Thirty-eight tumors from 17 patients treated with BRAF inhibitor (n=12) or combination BRAF/MEK inhibitors (n=5) with known PD-L1 expression were analyzed. RNA expression arrays were performed on all pre-treatment (PRE, n=17), early during treatment (EDT, n=8) and progression (PROG, n=13) biopsies. HLA-A/HLA-DPB1 expression was assessed by immunohistochemistry (IHC). Gene set enrichment analysis (GSEA) of PRE, EDT and PROG melanomas revealed that transcriptome signatures indicative of immune cell activation were strongly positively correlated with PD-L1 staining. In contrast, MAPK signaling and canonical Wnt/--catenin activity were negatively associated with PD-L1 melanoma expression. The expression of PD-L1 and immune activation signatures did not simply reflect the degree or type of immune cell infiltration, and was not sufficient for tumor response to MAPK inhibition.
PD-L1 Expression and Immune Escape in Melanoma Resistance to MAPK Inhibitors.
Specimen part
View SamplesCutaneous, acral and mucosal subtypes of melanoma were evaluated by whole-genome sequencing, revealing genes affected by novel recurrent mutations to the promoter (TERT, DPH3, OXNAD1, RPL13A, RALY, RPL18A, AP2A1), 5-UTR (HNRNPUL1, CCDC77, PES1), and 3-UTR (DYNAP, CHIT1, FUT9, CCDC141, CDH9, PTPRT) regions. TERT promoter mutations had the highest frequency of any mutation, but neither they nor ATRX mutations, associated with the alternative telomere lengthening mechanism, were correlated with greater telomere length. Genomic landscapes largely reflected ultraviolet radiation mutagenesis in cutaneous melanoma and provided novel insights into melanoma pathogenesis. In contrast, acral and mucosal melanomas exhibited predominantly structural changes, and mutation signatures of unknown aetiology not previously identified in melanoma. The majority of melanomas had potentially actionable mutations, most of which were in components of the mitogen-activated protein kinase and phosphoinositol kinase pathways.
Whole-genome landscapes of major melanoma subtypes.
No sample metadata fields
View SamplesThe sensation of light is initiated in photoreceptor cells by the photoisomerization of a chromophore molecule from 11-cis to all-trans retinal. Continuous visual perception requires recycling of the spent chromophore back to the 11-cis form through the visual cycle, a series of reactions in the retinal pigmented epithelium (RPE). Light-driven chromophore consumption by photoreceptors is greater in daytime compared to night time, suggesting that correspondingly higher activity of the visual cycle may be required. On the other hand, as rod photoreceptors are saturated in bright light, the continuous turnover of their chromophore through the visual cycle during daytime would unnecessarily utilize precious energy and produce toxic byproducts. Here, we sought to determine whether the recycling of chromophore and the dark adaptation of rods is regulated by the circadian clock and light exposure. We demonstrate that in melatonin-proficient C3H/f+/+ mice, rod dark adaptation is slower during the day or after light exposure. This surprising daytime downregulation of the RPE visual cycle was further demonstrated by gene analysis, which revealed light-driven reduction in the expression of Rpe65, which encodes a key enzyme of the RPE visual cycle. In contrast, rods in melatonin-deficient strains (C57BL6/J and 129/Sv) were not affected by this daily visual cycle modulation. Our results demonstrate that the circadian clock and light exposure regulate the recycling of chromophore in the RPE visual cycle. This daily modulation of rod dark adaptation is mediated by melatonin and could potentially protect the retina from light-induced damage during the day. Overall design: mRNA-seq of murine eyes (lens removed) in objective day (OD) vs. subjective day (SD) conditions (2 biological replicates per condition). Each biological replicate consisted of 4 eyes (from 1 female and 1 male).
Circadian and light-driven regulation of rod dark adaptation.
No sample metadata fields
View SamplesBackground: Mutations in the cone-rod-homeobox protein CRX are typically associated with dominant blinding retinopathies with variable age of onset and severity. Five well-characterized mouse models carrying different Crx mutations show a wide range of disease phenotypes. To determine if the phenotype variability correlates with distinct changes in CRX target gene expression, we perform RNA-seq analyses on three of these models and compare the results with published data. Results: Despite dramatic phenotypic differences between the three models tested, graded expression changes in shared sets of genes are detected. Phenotype severity correlates with the down-regulation of genes encoding key rod and cone phototransduction proteins. Interestingly, in increasingly severe mouse models, the transcription of many rod-enriched genes decreases decrementally, whereas that of cone-enriched genes increases incrementally. Unlike down-regulated genes, which show a high degree of CRX binding and dynamic epigenetic profiles in normal retinas, the up-regulated cone-enriched genes do not correlate with direct activity of CRX, but instead likely reflect a change in rod cell-fate integrity. Furthermore, these analyses describe the impact of minor gene expression changes on the phenotype, as two mutants showed marginally distinguishable expression patterns but huge phenotypic differences, including distinct mechanisms of retinal degeneration. Conclusions: Our results implicate a threshold effect of gene expression level on photoreceptor function and survival, highlight the importance of CRX in photoreceptor subtype development and maintenance, and provide a molecular basis for phenotype variability in CRX-associated retinopathies. Overall design: All genotypes were analyzed in triplicate. Heterozygous and homozygous mutants were all sequenced at P10, the control for which is the P10 C57BL6/J data. Heterozygous mutants were also analyzed at P21, the control for which is the P21 C57BL6/J data.
