Project description:The goal of the study was to compare gene expression of Robo1+/+ and Robo1-/- luminal progenitors. Total RNAs were then extracted from FACS purified luminal progenitor cells, harvested from Robo1+/+ or Robo1-/- mice (n=3 per genotype, two animals per n) using TRIreagent LS (Sigma, T3934). Poly(A)+ RNA sequencing libraries were made from each sample using the TruSeq RNA library preparation kit v.1 (Illumina). Illumina RNA PolyA library preparation guide. A total of 6 libraries were created by PCR amplification with Illumina barcoding primers using kit recommended conditions and quantified using a Bioanalyzer DNA 1000 kit (Agilent).
Project description:Id1 and its closely related family member Id3 are expressed by a diversity of stem and progenitor cells. We show that Id1/3 are required for the self-renewal and proliferation of triple negative breast cancer (TNBC) cells both in vitro and in vivo. Furthermore, we identified that Id1/3 negatively regulates the tumour suppressor gene Robo1. Depletion of Robo1 could rescue the proliferative defect induced by Id1/3 knockdown. To understand the mechanisms by which Robo1 rescues cell proliferation in Id1/3 depleted cells, we performed RNA-Sequencing on 4T1 cells with Dox-inducible Id1/3 KD and/or Robo1 depletion using siRNA. We conclude that following Id1/3 knockdown, Robo1 is induced and exerts anti-proliferative effects via suppression of a Myc transcriptional program.
Project description:We report here the transcriptional signature of Notch1-expressing (GFP positive) luminal mammary progenitors compared to total luminal cells (GFP negative). For each condition, 3 biological replicates were performed, by pooling the mammary glands from two mice/replicate.
Project description:We previously identified inactivating mutations in roundabout guidance receptor 1 (ROBO1) in patients with myelodysplastic syndrome (MDS), which was associated with poor prognosis and susceptibility to acute myeloid leukemia (AML) transformation. Nonetheless, the exact role of ROBO1 in hematopoiesis remains poorly delineated. Here we report that the ablation of Robo1 in mice is sufficient to confer MDS-like disease with anemia and multilineage dysplasia. More specifically, Robo1 deficiency impairs the self-renewal and differentiation capacity of hematopoietic stem progenitor cells (HSPCs) and disrupts HSPC pool, especially the reduction of megakaryocyte erythroid progenitors (MEPs), which causes a blockage in the early stages of erythropoiesis in mice. Similarly, Robo1-deficienct HSPCs recapitulated MDS-like disease with anemia and multilineage dysplasia in transplanted mice. Correspondingly, clinical data also reveal that low expression of ROBO1 is associated with shortened survival, severe anemia and a high risk of AML transformation in patients with MDS. Mechanistically, transcriptional profiling indicates that Cdc42, a member of the Rho-GTPase family, serves as a downstream target gene for Robo1 in HSPCs. Overexpression of Cdc42 partially restores the proliferation of erythroid colonies in Robo1 deficient mice. In contrast, Cdc42 inhibitor (CASIN) effectively attenuates the erythroid colony formation of HSPCs. Collectively, our results suggest that Robo1 deficiency may provide a promising therapeutic target against MDS by impairing HSPC self-renewal and erythropoiesis via CDC42, predicting a poor prognosis for severe anemia and a high risk of AML transformation in MDS.
Project description:Normal breast luminal epithelial progenitors have been implicated as cell of origin in basal-like breast cancer, but their anatomical localization remains understudied. Here, we combine micro-collection of uncultured organoids and single cell mRNA sequencing (scRNA-seq) of FACS-sorted luminal epithelial cells with multicolor imaging to profile ducts and terminal ductal lobular units (TDLUs) and compare them with breast cancer subtypes. Unsupervised clustering reveals eleven distinct clusters and a differentiation trajectory starting with keratin 15+ (K15+) progenitors enriched in ducts. Spatial mapping of luminal progenitors is confirmed at the protein level by staining with critical duct markers. Comparison of the gene expression profiles of normal luminal cells with those of breast cancer subtypes reveals a strong correlation between normal breast K15+ ductal progenitors and basal-like breast cancer. We propose that K15+ basal-like breast cancers originate in ductal progenitors, which emphasizes the importance of not only lineages but also cellular position within the ductal-lobular tree.
Project description:One of the major hurdles for the early detection of cancer is our poor understanding of tumour initiating events. Historically, cancer research has focused on histological and molecular characterisation of established tumours which has led to the identification of hundreds of putative driver mutations. It is currently unclear how these genetic aberrations impact the cell state of nascent tumour cells and their microenvironment. BRCA1 driven triple negative breast cancer (TNBC) for example has been shown to arise from luminal progenitor cells yet little is known about how BRCA1 loss-of-function (LOF) and concomitant mutations affect the luminal progenitor cell state. This repository contains ATAC-sequencing dataset of luminal progenitors isolated from 6-months old Brca1/p53 and wild-type mice. This data was used to show that the perturbation of Brca1/p53in luminal progenitors induces an aberrant alveolar differentiation pre-malignancy. Unlike alveolar differentiation occurring during gestation, this process is cell autonomous and characterised by the dysregulation of transcription factors driving alveologenesis. The ATAC-sequencing data supports a model where transcriptional and epigenetic changes driven by Brca1/p53 inadvertently promote a differentiation program hardwired in luminal progenitors, highlighting the deterministic role of the cell of origin and offering a potential explanation for the tissue specificity of BRCA1 tumours.
Project description:By using luminal lineage tracing model, here we report the regulatory network underlying intrinsically castration-resistant LY6D+ luminal progenitors during prostate tumourigenesis. The luminal cell-specific PTEN deficient mouse model of PCa (K8-CreERT2;PtenFlox/Flox;R26-StopFlox/Flox-EYFP (K8PY) and the control K8-CreERT2;R26-StopFlox/Flox-EYFP (K8Y) mice) are used in this study.
Project description:We report single cell RNA-seq data that reveals that Embryonic Multipotent Progenitors (EMPs) in the mammary gland express a unique hybrid basal and luminal signature associated with the different adult lineages.