Abdel-Mohsen Mohamed A, Abo Deif Samar M, Abou-Shamaa Lobna A
Department of Applied Medical Chemistry, Medical Research Institute, Medical Research Institute, 165 El-Horreya Avenue, El-Hadara, 21561 Alexandria, Alexandria University, Egypt. Email:
Department of Immunology and Allergy, Medical Research Institute, 165 El-Horreya Avenue, El-Hadara, 21561 Alexandria, Alexandria University, Egypt.
Asian Pac J Cancer Prev. 2019 Aug 1;20(8):2267-2273. doi: 10.31557/APJCP.2019.20.8.2267.
Objective: The present study aimed to investigate the possible role of IL-6 and 1α,25-dihydroxyvitamin D3 (1,25D) signaling in epithelial-mesenchymal transition (EMT) and stemness in triple-negative breast cancer (TNBC) cell line. Methods: TNBC cell line, HCC 1806, was treated with IL-6 and 1,25D for three and six days. Also, the role of vitamin D receptor (VDR) was studied by transfection of TNBC cell line with VDR gene and transfection efficiency was assessed using Human VDR enzyme-linked immunosorbent assay (ELISA). Changes in E-cadherin gene expression were analyzed by quantitative real-time PCR (qRT-PCR). Also, changes in CD44+ cells were analyzed by flow cytometry. Finally, morphological changes were investigated by light microscopy after 6 days. Results: Treatment of HCC1806 cells with IL-6 has no significant effect either on E-cadherin gene expression or CD44+ cells, (p > 0.05). However, E-cadherin gene expression was significantly up-regulated after treatment with 1,25D for 6 days, (p < 0.05). Also, CD44+ cells were significantly reduced after treatment with 1,25D either for 3 or 6 days, (p < 0.05). Transfection of TNBC cell line with VDR gene significantly up-regulated VDR protein expression, (p < 0.05). In addition, overexpression of VDR in TNBC cells and treatment with 1,25D significantly up-regulated E-cadherin gene expression, (p < 0.05) and reduced CD44+ cells, (p < 0.05). Moreover, transfection with VDR and treatment with a combination of 1,25D and IL-6 significantly down-regulated E-cadherin gene expression and increased CD44+ cells compared with transfected cells with VDR treated with 1,25D alone, (p < 0.05). No significant morphological changes were observed in treated cells, 6 days post-treatment. Conclusion: The presence of IL-6 in the breast tumor microenvironment may impair the activity of vitamin D3 signaling, limiting its anti-tumor effects in TNBC.
本研究旨在探讨白细胞介素-6（IL-6）和1α,25-二羟基维生素D3（1,25D）信号通路在三阴性乳腺癌（TNBC）细胞系上皮-间质转化（EMT）和干性中的可能作用。方法：用IL-6和1,25D处理TNBC细胞系HCC 1806，处理时间分别为3天和6天。此外，通过将VDR基因转染到TNBC细胞系中来研究维生素D受体（VDR）的作用，并使用人VDR酶联免疫吸附测定（ELISA）评估转染效率。通过定量实时聚合酶链反应（qRT-PCR）分析E-钙黏蛋白基因表达的变化。同时，通过流式细胞术分析CD44+细胞的变化。最后，在6天后通过光学显微镜观察形态学变化。结果：用IL-6处理HCC1806细胞对E-钙黏蛋白基因表达或CD44+细胞均无显著影响（p>0.05）。然而，用1,25D处理6天后，E-钙黏蛋白基因表达显著上调（p<0.05）。此外，用1,25D处理3天或6天后，CD44+细胞显著减少（p<0.05）。将VDR基因转染到TNBC细胞系中可显著上调VDR蛋白表达（p<0.05）。此外，TNBC细胞中VDR的过表达以及用1,25D处理可显著上调E-钙黏蛋白基因表达（p<0.05）并减少CD44+细胞（p<0.05）。此外，与仅用1,25D处理的VDR转染细胞相比，用VDR转染并用1,25D和IL-6联合处理可显著下调E-钙黏蛋白基因表达并增加CD44+细胞（p<0.05）。处理后6天，在处理的细胞中未观察到显著的形态学变化。结论：乳腺肿瘤微环境中IL-6的存在可能损害维生素D3信号通路的活性，限制其在TNBC中的抗肿瘤作用。
