During cancer evolution, tumor cells attract and dynamically interact with monocytes/macrophages. To find biomarkers of disease progression in human melanoma, we used unbiased RNA sequencing and secretome analyses of tumor–macrophage co-cultures. Pathway analysis of genes differentially modulated in human macrophages exposed to melanoma cells revealed a general upregulation of inflammatory hallmark gene sets, particularly chemokines. A selective group of chemokines, including CCL8, CCL15, and CCL20, was actively secreted upon melanoma–macrophage co-culture. Because we previously described the role of CCL20 in melanoma, we focused our study on CCL8 and CCL15 and confirmed that in vitro both chemokines contributed to melanoma survival, proliferation, and 3D invasion through CCR1 signaling. In vivo, both chemokines enhanced primary tumor growth, spontaneous lung metastasis, and circulating tumor cell survival and lung colonization in mouse xenograft models. Finally, we explored the clinical significance of CCL8 and CCL15 expression in human skin melanoma, screening a collection of 67 primary melanoma samples, using multicolor fluorescence and quantitative image analysis of chemokine–chemokine receptor content at the single-cell level. Primary skin melanomas displayed high CCR1 expression, but there was no difference in its level of expression between metastatic and nonmetastatic cases. By contrast, comparative analysis of these two clinically divergent groups showed a highly significant difference in the cancer cell content of CCL8 (p = 0.025) and CCL15 (p < 0.0001). Kaplan–Meier curves showed that a high content of CCL8 or CCL15 in cancer cells correlated with shorter disease-free and overall survival (log-rank test, p < 0.001). Our results highlight the role of CCL8 and CCL15, which are highly induced by melanoma–macrophage interactions in biologically aggressive primary melanomas and could be clinically applicable biomarkers for patient profiling. © 2024 The Pathological Society of Great Britain and Ireland.

中文翻译：

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黑色素瘤-巨噬细胞串扰的趋化因子分析将 CCL8 和 CCL15 确定为皮肤黑色素瘤的预后因素

在癌症进化过程中，肿瘤细胞吸引单核细胞/巨噬细胞并与其动态相互作用。为了寻找人类黑色素瘤疾病进展的生物标志物，我们使用了肿瘤-巨噬细胞共培养物的无偏 RNA 测序和分泌组分析。对暴露于黑色素瘤细胞的人类巨噬细胞中差异调节的基因进行的通路分析揭示了炎症标志基因组的普遍上调，特别是趋化因子。黑色素瘤-巨噬细胞共培养时，选择性地分泌一组趋化因子，包括 CCL8、CCL15 和 CCL20。因为我们之前描述了 CCL20 在黑色素瘤中的作用，所以我们将研究重点放在 CCL8 和 CCL15 上，并在体外证实这两种趋化因子通过 CCR1 信号传导促进黑色素瘤存活、增殖和 3D 侵袭。在体内，两种趋化因子都能增强小鼠异种移植模型中的原发性肿瘤生长、自发性肺转移、循环肿瘤细胞存活和肺定植。最后，我们通过多色荧光和单细胞水平趋化因子-趋化因子受体含量的定量图像分析，筛选了 67 个原发性黑色素瘤样本，探讨了 CCL8 和 CCL15 表达在人类皮肤黑色素瘤中的临床意义。原发性皮肤黑色素瘤表现出高CCR1表达，但其表达水平在转移性和非转移性病例之间没有差异。相比之下，这两个临床上不同组的比较分析显示，CCL8 ( p  = 0.025) 和 CCL15 ( p < 0.0001)的癌细胞含量存在高度显着差异 。Kaplan-Meier 曲线显示，癌细胞中高含量的 CCL8 或 CCL15 与较短的无病生存期和总生存期相关（对数秩检验，p  < 0.001）。我们的结果强调了 CCL8 和 CCL15 的作用，它们在生物侵袭性原发性黑色素瘤中由黑色素瘤-巨噬细胞相互作用高度诱导，可以作为临床上适用的患者分析生物标志物。© 2024 大不列颠及爱尔兰病理学会。