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: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:Rationale: Slit2 is a possible modulator of vascular endothelial growth factor (VEGF) - induced angiogenesis, but its effects have not been tested in large animal models. Objective: We studied the effect of Slit2 on therapeutic angiogenesis induced by VEGF receptor 2 (VEGFR2) ligands Vammin and VEGF-DΔNΔC in vivo in rabbit skeletal muscles. The Slit2 target genes were also studied by RNA sequencing (RNA-Seq) in endothelial cells. Methods and Results: Adenoviral intramuscular gene transfers were performed into rabbit hindlimbs. Confocal and multiphoton microscopy were used for blood vessel imaging. Signaling experiments and gene expression analyses were performed to study mechanisms of Slit2 action. Slit2 decreased VEGFR2-mediated vascular permeability. It also reduced VEGFR2-mediated increase in blood perfusion and capillary enlargement, whereas sprouting of the capillaries was increased. Slit2 gene transfer alone did not have any effects on vascular functions or morphology. VEGFR2 activation was not affected by Slit2, but eNOS phosphorylation was diminished. The transcriptome profiling showed Slit2 downregulating angiogenesis-related genes such as nuclear receptor subfamily 4 group A member 1 (NR4A1) and Stanniocalcin-1 (STC-1) as well as genes related to endothelial cell migration and vascular permeability. Conclusions: Combining Slit2 with VEGFs adjusts VEGFR2-mediated angiogenic effects into a more physiological direction. This possibly allows the use of higher VEGF vector doses to achieve a more widespread vector and VEGF distribution in the target tissues leading to a better therapeutic outcome while reducing excess vascular permeability.
