PO.CL01.18 · 临床研究
循环早期髓源性抑制细胞作为肺癌中肿瘤驱动的髓系生成及疾病进展的指标
Circulating early myeloid-derived suppressor cells as indicators of tumor-driven myelopoiesis and disease progression in lung cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：肺癌（LC）仍是全球癌症相关死亡的首要原因。尽管治疗取得了重大进展，肺癌患者的预后仍然不佳。越来越多的证据表明，肿瘤驱动的造血重塑和全身性炎症积极维持着免疫抑制和疾病进展。未成熟髓系群体，尤其是髓源性抑制细胞（MDSCs）的扩增，是肿瘤诱导的应急性髓系生成的一个标志。然而，循环MDSC亚群的组成和发育层级仍不明确。在此，我们鉴定出一个此前未被认识的循环早期MDSCs（eMDSCs）亚群，它反映了肿瘤驱动的髓系生成激活和肺癌进展。
方法：在一个前瞻性发现队列中，纳入了肺癌患者（n=63）和无癌症的重度吸烟者（HS，n=52），从新鲜外周血中对循环髓系亚群进行了表征。多参数流式细胞术能够对外周血单个核细胞（PBMCs）进行全面分析。eMDSCs被定义为Lineage⁻HLA-DR⁻区室内的CD11b⁺CD33⁺CD15⁻细胞。一个回顾性验证队列（LC，n=58；HS，n=58），在性别、年龄和吸烟状态上进行了匹配，证实了这些发现，并探究了其与肿瘤分期和COPD相关炎症的关联。从代表性LC和HS样本中经FACS分选的eMDSCs接受了针对PD-L1和ARG1表达的qPCR分析。采用Kruskal-Wallis（KW）检验和Wilcoxon（WILC）检验进行统计分析。
结果：在发现队列和验证队列中（总计n=231），肺癌患者表现出循环CD11b⁺髓系群体的富集增加（WILC检验p值：无统计学意义p=0.052，p=0.001），尤其是Lin⁻HLA-DR⁻CD33⁺CD11b⁺MDSCs（WILC检验p值：p<0.0001，p=0.009）。在该群体中，鉴定出一个独特的CD15⁻未成熟早期MDSCs亚群（WILC检验p值：p<0.0001，p=0.014），并发现其在II-III期肺癌中特异性增加，但在IV期未进一步扩增（KW检验p值：p=0.015）。eMDSC水平与COPD相关炎症之间未发现关联，支持其为肿瘤特异性扩增。此外，NK细胞频率与eMDSCs平行增加，提示存在功能性相互作用，因为eMDSCs可能抑制NK活性（KW检验p值：p=0.002）。与此一致，qPCR分析显示，与HS相比，LC来源的eMDSCs中PD-L1和ARG1表达更高，表明其发生了免疫调节性极化。
结论：我们的发现将循环早期MDSCs鉴定为肺癌相关应急性髓系生成的一个标志。它们在II-III期疾病中的选择性扩增支持了它们作为循环生物标志物用于识别和监测肿瘤驱动的髓系生成激活及肺癌进展的潜力。
查看英文原文 English abstract
Background: Lung cancer (LC) remains the leading cause of cancer-related mortality worldwide. Despite major therapeutic advances, LC patients still experience poor prognosis. Increasing evidence indicates that tumor-driven hematopoietic remodeling and systemic inflammation actively sustain immune suppression and disease progression. The expansion of immature myeloid populations, particularly myeloid-derived suppressor cells (MDSCs), represents a hallmark of tumor-induced emergency myelopoiesis. However, the composition and developmental hierarchy of circulating MDSC subsets remain unclear. Here, we identify a previously unrecognized subset of circulating early MDSCs (eMDSCs) that mirrors tumor-driven myelopoietic activation and lung cancer progression.
Methods: In a prospective discovery cohort including LC patients (n=63) and heavy smokers without cancer (HS, n=52), circulating myeloid subsets were characterized from fresh peripheral blood. Multiparametric flow cytometry enabled comprehensive profiling of peripheral blood mononuclear cells (PBMCs). eMDSCs were defined as CD11b⁺CD33⁺CD15⁻ within the Lineage⁻HLA-DR⁻ compartment. A retrospective validation cohort (LC, n=58; HS, n=58), matched for sex, age, and smoking status, confirmed the findings and explored associations with tumor stage and COPD-related inflammation. FACS-sorted eMDSCs from representative LC and HS samples underwent qPCR analysis for PD-L1 and ARG1 expression. Statistical analyses were performed using the Kruskal-Wallis (KW) and Wilcoxon (WILC) tests.
Results: In both discovery and validation cohorts (total n=231), LC patients displayed an increased enrichment of circulating CD11b⁺ myeloid populations (WILC test p-value: non-significant p=0.052, p=0.001), particularly Lin⁻HLA-DR⁻CD33⁺CD11b⁺ MDSCs (WILC test p-value: p<0.0001, p=0.009). Within this population, a distinct immature subset of CD15⁻ early MDSCs was identified (WILC test p-value: p<0.0001, p=0.014) and found to be specifically increased in stage II-III LC, but not further expanded at stage IV (KW test p-value: p=0.015). No association emerged between eMDSC levels and COPD-related inflammation, supporting a tumor-specific expansion. Moreover, NK cell frequencies increased in parallel with eMDSCs, suggesting a functional interplay, as eMDSCs may suppress NK activity (KW test p-value: p=0.002). Consistently, qPCR analysis revealed higher PD-L1 and ARG1 expression in LC-derived eMDSCs compared with HS, indicating their immunoregulatory polarization.
Conclusion: Our findings identify circulating early MDSCs as a hallmark of lung cancer-associated emergency myelopoiesis. Their selective expansion in stage II-III disease supports their potential as circulating biomarkers to identify and monitor tumor-driven myelopoietic activation and lung cancer progression.
利益披露 Disclosure
A. Zanichelli, None..
M. Lecchi, None..
P. Verderio, None..
L. Rolli, None..
U. Pastorino, None..
G. Sozzi, None..
C. Chiodoni, None..
S. Sangaletti, None.