Department of Pharmaceutical and Pharmacological Sciences, University of Padova, L.go Meneghetti 2, 35131 Padova, Italy.
Chemistry and Health Faculty, Technical University of Machala, Ave. Panamericana Vía a Pasaje Km. 5 1/2, Machala 070101, Ecuador.
Nutrients. 2020 Jul 9;12(7):2040. doi: 10.3390/nu12072040.
Tumor-associated macrophages (TAMs), primarily the M2 phenotype, are involved in the progression and metastasis of colorectal cancer (CRC). Cuban brown propolis (Cp) and its main component Nemorosone (Nem) displays an antiproliferative effect on different cancer cells, including CRC cell lines. However, whether Cp and Nem could exploit its effect on CRC cells by targeting their relationship with TAMs remains to be elucidated. In this study, we differentiated the human monocytic THP-1 cells to M2 macrophages and confirmed this transition by immunofluorescence (IF) staining, qRT-PCR and zymography. An MTT assay was performed to determine the effect of Cp and Nem on the viability of CRC HT-29 cells co-cultured with M2 macrophages. Furthermore, the migration and invasion abilities of HT-29 cells were determined by Transwell assays and the expression levels of epithelial-mesenchymal transition (EMT) markers were analyzed by IF staining. We demonstrated that Cp and Nem reduced the viability of M2 macrophages and, accordingly, the activity of the MMP-9 metalloprotein. Moreover, we demonstrated that M2 macrophages produce soluble factors that positively regulate HT-29 cell growth, migration and invasion. These M2-mediated effects were counteracted by Cp and Nem treatments, which also played a role in regulating the expression of the EMT markers E-cadherin and vimentin. Taken together, our results indicate that Nem contained in Cp interferes in the crosstalk between CRC cells and TAMs, by targeting M2 macrophages.
肿瘤相关巨噬细胞（TAMs），主要是 M2 表型，参与结直肠癌（CRC）的进展和转移。古巴棕蜂胶（Cp）及其主要成分 Nemorosone（Nem）对不同的癌细胞，包括 CRC 细胞系，显示出抗增殖作用。然而，Cp 和 Nem 是否可以通过靶向它们与 TAMs 的关系来利用其对 CRC 细胞的作用仍有待阐明。在这项研究中，我们将人单核细胞 THP-1 细胞分化为 M2 巨噬细胞，并通过免疫荧光（IF）染色、qRT-PCR 和组织蛋白酶谱证实了这种转变。通过 MTT 测定法测定 Cp 和 Nem 对与 M2 巨噬细胞共培养的 CRC HT-29 细胞活力的影响。此外，通过 Transwell 测定法测定 HT-29 细胞的迁移和侵袭能力，并通过 IF 染色分析上皮-间充质转化（EMT）标志物的表达水平。我们表明 Cp 和 Nem 降低了 M2 巨噬细胞的活力，相应地降低了 MMP-9 金属蛋白酶的活性。此外，我们表明 M2 巨噬细胞产生可溶性因子，这些因子正向调节 HT-29 细胞的生长、迁移和侵袭。Cp 和 Nem 处理抵消了这些 M2 介导的效应，它们还在调节 EMT 标志物 E-钙粘蛋白和波形蛋白的表达方面发挥作用。总之，我们的结果表明，Cp 中包含的 Nem 通过靶向 M2 巨噬细胞干扰 CRC 细胞与 TAMs 之间的串扰。
