TSA通过激活STAT1信号通路上调肺癌细胞HLA-Ⅰ表达

TSA up-regulates HLA-Ⅰ expression in lung cancer cells by activating STAT1 signaling pathway

为探讨组蛋白去乙酰化酶抑制剂(histone deacetylase inhibitor, HDACI)——曲古抑菌素(trichostatin A,TSA)上调肺癌细胞HLA-Ⅰ表达的作用机制,利用CCK-8试验确定TSA处理A549细胞、H520细胞的最适药物浓度,RT-PCR、Western blotting分别检测TSA处理细胞后HLA-Ⅰ、信号传导及转录激活因子1(signal transducers and activators of transcription 1,STAT1)在基因和蛋白水平的表达。为进一步探究TSA上调HLA-I表达的机制,设置加药时间梯度检测TSA作用后磷酸化STAT1(phospho-STAT1,p-STAT1)的表达,同时采用核质分离试验检测TSA处理后STAT1核质的表达变化,最后通过siRNA试验检测干扰STAT1后HLA-Ⅰ的表达变化。结果显示,在A549细胞和H520细胞中,TSA的最适药物浓度是50 nmol/L;通过RT-PCR、Western blotting检测发现,TSA可以上调HLA-Ⅰ表达,p-STAT1的表达增强说明STAT1通路被TSA激活;核质分离试验证明,TSA可以促进STAT1入核;siRNA试验显示,在干扰STAT1后HLA-Ⅰ表达下调。以上结果提示,TSA通过激活STAT1信号通路上调肺癌细胞HLA-Ⅰ表达。

This study is focused on the mechanism of up-regulation of HLA-Ⅰexpression in lung cancer cells by histone deacetylase inhibitor(HDACI)—trichostatin A(TSA). CCK-8 was used to determine the optimum drug concentration of TSA. After treatment with TSA, the expression of HLA-Ⅰ, signal transducers and activators of transcription 1(STAT1) were detected by RT-PCR and Western blotting, and the expression of phospho-STAT1(p-STAT1) was detected by setting the dosing time gradient. In order to explore the underlying molecular mechanisms, we performed a nuclear and cytoplasm separation test to detect the expression of STAT1 in the cytoplasmic and nucleus respectively after TSA treatment. Finally, siRNA test was used to detect the protein expression of HLA-Ⅰ after interfering with si-STAT1. The results showed that in both A549 and H520 cell lines, the optimal drug concentration of TSA was 50 nmol/L;by RT-PCR and Western blotting, we found that the expression of HLA-Ⅰ could be up-regulated after treatment with TSA, and the enhanced expression of P-STAT1 indicated that the STAT1 pathway was activated by TSA;nuclear and cytoplasmic separation test showed that TSA could promote the nuclear expression of STAT1;after interfering with si-STAT1,the expression of HLA-Ⅰ was decreased. Together, these results suggest that TSA up-regulates HLA-Ⅰ expression by activating STAT1 signaling pathway in lung cancer cells.