Constitutive activation of the Wnt pathway leads to adenoma formation, an obligatory step towards intestinal cancer. In view of the established role of Wnt in regulating stemness, we attempted the isolation of cancer stem cells (CSCs) from Apc- and Apc/KRAS-mutant intestinal tumours. Whereas CSCs are present in malignant Apc/KRASmutant carcinomas, they appear to be very rare (<10-6) in the benign Apcmutant adenomas. In contrast, the Lin-CD24hiCD29+ subpopulation of adenocarcinoma cells appear to be enriched in CSCs with increased levels of active -catenin. Expression profiling analysis of the CSC-enriched subpopulation confirmed their enhanced Wnt activity and revealed additional differential expression of other signalling pathways, growth factor binding proteins, and extracellular matrix components. As expected, genes characteristic of the Paneth cell lineage (e.g. defensins) are co-expressed together with stem cell genes (e.g. Lgr5) within the CSC-enriched subpopulation. This is of interest as it may indicate a cancer stem cell niche role for tumor-derived Paneth-like cells, similar to their role in supporting Lgr5+ stem cells in the normal intestinal crypt. Overall, our results indicate that oncogenic KRAS activation in Apc-driven tumours results in the expansion of the CSCs compartment by increasing b-catenin intracellular stabilization.
Cancer stemness in Apc- vs. Apc/KRAS-driven intestinal tumorigenesis.
Specimen part
View SamplesNIH-3T3 cells were pretreated for 15 min with either DMSO (mock) or cycloheximide followed by addition of either mock, 100 U/ml IFNalpha or 100 U/ml IFNgamma for 1h. During the last 30 min, 500 M 4-thiouridine was added to cell culture medium. Total cellular RNA was isolated using Trizol reagent and nascent RNA was purified as described (Dlken et al. RNA 2008) . Three replicates of nascent RNA were analyzed by Affymetrix Mouse Gene ST 1.0 arrays
Deciphering the modulation of gene expression by type I and II interferons combining 4sU-tagging, translational arrest and in silico promoter analysis.
Cell line
View SamplesBALB/c mice are susceptible to proteoglycan (PG) aggrecan-induced arthritis (PGIA), and the absence of TSG-6 further increases susceptibility and local inflammatory reactions, including neutrophil invasion into the joints. To gain insight into the mechanisms of TSG-6 action, synovial fibroblasts were isolated from wild-type and TSG-6-KO mice, cultured and exposed to various agents affecting either the TSG-6 expression and/or modify the intracellular function of TSG-6.
TSG-6 protein, a negative regulator of inflammatory arthritis, forms a ternary complex with murine mast cell tryptases and heparin.
Sex, Treatment
View SamplesRecent studies have reported that glycosphingolipids (GSL) might be involved in obesity induced insulin resistance. Those reports suggested that inhibition of GSL biosynthesis in animals ameliorated insulin sensitivity accompanied with improved glycemic control leading to decreased liver steatosis in obese mice. In addition, GSL depletion altered hepatic secretory function. In those studies, ubiquitously acting inhibitors for GSL-biosynthesis have been used to inhibit function of the enzyme Ugcg (UDP-glucose:ceramide glucosyltransferase), catalyzing the first step of the glucosylceramide based GSL-synthesis pathway. In the present study, a genetic approach for GSL deletion in hepatocytes was chosen to achieve full inhibition of GSL synthesis and to prevent possible adverse effects caused by Ugcg-inhibitors. Using the Cre/loxP system under control of the albumin promoter, GSL biosynthesis in hepatocytes and their release into the plasma could be effectively blocked. Deletion of GSL in hepatocytes did not change quantity of bile excretion through the biliary duct. Total bile salt content in bile-, feces- and plasma from mutant mice showed no difference as compared to control animals. Cholesterol concentration in liver-, bile-, feces- and plasma-samples remained unaffected. Lipoprotein concentration in plasma-samples in mutant animals reached similar levels as in their control littermates. No alteration in glucose tolerance after intraperitoneal application of glucose and insulin appeared in mutant animals. A preventive effect of GSL-deficiency on development of liver steatosis after high fat diet feeding could not be observed.
Hepatic glycosphingolipid deficiency and liver function in mice.
No sample metadata fields
View SamplesmicroRNA miR-144/451 is highly expressed during erythropoiesis. We deleted the miR-144/451 gene locus in mice and compared the transcriptomes of miR-144/451-null bone marrow erythroid precursors to stage-matched wild-type control cells.
miR-451 protects against erythroid oxidant stress by repressing 14-3-3zeta.
Specimen part
View SamplesHuman Immunodeficiency Virus (HIV) associated nephropathy (HIVAN) is characterized clinically by both nephrosis and by rapidly progressive kidney dysfunction. HIVAN is characterized histologically by both collapsing focal segmental glomerulosclerosis and prominent tubular damage. Neutrophil Gelatinase Associated Lipocalin (NGAL) is known to be rapidly expressed in distal segments of the nephron at the onset of different types of acute kidney injury, but few studies have examined NGAL in chronic kidney disease models. We found that urinary NGAL (uNGAL) was highly expressed by patients with biopsy proven HIVAN, whereas HIV+ patients without HIVAN demonstrated lower levels. uNGAL was also highly expressed in the TgFVB mouse model of HIVAN, which demonstrated NGAL gene expression in dilated, microcystic segments of the nephron. These data show that NGAL is markedly upregulated in the setting of HIVAN, and suggest that uNGAL levels may provide a non-invasive screening test to detect HIVAN related tubular disease.
Urinary NGAL marks cystic disease in HIV-associated nephropathy.
No sample metadata fields
View Samples