Intermediary metabolism in the Swarm rat chondrosarcoma chondrocyte.
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ABSTRACT:
SUBMITTER: Spencer CA
PROVIDER: S-EPMC1133720 | biostudies-other | 1990 Feb
REPOSITORIES: biostudies-other
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Project description:UDP-sugars and adenine nucleotides were extracted from freshly isolated chondrocytes and primary cell cultures and analysed by anion-exchange h.p.l.c. The pool sizes of UDP-N-acetylglucosamine, UDP-N-acetylgalactosamine, UDP-glucose-galactose, UDP-glucuronate and UDP-xylose were 2.9, 1.2, 2.5, 0.6 and 0.03 nmol/10(6) freshly isolated chondrocytes. When chondrocytes were maintained in Dulbecco's modified Eagle medium supplemented with 15% foetal-bovine serum, synthesis of [35S]proteoglycan and [3H]protein decreased over the first 48 h in culture, as did the pools of UDP-glucuronate and ATP. In contrast, the size of the UDP-N-acetylhexosamine pools underwent little change during culture. [35S]Proteoglycan and [3H]protein syntheses were stimulated in cultures supplemented with serum or insulin compared with those maintained in medium alone, in agreement with previous results. However, the UDP-sugar pool sizes were the same in both supplemented and non-supplemented cultures. In cultures maintained in the presence of [1-3H]glucose, the UDP-sugars were labelled to a constant 3H specific radioactivity which was very similar to that of the labelling medium. UDP-N-acetylhexosamines were labelled to constant 3H specific radioactivity with [6-3H]glucosamine as a precursor, but only about 1 in 375 of these UDP-sugars was derived from the amino sugar in the presence of glucose. The half-life (t1/2) for UDP-hexoses, UDP-glucuronate and UDP-N-acetylhexosamines was about 12, 12 and 50 min respectively.
| S-EPMC1132311 | biostudies-other
Project description:BackgroundChondrosarcomas are malignant cartilage tumors that do not respond to traditional chemotherapy or radiation. The 5-year survival rate of histologic grade III chondrosarcoma is less than 30%. An animal model of chondrosarcoma has been established--namely, the Swarm Rat Chondrosarcoma (SRC)--and shown to resemble the human disease. Previous studies with this model revealed that tumor microenvironment could significantly influence chondrosarcoma malignancy.MethodsTo examine the effect of the microenvironment, SRC tumors were initiated at different transplantation sites. Pyrosequencing assays were utilized to assess the DNA methylation of the tumors, and SAGE libraries were constructed and sequenced to determine the gene expression profiles of the tumors. Based on the gene expression analysis, subsequent functional assays were designed to determine the relevancy of the specific genes in the development and progression of the SRC.ResultsThe site of transplantation had a significant impact on the epigenetic and gene expression profiles of SRC tumors. Our analyses revealed that SRC tumors were hypomethylated compared to control tissue, and that tumors at each transplantation site had a unique expression profile. Subsequent functional analysis of differentially expressed genes, albeit preliminary, provided some insight into the role that thymosin-?4, c-fos, and CTGF may play in chondrosarcoma development and progression.ConclusionThis report describes the first global molecular characterization of the SRC model, and it demonstrates that the tumor microenvironment can induce epigenetic alterations and changes in gene expression in the SRC tumors. We documented changes in gene expression that accompany changes in tumor phenotype, and these gene expression changes provide insight into the pathways that may play a role in the development and progression of chondrosarcoma. Furthermore, specific functional analysis indicates that thymosin-?4 may have a role in chondrosarcoma metastasis.
| S-EPMC2944175 | biostudies-literature
Project description:The puropose of this experiment was to identify gene expression changes that result from 5-aza-2-deoxycytidine induced DNA demethylation of Swarm rat chondrosarcoma cells. The gene expression profiles of untreated Swarm rat chondrosarcoma cells were compared to the gene expression profiles of Swarm rat chondrosarcoma cells that were treated for 5 passages with a low dose of 5-aza-2-deoxycytidine (0.1uM).
