Hepatic iron overload is a risk factor for progression of hepatocellular carcinoma (HCC), although the molecular mechanisms underlying this association have remained unclear. We now show that the iron-sensing ubiquitin ligase FBXL5 is previously unrecognized oncosuppressor in liver carcinogenesis in mice. Hepatocellular iron overload evoked by FBXL5 ablation gives rise to oxidative stress, tissue damage, inflammation and compensatory proliferation in hepatocytes and to consequent promotion of liver carcinogenesis induced by exposure to a chemical carcinogen. The tumor-promoting effect of FBXL5 deficiency in the liver is also operative in a model of virus-induced HCC. FBXL5-deficient mice thus constitute the first genetically engineered mouse model of liver carcinogenesis induced by iron overload. Dysregulation of FBXL5-mediated cellular iron homeostasis was also found to be associated with poor prognosis in human HCC, implicating FBXL5 plays a significant role in defense against hepatocarcinogenesis. Overall design: Total RNA was extracted from the nontumor and tumor tissue of an Alb-Cre/Fbxl5F/F male mouse (nontumor, n = 5; tumor, n = 5) or two littermate control Fbxl5F/F mice (nontumor, n = 6; tumor, n = 6) at 45 weeks of age.
Disruption of FBXL5-mediated cellular iron homeostasis promotes liver carcinogenesis.
Specimen part, Cell line, Subject
View SamplesBehavioral transitions Young infant rats paradoxically prefer odors paired with shock but older pups learn aversions. This transition is amygdala- and corticosterone-dependent.
Transitions in infant learning are modulated by dopamine in the amygdala.
No sample metadata fields
View SamplesWe found that a number of Tfh cells downmodulated BCL6 protein after their development, and we sought to compare the gene expression between BCL6-hi Tfh cells and BCL6-low Tfh cells.
Bcl6 protein expression shapes pre-germinal center B cell dynamics and follicular helper T cell heterogeneity.
Specimen part
View SamplesWe searched for roles of ZEB1 during EMT by RNA-seq in breast cancer cells. Overall design: Expression of mRNA in a basal type breast cancer cell line MDA-231-D transfected with ZEB1/ZEB2 siRNAs and stimulated with TGF-beta for 24 h.
ZEB1-regulated inflammatory phenotype in breast cancer cells.
Specimen part, Cell line, Subject
View SamplesMelanoma resistant to MAPK inhibitors (MAPKi) displays loss of fitness upon experimental MAPKi withdrawal and, clinically, may be resensitized to MAPKi therapy after a drug holiday. Here, we uncovered and therapeutically exploited the mechanisms of MAPKi addiction in MAPKi-resistant BRAF MUT or NRAS MUT melanoma. MAPKi-addiction phenotypes evident upon drug withdrawal spanned transient cell-cycle slowdown to cell-death responses, the latter of which required a robust phosphorylated ERK (pERK) rebound. Generally, drug withdrawal–induced pERK rebound upregulated p38–FRA1–JUNB–CDKN1A and downregulated proliferation, but only a robust pERK rebound resulted in DNA damage and parthanatos-related cell death. Importantly, pharmacologically impairing DNA damage repair during MAPKi withdrawal augmented MAPKi addiction across the board by converting a cell-cycle deceleration to a caspase-dependent cell-death response or by furthering parthanatos related cell death. Specifically in MEKi-resistant NRAS MUT or atypical BRAF MUT melanoma, treatment with a type I RAF inhibitor intensified pERK rebound elicited by MEKi withdrawal, thereby promoting a cell death–predominant MAPKi-addiction phenotype. Thus, MAPKi discontinuation upon disease progression should be coupled with specific strategies that augment MAPKi addiction. Overall design: BRAF/MEK inhibitors resistant cell lines M249DDR5 and SKMEL28DDR1 were assayed for their responses after 6 hr of BRAF/MEK inhibitor treatment and after inhibitors withdrawal (by washin) for 6 and 24 hours
Exploiting Drug Addiction Mechanisms to Select against MAPKi-Resistant Melanoma.
