Notch1 activation triggers significant oncogenic signaling that manifests as enhanced metastatic potential and tumorigenesis in colorectal cancer. Novel small-molecule inhibitors, mainly plant-derived analogs, have low toxicity profiles and higher bioavailability. In this study, we have developed a small molecule, ASR490, by modifying structure of naturally occurring compound Withaferin A. ASR490 showed a growth-inhibitory potential by downregulating Notch1 signaling in HCT116 and SW620 cell lines. Docking studies and thermal shift assays confirmed that ASR490 binds to Notch1, whereas no changes in Notch2 and Notch3 expression were seen in colorectal cancer cells. Notch1 governs epithelial-to-mesenchymal transition signaling and is responsible for metastasis, which was abolished by ASR490 treatment. To further confirm the therapeutic potential of ASR490, we stably overexpressed Notch1 in HCT-116 cells and determined its inhibitory potential in transfected colorectal cancer (Notch1/HCT116) cells. ASR490 effectively prevented cell growth in both the vector (P = 0.005) and Notch1 (P = 0.05) transfectants. The downregulation of Notch1 signaling was evident, which corresponded with downregulation of mesenchymal markers, including N-cadherin and β-catenin and induction of E-cadherin in HCT-116 transfectants. Intraperitoneal administration of a 1% MTD dose of ASR490 (5 mg/kg) effectively suppressed the tumor growth in control (pCMV/HCT116) and Notch1/HCT116 in xenotransplanted mice. In addition, downregulation of Notch1 and survival signaling in ASR-treated tumors confirmed the in vitro results. In conclusion, ASR490 appears to be a potent agent that can inhibit Notch1 signaling in colorectal cancer.

中文翻译：

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ASR490 是一种小分子，可抑制结直肠癌中 Notch1 的异常表达。

Notch1 激活会触发显着的致癌信号，表现为结直肠癌的转移潜力和肿瘤发生增强。新型小分子抑制剂，主要是植物来源的类似物，具有低毒性和更高的生物利用度。在这项研究中，我们通过修饰天然化合物 Withaferin A 的结构开发了一种小分子 ASR490。ASR490 通过下调 HCT116 和 SW620 细胞系中的 Notch1 信号传导而显示出生长抑制潜力。对接研究和热位移测定证实 ASR490 与 Notch1 结合，而结直肠癌细胞中 Notch2 和 Notch3 表达没有变化。Notch1 控制上皮到间质的转变信号并负责转移，但 ASR490 治疗消除了这种转移。为了进一步证实ASR490的治疗潜力，我们在HCT-116细胞中稳定过表达Notch1，并确定其在转染的结直肠癌（Notch1/HCT116）细胞中的抑制潜力。ASR490 有效阻止载体 (P = 0.005) 和 Notch1 (P = 0.05) 转染子中的细胞生长。Notch1 信号传导的下调是明显的，这与间充质标志物（包括 N-钙粘蛋白和 β-连环蛋白）的下调以及 HCT-116 转染子中 E-钙粘蛋白的诱导相对应。腹膜内施用 1% MTD 剂量的 ASR490 (5 mg/kg) 可有效抑制对照 (pCMV/HCT116) 和异种移植小鼠中 Notch1/HCT116 的肿瘤生长。此外，ASR 治疗的肿瘤中 Notch1 和生存信号的下调证实了体外结果。总之，ASR490 似乎是一种有效的药物，可以抑制结直肠癌中的 Notch1 信号传导。