Hypoxia augments human embryonic stem cell self-renewal via hypoxia-inducible factor 2 (HIF2) activated OCT4 (POU5F1) transcription. Hypoxia also increases the efficiency of reprogramming differentiated cells to a pluripotent-like state. Combined, these findings suggest that low oxygen (O2) tension would impair the purposeful differentiation of pluripotent stem cells. Here, we show that low O2 tension and HIF activity instead promotes appropriate hESC differentiation. Through gain and loss of function studies, we implicate O2 tension as a modifier of a key cell fate decision, namely whether neural progenitors differentiate towards neurons or glia. Furthermore, our data show that even transient changes in O2 concentration can affect cell fate through HIF by regulating the activity of MYC, a regulator of LIN28/let-7 that is critical for fate decisions in the neural lineage. We also identify key small molecules that can take advantage of this pathway to quickly and efficiently promote the development of mature cell types.
Defining the role of oxygen tension in human neural progenitor fate.
Specimen part
View SamplesThe goal of this work was to identify all estrogen receptor beta target genes using RNA sequencing in MDA-MB-468 triple negative breast cancer cells engineered with inducible expression of full length estrogen receptor beta. Overall design: MDA-MB-468 breast cancer cells with inducible ERb expression (MDA-468-ERb cells) were treated in triplicate with vehicle (control, no ERb) or doxycycline (plus ERb) for 48 hr prior to treatment with 0.1% DMSO vehicle or 10 nM 17b-estradiol for 4 hr.
Research resource: global identification of estrogen receptor β target genes in triple negative breast cancer cells.
No sample metadata fields
View SamplesIncreased ploidy is common in tumors but treatments for tumors with excess chromosome sets are not available. Here, we characterize high-ploidy breast cancers and identify potential anticancer compounds selective for the high-ploidy state. Among 354 human breast cancers, 10% have mean chromosome copy number exceeding 3, and this is most common in triple negative and HER2-positive types. Women with high-ploidy breast cancers have higher risk of recurrence and death in two patient cohorts, demonstrating that it represents an important group for improved treatment. Because high-ploidy cancers are aneuploid, rather than triploid or tetraploid, we devised a two-step screen to identify selective compounds. The screen was designed to assure both external validity on diverse karyotypic backgrounds and specificity for high-ploidy cell types. This screen identified novel therapies specific to high-ploidy cells. First, we discovered 8-azaguanine, an antimetabolite that is activated by hypoxanthine phosphoribosyltransferase (HPRT), suggesting an elevated gene-dosage of HPRT in high-ploidy tumors can control sensitivity to this drug. Second, we discovered a novel compound, 2,3-Diphenylbenzo[g]quinoxaline-5,10-dione (DPBQ). DPBQ activates p53 and triggers apoptosis in a polyploid-specific manner, but does not inhibit topoisomerase or bind DNA. Mechanistic analysis demonstrates that DPBQ elicits a hypoxia gene signature and its effect is replicated, in part, by enhancing oxidative stress. Structure-function analysis defines the core benzo[g]quinoxaline-5,10 dione as being necessary for the polyploid-specific effects of DPBQ. We conclude that polyploid breast cancers represent a high-risk subgroup and that DPBQ provides a functional core to develop polyploid-selective therapy.
Identification of Selective Lead Compounds for Treatment of High-Ploidy Breast Cancer.
Cell line
View SamplesA split-split-plot design with 144 experimental units (3 replications x 4 genotypes x 6 time points x 2 treatment types) was used to profile barley plants containing variants of Mla1 and Mla6 powdery mildew resistance genes in response to inoculation with the Blumeria graminis f. sp. hordei (Bgh) isolates 5874 (AvrMla1, AvrMla6). Barley leaves were harvested from inoculated and non-inoculated plants at 6 time points (0,8,16,20,24 and 32 hrs) after Bgh inoculation. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Rico Caldo. The equivalent experiment is BB10 at PLEXdb.]
Blufensin1 negatively impacts basal defense in response to barley powdery mildew.
Specimen part, Time
View SamplesA large-scale parallel expression analysis was conducted to elucidate Mla-specified responses to powdery mildew infection using 22K Barley1 GeneChip probe arrays. Our goal was to identify genes differentially expressed in incompatible (resistant) vs. compatible (susceptible) and Mla-specified Rar1-dependent vs. -independent interactions. A split-split-plot design with 108 experimental units (3 replications x 2 isolates x 3 genotypes x 6 time points) was used to profile near-isogenic lines containing the Mla1, Mla6, and Mla13 resistance specificities in response to inoculation with the Blumeria graminis f. sp. hordei (Bgh) isolates 5874 (AvrMla1, AvrMla6) and K1 (AvrMla1, AvrMla13). ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Rico Caldo. The equivalent experiment is BB4 at PLEXdb.]
Interaction-dependent gene expression in Mla-specified response to barley powdery mildew.
