ULK-101 is a selective ULK1 inhibitor (IC₅₀=1.6nM) that inhibits ULK2 activity (IC₅₀=30nM). ULK-101 blocks cellular autophagy by inhibiting both autophagy induction and autophagic flux[1-2]. ULK-101 can be used in research related to autophagy mechanisms and cancer, particularly KRAS-mutant lung cancer[3-4].
In vitro, U2OS cells were pretreated with ULK-101 (5μM) for 2.5 hours and then stimulated with AZD8055 (100nM). ULK-101 significantly inhibited the formation of DFCP1-positive puncta and ATG12-positive phagophores. In another experiment, cells were treated with ULK-101 (5μM) for 3 hours, with BafA1 (100nM) added for the final 1.5 hours. This treatment significantly inhibited the accumulation of LC3B-positive vesicles[5]. A549, H1299, and Mv1Lu cells were pretreated with ULK-101 (1μM) for 24 hours and then stimulated with TGFβ1 (250pM). ULK-101 significantly inhibited the trafficking of cell-surface TGFβ receptors to early endosomes, late endosomes, and lysosomes. ULK-101 reduced TGFβ1-induced Smad2/Smad3 phosphorylation, nuclear translocation, expression of epithelial-mesenchymal transition (EMT) markers (N-cadherin, Slug, Snail), stress fiber formation, and cell migration[6].
In vivo, wild-type (WT) mice with house dust mite (HDM)-induced asthma were administered ULK-101 (20mg/kg) via daily intraperitoneal injection for 10 days. ULK-101 administration significantly inhibited the activation of the ULK1/Atg9a signaling pathway and reduced the expression of the NLRP3 inflammasome and its downstream effector molecules, caspase-1 and IL-1β, in lung tissues[7].
References:
[1] Hou W, Xiao C, Zhou R, et al. Inhibiting autophagy selectively prunes dysfunctional tumor vessels and optimizes the tumor immune microenvironment. Theranostics. 2025 Jan 1;15(1):258-276.
[2] Jaeger-Ruckstuhl CA, Lo Y, Fulton E, et al. Signaling via a CD27-TRAF2-SHP-1 axis during naive T cell activation promotes memory-associated gene regulatory networks. Immunity. 2024 Feb 13;57(2):287-302.e12.
[3] Ikeda R, Noshiro D, Morishita H, et al. Phosphorylation of phase-separated p62 bodies by ULK1 activates a redox-independent stress response. EMBO J. 2023 Jul 17;42(14):e113349.
[4] Tian MY, Yang JQ, Hu JC, et al. Semaglutide administration protects cardiomyocytes in db/db mice via energetic improvement and mitochondrial quality control. Acta Pharmacol Sin. 2025 May;46(5):1250-1261.
[5] Martin KR, Celano SL, Solitro AR, et al. A Potent and Selective ULK1 Inhibitor Suppresses Autophagy and Sensitizes Cancer Cells to Nutrient Stress. iScience. 2018 Oct 26;8:74-84.
[6] Trelford CB, Di Guglielmo GM. Autophagy regulates transforming growth factor β signaling and receptor trafficking. Biochim Biophys Acta Mol Cell Res. 2022 Sep;1869(9):119284.
[7] Xu C, Song Y, Liu W, et al. IL-4 activates ULK1/Atg9a/Rab9 in asthma, NLRP3 inflammasomes, and Golgi fragmentation by increasing autophagy flux and mitochondrial oxidative stress. Redox Biol. 2024 May;71:103090.
ULK-101是一种选择性的ULK1（ IC50=1.6nM）抑制剂，还可抑制 ULK2（ IC50=30nM）的活性。ULK-101通过抑制自噬诱导和自噬流来阻断细胞自噬过程[1-2]。ULK-101可用于自噬机制研究和癌症（特别是KRAS突变肺癌）的相关研究[3-4]。
在体外，ULK-101（5μM）预处理U2OS细胞2.5小时，随后以AZD8055（100nM）刺激，ULK-101可显著抑制DFCP1阳性斑点和ATG12阳性吞噬斑的形成；ULK-101（5μM）处理细胞3小时，并在最后1.5小时加入BafA1（100nM），可显著抑制LC3B阳性囊泡的积累[5]。ULK-101（10μM）预处理A549、H1299及Mv1Lu细胞24小时，随后以TGFβ1（250pM）刺激。ULK-101可显著抑制细胞表面TGFβ受体向早期内体、晚期内体及溶酶体的运输，同时降低TGFβ1诱导的Smad2/Smad3磷酸化、核转位、上皮-间质转化（EMT）标记物（N-钙黏蛋白、Slug、Snail）表达、应激纤维形成及细胞迁移[6]。
在体内，ULK-101（20mg/kg）每日腹腔注射处理屋尘螨（HDM）诱导的哮喘野生型（WT）小鼠，持续10天。ULK-101可显著抑制肺组织中ULK1/Atg9a信号通路的激活，并降低NLRP3炎症小体及其下游效应分子caspase-1和IL-1β的表达[7]。