胰腺癌仍然是最致命的癌症之一,而且较少发现有效的治疗方案。虽然在许多肿瘤细胞,包括胰腺癌细胞中观察到泛素特异性蛋白酶14(ubiquitin specific peptidase 14,USP14)的过度表达,但它在胰腺癌中的确切作用仍未得到较好的阐明。我们研...胰腺癌仍然是最致命的癌症之一,而且较少发现有效的治疗方案。虽然在许多肿瘤细胞,包括胰腺癌细胞中观察到泛素特异性蛋白酶14(ubiquitin specific peptidase 14,USP14)的过度表达,但它在胰腺癌中的确切作用仍未得到较好的阐明。我们研究了USP14在胰腺癌中的生物学功能及其分子机制。对癌症基因组图谱数据库(The Cancer Genome Atlas,TCGA)的分析显示USP14在胰腺癌组织中高度表达,进一步探究发现,其表达水平与患者的预后呈负相关。利用shRNAUSP14慢病毒建立了稳定的USP14敲低胰腺癌细胞系,通过CCK8、克隆形成实验、划痕和Transwell试验发现,USP14敲低抑制了胰腺癌细胞的增殖和迁移能力。在胰腺癌细胞SW1990和MIAPaCa2中蛋白质印迹结果表明,下调USP14的表达导致细胞周期蛋白D3(cyclin D3)水平下降,而过表达USP14会增加细胞周期蛋白D3表达水平。此外,免疫共沉淀证明,USP14与细胞周期蛋白D3相互作用,泛素化结果显示,USP14的过表达降低了细胞周期蛋白D3的泛素化水平。并且在SW1990胰腺癌细胞中,CRISPR/Cas9介导的USP14敲除导致细胞周期蛋白D3水平下降。这些发现表明,USP14通过与细胞周期蛋白D3的相互作用促进了胰腺癌细胞的增殖和迁移能力,凸显了USP14作为胰腺癌的潜在治疗靶点。展开更多
MicroRNAs play pivotal roles in the regulation of both innate and adaptive immune responses. In this study, we found that activation of toll-like receptor 4 (TLR4) rapidly increased the level of microRNA-124 (miR- ...MicroRNAs play pivotal roles in the regulation of both innate and adaptive immune responses. In this study, we found that activation of toll-like receptor 4 (TLR4) rapidly increased the level of microRNA-124 (miR- 124) in lipopolysaccharide (LPS)-treated macrophages and mice. MiR-124 knockdown significantly increased the production of the pro-inflammatory cytokine TNF-oL at the post-transcriptional level in LPS-triggered macrophages. Furthermore, miR-124 knockdown or overexpression significanly increased or decreased the protein stability of TNF- α. We found miR-124 directly targeted ubiquitin-specific proteases 2 (USP2) and 14 (USP14), two components of deubiquitinating enzymes. Knockdown of USP2 and USP14 attenuated the miR-124-mediated protein degradation of TNF-α. Together, our data identify miR-124 as an important feedback negative regulator for LPS-induced pro- duction of TNF-α by targeting USP2 and USP14, thus outlining new mechanisms for fine-tuning the TLR-triggered inflammatory response.展开更多
文摘胰腺癌仍然是最致命的癌症之一,而且较少发现有效的治疗方案。虽然在许多肿瘤细胞,包括胰腺癌细胞中观察到泛素特异性蛋白酶14(ubiquitin specific peptidase 14,USP14)的过度表达,但它在胰腺癌中的确切作用仍未得到较好的阐明。我们研究了USP14在胰腺癌中的生物学功能及其分子机制。对癌症基因组图谱数据库(The Cancer Genome Atlas,TCGA)的分析显示USP14在胰腺癌组织中高度表达,进一步探究发现,其表达水平与患者的预后呈负相关。利用shRNAUSP14慢病毒建立了稳定的USP14敲低胰腺癌细胞系,通过CCK8、克隆形成实验、划痕和Transwell试验发现,USP14敲低抑制了胰腺癌细胞的增殖和迁移能力。在胰腺癌细胞SW1990和MIAPaCa2中蛋白质印迹结果表明,下调USP14的表达导致细胞周期蛋白D3(cyclin D3)水平下降,而过表达USP14会增加细胞周期蛋白D3表达水平。此外,免疫共沉淀证明,USP14与细胞周期蛋白D3相互作用,泛素化结果显示,USP14的过表达降低了细胞周期蛋白D3的泛素化水平。并且在SW1990胰腺癌细胞中,CRISPR/Cas9介导的USP14敲除导致细胞周期蛋白D3水平下降。这些发现表明,USP14通过与细胞周期蛋白D3的相互作用促进了胰腺癌细胞的增殖和迁移能力,凸显了USP14作为胰腺癌的潜在治疗靶点。
文摘MicroRNAs play pivotal roles in the regulation of both innate and adaptive immune responses. In this study, we found that activation of toll-like receptor 4 (TLR4) rapidly increased the level of microRNA-124 (miR- 124) in lipopolysaccharide (LPS)-treated macrophages and mice. MiR-124 knockdown significantly increased the production of the pro-inflammatory cytokine TNF-oL at the post-transcriptional level in LPS-triggered macrophages. Furthermore, miR-124 knockdown or overexpression significanly increased or decreased the protein stability of TNF- α. We found miR-124 directly targeted ubiquitin-specific proteases 2 (USP2) and 14 (USP14), two components of deubiquitinating enzymes. Knockdown of USP2 and USP14 attenuated the miR-124-mediated protein degradation of TNF-α. Together, our data identify miR-124 as an important feedback negative regulator for LPS-induced pro- duction of TNF-α by targeting USP2 and USP14, thus outlining new mechanisms for fine-tuning the TLR-triggered inflammatory response.