结直肠癌（CRC）是癌症相关死亡的主要原因，其中大多数病例由APC肿瘤抑制基因的失活引发。这导致经典WNT途径转录效应子β-连接蛋白的构成性活化，以及诱导WNT反馈抑制物质，包括细胞外棕榈油基蛋白羧酯酶NOTUM，该酶能对抗WNT-FZD受体和配体的相互作用。在本文中，我们试图评估NOTUM活性对CRC的影响，其作为驱动突变谱的一部分。用CRC驱动突变的组合制备了小鼠和人类结肠器官样聚集体，并用于Notum基因增强功能和基因失活功能研究。采用体外实验、体内内窥镜引导的原位器官样聚集体植入试验和转录组学分析来表征Notum活性的效应。使用Notum活性的小分子抑制剂进行临床前治疗的概念证明研究，以靶向致瘤Notum活性。尽管存在构成性β-连接蛋白活性，NOTUM仍保持在APC敲除腺瘤中的肿瘤抑制活性。引人注目的是，在伴有P53损失的腺癌进展中，NOTUM成为一种必需的癌基因。这些表型与Wnt途径无关，分别是由于早期和晚期疾病中NOTUM对糖基肽1和4的差异活性所致。最终，临床前小鼠模型和人类器官样聚集体研究表明，药物抑制NOTUM在抑制原发性腺癌生长和抑制远端器官转移定植方面具有很高的效果。我们的发现表明，靶向细胞外酶NOTUM的单一药物在治疗高侵袭性、转移性腺癌方面，在临床前小鼠模型和人类器官样聚集体中具有显著疗效，这使得NOTUM及其糖基肽靶点成为晚期CRC的治疗易感性。 © 作者（或其雇主）2023年。依据CC BY-NC许可此重复使用。BMJ出版。

Colorectal cancer (CRC) is a leading cause of cancer-related deaths, with the majority of cases initiated by inactivation of the APC tumour suppressor. This results in the constitutive activation of canonical WNT pathway transcriptional effector ß-catenin, along with induction of WNT feedback inhibitors, including the extracellular palmitoleoyl-protein carboxylesterase NOTUM which antagonises WNT-FZD receptor-ligand interactions. Here, we sought to evaluate the effects of NOTUM activity on CRC as a function of driver mutation landscape.Mouse and human colon organoids engineered with combinations of CRC driver mutations were used for Notum genetic gain-of-function and loss-of-function studies. In vitro assays, in vivo endoscope-guided orthotopic organoid implantation assays and transcriptomic profiling were employed to characterise the effects of Notum activity. Small molecule inhibitors of Notum activity were used in preclinical therapeutic proof-of-principle studies targeting oncogenic Notum activity.NOTUM retains tumour suppressive activity in APC-null adenomas despite constitutive ß-catenin activity. Strikingly, on progression to adenocarcinoma with P53 loss, NOTUM becomes an obligate oncogene. These phenotypes are Wnt-independent, resulting from differential activity of NOTUM on glypican 1 and 4 in early-stage versus late-stage disease, respectively. Ultimately, preclinical mouse models and human organoid cultures demonstrate that pharmacological inhibition of NOTUM is highly effective in arresting primary adenocarcinoma growth and inhibiting metastatic colonisation of distal organs.Our findings that a single agent targeting the extracellular enzyme NOTUM is effective in treating highly aggressive, metastatic adenocarcinomas in preclinical mouse models and human organoids make NOTUM and its glypican targets therapeutic vulnerabilities in advanced CRC.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.