Department of Pharmacology, Faculty of Pharmacy, University of Granada, 18012 Granada, Spain.
Research Unit, Instituto de Investigación Biosanitaria de Granada (ibs.GRANADA), 18016 Granada, Spain.
Int J Mol Sci. 2024 Jun 1;25(11):6098. doi: 10.3390/ijms25116098.
Eosinophils are myeloid effector cells whose main homing is the gastrointestinal tract. There, they take part in type I and type II immune responses. They also contribute to other non-immunological homeostatic functions like mucus production, tissue regeneration, and angiogenesis. In colorectal cancer (CRC), eosinophils locate in the center of the tumor and in the front of invasion and play an anti-tumoral role. They directly kill tumor cells by releasing cytotoxic compounds and eosinophil extracellular traps or indirectly by activating other immune cells via cytokines. As CRC progresses, the number of infiltrating eosinophils decreases. Although this phenomenon is not fully understood, it is known that some changes in the microenvironmental milieu and microbiome can affect eosinophil infiltration. Importantly, a high number of intratumoral eosinophils is a favorable prognostic factor independent from the tumor stage. Moreover, after immunotherapy, responding patients usually display eosinophilia, so eosinophils could be a good biomarker candidate to monitor treatment outcomes. Finally, even though eosinophils seem to play an interesting anti-tumoral role in CRC, much more research is needed to fully understand their interactions in the CRC microenvironment. This review explores the multifaceted roles of eosinophils in colorectal cancer, highlighting their anti-tumoral effects, prognostic significance, and potential as a biomarker for treatment outcomes.
嗜酸性粒细胞是髓系效应细胞，其主要归巢部位是胃肠道。在胃肠道中，它们参与 I 型和 II 型免疫反应。它们还参与其他非免疫性稳态功能，如黏液产生、组织再生和血管生成。在结直肠癌（CRC）中，嗜酸性粒细胞位于肿瘤中心和侵袭前沿，发挥抗肿瘤作用。它们通过释放细胞毒性化合物和嗜酸性粒细胞细胞外陷阱直接杀死肿瘤细胞，或通过细胞因子间接激活其他免疫细胞。随着 CRC 的进展，浸润的嗜酸性粒细胞数量减少。尽管这种现象尚未完全阐明，但已知微环境和微生物组的某些变化会影响嗜酸性粒细胞的浸润。重要的是，肿瘤内大量嗜酸性粒细胞是独立于肿瘤分期的有利预后因素。此外，在免疫治疗后，有反应的患者通常会出现嗜酸性粒细胞增多，因此嗜酸性粒细胞可能是监测治疗效果的良好生物标志物候选物。最后，尽管嗜酸性粒细胞在 CRC 中似乎发挥着有趣的抗肿瘤作用，但仍需要更多的研究来充分了解它们在 CRC 微环境中的相互作用。本文综述了嗜酸性粒细胞在结直肠癌中的多方面作用，强调了它们的抗肿瘤作用、预后意义以及作为治疗效果生物标志物的潜力。
