Early detection of capecitabine-resistance could largely increase overall survival of colorectal cancer (CRC) patients. Previous studies suggested examination of immune cells in peripheral blood would help to predict efficacy of chemotherapy. We examined the immunological characteristics of peripheral blood in CRC patients with capecitabine treatment. We analyzed the relationships between the abnormal immune cell population in capecitabine-resistance patients and major clinical features. Furthermore, RNA sequencing, analyses of cell surface marker expression and the correlations with other major immune cell populations were performed using this population to explore the possible function of these cells. The expression level of CD16 on neutrophils was down-regulated in capecitabine-resistant CRC patients. Patients with CD16low/−neutrophils after capecitabine therapy had adverse clinical features. What’s important, the change of CD16 expression level on neutrophils appeared much earlier than CT scan. RNA sequencing revealed that CD16low/−neutrophils in capecitabine-resistant patients had lower expression level of neutrophil-related genes, compared to CD16+neutrophils in capecitabine-sensitive patients, suggesting this CD16low/−population might be immature neutrophils. Furthermore, the expression level of CD16 on neutrophils in patients with capecitabine treatment was positively correlated with the number of anti-tumor immune cell subsets, such as CD8+T cell, CD4+T cell, NK cell and monocyte. Our findings indicated that CD16 expression on neutrophils in peripheral blood was a good prognostic marker for predicting efficacy of capecitabine in CRC patients.

中文翻译：

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中性粒细胞上的 CD16 表达可预测卡培他滨对结直肠癌患者的治疗效果。

卡培他滨耐药的早期检测可以在很大程度上提高结直肠癌 (CRC) 患者的总体生存率。先前的研究表明，检查外周血中的免疫细胞将有助于预测化疗的疗效。我们检查了接受卡培他滨治疗的 CRC 患者外周血的免疫学特征。我们分析了卡培他滨耐药患者的异常免疫细胞群与主要临床特征之间的关系。此外，使用该群体进行 RNA 测序、细胞表面标志物表达分析以及与其他主要免疫细胞群体的相关性，以探索这些细胞的可能功能。在卡培他滨耐药的 CRC 患者中，中性粒细胞上 CD16 的表达水平下调。卡培他滨治疗后 CD16low/-中性粒细胞的患者具有不良的临床特征。重要的是，中性粒细胞上CD16表达水平的变化比CT扫描出现的时间要早​​得多。RNA测序显示，与卡培他滨敏感患者的CD16+中性粒细胞相比，卡培他滨耐药患者的CD16low/-中性粒细胞的中性粒细胞相关基因的表达水平较低，表明该CD16low/-中性粒细胞群可能是未成熟的中性粒细胞。此外，卡培他滨治疗患者中性粒细胞上CD16的表达水平与抗肿瘤免疫细胞亚群的数量呈正相关，如CD8+T细胞、CD4+T细胞、NK细胞和单核细胞。