Ma Yiming, Yu Wei, Shrivastava Anju, Alemi Farzad, Lankachandra Kamani, Srivastava Rakesh K, Shankar Sharmila
Kansas City VA Medical Center, 4801 Linwood Boulevard, Kansas City, MO 66128, USA.
Department of Oncology, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA.
Carcinogenesis. 2017 Oct 1;38(10):1047-1056. doi: 10.1093/carcin/bgx070.
Sonic hedgehog pathway is highly activated in pancreatic cancer stem cells (CSC) which play crucial roles in cancer initiation, progression and metastasis. However, the molecular mechanisms by which sanguinarine regulates pancreatic CSC characteristics is not well understood. The objectives of this study were to examine the molecular mechanisms by which sanguinarine regulates pancreatic CSC characteristics. Sanguinarine inhibited cell proliferation and colony formation and induced apoptosis through oxidative damage. Sanguinarine inhibited self-renewal capacity of pancreatic CSCs isolated from human and KrasG12D mice. Furthermore, sanguinarine suppressed epithelial-mesenchymal transition (EMT) by up-regulating E-cadherin and inhibiting N-cadherin. Significant decrease in expression level of Snail, Slug and Zeb1 corroborated the suppression of EMT in sanguinarine treated pancreatic CSCS. The ability of sanguinarine to inhibit pluripotency maintaining factors and CSC markers suggest that sanguinarine can be an effective agent for inhibiting pancreatic cancer growth and development by targeting CSCs. Furthermore, sanguinarine inhibited Shh-Gli pathway leading to modulation of Gli target genes in pancreatic CSCs. Chromatin immunoprecipitation assay demonstrated that Nanog directly binds to promoters of Cdk2, Cdk6, FGF4, c-Myc and Oct4, and sanguinarine inhibits the binding of Nanog with these genes, suggesting the direct involvement of Nanog in cell cycle, pluripotency and self-renewal. To further investigate the role of Shh-Gli-Nanog pathway, we regulated Shh signaling either by Shh protein or Nanog overexpression. Enforced activation of Shh or overexpression of Nanog counteracted the inhibitory effects of sanguinarine on pancreatic CSC proliferation, suggesting the actions of sanguinarine are mediated, at least in part, through Shh-Gli-Nanog pathway. Our studies suggest that sanguinarine can be used for the treatment and/or prevention of pancreatic cancer by targeting CSCs.
音猬因子信号通路在胰腺癌干细胞(CSC)中高度激活,而胰腺癌干细胞在癌症的起始、进展和转移中起着关键作用。然而,血根碱调节胰腺CSC特性的分子机制尚不清楚。本研究的目的是探讨血根碱调节胰腺CSC特性的分子机制。血根碱通过氧化损伤抑制细胞增殖和集落形成并诱导细胞凋亡。血根碱抑制从人和KrasG12D小鼠分离的胰腺CSC的自我更新能力。此外,血根碱通过上调E-钙黏蛋白和抑制N-钙黏蛋白来抑制上皮-间质转化(EMT)。Snail、Slug和Zeb1表达水平的显著降低证实了血根碱处理的胰腺CSC中EMT受到抑制。血根碱抑制多能性维持因子和CSC标志物的能力表明,血根碱可以通过靶向CSC成为抑制胰腺癌生长和发展的有效药物。此外,血根碱抑制Shh-Gli信号通路,导致胰腺CSC中Gli靶基因的调节。染色质免疫沉淀试验表明,Nanog直接与Cdk2、Cdk6、FGF4、c-Myc和Oct4的启动子结合,血根碱抑制Nanog与这些基因的结合,表明Nanog直接参与细胞周期、多能性和自我更新。为了进一步研究Shh-Gli-Nanog信号通路的作用,我们通过Shh蛋白或Nanog过表达来调节Shh信号。Shh的强制激活或Nanog的过表达抵消了血根碱对胰腺CSC增殖的抑制作用,表明血根碱的作用至少部分是通过Shh-Gli-Nanog信号通路介导的。我们的研究表明,血根碱可通过靶向CSC用于治疗和/或预防胰腺癌。