MicroRNAs predominantly decrease gene expression; however, specific mRNAs are translationally upregulated in quiescent (G0) mammalian cells and immature Xenopus laevis oocytes by an FXR1a-associated microRNP (microRNA-protein complex) that lacks the microRNP repressor, GW182. We conducted global proteomic analysis in THP1 cells depleted of FXR1 to globally identify activation targets of more than one microRNA, since FXR1 is required for microRNAmediated translation activation in THP1 G0 cells by FXR1-microRNPs.Since proteomic data changes could also be due to changes at the RNA level, total RNA levels in FXR1knockdown compared to control shRNA cells were examined in parallel by microarray analysis using Affymetrix Human GeneChip 2.0 ST.
A Specialized Mechanism of Translation Mediated by FXR1a-Associated MicroRNP in Cellular Quiescence.
Specimen part, Cell line
View SamplesThe 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. Overall design: Examination of mRNA levels in pancreatic ductal adenocarcinoma (PDA) cell line 8988T after treatment with siRNA for control or TFE3
Transcriptional control of autophagy-lysosome function drives pancreatic cancer metabolism.
No sample metadata fields
View SamplesEMT, Epithelial to mesenchymal transition is a developmental biology process associated with migration, known to be involved in cancer metastasis. To study this process, we used the breast epithelial cell line MCF10A that enter in EMT after treatment with the cytokine TGFB or by expression of EMT transcriptor factor SNAIL. Overall design: mRNA profiles of MCF10A cells treated for 1 or 6 days with TGFb (done in duplicate), and mRNA profiles of Snail inducible line, MCF10A-SNAIl, induced for 1 or 6 days.
Genomic Instability Is Induced by Persistent Proliferation of Cells Undergoing Epithelial-to-Mesenchymal Transition.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells.
Specimen part, Cell line, Treatment
View SamplesQuiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. We induced chemoresistant and quiescent (G0) leukemic cells by serum-starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the up-regulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα—prior to or along with chemotherapy—substantially reduced chemoresistance in primary leukemic cells ex vivo and in vivo. These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE bearing mRNAs that promote chemoresistance. By disrupting this pathway, we developed an effective combination therapy against chemosurvival.
A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells.
Cell line, Treatment
View SamplesQuiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. We induced chemoresistant and quiescent (G0) leukemic cells by serum-starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the up-regulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα—prior to or along with chemotherapy—substantially reduced chemoresistance in primary leukemic cells ex vivo and in vivo. These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE bearing mRNAs that promote chemoresistance. By disrupting this pathway, we developed an effective combination therapy against chemosurvival.
A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells.
Specimen part, Treatment
View SamplesMolecular mechanisms that are responsible for the development of human skin epithelial cells are not completely understood so far. As a consequence, the efficiency to establish a pure skin epithelial cell population from human induced pluripotent stem cells (hiPSC) remains poor. Using an approach including RNA interference and high-throughput imaging of early epithelial cells, we could identify candidate kinases which are involved in skin epithelial differentiation. Among them, we found HIPK4 to be an important inhibitor of this process. Indeed, its silencing increased the amount of generated skin epithelial precursors, increased the amount of generated keratinocytes and improved growth and differentiation of organotypic cultures, allowing for the formation of a denser basal layer and stratification with the expression of several keratins. Our data bring substantial input in the regulation of human skin epithelial differentiation and for improving differentiation protocols from pluripotent stem cells.
An RNAi Screen Reveals an Essential Role for HIPK4 in Human Skin Epithelial Differentiation from iPSCs.
Specimen part, Time
View SamplesWe used microarrays to establish whether EBF1 and Pax5 repress similar or unique genes. We found that EBF1 uniquely represses the expression of the T-lineage transcription factor Gata3.
Transcriptional repression of Gata3 is essential for early B cell commitment.
Specimen part
View SamplesTo understand the interplay between cancer and stroma, we performed single cell RNA-sequencing of PDAC cells admixed with stromal fibroblasts and defined different single cell populations with varying levels of proliferative and metastatic transcriptional states. PDAC cell behavior in vitro and in vivo on these phenotypic axes could be tuned with the proportion of stromal fibroblasts. These cell types were identified in human pancreatic tumors, and specific subpopulations were associated with worsened outcomes. Overall design: 92 single PDAC cells and 92 single CAF cells were micromanipulated and prepared for sequencing (23 of each cell type from four culture ratios). The 24th sample from each cell type-culture condition combination is a population control obtained by micromanipulating 100 cells of the given type from the given culture condition and preparing it as if it were a single cell, giving a total of 96 PDAC samples and 96 CAF samples. During the course of library construction, 3 samples were lost, all PDAC cells from the 30:70 condition (two single cells and the population control), leaving 93 total PDAC samples and 96 total CAF samples.
Stromal Microenvironment Shapes the Intratumoral Architecture of Pancreatic Cancer.
Specimen part, Subject
View SamplesLung alveolarization is a complex process that involves interactions between several cell types and leads to considerable increase in gas-exchange surface area. The step designated secondary septation includes elastogenesis from interstitial fibroblasts.
Gene expression profiling in lung fibroblasts reveals new players in alveolarization.
No sample metadata fields
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