ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The relationship between alkaline phosphatase activity and cell growth has been studied in hamster cells transformed by different carcinogens. About 90% of normal hamster embryo cells were constitutively positive for alkaline phosphatase activity (AP+). However, there were no AP+ cells in cell lines transformed after treatment with the chemical carcinogens dimethylnitrosamine or 4-nitro-quinoline-N-oxide and 0.02% and 4% AP+ cells in cell lines transformed by polyoma virus or Simian virus 40. The glucocorticoid hormone, prednisolone, induced alkaline phosphatase activity in 12% and 44% of the enzyme-negative (AP-) cells in cell lines transformed by polyoma or Simian virus 40, but this hormone did not induce alkaline phosphatase activity in AP- cells from cell lines transformed after treatment with the chemical carcinogens. Treatment of polyoma transformed AP- cells with the mutagen N-methyl-N′-nitro-N-nitro-soguanidine produced AP+ cells, whereas no AP+ cells were found after mutagen treatment of AP- cells from the chemically transformed cell lines. Studies on spontaneous segregation in the polyoma transformed cell line has shown that AP+ cells segregated AP- cells both in vitro and in vivo, although no spontaneous segregation was observed from AP- to AP+ cells.AP+ cells, compared to AP- cells, showed a decrease in DNA synthesis, cell multiplication, the ability to form colonies in soft agar and tumorogenicity in animals. AP- cells induced for alkaline phosphatase activity by prednisolone, showed the same growth properties in vitro as uninduced AP- cells. The decreased cell growth found in AP+ cells which were constitutive for alkaline phosphatase activity was therefore not found in the hormone induced AP- cells. The results indicate that constitutive alkaline phosphatase activity appears to be related to the regulation of cell growth and that AP- cells have a selective advantage over AP+ cells.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040830105
