Ke Zi-Hao, Chen Ying, Yu Tao, Zhang Qi, Xiang Yan, Lu Kai-Hua
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Ningbo University, Ningbo, Zhejiang, China.
Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
Cancer Med. 2024 Dec;13(23):e70486. doi: 10.1002/cam4.70486.
Immune biomarkers for non-small-cell lung cancer (NSCLC) are programmed death ligand 1 (PD-L1) and tumor mutational burden (TMB). However, they cannot accurately predict the effectiveness of immunotherapy. Identifying appropriate biomarkers that can differentiate between beneficiary groups is imperative.
We identified lipoprotein receptor-related protein 1B (LRP1B) mutation as a potential biomarker for immunotherapy by analyzing clinical data, combined with bioinformatics analysis. The effects of LRP1B on ferroptosis were assessed using qRT-PCR, Western blotting, CCK-8 assay, and flow cytometry. The potential mechanism underlying the regulation of ferroptosis by LRP1B was elucidated using qRT-PCR, Western blotting, ChIP, and dual-luciferase reporter gene assays.
Through the collection and analysis of clinical data, we had established that LRP1B mutations are closely associated with immunotherapy. Bioinformatics analysis revealed significant differences in the expression levels of PD-L1 and TMB between patients with LRP1B mutation and wild-type patients in lung adenocarcinoma (LUAD). Furthermore, we observed that patients with LRP1B mutation in LUAD had significantly higher levels of tumor-infiltrating lymphocytes (TILs) than wild-type patients. In addition, we found that patients with LRP1B mutation in LUAD had significantly prolonged progression-free survival (PFS) compared to wild-type patients. However, the differences of PD-L1 expression, TILs, and PFS were not observed in patients with LRP1B mutation in lung squamous cell carcinoma (LUSC). These findings provided strong evidence that LRP1B mutation was a potential biomarker for immunotherapy in LUAD. Moreover, our in vivo experiments indicated that knockdown of LRP1B enhanced the efficacy of mPD-1, and mechanistic studies revealed that LRP1B regulated the sensitivity of cells to ferroptosis by modulating the expression of SLC7A11 through altering the phosphorylation level of STAT3. Further analysis revealed that LRP1B knockdown promoted immunotherapy in vivo.
Our results confirmed that LRP1B affected the efficacy of immunotherapy by modulating the sensitivity of NSCLC cells to ferroptosis. LRP1B mutations represent a highly promising immunotherapeutic biomarker for NSCLC.
非小细胞肺癌（NSCLC）的免疫生物标志物是程序性死亡配体1（PD-L1）和肿瘤突变负荷（TMB）。然而，它们无法准确预测免疫治疗的疗效。识别能够区分受益群体的合适生物标志物势在必行。
我们通过分析临床数据并结合生物信息学分析，将脂蛋白受体相关蛋白1B（LRP1B）突变鉴定为免疫治疗的潜在生物标志物。使用qRT-PCR、蛋白质印迹法、CCK-8测定法和流式细胞术评估LRP1B对铁死亡的影响。使用qRT-PCR、蛋白质印迹法、染色质免疫沉淀（ChIP）和双荧光素酶报告基因测定法阐明LRP1B调节铁死亡的潜在机制。
通过临床数据的收集和分析，我们确定LRP1B突变与免疫治疗密切相关。生物信息学分析显示，肺腺癌（LUAD）中LRP1B突变患者与野生型患者之间PD-L1和TMB的表达水平存在显著差异。此外，我们观察到LUAD中LRP1B突变患者的肿瘤浸润淋巴细胞（TILs）水平明显高于野生型患者。此外，我们发现LUAD中LRP1B突变患者的无进展生存期（PFS）明显长于野生型患者。然而，肺鳞状细胞癌（LUSC）中LRP1B突变患者未观察到PD-L1表达、TILs和PFS的差异。这些发现提供了强有力的证据，表明LRP1B突变是LUAD免疫治疗的潜在生物标志物。此外，我们的体内实验表明，敲低LRP1B可增强mPD-1的疗效，机制研究表明，LRP1B通过改变STAT3的磷酸化水平调节SLC7A11的表达，从而调节细胞对铁死亡的敏感性。进一步分析表明，敲低LRP1B可促进体内免疫治疗。
我们的结果证实，LRP1B通过调节NSCLC细胞对铁死亡的敏感性影响免疫治疗的疗效。LRP1B突变是NSCLC极具前景的免疫治疗生物标志物。
