The retinoblastoma tumor suppressor protein (Rb) regulates early G1 phase checkpoints, including the DNA damage response, as well as cell cycle exit and differentiation. The widely accepted model of G1 cell cycle progression proposes that cyclin D:Cdk4/6 partially inactivates the Rb tumor suppressor during early G1 phase by progressive multi-phosphorylation, termed hypo-phosphorylation, resulting in release of E2F transcription factors. However, this model remains largely unproven biochemically and the biologically active form(s) of Rb remains unknown. Here we find that Rb is un-phosphorylated in G0 cells and becomes exclusively mono-phosphorylated throughout all of early G1 phase by cyclin D:Cdk4/6. Early G1 phase mono-phosphorylated Rb is composed of 14 independent isoforms that are all targeted by the E1a oncoprotein, but each shows a preferential binding pattern to specific E2F1-4 transcription factors. At the late G1 Restriction Point, cyclin E:Cdk2 inactivates Rb by a quantum hyper-phosphorylation (>12 phosphates/Rb). Cells undergoing a DNA damage response activate cyclin D:Cdk4/6 to generate mono-phosphorylated Rb that regulates global transcription. In contrast, a non-phosphorylatable ?Cdk-Rb allele was non-functional for regulating a DNA damage response, but functional for driving cell cycle exit and differentiation during myogenesis. These observations fundamentally change our understanding of G1 cell cycle progression and show that there is no progressive multi-phosphorylation or hypo-phosphorylation inactivation of Rb during early G1 phase by cyclin D:Cdk4/6. Instead, cyclin D:Cdk4/6 generates functionally active, mono-phosphorylated Rb that is the only Rb isoform present in cells during early G1 phase.
Cyclin D activates the Rb tumor suppressor by mono-phosphorylation.
Specimen part
View SamplesAims: Hypertension poses a significant challenge to vasculature homeostasis and stands as the most common cardiovascular disease in the world. Its effects are especially profound on vasculature-lining endothelial cells that are directly exposed to the effects of excess pressure. Here, we characterize the in vivo transcriptomic response of cardiac endothelial cells to hypertension using the spontaneous hypertension mouse model BPH/2J. Methods and results: Verification of defective endothelial function in the BPH/2J hypertensive mouse strain was followed by acute isolation of cardiac endothelial cells and transcriptional profiling using RNA sequencing. Gene profiles from normotensive BPN/3J mice were compared to hypertensive animals. We observed over 3000 transcriptional differences between groups including pathways consistent with the cardiac fibrosis found in hypertensive animals. Importantly, many of the fibrosis-linked genes also differ between juvenile pre-hypertensive and adult hypertensive BPH/2J mice, suggesting that these transcriptional differences are hypertension-related. We also show that blood pressure normalization with amlodipine resulted in a subset of genes reversing their expression pattern, supporting the hypertension-dependency of altered gene expression. Yet, other transcripts were recalcitrant to therapeutic intervention illuminating the possibility that hypertension may irreversibly alter some endothelial transcriptional patterns. Conclusions: Hypertension has a profound effect on both function and transcription of endothelial cells, the latter of which was only partially restored with normalization of blood pressure. This study represents one of the first to quantify how endothelial cells are reprogrammed at the molecular level in cardiovascular pathology and advances our understanding of the transcriptional events associated with endothelial dysfunction. Overall design: Endothelium from hypertensive mice were acutely extracted at two different ages (4 weeks and 22 weeks) and compared to endothelium from 22 week old normotensive mice.
Endothelial transcriptomics reveals activation of fibrosis-related pathways in hypertension.
Age, Cell line, Subject
View SamplesIn this study we could show that the treatment of primary murine prostate cancer(PCa) cells derived from the well-established TRAMP (transgenic adenocarcinoma ofmouse prostate) model with the histone deacetylase inhibitor (HDI) valproic acid (VPA) has an anti-proliferative, anti-migrative and anti-invasive effect on the cells.To our knowledge this is the first study that identified that treatment of PCa cells with VPA leads to the re-expression of cyclin D2, which is known to be frequently inactive in patients with PCa. Additionally, we could demonstrate that VPA specifically induces re-expression of cyclin D2 as a family member of the highly conserved Dtype cyclins in human colorectal and mammary gland adenocarcinoma cell lines, whereas VPA treatment has no effect in NIH/3T3 fibroblasts. The observed cyclin D2 re-expression in cancer cells is activated by an increase of histone acetylation in the promoter region of the cyclin D2 gene and might be the underlying molecular mechanism of the inhibition of proliferation of cancer cells after VPA treatment. Taken together, our results confirm VPA as an anticancer therapeutic option in tumors with epigenetically repressed cyclin D2 expression.
