miR-590-3p靶向微管蛋白辅助因子A（TBCA）调控EMT介导的肾透明细胞癌恶性进展机制研究

The recurrence and metastasis of clear cell renal cell carcinoma (ccRCC) is the main cause of death of the disease. As we know, EMT plays important roles in invasive and migration of cancer cells. It have been demonstrated that TGFβ/Smads mediated EMT is tightly related to the progression and metastasis of ccRCC. Moreover, microtubule regulated EMT by interacting with Smad2 and Smad3, which are key molecules in TGF-β pathway. The latest studies showed that Tubulin cofactor A (TBCA) plays crucial roles in modulating the stability of microtubule. Our preliminary data showed an aberrant expression of TBCA in ccRCC and a positive regulation in promoting ccRCC cells’ proliferation. Additionally, we already identified miR-590-3p as a potential upstream factor of TBCA by miRNA screening. On this basis, in this study, we aim to determine the targeting effect of miR-590-3p on TBCA, and uncover the molecular mechanism of miR-590-3p/TBCA regulating EMT of ccRCC cells through TGF-β pathway, which resulting in the progression and metastasis of ccRCC. Then confirm the effect that miR-590-3p/TBCA may influence TGF-β pathway by affecting the subcellular localization and phosphorylation level of Smad2 and Smad3. Importantly, we will determine the correlation of miR-590-3p/TBCA expression and malignancy status in a large number of samples from individuals with ccRCC to further confirm this novel mechanism. Thus it may represent a novel diagnosis and therapeutic target for ccRCC and other type of renal carcimona with the same underlying mechanism.

肾癌的复发与转移是其致死的主要原因。EMT是肿瘤浸润转移的重要途径，研究显示TGF-β/Smads介导的EMT与肾癌的进展转移密切相关，且细胞微管可作用于TGF-β通路中重要分子Smad2/3调控EMT进程。微管蛋白辅助因子（TBCA）是调控细胞微管稳定性的重要蛋白。我们的前期研究显示，TBCA在肾癌组织和细胞系中异常表达，且对肾癌细胞的增殖与侵袭有正向调控作用，并发现了TBCA上游调节因子miR-590-3p。基于此，本研究拟明确miR-590-3p对TBCA的靶向作用机制，阐明肾癌进展与转移中miR-590-3p/TBCA通过调控TGF-β/Smads这一新的信号通路在介导肾癌细胞EMT进程，促进肾癌恶性进展中的重要作用。更重要的是，本研究拟利用大量肾癌标本分析miR-590-3p/TBCA的差异性表达与肾癌恶性程度、转移及预后的相关性，为肾癌的早期诊断，预后及治疗提供新的诊疗靶标。

肾癌的复发与转移是其致死的主要原因。EMT是肿瘤浸润转移的重要途径，研究显示TGF-β/Smads介导的EMT与肾癌的进展转移密切相关，且细胞微管可作用于TGF-β通路中重要分子Smad2/3调控EMT进程。微管蛋白辅助因子（TBCA）是调控细胞微管稳定性的重要蛋白。我们的前期研究显示，TBCA在肾癌组织和细胞系中异常表达，且对肾癌细胞的增殖与侵袭有正向调控作用，并发现了TBCA受上游调节因子miRNA的调控。基于此，本研究筛查并明确了miR-126-5p作为TBCA上游的调控因子，揭示了miR-126-5p靶向TBCA的调控机制，同时证实了TBCA及其上游miR-126-5p对肾癌细胞增殖、迁移和侵袭以及细胞极性和形态学等影响；阐明了miR126-5p/TBCA可通过作用于TGF-β通路中Smad2/3/4而诱发肾癌细胞发生EMT这一分子机制；通过组织病理学研究，利用临床标本分析TBCA在肾癌中的表达水平与肾癌临床分期参数及预后之间具有一定相关性，同时发现TBCA能够诱导肾癌细胞对Sorafenib耐药，而TGF-β/Smad通路的抑制剂SB431542能够抑制TBCA诱导肾癌细胞对Sorafenib的耐药。更重要的是，本研究通过利用大量肾癌标本分析miR-126-5p/TBCA的差异性表达与肾癌恶性程度、转移及预后的相关性，有望为肾癌的早期诊断，预后及治疗提供新的诊疗靶标。