Role of natural prostaglandins in the control of murine mammary tumor virus expression
| Autor: | V. Thurzo, L. Halcak, P. Svec, J. Svec |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Cancer Research
medicine.medical_specialty Adenylate kinase Stimulation Adenocarcinoma Biology Dinoprost Virus Replication Cyclase Dexamethasone Cell Line Mice Mammary tumor virus Internal medicine Cyclic AMP medicine Animals Alprostadil Mice Inbred C3H Prostaglandins A Mammary tumor Prostaglandins B Prostaglandins E Prostaglandins F Mammary Neoplasms Experimental General Medicine Endocrinology Mammary Tumor Virus Mouse Oncology Cell culture Prostaglandins Female Intracellular Glucocorticoid Adenylyl Cyclases medicine.drug |
| Zdroj: | Journal of Cancer Research and Clinical Oncology. 103:55-67 |
| ISSN: | 1432-1335 0171-5216 |
| DOI: | 10.1007/bf00410306 |
| Popis: | The regulation of murine mammary tumor virus (MuMTV) production by mammotropic hormones, hormonomimetic substances, and cyclic nucleotides was investigated. The virus produced in control and treated mammary tumor cell cultures was quantitated by measuring the supernatant reverse transcriptase activity in exogenous reaction using poly(rC).oligo(dG) as template-primer. Two days after exposure, the synthetic glucocorticoid, dexamethasone (DXMT), increased spontaneous MuMTV production at optimal concentration (0.1 mumol) up to ten times. Dibutyryl derivative of cyclic AMP had no effect on spontaneous MuMTV production, whereas the drug potentiated suboptimal concentrations of the glucocorticoid. Natural prostaglandins, potent agonists of adenylate cyclase catalyzing intracellular synthesis of cyclic AMP, enhanced both basal (up to five times) and DXMT-stimulated (up to 1.6 times) MuMTV replication. The MuMTV-stimulating activity of prostaglandins decreased in the order of PGA1 greater than PGE1 greater than PGB1 greater than PGF2 alpha. Prostaglandins can be replaced partially by norepinephrine and isoproterenol by enhancing the DXMT-mediated MuMTV stimulation, whereas these drugs remained without effect on spontaneous MuMTV production. Theophylline, an antagonist of cAMP-phosphodiesterase converting cAMP to AMP, enhanced the virus-stimulating activity of DXMT as well as of prostaglandins. The enhancement of MuMTV production by adenylate cyclase agonists do not correlate absolutely with the estimates of intracellular cAMP levels, since the highest amounts of cAMP has been repeatedly observed in cells treated with PGE1 and norepinephrine. The results indicate that besides hormones, other hormone-like substances and cyclic nucleotides may be involved in the complex mechanism of hormone-regulated MuMTV genome expression. |
| Databáze: | OpenAIRE |
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