Project description:In this study we aimed to gain further insight on the role of GCs in adipocyte differentiation. For the future drugability of candidate targets it is of utmost importance to find factors relevant to human biology. Thus, we analyzed the transcriptome of GC induced primary human adipose stem cells (hASC) to identify novel factors downstream of GC action We used microarrays to detail the global programme of gene expression following glucocorticoid treatment and identified distinct classes of up- and downregulated genes during this process. Human preadipocytes (human adipose stem cells) were obtained from lipoaspirates by enzamytic digestions, followed by several steps of centrifugations (Mikkelsen et. al Cell. 2010 Oct 1;143(1):156-69.). Following isolation, human adipose stem cells were transfected with a control siRNA (siCtrl) or two different siRNA oligos targeting the gene LMO3 (siLMO3_oligo1 or siLMO3_oligo2). 40Hrs later, the transfected human adipose stem cells were induced to differentiate into mature adipocytes with a adipogenic cocktail (FullMix) and RNA isolated at day 0 or day6 after induction of differentiation.
Project description:In this study, we aimed to gain further insight on the role of glucocorticoids (GCs) in adipocyte differentiation. For the future drugability of candidate targets, it is of utmost importance to find factors relevant to human biology. Thus, we analyzed the transcriptome of GC-induced primary human adipose stem cells (hASCs) isolated from paired subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) to identify novel factors downstream of GC action. We used microarrays to detail the global program of gene expression following GC treatment and identified distinct classes of up- and down-regulated genes during this process. Human preadipocytes (human adipose stem cells) were obtained from lipoaspirates or visceral fat biopsies by enzymatic digestions, followed by several steps of centrifugations (Mikkelsen et. al Cell. 2010 Oct 1;143(1):156-69.). Following isolation, human adipose stem cells were transfected with either siCtrl or siLMO3 oligonucleotides, followed by treatment with hydrocortisone.
Project description:In this study we aimed to gain further insight on the role of GCs in adipocyte differentiation. For the future drugability of candidate targets it is of utmost importance to find factors relevant to human biology. Thus, we analyzed the transcriptome of GC induced primary human adipose stem cells (hASC) to identify novel factors downstream of GC action We used microarrays to detail the global programme of gene expression following glucocorticoid treatment and identified distinct classes of up- and downregulated genes during this process. Human preadipocytes (human adipose stem cells) were obtained from lipoaspirates by enzamytic digestions, followed by several steps of centrifugations (Mikkelsen et. al Cell. 2010 Oct 1;143(1):156-69.). Following isolation, human adipos estemm cells were treated with Dexamethasone (100nM) for various times.
Project description:The biological functions of nuclear topoisomerase I (Top1) have been difficult to study because knocking out TOP1 is lethal in metazoans. To reveal the functions of human Top1, we have generated stable Top1siRNA cell lines from colon and breast carcinomas (HCT116-siTop1 and MCF-7-siTop1, respectively). In those cells, Top2 compensates for Top1 deficiency. A prominent feature of the siTop1 cells is genomic instability, with chromosomal aberrations and histone gamma-H2AX foci associated with replication. siTop1 cells also show rDNA and nucleolar alterations, and increased nuclear volume. Genome-wide transcription profiling revealed 55 genes with consistent changes in siTop1 cells. Among them, asparagine synthetase (ASNS) was reduced in siTop1 cells, as it also was in cells with transient Top1 downregulation. Conversely, Top1 complementation increased ASNS, indicating a causal link between Top1 and ASNS expression. Correspondingly, pharmacological profiling showed l-asparaginase hypersensitivity in the siTop1 cells. Resistance to camptothecin, aphidicolin, hydroxyurea and staurosporine, and hypersensitivity to etoposide and actinomycin D demonstrated that Top1, in addition to being the target of camptothecins, also regulates DNA replication, rDNA stability and apoptosis. Overall, our studies demonstrate the pleiotropic nature of human Top1 activities. In addition to its classical DNA nicking-closing functions, Top1 plays critical non-classical roles in genomic stability, gene-specific transcription, and response to various anticancer agents. Experiment Overall Design: We are using Affymetrix whole genome array U133 Plus 2, which is a single color microarray platform. For colon experiments, we analyzed 2 different samples as 4 replicates. For breast experiments, we analyzed 2 samples as replicates.
