proposing a new combination strategy in the therapy of thyroid cancer to induce more potency and reduce acute toxicity.