Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, PR China.
Institute of Digestive Disease, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong SAR, PR China.
J Pathol. 2023 Feb;259(2):205-219. doi: 10.1002/path.6033. Epub 2022 Dec 17.
Colorectal cancer (CRC) is one of the most common cancers worldwide. The tumor microenvironment exerts crucial effects in driving CRC progression. Cancer-associated fibroblasts (CAFs) serve as one of the most important tumor microenvironment components promoting CRC progression. This study aimed to elucidate the novel molecular mechanisms of CAF-secreted insulin-like growth factor (IGF) 2 in colorectal carcinogenesis. Our results indicated that IGF2 was a prominent factor upregulated in CAFs compared with normal fibroblasts. CAF-derived conditioned media (CM) promoted tumor growth, migration, and invasion of HCT 116 and DLD-1 cells. IGF1R expression is significantly increased in CRC, serving as a potent receptor in response to IGF2 stimulation and predicting unfavorable outcomes for CRC patients. Apart from the PI3K-AKT pathway, RNA-seq analysis revealed that the YAP1-target signature serves as a prominent downstream effector to mediate the oncogenic signaling of IGF2-IGF1R. By single-cell RNA sequencing (scRNA-seq) and immunohistochemical validation, IGF2 was found to be predominantly secreted by CAFs, whereas IGF1R was expressed mainly by cancer cells. IGF2 triggers the nuclear accumulation of YAP1 and upregulates YAP1 target signatures; however, these effects were abolished by either IGF1R knockdown or inhibition with picropodophyllin (PPP), an IGF1R inhibitor. Using CRC organoid and in vivo studies, we found that cotargeting IGF1R and YAP1 with PPP and verteporfin (VP), a YAP1 inhibitor, enhanced antitumor effects compared with PPP treatment alone. In conclusion, this study revealed a novel molecular mechanism by which CAFs promote CRC progression. The findings highlight the translational potential of the IGF2-IGF1R-YAP1 axis as a prognostic biomarker and therapeutic target for CRC. © 2022 The Pathological Society of Great Britain and Ireland.
结直肠癌(CRC)是全球最常见的癌症之一。肿瘤微环境在推动 CRC 进展方面发挥着至关重要的作用。癌相关成纤维细胞(CAFs)是促进 CRC 进展的最重要的肿瘤微环境成分之一。本研究旨在阐明 CAF 分泌的胰岛素样生长因子(IGF)2 在结直肠发生中的新的分子机制。我们的研究结果表明,与正常成纤维细胞相比,IGF2 是 CAF 中上调最显著的因子之一。CAF 衍生的条件培养基(CM)促进 HCT 116 和 DLD-1 细胞的肿瘤生长、迁移和侵袭。IGF1R 在 CRC 中表达显著增加,作为对 IGF2 刺激的有效受体,预测 CRC 患者的不良结局。除了 PI3K-AKT 通路外,RNA-seq 分析还表明,YAP1 靶基因签名作为介导 IGF2-IGF1R 致癌信号的重要下游效应子。通过单细胞 RNA 测序(scRNA-seq)和免疫组织化学验证,发现 IGF2 主要由 CAFs 分泌,而 IGF1R 主要由癌细胞表达。IGF2 触发 YAP1 的核积累并上调 YAP1 靶基因签名;然而,这些效应被 IGF1R 敲低或 IGF1R 抑制剂 picropodophyllin(PPP)抑制所消除。使用 CRC 类器官和体内研究,我们发现用 PPP 和 YAP1 抑制剂 verteporfin(VP)联合靶向 IGF1R 和 YAP1,与单独用 PPP 治疗相比,增强了抗肿瘤作用。总之,本研究揭示了 CAFs 促进 CRC 进展的新的分子机制。这些发现强调了 IGF2-IGF1R-YAP1 轴作为 CRC 预后生物标志物和治疗靶点的转化潜力。