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GSE36847
Homo sapiens
32 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Reduced cancer incidence has been reported among type II diabetics treated with metformin. Metformin exhibits anti-proliferative and anti-neoplastic effects associated with inhibition of mTORC1, but the mechanisms are poorly understood. We provide the first genome-wide analysis of translational targets of canonical mTOR inhibitors (rapamycin and PP242) and metformin, revealing that metformin controls gene expression at the level of mRNA translation to an extent comparable to that of canonical mTOR inhibitors. Importantly, metformin's anti-proliferative activity can be explained by selective translational suppression of mRNAs encoding cell cycle regulators via the mTORC1/4E-BP pathway. Thus, metformin selectively inhibits mRNA translation of encoded proteins that promote neoplastic proliferation, motivating further studies of this compound and related biguanides in cancer prevention and treatment.
Publication Title
Distinct perturbation of the translatome by the antidiabetic drug metformin.
Sample Metadata Fields
Cell line, Treatment
View Samples- Mus musculus
- 34 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
Pluripotent stem cells are derived from culture of early embryos or the germline, and can be induced by reprogramming of somatic cells. Barriers to reprogramming are expected to exist that stabilize the differentiated state and have tumor suppression functions. However, we have a limited understanding of what such barriers might be. To find novel barriers to reprogramming to pluripotency, we compared the transcriptional profiles of the mouse germline to pluripotent and somatic cells, in vivo and in vitro. There is a remarkable global expression of the transcriptional program for pluripotency in Primordial Germ Cells (PGCs). We identify parallels between PGCs reprogramming to pluripotency and human germ cell tumorigenesis, including the loss of LATS2, a tumor suppressor kinase of the Hippo pathway. We show that knockdown of LATS2 increases the efficiency of induction of pluripotency in human cells. LATS2 RNAi, unlike p53 RNAi, specifically enhances the generation of fully reprogrammed iPS cells without accelerating cell proliferation. We further show that LATS2 represses reprogramming in human cells by post-transcriptionally antagonizing TAZ but not YAP, two downstream effectors of the Hippo pathway. These results reveal transcriptional parallels between germ cell transformation and the generation of iPS cells, and indicate that the Hippo pathway constitutes a barrier to cellular reprogramming.
Publication Title
Transcriptional analysis of pluripotency reveals the Hippo pathway as a barrier to reprogramming.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 24 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Human induced pluripotent stem (iPS) cells are remarkably similar to embryonic stem (ES) cells, but recent reports indicate that there may be important differences between them. We carried out a systematic comparison of human iPS cells generated from hepatocytes (representative of endoderm), skin fibroblasts (mesoderm) and melanocytes (ectoderm). All low-passage iPS cells analysed retain a transcriptional memory of the original cells. The persistent expression of somatic genes can be partially explained by incomplete promoter DNA methylation. This epigenetic mechanism underlies a robust form of memory that can be found in iPS cells generated by multiple laboratories using different methods, including RNA transfection. Incompletely silenced genes tend to be isolated from other genes that are repressed during reprogramming, indicating that recruitment of the silencing machinery may be inefficient at isolated genes. Knockdown of the incompletely reprogrammed gene C9orf64 (chromosome 9 open reading frame 64) reduces the efficiency of human iPS cell generation, indicating that somatic memory genes may be functionally relevant during reprogramming.
Publication Title
Incomplete DNA methylation underlies a transcriptional memory of somatic cells in human iPS cells.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 30 Downloadable Samples
- Illumina MouseRef-8 v2.0 expression beadchip
Description
Metformin, a commonly used drug prescribed to treat type-2 diabetes, has been found to extend health span and delay cancer incidence and progression. Here, we report that starting chronic treatment with low dose of metformin (0.1% w/w in diet) at one year of age extends health and lifespan in male mice, while a higher dose (1% w/w) was toxic. Treatment with low dose metformin mimicked some of the benefits of calorie restriction, such as improved physical performance, increased insulin sensitivity, and reduced LDL and cholesterol levels. At a molecular level, metformin increased AMP-activated protein kinase activity without attenuation of the mitochondrial electron transport chain activities. Metformin treatment resulted in lower chronic inflammation and increased antioxidant protection, suggesting that the ability of metformin to improve health of laboratory animals may stem from these factors. Our results support that metformin supplementation could be beneficial in extending health and lifespan in humans.
Publication Title
Metformin improves healthspan and lifespan in mice.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The mRNA processing body is a cellular structure that regulates the stability of cytoplasmic mRNA. MARF1/LMKB is an RNA-binding protein that is associated with maintenance of mRNA homeostasis and genomic stability. To investigate the function of LMKB in a human B lymphocyte cell line, BJAB cells were treated with either control lentivirus or a lentivirus containing LMKB siRNA.
