Al-Thani Nayra M, Schaefer-Ramadan Stephanie, Aleksic Jovana, Mohamoud Yasmin A, Malek Joel A
Department of Genetic Medicine, Weill Cornell Medicine in Qatar, PO Box 24144, Doha, Qatar.
Department of Genomics and Precision Medicine, College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
Cancer Cell Int. 2022 Dec 1;22(1):376. doi: 10.1186/s12935-022-02799-1.
Colon cancer is often driven by mutations of the adenomatous polyposis coli (APC) gene, an essential tumor suppressor gene of the Wnt β-catenin signaling pathway. APC and its cytoplasmic interactions have been well studied. However, various groups have also observed its presence in the nucleus. Identifying novel interactions of APC in the Wnt pathway will provide an opportunity to understand APC's nuclear role better and ultimately identify potential cancer treatment targets.
We used the all-vs-all sequencing (AVA-Seq) method to interrogate the interactome of protein fragments spanning most of the 60 Wnt β-catenin pathway proteins. Using protein fragments identified the interacting regions between the proteins with more resolution than a full-length protein approach. Pull-down assays were used to validate a subset of these interactions.
74 known and 703 novel Wnt β-catenin pathway protein-protein interactions were recovered in this study. There were 8 known and 31 novel APC protein-protein interactions. Novel interactions of APC and nuclear transcription factors TCF7, JUN, FOSL1, and SOX17 were particularly interesting and confirmed in validation assays.
Based on our findings of novel interactions between APC and transcription factors and previous evidence of APC localizing to the nucleus, we suggest APC may compete and repress CTNNB1. This would occur through APC binding to the transcription factors (JUN, FOSL1, TCF7) to regulate the Wnt signaling pathway including through enhanced marking of CTNNB1 for degradation in the nucleus by APC binding with SOX17. Additional novel Wnt β-catenin pathway protein-protein interactions from this study could lead researchers to novel drug designs for cancer.
结肠癌通常由腺瘤性息肉病 coli（APC）基因的突变驱动，APC 是 Wntβ-连环蛋白信号通路中一种重要的肿瘤抑制基因。APC 及其胞质相互作用已得到充分研究。然而，多个研究小组也观察到它在细胞核中的存在。确定 APC 在 Wnt 通路中的新相互作用将为更好地理解 APC 的核作用提供机会，并最终确定潜在的癌症治疗靶点。
我们使用全对全测序（AVA-Seq）方法来探究涵盖 60 种 Wntβ-连环蛋白通路蛋白大部分的蛋白质片段的相互作用组。使用蛋白质片段比全长蛋白质方法能更精确地确定蛋白质之间的相互作用区域。下拉实验用于验证这些相互作用的一个子集。
本研究中发现了 74 种已知的和 703 种新的 Wntβ-连环蛋白通路蛋白-蛋白相互作用。有 8 种已知的和 31 种新的 APC 蛋白-蛋白相互作用。APC 与核转录因子 TCF7、JUN、FOSL1 和 SOX17 的新相互作用特别有趣，并在验证实验中得到证实。
基于我们对 APC 与转录因子之间新相互作用的发现以及 APC 定位于细胞核的先前证据，我们认为 APC 可能竞争并抑制 CTNNB1。这可能通过 APC 与转录因子（JUN、FOSL1、TCF7）结合来调节 Wnt 信号通路，包括通过 APC 与 SOX17 结合增强 CTNNB1 在细胞核中被降解的标记。本研究中其他新的 Wntβ-连环蛋白通路蛋白-蛋白相互作用可能会引导研究人员开发新的癌症药物设计。
