DYRK1A通过调控上皮间质转化影响肝细胞癌转移的分子机制研究

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human malignancies in China. Death from HCC is primarily due to late-stage disease, which is characterized by invasion, metastasis, and postsurgical recurrence. The mechanism underlying remains unclear, but emerging evidence suggest that epithelial–mesenchymal transitions (EMTs) play important roles in HCC metastasis and recurrence. Therefore, it is of great clinical significance to find a potential therapeutic target for the regulation of EMT. Our preliminary study showed that DYRK1A protein expression level was closely related to EMT in HCC, and depletion of DYRK1A could reverse the TGF-β-induced EMT. We also found the DYRK1A inhibitor harmine could attenuate EMT and decrease cell migration in HCC cells,implicating its potential of suppressing HCC metastasis. In this project, we will further explore the role of DYRK1A expression in HCC metastasis and EMT, and dissect the regulation of TGF-β/Smad signaling by DYRK1A by utilizing harmine as a small molecular probe. In addition, gene/protein chips and Mass spectrometry will be employed to analyze the signaling cross-talk and networks involved in DYRK1A-mediated HCC EMT and metastasis so as to uncover the new bilogical functions of DYRK1A. In conclusion, our study will determine the role of DYRK1A in the EMT and metastasis of HCC, and promote the development of new targets and agents for antimetastatic therapies.

肝细胞癌（HCC）转移和复发是肝癌相关死亡的主要原因，而上皮间质转化（EMT）与HCC的转移和不良预后密切相关。因此发现调控EMT发生的潜在治疗靶标具有重要的临床意义。申请人的前期研究表明DYRK1A的表达与HCC的EMT发生密切相关，抑制DYRK1A蛋白的表达能逆转TGF-β诱导的EMT，且DYRK1A抑制剂Harmine可有效抑制EMT和HCC细胞的迁移运动，具备潜在的抗肿瘤转移效果。基于此，本课题将进一步探究DYRK1A在HCC的EMT发生与转移中的功能，并以Harmine等为小分子探针，探讨DYRK1A对TGF-β/Smad信号通路的调控方式，同时借助芯片和生物质谱技术深刻描绘DYRK1A调控EMT和HCC细胞转移的分子信号网络，发现DYRK1A新的生物学功能，并阐明DYRK1A作为抑制EMT和抗HCC转移潜在靶标的可行性，为发展新的抗HCC转移策略提供理论依据。

本课题组发现DYRK1A参与肝癌、肺癌的恶性进展和药物敏感性，阐明了DYRK1A在肿瘤发展中的生物学功能，明确了DYRK1A作为抗肿瘤药物全新靶标的可行性，具体如下：.（1）DYRK1A表达与肝癌恶性进展的相关性。相比于正常组织，DYRK1A在肝癌患者肿瘤组织中呈高表达；随着肝癌患者肿瘤组织转移能力增加，DYRK1A呈现高表达；敲低DYRK1A抑制肝癌细胞迁移和侵袭能力，同时DYRK1A敲低能抑制肝癌细胞N-cadherin表达和促进E-cadherin表达，DYRK1A抑制剂harmine显著抑制肝癌细胞的迁移、侵袭能力和EMT的发生；在临床肝癌样本中，DYRK1A与TGF-β-SMAD2/3信号通路中的重要蛋白呈现共表达，DYRK1A能促进TGF-β-SMAD2/3信号通路，促进肝癌细胞转移。因此，DYRK1A有望成为克服肝癌转移的重要分子靶标。.（2）DYRK1A表达与Bcl-2抑制剂抗肺癌活性相关性。鉴于DYRK1A在肝癌恶性进展中扮演了重要的角色，因此我们猜测DYRK1A在其他类型的肿瘤恶性进展中起到关键作用。Mcl-1的过表达促进实体瘤对Bcl-2抑制剂产生耐药性。我们发现DYRK1A正向调控NSCLC细胞Mcl-1的表达；进一步，DYRK1A与Mcl-1存在相互作用，DYRK1A与Mcl-1在肺癌患者肿瘤样品中存在共表达；DYRK1A和Mcl-1过表达能促进NSCLC细胞对Bcl-2抑制剂的耐药；DYRK1A抑制能增强了Bcl-2抑制剂抗NSCLC活性。因此，DYRK1A结合Mcl-1，参与Mcl-1稳定性，影响Bcl-2抑制剂抗NSCLC活性。.（3）DYRK1A表达与AZD9291抗肺癌活性相关性。EGFR-TKIs对EGFR野生型NSCLC患者不敏感，亟需开发新型的靶向治疗合用配伍。高表达DYRK1A与肺癌患者的不良预后相关；harmine抑制NSCLC细胞增殖；DYRK1A影响EGFR野生型NSCLC细胞STAT3/EGFR/Met信号；抑制DYRK1A抑制EGFR/Met信号通路增敏AZD9291抗EGFR野生型NSCLC活性。因此，DYRK1A可作为增敏AZD9291抗EGFR野生型NSCLC活性的有效靶标。.总之，DYRK1A在肿瘤恶性进展和化疗耐药中均扮演了重要的角色，而DYRK1A能作为克服肿瘤转移和耐药的有效靶点。