Organoid technology provides the possibility to culture human colon tissue and patient-derived colorectal cancers (CRC) while maintaining all functional and phenotypic characteristics. Labeling of human colon stem cells (CoSCs), especially in normal and benign tumor organoids, is challenging and therefore limits usability of multi-patient organoid libraries for CoSC research. Here, we developed STAR (STem cell Ascl2 Reporter), a minimal enhancer/promoter element that reports transcriptional activity of ASCL2, a master regulator of LGR5+ CoSC fate. Among others via lentiviral infection, STAR minigene labels stem cells in normal as well as in multiple engineered and patient-derived CRC organoids of different stage and genetic make-up. STAR revealed that stem cell driven differentiation hierarchies and the capacity of cell fate plasticity (de-differentiation) are present at all stages of human CRC development. The flexible and user-friendly nature of STAR applications in combination with organoid technology will facilitate basic research on human adult stem cell biology. Overall design: Cells from different colon organoid types were FACS sorted for stem STemness Ascl2 Reporter activity for transcriptome profiling by RNA-seq.
Specific Labeling of Stem Cell Activity in Human Colorectal Organoids Using an ASCL2-Responsive Minigene.
Subject
View SamplesGene expression profiles in Ba/F3 cells expressing ETV6-PDGFRB, FIP1L1-PDGFRA or a control vector, treated or not with imatinib (Glivec)
The expression of the tumour suppressor HBP1 is down-regulated by growth factors via the PI3K/PKB/FOXO pathway.
Specimen part, Cell line, Treatment
View SamplesRNA libraries from immunoprecipitates of Tdrd1, Ziwi and Zili, total testis RNA, total RNA from 3 week old wild-type and tdrd1 mutant gonads. Overall design: Both size selected and non-size selected libraries were made. Sequencing was performed using Illumina platform.
Tdrd1 acts as a molecular scaffold for Piwi proteins and piRNA targets in zebrafish.
No sample metadata fields
View SamplesHigh-fat diets are associated with increased obesity and metabolic disease in mice and humans. Here we used analysis of variance (ANOVA) to scrutinize a microarray data set consisting of 10 inbred strains of mice from both sexes fed atherogenic high-fat and control chow diets. An overall F-test was applied to the 40 unique groups of strain-diet-sex to identify 15,288 genes with altered transcription. Bootstrapping k-means clustering separated these changes into four strain-dependent expression patterns, including two sex-related profiles and two diet-related profiles. Sex-induced effects correspond to secretion (males) or fat and energy metabolism (females), whereas diet-induced changes relate to neurological processes (chow) or immune response (high-fat). The full set of pairwise contrasts for differences between strains within sex (90 different statistical tests) uncovered 32,379 total changes. These differences were unevenly distributed across strains and between sexes, indicating that strain-specific responses to high-fat diet differ between sexes. Correlations between expression levels and 8 obesity-related traits identified 5,274 associations between transcript abundance and measured phenotypic endpoints. From this number, 2,678 genes are positively correlated with total cholesterol levels and associate with immune-related categories while 2,596 genes are negatively correlated with cholesterol and connect to cholesterol synthesis.
Practical applications of the bioinformatics toolbox for narrowing quantitative trait loci.
Sex
View SamplesIdentify genes that are differentially regulated as a consequence of restoration of full-length functional APC in a colorectal cancer cell lines. Overall design: Examine mRNA expression level changes between SW480 (APC defective) and SW480+APC (SW480 cells with restored functional APC) cells, whilst accounting for any non-specific expression changes by comparison to SW480+control vector.
Differential RNA-seq analysis comparing APC-defective and APC-restored SW480 colorectal cancer cells.