Project description:The transcription factor cMyb plays a key role in human primary CD34+ hematopoietic progenitor cells (HPCs) lineage choice, by enhancing erythropoiesis at the expense of megakaryopoiesis. We previously demonstrated that cMyb affects erythroid versus megakaryocyte lineage decision in part by transactivating KLF1 and LMO2 expression. To further unravel the molecular mechanisms through which cmyb affects lineage fate decision, we profiled the miRNA and mRNA changes in myb-silenced CD34+ HPCs. mRNA and miRNA expression for each sample were profiled by Affymetrix GeneAtlas U219 strip array and Exiqon Human miRNome PCR Panel, respectively. miRNA/mRNA data were integrated by Ingenuity Pathway Analysis. The integrative analysis of miRNA/mRNA expression changes upon c-myb silencing in human CD34+ HPCs highlighted a set of 19 miRNA with 150 anticorrelated putative target mRNAs. Among the miRNAs downregulated in myb-silenced progenitors with the highest number of predicted target mRNAs, we selected hsa-miR-486-3p based on the in vitro effects of its overexpression on HPCs commitment. Indeed, morphological and flow cytometric analyses after liquid culture showed that hsa-miR-486-3p overexpression in HPCs enhanced erythroid and granulocyte differentiation while restraining megakaryocyte and macrophage differentiation. Moreover, collagen-based clonogenic assay demonstrated a strong impairement megakaryocyte commitment upon hsa-miR-486-3p overexpression in CD34+ cells. Gene expression profiling of hsa-miR-486-3p overexpressing CD34+ cells enabled us to identify a set of 8 genes downregulated and computationally predicted, putative hsa-miR-486-3p targets. Among them, we selected c-maf transcript as upregulated upon myb silencing. Worth of note, c-maf silencing in CD34+ progenitor cells was able to reverse the affects of myb silencing on erythroid versus megakaryocyte lineage choice. Integrative miRNA/mRNA analysis highlighted a set of miRNAs and anticorrelated putative target mRNAs modulated upon myb silencing, therefore potential players in myb-driven HPCs lineage choice. Among them, we demonstrated the hsa-miR-486-3p/c-maf pair as partially contributing to the effects of myb on HPCs commitment. Therefore, our data collectively identified myb-driven hsa-miR-486-3p upregulation and subsequent c-maf downregulation as a new molecular mechanism through which cMyb favours erythropoiesis while restraining megakaryopoiesis. RNA from CD34+ HPCs transfected once/twice/3 times with c-myb-targeting/non targeting control siRNAs was collected for a set of 5 independent experiments.
Project description:Endometrial cancer is one of the most common gynecologic malignancies, and patients with high grade disease, especially serous papillary subtype (SPEC) are often related to the poor outcomes. Recent genome-wide analyses have revealed that SPEC exhibits gene expression profiles that are distinct from the endometrioid histologic subtype; therefore, it is important to identify the SPEC driver genes or pathways responsible for the inherently aggressive phenotypes and to develop SPEC-specific therapies to target these driver genes or pathways. Through array-based analysis and immunohistochemical staining of human endometrial cancer tissue, STAT1 is identified high expressed, and can distinguish SPEC from other subtypes of endometrial cancer. In vitro and in vivo experiments show STAT1 role as a pro-survival factor in SPEC. STAT1 was identified as a master gene modulating “transcriptional pro-survival pathways” to enhance multiple malignant characteristics These finding may suggest that targeting of STAT1, the SPEC driver gene, may provide the means to improve poor outcomes for patients with SPEC. We used microarrays to clarify the changes of gene expression along with STAT1-siRNA treatment and to confirm whether there are any changes on genes expression related to STAT1 pathway. We also used the microarray data to clarify genes signatures which can distinguish subtype of human endometrial cancers.
