Laboratory of Internal Medicine, The First Affiliated Hospital of Wenzhou Medical College, 2 FuXue Road, Wenzhou 325000, China.
J Exp Clin Cancer Res. 2012 Mar 27;31(1):27. doi: 10.1186/1756-9966-31-27.
Pure curcumin has been reported to down-regulate the expression of WT1 in leukemic cells. However, the molecular mechanism underlying the down-regulation of WT1 by curcumin is not completely delineated. The purpose of this present study is to identify a new miRNA-mediated mechanism which plays an important role in the anti-proliferation effects of curcumin in leukemic cells.
K562 and HL-60 cells were treated with different concentrations of curcumin for 24 and 48 hours, the level of miR-15a/16-1 and WT1 were detected by qRT-PCR and Western blotting. WT1 expression and cell proliferation were detected by Western blotting and CCK-8, after curcumin treated-K562 and HL-60 cells were transfected with anti-miR-15a/16-1 oligonucleotides.
We found that pure curcumin upregulated the expression of miR-15a/16-1 and downregulated the expression of WT1 in leukemic cells and primary acute myeloid leukemia (AML) cells. Overexpression of miR-15a/16-1 deduced the protein level of WT1 in leukemic cells, but downregulation of WT1 by siRNA-WT1 could not increase the expression of miR-15a/16-1 in leukemic cells. These results reveal that curcumin induced-upregulation of miR-15a/16-1 is an early event upstream to downregulation of WT1. Furthermore, anti-miR-15a/16-1 oligonucleotides (AMO) partly reversed the downregulation of WT1 induced by pure curcumin in leukemic cells and AMO promoted the growth of curcumin treated-K562 and HL-60 cells.
Thus, these data suggest for the first time that pure curcumin downregulated the expression of WT1 partly by upregulating the expression of miR-15a/16-1 in leukemic cells. miR-15a/16-1 mediated WT1 downregulation plays an important role in the anti-proliferation effect of curcumin in leukemic cells.
已有报道称，纯姜黄素可下调白血病细胞中 WT1 的表达。然而，姜黄素下调 WT1 的分子机制尚未完全阐明。本研究旨在确定一种新的 miRNA 介导的机制，该机制在姜黄素抑制白血病细胞增殖中发挥重要作用。
用不同浓度的姜黄素处理 K562 和 HL-60 细胞 24 和 48 小时，用 qRT-PCR 和 Western blot 检测 miR-15a/16-1 和 WT1 的水平。用 Western blot 和 CCK-8 检测姜黄素处理后的 K562 和 HL-60 细胞的 WT1 表达和细胞增殖，然后用抗 miR-15a/16-1 寡核苷酸转染。
我们发现纯姜黄素可上调白血病细胞和原发性急性髓系白血病（AML）细胞中 miR-15a/16-1 的表达，并下调 WT1 的表达。miR-15a/16-1 的过表达降低了白血病细胞中 WT1 的蛋白水平，但 siRNA-WT1 下调 WT1 不能增加白血病细胞中 miR-15a/16-1 的表达。这些结果表明，姜黄素诱导的 miR-15a/16-1 上调是下调 WT1 的早期事件，在上游起作用。此外，抗 miR-15a/16-1 寡核苷酸（AMO）部分逆转了纯姜黄素诱导的白血病细胞中 WT1 的下调，AMO 促进了姜黄素处理后的 K562 和 HL-60 细胞的生长。
因此，这些数据首次表明，纯姜黄素通过上调白血病细胞中 miR-15a/16-1 的表达，部分下调 WT1 的表达。miR-15a/16-1 介导的 WT1 下调在姜黄素抑制白血病细胞增殖中发挥重要作用。
