Regulation of the DNA damage response and cell cycle progression is critical for maintaining genome integrity. Here we report that in response to DNA damage, COPS5 deubiquitinates and stabilizes PEA15 in an ATM kinase-dependent manner. PEA15 expression oscillates throughout the cell cycle, and the loss of PEA15 accelerates cell cycle progression by activating CDK6 expression via the c-JUN transcription factor. Cells lacking PEA15 exhibit a DNA damage-induced G2/M checkpoint defect due to increased CDC25C activity and consequentially higher CDK1/Cyclin B activity and accordingly have an increased rate of spontaneous mutagenesis. We find that oncogenic RAS inhibits PEA15 expression and ectopic PEA15 expression blocks RAS-mediated transformation, which can be partially rescued by ectopic expression of CDK6. Finally, we show that PEA15 expression is down regulated in colon, breast and lung cancer samples. Collectively, our results demonstrate that tumor suppressor PEA15 is a regulator of genome integrity and is an integral component of the DNA damage response pathway that regulates cell cycle progression, the DNA-damage-induced G2/M checkpoint and cellular transformation.
PEA15 regulates the DNA damage-induced cell cycle checkpoint and oncogene-directed transformation.
Cell lineView Samples
Maintenance and propagation of breast cancer stem cells (BCSCs) is mediated via cytokine and growth factor networks. Direct in vivo linkage between dietary regulation of mammary stem (MaSC)/progenitor cell numbers and protection from breast cancer has not been reported. Here, we investigated the effect of post-weaning intake of soy protein isolate (SPI) relative to the control casein (CAS) diet on the stem/progenitor population and tumor formation in MMTV-Wnt1-Transgenic (Wnt1-Tg) female mice. Gene expression profile of the basal (MaSC-enriched) sub-population in preneoplastic Wnt1-Tg mice demonstrated a stem cell-like expression pattern and markedly suppressed expression of inflammatory cytokines, C-X-C family chemokines, and metastasis-associated genes with dietary SPI exposure.
Dietary suppression of the mammary CD29(hi)CD24(+) epithelial subpopulation and its cytokine/chemokine transcriptional signatures modifies mammary tumor risk in MMTV-Wnt1 transgenic mice.
Specimen partView Samples
To better understand the pathogenesis of acute promyelocytic leukemia (APL, FAB M3 AML), we identified genes that are expressed differently in APL cells compared to other acute myeloid leukemia subtypes, and to normal promyelocytes. Comparative gene expression analysis of 14 M3, 62 other AML (M0, M1, M2 and M4) and 5 enriched normal promyelocyte samples revealed a signature of 1,121 genes that are specifically dysregulated in M3 samples relative to other AML, and that do not simply represent normal promyelocyte expression (M3-specific signature). We used a novel, high throughput digital platform (Nanostring's nCounter system) to evaluate a subset of the most significantly dysregulated genes in 30 AML samples; 33 of 37 evaluable gene expression patterns were validated. In an additional analysis, we selected only genes that are dysregulated in M3 both compared to other AML subtypes, and to purified normal CD34+ cells, promyelocytes, and/or neutrophils, thereby isolating a 478 gene "composite M3 dysregulome". Surprisingly, the expression of only a few of these genes was significantly altered in PR-9 cells after PML-RARA induction, suggesting that most of these genes are not direct targets of PML-RARA. Comparison of the M3-specific signature to our previously described murine APL dysregulome revealed 33 commonly dysregulated genes, including JUN, EGR1, and TNF. Collectively, these results suggest that PML-RARA initiates a transcriptional cascade which generates a unique downstream expression signature in both primary human and mouse APL cells.
High throughput digital quantification of mRNA abundance in primary human acute myeloid leukemia samples.
