ABSTRACT: Mice that are mutant for both Fgfr1 and Fgfr2 specifically in the developing retina develop coloboma. To analyze the transcripts that are affected by defective FGF signaling, we micro-dissected the optic fissure region from the control and FGFR condtional mutant mice and did microarray analysis. E11.5 control and Six3Cre+; Fgfr1fx/fx;Fgfr2 fx/fx optic fissures are dissected using laser-assisted micro-dissection microscope, RNAs are extracted and labelled and hybridyzed to chips
Project description:Mice that are mutant for both Fgfr1 and Fgfr2 specifically in the developing retina develop coloboma. To analyze the transcripts that are affected by defective FGF signaling, we micro-dissected the optic fissure region from the control and FGFR condtional mutant mice and did microarray analysis.
Project description:Incomplete fusion of the optic fissure leads to ocular coloboma, a congenital eye defect that affects up to 7.5 per 10,000 births and accounts for up to 10 percent of childhood blindness. The molecular and cellular mechanisms that facilitate optic fissure fusion remain elusive. We have profiled global gene expression during optic fissure morphogenesis by transcriptome analysis of tissue dissected from the margins of the zebrafish optic fissure and the opposing dorsal retina before (32 hours post fertilisation, hpf), during (48 hpf) and after (56 hpf) optic fissure fusion. Differential expression analysis between optic fissure and dorsal retinal tissue resulted in the detection of several known and novel developmental genes. The expression of selected genes was validated by qRT-PCR analysis and localisation investigated using in situ hybridisation. We discuss significantly overrepresented functional ontology categories in the context of optic fissure morphogenesis and highlight interesting transcripts from hierarchical clustering for subsequent analysis. We have identified netrin1a (ntn1a) as highly differentially expressed across optic fissure fusion, with a resultant ocular coloboma phenotype following morpholino antisense translation-blocking knockdown and downstream disruption of atoh7 expression. To support the identification of candidate genes in human studies, we have generated an online open-access resource for fast and simple quantitative querying of the gene expression data. Our study represents the first comprehensive analysis of the zebrafish optic fissure transcriptome and provides a valuable resource to facilitate our understanding of the complex aetiology of ocular coloboma.
Project description:The different stages of the optic fissure can be clearly visualized by making sagittal sections through the mouse eye during early development which represent the optic fissure at open (E10.5), closing (E11.5) and fused (E12.5) states. Laser capture microdissection (LCM) was employed to dissect tissue from the margins of the optic fissure consisting of the outer (presumptive RPE) and inner (presumptive neurosensory retina) layers of the retina. An approximately square-shaped block of optic fissure (50 x 50 mm) was dissected from each side of the fissure. Two rounds of linear amplification were performed on RNA isolated from each of the samples prior to microarray hybridization. Expression data were gathered in biological triplicate at E10.5, E11.5 and duplicate at E12.5, each array representing pooled optic fissure tissue from three embryos from a single litter. Expression signals were ascertained from 45,101 probe sets and normalized across arrays. Keywords: Time course
Project description:The different stages of the optic fissure can be clearly visualized by making sagittal sections through the mouse eye during early development which represent the optic fissure at open (E10.5), closing (E11.5) and fused (E12.5) states. Laser capture microdissection (LCM) was employed to dissect tissue from the margins of the optic fissure consisting of the outer (presumptive RPE) and inner (presumptive neurosensory retina) layers of the retina. An approximately square-shaped block of optic fissure (50 x 50 mm) was dissected from each side of the fissure. Two rounds of linear amplification were performed on RNA isolated from each of the samples prior to microarray hybridization. Expression data were gathered in biological triplicate at E10.5, E11.5 and duplicate at E12.5, each array representing pooled optic fissure tissue from three embryos from a single litter. Expression signals were ascertained from 45,101 probe sets and normalized across arrays. Experiment Overall Design: Differential gene expression over the course of three days in laser capture microdissected tissue from wild type mouse embryos.
Project description:We sought to identify gene expression signatures confined to the small group of cells at the fissure margins that are involved in OFC. Serial cryosections perpendicular to the optic fissure were prepared from mouse embryonic eyes (n=3 at E11.5 and n=3 at E12.5). The fissure margins and a corresponding control region of dorsal optic cup were isolated using laser capture microdissection. This study design aimed to identify the signature of gene expression in the OFC margins and to identify those genes that were more highly expressed along the ventral (inferior) fissure compared to the opposing dorsal (superior region). Fissure closure is active at E11.5 and complete by E12.5
Project description:We sought to identify gene expression signatures confined to the small group of cells at the fissure margins that are involved in OFC. Serial cryosections perpendicular to the optic fissure were prepared from human embryonic eyes (n=3, CS17-18, Day41-44(CS 17-18). The fissure margins and a corresponding control region of dorsal optic cup were isolated using laser capture microdissection. This study design aimed to identify the signature of gene expression in the OFC margins and to identify those genes that were more highly expressed along the ventral (inferior) fissure compared to the opposing dorsal (superior region). As CS17-18 (Day41-44) stages have active points of closure they were considered suitable for transcriptomic analyses of the process of human fissure closure.