Graded gene expression changes determine phenotype severity in mouse models of CRX-associated retinopathies.
No sample metadata fields
View SamplesGenes related to AMPK activation, cellular respiration, and metabolism are enriched in the gastric parietal cell population. Metformin is known activator of AMPK.
A Metformin-Responsive Metabolic Pathway Controls Distinct Steps in Gastric Progenitor Fate Decisions and Maturation.
Specimen part
View SamplesWe report RNAseq analysis of the transcriptome of retinas from mature rod-specific Dicer1 cKO mice and control littermates lacking Cre expression in order to better understand changes in gene regulation that could lead to retinal degeneration in cKO mice. Overall design: Examine retinal transcriptome of 3 biological replicates for each genotype from 4-week-old animals with tissue collected between 8:00 - 10:00AM
DICER1 is essential for survival of postmitotic rod photoreceptor cells in mice.
No sample metadata fields
View SamplesWe report RNAseq analysis of the transcriptome of retinas from mature rod-specific Dicer1 cKO mice and control littermates lacking Cre expression in order to better understand changes in gene regulation that could lead to retinal degeneration in cKO mice. Overall design: Examine retinal transcriptome of 3 biological replicates for each genotype from 4-week-old animals with tissue collected between 8:00 - 10:00AM
DICER1 is essential for survival of postmitotic rod photoreceptor cells in mice.
No sample metadata fields
View SamplesPigment regeneration is critical for the function of cone photoreceptors in bright and rapidly-changing light conditions. This process is facilitated by the recently-characterized retina visual cycle, in which Müller cells recycle spent all-trans-retinol visual chromophore back to 11-cis-retinol. This 11-cis-retinol is oxidized selectively in cones to the 11-cis-retinal used for pigment regeneration. However, the enzyme responsible for the oxidation of 11-cis-retinol remains unknown. Here, we sought to determine whether retinol dehydrogenase 10 (RDH10), upregulated in rod/cone hybrid retinas and expressed abundantly in Müller cells, is the enzyme that drives this reaction. We created mice lacking RDH10 either in cone photoreceptors, Müller cells, or the entire retina. In vivo electroretinography and transretinal recordings revealed normal cone photoresponses in all RDH10-deficient mouse lines. Notably, their cone-driven dark adaptation both in vivo and in isolated retina was unaffected, indicating that RDH10 is not required for the function of the retina visual cycle. We also generated transgenic mice expressing RDH10 ectopically in rod cells. However, rod dark adaptation was unaffected by the expression of RDH10 and transgenic rods were unable to use cis-retinol for pigment regeneration. We conclude that RDH10 is not the dominant retina 11-cis-RDH, leaving its primary function in the retina unknown. Overall design: Retinas from rd7 and wild-type (C57BL/6J) mice at age 21 days were harvested. Two biological replicates per strain were collected. Each replicate consisted of 8 retinas total from two female and two male mice. RNA was extracted with Trizol, polyA-selected, and processed for mRNA-seq. All four samples were sequenced on a single lane of Illumina HiSeq 2000 (1x50 bp). Note that Nr2e3 transcript levels are higher in the rd7 mutant, as previously reported (Chen et al 2006 Hum Mol Genet 15(13):2146-56).
The role of retinol dehydrogenase 10 in the cone visual cycle.
Age, Cell line, Subject
View SamplesWe report RNA-Seq analysis of the transcriptome of retinas and RPE/choroids from Abca4 knockout, Abca4 L541P;A1038V knockin and control wild type mice in order to better understand changes in gene regulation that could lead to retinal pathology in mice with ABCA4 deficiency/defect. Overall design: Retinal and RPE/choroidal mRNA profiles of 30-day-old wild type (WT), Abca4-/- and Abca4L541P;A1038V/L541P;A1038V mice were generated by RNA-Seq, using Illumina Hiseq 2500
Protein misfolding and the pathogenesis of ABCA4-associated retinal degenerations.
No sample metadata fields
View Samples