The effect of Tumor Necrosis Factor Receptor 1 (TNFR1) loss on gene expression in beta-catenin-deprive colon cancer cells
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ABSTRACT: Human colon carcinoma cells SKCO1 were deprived of either beta-catenin alone or beta-catenin together with TNFR1 and changes in mRNA levels were examined before and after TNFR1 ablation
Project description:Human colon carcinoma cells SKCO1 were deprived of either beta-catenin alone or beta-catenin together with TNFR1 and changes in mRNA levels were examined before and after TNFR1 ablation SKCO1 cells were transfected with either beta-catenin-specific siRNA alone or beta-catenin-specific siRNA together with a TNFR1-specific siRNA and changes in mRNA levels were examined before and after TNFR1 ablation
Project description:We have compared mRNA expression in full-thickness mouse colon between wildtype mice and mice with a genetic deletion in tumor necrosis factor receptor 1 (TNFR1, encoded by the Tnfrsf1a gene). This experiment was motivated by our observation that Il10-/- Tnfr1-/- double-knockout mice develop very-early-onset colitis at the time of weaning, significantly earlier than disease onset in Il10-/- single-knockout mice. This suggests that TNFR1 mediates protection from colitis. To understand these protective mechanisms at the transcript level in a non-inflammatory context, we performed transcriptome profiling (mRNA-Seq) on colons from 12-week-old Tnfr1-/- mice, which do not develop colitis, and wildtype littermates. These experiments revealed that an estimated 510 transcripts were upregulated and 377 downregulated in colonic tissue of Tnfr1-/- mice. We aggregated the transcript information to calculate gene expression and performed gene set enrichment analysis to identify signaling pathways altered in Tnfr1-/- mice. When queried against a high-confidence set of 50 signaling pathways, the Tnfr1-/- gene expression profile was associated with reduced mitosis and increased glycolysis, transforming growth factor beta signaling, DNA repair, and reactive oxygen species signaling. Gene ontological analysis classified some of the differentially expressed genes into cytokines, junctional proteins, and transcription factors, but within these groups there was no consensus on the direction of regulation. We also examined how differentially expressed transcripts (called the TNFR1-regulated transcriptome) compared to differentially expressed colonic transcripts from previously collected Tnfr2-/- animals (or the TNFR2-regulated transcriptome, available at the NCBI Gene Expression Omnibus under the accession GSE65408). The raw data were re-analyzed with the current pipeline to enable comparison. There was almost no correlation between TNFR1- and TNFR2-regulated transcripts. Only 30 (~3%) TNFR1-regulated transcripts were also TNFR2-regulated transcripts, and ~4% of the TNFR2-regulated genes were also TNFR1-regulated genes. Of the few co-regulated transcripts, there was a significant negative correlation in their direction of regulation in Tnfr1-/- versus Tnfr2-/- colons. Collectively these results indicate that TNFR1 and TNFR2 have mostly different and opposing effects on gene expression in the mouse colon. MANUSCRIPT ABSTRACT: BACKGROUND & AIMS: Very-early-onset inflammatory bowel disease (VEO-IBD) is a devastating disease beginning in early childhood, refractory to anti-tumor necrosis factor (anti-TNF) therapies, and associated with mutations in the interleukin 10 (IL-10) pathway. Contrary to mainstream clinical practice, cellular and animal studies have shown beneficial roles of TNF signaling in colitis, but how these roles are encoded through TNF’s receptors remains unknown. Here we examined the role of TNF receptor 1 (TNFR1, or p55) in modulating the onset and severity of colitis in the interleukin 10 (IL-10)-deficient mouse model. METHODS: Colitis severity was compared between Il10-/- Tnfr1-/- and Il10-/-- littermate mice at 2-12 weeks of age. To assess dysbiosis as a potential pathogenic mechanism, Il10-/- Tnfr1-/- mice were treated with neomycin and metronidazole and their cecal contents analyzed by 16S rRNA sequencing. Gene expression, barrier function, and epithelial proliferation and apoptosis were examined in adult colitis-free Tnfr1-/- wildtype littermates. RESULTS: In contrast to relatively healthy Il10-/- mice, Il10-/- Tnfr1-/- mice developed severe, antibiotic-treatable colitis shortly after weaning. Microbiotal composition was similar between Il10‑/- Tnfr1-/- mice and Il10-/- littermate controls. Tnfr1-/- mice expressed transcripts associated with reactive oxygen species and DNA repair pathways. Tnfr1-/- mice exhibited focal areas of crypt branching, higher colonic epithelial permeability, and hallmarks of DNA damage. CONCLUSIONS: TNFR1 promotes epithelial homeostasis and regulates commensal exposure. The lack of TNFR1 accelerates the onset and severity of IBD in the absence of tolerogenic signaling (i.e., lack of IL-10). Il10-/- Tnfr1-/- mice may serve as a valuable model of very-early-onset IBD (VEO-IBD).
