Two novel series of RGD-MEKI conjugates derived from a MEK1/2 kinase inhibitor—PD0325901—have been developed for integrin receptor mediated anticancer therapy. The first series, alkoxylamine analog RGD-MEKI conjugates 9a–g showed anti-proliferation activity in melanoma A375 cells by the same mechanism as that of PD0325901. PEGylation increased the IC50 value of 9f three-fold in the A375 assay, and the multi-cRGD peptide cargo significantly improved the receptor specific anti-proliferation activity of 9g in integrin-overexpressing U87 cells. In the second series, RGD-PD0325901 13 exhibited significantly increased antitumor properties compared to the alkoxylamine analogs by both inhibition of the ERK pathway activity and DNA replication of the cancer cells. Furthermore, 13 displayed more potent anti-proliferation activity in the U87 assay than PD0325901 in a dose-dependent manner. All these data demonstrate that RGD-MEKI conjugates with an ester bond linkage enhanced anticancer efficacy with improved targeting capability toward integrin-overexpressing tumor cells.
两种源于MEK1/2激酶
抑制剂PD0325901的新型RGD-MEKI偶联物系列已被开发用于整合素受体介导的癌症治疗。第一系列,烷氧基
胺类似物RGD-MEKI偶联物9a-g通过与PD0325901相同的机制在
黑色素瘤A375细胞中显示出抗增殖活性。P
EGylation使9f在A375测定中的IC50值增加了三倍,而多c
RGD肽负载则显著提高了9g在整合素高表达的U87细胞中的受体特异性抗增殖活性。在第二系列中,RGD-PD0325901 13相比烷氧基
胺类似物,通过抑制ERK通路活性和癌细胞的DNA复制,显示出显著增强的抗肿瘤特性。此外,13在U87测定中比PD0325901显示出更强的抗增殖活性,且呈剂量依赖性。所有这些数据表明,带有酯键连接的RGD-MEKI偶联物提高了对整合素高表达肿瘤细胞的靶向能力,从而增强了抗癌疗效。