Publication Title
LMKB/MARF1 localizes to mRNA processing bodies, interacts with Ge-1, and regulates IFI44L gene expression.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 10 Downloadable Samples
NextSeq500
Description
Basal-like and luminal breast tumors have distinct clinical behavior and molecular profiles, yet the underlying mechanisms are poorly defined. To interrogate processes that determine these distinct phenotypes and their inheritance pattern, we generated somatic cell fusions and performed integrated genetic and epigenetic (DNA methylation and chromatin) profiling. We found that the basal-like trait is generally dominant and it is largely defined by epigenetic repression of luminal transcription factors. Definition of super-enhancers highlighted a core program common in luminal cells but high degree of heterogeneity in basal-like breast cancers that correlates with clinical outcome. We also found that protein extracts of basal-like cells is sufficient to induce luminal-to-basal phenotypic switch implying a trigger of basal-like autoregulatory circuits. We determined that KDM6A might be required for luminal-basal fusions, and identified EN1, TBX18, and TCF4 as candidate transcriptional regulators of luminal-to-basal switch. Our findings highlight the remarkable epigenetic plasticity of breast cancer cells. Overall design: RNA-Seq in breast cancer cell-lines
Publication Title
Somatic Cell Fusions Reveal Extensive Heterogeneity in Basal-like Breast Cancer.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Transcriptome Array 2.0 (hta20)
Description
Prostate cancer is the most commonly diagnosed malignancy in the United States. While the majority of cases are cured with radiation or surgery, about 1/3 of patients will develop metastatic disease which there is no cure, and has a life expectancy of less than 5 years. Identification of antigens associated with this transition to metastatic disease is crucial for future therapies. One such antigen of interest is the SSX gene family, which are cancer/testis antigens that are associated with the epithelial to mesenchymal transition in other cancer types. Prior work has shown that, in prostate cancer, SSX expression was restricted to metastatic tissue and not primary tumor tissue which may indicate a role in disease progression. Some work has been done into the function of the SSX family, which revealed transcriptional regulator activity. But neither the targets of this activity or the function of SSX are known. Through a transcriptomics approach, we are seeking a better understanding of the different genes and pathways SSX regulates in the context of prostate cancer, and to determine if these pathways may contribute to disease progression.
Publication Title
SSX2 regulates focal adhesion but does not drive the epithelial to mesenchymal transition in prostate cancer.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 32 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Primary human hepatocytes (PHH) are a main instrument in drug metabolism research and in the prediction of drug-induced phase I/II enzyme induction in humans. The HepG2 liver-derived cell line is commonly used as a surrogate for human hepatocytes, but their use in ADME and toxicity studies can be limited because of lowered basal levels of metabolizing enzymes. Despite their widespread use, the transcriptome of HepG2 cells compared to PHH is not well characterized. In this study, microarray analysis was conducted to ascertain the differences and similarities in mRNA expression between HepG2 cells and human hepatocytes before and after exposure to a panel of fluoroquinolone compounds. Comparison of the nave HepG2 cell and PHH transcriptomes revealed a substantial number of basal gene expression differences. When HepG2 cells were dosed with a series of fluoroquinolones, trovafloxacin, which has been associated with human idiosyncratic hepatotoxicity, induced substantially more gene expression changes than the other quinolones, similar to previous observations with PHH. While TVX-treatment resulted in many gene expression differences between HepG2 cells and PHH, there were also a number of TVX-induced commonalities, including genes involved in RNA processing and mitochondrial function. Taken together, these results provide insight for interpretation of results from drug metabolism and toxicity studies conducted with HepG2 cells in lieu of PHH, and could provide further insight into the mechanistic evaluation of TVX-induced hepatotoxicity.
Publication Title
Trovafloxacin-induced gene expression changes in liver-derived in vitro systems: comparison of primary human hepatocytes to HepG2 cells.
Sample Metadata Fields
Sex, Specimen part
View Samples- Rattus norvegicus
- 18 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
In this study we have examined the effect of sub-cytotoxic exposure to aristolochic acids (1.65M) at 6h, 24h and 72h on the whole-genome expression profile in a rat proximal renal tubule cell line (NRK-52E).
Publication Title
Aristolochic acids - Induced transcriptomic responses in rat renal proximal tubule cells in vitro.
Sample Metadata Fields
Cell line, Time
View Samples- Homo sapiens
- 5 Downloadable Samples
- Illumina HiSeq 2500
Description
Viral infection can dramatically alter a cell''s transcriptome. However, these changes have mostly been studied by bulk measurements on many cells. Here we use single-cell mRNA sequencing to examine the transcriptional consequences of influenza virus infection. We find extremely wide cell-to-cell variation in production of viral gene transcripts -- viral transcripts compose less than a percent of total mRNA in many infected cells, but a few cells derive over half their mRNA from virus. Some infected cells fail to express at least one viral gene, and this gene absence partially explains variation in viral transcriptional load. Despite variation in total viral load, the relative abundances of viral mRNAs are fairly consistent across infected cells. Activation of innate immune pathways is rare, but some cellular genes co-vary in abundance with the amount of viral mRNA. Overall, our results highlight the complexity of viral infection at the level of single cells. Overall design: Dataset consists of a total of five single-cell datasets generated using the 10x Genomics Chromium Single Cell 3'' Solution platform. All samples were generated from a tissue culture infection model using A549 cells from ATCC and Influenza A/WSN/1933 virus. Uninfected control sample identically processed. Infected samples were generated from cells infected for 6, 8, and 10 hours with a single replicate at 8 hours.
Publication Title
Extreme heterogeneity of influenza virus infection in single cells.
Sample Metadata Fields
Cell line, Subject
View Samples