No sample metadata fields
View SamplesHigh quality genetic material is an essential pre-requisite when analyzing gene expression using microarray technology. Peripheral blood mononuclear cells (PBMC) are frequently used for genomic analyses, but several factors can affect the integrity of nucleic acids prior to their extraction, including the methods of PBMC collection and isolation. In this study, we compared the Ficoll-Paque density gradient centrifugation and BD Vacutainer cell preparation tube (CPT) protocols to determine if either method offered a distinct advantage in preparation of PBMC-derived immune cell subsets for their use in gene expression analysis. We compared gene expression in PBMC and individual immune cell types from Ficoll and CPT isolation protocols using Affymetrix microarrays.
Immune cell subsets and their gene expression profiles from human PBMC isolated by Vacutainer Cell Preparation Tube (CPT™) and standard density gradient.
Specimen part
View SamplesCrosslinking and immunoprecipitation (CLIP) is increasingly used to map transcriptome-wide binding sites of RNA-binding proteins (RBPs). We developed a method for CLIP data analysis and applied it to compare 254 nm CLIP with PAR-CLIP, which involves crosslinking of photoreactive nucleotides with 365 nm UV light. We found small differences in the accuracy of these methods in identifying binding sites of HuR, a protein that binds low-complexity sequences and Argonaute 2, which has a complex binding specificity. We show that crosslink-induced mutations lead to single-nucleotide resolution for both PAR-CLIP and CLIP. Our results confirm the expectation from original CLIP publications that RNA-binding proteins do not protect sufficiently their sites under the denaturing conditions used during the CLIP procedure, and we show that extensive digestion with sequence-specific ribonucleases strongly biases the set of recovered binding sites. We finally show that this bias can be substantially reduced by milder nuclease digestion conditions. Overall design: We performed duplicate experiments for each variant of the CLIP protocol (CLIP, PAR-CLIP), each protein (HuR, Ago2), and enzymatic digestion (complete T1 digestion, mild MNase digestion). In addition, we performed a single PAR-CLIP experiment with mild T1 digestion.
A quantitative analysis of CLIP methods for identifying binding sites of RNA-binding proteins.
No sample metadata fields
View SamplesIn the marrow and lymphatic tissues, chronic lymphocytic leukemia (CLL) cells interact with accessory cells that constitute the leukemia microenvironment. In lymphatic tissues, CLL cells are interspersed with CD68+ nurselike cells (NLC) and T cells. However, the mechanism regulating co-localization of CLL cells and these accessory cells are largely unknown. To dissect the molecular cross-talk between CLL and NLC, we profiled the gene expression of CD19-purified CLL cells before and after co-culture with NLC. NLC co-culture induced high-level expression of B cell maturation antigen (BCMA) and two chemoattractants (CCL3, CCL4) by CLL cells. Supernatants from CLL-NLC co-cultures revealed high CCL3/CCL4 protein levels. B cell receptor triggering also induced a robust induction of CCL3 and CCL4 expression by CLL cells, which was almost completely abrogated by a specific Syc inhibitor, R406. High CCL3 and CCL4 plasma levels in CLL patients suggest that activation of this pathway plays a role in vivo. These studies reveal a novel mechanism of cross-talk between CLL cells and their microenvironment, namely the secretion of two T cell chemokines by CLL-NLC interaction and in response to BCR stimulation. Through these chemokines, CLL cells can recruit accessory cells, and thereby actively create a microenvironment that favors their growth and survival.
High-level expression of the T-cell chemokines CCL3 and CCL4 by chronic lymphocytic leukemia B cells in nurselike cell cocultures and after BCR stimulation.
No sample metadata fields
View SamplesThis study compares the gene expression changes in Sus scrofa in response to two different methods for abdominal surgical incisions ; electrosurgery and harmonic blade.
Ultrasonic incisions produce less inflammatory mediator response during early healing than electrosurgical incisions.
Specimen part, Treatment
View SamplesKey regulators of septum formation between the left and right ventricle in mammals, including the transcription factors TXB5 and PITX2, feature loss-of-function phenotypes that affect development of the two-chambered zebrafish heart, suggesting
Generating and evaluating a ranked candidate gene list for potential vertebrate heart field regulators.
Specimen part
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