PO.ET09.10 · 实验与分子治疗
靶向多价受体酪氨酸激酶以增强抗PD-1免疫治疗在胃癌中的疗效
Targeting multivalent receptor tyrosine kinases to enhance the efficacy of anti-PD-1 immunotherapy in gastric cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：胃癌（GC）是全球第五大常见癌症和第五大癌症相关死亡原因。GC对免疫检查点阻断（ICB）治疗的应答相对较差，近三分之二的患者因肿瘤维持免疫抑制性微环境并对免疫治疗产生耐药的能力而无应答。此前，我们证明多靶点受体酪氨酸激酶（RTK）抑制剂多韦替尼（dovitinib）可抑制肿瘤生长，并通过促进CD8+ T细胞募集进入免疫抑制型小鼠胃癌来重塑肿瘤微环境（TME）。本研究旨在评估多韦替尼是否能增强PD-1阻断的治疗效果。
方法：采用ATP-GLO在体外测定细胞活力。利用含两种不同小鼠GC细胞系的同基因小鼠胃肿瘤模型来评估多韦替尼与抗PD-1治疗的协同效应。采用免疫荧光（IF）和流式细胞术进行免疫表型分析。
结果：多韦替尼与PD-1阻断的联合显著优于任一单药治疗，在两种模型中均使肿瘤生长减少、动物生存延长（p<0.01）。IF分析显示，虽然单用多韦替尼增加了肿瘤核心区CD8+ T细胞浸润，但联合治疗相比其他组进一步增强了细胞毒性T细胞（Perforin+ CD8+）的浸润（p<0.01）。此外，多参数流式细胞术结合FlowSOM聚类分析显示，具有更高活化（CD69+）且耗竭标志物（PD-1、CTLA-4）表达更低或缺失的CD4+和CD8+ T细胞簇有所增加。相比之下，单用多韦替尼与更耗竭的T细胞表型相关。值得注意的是，只有联合治疗增强了细胞毒性T细胞的肿瘤杀伤能力。
结论：我们的发现表明，多韦替尼与PD-1阻断的联合显著优于任一单药治疗，因为这两种疗法协同重塑TME，超越了它们各自的直接细胞毒性效应。这种协同作用是通过增加活化的肿瘤浸润淋巴细胞（TIL）浸润，并减少单药治疗中通常所见的耗竭表型而实现的。本研究支持将多靶点RTK抑制剂与免疫治疗联合作为胃癌有效治疗策略的理论依据。
查看英文原文 English abstract
Background: Gastric cancer (GC) is the fifth most common cancer and the fifth leading cause of cancer-related deaths globally. The response to immune checkpoint blockade (ICB) therapy in GC is relatively poor with almost two thirds of the patients not responding due to the tumor's ability to maintain an immunosuppressive microenvironment and develop resistance to immunotherapy. Previously, we demonstrated that dovitinib, a multi-target receptor tyrosine kinases (RTKs) inhibitor, suppresses tumor growth and remodels the tumor microenvironment (TME) by facilitating the recruitment of CD8+ T cells into immune-suppressive types of mouse gastric cancer. This study aimed to assess whether dovitinib enhances the therapeutic effectiveness of PD-1 blockade.
Methods: ATP-GLO to measure cell viability in vitro. A syngeneic murine gastric tumor model with two distinct mouse GC cell lines was utilized to assess the synergistic effects of dovitinib and anti-PD-1 treatment. IF and flow cytometry to immunophenotyping.
Results: The combination of dovitinib and PD-1 blockade was significantly more effective than either treatment alone, leading to reduced tumor growth and increased animal survival in both models (p<0.01). IF analysis revealed that while dovitinib alone increased CD8+ T cell infiltration in the tumor core, the combination treatment further enhanced the infiltration of cytotoxic T cells (Perforin+ CD8+) compared to the other groups (p<0.01). Furthermore, multiparametric flow cytometry combined with FlowSOM clustering analysis showed an increase in CD4+ and CD8+ T cell clusters with higher activation (CD69+) and lower or absent expression of exhaustion markers (PD-1, CTLA-4). In contrast, dovitinib alone was associated with a more exhausted T cell phenotype. Notably, only the combination treatment increased the tumor killing capacity of the cytotoxic T cells.
Conclusion: Our findings demonstrate that the combination of dovitinib and PD-1 blockade is significantly more effective than either treatment alone, as the two therapies synergistically remodel the TME beyond their direct cytotoxic effects. This synergy is achieved by increasing the infiltration of activated tumor-infiltrating lymphocytes (TILs) and reducing the exhaustion phenotype typically seen with monotherapy. This study supports the rationale for combining multi-target RTKs inhibitors with immunotherapies as an effective therapeutic strategy for gastric cancer.
利益披露 Disclosure
M. Genoula, None.