Specimen part, Time
View SamplesTime-course expression profiles of Bgh challenged barley cultivar C.I. 16151 (harboring the Mla6 powdery mildew resistance allele) and its fast-neutron-derived "Bgh-induced tip cell death1" mutant, bcd1, were compared using the 22K Barley1 GeneChip. Planting, stage of seedlings, harvesting, and experimental design were part of a larger experiment described by Caldo et al. (2004). PLEXdb BB4. Experiment Design: C.I. 16151 (wildtype) and bcd1 (mutant) were planted in separate 20 x 30-cm flats using sterilized potting soil. Each experimental flat consisted of six rows of 15 seedlings, with rows randomly assigned to one of six harvest time points (0, 8, 16, 20, 24, and 32 hai). Seedlings grown to the 1st leaf stage with 2nd leaf unfolded were inoculated with a high density of fresh conidiospores (84 +/- 19 spores/mm2). Groups of flats were placed at 18C (8-hour darkness, 16-hour light) in separate controlled growth chambers corresponding to the Bgh isolates. Rows of plants were harvested at each assigned time points and snap frozen in liquid nitrogen. The entire experiment was repeated three times in a standard split-split-plot design with 72 experimental units (2 genotypes x 2 pathogen isolates x 6 time points x 3 replications). Treatment Description: The samples constituted pairwise combinations of the the cultivar C.I. 16151(containing the Mla6 resistance allele), and its fast-neutron-derived "Bgh-induced tip cell death1" mutant, bcd1 with the two Bgh (Blumeria graminis f. sp. hordei) isolates, 5874 (AvrMla6, AvrMla1) and K1 (AvrMla13, AvrMla1). For each replication, individual genotypes were planted in separate 20 x 30 cm flats using sterilized potting soil. Each experimental flat consisted of six rows of 15 seedlings, with rows randomly assigned to one of six harvest times (0, 8, 16, 20, 24, and 32 hai). Seedlings were grown to the 2nd-leaf stage with 1st leaf unfolded, and inoculation was performed at 4 PM Central Standard Time by tipping the flats at 45oC and dusting the plants with a high density of fresh conidiospores [84 +/- 19 spores/mm2]. This procedure was repeated from the opposite angle to ensure that a high proportion of the cells are in contact with the fungus. This conidial density per unit leaf area routinely results in greater than 50% of epidermal cells that are successfully infected. Groups of flats were placed at 18oC (8 hours darkness, 16 hours light, 8 hours darkness) in separate controlled growth chambers corresponding to the Bgh isolate. Rows of plants were harvested at their assigned harvest times and flash-frozen in liquid nitrogen. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Roger P Wise. The equivalent experiment is BB46 at PLEXdb.]
Interaction-dependent gene expression in Mla-specified response to barley powdery mildew.
Age, Specimen part, Time
View SamplesBarley stripe mosaic virus-induced gene silencing (BSMV-VIGS) was used to identify significant new genes in the regulation of host innate immunity. This experiment was designed to uncover significant changes in Bln1 (Contig12219_at)-silenced plants relative to empty vector and buffer treated controls. Five independent biological replications of a split-plot experimental design were conducted with replications as blocks, treatment with Blumeria graminis f. sp. hordei (Bgh) as the whole-plot factor, and all combinations of genotype (Mla13 and Mla9) and VIGS treatment [Buffer control (mock), BSMV:00 (empty vector), and BSMV:Bln1248] as the split-plot factor for a total of 60 GeneChip hybridizations. Ten seedlings were used as a split-plot experimental unit for each combination of replication, Bgh treatment, genotype, and VIGS treatment. Plants were grown in a controlled 20C glasshouse prior to VIGS treatment. Twelve days after VIGS treatment, half of the plants in each replication were challenged with the compatible Bgh isolate 5874. Top halves of 5 of the 10 seedling third leaves (about 10 cm) from each split-plot experimental unit were harvested into liquid N2 at 32 hours after inoculation (HAI) - the timepoint with the highest differential Bln1 transcript accumulation (Meng et al. 2009), and after initial establishment of the perihaustorial interface (Caldo et al. 2004). The remaining 5 leaves were used to record infection phenotype 7 days later. RNA was isolated for GeneChip hybridization from the 32-HAI samples. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Yan Meng. The equivalent experiment is BB101 at PLEXdb.]
Blufensin1 negatively impacts basal defense in response to barley powdery mildew.
Age, Specimen part
View SamplesMethylene diphenyl diisocyanate is a chemical known to cause asthma. The present study uses mice to investigate exposure-induced changes in lung gene expression and effects of a chloride channel inhibitor
Analysis of Lung Gene Expression Reveals a Role for Cl<sup>-</sup> Channels in Diisocyanate-induced Airway Eosinophilia in a Mouse Model of Asthma Pathology.
Sex
View SamplesA parallel expression profiling of wild-type and loss-of-function mutants of Mla6 and Mla1 powdery mildew resistance alleles was conducted using Barley1 GeneChip. Barley plants were inoculated with powdery mildew isolate 5874 and first leaves were harvested at 6 time points after pathogen inoculation. This experiment was conducted in split-split-plot experimental design with 3 replications.
Blufensin1 negatively impacts basal defense in response to barley powdery mildew.
Age, Specimen part, Time
View SamplesA large-scale parallel expression analysis was conducted to elucidate Mla-specified responses to powdery mildew infection using 22K Barley1 GeneChip probe arrays. Our goal was to identify genes differentially expressed in incompatible (resistant) vs. compatible (susceptible) and Mla-specified Rar1-dependent vs. -independent interactions. A split-split-plot design with 108 experimental units (3 replications x 2 isolates x 3 genotypes x 6 time points) was used to profile near-isogenic lines containing the Mla1, Mla6, and Mla13 resistance specificities in response to inoculation with the Blumeria graminis f. sp. hordei (Bgh) isolates 5874 (AvrMla1, AvrMla6) and K1 (AvrMla1, AvrMla13).
Interaction-dependent gene expression in Mla-specified response to barley powdery mildew.
Age, Specimen part, Disease, Disease stage, Cell line, Time
View Samples