[Characteristics of a stable long-term cell line obtained from a dedifferentiated human astrocytoma]. / Kharakteristika mnogoletnei stabil'noi kletochnoi linii, poluchennoi iz dedifferentsirovannoi astrotsitomy cheloveka

There has been obtained and is being maintained in vitro for over 12 years a stable cellular line DAPT, derived from a dedifferentiated human astrocytoma. In monolayer cultures the cells have passed 270 times. During 22 month (63 passages) the cells had a fibroblast-like shape, their growth having thereafter assumed an epithelioid character. On being impregnated with chlorous gold after Ramon-and-Kachal the cellular cytoplasma is stained purple-violet. In the periods of the fibroblast-like and epithelioid growth the time of the population doubling was 145 and 74 hours, respectively. The mitotic index amounted to 18%. When investigated during the 3d (106th passage) and 11th (250th passage) years of its cultivation the population consisted largely of cells containing 60-65 chromosomes. The carotype of the DAPT cells retained the main traits common to the structure of the human caryotype. After 7-9 months of cultivation (16-25th passages) the DAPT cells demonstrated the presence therein of an active glutamineketoacidic aminotransferase. Further on the activity of the enzyme declined. Factors influencing the changeability of the stable cellular DAPT line are discussed.