Adenosine 3',5'-cyclic monophosphate dependent and independent protein kinase activities in 1,2-dimethylhydrazine induced rat colon cancer.
The adenosine 3',5'-cyclic monophosphate (cAMP)-dependent and cAMP-independent kinase activities were measured in the 1,2-dimethylhydrazine (DMH) induced rat colon cancer and in untreated colon. Previous studies had shown that intestinal tumors induced by chronic exposure to DMH contained 2-fold less intracellular cAMP. The present findings indicate that reduction in cAMP-dependent protein kinase activities also occur in colon cancer cells. Similar hydrogen ion dependence (pH 6-7) and approximate association constants (Ka approximately 0.1 microM) were observed for the enzymes existing in both normal and tumor tissues, while the cAMP-dependent tumor protein kinase was found to phosphorylate phosvitin and casein to a greater degree. These recent findings are consistent with the concept that the concentrations of cAMP and activities of its associated enzyme system are inversely related to the cell proliferation state.
D019813:1,2-Dimethylhydrazine; D000818:Animals; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000201:enzymology*; D000242:Cyclic AMP / Q000378:metabolism*; D004127:Dimethylhydrazines; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D013997:Time Factors
D004127:Dimethylhydrazines; D009363:Neoplasm Proteins; D000242:Cyclic AMP; D011494:Protein Kinases; D019813:1,2-Dimethylhydrazine