Institute of Biochemistry and Signal Transduction, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Molecular Oncology and Immunotherapy, Department of General, Thoracic, Vascular and Transplantation Surgery, University of Rostock, Rostock, Germany.
Anticancer Res. 2021 May;41(5):2257-2275. doi: 10.21873/anticanres.15002.
Pre-therapeutic analysis of three-dimensional spheroid cultures of primary tumour samples is a promising approach of assessing susceptibility to potential treatment. The phosphatidylinositol-3-kinase/AKT serine/threonine kinase/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway is frequently activated in colorectal cancer (CRC). In previous work, we showed combined inhibition of AKT and mTOR to be highly synergistic in cell lines from patients with hepatocellular carcinoma and cholangiocarcinoma in vitro as well as in vivo in murine xenograft tumour models.
Patient-derived xenograft colorectal carcinoma cell lines HROC80 T1 M1, HROC147 T0 M1, HROC147Met, HROC277 T0 M1 and HROC277Met2 were treated with AKT inhibitor MK2206, mTOR inhibitor RAD001 or the combination of both drugs. The sensitivity of these cell lines to inhibition was evaluated by calculation of combinatory indices after bromodeoxyuridine assays and analysis of the respective pathways by western blotting. Furthermore, the dual inhibition of AKT and mTOR was confirmed in vivo in a xenograft mouse model. Additionally, primary CRC samples of four patients were embedded in a three-dimensional matrix and the sensitivity of these samples was analyzed by measurement of the spheroid area.
In this study, we demonstrate that combined treatment with MK2206 and RAD001 resulted in strong synergistic effects on growth of several primary CRC cell lines and reduced the growth of a patient-derived CRC xenograft in a xenotransplantation mouse model in vivo. Interestingly, the response to treatment varied between cell lines derived from the primary lesion and a liver metastasis of the same patient. In addition, combined treatment with AKT and mTOR inhibitors resulted in a synergistic inhibition of tumouroid growth in all four of the primary patient samples, analyzed in a three-dimensional spheroid model in vitro.
Our data demonstrate that combined treatment with AKT and mTOR inhibitors exhibits synergistic effects on proliferation of cell lines and primary tumour cells from patients with CRC and may be a promising approach for the treatment of CRC.
对原发性肿瘤样本的三维球体培养进行治疗前分析是评估潜在治疗敏感性的一种很有前途的方法。磷脂酰肌醇-3-激酶/丝氨酸-苏氨酸激酶/哺乳动物雷帕霉素靶蛋白（PI3K/AKT/mTOR）信号通路在结直肠癌（CRC）中经常被激活。在以前的工作中，我们发现在体外细胞系以及在小鼠异种移植肿瘤模型中，联合抑制 AKT 和 mTOR 对肝癌和胆管癌患者的细胞系具有高度协同作用。
患者来源的异种移植结直肠癌细胞系 HROC80 T1 M1、HROC147 T0 M1、HROC147Met、HROC277 T0 M1 和 HROC277Met2 用 AKT 抑制剂 MK2206、mTOR 抑制剂 RAD001 或两种药物联合治疗。通过溴脱氧尿苷测定计算组合指数，并通过 Western blot 分析各自的通路，评估这些细胞系对抑制的敏感性。此外，在异种移植小鼠模型中证实了 AKT 和 mTOR 的双重抑制作用。此外，还将四位患者的原发性 CRC 样本嵌入三维基质中，并通过测量球体面积来分析这些样本的敏感性。
在这项研究中，我们证明了 MK2206 和 RAD001 的联合治疗对几种原发性 CRC 细胞系的生长产生了强烈的协同作用，并在体内异种移植小鼠模型中减少了患者来源的 CRC 异种移植物的生长。有趣的是，来自原发性病变和同一患者肝转移的细胞系对治疗的反应不同。此外，在体外三维球体模型中分析来自四位患者的原发性样本时，联合使用 AKT 和 mTOR 抑制剂可协同抑制肿瘤球体的生长。
我们的数据表明，联合使用 AKT 和 mTOR 抑制剂对 CRC 患者的细胞系和原发性肿瘤细胞的增殖具有协同作用，可能是 CRC 治疗的一种有前途的方法。
