Oxidative Stress Converts Benign Lesions to Cancer via a Self-Amplifying NRF2-EZH2 Loop [Quantseq_Nrf2Kras]
Ontology highlight
ABSTRACT: Whether oxidative stress (OxS) acts mutationally or epigenetically to increase cancer risk is unknown. Pancreatic ductal carcinoma (PDAC) evolves from benign, low-grade PanIN (pancreatic intraepithelial neoplasia) lesions that frequently express oncogenic KRAS. Postulating that known risk factors convert benign PanIN to malignant progenitors via OxS and epigenetic mechanisms, we established a novel system to test this hypothesis. Transient incubation of organoids, derived from pancreata with KrasG12D-induced low-grade PanIN, with H2O2 triggered irreversible malignant conversion mediated by an epigenetic network composed of NRF2, its direct transcriptional target EZH2, and EZH2-interacting transcription factors. Pharmacological or genetic activation of this network, maintained by a single NRF2 site in the EZH2 promoter, also triggered rapid malignant conversion and upregulation of malignancy-supportive metabolic genes that remained elevated in established PDAC.
Project description:Whether oxidative stress (OxS) acts mutationally or epigenetically to increase cancer risk is unknown. Pancreatic ductal carcinoma (PDAC) evolves from benign, low-grade PanIN (pancreatic intraepithelial neoplasia) lesions that frequently express oncogenic KRAS. Postulating that known risk factors convert benign PanIN to malignant progenitors via OxS and epigenetic mechanisms, we established a novel system to test this hypothesis. Transient incubation of organoids, derived from pancreata with KrasG12D-induced low-grade PanIN, with H2O2 triggered irreversible malignant conversion mediated by an epigenetic network composed of NRF2, its direct transcriptional target EZH2, and EZH2-interacting transcription factors. Pharmacological or genetic activation of this network, maintained by a single NRF2 site in the EZH2 promoter, also triggered rapid malignant conversion and upregulation of malignancy-supportive metabolic genes that remained elevated in established PDAC.
Project description:Whether oxidative stress (OxS) acts mutationally or epigenetically to increase cancer risk is unknown. Pancreatic ductal carcinoma (PDAC) evolves from benign, low-grade PanIN (pancreatic intraepithelial neoplasia) lesions that frequently express oncogenic KRAS. Postulating that known risk factors convert benign PanIN to malignant progenitors via OxS and epigenetic mechanisms, we established a novel system to test this hypothesis. Transient incubation of organoids, derived from pancreata with KrasG12D-induced low-grade PanIN, with H2O2 triggered irreversible malignant conversion mediated by an epigenetic network composed of NRF2, its direct transcriptional target EZH2, and EZH2-interacting transcription factors. Pharmacological or genetic activation of this network, maintained by a single NRF2 site in the EZH2 promoter, also triggered rapid malignant conversion and upregulation of malignancy-supportive metabolic genes that remained elevated in established PDAC.
Project description:Whether oxidative stress (OxS) acts mutationally or epigenetically to increase cancer risk is unknown. Pancreatic ductal carcinoma (PDAC) evolves from benign, low-grade PanIN (pancreatic intraepithelial neoplasia) lesions that frequently express oncogenic KRAS. Postulating that known risk factors convert benign PanIN to malignant progenitors via OxS and epigenetic mechanisms, we established a novel system to test this hypothesis. Transient incubation of organoids, derived from pancreata with KrasG12D-induced low-grade PanIN, with H2O2 triggered irreversible malignant conversion mediated by an epigenetic network composed of NRF2, its direct transcriptional target EZH2, and EZH2-interacting transcription factors. Pharmacological or genetic activation of this network, maintained by a single NRF2 site in the EZH2 promoter, also triggered rapid malignant conversion and upregulation of malignancy-supportive metabolic genes that remained elevated in established PDAC.
Project description:Enhancer of Zeste Homologue 2 (EZH2) is part of the Polycomb Repressor Complex 2, which induces trimethylation of lysine 27 on histone 3 (H3K27me3) and promotes genes repression. EZH2 is overexpressed in many cancers including pancreatic ductal adenocarcinoma (PDAC). Previous studies in mice attributed both pro-oncogenic and tumor suppressive functions to EZH2. Deletion of the EZH2 enhancesde novoKRAS-driven neoplasia following pancreatic injury by preventing acinar cell regeneration, while increased EZH2 expression in PDAC is correlated to poor prognosis, suggesting a context-dependant effect for EZH2 in PDAC progression. In this study, we examined EZH2 function in pre- and early neoplastic stages of PDAC. Using an inducible model to generate deletion of EZH2 only in adult acinar cells (EZH2DSET), we showed loss of EZH2 activity did not prevent acinar cell regeneration in the absence of oncogenic KRAS (KRASG12D), nor lead to increased PanIN formation in the presence of KRASG12Din adult mice. However, loss of EZH2 did reduce recruitment of inflammatory cells and, when combined with a PDAC model, promoted widespread PDAC progression. Loss of EZH2 function also correlated to remodeling of the tumor microenvironment, which favors cancer cell progression. This study suggests expression of EZH2 in adult acinar cells restricts PDAC initiation and progression by affecting both the tumour microenvironment and acinar cell differentiation.
