Quilles Junior José C, Carlos Fernanda Dos Reis Rocho, Montanari A, Leitão Andrei, Mignone Viviane W, Arruda Maria Augusta, Turyanska Lyudmila, Bradshaw Tracey D
Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham NG7 2RD UK
Medicinal Chemistry Group (NEQUIMED), São Carlos Institute of Chemistry (IQSC), University of São Paulo Av. Trabalhador São-carlense, 400, São Carlos SP 13.566-590 Brazil.
RSC Adv. 2019 Nov 11;9(63):36699-36706. doi: 10.1039/c9ra07161j.
Cysteine proteases play a key role in tumorigenesis causing protein degradation and promoting invasive tumour growth. Cathepsin L is overexpressed in cancer cells and could provide a specific target for delivery of anticancer agents. We encapsulated novel dipeptidyl nitrile based cysteine protease inhibitors (Neq0551, Neq0554 and Neq0568) into biocompatible apoferritin (AFt) protein nanocages to achieve specific delivery to tumours and pH-induced drug release. AFt-encapsulated Neq0554 demonstrated ∼3-fold enhanced activity (GI = 79 μM) compared to naked agent against MiaPaCa-2 pancreatic carcinoma cells. Selectivity for cancer cells was confirmed by comparing their activity to non-tumourigenic human fibroblasts (GI > 200 μM). Transferrin receptor (TfR-1) expression, detected only in lysates prepared from carcinoma cells, may contribute to the cancer-selectivity. The G cell cycle arrest caused by AFt-Neq0554 resulting in cytostasis was corroborated by clonogenic assays. Superior and more persistent inhibition of cathepsin L up to 80% was achieved with AFt-encapsulated agent in HCT-116 cells following 6 h exposure to 50 μM agent. The selective anticancer activity of AFt-encapsulated cysteine protease inhibitor Neq0554 reported here warrants further preclinical evaluation.
半胱氨酸蛋白酶在肿瘤发生过程中发挥关键作用，导致蛋白质降解并促进肿瘤侵袭性生长。组织蛋白酶L在癌细胞中过表达，可为抗癌药物的递送提供特定靶点。我们将新型基于二肽基腈的半胱氨酸蛋白酶抑制剂（Neq0551、Neq0554和Neq0568）封装到生物相容性脱铁铁蛋白（AFt）蛋白纳米笼中，以实现对肿瘤的特异性递送和pH诱导的药物释放。与游离药物相比，AFt封装的Neq0554对MiaPaCa-2胰腺癌细胞的活性增强了约3倍（GI = 79 μM）。通过将其活性与非致瘤性人成纤维细胞（GI > 200 μM）进行比较，证实了对癌细胞的选择性。仅在癌细胞制备的裂解物中检测到的转铁蛋白受体（TfR-1）表达可能有助于癌症选择性。克隆形成试验证实了AFt-Neq0554引起的G期细胞周期停滞导致细胞生长停滞。在50 μM药物处理6小时后，AFt封装的药物在HCT-116细胞中对组织蛋白酶L的抑制作用高达80%，具有更高的抑制效果和更持久的抑制作用。本文报道的AFt封装的半胱氨酸蛋白酶抑制剂Neq0554的选择性抗癌活性值得进一步进行临床前评估。
