Institute for Biological Research "Siniša Stanković", University of Belgrade, Despota Stefana 142, Belgrade, 11060, Serbia.
Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Biopolis, 41110, Larissa, Greece.
Cell Oncol (Dordr). 2018 Aug;41(4):409-426. doi: 10.1007/s13402-018-0380-x. Epub 2018 May 22.
Anaplastic thyroid carcinoma (ATC) is an aggressive, chemo-resistant malignancy. Chemo-resistance is often associated with changes in activity of the RAS/MAPK/ERK and PI3K/AKT/mTOR pathways and/or a high expression of ATP binding cassette (ABC) transporters, such as P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). To assess the therapeutic efficacy in ATC of a combination of the dual mTOR kinase inhibitor vistusertib (AZD2014) and paclitaxel (PTX), we generated a new cell line (Rho-) via the selection of human thyroid carcinoma 8505C cells that exhibit a low accumulation of rhodamine 123, which serves as a P-gp and BCRP substrate.
Immunohistochemistry was used for P-gp and BCRP expression analyses in primary ATC patient samples. Spheroid formation and immunodeficient NSG mice were used for performing in vitro and in vivo tumorigenicity assays, respectively. MTT, flow-cytometry, fluorescent microscopy, cell death and proliferation assays, as well as migration, invasion and gelatin degradation assays, were used to assess the potential of AZD2014 to enhance the effects of PTX. ATC xenografts in SCID mice were used for evaluating in vivo treatment efficacies.
Rho- cells were found to be 10-fold more resistant to PTX than 8505C cells and, in addition, to be more tumorigenic. We also found that AZD2014 sensitized Rho- cells to PTX by inhibiting proliferation and by inducing autophagy. The combined use of AZD2014 and PTX efficiently inhibited in vitro ATC cell migration and invasion. Subsequent in vivo xenograft studies indicated that the AZD2014 and PTX combination effectively suppressed ATC tumor growth.
Our data support results from recent phase I clinical trials using combinations of AZD2014 and PTX for the treatment of solid tumors. Such combinations may also be employed for the design of novel targeted ATC treatment strategies.
间变性甲状腺癌（ATC）是一种侵袭性、化疗耐药的恶性肿瘤。化疗耐药通常与 RAS/MAPK/ERK 和 PI3K/AKT/mTOR 通路活性的变化以及 ABC 转运蛋白（如 P-糖蛋白（P-gp）和乳腺癌耐药蛋白（BCRP））的高表达有关。为了评估双重 mTOR 激酶抑制剂 vistusertib（AZD2014）和紫杉醇（PTX）联合治疗 ATC 的疗效，我们通过选择人甲状腺癌细胞系 8505C 生成了一个新的细胞系（Rho-），该细胞系对 rhodamine 123 的积累较低， rhodamine 123 是 P-gp 和 BCRP 的底物。
使用免疫组织化学分析原发性 ATC 患者样本中 P-gp 和 BCRP 的表达。使用球体形成和免疫缺陷 NSG 小鼠分别进行体外和体内致瘤性测定。MTT、流式细胞术、荧光显微镜、细胞死亡和增殖测定以及迁移、侵袭和明胶降解测定用于评估 AZD2014 增强 PTX 作用的潜力。SCID 小鼠中的 ATC 异种移植物用于评估体内治疗效果。
与 8505C 细胞相比，Rho-细胞对 PTX 的耐药性增加了 10 倍，并且具有更强的致瘤性。我们还发现，AZD2014 通过抑制增殖和诱导自噬来使 Rho-细胞对 PTX 敏感。AZD2014 和 PTX 的联合使用可有效抑制体外 ATC 细胞的迁移和侵袭。随后的体内异种移植研究表明，AZD2014 和 PTX 联合有效抑制了 ATC 肿瘤的生长。
我们的数据支持最近使用 AZD2014 和 PTX 联合治疗实体瘤的 I 期临床试验结果。这种联合用药也可用于设计新的靶向 ATC 治疗策略。
