Ghosh Chandrayee, Paul Santanu, Dandawate Prasad, Gunewardena Sumedha S, Subramaniam Dharmalingam, West Cameron, Anant Shrikant, Dhar Animesh
Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS-66160, USA.
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS-66160, USA.
Oncotarget. 2019 Feb 22;10(16):1554-1571. doi: 10.18632/oncotarget.26704.
Super-enhancers (SEs) are unique areas of the genome which drive high-level of transcription and play a pivotal role in the cell physiology. Previous studies have established several important genes in cancer as SE-driven oncogenes. It is likely that oncogenes may hack the resident tissue regenerative program and interfere with SE-driven repair networks, leading to the specific pancreatic ductal adenocarcinoma (PDAC) phenotype. Here, we used ChIP-Seq to identify the presence of SE in PDAC cell lines. Differential H3K27AC marks were identified at enhancer regions of genes including c-MYC, MED1, OCT-4, NANOG, and SOX2 that can act as SE in non-cancerous, cancerous and metastatic PDAC cell lines. GZ17-6.02 affects acetylation of the genes, reduces transcription of major transcription factors, sonic hedgehog pathway proteins, and stem cell markers. In accordance with the decrease in Oct-4 expression, ChIP-Seq revealed a significant decrease in the occupancy of OCT-4 in the entire genome after GZ17-6.02 treatment suggesting the possible inhibitory effect of GZ17-6.02 on PDAC. Hence, SE genes are associated with PDAC and targeting their regulation with GZ17-6.02 offers a novel approach for treatment.
超级增强子(SEs)是基因组中的独特区域,可驱动高水平转录并在细胞生理学中发挥关键作用。先前的研究已确定癌症中的几个重要基因是由SE驱动的癌基因。癌基因很可能会破坏驻留组织的再生程序并干扰由SE驱动的修复网络,从而导致特定的胰腺导管腺癌(PDAC)表型。在这里,我们使用染色质免疫沉淀测序(ChIP-Seq)来鉴定PDAC细胞系中SE的存在。在包括c-MYC、MED1、OCT-4、NANOG和SOX2等基因的增强子区域鉴定到了差异H3K27AC标记,这些基因在非癌性、癌性和转移性PDAC细胞系中可作为SE。GZ17-6.02影响这些基因的乙酰化,降低主要转录因子、音猬因子信号通路蛋白和干细胞标志物的转录。与Oct-4表达的降低一致,ChIP-Seq显示在GZ17-6.02处理后,OCT-4在整个基因组中的占有率显著下降,这表明GZ17-6.02对PDAC可能具有抑制作用。因此,SE基因与PDAC相关,用GZ17-6.02靶向调控它们为治疗提供了一种新方法。