In the tumor microenvironment, various immune and stromal cells, such as fibroblasts and vascular endothelial cells, contribute to tumor growth and progression by interacting with cancer cells. Tumor-associated macrophages (TAMs) have attracted attention as major players in the tumor microenvironment. The origin of TAMs is believed to be the infiltration of monocytes derived from bone marrow progenitor cells into tumor tissues and their differentiation into macrophages, whereas tissue-resident macrophages derived from yolk sacs have recently been reported. TAMs infiltrating tumor tissues act in a tumor-promoting manner through immunosuppression, angiogenesis, and the promotion of cancer cell invasion. Reflecting the nature of TAMs, increased TAM invasion and TAM-specific gene expression in tumor tissues may be the new biomarkers for cancer. Moreover, new therapeutic strategies targeting TAMs, such as transformation into immunostimulatory macrophages, suppression of TAM infiltration, and promotion of phagocytosis, are being investigated, and many clinical trials are underway. As the origin and function of TAMs are further elucidated, TAM-targeted therapy is expected to become a new option for the immunotherapy of various cancers, including oral cancers.
在肿瘤微环境中，多种免疫细胞和基质细胞（如成纤维细胞和血管内皮细胞）通过与癌细胞相互作用，促进肿瘤的生长和进展。肿瘤相关巨噬细胞（TAMs）作为肿瘤微环境中的主要参与者备受关注。传统观点认为TAMs来源于骨髓祖细胞分化的单核细胞浸润至肿瘤组织并分化为巨噬细胞，而近期研究报道组织驻留型巨噬细胞亦可来源于卵黄囊。浸润至肿瘤组织的TAMs通过免疫抑制、促进血管生成及癌细胞侵袭等方式发挥促肿瘤作用。基于TAMs的特性，肿瘤组织中TAMs浸润增加及其特异性基因表达可能成为新型癌症生物标志物。目前针对TAMs的新型治疗策略正在探索中，包括将其转化为免疫刺激型巨噬细胞、抑制TAMs浸润以及促进吞噬作用等，多项临床试验正在进行。随着对TAMs起源和功能的深入研究，靶向TAMs的治疗有望成为包括口腔癌在内的多种癌症免疫治疗的新选择。
Refining the Role of Tumor-Associated Macrophages in Oral Squamous Cell Carcinoma
肿瘤(癌症)患者之家