背景:激活的Cdc42相关激酶1(ACK1)是一种有前途的癌症药物靶标,但其抑制剂仅在临床试验中显示出中等效果。本研究旨在探讨ACK1抑制剂的潜在作用机制,提高其抗肿瘤效果。
方法:进行RNA-seq以确定ACK的下游途径。使用LassoCox回归分析,我们在来自癌症基因组图谱(TCGA)项目的肺腺癌(LUAD)患者中构建了ACK1相关自噬基因的风险特征.在LUAD中评估了签名在预测肿瘤免疫环境以及对免疫疗法和化学疗法的反应中的性能。CCK8,mRFP-GFP-LC3测定,westernblot,菌落形成,伤口愈合,和transwell迁移试验进行评估ACK1抑制剂对肺癌细胞的影响。皮下NSCLC异种移植模型用于体内研究。
结果:RNA-seq揭示了ACK1在自噬中的调节作用。此外,风险特征将LUAD患者分为预后显著不同的低危组和高危组.两组在28个免疫细胞亚群上表现出不同的肿瘤免疫环境。低危人群的免疫评分较高,CTLA4高表达水平,高免疫表型,和低DNA错配修复能力,表明对免疫疗法有更好的反应。该特征还预测了对常用化疗和靶向药物的敏感性。体外,ACK1抑制剂(AIM-100和达沙替尼)似乎触发适应性自噬样反应以保护肺癌细胞免于凋亡并激活AMPK/mTOR信号通路,部分解释了其适度的抗肿瘤功效。然而,用氯喹/BafilamycineA1阻断溶酶体降解或用化合物C/shPRKAA1抑制AMPK信号增强了ACK1抑制剂对肺癌细胞的细胞毒性作用。还使用小鼠异种移植模型验证了联合疗法的功效。
结论:来自ACK1相关自噬基因的特征强有力地预测了LUAD的生存和药物敏感性。溶酶体降解抑制改善了ACK1抑制剂的治疗效果,提示自噬在逃避治疗中的潜在作用。
Activated Cdc42-associated kinase 1 (ACK1) is a promising druggable target for cancer, but its inhibitors only showed moderate effects in clinical trials. The study aimed to investigate the underlying mechanisms and improve the antitumor efficacy of ACK1 inhibitors.
RNA-seq was performed to determine the downstream pathways of ACK. Using Lasso Cox regression analysis, we built a risk signature with ACK1-related autophagy genes in the lung adenocarcinoma (LUAD) patients from The Cancer Genome Atlas (TCGA) project. The performance of the signature in predicting the tumor immune environment and response to immunotherapy and chemotherapy were assessed in LUAD. CCK8, mRFP-GFP-LC3 assay, western blot, colony formation, wound healing, and transwell migration assays were conducted to evaluate the effects of the ACK1 inhibitor on lung cancer cells. A subcutaneous NSCLC xenograft model was used for in vivo study.
RNA-seq revealed the regulatory role of ACK1 in autophagy. Furthermore, the risk signature separated LUAD patients into low- and high-risk groups with significantly different prognoses. The two groups displayed different tumor immune environments regarding 28 immune cell subsets. The low-risk groups showed high immune scores, high CTLA4 expression levels, high immunophenoscore, and low DNA mismatch repair capacity, suggesting a better response to immunotherapy. This signature also predicted sensitivity to commonly used chemotherapy and targeted drugs. In vitro, the ACK1 inhibitors (AIM-100 and Dasatinib) appeared to trigger adaptive autophagy-like response to protect lung cancer cells from apoptosis and activated the AMPK/mTOR signaling pathway, partially explaining its moderate antitumor efficacy. However, blocking lysosomal degradation with chloroquine/Bafilamycine A1 or inhibiting AMPK signaling with compound C/shPRKAA1 enhanced the ACK1 inhibitor\'s cytotoxic effects on lung cancer cells. The efficacy of the combined therapy was also verified using a mouse xenograft model.
The resulting signature from ACK1-related autophagy genes robustly predicted survival and drug sensitivity in LUAD. The lysosomal degradation inhibition improved the therapeutic effects of the ACK1 inhibitor, suggesting a potential role for autophagy in therapy evasion.