Project description:Analysis of gene expression changes due to lack of AhR in NK cells. Cytokine activated NK cells upregulate expression of AhR and display homeostatic and functional defects. Goal of this study was to identify gene expression changes associated with NK cell activity.
Project description:To investigate the global genes regulated by AHR, high-throughput mRNA sequencing (RNA-Seq) was performed to compare the expression profile between DLD-1 cells transfected with control siRNA or AHR siRNA.
Project description:The aryl hydrocarbon receptor (AHR) and AHR nuclear translocator (ARNT) activated complex regulates genes in response to the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). AHR has also emerged as a potential therapeutic target for the treatment of human diseases and different cancers, including breast cancer. To better understand AHR and ARNT signaling in breast cancer cells, we used chromatin immunoprecipitation linked to high throughput sequencing to identify AHR- and ARNT-binding sites across the genome in TCDD treated MCF-7 cells. We identified 2,594 AHR-bound, 1,352 ARNT-bound and 882 high confidence AHR/ARNT co-bound regions. No significant differences in the genomic distribution of AHR and ARNT were observed. Approximately 60% of the co-bound regions contained at least one core AHRE, 5'-GCGTG-3'. AHR/ARNT peak density was the highest within 1 kb of transcription start sites (TSS); however, a number of AHR/ARNT co-bound regions were located as far as 100 kb from TSS. De novo motif discovery identified a symmetrical variation of the AHRE (5'-GTGCGTG-3'), as well as FOXA1 and SP1 binding motifs. Microarray analysis identified 104 TCDD responsive genes where 98 genes were up-regulated by TCDD. Of the 104 regulated genes, 69 (66.3%) were associated with an AHR- or ARNT-bound region within 100 kb of their TSS. Overall our study identified AHR/ARNT co-bound regions across the genome, revealed the importance but not absolute requirement for an AHRE in AHR/ARNT interactions with DNA, and identified a modified AHRE motif, thereby increasing our understanding of AHR/ARNT signaling pathway. Examination of genome-wide AHR and ARNT binding pattern in MCF-7
Project description:The aryl hydrocarbon receptor (AHR) and AHR nuclear translocator (ARNT) activated complex regulates genes in response to the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). AHR has also emerged as a potential therapeutic target for the treatment of human diseases and different cancers, including breast cancer. To better understand AHR and ARNT signaling in breast cancer cells, we used chromatin immunoprecipitation linked to high throughput sequencing to identify AHR- and ARNT-binding sites across the genome in TCDD treated MCF-7 cells. We identified 2,594 AHR-bound, 1,352 ARNT-bound and 882 high confidence AHR/ARNT co-bound regions. No significant differences in the genomic distribution of AHR and ARNT were observed. Approximately 60% of the co-bound regions contained at least one core AHRE, 5'-GCGTG-3'. AHR/ARNT peak density was the highest within 1 kb of transcription start sites (TSS); however, a number of AHR/ARNT co-bound regions were located as far as 100 kb from TSS. De novo motif discovery identified a symmetrical variation of the AHRE (5'-GTGCGTG-3'), as well as FOXA1 and SP1 binding motifs. Microarray analysis identified 104 TCDD responsive genes where 98 genes were up-regulated by TCDD. Of the 104 regulated genes, 69 (66.3%) were associated with an AHR- or ARNT-bound region within 100 kb of their TSS. Overall our study identified AHR/ARNT co-bound regions across the genome, revealed the importance but not absolute requirement for an AHRE in AHR/ARNT interactions with DNA, and identified a modified AHRE motif, thereby increasing our understanding of AHR/ARNT signaling pathway.
Project description:The transcriptional program of early embryonic development is tightly regulated by a set of well-defined transcription factors that suppress premature expression of differentiation genes and sustain the pluripotent identity. It is generally accepted that this program can be perturbed by environmental factors such as chemical pollutants, however the precise molecular mechanisms remain unknown. The Aryl Hydrocarbon Receptor (AHR) is a widely expressed nuclear receptor that senses environmental stimuli and modulates target gene expression. Here, we show that ectopic activation of AHR during early differentiation disrupts the differentiation program via the chromatin remodeling complex NuRD. The activated AHR/NuRD complex altered the expression of differentiation-specific genes that control the first two developmental decisions without affecting the pluripotency program. These findings identify a novel mechanism that allows environmental stimuli to disrupt embryonic development through AHR signaling.
Project description:Inhibitors directed towards PARP1 and PARP2 are approved agents for the treatment of BRCA-related cancers. Other members of the PARP family have also been implicated in cancer and are being assessed as therapeutic targets in cancer and other diseases. In fact, an inhibitor of PARP7 (RBN-2397) has now reached early-stage human clinical trials. Here, we performed a genome-wide CRISPR screen for genes that modify the response of cells to RBN-2397. We identify the polycyclic aromatic hydrocarbon receptor AHR and multiple components of the cohesin complex as determinants of resistance to this agent. Activators and inhibitors of AHR modulate the cellular response to PARP7 inhibition, suggesting potential combination therapy approaches.
Project description:We have generated transgenic mice expressing constitutively activated aryl hydrocarbon receptor (CA-AhR) to examine the biological consequences of AhR activation.. We used microarrays to identify genes that are regulated by AhR.