Sex, RaceView Samples
Studies using yeast have advanced our understanding of both replicative and chronological aging, leading to the discovery of longevity genes that have homologues in higher eukaryotes. Chronological lifespan in yeast is conventionally defined as the lifespan of a non-dividing cell. To date, this parameter has only been estimated under calorically restricted (CR) conditions, mimicked by starvation. Since post-mitotic cells in higher eukaryotes are rarely calorically-restricted, we sought to develop an alternative experimental system where non-dividing yeast would age chronologically, in the presence of excess nutrients. We report here on a system wherein alginate-encapsulated yeast are packed in a pH- and temperature-controlled bioreactor, then continuously fed non-limiting substrate for extended periods of time. We present demographic, physiological and genomic evidence indicating that after ~120 hrs, immobilized cells cease dividing, remain metabolically very active and retain >95% viability for periods of 17 days. Over the same time interval, starved planktonic cells, cultured using the same media, and also controlled for temperature and pH, retained < 1 % viability in both aerobic and anaerobic cultures,. Unlike planktonic yeast, continuously-fed immobilized cells hyper-accumulate glycogen. FACS analysis of SYTOX green-stained yeast confirms that immobilized cells completely arrest within 5 days of culture, and unlike starving planktonic cells, remain free thereafter of replicative stress and are non-apoptotic. This unusual state is supported by a global gene expression profile that is stable over time, repeatable across replicate experiments, and altogether distinct from planktonic cells cultured in the presence and absence of limiting nutrients. DNA expression profiling, performed here for the very first time on immobilized cells, reveals that glycolytic genes and their trans-acting regulatory elements are upregulated, as are genes involved in remodeling the cell wall and resisting stress; by contrast, many genes that promote cell cycle progression and carry out oxidative metabolism are repressed. Stress resistance transcription factor MSN4 and its upstream effector RIM15 are conspicuously upregulated in the immobilized state, suggesting that nutrient-sensing pathways may play a role in cell viability and longevity when yeast are immobilized and placed in prolonged culture under calorically-unrestricted conditions. The cell cycle arrest in the immobilized state is mediated by RIM 15. Over the time-course of our experiments, well-fed, non-diving immobilized cells do not appear to age.
Uncoupling reproduction from metabolism extends chronological lifespan in yeast.
No sample metadata fieldsView Samples
Diffuse intrinsic pontine glioma (DIPG) is a universally fatal malignancy of the childhood central nervous system, with a median overall survival of 9-11 months. We have previously shown that primary DIPG tissue contains numerous tumor-associated macrophages, and substantial work has demonstrated a significant pathological role for adult glioma-associated macrophages. However, work over the past decade has highlighted many molecular and genomic differences between pediatric and adult glioblastomas (GBM). Thus, we directly compared inflammatory characteristics of DIPG and adult GBM. We found that the leukocyte (CD45+) compartment in primary DIPG tissue samples is predominantly composed of CD11b+ macrophages, with very few CD3+ T-lymphocytes. In contrast, T-lymphocytes are more abundant in adult GBM tissue samples. RNA sequencing of macrophages isolated from primary tumor samples revealed that DIPG- and adult GBM-associated macrophages both express gene programs related to ECM remodeling and angiogenesis, but DIPG-associated macrophages express substantially fewer inflammatory factors than their adult GBM counterparts. Examining the secretome of glioma cells, we found that patient-derived DIPG cell cultures secrete markedly fewer cytokines and chemokines than patient-derived adult GBM cultures. Concordantly, bulk and single-cell RNA sequencing data indicates low to absent expression of chemokines and cytokines in DIPG. Together, these observations suggest that the inflammatory milieu of the DIPG tumor microenvironment is fundamentally different than adult GBM. The low intrinsic inflammatory signature of DIPG cells may contribute to the lack of lymphocytes and non-inflammatory phenotype of DIPG-associated microglia/macrophages. Understanding the glioma subtype-specific inflammatory milieu may inform the design and application of immunotherapy-based treatments. Overall design: RNA-seq of primary isolated microglia/macrophages from early post-mortem DIPG tissue samples, pediatric normal cortex, and adult GBM tissue samples. Libraries were sequenced on Illumina NextSeq 500, 1x75.
Non-inflammatory tumor microenvironment of diffuse intrinsic pontine glioma.
