Project description:We performed high numbers of replicates of CUT&RUN LoV-U against H3K4me3, β-catenin, and the negative control IgG in human colorectal cancer HCT116 cells over two independent rounds of experiments to discover the complete set of binding events.
Project description:In our attempts to profile different regulators of the WNT/b-catenin transcriptional complex, CUT&RUN failed to produce consistent binding patterns of the non-DNA-binding b-catenin. We developed a modified CUT&RUN protocol, which we refer to as LoV-U (Low Volume and Urea), that enables the generation of robust and reproducible b-catenin binding profiles. CUT&RUN-LoV-U can profile all classes of chromatin regulators tested, as shown by datasets targeting the TCF/LEF transcription factors and various histone modifications. CUT&RUN-LoV-U uncovers direct WNT/β-catenin target genes in human cells, as well as in ex vivo cells isolated from developing mouse tissue.
Project description:The Wnt/β-catenin signaling pathway plays crucial roles in nearly all parts of embryonic development and adult stem cell homeostasis. Its aberrant activation has been linked to many diseases such as developmental irregularities and various severe forms of cancer, with colorectal cancer (CRC) as a prime example. While much work has been dedicated to uncovering effective therapeutics to block oncogenic Wnt signaling, such interventions have not proven trivial because of the broad activity of Wnt throughout the adult body and the difficulty in finding suitable molecular targets. We have previously identified the developmental transcription factor TBX3 as a participant of the Wnt-mediated transcriptional regulation. Here we examine the genome-wide binding pattern of TBX3 in the human CRC cells lines HCT116 (25 replicates), DLD1 (2 replicates) and SW620 (2 replicates), by employing CUT&RUN (C&R) with Low-Volume and Urea (LoV-U; Zambanini et al., 2022).
Project description:MBD2 genome-binding landscape was assessed by CUT&RUN-sequencing in differentiating C2C12 cells. H3K4Me3 CUT&RUN-sequencing was performed as a positive control. Negative control experiment was also performed using a rabbit isotype control monoclonal IgG.
Project description:HCT116 colorectal cancer cells were treated with a novel inhibitor of ß-catenin/BCL9 interaction and evaluated for transcriptional changes using RNA-seq.
Project description:Wnt/β-catenin signaling is a highly organized biochemical cascade that triggers a gene expression program in the signal-receiving cell. The Wnt/β-catenin-driven transcriptional response is involved in virtually all cellular processes during development, homeostasis, and its deregulation causes human disease. However, outstanding questions remain unanswered. Here, we combined RNA sequencing with CUT&RUN-LoV-U against β-catenin to assess the correlation between β-catenin recruitment to target loci and its effect on target gene expression. To this end, we performed a bulk RNA sequencing analysis on human embryonic stem cells (hESCs) treated with the the GSK3 inhibitor/Wnt activator CHIR99021 (10 mM) for 3 days, and compared them to untreated hESCs. We then correlated the observed gene expression changes with β-catenin binding events identified from a separate experiment (see “Related Accession Number”). We observed that β-catenin binding is associated with both activation and repression of cell-specific gene expression programs, underscoring how Wnt/b-catenin drives complex cell behaviors.
Project description:Activating transcription factor 4 (ATF4) is activated during cellular stress through a pathway called the integrated stress response (ISR). We had previously reported that the splicing inhibitor isoginkgetin (IGG) activates ATF4 and ATF4-dependent transcripts. To determine the role of ATF4 in the transcriptional response to IGG, we used tandem CRISPR cas9 gene editing to create an ATF4 deficient HCT116 (colon cancer) cell line. We completed RNA sequencing on HCT116 parental and HCT116 ATF4 deficient cells treated with IGG, and thapsigargin (Tg), a positive control for ATF4 activation. We found that IGG led to the differential expression of 76 transcripts, and 58 of these were dependent on ATF4. Tg led to a far more robust transcriptional response, which appeared to be less ATF4 dependent.
Project description:Purpose: WNT signaling activation in colorectal cancers (CRCs) occurs mainly through APC inactivation or, more uncommonly, β-catenin activation. Both processes promote β-catenin nuclear accumulation, which transcriptionally up-regulates epithelial-to-mesenchymal transition (EMT)-related genes. Experimental Design: We investigated β-catenin localization, downstream gene expression, and phenotypic alterations in HCT116 cells containing a wild-type (HCT116-WT) or mutant β-catenin allele (HCT116-MT), or parental cells with both WT and mutant alleles (HCT116-P). We then analyzed β-catenin localization and associated phenotypes in CRC tissues. Results: Wild-type β-catenin mainly localized at the cell membrane, whereas mutant showed predominantly nuclear localization; membranous, cytoplasmic, and nuclear localization was observed in HCT116-P cells. Microarray analysis revealed significant down-regulation of Claudin-7 and E-cadherin in HCT116-MT vs. HCT116-WT cells. Claudin-7 was also down-regulated in HCT116-P vs. HCT116-WT cells, although E-cadherin expression was unaffected. Altered expression of cell-cell junction-related molecules led to tight junction (TJ) impairment in HCT116-P, and dual loss of TJs and adherens junctions (AJs) in HCT116-MT. TJ loss increased migration and invasion activities of HCT116-WT, whereas AJ loss was required to further up-regulate these activities in HCT116-P. Immunohistochemistry analysis of 101 stage III CRC tissues revealed high nuclear β-catenin expression (≥30% of tumor cells) in 15 (14.9%) samples, low nuclear expression (1-29%) in 53 (52.5%) samples, and undetectable nuclear expression in 33 (32.6%) samples, with a trend toward more frequent down-regulation of Claudin-7 and E-cadherin, and increased metastasis in CRCs with high vs. low nuclear β-catenin. Conclusions: β-catenin activation and nuclear translocation induce EMT progression by modifying cell-cell junctions, and are associated with aggressive behaviors of CRCs.
Project description:CUT&RUN for IgG, H3K4me3 and HA-SPDEF in human PDA HPAF-II cells and CUT&RUN HA-Spdef in murine KPC 2D FC1245 cells We performed CUT&RUN assay in human and murine PDA cells to profile the direct binding of SPDEF to target genes.