Departments of Molecular and Cellular Biochemistry (J.-A.Y., J.K., Y.-Y.B., W.P., M.P., S.K., T.K., S.C., K.-S.H., Y.-M.K.) and Neurobiology, School of Medicine (M.-H.W.), Departments of Biochemistry, College of Natural Sciences (D.J.) and Life Sciences, College of Natural Sciences (H.L.), and Kangwon Institute of Inclusive Technology (J.K., Y.-M.K.), Kangwon National University, Chuncheon, Gangwon-do, and Department of Anesthesiology and Pain Medicine, Hanyang University Hospital, Seoul (J.-Y.K.), and Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul (Y.-G.K.), Korea.
Departments of Molecular and Cellular Biochemistry (J.-A.Y., J.K., Y.-Y.B., W.P., M.P., S.K., T.K., S.C., K.-S.H., Y.-M.K.) and Neurobiology, School of Medicine (M.-H.W.), Departments of Biochemistry, College of Natural Sciences (D.J.) and Life Sciences, College of Natural Sciences (H.L.), and Kangwon Institute of Inclusive Technology (J.K., Y.-M.K.), Kangwon National University, Chuncheon, Gangwon-do, and Department of Anesthesiology and Pain Medicine, Hanyang University Hospital, Seoul (J.-Y.K.), and Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul (Y.-G.K.), Korea
Mol Pharmacol. 2019 Dec;96(6):692-701. doi: 10.1124/mol.119.117234. Epub 2019 Oct 8.
The tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a vascular endothelial growth factor (VEGF) receptor-2 antagonist, has been used previously either alone or in combination with chemotherapeutic drugs for treating colorectal cancer in a mouse model. We analyzed the half-life of the peptide and found that because of degradation by aminopeptidases B and N, it had a short half-life of 1.2 hours in the serum. Therefore, to increase the stability and potency of the peptide, we designed the modified peptide, N-terminally acetylated RLYE (Ac-RLYE), which had a strongly stabilized half-life of 8.8 hours in serum compared with the original parent peptide. The IC value of Ac-RLYE for VEGF-A-induced endothelial cell migration decreased to approximately 37.1 pM from 89.1 pM for the parent peptide. Using a mouse xenograft tumor model, we demonstrated that Ac-RLYE was more potent than RLYE in inhibiting tumor angiogenesis and growth, improving vascular integrity and normalization through enhanced endothelial cell junctions and pericyte coverage of the tumor vasculature, and impeding the infiltration of macrophages into tumor and their polarization to the M2 phenotype. Furthermore, combined treatment of Ac-RLYE and irinotecan exhibited synergistic effects on M1-like macrophage activation and apoptosis and growth inhibition of tumor cells. These findings provide evidence that the N-terminal acetylation augments the therapeutic effect of RLYE in solid tumors via inhibition of tumor angiogenesis, improvement of tumor vessel integrity and normalization, and enhancement of the livery and efficacy of the coadministered chemotherapeutic drugs. SIGNIFICANCE STATEMENT: The results of this study demonstrate that the N-terminal acetylation of the tetrapeptide RLYE (Ac-RLYE), a novel vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor, significantly improves its serum stability, antiangiogenic activity, and vascular normalizing potency, resulting in enhanced therapeutic effect on solid tumors. Furthermore, the combined treatment of Ac-RLYE with the chemotherapeutic drug, irinotecan, synergistically enhanced its antitumor efficacy by improving the perfusion and delivery of the drug into the tumors and stimulating the conversion of the tumor-associated macrophages to an immunostimulatory M1-like antitumor phenotype.
四肽 Arg-Leu-Tyr-Glu（RLYE）是一种血管内皮生长因子（VEGF）受体-2 拮抗剂，以前曾单独使用或与化疗药物联合用于治疗小鼠模型中的结直肠癌。我们分析了该肽的半衰期，发现由于氨基肽酶 B 和 N 的降解，它在血清中的半衰期只有 1.2 小时。因此，为了提高肽的稳定性和效力，我们设计了修饰肽，N-端乙酰化 RLYE（Ac-RLYE），与原始母体肽相比，它在血清中的半衰期得到了强烈的稳定，达到了 8.8 小时。Ac-RLYE 对 VEGF-A 诱导的内皮细胞迁移的 IC 值从母体肽的 89.1 pM 降低到约 37.1 pM。使用小鼠异种移植肿瘤模型，我们证明 Ac-RLYE 在抑制肿瘤血管生成和生长、改善血管完整性和正常化、增强内皮细胞连接和肿瘤血管周围周细胞覆盖、阻止巨噬细胞浸润肿瘤及其向 M2 表型极化方面比 RLYE 更有效。此外，Ac-RLYE 与伊立替康联合治疗对 M1 样巨噬细胞激活和肿瘤细胞凋亡以及生长抑制表现出协同作用。这些发现提供了证据，证明 N 端乙酰化通过抑制肿瘤血管生成、改善肿瘤血管完整性和正常化、增强共给药化疗药物的输送和疗效，增强了 RLYE 在实体瘤中的治疗效果。意义陈述：这项研究的结果表明，新型血管内皮生长因子受体-2（VEGFR-2）抑制剂四肽 RLYE（Ac-RLYE）的 N 端乙酰化显著提高了其血清稳定性、抗血管生成活性和血管正常化效力，从而增强了对实体瘤的治疗效果。此外，Ac-RLYE 与化疗药物伊立替康联合治疗通过改善药物向肿瘤的灌注和输送以及刺激肿瘤相关巨噬细胞向免疫刺激 M1 样抗肿瘤表型转化，协同增强了其抗肿瘤疗效。
