Mitochondrial DNA (mtDNA) mutations cause inherited diseases and are implicated in the pathogenesis of common late-onset disorders, but it is not clear how they arise and propagate in the humans. Here we show that mtDNA mutations are present in primordial germ cells (PGCs) within healthy female human embryos. Close scrutiny revealed the signature of selection against non-synonymous variants in the protein-coding region, tRNA gene variants, and variants in specific regions of the non-coding D-loop. In isolated single PGCs we saw a profound reduction in the cellular mtDNA content, with discrete mitochondria containing ~5 mtDNA molecules during early germline development. Single cell deep mtDNA sequencing showed rare variants reaching higher heteroplasmy levels in later PGCs, consistent with the observed genetic bottleneck, and predicting >80% levels within isolated organelles. Genome-wide RNA-seq showed a progressive upregulation of genes involving mtDNA replication and transcription, linked to a transition from glycolytic to oxidative metabolism. The metabolic shift exposes deleterious mutations to selection at the organellar level during early germ cell development. In this way, the genetic bottleneck prevents the relentless accumulation of mtDNA mutations in the human population predicted by Muller's ratchet. Mutations escaping this mechanism will, however, show massive shifts in heteroplasmy levels within one human generation, explaining the extreme phenotypic variation seen in human pedigrees with inherited mtDNA disorders. Overall design: RNA-Seq and NGS analysis to investigate transcriptomes and mtDNA sequences of fetal hPGCs
Segregation of mitochondrial DNA heteroplasmy through a developmental genetic bottleneck in human embryos.
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View SamplesNext Generation Sequencing technologies have enabled de novo gene fusion discovery that could reveal candidates with therapeutic significance in cancer. Here we present an open-source software package, ChimeraScan, for the discovery of chimeric transcription between two independent transcripts. Overall design: Three cancer cell lines with known gene fusions
ChimeraScan: a tool for identifying chimeric transcription in sequencing data.
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View SamplesHigh quality RNA was extracted from the whole seedlings (Combined root and leaf samples) using TRI Reagent (Ambion, Inc. USA) and pooled from 12 independent stressed and non-stressed plant samples separately, and treated with DNase-I (QIAGEN GmbH, Germany). Subsequently, RNA cleanup was carried out using RNeasy Plant Mini Kit (QIAGEN GmbH, Germany) and 5 ug of total RNA from each sample in triplicates were reverse-transcribed to double stranded cDNA using the GeneChipᆴ One-Cycle cDNA Synthesis Kit. The biotin-labelled cRNA was made using the GeneChipᆴ IVT Labelling Kit (Affymetrix, CA, USA). Twenty microgram of cRNA samples was fragmented and out of which which 7.5 ug cRNA were hybridized for 16 hours at 45C to the Affymetrix GeneChipᆴ Rice Genome Array (Santa Clara, CA, USA). After washing and staining with R-phycoerythrin streptavidin in a Fluidics Station, using the Genechipᆴ Fluidics Station 450, the arrays were scanned by the Genechipᆴ 3000 Scanner. The chip images were scanned and extracted using default settings and the CEL files were produced with the Affymetrix GeneChip Operating Software (GCOS 1.2). The resulting .CEL files were imported into the GeneSpring GX 10 (Agilent Technologies Inc, Santa Clara CA) and normalized with the PLIER16 algorithm. The resulting expression values were log2-transformed. Average log signal intensity values of three technical replicates for each sample were used for advance analysis.
Comparative analysis of drought-responsive transcriptome in Indica rice genotypes with contrasting drought tolerance.
Specimen part
View SamplesProfiling of MCF-7 cell lines stably overexpressing constitutively active Raf-1, constitutively active MEK, constitutively active c-erbB-2, or ligand-activatable EGFR as models of overexpressed growth factor signaling, as well as control vector transfected cells (coMCF-7) and control vector transfected cells long-term adapted for estrogen-independent growth (coMCF-7/lt-E2).
Activation of mitogen-activated protein kinase in estrogen receptor alpha-positive breast cancer cells in vitro induces an in vivo molecular phenotype of estrogen receptor alpha-negative human breast tumors.
Cell line
View SamplesAndrogen receptor (AR) is a ligand-dependent transcription factor that plays a key role in the onset and progression of prostate cancer. Surprisingly little is known of AR binding sites and collaborating transcription factors in the human genome. Here we have identified the DNA sequence motifs that are significantly enriched within the authentic 90 AR target regions found on chromosomes 21 and 22 in human prostate cancer cells by combining chromatin immunoprecipitation for AR with chromosome-scale tiled oligonucleotide microarrays. By integrating the DNA sequence motif data with the gene expression profiles from human prostate cancers we identified the transcription factors that recognize each of these motifs. These factors form complexes with AR, bind to specific AR target regions and govern androgen-dependent transcription. Together with AR these collaborating transcription factors form a regulatory network that directs prostate cancer growth and survival and identify potential new opportunities for therapeutic intervention.
