RNA from MCF-7 cells was fractionated by sucrose density gradient centrifugation to separate RNA associated with membrane-bound polysomes from RNA associated with free polysomes. These two populations were hybridized in triplicate to U133A microarrays.
Membrane-associated and secreted genes in breast cancer.
No sample metadata fieldsView Samples
Nr4a1 deficient rats (Nr4a1-/-) were developed using the fawn hooded hypertensive rat (FHH), which provided a genetic background susceptible to kidney injury. Both groups of animals were evaluated for blood pressure, proteinuria, renal function, and whole transcriptome gene pathway changes. Gene expression profiling was performed at week 8, 16, and 24 using kidney from FHH and Nr4a1-/- rats. To identify differentially expressed gene between FHH and Nr4a1-/- two statistical methods were utilized: (1) FWER (family-wise error rate) procedure, p<0.05 and fold-change 1.2 or greater; and/or (2) Benjamani and Hochberg FDR (false discovery rate) using p<0.05, and fold-change 1.2 or greater. Two-way ANOVA using a p<0.01 or lower was performed to identify strain X time interaction effects between groups. Gene networks and functional analysis were evaluated through the use of Ingenuity Pathways Analysis .
Genetic susceptibility and loss of Nr4a1 enhances macrophage-mediated renal injury in CKD.
Age, Specimen partView Samples
Molecular programs that mediate normal cell differentiation are required for oncogenesis and tumor cell survival in certain cancers. How cell-lineage-restricted genes specifically influence metastasis is poorly defined. In lung cancers, we uncovered a transcriptional program that is preferentially associated with distal airway epithelial differentiation and lung adenocarcinoma (ADC) progression. This program is regulated in part by the lineage transcription factors GATA6 and HOPX. These factors can cooperatively limit the metastatic competence of ADC cells, by modulating overlapping alveolar differentiation and invasogenic target genes. Thus, GATA6 and HOPX are critical nodes in a lineage-selective pathway that directly links effectors of airway epithelial specification to the inhibition of metastasis in the lung ADC subtype. Overall design: mRNA profiles of human lung Adenocarcinoma PC9 cell lines infected with lentivirus harboring shRNA of control and shRNA of both GATA6 and HOPX were generated by deep sequencing, in triplicate, using Illumina HiSeq2000.
Control of alveolar differentiation by the lineage transcription factors GATA6 and HOPX inhibits lung adenocarcinoma metastasis.
Specimen part, Cell line, SubjectView Samples
Mutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains. Overall design: Purpose: Mutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains. Methods: Wild type (C57BL6/J â€“ C57n:C57mt and C3H/HeN - C3Hn:C3Hmt) and MNX (C57n:C3Hmt and C3Hn:C57mt) mouse were weaned with Chor diet and continued with Chow or changed to high-fat diet from 6 to 12-13 weeks of age. RNA samples were isolated from white adipose tissues collected from epididymal (eWAT) and inguinal (iWAT) fat, representing visceral and subcutaneous fat depots, respectively with RNeasy kit (Qiagen). Reverse transcribed cDNA libraries were sequenced with an Illumina HiSeq 2000. Read mapping was conducted with a proprietary algorithm by Expression Analysis (www.q2labsolutions.com), and read counts were used as input for differential expression analysis in DESeq2 version 1.10.1, using default settings. Results: Using an optimized data analysis workflow, we mapped about 20 million sequence reads per sample to the mouse genome (build mm9). Transcriptional changes were interrogated for 961 genes previously reported to be associated with fat metabolism and 29,209 genes representing the entire mouse transcriptome. These results show that the C57 mtDNA increased the number of DE genes in response to high fat diet in mice harboring the C3H nuclear genome (209% increase; C3Hn:C57mt versus C3Hn:C3Hmt, 165/79) and the C3H mtDNA decreased response in animals carrying the C57 nucleus (46% decrease; C57n:C3Hmt versus C57n:C57mt, 112/206) in eWAT (Figure 2B). Similarly, the high fat diet resulted in 25 and 231 DE genes in the C3Hn:C3Hmt and C3Hn:C57mt iWAT, respectively, and 344 and 143 DE genes in C57n:C57mt and C57n:C3Hmt iWAT. This corresponded to a 924% increase in the number of DE genes responding to high fat diet C3Hn:C57mt versus C3Hn:C3Hmt, and a decreased response (58% decrease) in C57n:C3Hmt relative to C57n:C57mt iWAT. Further analysis showed that each MNX and corresponding wild-type shared and had distinct DE genes in eWAT and iWAT. Conclusions: Results also show that the degree of transcriptional response influenced by the mtDNA can vary based upon the type of adipose tissue, suggesting that mtDNA background can have varying effects on the number of nuclear genes differentially responding to stimuli, depending upon tissue and location.
