Backstabbing P-gp: Side-Chain Cleaved Ecdysteroid 2,3-Dioxolanes Hyper-Sensitize MDR Cancer Cells to Doxorubicin without Efflux Inhibition
作者:Attila Hunyadi、József Csábi、Ana Martins、Joseph Molnár、Attila Balázs、Gábor Tóth
DOI:10.3390/molecules22020199
日期:——
P-glycoprotein (P-gp, ABCB1) over-expression, causing a multi-drug resistant (MDR) phenotype, is a major problem in cancer chemotherapy that urgently requires novel approaches. Our previous studies showed certain ecdysteroid derivatives as promising chemo-sensitizers against MDR and non-MDR cancer cell lines while also exerting mild to moderate inhibition of P-gp function. Here we report the preparation of a set of substituted 2,3-dioxolane derivatives of poststerone, a known in vivo metabolite of 20-hydroxyecdysone (20E). In contrast with previously studied ecdysteroid dioxolanes, the majority of the new compounds did not inhibit the efflux function of P-gp. Nevertheless, a strong, dose dependent sensitization to doxorubicin was observed on a P-gp transfected cancer cell line and on its susceptible counterpart. We also observed that the MDR cell line was more sensitive to the compounds’ effect than the non-MDR. Our results showed for the first time that the chemo-sensitizing activity of ecdysteroids can be fully independent of functional efflux pump inhibition, and suggest these compounds as favorable leads against MDR cancer.
P-糖蛋白(P-gp,ABCB1)的过度表达导致多药耐药(MDR)表型,这是癌症化疗中一个急需解决的主要问题。我们之前的研究显示某些蜕皮激素衍生物作为对抗MDR和非MDR癌细胞系的有前景的化疗增敏剂,同时对P-gp功能也有轻度至中度的抑制作用。在这里,我们报告了一系列取代的2,3-二氧烷衍生物的制备,这些衍生物是已知的20-羟基蜕皮激素(20E)的体内代谢物poststerone。与之前研究的蜕皮激素二氧烷相比,大多数新化合物并未抑制P-gp的外排功能。然而,在转染了P-gp的癌细胞系及其敏感性对应细胞系中观察到了强烈的、剂量依赖的对多柔比星的增敏作用。我们还观察到,MDR细胞系对这些化合物的影响比非MDR细胞系更为敏感。我们的结果首次表明,蜕皮激素的化疗增敏活性可以完全独立于功能外排泵的抑制,并建议这些化合物作为对抗MDR癌症的有利候选物。