Mishra Vivek Kumar, Subramaniam Malayannan, Kari Vijayalakshmi, Pitel Kevin S, Baumgart Simon J, Naylor Ryan M, Nagarajan Sankari, Wegwitz Florian, Ellenrieder Volker, Hawse John R, Johnsen Steven A
Department of General, Visceral and Pediatric Surgery, University Medical Center Göttingen, Göttingen Center for Molecular Biosciences, Göttingen, Germany.
Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota.
Cancer Res. 2017 May 1;77(9):2387-2400. doi: 10.1158/0008-5472.CAN-16-2589. Epub 2017 Mar 1.
TGFβ-SMAD signaling exerts a contextual effect that suppresses malignant growth early in epithelial tumorigenesis but promotes metastasis at later stages. Longstanding challenges in resolving this functional dichotomy may uncover new strategies to treat advanced carcinomas. The Krüppel-like transcription factor, KLF10, is a pivotal effector of TGFβ/SMAD signaling that mediates antiproliferative effects of TGFβ. In this study, we show how KLF10 opposes the prometastatic effects of TGFβ by limiting its ability to induce epithelial-to-mesenchymal transition (EMT). KLF10 depletion accentuated induction of EMT as assessed by multiple metrics. KLF10 occupied GC-rich sequences in the promoter region of the EMT-promoting transcription factor SLUG/SNAI2, repressing its transcription by recruiting HDAC1 and licensing the removal of activating histone acetylation marks. In clinical specimens of lung adenocarcinoma, low KLF10 expression associated with decreased patient survival, consistent with a pivotal role for KLF10 in distinguishing the antiproliferative versus prometastatic functions of TGFβ. Our results establish that KLF10 functions to suppress TGFβ-induced EMT, establishing a molecular basis for the dichotomy of TGFβ function during tumor progression. .
转化生长因子β(TGFβ)-SMAD信号传导发挥着一种情境依赖性作用,在上皮肿瘤发生早期抑制恶性生长,但在后期促进转移。解决这种功能二分法方面长期存在的挑战可能会揭示治疗晚期癌症的新策略。类 Kruppel 转录因子 KLF10 是 TGFβ/SMAD 信号传导的关键效应因子,介导 TGFβ 的抗增殖作用。在本研究中,我们展示了 KLF10 如何通过限制 TGFβ 诱导上皮-间质转化(EMT)的能力来对抗其促转移作用。通过多种指标评估,KLF10 的缺失增强了 EMT 的诱导。KLF10 占据了促进 EMT 的转录因子 SLUG/SNAI2 启动子区域富含 GC 的序列,通过招募组蛋白去乙酰化酶 1(HDAC1)并促进去除激活的组蛋白乙酰化标记来抑制其转录。在肺腺癌临床标本中,KLF10 低表达与患者生存率降低相关,这与 KLF10 在区分 TGFβ 的抗增殖与促转移功能中的关键作用一致。我们的结果表明,KLF10 具有抑制 TGFβ 诱导的 EMT 的功能,为肿瘤进展过程中 TGFβ 功能的二分法奠定了分子基础。