Mitochondrial - nuclear genetic interaction modulates whole body metabolism, adiposity and gene expression in vivo.
Specimen part, SubjectView Samples
The hypothalamus has recently emerged as a key regulator of metabolism and aging in mammals. We have examined the impact of targeted disruption of hypothalamic hypophysiotropic peptide: Growth Hormone-releasing Hormone (GHRH) in mice on longevity, and the putative mechanisms of delayed aging. GHRH knockout (KO) mice are remarkably long-lived and in comparison to genetically normal (wild type) animals exhibiting major shifts in the expression of genes related to xenobiotic detoxification, stress resistance, and insulin signaling. These mutant mice also have increased adiponectin levels and alterations in glucose homeostasis consistent with the removal of the counter-insulin effects of GH. While these effects overlap with those of caloric restriction (CR), we show that effects of CR and the GHRH mutation are additive, with lifespan of GHRH-KO mutants further increased by CR. We conclude that GHRH-KO mice feature perturbations in a network of signaling pathways related to stress resistance, metabolic control and inflammation, and therefore provide a new model that can be used to explore links between GHRH repression, downregulation of the somatotropic axis, and extended longevity.
Growth hormone-releasing hormone disruption extends lifespan and regulates response to caloric restriction in mice.
Sex, Specimen partView Samples
Genomics has provided a detailed structural description of the cancer genome. Identifying oncogenic drivers that work primarily through dosage changes is a current challenge. Unrestrained proliferation is a critical hallmark of human cancer. We constructed modular, barcoded libraries of human open reading frames (ORFs) and performed screens for proliferation regulators in multiple cell types. Approximately 10% of genes tested regulate proliferation, many performing in an unexpectedly highly tissue-specific manner. Proliferation drivers in a given cell type showed specific enrichment in SCNAs (somatic copy number changes) from cognate tumors and helped predict aneuploidy patterns in those tumors, implying that tissue type-specific genetic network architectures underlie SCNA selection in different cancers. In vivo screening confirmed these results. We report a substantial contribution to the catalog of SCNA-associated cancer drivers, identifying 147 amplified and 107 deleted genes as potential drivers, and derive new insights about the genetic network architecture of aneuploidy in tumors. KRTAPs are a class of human genes that promote proliferation in mammary epithelial cells (HMEC), but the mechanism is not understood. We performed RNAseq to study transcriptional changes associated with oeverxepression of KRTAPs and other oncogenes in hTERT-immortalized human mammary epithelial cells. GSEA analysis revealed the top enriched pathways upregulated by KRTAP expression are E2F-mediated regulation of DNA replication, G1-S specific transcription, cell cycle, translation and ribosome. KRTAP-induced mRNA changes are most closely related to those due to CCND1 expression, including induction of E2F1 transcription factor. Overall design: Analysis of whole transcriptome in HMEC overexpressing different human genes.
Profound Tissue Specificity in Proliferation Control Underlies Cancer Drivers and Aneuploidy Patterns.
