Toh Yukimatsu, Wu Ling, Tu Jianghua, Liang Zhengdong, Aldana Adela M, Wen Jake J, Li Li, Pan Sheng, Rowe Julie H, Hensel Martha E, Hodo Carolyn L, Finch Rick A, Carmon Kendra S, Liu Qingyun J
Center for Translational Cancer Research, Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
Br J Cancer. 2025 Aug 18. doi: 10.1038/s41416-025-03121-2.
Antibody-drug conjugates (ADCs) are a significant advancement in targeted cancer therapy, but none are approved for colorectal cancer (CRC). LGR4/5/6, highly expressed in most CRCs, are promising targets. While LGR5-targeting ADCs show strong anti-tumor effects, their efficacy is limited by LGR5 loss in some CRC cells. RSPO4, a natural ligand for LGR4/5/6, binds all three receptors with high affinity. This research develops RSPO4-based peptibody drug-conjugates (PDCs) to simultaneously target LGR4/5/6, offering a novel therapeutic approach for CRC.
LGR4/5/6 expression in CRCs was analysed using RNA-seq datasets and Western blot. Peptibody binding affinities were measured, conjugated to camptothecin analog, CPT2, and tested for cytotoxicity in CRC cell lines. Antitumor efficacy was evaluated in vivo using CRC cell line and patient-derived xenograft (PDX) models.
Peptibody was engineered by fusing a mutant RSPO4 furin-domain to human IgG1 Fc, retaining high-affinity LGR4/5/6 binding without enhancing Wnt/β-catenin signalling. Conjugated with CPT2 molecules, the PDC showed strong antitumor activity in CRC cell lines and dose-dependent tumor growth inhibition in xenograft and patient-derived models.
Preclinical data showed that LGR4/5/6-targeting PDC exhibited potent cytotoxicity in vitro and robust antitumor efficacy in CRC xenograft and PDX models, making its potential as a promising therapeutic approach for CRC.
抗体药物偶联物（ADC）是靶向癌症治疗的一项重大进展，但尚无获批用于结直肠癌（CRC）的产品。LGR4/5/6在大多数CRC中高表达，是很有前景的靶点。虽然靶向LGR5的ADC显示出强大的抗肿瘤作用，但其疗效受到一些CRC细胞中LGR5缺失的限制。RSPO4是LGR4/5/6的天然配体，能与所有三种受体高亲和力结合。本研究开发了基于RSPO4的肽抗体药物偶联物（PDC）以同时靶向LGR4/5/6，为CRC提供了一种新的治疗方法。
使用RNA测序数据集和蛋白质免疫印迹分析CRC中LGR4/5/6的表达情况。测定肽抗体的结合亲和力，将其与喜树碱类似物CPT2偶联，并在CRC细胞系中测试细胞毒性。使用CRC细胞系和患者来源的异种移植（PDX）模型在体内评估抗肿瘤疗效。
通过将突变的RSPO4弗林蛋白酶结构域与人IgG1 Fc融合构建肽抗体，并保留了对LGR4/5/6的高亲和力结合，且不增强Wnt/β-连环蛋白信号传导。与CPT2分子偶联后，PDC在CRC细胞系中显示出强大的抗肿瘤活性，并在异种移植和患者来源模型中呈现剂量依赖性的肿瘤生长抑制作用。
临床前数据表明，靶向LGR4/5/6的PDC在体外表现出强大的细胞毒性，在CRC异种移植和PDX模型中具有强大的抗肿瘤疗效使其有望成为CRC的一种有前景的治疗方法。
