RNA-Seq analysis of primary AML specimens exposed to AhR modulating agents
Ontology highlight
ABSTRACT: The goal of the study was to identify genes that are directly or indirectly coregulated by the AhR pathway in primary human AML cells. Patient AML cells were treated for 16 hours with the two indirubin derivatives 6-bromoindirubin-3'oxime (BIO), 1-Methyl-6-bromoindirubin-3'oxime (MeBIO), the AHR-antagonist SR1 (StemReginin1), combinations of BIO+SR1 and MeBIO+SR1 or DMSO alone at indicated concentrations prior to RNA extraction for sequencing.
Project description:The goal of the study was to identify genes that are directly or indirectly coregulated by the AhR pathway in primary human AML cells. Patient AML cells were treated for 16 hours with the two indirubin derivatives 6-bromoindirubin-3'oxime (BIO), 1-Methyl-6-bromoindirubin-3'oxime (MeBIO), the AHR-antagonist SR1 (StemReginin1), combinations of BIO+SR1 and MeBIO+SR1 or DMSO alone at indicated concentrations prior to RNA extraction for sequencing. RNA-Seq performed on 5 primary AML samples fresh (t0) and after exposure to AhR-agonists (2), -antagonist (1), and DMSO Contributor: Leucegene Project, IRIC
Project description:Indole-3-pyruvate (I3P), an endogenous metabolite derived from tryptophan by gut microbiota and IL4I1 enzyme in humans can potentially activate the transcriptional activity of the Aryl Hydrocarbon receptor. Here we test this by stimulating AHR proficient U-87MG cells with I3P alone or in combination with the AHR antagonist SR1.
Project description:To examine the changes in RNA expression profile under AhR antagonist treatment in human hematopoietic stem progenitor cells (HSPCs), CD34+cells were isolated from umbilical cord blood (UCB) unit. CD34+cells were cultured with two different AhR antagonists CH223191 and StemRegenin1 (SR1) ex vivo for 7 days. cultured cells were used to perform RNA sequencing and analyze the changes in RNA expression profile by treatment.
Project description:Targeting the estrogen signaling pathway has proved to be of great value in the treatment of human breast cancer. Tamoxifen, a selective estrogen receptor modulator (SERM), is the most widely used antiestrogen. However, only 40-50% of patients with estrogen receptor (ER) positive breast cancer benefit from tamoxifen treatment and 30-50% acquire resistance and the disease progresses. Continuous treatment with conventional therapy may contribute to cancer progression in recurring cancers through the accumulation of drug resistant cancer progenitors. We found that MCF7 tamoxifen-resistant (TAM-R) cells possess a significantly higher proportion of cancer progenitor cells than tamoxifen-sensitive MCF7 cells. Our results indicate that the chemokine receptor CXCR4 plays an important role in the maintenance of cancer progenitors in a tamoxifen-resistant cell line and downregulation of CXCR4 signaling by small molecule antagonists specifically inhibits growth of a stem-like cell population in tamoxifen-resistant tumors both in vitro and in vivo. Whole genome gene expression analysis revealed aryl hydrocarbon receptor (AhR) signaling as one of the top networks that is differentially regulated in MCF7(TAM-R) xenograft tumors treated with the CXCR4 antagonist AMD3100 as compared to MCF7 tumors. Further, small molecule antagonists of AhR signaling specifically inhibit the progenitor population in MCF7(TAM-R) cells suggesting that the aryl hydrocarbon receptor could be a putative target for the treatment of tamoxifen-resistant breast cancers. Introduction transplants remains limited by the ability to expand these cells ex vivo. An unbiased screen with primary human HSCs identified a purine derivative, StemRegenin 1 (SR1), that promotes the ex vivo expansion of CD34+ cells. Culture of HSCs with SR1 led to a 50-fold increase in cells expressing CD34 and a 17-fold increase in cells that retain the ability to engraft immunodeficient mice. Mechanistic studies show that SR1 acts by antagonizing the aryl hydrocarbon receptor (AHR). The identification of SR1 and AHR modulation as a means to induce ex vivo HSC expansion should facilitate the clinical use of HSC therapy. Tamoxifen resistant or sensitive xenografts; mice treated with estrogen and/or CXCR4 modulators
Project description:Targeting the estrogen signaling pathway has proved to be of great value in the treatment of human breast cancer. Tamoxifen, a selective estrogen receptor modulator (SERM), is the most widely used antiestrogen. However, only 40-50% of patients with estrogen receptor (ER) positive breast cancer benefit from tamoxifen treatment and 30-50% acquire resistance and the disease progresses. Continuous treatment with conventional therapy may contribute to cancer progression in recurring cancers through the accumulation of drug resistant cancer progenitors. We found that MCF7 tamoxifen-resistant (TAM-R) cells possess a significantly higher proportion of cancer progenitor cells than tamoxifen-sensitive MCF7 cells. Our results indicate that the chemokine receptor CXCR4 plays an important role in the maintenance of cancer progenitors in a tamoxifen-resistant cell line and downregulation of CXCR4 signaling by small molecule antagonists specifically inhibits growth of a stem-like cell population in tamoxifen-resistant tumors both in vitro and in vivo. Whole genome gene expression analysis revealed aryl hydrocarbon receptor (AhR) signaling as one of the top networks that is differentially regulated in MCF7(TAM-R) xenograft tumors treated with the CXCR4 antagonist AMD3100 as compared to MCF7 tumors. Further, small molecule antagonists of AhR signaling specifically inhibit the progenitor population in MCF7(TAM-R) cells suggesting that the aryl hydrocarbon receptor could be a putative target for the treatment of tamoxifen-resistant breast cancers. Introduction transplants remains limited by the ability to expand these cells ex vivo. An unbiased screen with primary human HSCs identified a purine derivative, StemRegenin 1 (SR1), that promotes the ex vivo expansion of CD34+ cells. Culture of HSCs with SR1 led to a 50-fold increase in cells expressing CD34 and a 17-fold increase in cells that retain the ability to engraft immunodeficient mice. Mechanistic studies show that SR1 acts by antagonizing the aryl hydrocarbon receptor (AHR). The identification of SR1 and AHR modulation as a means to induce ex vivo HSC expansion should facilitate the clinical use of HSC therapy.
