Background

Use of exosomes as biomarkers in non-small cell lung cancer (NSCLC) is an intriguing approach in the liquid-biopsy era. Exosomes are nano-sized vesicles with membrane-bound proteins that reflect their originating cell. Prognostic biomarkers are needed to improve patient selection for optimal treatment. We here evaluate exosomes by protein phenotyping as a prognostic biomarker in NSCLC.

Methods

Exosomes from plasma of 276 NSCLC patients were phenotyped using the Extracellular Vesicle Array; 49 antibodies captured the proteins on the exosomes, and a cocktail of biotin-conjugated antibodies binding the general exosome markers CD9, CD81 and CD63 was used to visualise the captured exosomes. For each individual membrane-bound protein, results were analysed based on presence, in a concentration-dependent manner, and correlated to overall survival (OS).

Results

The 49 proteins attached to the exosomal membrane were evaluated. NY-ESO-1, EGFR, PLAP, EpCam and Alix had a significant concentration-dependent impact on inferior OS. Due to multiple testing, NY-ESO-1 was the only marker that maintained a significant impact on inferior survival (hazard rate (HR) 1.78 95% (1.78–2.44); p = 0.0001) after Bonferroni correction. Results were adjusted for clinico-pathological characteristics, stage, histology, age, sex and performance status.

Conclusion

We illustrate the promising aspects associated with the use of exosomal membrane-bound proteins as a biomarker and demonstrate that they are a strong prognostic biomarker in NSCLC.

中文翻译：

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外泌体蛋白作为非小细胞肺癌的预后生物标志物。

背景

在非小细胞肺癌（NSCLC）中使用外泌体作为生物标志物在液体活检时代是一种引人入胜的方法。外泌体是具有膜结合蛋白的纳米大小的囊泡，可反映其原始细胞。需要预后生物标志物以改善患者选择以进行最佳治疗。我们在这里通过蛋白质表型评估外泌体作为NSCLC的预后生物标志物。

方法

使用细胞外囊泡阵列对276例NSCLC患者血浆中的外泌体进行了表型分析。49种抗体捕获了外泌体上的蛋白质，结合了一般外泌体标记CD9，CD81和CD63的生物素共轭抗体的混合物可用于可视化捕获的外泌体。对于每种单独的膜结合蛋白，均根据其存在以浓度依赖的方式分析结果，并将其与总生存期（OS）相关联。

结果

评估了附着在外体膜上的49种蛋白质。NY-ESO-1，EGFR，PLAP，EpCam和Alix对次要OS有明显的浓度依赖性影响。由于进行了多次测试，在Bonferroni校正后，NY-ESO-1是唯一对存活率低下具有重大影响（危险率（HR）1.78 95％（1.78–2.44）； p = 0.0001）的唯一标志物。根据临床病理特征，阶段，组织学，年龄，性别和表现状态对结果进行了调整。

结论

我们阐明了与使用外泌体膜结合蛋白作为生物标志物相关的有希望的方面，并证明它们是非小细胞肺癌的强预后生物标志物。