Ghosh Susmita, Fan Fan, Powell Reid, Park Yong, Stephan Clifford, Kopetz E Scott, Ellis Lee M, Bhattacharya Rajat
bioRxiv. 2024 Sep 6:2024.09.05.611458. doi: 10.1101/2024.09.05.611458.
is frequently mutated in the tumors of patients with metastatic colorectal cancer (mCRC) and thus represents a valid target for therapy. However, the strategies of targeting KRAS directly and targeting the downstream effector mitogen-activated protein kinase kinase (MEK) via monotherapies have shown limited efficacy. Thus, there is a strong need for novel, effective combination therapies to improve MEK-inhibitor efficacy in patients with -mutated mCRC.
Our objective was to identify novel drug combinations that enhance MEK-inhibitor efficacy in patients with -mutated mCRC.
In this study, we performed unbiased high-throughput screening (HTS) to identify drugs that enhance the efficacy of MEK inhibitors , and we validated the efficacy of the drugs .
HTS was performed using 3-dimensional CRC spheroids. Trametinib, the anchor drug, was probed with 2 clinically ready libraries of 252 drugs to identify effective drug combinations. The effects of the drug combinations on CRC cell proliferation and apoptosis were further validated using cell growth assays, flow cytometry, and biochemical assays. Proteomic and immunostaining studies were performed to determine the effects of the drugs on molecular signaling and cell division. The effects of the drug combinations were examined using CRC patient-derived xenografts.
HTS identified paclitaxel as being synergistic with trametinib. validation showed that, compared with monotherapies, this drug combination demonstrated strong inhibition of cell growth, reduced colony formation, and enhanced apoptosis in multiple -mutated CRC cell lines. Mechanistically, combining trametinib with paclitaxel led to alterations in signaling mediators that block cell cycle progression and increases in microtubule stability that resulted in significantly higher defects in the mitosis. Finally, the combination of trametinib with paclitaxel exhibited significant inhibition of tumor growth in several -mutant patient-derived xenograft mouse models.
Our data provide evidence supporting clinical trials of trametinib with paclitaxel as a novel therapeutic option for patients with -mutated, metastatic CRC.
在转移性结直肠癌（mCRC）患者的肿瘤中经常发生突变，因此是一个有效的治疗靶点。然而，直接靶向KRAS以及通过单一疗法靶向下游效应分子丝裂原活化蛋白激酶激酶（MEK）的策略显示出有限的疗效。因此，迫切需要新的、有效的联合疗法来提高MEK抑制剂对KRAS突变型mCRC患者的疗效。
我们的目的是确定能增强MEK抑制剂对KRAS突变型mCRC患者疗效的新型药物组合。
在本研究中，我们进行了无偏倚的高通量筛选（HTS）以确定能增强MEK抑制剂疗效的药物，并验证了这些药物的疗效。
使用三维CRC球体进行HTS。以曲美替尼为锚定药物，与2个包含252种药物的临床可用文库进行筛选，以确定有效的药物组合。使用细胞生长试验、流式细胞术和生化试验进一步验证药物组合对CRC细胞增殖和凋亡的影响。进行蛋白质组学和免疫染色研究以确定药物对分子信号传导和细胞分裂的影响。使用CRC患者来源的异种移植模型研究药物组合的效果。
HTS确定紫杉醇与曲美替尼具有协同作用。验证表明，与单一疗法相比，这种药物组合在多个KRAS突变的CRC细胞系中表现出对细胞生长的强烈抑制、集落形成减少和凋亡增强。从机制上讲，曲美替尼与紫杉醇联合导致信号传导介质改变，阻断细胞周期进程，并增加微管稳定性，导致有丝分裂中的缺陷显著增加。最后，曲美替尼与紫杉醇的组合在几个KRAS突变的患者来源的异种移植小鼠模型中表现出对肿瘤生长的显著抑制。
我们的数据为曲美替尼与紫杉醇联合作为KRAS突变型转移性CRC患者的新型治疗选择的临床试验提供了证据支持。