Project description:Although practiced clinically for more than 40 years, the use of hematopoietic stem cell (HSC) transplants remains limited by the ability to expand these cells ex vivo. An unbiased screen with primary human HSCs identified a purine derivative, StemRegenin 1 (SR1), that promotes the ex vivo expansion of CD34+ cells. Culture of HSCs with SR1 led to a 50-fold increase in cells expressing CD34 and a 17-fold increase in cells that retain the ability to engraft immunodeficient mice. Mechanistic studies show that SR1 acts by antagonizing the aryl hydrocarbon receptor (AHR). The identification of SR1 and AHR modulation as a means to induce ex vivo HSC expansion should facilitate the clinical use of HSC therapy. LGC006, a less potent SR1 analog, was also examined. KEYWORDS: two compounds, multiple doses, one time point two compounds, multiple doses, one time point
Project description:Although practiced clinically for more than 40 years, the use of hematopoietic stem cell (HSC) transplants remains limited by the ability to expand these cells ex vivo. An unbiased screen with primary human HSCs identified a purine derivative, StemRegenin 1 (SR1), that promotes the ex vivo expansion of CD34+ cells. Culture of HSCs with SR1 led to a 50-fold increase in cells expressing CD34 and a 17-fold increase in cells that retain the ability to engraft immunodeficient mice. Mechanistic studies show that SR1 acts by antagonizing the aryl hydrocarbon receptor (AHR). The identification of SR1 and AHR modulation as a means to induce ex vivo HSC expansion should facilitate the clinical use of HSC therapy. LGC006, a less potent SR1 analog, was also examined. KEYWORDS: two compounds, multiple doses, one time point
Project description:Background: Estrogen receptor (ERα) and aryl hydrocarbon receptor (AHR) are two nuclear receptors involved in regulating gene expression. ERα and AHR are regulated by estradiol(E2) and TCDD respectively. They are also regulated by dietary ligands including 3,3´diindolylmethane (DIM) and resveratrol (RES). DIM is an ERα and AHR agonist, while RES is an ERα agonist and AHR antagonist. Few studies have investigated the impact of RES and DIM on ERα and AHR signaling at a genome-wide level. This study assessed ERα and AHR binding and associated gene expression changes after treatment of MCF-7 human breast cancer cells with DIM, RES, E2, TCDD, and E2+TCDD for 1 hour and 6 hours before ChIP and RNA sequencing respectively. Results: 88% and 86% of the ERα bound sites after RES and DIM overlapped with E2 ERα sites. RES and DIM resulted in 577 and 446 differentially expressed genes (DEGs) respectively compared to 866 after E2. 68% and 62.3% of the DEGs after RES and DIM were closest to an ERα binding site. Motif analysis indicated enrichment for AHRE motif among DIM ERα sites but not among E2 or RES ERα sites. Both DIM and E2+TCDD resulted in greater genome wide binding of AHR than TCDD. DIM and E2+TCDD resulted in 10546 and 8904 AHR and ERα co-occupied sites respectively. While co-occupied sites for both enriched for the AHR and ERE motif among others, DIM mediated co-occupied sites enriched for Tcfcp2l1, Tgif1, Gata3 motifs while E2+TCDD mediated ones enriched for the NF1 and Ppara motifs. Overlap of coregulated DEGs after DIM and E2+TCDD indicated 123 were the same among both with 81 and 85 unique coregulated DEGs respectively. Enrichment analysis indicated that more enrichment terms were different than similar for coregulated genes after E2+TCDD and DIM. Conclusions: AHR activation is responsible for DIM mediated reduced regulation of gene expression by ERα relative to E2 and only a subset of the DEG’s after DIM and RES are ERα targets indicating future studies into other transcription factors regulated by DIM and RES are needed for insights into the regulation of gene expression by these ligands.
Project description:To study the effect of blockade of canonical aryl hydrocarbon receptor (AHR) pathway in human endothelial cells, we treated human umbilical vein endothelial cells (HUVECs) with a canonical AHR inhibitor, Stemreginin 1 (SR1) and performed bulk RNAseq analysis.