[Role of Mg2+-dependent alkaline endodnaase of blood serum in tumorigenesis in A/smail mice].
An enzymoassay of levels of Mg2+-dependent alkaline endoDNAase of protein spectrum of blood serum of noninbred albino mice by SDS-electrophoresis in 10% PAAG established a fairly high heterogeneity of the enzyme. The variety of alkaline endoDNAases must be due to the limited proteolysis of their high-molecular precursor by specific proteases as described in the literature. No alkaline endoDNAase activity was identified by analysis of 10-150 kDa protein spectrum in A/smail line mice without ascites hepatoma. It was detected (pH 8.3) in the 25-45 kDa range on day 10 after tumor transplantation. Considering the gravity of disease (pre-lethal stage), on day 10, it was suggested that the level be accounted for by decay of diseased cells. The lack or extremely low level of endoDNAase activity in original blood serum expressed a mechanism of enhancing sensitivity to tumor cell effects. In mice bearing ascites hepatoma, the enzyme levels (pH 8.3) were much higher on day 10. DNAase activity (pH 7.5) was not induced in response to the heterogenous DNA. Our data point to possible defects in the induction of Mg2+-dependent alkaline endoDNAases (pH 8.3) and DNAses (pH 7.5) as well as their role in raising sensitivity to transplantable ascites hepatoma.
Kovalenko
G A
GA
Lel'kin
M K
MK
Panin
L E
LE
D000818:Animals; D003851:Deoxyribonucleases / Q000097:blood*; D004591:Electrophoresis, Polyacrylamide Gel; D008274:Magnesium / Q000378:metabolism*; D051379:Mice; D009374:Neoplasms, Experimental / Q000473:pathology*
D003851:Deoxyribonucleases; D008274:Magnesium