Valproic acid inhibits the proliferation of cancer cells by re-expressing cyclin D2.
Specimen part
View SamplesWe generated primary cultures from renal cell carcinoma and matched normal primary kidney cortex tubule cell cultures from 3 patients. Early passage cultures of these two cell types were subjected to chromatin accessibility profiling (DNase-seq) and gene expression profiling (RNA-seq). Studying these paired and patient-matched controlled data sets will shed light on the epigenomic changes that underlie transformation of kidney tubules into malignant cancers. Overall design: Paired DNase-seq and RNA-seq data sets from 2 different primary human kidney cell types (normal and cancer) Note from submitter: The HIM23 samples have a more narrow consent and their raw data will be submitted to dbGaP.
Integrated epigenomic profiling reveals endogenous retrovirus reactivation in renal cell carcinoma.
Sex, Age, Cell line, Subject
View SamplesIncreasing alpha 7 beta 1-integrin promotes muscle cell proliferation, adhesion, and resistance to apoptosis without changing gene expression.
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View SamplesAnalysis of integrin alpha7 transgenic mice skeletal muscle transcription profiles comparing to wild type controls. Integrin alpha7 is the major laminin binding integrin in muscle cells. Enhancing its expression has been demonstrated to alleviate pathology in a murine model of Duchenne muscular dystrophy. Results of this study provide insights into the effects of increasing integrin alpha7 expression on skeletal muscle transcription and physiology in vivo. This analysis also evaluates any potential possible side effects associate with enhancing integrin alpha7 in skeletal muscle.
Increasing alpha 7 beta 1-integrin promotes muscle cell proliferation, adhesion, and resistance to apoptosis without changing gene expression.
Sex, Age, Specimen part
View SamplesAndrogens are a prequisite for the development of human prostate and prostate cancer. Androgen action is mediated via androgen receptor. Androgen ablation therapy is used for the treatment of metastasized prostate cancer. The aim of the study was to identify genes differentially expressed in benign human prostate, prostate cancer and in prostate tissue three days after castration. These genes are potential diagnostic and therapeutic targets for prostate cancer and benign prostatic hyperplasia.
Identification of androgen-regulated genes in human prostate.
Specimen part, Disease, Treatment
View SamplesMonastrol treatment of Leishmania donovani infected macrophages
A member of the Ras oncogene family, RAP1A, mediates antileishmanial activity of monastrol.
Specimen part, Disease, Treatment
View SamplesTwo high throughput transcript sequencing methods, Digital Gene Expression (DGE) Tag Profiling and RNA-Seq, were used to compare the transcriptional profiles in wild-type (cv. Clark standard, CS) and a mutant (cv. Clark glabrous, i.e., trichomeless or hairless, CG) soybean isoline that carries the dominant P1 allele. DGE data and RNA-Seq data were mapped to the cDNAs (Glyma models) predicted from the reference soybean genome, Williams 82. Extending the model length by 250 bp at both ends resulted in significantly more matches of authentic DGE tags indicating that many of the predicted gene models are prematurely truncated at the 5' and 3' UTRs. The genome-wide comparative study of the transcript profiles of the wild-type versus mutant line revealed a number of differentially expressed genes. One highly-expressed gene, Glyma04g35130, in wild-type soybean was of interest as it has high homology to the cotton gene GhRDL1 gene that has been identified as being involved in cotton fiber initiation and is a member of the BURP protein family. Sequence comparison of Glyma04g35130 among Williams 82 with our sequences derived from CS and CG isolines revealed various SNPs and indels including addition of one nucleotide C in the CG and insertion of ~60 bp in the third exon of CS that causes a frameshift mutation and premature truncation of peptides in both lines as compared to Williams 82. Overall design: 2 samples examined: Clark standard (wild type) and Clark glabrous (soybean hairless mutant)
Transcript profiling reveals expression differences in wild-type and glabrous soybean lines.
Specimen part, Subject
View SamplesHuman adenovirus 5 encodes a small set of miRNAs, which are generated by DICER-mediated processing of 2 larger precursors, the so-called virus-associated RNAs I and II. To identify targets of one of the major miRNA isoforms derived from virus-associated RNAI (mivaRNAI-137), we isolated Argonaute complexes of mivaRNAI-137-transfected cells and analyzed co-purifying RNAs by microarray analysis. RNAs enriched in Argonaute complexes of mivaRNAI-137-transfected cells compared to cells transfected with a control siRNA were identified and subjected to further validation. RNAs specifically associated with Argonaute-containining complexes of adenovirus 5-infected cells were identified as well.
Identification of RISC-associated adenoviral microRNAs, a subset of their direct targets, and global changes in the targetome upon lytic adenovirus 5 infection.
Cell line
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