Cell line, Subject
View SamplesCharacterization of bacterial behavior in the microgravity environment of spaceflight is of importance towards risk assessment and prevention of infectious disease during long-term missions. Further, this research field unveils new insights into connections between low fluid-shear regions encountered by pathogens during their natural infection process in vivo, and bacterial virulence. This study is the first to characterize the global transcriptomic and proteomic response of an opportunistic pathogen that is actually found in the space habitat, Pseudomonas aeruginosa. Overall, P. aeruginosa responded to spaceflight conditions through differential regulation of 167 genes and 28 proteins, with Hfq identified as a global transcriptional regulator in the response to this environment. Since Hfq was also induced in spaceflight-grown Salmonella typhimurium, Hfq represents the first spaceflight-induced regulator across the bacterial species border. The major P. aeruginosa virulence-related genes induced in spaceflight conditions were the lecA and lecB lectins and the rhamnosyltransferase (rhlA), involved in the production of rhamnolipids. The transcriptional response of spaceflight-grown P. aeruginosa was compared with our previous data of this organism grown in microgravity-analogue conditions using the rotating wall vessel (RWV) bioreactor technology. Interesting similarities were observed, among others with regard to Hfq regulation and oxygen utilization. While LSMMG-grown P. aeruginosa mainly induced genes involved in microaerophilic metabolism, P. aeruginosa cultured in spaceflight adopted an anaerobic mode of growth, in which denitrification was presumably most prominent. Differences in hardware between spaceflight and LSMMG experiments, in combination with more pronounced low fluid shear and mixing in spaceflight when compared to LSMMG conditions, were hypothesized to be at the origin of these observations. Collectively, our data suggest that spaceflight conditions could induce the transition of P. aeruginosa from an opportunistic organism to potential pathogen, results that are of importance for infectious disease risk assessment and prevention, both during spaceflight missions and in the clinic.
Transcriptional and proteomic responses of Pseudomonas aeruginosa PAO1 to spaceflight conditions involve Hfq regulation and reveal a role for oxygen.
No sample metadata fields
View SamplesAngiogenesis in cultures of rat aorta begins with neovessels sprouting from the aortic explant within the first three days of culture.
Macrophage-derived tumor necrosis factor-alpha is an early component of the molecular cascade leading to angiogenesis in response to aortic injury.
Sex, Specimen part, Treatment
View SamplesAngiogenesis in collagen gel cultures of rat aorta begins with neovessels sprouting from the aortic explant within the first three days of culture.
Macrophage-derived tumor necrosis factor-alpha is an early component of the molecular cascade leading to angiogenesis in response to aortic injury.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Non-genomic and Immune Evolution of Melanoma Acquiring MAPKi Resistance.
Specimen part
View SamplesMelanoma resistance to MAPK- or T cell checkpoint-targeted therapies represents a major clinical challenge, and treatment failures of MAPK-targeted therapies due to acquired resistance often require salvage immunotherapies. We show that genomic analysis of acquired resistance to MAPK inhibitors revealed key driver genes but failedto adequately account for clinical resistance. From a large-scale comparative analysis of temporal transcriptomes from patient-matched tumor biopsies, we discovered highly recurrent differential expression and signature outputs of c-MET, LEF1 and YAP1 as drivers of acquired MAPK inhibitor resistance. Moreover, integration of gene- and signature-based transcriptomic analysis revealed profound CD8 T cell deficiency detected in half of resistant melanomas in association with downregulation of dendritic cells and antigen presentation. We also propose a major methylomic basis to transcriptomic evolution under MAPK inhibitor selection. Thus, this database provides a rich informational resource, and the current landscape represents a benchmark to understanding melanoma therapeutic resistance. Overall design: Melanoma biopsies pre and post MAPKi treatment were sent for RNAseq analysis
Non-genomic and Immune Evolution of Melanoma Acquiring MAPKi Resistance.
No sample metadata fields
View Samples