2010-08-06 | GSE17598 | GEO
Project description:Treatment of Swarm rat chondrosarcoma chondrocytes for 3 days in media containing either non-recombinant pig or recombinant human insulin (1 micrograms/ml) increased the rate of proteoglycan synthesis approximately 6-fold compared with cells cultured in the absence of insulin. The concentrations of human and pig insulin that stimulated the cells to double their rate of proteoglycan synthesis were approximately 1 ng/ml and approximately 2 ng/ml respectively. Because physiological concentrations of insulin do not influence proteoglycan synthesis in non-transformed chondrocytes, the findings indicated a possible abnormality in the insulin-dependent regulation of the insulin receptor in these tumour cells. Like most cells, chondrosarcoma chondrocytes down-regulated their insulin receptors when incubated with insulin for 30 min. However, the number of plasma-membrane and intracellular insulin receptors did not decrease when the chondrocytes were exposed to insulin chronically for 4 days. Chondrocytes were cultured in media containing 2H-, 13C- and 15N-labelled amino acids, and the heavy-isotope density-shift method was used to investigate both the rate of degradation and the rate of synthesis of the insulin receptor. Although the rate of synthesis of the receptor was slightly faster in the insulin-treated cultures, as assessed by a slightly faster rate of appearance of the 'heavy' receptor, the rate of degradation of the receptor was slower in the insulin-treated cultures. The half-lives for the 'light' receptors were approx. 18 h and 10 h for chondrocytes cultured in insulin-containing and insulin-free media respectively. These studies in vitro indicate that the apparent up-regulation of insulin receptors that occurs in this transformed cell upon long-term exposure to insulin is primarily the result of a decreased rate of receptor degradation.
| S-EPMC1135057 | biostudies-other
Project description:The puropose of this experiment was to identify gene expression changes that result from 5-aza-2-deoxycytidine induced DNA demethylation of Swarm rat chondrosarcoma cells. The gene expression profiles of untreated Swarm rat chondrosarcoma cells were compared to the gene expression profiles of Swarm rat chondrosarcoma cells that were treated for 5 passages with a low dose of 5-aza-2-deoxycytidine (0.1uM). Five chip study. For these experiments, microarray was carried out on untreated (control) Swarm rat chondrosarcoma cells (3 biological replicates), and microarray was also carried out on Swarm rat chondrosarcoma cells treated with 5-aza-2-deoxycytidine (2 biological replicates).
2010-08-06 | E-GEOD-17598 | biostudies-arrayexpress
Project description:Chondrosarcoma is the second most common type of skeletal malignancy with a survival rate at five years for histological grade III of only 29 percent. The development of a reliable chondrosarcoma animal model could enable the study of tumor growth and progression, the effect of the host on tumor behavior, and the effectiveness of various therapeutic modalities. The Swarm rat chondrosarcoma is a tumor tissue line that has been maintained through the years by serial subcutaneous injections, and the histochemical characteristics of the tumor have remained essentially similar in all transplants over the years. This study was designed to initiate the characterization of the Swarm rat chondrosarcoma model by gene expression profiling as compared to normal-growing rat cartilage. Analysis of the gene expression from both libraries revealed a complex pattern of gene expression, including many genes not yet reported to be expressed by chondrocytes. It suggests that the biochemical characterization of growing cartilage and chondrosarcoma reported to date has only begun to describe the complexity of these tissues.
| S-EPMC1888380 | biostudies-literature
Project description:Synthesis of [3H]hyaluronate from [6-3H]glucosamine was investigated in cultures of Swarm rat chondrosarcoma chondrocytes treated with various concentrations (0.1 microM-0.1 mM) of cycloheximide for various times. Concentrations greater than 1 microM inhibited protein synthesis by greater than 90%. Hyaluronate synthesis was decreased, with a t1/2 for 50% inhibition of 80-120 min, depending on the concentration of cycloheximide present. Similar experiments using [1-3H]glucose as a precursor label gave similar results. Experiments using [6-3H]glucosamine as a precursor label and 0.18 mM-puromycin to inhibit protein synthesis inhibited hyaluronate synthesis (t1/2 = 82 min) with similar kinetics to cycloheximide-induced inhibition. Cultures incubated with 3.6 microM-cycloheximide for up to 9 h and supplemented with p-nitrophenyl beta-D-xyloside during the last 75 min of treatment showed increased synthesis of [3H,35S]chondroitin sulphate, demonstrating that UDP-hexose precursors for glycosaminoglycan synthesis are not rapidly depleted on blockage of protein synthesis. Rapid metabolic turnover of hyaluronate synthetase is the most likely cause for decreased hyaluronate synthesis in chondrocytes in which protein synthesis is inhibited.
| S-EPMC1146870 | biostudies-other
Project description:These libraries represent instances of Swarm rat chondrosarcoma tumors taken from different transplantation experiments. This series also contains one non-cancerous cartilage library made from rat normal growing femoral head cartilage as a comparative data point. Keywords: other
2004-07-24 | GSE1517 | GEO
Project description:These libraries represent instances of Swarm rat chondrosarcoma tumors taken from different transplantation experiments. This series also contains one non-cancerous cartilage library made from rat normal growing femoral head cartilage as a comparative data point. Keywords: other
2004-07-24 | E-GEOD-1517 | biostudies-arrayexpress
Project description:PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damage-regulated gene 1 (PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase II complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.
| S-EPMC5714802 | biostudies-literature