A hierarchical network of transcription factors governs androgen receptor-dependent prostate cancer growth.
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View SamplesAndrogens are required for the development of normal prostate, and they are also linked to the development of prostate cancer.
Proteomic interrogation of androgen action in prostate cancer cells reveals roles of aminoacyl tRNA synthetases.
Specimen part, Cell line
View SamplesWe compare the performance of two library preparation protocols (poly(A) and exome capture) in in vitro degraded RNA samples Overall design: VcaP cell were grown, and treated with MDV3100 (enzalutamide) or DHT (dihydrotestosterone), intact RNA was isolated and samples were prepared in technical triplicates using two library preparation protocol. Also cells were subject to in vitro degradation through incubation of the whole cell lysate in 37C for increasing amounts of time. Following incbation paired capture and poly(A) libraries were prepared.
The use of exome capture RNA-seq for highly degraded RNA with application to clinical cancer sequencing.
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View SamplesMyeloid-derived cells comprising the tumor stroma represent a heterogeneous population of cells critical to the structure, function and growth of established cancers. We have recently found that engineering tumor-specific CD8+ T cells to secrete IL-12 (IL-12TD) can lead to striking improvements in T-cell activity against established melanomas in murine models. Surprisingly, IL-12-dependent enhancement of CD8+ T-cell anti-tumor function did not occur through direct ligation of receptors on lymphocytes or NK cells. Instead, IL-12 sensitized host bone marrow-derived tumor-stromal cells, partly through interferon-gamma, to indirectly enhance the effects of adoptively-transferred T cells. Direct presentation of antigen by tumor was not necessary, but MHC class I expression on endogenous cells was essential for IL-12 mediated anti-tumor enhancements. Upon successful treatment with IL-12TD cells, we observed the selective elimination of tumor-infiltrating CD11b+ F4/80+ macrophages, CD11b+/ClassII+/CD11c+ dendritic cells and CD11b+/Ly6C+/Ly6G- but not CD11b+/Ly6C+/Ly6G+ myeloid-derived suppressor cells within regressing lesions. These results are consistent with a model whereby IL-12 triggers the maturation of myeloid-derived cells into competent antigen cross-presenting cells. Licensed recognition of these antigens by effector T cells may in turn trigger the collapse of the tumor stroma and aid in the regression of large vascularized lesions.
IL-12 triggers a programmatic change in dysfunctional myeloid-derived cells within mouse tumors.
Specimen part, Disease, Disease stage
View SamplesA growing body of evidence suggests that inflammatory cytokines have a dualistic role in immunity. In this study, we sought to determine the direct effects IFN-gamma on the differentiation and maturation of human peripheral blood monocyte-derived dendritic cells (moDC). Here, we report that following differentiation of human peripheral-blood monocytes into moDCs with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4, interferon-gamma (IFN-gamma) induces moDC maturation and up-regulates the co-stimulatory markers CD80, CD86, CD95, and MHC Class I, enabling moDCs to effectively generate antigen-specific CD4+ and CD8+ T cell responses for multiple viral and tumor antigens. Interestingly, early exposure of monocytes to high concentrations of IFN-gamma promotes monocyte differentiation into macrophages, despite the presence of GM-CSF and IL-4. However, under low concentrations of IFN-gamma, monocytes continue to differentiate into dendritic cells possessing a unique gene-expression profile, resulting in impairments in subsequent maturation by IFN-gamma and an inability to generate effective antigen-specific CD4+ and CD8+ T cell responses compared to standard moDCs. Monocytes differentiated in the presence of low levels of IFN-gamma downregulate IFN-gamma receptor expression, impairing their response to an inflammatory rechallenge. These findings demonstrate the ability of IFN-gamma to impart differential programs on human moDCs which shape the antigen-specific T cell responses they induce. Timing and intensity of exposure to IFN-gamma can thus determine whether moDCs are tolerogenic or immunostimulating.
Timing and intensity of exposure to interferon-γ critically determines the function of monocyte-derived dendritic cells.
Specimen part, Subject
View SamplesDendritic cells (DCs) are pivotal for both recognition of antigens and control of an array of immune responses by recognizing microbes through distinct pattern recognition receptors (PRRs). The first microbial component to be studied in detail and known to cause septic shock is endotoxin (LPS). DCs recognize LPS via Toll-like receptor TLR-47. LPS causes many changes in the DCs, but the elicitation of cytokine production is perhaps the one with clear biologic relevance.
Targeting of microRNA-142-3p in dendritic cells regulates endotoxin-induced mortality.
Specimen part, Treatment
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