Project description:Deregulation of the canonical Wnt/beta-catenin pathway is one of the earliest events in the pathogenesis of colon cancer. Mutations in APC or CTNNB1 are frequent in colon cancer and cause aberrant stabilization of beta-catenin, which activates Wnt target genes by binding to chromatin via TCF/LEF transcription factors. In a comprehensive study, we conducted an integrative analysis of genome-wide chromatin occupancy of beta-catenin by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) along with gene expression profiling changes resulting from RNAi-mediated knockdown of beta-catenin in colon cancer cells. This experiment series represents the gene expression changes detected by microarray as a result of CTNNB1 perturbation. SW480 cells were transfected with control and beta-catenin siRNAs. Twenty-four hours after transfection, RNA was extracted from the cells using the RNeasy kit (Qiagen, Valencia, CA) and genome-wide cDNA microarray expression analysis was performed. The data reported here are the microarray data as processed by the standard Rosetta Resolver(R) ratio method for Agilent microarrays.
Project description:Deregulation of the canonical Wnt/beta-catenin pathway is one of the earliest events in the pathogenesis of colon cancer. Mutations in APC or CTNNB1 are frequent in colon cancer and cause aberrant stabilization of beta-catenin, which activates Wnt target genes by binding to chromatin via TCF/LEF transcription factors. In a comprehensive study, we conducted an integrative analysis of genome-wide chromatin occupancy of beta-catenin by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) along with gene expression profiling changes resulting from RNAi-mediated knockdown of beta-catenin in colon cancer cells. This experiment series represents the gene expression changes detected by microarray as a result of CTNNB1 perturbation.
Project description:Deregulation of canonical Wnt/beta-catenin pathway is one of the earliest events in the pathogenesis of colon cancer. Mutations in APC or CTNNB1 (beta-catenin gene) are highly frequent in colon cancer and cause aberrant stabilization of b-catenin, which activates the transcription of Wnt target genes by binding to chromatin via the TCF/LEF transcription factors. Here we report an integrative analysis of genome-wide chromatin occupancy of b-catenin by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) and gene expression profiling by microarray analysis upon RNAi-mediated knockdown of beta-catenin in colon cancer cells (GSE53656). Immunoprecipitated samples from human colon cancer SW480 cells with antibodies against beta-catenin and control IgG respectively were used for ChIP-seq experiments.
Project description:We established a model system in human DLD1 colon cancer cells to study the transcriptional crosstalk between FOXO3A and beta-Catenin. Thereby, translocation to the nucleus of a AKT-insensitive mutant (T32A, S253A, S315A) of human FOXO3A fused to the ligand binding domain of human estrogen receptor can be induced by exposure to 4-hydroxy-tamoxifen. Furthermore, expression of a stable mutant (S33Y) of human beta-catenin is doxycycline inducible. Addition of those drugs separately or in combination allows identification of common or excusive target gene sets.
Project description:To validate the suitability of two commonly used colorectal cancer cell lines, DLD1 and SW480, as model systems to study colorectal carcinogenesis, we treated these cell lines with beta-catenin siRNA and identified beta-catenin target genes using DNA microarrays. The list of identified target genes was compared to previously published beta-catenin target genes found in the PubMed and the GEO databases. Based on the large number of beta-catenin target genes found to be similarly regulated in DLD1, SW480 and LS174T as well as the large overlap with confirmed β-catenin target genes, we conclude that DLD1 and SW480 colon carcinoma cell lines are suitable model systems to study beta-catenin regulated genes and signaling pathways 12 arrays (2 cell lines, 2 treatments, 3 biological replicates)
Project description:Deregulation of canonical Wnt/beta-catenin pathway is one of the earliest events in the pathogenesis of colon cancer. Mutations in APC or CTNNB1 (beta-catenin gene) are highly frequent in colon cancer and cause aberrant stabilization of b-catenin, which activates the transcription of Wnt target genes by binding to chromatin via the TCF/LEF transcription factors. Here we report an integrative analysis of genome-wide chromatin occupancy of b-catenin by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) and gene expression profiling by microarray analysis upon RNAi-mediated knockdown of beta-catenin in colon cancer cells (GSE53656).
Project description:To validate the suitability of two commonly used colorectal cancer cell lines, DLD1 and SW480, as model systems to study colorectal carcinogenesis, we treated these cell lines with β-catenin siRNA and identified β-catenin target genes using DNA microarrays. The list of identified target genes was compared to previously published β-catenin target genes found in the PubMed and the GEO databases. Based on the large number of β-catenin target genes found to be similarly regulated in DLD1, SW480 and LS174T as well as the large overlap with confirmed β-catenin target genes, we conclude that DLD1 and SW480 colon carcinoma cell lines are suitable model systems to study β-catenin regulated genes and signaling pathways