Obstructive sleep apnea (OSA) leads to increased cardiovascular morbidity and mortality, which have been attributed to intermittent hypoxia (IH). The effects of IH on lung structure and function are unknown. We used a mouse model of chronic IH, which mimics the O2 profile in patients with OSA. We exposed adult C57BL/6J mice to 3 months of IH with an FIO2 nadir of 5%, 60 times/hr during the 12hr light phase. Control mice were exposed to room air.
Chronic intermittent hypoxia induces lung growth in adult mice.
Sex, Specimen part
View Samplesp53 is a frequent target for mutation in human tumors and previous studies have revealed that these missense mutant proteins can actively contribute to tumorigenesis. To elucidate how mutant p53 might contribute to mammary carcinogenesis we employed a three-dimensional (3D) culture model. In 3D culture non-malignant breast epithelial cells form structures reminiscent of acinar structures found in vivo, whereas breast cancer cells form highly disorganized and in some cases invasive structures. We found that mutant p53 depletion is sufficient to phenotypically revert breast cancer cells to a more acinar-like morphology. Genome-wide expression analysis identified the sterol biosynthesis, or mevalonate, pathway as significantly upregulated by a tumor-derived mutant p53. Using statins and sterol biosynthesis intermediates, we demonstrate that this pathway is both necessary and sufficient for the phenotypic effects of mutant p53 on breast tissue architecture. Mutant p53 associates with the sterol gene promoters at least partly via the SREBP transcription factors. Finally, p53 mutation correlates with higher levels of sterol biosynthesis genes in human breast tumors. This activity of mutant p53 not only contributes insight into breast carcinogenesis, but also implicates the mevalonate pathway as a new therapeutic target for tumors bearing such mutations in p53.
Mutant p53 disrupts mammary tissue architecture via the mevalonate pathway.
Specimen part, Cell line
View SamplesSeveral aspects common to a Western lifestyle, including obesity and decreased physical activity, are known risks for gastrointestinal cancers. There is an increasing amount of evidence suggesting that diet profoundly affects the composition of the intestinal microbiota. Moreover, there is now unequivocal evidence linking a dysbiotic gut to cancer development. Yet, the mechanisms through which high-fat diet (HFD)-mediated changes in the microbial community impact the severity of tumorigenesis in the gut, remain to be determined.
High-fat-diet-mediated dysbiosis promotes intestinal carcinogenesis independently of obesity.
Sex, Age, Specimen part, Treatment
View SamplesThese experiments are designed to discover genes that are expressed selectively by synaptic nuclei in skeletal muscle with the particular goal of identifying genes that regulate motor axon growth and differentiation.
CD24 is expressed by myofiber synaptic nuclei and regulates synaptic transmission.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative genomics identifies molecular alterations that challenge the linear model of melanoma progression.
Cell line
View SamplesThe two most common melanoma histopathologic subtypes, superficial spreading (SSM) and nodular melanoma (NM), are believed to represent sequential phases of linear progression from radial to vertical growth. Studies suggest, however, that SSM and NM are biologically distinct. We utilized an integrative genomic approach to examine the possibility that SSM and NM are the result of independent pathways characterized by unique molecular alterations. Cell lines including SSM, NM, metastatic melanoma, and melanocyte controls were evaluated for copy number changes and differential mRNA expression using single nucleotide polymorphism array (SNP 6.0, Affymetrix) and gene array (U133A 2.0, Affymetrix). Data sets were integrated to identify copy number alterations that correlated with gene expression, and array results were validated using immunohistochemistry on human tissue microarrays (TMAs) and an external data set. The functional effect of genomic deletion was assessed by lentiviral overexpression. Integrative genomics revealed 8 genes in which NM/SSM-specific copy number alterations were correlated with NM/SSM differential gene expression (P<0.05, Spearmans rank). Pathways analysis of differentially expressed genes (N=114) showed enrichment for metabolic-related processes. SSM-specific genomic deletions (DIS3, MTAP, G3BP2, SEC23IP, USO1) were verified in an expanded panel of cell lines, and forced overexpression of MTAP in SSM resulted in reduced cell growth. Metabolism-related gene ALDH7A1 was verified as overexpressed in NM using human TMAs.The identification of recurrent genomic deletions in SSM not present in NM challenges the linear model of melanoma progression and supports the unique molecular classification of SSM and NM.
Integrative genomics identifies molecular alterations that challenge the linear model of melanoma progression.
Cell line
View SamplesAlternative mRNA splicing is an important mechanism for regulation of gene expression. Changes in gene expression contribute to the pathogenesis of heart failure. However, changes in mRNA splicing have not been systematically examined in heart disease. We hypothesized that mRNA splicing is changed in diseased hearts.
Heart failure-associated changes in RNA splicing of sarcomere genes.
No sample metadata fields
View SamplesThe scaffold attachment factors SAFB1 and SAFB2 are paralogs, which are involved in cell cycle regulation, apoptosis, differentiation, and stress response. They have been shown to function as estrogen receptor co-repressors, and there is evidence for a role in breast tumorigenesis. To identify their endogenous target genes in MCF-7 breast cancer cells, we utilized gene expression array analysis, which was set up in a two-by-four design, with vehicle and estrogen treatment, and control, SAFB1, SAFB2, and SAFB1/SAFB2 siRNA as variables. Using custom chips containing 1.5 kb upstream regulatory region, we identified 541 SAFB1/SAFB2 binding sites in promoters of known genes, with significant enrichment on chromosome 1 and 6. Gene expression analysis revealed that the majority of target genes were induced in the absence of SAFB1 or SAFB2, and less were repressed. In contrast to SAFB2, which shared most of its target genes with SAFB1, SAFB1 had many unique target genes, most of them involved in regulation of the immune system. A subsequent analysis of the estrogen treatment group revealed that twelve percent of estrogen-regulated genes were dependent on SAFB1, with the majority being estrogen-repressed genes. These were primarily genes involved in apoptosis, such as BBC3, NEDD9, and OPG. Thus, this study confirms SAFB1/SAFB2s primary role as co-repressors, and also uncovers a previously unknown role for SAFB1 in regulation of immune genes, and in estrogen-mediated repression of genes.
SAFB1 mediates repression of immune regulators and apoptotic genes in breast cancer cells.
Cell line, Treatment
View SamplesThe undifferentiated spermatogonial population of mouse testis is known to be functionally heterogeneous and contain both stem cells and committed progenitor cells. However, gene expression patterns marking these distinct cell fractions are poorly defined. We found that a subset of undifferentiated spermatogonia were marked by expression of a PDX1-GFP transgene but properties of these cells were unclear. Undifferentiated cells were therefore isolated from adult testes and separated according to expression of PDX1-GFP+ for gene expression analysis by RNA-seq. Our goal was to identify differentially expressed genes from PDX1-GFP+ vs PDX1-GFP- with that of known markers of stem and committed progenitor cells. Overall design: 4 independent sets of PDX1-GFP-positive and PDX1-GFP-negative undifferentiated spermatogonia were isolated by flow sorting from adult mouse testes.
Identification of dynamic undifferentiated cell states within the male germline.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Zebrafish Pou5f1-dependent transcriptional networks in temporal control of early development.
No sample metadata fields
View Samples