Project description:Mex3a is an RNA binding protein of unknown function. To elucidate the contribution of Mex3a to tumoral heterogeneity, Mex3a KO organoids engineered by CRISPR were sequenced in three different conditions. Live organoids (DAPI negative) were sorted in Control, after 2 days of FOLFIRI and after 5 days of treatment. Two WT organoids (parental and a derived clone) and two KO (KO1 and KO2, two independent clones) were used for this experiment.
Project description:The aim of the experiment is to elucidate changes in tumor heterogeneity upon chemotherapy treatment. The experiment includes non-treated samples, samples right after chemotherapy treatment (FOLFIRI) and organoids recovered from FOLFIRI. It was conducted in two different genetic backgrounds, AKP (Apc KO, KrasG12D and P53 KO) and APS (Apc KO, P53 and Smad4KO). In addition to that, the organoids carry an inducible Cre-ERT2 knock-in allele in the mex3a locus. Upon 4-OH-Tamoxifen induction, Mex3a cells will recombine the tracing allele stop-TdTomato, enabling the tracing of this subpopulation. To understand the fate of the traced cells, samples right after chemotherapy and in the recovery setting were sorted based on their tomato expression. This enables a single cell tracing experiment.
Project description:Mex3a labells a subpopulation of Cancer Stem cells defined by their slow proliferative behaviour. Nevertheless, the precise function of MEX3A is unknown, although it plays a role in chemoresistance. The Mex3a KO adenomas are less chemoresistant compared to their WT controls. We used microarrays to elucidate changes in gene expression in cells with the Mex3a promoter active (tomato expressing cells)
Project description:To comprehensively capture changes in retinal transcriptome for the LCA7 organoids compared to control, we performed single cell RNA-sequencing (scRNAseq) using the 10X Genomics platform. Retinal organoids at D150 of differentiation were dissociated for scRNAseq analysis. scRNAseq data revealed significant dysregulation of specific photoreceptor genes between control and LCA7 organoids, as well as mutation-specific differences in various genes, including CRX, RCVRN, ARR3, and AIPL1.
Project description:Human induced pluripotent stem cell-derived kidney organoids have potential for disease modelling and regenerative medicine purposes. However, they lack a functional vasculature and remain immature in in vitro culture. Here, we transplanted kidney organoids at day 7+12 of differentiation in the coelomic cavity of chicken embryos and then compared them to their respective untransplanted controls at d7+13 and d7+20 using scRNAseq and imaging modalities. We demonstrate vascularization and enhanced maturation of transplanted kidney organoids.
Project description:Sadanandam et al. (2013) recently published a study based on the use of microarray data to classify colorectal cancer (CRC) samples. The classification claimed to have strong clinical implications, as reflected in the paper title: “A colorectal cancer classification system that associates cellular phenotype and responses to therapy”. They defined five subtypes: (i) inflammatory; (ii) goblet-like; (iii) enterocyte; (iv) transit-amplifying; and (v) stem-like. Based on drug sensitivity data from 21 patients, they also reported that the so-called stem-like subtype show differential sensitivity to FOLFIRI. This is the key result in their publication, since it implies a direct relation between the subtype and the choice of CRC therapy (i.e. FOLFIRI response). However, our analyses using the same drug sensitivity data and results from additional patients showed that the CRC classification reported by Sadanandam et al. is not predictive of FOLFIRI response.
Project description:Transcriptomic data related to 4 different subpopulations found in Mex3a Ki/+ Lgr5 Gfp in APCflfl adenomas in untreated animals. Adenomas where induced with 3%DSS and a single shot of 8mg/kg of Tamoxifen. The populations are refered as Mex3a + Lgr5, Mex3a- Lgr5+ Mex3a+ Lgr5- and Mex3a- Lgr5- according to the flow cytometry profile. Cells were isolated using FACsARIA (BD)
Project description:Human embryonic stem cell (hESC) line Man-13 was edited by CRISPR resulting in a hESC line carrying a heterozygous frameshift mutation with a premature stop codon in exon-1 of the HNF1B gene ([p.Val61Argfs*18]), functionally equivalent to a heterozygous whole-gene deletion. Kidney organoids were then created by differentiation (as per Takasato et al, 2015; Bantounas et al, 2018; Bantounas et al 2021) of this line and an isogenic non-mutant control line. Single-cell RNAseq (scRNAseq) was then performed on day-25 of differentiation to identify transcriptomic differences, as well as differences in identity and numbers of the cell populations comprising the organoids, with the aim of mechanistically explaining developmental aberrations observed in patients with mutations in this gene.
Project description:The effort to better understand intestinal stem cell (ISC) identity and regulation remains a challenge. We have been studying the RNA-binding protein MEX3A as a putative ISC marker. In that context, we have generated the first Mex3a knockout (KO) mouse model and show MEX3A is crucial for maintenance of the Lgr5+ ISC pool. As part of a phenotypic characterization pipeline, we have performed transcriptomic profiling (RNA-sequencing) of isolated Mex3a KO small intestinal crypts and compared it against small intestinal crypts isolated from age-matched wild-type controls.