Department of Biochemistry and Immunology, FMRP - University of São Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirão Preto, SP, Brazil; Center for Cell Based Therapy, Hemotherapy Center of Ribeirão Preto, Rua Tenente Catão Roxo, 2501, 14051-140 Ribeirão Preto, SP, Brazil.
Department of Biochemistry and Immunology, FMRP - University of São Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirão Preto, SP, Brazil.
J Proteomics. 2020 May 15;219:103734. doi: 10.1016/j.jprot.2020.103734. Epub 2020 Mar 19.
Epithelial to Mesenchymal Transition (EMT) is a normal cellular process that is also triggered during cancer progression and metastasis. EMT induces cellular and microenviromental changes, resulting in loss of epithelial features and acquisition of mesenchymal phenotypes. The growth factor TGFβ and the transcription factor SNAIL1 (SNAIL) have been described as inducers of EMT. Here, we carried out an EMT model with non-tumorigenic cell line MCF-10A induced with the TGFβ2 specific isoform of TGF protein family. The model was validated by molecular, morphological and functional experiments and showed correlation with the up-regulation of SNAIL. In order to identify additional regulators of EMT in this non-tumorigenic model, we explored quantitative proteomics, which revealed the Ubiquitin carboxyl-terminal hydrolase 47 (USP47) as one of the top up-regulated proteins. USP47 has a known role in cell growth and genome integrity, but not previously correlated to EMT. After validating USP47 alterations using MRM and antibody-based assays, we demonstrated that the chemical inhibition of USP47 with the inhibitor P5091 reduced expression of EMT markers and reverted morphological changes in MCF-10A cells undergoing EMT. These results support the involvement of USP47 in our EMT model as well as potential applications of deubiquitinases as therapeutic targets for cancer progression management. BIOLOGICAL SIGNIFICANCE: Metastasis is responsible for most cancer-associated mortality. Additionally, metastasis requires special attention, as the cellular transformations make treatment at this stage very difficult or occasionally impossible. Early steps in cancer metastasis involve the ability to detach from the solid tumor mass and invade the surrounding stromal tissues through cohesive migration, or a mesenchymal or amoeboid invasion. One of the first steps for metastatic cascade is denominated epithelial to mesenchymal transition (EMT), which can be triggered by different factors. Here, our efforts were directed to better understand this process and identify new pathways that contributes for acquisition of EMT, mainly focused on post translational modifications related to ubiquitin proteasome system. Our model of EMT induction by TGFβ2 mimics early stage of metastatic cancer in epithelial breast cells and a proteomic study carried out for such model demonstrates that the deubiquitinase enzyme USP47 acts in SNAIL stabilization, one of the most important transcription factors for EMT phenotype acquisition and consequent metastasis. In addition, the inhibiton of USP47 with P5091, reverted the EMT phenotype. Together the knowledge of such processes of cancer progression and regulation can help in designing new strategies for combined therapies for control of cancer in early stages.
上皮间质转化(EMT)是一种正常的细胞过程,也在癌症进展和转移过程中被触发。EMT 诱导细胞和微环境变化,导致上皮特征的丧失和间充质表型的获得。生长因子 TGFβ 和转录因子 SNAIL1(SNAIL)已被描述为 EMT 的诱导剂。在这里,我们使用 TGFβ 蛋白家族的 TGFβ2 特异性同工型诱导非肿瘤细胞系 MCF-10A 进行 EMT 模型。通过分子、形态和功能实验验证了该模型,并与 SNAIL 的上调相关。为了在这个非肿瘤模型中鉴定 EMT 的其他调节剂,我们探索了定量蛋白质组学,发现泛素羧基末端水解酶 47(USP47)是上调最多的蛋白质之一。USP47 在细胞生长和基因组完整性方面具有已知作用,但以前与 EMT 无关。在用 MRM 和基于抗体的测定法验证 USP47 的改变后,我们证明用抑制剂 P5091 抑制 USP47 的化学抑制减少了 EMT 标志物的表达,并使正在经历 EMT 的 MCF-10A 细胞的形态变化逆转。这些结果支持 USP47 参与我们的 EMT 模型,以及去泛素化酶作为癌症进展管理治疗靶点的潜在应用。生物学意义:转移是大多数与癌症相关的死亡的原因。此外,转移需要特别关注,因为细胞转化使在这个阶段的治疗非常困难或偶尔不可能。癌症转移的早期步骤包括通过粘着迁移或间质或变形虫样入侵来从实体肿瘤块中分离出来并侵入周围基质组织的能力。转移级联的第一步之一被称为上皮间质转化(EMT),它可以被不同的因素触发。在这里,我们的努力旨在更好地理解这个过程,并确定有助于 EMT 获得的新途径,主要集中在与泛素蛋白酶体系统相关的翻译后修饰上。我们用 TGFβ2 诱导 EMT 的模型模拟了上皮性乳腺癌中转移癌的早期阶段,对该模型进行的蛋白质组学研究表明,去泛素酶 USP47 作用于 EMT 表型获得的最重要转录因子之一 SNAIL 的稳定,从而导致 EMT 和随后的转移。此外,用 P5091 抑制 USP47 使 EMT 表型逆转。癌症进展和调控过程的知识可以帮助设计用于控制早期癌症的联合治疗的新策略。