Project description:Alterations that perturb differentiation and cell state transitions can lead to defects in development, function and the genesis of cancer. Studying cellular plasticity at high resolution and in real time has proven difficult using existing methods. Here, we use a quantitative approach to gain insights into cell state dynamics of normal mammary epithelial cells (MECs) and validate the model's predictions in vivo. In the absence of Slug/SNAI2, basal mammary progenitor cells transition into a luminal differentiation state, while luminal progenitor cells proliferate and expand; these changes result in abnormal mammary architecture and defects in tissue function. Loss of Slug also disrupts cellular plasticity leading to defects in tissue regeneration and the initiation of cancer. Mechanistically, Slug promotes cellular plasticity by recruiting the chromatin modifier, LSD1 (lysine specific demethylase 1), to promoters of lineage specific genes to represses transcription. Together, these finding demonstrate that Slug is necessary for cellular adaptation during tissue development and regeneration, and that transitioning back into a more primitive stem-like state is a prerequisite for tumor initiation. reference x sample
Project description:Alterations that perturb differentiation and cell state transitions can lead to defects in development, function and the genesis of cancer. Studying cellular plasticity at high resolution and in real time has proven difficult using existing methods. Here, we use a quantitative approach to gain insights into cell state dynamics of normal mammary epithelial cells (MECs) and validate the model's predictions in vivo. In the absence of Slug/SNAI2, basal mammary progenitor cells transition into a luminal differentiation state, while luminal progenitor cells proliferate and expand; these changes result in abnormal mammary architecture and defects in tissue function. Loss of Slug also disrupts cellular plasticity leading to defects in tissue regeneration and the initiation of cancer. Mechanistically, Slug promotes cellular plasticity by recruiting the chromatin modifier, LSD1 (lysine specific demethylase 1), to promoters of lineage specific genes to represses transcription. Together, these finding demonstrate that Slug is necessary for cellular adaptation during tissue development and regeneration, and that transitioning back into a more primitive stem-like state is a prerequisite for tumor initiation.
Project description:Temporal expression profiling was utilized to define transcriptional regulatory pathways in vivo in a mouse muscle regeneration model. Potential downstream targets of MyoD were identified by temporal expression, promoter data base mining, and gel shift assays; Slug and calpain 6 were identified as novel MyoD targets. Slug, a member of the snail/slug family of zinc finger transcriptional repressors critical for mesoderm/ectoderm development, was further shown to be a downstream target by using promoter/reporter constructs and demonstration of defective muscle regeneration in Slug null mice.
Project description:Cellular plasticity and transitional cellular states are crucial for tissue regeneration across multiple organs. In the pancreas, oncogenic Kras hijacks this program, acting on tissue-specific enhancers to prevent the resolution of acinar-to-ductal metaplasia (ADM) and lock regeneration into a pro-inflammatory state that progresses to cancer. Enhancer transcription, an early event during cellular state transitions, can generate stable enhancer-associated long noncoding RNAs (lncRNAs) positioned near key transcription factors and chromatin contact boundaries, often enriched for disease-associated variants. While enhancer-associated lncRNAs have been implicated in transcriptional regulation and genome organization, their role in pancreas regeneration and cancer initiation has remained unexplored. In this study, we identified epithelial long noncoding RNAs (lncRNAs) and their target genes in PDAC precursor lesion formation. We demonstrate that LINC00673, expressed from a Sox9-associated super-enhancer during pancreatic development, is reactivated in PDAC. Conditional deletion of LINC00673 in the murine pancreatic epithelium accelerates resolution of ADM and significantly impairs PDAC initiation. Furthermore, we highlight a previously unrecognized role of transcribed super-enhancers in facilitating long-range gene regulation and genome organization during pancreatic cancer initiation. Our study identifies a critical function of LINC00673 in regulating both cell-autonomous and non-cell-autonomous processes during pancreas regeneration and Kras-driven cancer initiation. These findings reveal a novel regulatory layer linking developmental enhancer activity to pancreatic disease progression and highlight new therapeutic opportunities targeting regenerative programs at the earliest stages of neoplastic transformation.
Project description:Temporal expression profiling was utilized to define transcriptional regulatory pathways in vivo in a mouse muscle regeneration model. Potential downstream targets of MyoD were identified by temporal expression, promoter data base mining, and gel shift assays; Slug and calpain 6 were identified as novel MyoD targets. Slug, a member of the snail/slug family of zinc finger transcriptional repressors critical for mesoderm/ectoderm development, was further shown to be a downstream target by using promoter/reporter constructs and demonstration of defective muscle regeneration in Slug null mice. Keywords: other
Project description:microRNA expression profiling of Stage I Lung Adenocarcinoma and non-tumor adjacent tissues. The Nanostring nCounter Human miRNA Expression Assay Kit version 1.6 (Nanostring, Seattle, WA) was used to obtain microRNA profiles of tumor and adjacent non-tumor tissues excised from Stage I Lung Adenocarcinoma patients. Total cellular RNA was extracted from tumor and matching adjacent non-tumor lung using miRNA Kit (QIAGEN), according to the manufacturer’s instructions, and 100 ng were used for hybridization to Nanostring nCounter Human miRNA Expression Assay Kit version 1.6 (Nanostring, Seattle, WA) following processing protocol recommended by the manufacturer.
Project description:As a rapid Stem11 scoring platform, a custom NanoString nCounter panel was designed. Alongside the Stem11 genes, the previously published LSC17 genes were included as an established transcriptional prognostic system for AML. For data normalization, seven housekeeping genes were further included from a previous custom NanoString nCounter panel. The full list of the 35 genes in our custom panel is provided in the manuscript.
Project description:Group A Streptococcus (GAS) encodes two paralogs of the Spx transcriptional regulator, SpxA1 and SpxA2, which interact with RNA polymerase to modulate virulence gene expression. SpxA2 is directly regulated by the LiaFSR three-component system in response to antimicrobial peptide stress. To define how SpxA2 influences CovR DNA occupancy genome-wide, we performed chromatin immunoprecipitation with exonuclease treatment (ChIP-exo) targeting CovR in wild-type MGAS10870 (emm3), an isogenic spxA2 deletion mutant (deltaSpxA2), and a LiaSQ146A constitutively active LiaS mutant used as a SpxA2 overexpression surrogate (SpxA2-OE). Differential binding analysis identified 439 sites with significantly altered CovR occupancy between wild-type and deltaSpxA2 (FDR < 0.05), with class-specific enrichment of CovR dimer and monomer binding motifs consistent with the two-class CovR binding model (Horstmann et al. 2023). These data contribute to a multi-omic analysis including RNA-seq, DIA proteomics, and NanoString nCounter that defines the regulatory roles of SpxA1 and SpxA2 in GAS pathogenesis.