Project description:Adenosine to Inosine (A-to-I) RNA editing is a site-specific modification of RNA transcripts, catalyzed by members of the ADAR (Adenosine Deaminase Acting on RNA) protein family. RNA editing occurs in human RNA in thousands of different sites. Some of the sites are located in protein-coding regions but the majority is found in non-coding regions, such as 3âUTRs, 5âUTRs and introns - mainly in Alu elements. While editing is found in all tissues, the highest levels of editing are found in the brain. It was shown that editing levels within protein-coding regions are increased during embryogenesis and after birth and that RNA editing is crucial for organism viability as well as for normal development. In this study we characterized the A-to-I RNA editing phenomenon during neuronal and spontaneous differentiation of human embryonic stem cells (hESCs). We identified high editing levels of Alu repetitive elements in hESCs and demonstrated a global decrease in editing levels of non-coding Alu sites when hESCs are differentiating, particularly into the neural lineage. Using RNA interference, we showed that the elevated editing levels of Alu elements in undifferentiated hESCs are highly dependent on ADAR1. DNA microarray analysis showed that ADAR1 knockdown has a global effect on gene expression in hESCs and leads to a significant increase in RNA expression levels of genes involved in differentiation and development processes, including neurogenesis. Taken together, our data suggest that A-to-I editing of Alu sequences plays a role in the regulation of hESC early differentiation decisions. Two samples, One control and the second treated
Project description:The activation of cellular quality control pathways to maintain metabolic homeostasis and mitigate diverse cellular stresses is emerging as a critical growth and survival mechanism in many cancers. Autophagy, a highly conserved cellular self-degradative process, is a key player in the initiation and maintenance of pancreatic ductal adenocarcinoma (PDA). However, the regulatory circuits that activate autophagy, and how they enable reprogramming of PDA cell metabolism are unknown. We now show that autophagy regulation in PDA occurs as part of a broader program that coordinates activation of lysosome biogenesis, function and nutrient scavenging, through constitutive activation of the MiT/TFE family of bHLH transcription factors. In PDA cells, the MiT/TFE proteins - MITF, TFE3 and TFEB - override a regulatory mechanism that controls their nuclear translocation, resulting in their constitutive activation. By orchestrating the expression of a coherent network of genes that induce high levels of lysosomal catabolic function, the MiT/TFE factors are required for proliferation and tumorigenicity of PDA cells. Importantly, unbiased global metabolite profiling reveals that MiT/TFE-dependent autophagy-lysosomal activation is specifically required to maintain intracellular AA pools in PDA. This AA flux is part of a program that is essential for metabolic homeostasis and bioenergetics of PDA but not for their non-transformed counterparts. These results identify the MiT/TFE transcription factors as master regulators of the autophagy-lysosomal system in PDA and demonstrate a central role of the autophagosome-lysosome compartment in maintaining tumor cell metabolism through alternative amino acid acquisition and utilization. Examination of mRNA levels in pancreatic ductal adenocarcinoma (PDA) cell line 8988T after treatment with siRNA for control or TFE3
Project description:EZH2 is frequently over-expressed in aggressive and metastatic solid tumors, including castration resistant prostate cancer (CRPC). We sought to determine EZH2-dependent gene expression programmes in prostate cancer progression, and found an intriguing functional switch of EZH2 from a repressor to an activator during CRPC development. We used microarrays to detail the global profiling of gene expression that are differentially regulated upon EZH2 depletion in two different prostate cancer cell lines. The androgen-dependent prostate cancer cell line LNCaP and the LNCaP-derived androgen-independent cell line LNCaP-abl (abl) were used for this study, as their transcription profiles strongly resemble that of clinical androgen-dependent and castration resistant prostate tumors, respectively. EZH2 was silenced by specific siRNAs in both cell lines, and total RNA was extracted and hybridized on Affymetrix microarrays.
Project description:Long non-coding RNAs (lncRNAs) are master regulators of gene expression and have recently emerged as potential innovative therapeutic targets. The deregulation of lncRNA expression patterns has been associated with age-related and noncommunicable diseases, including osteoporosis and bone tumors. However, the specific role of lncRNAs in physiological or pathological conditions in the bone tissue still needs to be further clarified, for their exploitation as therapeutic tools. In the present study, we evaluate the potential of the lncRNA CASC2 as a regulator of osteogenic differentiation and mineralization. Results show that CASC2 expression is decreased during osteogenic differentiation of human bone marrow-derived Mesenchymal Stem/Stromal cells (MSCs). CASC2 knockdown using small interfering RNA (siCASC2) increases the expression of the late osteogenic marker Bone Sialoprotein (BSP), but does not impact ALP staining levels, or the expression of early osteogenic transcripts including RUNX2 and OPG. Although siCASC2 does not impact hMSC proliferation nor apoptosis, it promotes the mineralization of hMSC cultured under osteogenic-inducing conditions, as shown by the increase of calcium deposits. Mass spectrometry-based proteomic analysis revealed that 89 proteins are regulated by CASC2 at late osteogenic stages, including proteins associated with bone diseases or anthropometric and musculoskeletal traits. Specifically, the Cartilage Oligomeric Matrix Protein (COMP) is highly enhanced by CASC2 knockdown at late stages of osteogenic differentiation, at either transcriptional and protein level. Inhibition of COMP impairs osteoblasts mineralization as well as the expression of BSP levels. The results indicate that lncRNA CASC2 regulates late osteogenesis and mineralization in hMSC via COMP and BSP. In conclusion, this study suggests lncRNA CASC2 as a potential new therapeutic target in bone mineralization.