Specimen part, Disease, SubjectView Samples
Monoclonal antibodies (mAbs) targeting the oncogenic receptor tyrosine kinase ERBB2/HER2, such as Trastuzumab, are the standard of care therapy for breast cancers driven by ERBB2 overexpression and activation. However, a substantial proportion of patients exhibits de novo resistance. Here, by comparing matched Trastuzumab-naïve and post-treatment patient samples from a neoadjuvant trial, we link resistance with elevation of H3K27me3, a repressive histone modification catalyzed by Polycomb Repressor Complex 2 (PRC2). In ErbB2+ breast cancer models, PRC2 silences endogenous retroviruses (ERVs) to suppress anti-tumor Type-I interferon (IFN) responses. In patients, elevated H3K27me3 in tumor cells following Trastuzumab treatment correlates with suppression of IFN-driven viral defense gene expression signatures and poor response. Using an immunocompetent model, we provide evidence that EZH2 inhibitors promote IFN-driven immune responses that enhance the efficacy of anti-ErbB2 mAbs, suggesting the potential clinical benefit of epigenomic reprogramming by H3K27me3 depletion in Trastuzumab-resistant disease.
Reduction of Global H3K27me<sup>3</sup> Enhances HER2/ErbB2 Targeted Therapy.
Sex, Specimen part, TreatmentView Samples
Down syndrome (DS, trisomy 21) is associated with developmental abnormalities and increased leukemia risk. To reconcile chromatin alterations with transcriptome changes in cells with trisomy 21, we performed paired exogenous spike-in normalized RNA and chromatin immunoprecipitation sequencing in DS models. Absolute per cell normalization unmasked global amplification of gene expression associated with trisomy 21. Overexpression of the nucleosome binding protein HMGN1 (encoded on chr21q22) recapitulated the transcriptional changes seen with triplication of a “Down syndrome critical region” on distal chromosome 21. Absolute exogenous normalized ChIP-seq (ChIP-Rx) also revealed a global increase in histone 3 lysine 27 acetylation caused by HMGN1. Genes most amplified downstream of HMGN1 were enriched for tumor- and developmental stage-specific programs of B-cell acute lymphoblastic leukemia dependent on the cellular context. These data offer a mechanistic explanation for DS transcriptional patterns, and suggest that further study of HMGN1 and RNA amplification in diverse DS phenotypes is warranted. Overall design: SLAM-seq in NALM6 human pre-B cells with engineered HMGN1 overexpression
Trisomy of a Down Syndrome Critical Region Globally Amplifies Transcription via HMGN1 Overexpression.
Cell line, Treatment, SubjectView Samples
Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients whose tumors exhibit overexpression or amplification of the MYC oncogene (c-MYC) usually have an extremely poor prognosis, but there are no animal models of this subtype of the disease. Here we show that cerebellar stem cells expressing Myc and mutant Trp53 (p53) generate aggressive tumors following orthotopic transplantation. These tumors consist of large, pleiomorphic cells and resemble human MYC-driven MB at a molecular level. Notably, antagonists of PI3K/mTOR signaling, but not Hedgehog signaling, inhibit growth of tumor cells. These findings suggest that cerebellar stem cells can give rise to MYC-driven MB, and identify a novel model that can be used to test therapies for this devastating disease.
An animal model of MYC-driven medulloblastoma.
Specimen partView Samples
Myc is an oncogenic transcription factor frequently dysregulated in human cancer. To identify pathways supporting the Myc oncogenic program, we employed a genome-wide RNAi screen for Myc-synthetic-lethal (MySL) genes and uncovered a role for the SUMO-activating-enzyme (SAE1/2). Loss of SAE1/2 enzymatic activity drives synthetic lethality with Myc. Mechanistically, SAE2 inhibition switches a transcriptional subprogram of Myc from activated to repressed. A subset of these SUMOylation-dependent Myc-switchers (SMS genes) governs mitotic spindle function and is required to support the Myc oncogenic program.
A SUMOylation-dependent transcriptional subprogram is required for Myc-driven tumorigenesis.
Cell line, TreatmentView Samples