Department of General Surgery, Peking University First Hospital, Peking University, Beijing, P.R. China.
Oncol Res. 2019 Jul 12;27(7):739-750. doi: 10.3727/096504018X15360541345000. Epub 2018 Sep 4.
The activated form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], regulates numerous cellular processes, including inhibition of cancer progression. IL-1β has been reported to facilitate cancer development, especially by inducing an epithelial-to-mesenchymal transition (EMT) in several malignant tumors. However, the underlying mechanism of 1,25(OH)2D3 and IL-1β in colorectal cancer (CRC) still remains largely unknown. To fill in this knowledge gap, we measured cell proliferation and invasion by CCK-8 and Transwell assays after stimulation with 1,25(OH)2D3 and IL-1β. E-cadherin and vimentin were chosen as markers of EMT measured by immunofluorescence, quantitative real-time PCR (qRT-PCR), and Western blot. The expression and function of the vitamin D receptor (VDR) was evaluated by Western blot and luciferase reporter assay. qRT-PCR and RNA-FISH were performed to detect the expression and location of lncTCF7 in vitro. The binding sites of VDR in the lncTCF7 promoter were confirmed by a chromatin immunoprecipitation assay. Based on the above experiments, we found that 1,25(OH)2D3 attenuates IL-1β-induced increased proliferation and invasion in colorectal cancer through enhancing VDR, which inhibits the expression of lncTCF7 by directly binding to its promoter region.
维生素 D3 的激活形式，1,25-二羟维生素 D3[1,25(OH)2D3]，调节许多细胞过程，包括抑制癌症进展。已有报道称白细胞介素 1β（IL-1β）有助于癌症的发展，特别是通过诱导几种恶性肿瘤的上皮-间充质转化（EMT）。然而，1,25(OH)2D3 和 IL-1β 在结直肠癌（CRC）中的潜在机制在很大程度上仍然未知。为了填补这一知识空白，我们通过 CCK-8 和 Transwell 测定法在 1,25(OH)2D3 和 IL-1β 刺激后测量细胞增殖和侵袭。通过免疫荧光、实时定量 PCR（qRT-PCR）和 Western blot 选择 E-钙黏蛋白和波形蛋白作为 EMT 的标志物进行测量。通过 Western blot 和荧光素酶报告基因测定评估维生素 D 受体（VDR）的表达和功能。体外进行 qRT-PCR 和 RNA-FISH 以检测 lncTCF7 的表达和位置。通过染色质免疫沉淀测定证实 VDR 在 lncTCF7 启动子中的结合位点。基于上述实验，我们发现 1,25(OH)2D3 通过增强 VDR 来减弱 IL-1β 诱导的结直肠癌细胞增殖和侵袭的增加，通过直接结合其启动子区域抑制 lncTCF7 的表达。
