Luo Qingying, Gu Shiyan, Zhang Zunzhen
College of Food Science, Sichuan Agricultural University, Yaan 625014, China.
Wei Sheng Yan Jiu. 2017 May;46(3):389-395.
To explore if inhibiting the expression of wild-type p53-induced phosphatase 1( WIP1) could enhance the sensitivity of A549 cells to arsenic.
To inhibit expression of WIP1, WIP1 siRNA was transferred into A549 cells by using Lipofectamine 2000. Then the protein expression levels of P53 phosphorylation proteins and their downstream effectors were detected by western-blot analysis. Cell apoptosis were assessed by Annexin V-FITC stain assay. The sensitivity of transferred cells to arsenic was detected by using MTT assay.
The mRNA and protein expression level of WIP1 were all decreased by 70 % in A549 cells transferred with WIP1 siRNA. Western-blot analysis indicated that P53 phosphorylation process was much accelerated in WIP1-inhibited cells after arsenic treatment. For example, compared to control cells, an significant decrease in P53 ser15 expression and an increase in P53 ser46 expression was found in WIP1-inhibited cells when treated with As_2O_3( 5-40 μmol/L). In addition, compared to control group, the expression of P21 decreased whereas PUMA increased in WIP1-inhibited cells when treated with As_2O_3( 10-40 μmol/L). Cell viability of WIP1-inhibited cells after As_2O_3 treatment( 5-40 μmol/L) was significantly higher than that of the control group, which may be due to a high apoptosis rate in WIP1-inhibited cells.
WIP1 could be used as a new target in arsenic-base anticancer therapies.
探讨抑制野生型p53诱导磷酸酶1（WIP1）的表达是否能增强A549细胞对砷的敏感性。
为抑制WIP1的表达，使用Lipofectamine 2000将WIP1 siRNA转染至A549细胞中。然后通过蛋白质免疫印迹分析检测P53磷酸化蛋白及其下游效应分子的蛋白质表达水平。采用Annexin V-FITC染色法评估细胞凋亡情况。使用MTT法检测转染细胞对砷的敏感性。
转染WIP1 siRNA的A549细胞中，WIP1的mRNA和蛋白质表达水平均下降了70%。蛋白质免疫印迹分析表明，砷处理后，WIP1抑制的细胞中P53磷酸化过程显著加速。例如，与对照细胞相比，用As₂O₃（5 - 40 μmol/L）处理时，WIP1抑制的细胞中P53 ser15表达显著降低，P53 ser46表达增加。此外，与对照组相比，用As₂O₃（10 - 40 μmol/L）处理时，WIP1抑制的细胞中P21表达下降，而PUMA表达增加。As₂O₃处理（5 - 40 μmol/L）后，WIP1抑制的细胞的细胞活力显著高于对照组，这可能是由于WIP1抑制的细胞凋亡率较高。
WIP1可作为砷基抗癌治疗的新靶点。
