The 1st Department of Neurosurgery, The People's Hospital of Yinan, Yinan, Shandong, China.
Eur Rev Med Pharmacol Sci. 2017 Nov;21(22):5072-5080. doi: 10.26355/eurrev_201711_13821.
Gliomas are accompanied with high mortality owning to their invasive peculiarity and vulnerability to drug resistance. miR-21 is a vital oncogenic miRNA that regulates drug resistance of tumor cells. This study aims to elucidate the function of miR-21 in human glioma cells resistant to carmustine (BCNU) and to demonstrate the underlying molecular mechanism.
BCNU-sensitive cells (SWOZ2 cells) were transfected with miR-21 agomir and negative control, and BCNU-resistance cells (SWOZ2-BCNU cells) were transfected with miR-21 antagomir and negative control. The Real-time fluorescence quantitative PCR was used to detect and compare the levels of miR-21expression between SWOZ2-BCNU and SWOZ2 cells. The drug sensitivity of these cells to BCNU was determined by Cell Counting Kit-8 (CCK-8) assay. The protein expression of Spry2 was detected by Western blotting.
The expression level of miR-21 was remarkably higher in SWOZ2-BCNU cells than that in SWOZ2 cells. The half-maximal inhibitory concentration (IC50) of BCNU was obviously higher for SWOZ2-BCNU cells than that for SWOZ2 cells. Besides, we found that aberrant expression of miR-21 in SWOZ2-BCNU cells is responsible for glioma BCNU-resistance. Consistently, Spry2 protein levels were significantly reduced in SWOZ2-BCNU as well as in miR-21 agomir-transfected cells, inversely correlated to miR-21 expression. The results of si-Spry2 co-transfection suggested that the effect of miR-21 on glioma BCNU-resistance is mediated through Spry2.
miR-21 enhances the resistance of human glioma cells to BCNU by decreasing the expression of Spry2 protein. Thus, Spry2 may be a novel therapeutic target for treating glioma BCNU-resistance.
由于侵袭性和耐药性，神经胶质瘤的死亡率很高。miR-21 是一种重要的致癌 miRNA，可调节肿瘤细胞的耐药性。本研究旨在阐明 miR-21 在人神经胶质瘤细胞对卡莫司汀（BCNU）耐药中的作用，并揭示其潜在的分子机制。
用 miR-21 激动剂和阴性对照转染 BCNU 敏感细胞（SWOZ2 细胞），用 miR-21 拮抗剂和阴性对照转染 BCNU 耐药细胞（SWOZ2-BCNU 细胞）。采用实时荧光定量 PCR 检测并比较 SWOZ2-BCNU 细胞和 SWOZ2 细胞中 miR-21 表达水平。CCK-8 法检测这些细胞对 BCNU 的药物敏感性。Western blot 检测 Spry2 蛋白表达。
SWOZ2-BCNU 细胞中 miR-21 的表达水平明显高于 SWOZ2 细胞。SWOZ2-BCNU 细胞的 BCNU 半数抑制浓度（IC50）明显高于 SWOZ2 细胞。此外，我们发现 SWOZ2-BCNU 细胞中 miR-21 的异常表达导致神经胶质瘤对 BCNU 的耐药性。一致地，SWOZ2-BCNU 细胞以及 miR-21 激动剂转染细胞中 Spry2 蛋白水平显著降低，与 miR-21 表达呈负相关。si-Spry2 共转染的结果表明，miR-21 通过降低 Spry2 蛋白表达来影响神经胶质瘤对 BCNU 的耐药性。
miR-21 通过降低 Spry2 蛋白表达增强人神经胶质瘤细胞对 BCNU 的耐药性。因此，Spry2 可能成为治疗神经胶质瘤 BCNU 耐药的新靶点。
