To investigate the collateral sensitivity (CS) of ABCB1-positive multidrug resistant (MDR) colorectal cancer cells to the survivin inhibitor MX106–4C and the mechanism. Biochemical assays (MTT, ATPase, drug accumulation/efflux, Western blot, RT-qPCR, immunofluorescence, flow cytometry) and bioinformatic analyses (mRNA-sequencing, reversed-phase protein array) were performed to investigate the hypersensitivity of ABCB1 overexpressing colorectal cancer cells to MX106–4C and the mechanisms. Synergism assay, long-term selection, and 3D tumor spheroid test were used to evaluate the anti-cancer efficacy of MX106–4C. MX106–4C selectively killed ABCB1-positive colorectal cancer cells, which could be reversed by an ABCB1 inhibitor, knockout of ABCB1, or loss-of-function ABCB1 mutation, indicating an ABCB1 expression and function-dependent mechanism. MX106–4C's selective toxicity was associated with cell cycle arrest and apoptosis through ABCB1-dependent survivin inhibition and activation on caspases-3/7 as well as modulation on p21-CDK4/6-pRb pathway. MX106–4C had good selectivity against ABCB1-positive colorectal cancer cells and retained this in multicellular tumor spheroids. In addition, MX106–4C could exert a synergistic anti-cancer effect with doxorubicin or re-sensitize ABCB1-positive cancer cells to doxorubicin by reducing ABCB1 expression in the cell population via long-term exposure. MX106–4C selectively kills ABCB1-positive MDR colorectal cancer cells via a novel ABCB1-dependent survivin inhibition mechanism, providing a clue for designing CS compound as an alternative strategy to overcome ABCB1-mediated colorectal cancer MDR.

中文翻译：

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多重耐药结直肠癌细胞对生存素抑制剂 MX106-4C 的 ABCB1 依赖性附带敏感性


探讨ABCB1阳性多药耐药（MDR）结直肠癌细胞对生存素抑制剂MX106–4C的附带敏感性（CS）及其机制。进行生化测定（MTT、ATPase、药物累积/流出、Western blot、RT-qPCR、免疫荧光、流式细胞术）和生物信息学分析（mRNA 测序、反相蛋白阵列）来研究 ABCB1 过表达结直肠癌细胞的超敏性MX106–4C 及其机制。采用协同作用测定、长期选择和3D肿瘤球体测试来评估MX106–4C的抗癌功效。 MX106-4C 选择性杀死 ABCB1 阳性结直肠癌细胞，这种情况可以通过 ABCB1 抑制剂、ABCB1 敲除或 ABCB1 功能丧失突变来逆转，表明 ABCB1 表达和功能依赖性机制。 MX106–4C 的选择性毒性通过 ABCB1 依赖性生存素抑制和激活 caspase-3/7 以及调节 p21-CDK4/6-pRb 途径与细胞周期停滞和细胞凋亡相关。 MX106-4C 对 ABCB1 阳性结直肠癌细胞具有良好的选择性，并将其保留在多细胞肿瘤球体中。此外，MX106-4C可以与阿霉素发挥协同抗癌作用，或者通过长期暴露减少细胞群中ABCB1的表达，使ABCB1阳性癌细胞对阿霉素重新敏感。 MX106–4C 通过一种新型 ABCB1 依赖性生存素抑制机制选择性杀死 ABCB1 阳性 MDR 结直肠癌细胞，为设计 CS 化合物作为克服 ABCB1 介导的结直肠癌 MDR 的替代策略提供了线索。