Project description:Enhancer of Zeste Homologue 2 (EZH2) is part of the Polycomb Repressor Complex 2, which induces trimethylation of lysine 27 on histone 3 (H3K27me3) and promotes genes repression. EZH2 is overexpressed in many cancers including pancreatic ductal adenocarcinoma (PDAC). Previous studies in mice attributed both pro-oncogenic and tumor suppressive functions to EZH2. Deletion of the EZH2 enhancesde novoKRAS-driven neoplasia following pancreatic injury by preventing acinar cell regeneration, while increased EZH2 expression in PDAC is correlated to poor prognosis, suggesting a context-dependant effect for EZH2 in PDAC progression. In this study, we examined EZH2 function in pre- and early neoplastic stages of PDAC. Using an inducible model to generate deletion of EZH2 only in adult acinar cells (EZH2DSET), we showed loss of EZH2 activity did not prevent acinar cell regeneration in the absence of oncogenic KRAS (KRASG12D), nor lead to increased PanIN formation in the presence of KRASG12Din adult mice. However, loss of EZH2 did reduce recruitment of inflammatory cells and, when combined with a PDAC model, promoted widespread PDAC progression. Loss of EZH2 function also correlated to remodeling of the tumor microenvironment, which favors cancer cell progression. This study suggests expression of EZH2 in adult acinar cells restricts PDAC initiation and progression by affecting both the tumour microenvironment and acinar cell differentiation.
Project description:Meningiomas are common brain tumors that are classified into three World Health Organization grades (Grade I: benign, Grade II: atypical and Grade III: malignant) and are molecularly ill-defined tumors. The purpose of this study was identify microRNA (miRNA) molecular signatures unique to the different grades of meningiomas correlating them to prognosis. We have used a miRNA expression microarray to show that meningiomas of all three grades fall into two main molecular groups designated “benign” and “malignant” meningiomas. While all typical meningiomas fall into the benign group and all anaplastic meningiomas fall into the malignant group, atypical meningiomas distribute into either one of these groups. We have identified a miRNA signature that distinguishes benign meningiomas from malignant meningiomas.
Project description:Meningiomas are common brain tumors that are classified into three World Health Organization grades (Grade I: benign, Grade II: atypical and Grade III: malignant) and are molecularly ill-defined tumors. The purpose of this study was identify microRNA (miRNA) molecular signatures unique to the different grades of meningiomas correlating them to prognosis. We have used a miRNA expression microarray to show that meningiomas of all three grades fall into two main molecular groups designated “benign” and “malignant” meningiomas. While all typical meningiomas fall into the benign group and all anaplastic meningiomas fall into the malignant group, atypical meningiomas distribute into either one of these groups. We have identified a miRNA signature that distinguishes benign meningiomas from malignant meningiomas. We studied the gene expression profiles of 340 mammalian miRNAs in 37 primary meningioma tumors by means of DNA microarrays.
Project description:This study introduces a new imaging, spatial transcriptomics (ST), and single-cell RNA-sequencing (scRNA-seq) integration pipeline to characterize neoplastic cell state transitions during tumorigenesis. Our semi-supervised analysis pipeline was applied to examine pancreatic intraepithelial neoplasias (PanIN), the most frequent premalignant lesions that can develop into pancreatic adenocarcinoma (PDAC). Their strict diagnosis on FFPE samples has limited previous characterization of human PanINs within their microenvironment through single-cell approaches. We leverage unbiased whole transcriptome FFPE spatial profiling to enable this characterization in a rare cohort of matched low-grade and high-grade PanIN lesions to track progression and map cellular phenotypes relative to scRNA-seq data of advanced PDAC tumors. We demonstrate that cancer associated fibroblasts (CAF), including antigen-presenting CAFs (apCAF), are located close to PanINs. We further observed a transition from CAF-related inflammatory signaling to cellular proliferation during PanIN progression. We use these findings to guide panel design to perform single-cell validation with high-dimensional imaging proteomics and transcriptomics technologies. Altogether, our pipeline for spatial multi-omics characterization provides a resource for future PanIN studies. Moreover, our semi-supervised learning framework to spatial multi-omics has broad applicability across cancer types to decipher the spatiotemporal dynamics of carcinogenesis.
Project description:This study introduces a new imaging, spatial transcriptomics (ST), and single-cell RNA-sequencing (scRNA-seq) integration pipeline to characterize neoplastic cell state transitions during tumorigenesis. Our semi-supervised analysis pipeline was applied to examine pancreatic intraepithelial neoplasias (PanIN), the most frequent premalignant lesions that can develop into pancreatic adenocarcinoma (PDAC). Their strict diagnosis on FFPE samples has limited previous characterization of human PanINs within their microenvironment through single-cell approaches. We leverage unbiased whole transcriptome FFPE spatial profiling to enable this characterization in a rare cohort of matched low-grade and high-grade PanIN lesions to track progression and map cellular phenotypes relative to scRNA-seq data of advanced PDAC tumors. We demonstrate that cancer associated fibroblasts (CAF), including antigen-presenting CAFs (apCAF), are located close to PanINs. We further observed a transition from CAF-related inflammatory signaling to cellular proliferation during PanIN progression. We use these findings to guide panel design to perform single-cell validation with high-dimensional imaging proteomics and transcriptomics technologies. Altogether, our pipeline for spatial multi-omics characterization provides a resource for future PanIN studies. Moreover, our semi-supervised learning framework to spatial multi-omics has broad applicability across cancer types to decipher the spatiotemporal dynamics of carcinogenesis.
Project description:The aim of this experiment is to unravel PDAC biology and phospho-print based on aberrant kinase activities and proteome alterations. For this we will perform pTYyrIP, Bravo_IMAC, and protein expression data of n=56 tissues encompassing 47 pancreatic ductal adenocarcinoma (PDAC), 5 cholangiocarcinoma, 1 Intraductal Papillary Mucinous Neoplasm (IPMN), 1 pancreatitis and 1 pancreatitis-Pancreatic Intraepithelial Neoplasia (PanIN) tissue. Pancreatitis, PanIN, and IPMN are seen as early events predecessing PDAC. An equiproportional pool of 5 PDAC cell lines (PANC1, SUIT-2, CFPAC-1, HPAC, MIAPACA2) is also taken along.