Synergistic anticancer activity of sorafenib, paclitaxel, and radiation therapy on anaplastic thyroid cancer in vitro and in vivo.

BACKGROUND This study aimed to investigate the antitumor activity of paclitaxel with radiation and sorafenib in anaplastic thyroid cancer (ATC) cells in vitro and in vivo. METHODS The 8505C ATC cell line was exposed to radiation, sorafenib, and paclitaxel each or in combination. The effects of combined treatment on the cell cycle and intracellular signaling pathways were assessed using flow cytometry and western blot analysis. An ATC cell line xenograft model was used to examine antitumor activity in vivo. RESULTS Radiation, paclitaxel plus sorafenib synergistically decreased cell viability in ATC cells and significantly increased apoptotic cell death. The combination of paclitaxel, sorafenib with radiation reduced the antiapoptotic factor in ATC. This combination therapy significantly reduced the tumor volume and increased survival in the ATC xenograft model. CONCLUSIONS These results suggest that the combination of radiation and paclitaxel plus sorafenib has significant anticancer activity in preclinical models.