Table_11_Immune Checkpoints OX40 and OX40L in Small-Cell Lung Cancer: Predict Prognosis and Modulate Immune Microenvironment.docx

BackgroundOX40 and OX40 ligand (OX40L), as essential immune checkpoint (IC) modulators, are highly correlated with cancer immunity regulation as well as tumor microenvironment (TME). Immunotherapy showed outstanding advantages in small-cell lung cancer (SCLC) therapy. However, functions and clinical significance of OX40 and OX40L in SCLC were not clear yet.
Materials and MethodsSCLC samples of 143 patients were collected for immunohistochemistry (IHC) or whole-exome sequencing (WES). We comprehensively explored the expression and mutation of OX40/OX40L in SCLC, and systematically linked OX40/OX40L with TME.
ResultsThe expression of OX40/OX40L on tumor cells and tumor-infiltrating lymphocytes (TILs) was found in the IHC cohort and verified in other cohorts with SCLC tissues and cell lines. The results showed co-expression patterns among OX40/OX40L, other ICs, and T-cell markers. The WES data suggested that OX40/OX40L mutation is rare in SCLC (<5%). Patients with positive OX40 protein expression on TILs showed substantially higher recurrence-free survival than those with negative expression (p=0.009). The external dataset also indicated that high OX40/OX40L expression was correlated with better prognosis [overall survival: OX40, p<0.001; OX40L, p=0.019]. Importantly, activation of immunity and high infiltration of CD4(+) and CD8(+) T cells were observed in the high OX40/OX40L expression group.
ConclusionsCollectively, this work highlighted the significance of OX40 and OX40L in prognosis and TME cell infiltration characterization of SCLC. Evaluating the OX40/OX40L-expression levels of individual patients with SCLC might contribute to guiding more precise therapy.

**背景** OX40与OX40配体（OX40L）作为关键免疫检查点（immune checkpoint, IC）调节分子，与癌症免疫调控及肿瘤微环境（tumor microenvironment, TME）密切相关。免疫治疗在小细胞肺癌（small-cell lung cancer, SCLC）治疗中展现出卓越优势，但OX40与OX40L在小细胞肺癌中的功能及临床意义至今尚未阐明。
**材料与方法** 本研究收集143例小细胞肺癌患者的样本，用于免疫组化（immunohistochemistry, IHC）检测或全外显子组测序（whole-exome sequencing, WES）。我们全面探究了小细胞肺癌中OX40/OX40L的表达与突变特征，并系统关联了OX40/OX40L与肿瘤微环境的关系。
**结果** 在免疫组化队列中检测到肿瘤细胞及肿瘤浸润淋巴细胞（tumor-infiltrating lymphocytes, TILs）表面的OX40/OX40L表达，并在其他包含小细胞肺癌组织及细胞系的队列中得到验证。结果显示，OX40/OX40L与其他免疫检查点分子及T细胞标志物存在共表达模式。全外显子组测序数据表明，OX40/OX40L在小细胞肺癌中突变率极低（<5%）。肿瘤浸润淋巴细胞中OX40蛋白阳性表达的患者，其无复发生存期显著长于阴性表达患者（p=0.009）。外部验证队列亦显示，高表达OX40/OX40L与更佳预后相关[总生存期：OX40，p<0.001；OX40L，p=0.019]。值得注意的是，OX40/OX40L高表达组呈现免疫激活状态，且CD4+与CD8+ T细胞浸润程度更高。
**结论** 综上，本研究明确了OX40与OX40L在小细胞肺癌预后评估及肿瘤微环境细胞浸润特征表征中的重要意义。对小细胞肺癌患者的OX40/OX40L表达水平进行检测，或有助于指导更精准的个体化治疗。