Tumor 英 /'tju:mə(r)/ 美 /'tjʊmɚ/
释 义 n. 肿瘤；肿块；赘生物
例 句 To evaluate the role of lung lobectomy in the patients of tumor with lung metastases. 目的是探讨肺叶切除术在肺转移瘤治疗中的作用。
释 义 n. [生态] 微环境；[生态] 小环境
例 句 Such manipulations of the microenvironment could offer new directions for cancer treatment, he said. 他说，这种对微环境的操作可能为癌症治疗提供新方向，
作者： Monica Marzagalli
期刊：Semin. Cancer Biol.
CAFs are known to promote cancer cell proliferation and invasion, and other findings demonstrated that these cells can participate to the evolution of an immunosuppressive environment, both within the tumor bulk and in metastatic niches, through the release of immune-modulatory factors. It has been recently demonstrated that melanoma-derived extracellular vesicles can induce a pro-inflammatory signature in lung fibroblasts (upregulation of cytokines and chemokines, including IL-1α, IL-1β, CXCL10, CXCL1, CCL2, CCL3 and CCL5), thus enhancing the recruitment of myeloid-derived cells such as neutrophils. Moreover, pro-inflammatory pathways, eventually associated with BRAF mutations, can in turn induce the expression of PD-1 ligands and COX-2 on CAFs, contributing to the immune suppression. CAFs can favor immune escape through the secretion of MMPs and of Prostaglandin E2 (PGE 2 ), decreasing NK-mediated lysis of melanoma cells mediated by a decreased surface expression of the activating receptor NKp44. T cell functions can be also affected by CAFs: the secretion of cytokines (i.e., CXCL5) can induce the expression of PD-1 on cancer cells, and the CAF-mediated metabolic stress of CD8+ T cells limits their functions against tumor cells. The following section will highlight the mechanisms exploited by melanoma cells to communicate with cells of the tumor microenvironment in order to promote an immunosuppressive setting.