间变性甲状腺癌（ATC）具有统一的致命性。BRAFV600E突变在高达45%的ATC患者中存在。针对BRAFV600E突变ATC的BRAF和MEK联合抑制靶向治疗可以有效，但由于该联合策略靶向相同通路，因此常常出现获得性耐药。在BRAFV600E ATC细胞中进行药物组合筛选，发现多靶酪氨酸激酶抑制剂（MTKI）具有最高的协同/附加活性。因此，我们假设与单药或联合BRAF和MEK抑制相比，BRAFV600E抑制与MTKI的联合更加有效用于BRAFV600E突变ATC。我们评估了与MTKI axitinib的BRAFV600E抑制剂的联合效应及其作用机制。我们在BRAFV600E突变和野生型ATC的体外和体内模型中评估了BRAFV600E抑制剂和axitinib单独和联合的效应。在BRAFV600E突变ATC细胞系中，axitinib和BRAFV600E抑制剂（dabrafenib和PLX4720）的联合根据Chou-Talalay算法表现出加成效应，抑制细胞增殖。与对照组相比，该组合还显著抑制了细胞侵袭和迁移（P < 0.001）。Dabrafenib和PLX4720使ATC细胞停滞在G0/G1期。通过降低aurora激酶B（Thr232）和histone H3（Ser10）蛋白的磷酸化水平，并上调c-JUN信号通路，axitinib使ATC细胞停滞在G2/M期。BRAF抑制与axitinib的联合显著抑制了肿瘤生长，并与正转位型ATC模型中的生存率改善相关。axitinib和BRAFV600E抑制剂的新型联合增强了BRAFV600E突变ATC的体内外抗癌活性。该联合疗法可能对于目前标准治疗即BRAF和MEK联合抑制无效的BRAFV600E突变ATC具有临床应用价值。

Anaplastic thyroid cancer (ATC) is uniformly lethal. BRAFV600E mutation is present in up to 45% of patients with ATC. Targeted therapy with combined BRAF and MEK inhibition in BRAFV600E-mutant ATC can be effective, but acquired resistance is common because this combination targets the same pathway. Drug matrix screening, in BRAFV600E ATC cells, of highly active compounds in combination with BRAF inhibition showed multitargeting tyrosine kinase inhibitors (MTKIs) had the highest synergistic/additive activity. Thus, we hypothesized that the combination of BRAFV600E inhibition and an MTKI is more effective than a single drug or combined BRAF and MEK inhibition in BRAFV600E-mutant ATC. We evaluated the effect of BRAFV600E inhibitors in combination with the MTKI axitinib and its mechanism(s) of action.We evaluated the effects of BRAFV600E inhibitors and axitinib alone and in combination in in vitro and in vivo models of BRAFV600E-mutant and wildtype ATC.The combination of axitinib and BRAFV600E inhibitors (dabrafenib and PLX4720) showed an additive effect on inhibiting cell proliferation based on the Chou-Talalay algorithm in BRAFV600E-mutant ATC cell lines. This combination also significantly inhibited cell invasion and migration (P < 0.001) compared with the control. Dabrafenib and PLX4720 arrested ATC cells in the G0/G1 phase. Axitinib arrested ATC cells in the G2/M phase by decreasing phosphorylation of aurora kinase B (Thr232) and histone H3 (Ser10) proteins and by upregulating the c-JUN signaling pathway. The combination of BRAF inhibition and axitinib significantly inhibited tumor growth and was associated with improved survival in an orthotopic ATC model.The novel combination of axitinib and BRAFV600E inhibition enhanced anticancer activity in in vitro and in vivo models of BRAFV600E-mutant ATC. This combination may have clinical utility in BRAFV600E-mutant ATC that is refractory to current standard therapy, namely combined BRAF and MEK inhibition.