Autophagy driven by a master regulator of hematopoiesis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE32491 | GEO | 2011/09/30
SECONDARY ACCESSION(S): PRJNA147759
REPOSITORIES: GEO
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2011-09-30 | E-GEOD-32491 | biostudies-arrayexpress
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2023-09-28 | PXD039959 | Pride
Project description:Renal cancer accounts for 2% to 3% of all adult malignancies in the US. In 2011 more than 64,770 new cases and 13,000 deaths were reported and the incidence is steadily increasing by 2.5% per year. Clear cell renal carcinoma (ccRCC) represents the majority (85% to 90%) of adult kidney cancers and is the most malignant. This cancer is characterized by an early loss of the von Hippel-Lindau tumor suppressor (VHL) on short arm of chromosome 3 in the majority of tumors (80%). It is a classic knowledge that loss of VHL results in an increased accumulation and activity of the hypoxia-inducible transcription factor (HIF), which in turns activates expression of genes promoting tumor growth. In that respect, induction of angiogenic factors induces blood flow through the tumors and delivery of nutrients and oxygen to cancer cells, while induction of genes inducing anaerobic glycolysis supports adaptation to reduced nutrients availability and shifts towards metabolic pathways promoting tumor growth. Recently we have discovered another tumor suppressing pathway regulated by VHL. We found that VHL is a major regulator of the process of macroautophagy (autophagy) (ref). We identified that VHL induces expression of a microRNA, miR-204, which in turn inhibits activity of a major regulator required for the formation of autophagosome, LC3B. LC3B-mediated autophagy is necessary for the ccRCC tumor growth, and inhibition of this process by VHL and miR-204 significantly contributes to the tumor suppression. Most importantly, we discovered that VHL by inhibiting activity of HIF, induced expression and activity of an LC3B paralog, LC3C. In contrast to LC3B, LC3C acts as a tumor suppressor, indicating the specificity and complexity of different autophagic programs. Integrating these novel data with the established role of VHL in regulating angiogenesis produces a more global picture of VHL as a master tumor suppressor that regulates nutrient access for renal cancer cells from both extracellular and intracellular sources. In the process of searching for other genes induced by VHL that could participate in the tumor suppressing activity of VHL, we discovered that reconstitution of VHL in RCC cells induces enrichment of genes expressed from the Smith-Magenis locus (SM), located on the short arm of chromosome 17p11.2. Smith-Magenis syndrome is a complex neurobehevioural disorder, characterized by intellectual impairment, craniofacial and skeletal anomalies and sleep disturbance. Recently, deletions or mutations of one specific gene in the SM locus, RAI1, (retinoic acid induced 1), were shown to be responsible for the syndrome. Interestingly, this locus contains another kidney tumor suppressor gene, folliculin (FLCN), of which activity is lost in the genetic dominant disorder, Birt-Hogg-Dube syndrome (BHD). BHD is characterized by skin fibrofolliculomas, pulmonary cysts and spontaneous pneumothorax, as well as renal cancer of mixed histological types, including chromophobe, oncocytic, clear cell and papillary type. Here we show that VHL regulates expression of FLCN, and in turn FLCN contributes to the VHL-mediated suppression of tumor growth. Two-condition experiment, VHL(-) vs. VHL(+). 4 biological replicates in each group. Two dual-channel arrays with VHL(+) on Cy5 and VHL(-) on Cy3, and two dual-channel arrays with flipped samples.
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2017-10-10 | GSE98523 | GEO
Project description:Enhanced autophagy is recognized as a component of the pathogenesis of smoking-induced airway disease. Based on the knowledge that enhanced autophagy is linked to oxidative stress and the DNA damage response, both of which are linked to smoking, we used microarray analysis of the small airway epithelium to identify smoking up-regulated genes known to re-spond to oxidative stress and the DNA damage response. This analysis identified OSGIN1 as significantly up-regulated by smoking in both the large and small airway epithelium (1.8-fold, p<0.01, 2.1-fold, p<10-4, respectively), an observation confirmed by an independent small airway microarray cohort, TaqMan PCR and RNAseq. Genome-wide correlation of RNAseq analysis of airway basal/progenitor cells isolated from healthy subjects (n=17) showed a direct correlation of OSGIN1 mRNA levels to multiple classic autophagy genes, including, LC3B, P62, WIPI1 and ATG13 (all rho>0.7, p<0.01). In vitro cigarette smoke extract exposure of nonsmoker primary airway basal/progenitor cells was accompanied by a dose-dependent up-regulation of OSGIN1 and autophagy induction. Lentivirus-mediated enhanced expression of OSGIN1 in human primary basal/progenitor cells induced puncta-like staining of LC3B and up-regulation of LC3B mRNA and protein and P62 mRNA expression level in a dose and time-dependent manner. OSGIN1-induction of autophagosome / amphistome / autolysosome formation was confirmed by co-localization of LC3B with P62 or CD63 (endosome marker) and LAMP1 (lysosome marker). Induction of autophagy by OSGIN1 is accompanied with heightened oxidative stress. Together, these observations support the concept that smoking-induced up-regulation of OSGIN1 is at least one link between smoking-induced stress and enhanced-autophagy in the human airway epithelium.
2017-08-31 | GSE76326 | GEO