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Adenosine phosphorylase (EC 2.4.2.-) activity present in Sarcoma 180 cells grown in culture and in rat liver, is shown to be distinct from inosine-guanosine phosphorylase by several criteria: (a) treatment of Sarcoma 180 cell extract with p-chloromercuribenzoate inhibited the two activities to a
A case of alveolar soft part sarcoma was studied by light and electron microscopy and by electron microscopic enzyme histochemistry of adenosine triphosphatase (ATPase) and 5'nucleotidase(5'Nase). The tumor showed distinct alveolar pattern and diastase resistant PAS positive crystalline inclusions
Di(adenosine-5')oligophosphate nucleotides of general structure ApnA (n = 2-6) inhibited phosphorylation of immunoglobulin G from tumor-bearing rabbits (TBR IgG) by pp60src protein kinase purified from Rous sarcoma virus-transformed rat tumor cells. Ap4A, a nucleotide associated with eukaryotic cell
Sarcoma cells growing in tissue culture have morphological and growth characteristics different than normal fibroblasts. Several of the morphological characteristics of normal fibroblasts are regained when the cells are incubated with dibutyryl-cyclic AMP or butyryl-cyclic AMP (0.1-1 mM), or cyclic
We have investigated the influence of 2',5' adenosine nucleotides on the replication and transformation of cells by Rous sarcoma virus (RSV). Treatment with the nucleotides ppp2',5'A4 and 2',5'A4 causes a striking reduction (50-fold) in the yield of infectious progeny virus, while ppp2',5A2 and
Prostaglandin E1 (2.5 mug/ml) enhanced the level of cyclic adenosine 3':5'-monophosphate (cyclic AMP) three to four times in Yoshida ascites sarcoma (YS) cells cultured in vitro. When Ricinus communis toxin (RC-toxin) was added 30 min after the addition of prostaglandin E1, the enhanced level of
N6-adenosine methylation (m6A) is the most common posttranscriptional RNA modification in mammalian cells. We found that most transcripts encoded by the Kaposi's sarcoma-associated herpesvirus (KSHV) genome undergo m6A modification. The levels of m6A-modified mRNAs increased substantially upon
Ewing's sarcoma (ES) is a highly malignant childhood bone tumor and is considered curable by moderate doses of radiotherapy. The addition of chemical inhibitors of the activity of the nuclear enzyme poly(adenosine diphosphate ribose) [poly(ADPR)] polymerase to ES cells in culture results in
Pretreatment with 10(-8) M retinoic acid for 4 days caused changes in three distinct components of the parathyroid hormone (PTH)-stimulated cyclic adenosine 3':5'-monophosphate response in a clonal rat osteogenic sarcoma cell line, UMR 106-06: the amplitude of the cyclic adenosine
The localization of ATPases in 7 osteogenic sarcomas of osteoblastic, chondroblastic and fibroblastic type was investigated at the fine structural level using two types of substrates: one with lead as capturing ion and one with strontium (the latter presumed to reveal sites of Na+-K+-dependent
ATPase was localized in distinct regions of the mitotic apparatus of HeLa and Sarcoma 180 tissue culture cells. ATPase was demonstrated in the metaphase spindle of HeLa and Sarcoma 180 cells fixed in cold buffered 2 per cent formalin (pH 6.5 to 6.8) containing 2 x 10(-3)M CaCl(2). A high
No detectable adenosine deaminase activity was found in whole cells or 105,000g cytosol preparations of B-mix K-44/6 cells when either [3H]adenosine or [3H]arabinosyladenine was used as substrate. When grown in tissue culture medium supplemented with horse serum these cells provide a deaminase-free
Late passage cultures of a clonal osteogenic sarcoma line (ROS 17/2.8) failed to respond to PTH with activation of cAMP-dependent protein kinase isoenzymes despite showing a sensitive and dose-dependent increase in cAMP after treatment with the hormone. When cells were treated with hydrocortisone or
The growth-inhibitory effect of 6-methylmercaptopurine riboside (MMPR) against leukemia L1210 cells in culture was dramatically potentiated by the addition of guanine nucleosides to the medium. In the presence of either deoxyguanosine or guanosine, the concentration of MMPR that caused 50%
To provide information on the role of nucleases in oncogenic virus infection, the activities of 3'-nucleotide phosphodiesterase (3'-NPDase), 5'-nucleotide phosphodiesterase (5'-NPDase), acid deoxyribonuclease (DNase II), and 3',5'-cyclic AMP phosphodiesterase (cAMPDase) in spleen extracts of murine