Project description:A major risk factor for glaucomatous optic neuropathy is the level of intraocular pressure (IOP), which can lead to retinal ganglion cell axon injury and cell death. The optic nerve has a rostral unmyelinated portion at the optic nerve head followed by a caudal myelinated region. The unmyelinated region is differentially susceptible to IOP-induced damage in rodent models and in human glaucoma. While several studies have analyzed gene expression changes in the mouse optic nerve following optic nerve injury, few were designed to consider the regional gene expression differences that exist between these distinct areas. We performed bulk RNA-sequencing on the retina and on separately micro-dissected unmyelinated and myelinated optic nerve regions from naïve C57BL/6 mice, mice after optic nerve crush, and mice with microbead-induced experimental glaucoma (total = 36). Gene expression patterns in the naïve unmyelinated optic nerve showed significant enrichment of the Wnt, Hippo, PI3K-Akt, and transforming growth factor β pathways, as well as extracellular matrix–receptor and cell membrane signaling pathways, compared to the myelinated optic nerve and retina. Gene expression changes induced by both injuries were more extensive in the myelinated optic nerve than the unmyelinated region, and greater after nerve crush than glaucoma. Changes present three and fourteen days after injury largely subsided by six weeks. Gene markers of reactive astrocytes did not consistently differ between injury states. Overall, the transcriptomic phenotype of the mouse unmyelinated optic nerve was significantly different from immediately adjacent tissues, likely dominated by expression in astrocytes, whose junctional complexes are inherently important in responding to IOP elevation.
Project description:<p>In this study, patients with advanced cancer across all histologies were enrolled in our IRB approved clinical sequencing program, called MI-ONCOSEQ, to go through an integrative sequencing which includes whole exome sequencing of the tumor and matched normal, and transcriptome sequencing. Four index cases were identified which harbor gene rearrangements of FGFR2 including two cholangiocarcinoma cases, a metastatic breast cancer case, and a metastatic prostate cancer case. After extending our assessment of FGFR rearrangements across multiple tumor cohorts, including TCGA, we identified FGFR gene fusions with intact kinase domains of FGFR1, FGFR2, or FGFR3 in cholangiocarcinoma, breast cancer, prostate cancer, lung squamous cell cancer, bladder cancer, thyroid cancer, oral cancer, glioblastoma, and head and neck squamous cell cancer. All FGFR fusion partners tested exhibit oligomerization capability, suggesting a shared mode of kinase activation. Overexpression of FGFR fusion proteins in vitro induced cell proliferation, and bladder cancer cell lines that harbors FGFR3 fusion proteins exhibited enhanced susceptibility to pharmacologic inhibition in vitro and in vivo. Due to the combinatorial possibilities of FGFR family fusion to a variety of oligomerization partners, clinical sequencing efforts which incorporate transcriptome analysis for gene fusions are poised to identify rare, targetable FGFR fusions across diverse cancer types.</p>
Project description:Acquired resistance of gastrointestinal stromal tumors (GISTs) to imatinib mesylate (IM) is one of the most critical challenges in GIST therapy. Here we show that a long-term culture of GIST T-1 cells with IM induces clonal heterogeneity resulting in the appearance of cancer cells exhibiting activation of the FGFR-signaling pathway which was associated with KIT loss. The first one was due to the overexpression of FGFR1/2 and increased production of FGF-2 ligand. These events maintained GIST resistance to IM and rendered these GIST cells highly sensitive to all types of pan-FGFR-inhibitors used in the current study. Knockout of FGFR2 in this GIST subclone significantly attenuated pro-apoptotic and anti-proliferative activities of infigratinib (BGJ 398) both in vitro and in vivo, thereby suggesting the activation of FGFR-signaling pathway via FGFR2-mediated axis as the predominant molecular mechanism in these GIST cells. Collectively, the extended inhibition of KIT-signaling in GISTs induces clonal heterogeneity of cancer cells and might change the tumor’s sensitivity to FGFR-inhibitors due to selection of cancer cells with an FGFR-overactivated pathway.