Sex, Specimen part, SubjectView Samples
Inhibin knockout (Inha-/-) female mice develop sex cord-stromal ovarian cancer with complete penetrance and previous studies demonstrate that the pituitary gonadotropins [follicle stimulating hormone (FSH) and luteinizing hormone (LH)] are influential modifiers of granulosa cell tumor development and progression in inhibin-deficient females. Recent studies have demonstrated that Inha-/- ovarian follicles develop precociously to the early antral stage in prepubertal mice without any increase in serum FSH and these studies suggested that in the absence of inhibins, granulosa cells differentiate abnormally, and thus at sexual maturity may undergo an abnormal response to gonadotropin signaling. To test this hypothesis, we stimulated immature WT and Inha-/- female mice prior to gross tumor formation with gonadotropin analogs, and subsequently examined post-gonadotropin induced ovarian follicle development, as well as preovulatory and hCG-induced gene expression changes in granulosa cells. We find that at three weeks of age, inhibin-deficient ovaries do not show further antral development nor undergo cumulus expansion. Widespread alterations in the transcriptome of gonadotropin-treated Inha-/- granulosa cells suggest that gonadotropins initiate an improper program of cell differentiation in Inha-/- cells. Overall, our experiments reveal that inhibins are essential for the normal gonadotropin-dependent response of granulosa cells.
Defective gonadotropin-dependent ovarian folliculogenesis and granulosa cell gene expression in inhibin-deficient mice.
Specimen part, TreatmentView Samples
Specific pathogen free wild-type C57Bl/6 male mice fed ketogenic diet (Bio-Serv AIN-76-A) for 4 weeks
Adaptation of myocardial substrate metabolism to a ketogenic nutrient environment.
Sex, Specimen partView Samples
We examined transcriptome-wide effects of pertrurbation in KLF10 function (siKLF10) on TGFß-regulated genes and EMT in two different cells lines: A549 and Panc1. Overall design: We performed mRNA sequencing from A549 and Panc1 cells following following TGFß treatment and KLF10 knockdown. The mRNA-Seq includes following conditions: siControl, siKLF10, TGFß, siKLF10+TGFß (A549 and Panc1 cells). mRNA-sequencing was performed in duplicates for A549 and triplicates for Panc1 cells.
Krüppel-like Transcription Factor KLF10 Suppresses TGFβ-Induced Epithelial-to-Mesenchymal Transition via a Negative Feedback Mechanism.
Cell line, SubjectView Samples
Phosphorylation and subsequent nuclear translocation of SMAD proteins determine the cellular response to activin. Here we identify a novel means by which activin signalling is regulated to enable developmental stage-specific SMAD gene transcription. In response to activin A, immature proliferating mouse Sertoli cells exhibit nuclear accumulation of SMAD3, but not SMAD2, although both proteins are phosphorylated. In post-mitotic differentiating cells, both SMAD2 and SMAD3 accumulate in the nucleus. Furthermore, immature Sertoli cells are sensitive to activin dosage; at higher concentrations maximal SMAD3 nuclear accumulation is observed, accompanied by a small, but significant, increase in nuclear SMAD2. Microarray analysis confirmed that differential SMAD utilization correlated with altered transcriptional outcomes and identified new activin target genes, Gja1 and Serpina5, which are known to be required for Sertoli cell development and male fertility. In immature Sertoli cells, genetic or transient knockdown of SMAD3 enhanced SMAD2 nuclear accumulation in response to activin, with increased Serpina5 mRNA levels associated with nuclear localized SMAD2. In transgenic mice with altered activin bioactivity that display male fertility phenotypes, testicular Gja1 and Serpina5 mRNA levels reflected altered in vivo activin levels. We conclude that regulated nuclear accumulation of phosphorylated SMAD2 is a novel determinant of developmentally regulated activin signalling.
Developmentally regulated SMAD2 and SMAD3 utilization directs activin signaling outcomes.
No sample metadata fieldsView Samples
Purpose: RNA-Seq analysis can help identify large set of differentially expressed genes at a time. We performed RNA-Seq analysis to identify differentially expressed genes in the PBMCs of war veterans suffering from PTSD. Methods: Total RNA from PBMCs from PTSD +ve and -ve individuals were used for RNA-Seq analysis. Results: We obtained, on average, ~60 millions reads per sample. More than 70% of the reads were mapped to human genome. Functional analysis of the differentially expressed genes (362) revealed dysregulation in immune system network. Conclusions: Our present study provides further proof that immune system related genes and pathways are dysregulated in PTSD PBMCs. Overall design: RNA-Seq was performed with RNA from 5 each control and PTSD individuals. PBMCs collected within one hour of blood draw were used for RNA isolation. 1 ug of total RNA was used for library synthesis and sequenced in a HighSeq 2000 illumina instrument at Tufts University.
Decreased AGO2 and DCR1 in PBMCs from War Veterans with PTSD leads to diminished miRNA resulting in elevated inflammation.
Specimen part, SubjectView Samples