Targeting epidermal growth factor receptor (EGFR) with tyrosine kinase inhibitors (TKI) has been widely exploited to disrupt aberrant phosphorylation flux in cancer. However, a bottleneck of potent TKIs is the acquisition of drug resistance mutations, secondary effects, and low ability to attenuate tumor progression. We have developed an alternative means of targeting EGFR that relies on protein degradation through two consecutive routes, ultimately leading to cancer cell detachment-related death. We describe furfuryl derivatives of 4-allyl-5-[2-(4-alkoxyphenyl)-quinolin-4-yl]-4H-1,2,4-triazole-3-thiol that bind to and weakly inhibit EGFR tyrosine phosphorylation and induce strong endocytic degradation of the receptor in cancer cells. The compound-promoted depletion of EGFR resulted in the sequestration of non-phosphorylated Bim, which no longer ensured the integrity of the cytoskeleton machinery, as shown by the detachment of cancer cells from the extracellular matrix (ECM). Of particular note, the longer CH3(CH2)n chains in the terminal moiety of the anti-EGFR molecules confer higher hydrophobicity in the allosteric site located in the immediate vicinity of the catalytic pocket. Small compounds accelerated and enhanced EGFR and associated proteins degradation during EGF and/or glutamine starvation of cultures, thereby demonstrating high potency in killing cancer cells by simultaneously modulating signaling and metabolic pathways. We propose a plausible mechanism of anti-cancer action by small degraders through the allosteric site of EGFR. Our data represent a rational and promising perspective in the treatment of aggressive tumors.
通过酪氨酸激酶抑制剂(TKI)针对表皮生长因子受体(EGFR)已被广泛利用来破坏癌症中异常的磷酸化通路。然而,强效TKI的瓶颈在于获得药物抗性突变、次生效应和低能力减缓肿瘤进展。我们已经开发了一种替代手段,通过两个连续的途径来靶向EGFR的蛋白质降解,最终导致癌细胞脱落相关的死亡。我们描述了4-丙烯基-5-[2-(4-烷氧基苯基)-喹啉-4-基]-4H-1,2,4-三唑-3-硫醇的呋喃基衍生物,它们结合并微弱抑制EGFR酪氨酸磷酸化,并在癌细胞中诱导强烈的内吞降解受体。化合物促进EGFR的消耗导致非磷酸化Bim的隔离,它不再确保细胞骨架机械的完整性,如癌细胞从细胞外基质(ECM)中脱落所示。特别值得注意的是,抗EGFR分子中端基团中更长的CH3(CH2)n链在催化口袋附近的变构位点中赋予更高的疏水性。小分子化合物在EGF和/或谷氨酰胺饥饿的培养条件下加速和增强EGFR及其相关蛋白的降解,从而通过同时调节信号和代谢途径展示了高杀伤癌细胞的效能。我们提出了小型去除剂通过EGFR的变构位点对抗癌作用的可能机制。我们的数据代表了治疗侵袭性肿瘤的合理和有前途的观点。