[Retention of tumorigenicity in radioresistant progeny of cells surviving exposure to high doses of gamma irradiation].
The cell tumorigenic ability and the cell clonogenicity in semi-solid medium of highly radioresistant variant cell line, PIC-20 (the progeny of djungarian hamster fibroblast cell line DX-TK- surviving acute exposure to 20 Gy of gamma-irradiation), were examined. In the absence of additional radiation, no differences between tested features of non-irradiated PIC-20 cells and parental DX-TK- cells were observed. On the contrary, after gamma-irradiation with high doses the essential differences in the properties of the examined cell lines were revealed. After exposure to 10 Gy the surviving fraction of PIC-20 cells was 20 times higher than that of the parental cells. Both irradiated and non-irradiated PIC-20 cells produced colonies of similar size. It is revealed that even after irradiation with doses of 5, 10 or 15 Gy, the PIC-20 cells kept their tumorigenicity as high as non-irradiated ones. In all these cases the 90-100% of animals had the tumour, with the average latent period of tumour appearance after inoculation being the same both for irradiated and non-irradiated PIC-20 cells. After irradiation of parental DX-TK- cells with the highest dose of 15 Gy, the amount animals with tumour decreased by 70% and the average latent period of tumour appearance increased fivefold as compared with that for non-irradiated DX-TK- cells. The data obtained indicate that PIC-20 is highly radioresistant cells, which are able to proliferate both in semi-solid medium and in an animal organism even after radiation exposure to high doses.
Slanina
S V
SV
Moscow Scientific and Industrial Association Radon, Moscow, 119121 Russia. database@newmail.ru
Kakpakova
E S
ES
Mitin
V N
VN
Kalendo
G S
GS
Tyrsina
E G
EG
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D002472:Cell Transformation, Viral / Q000528:radiation effects*; D002999:Clone Cells; D006224:Cricetinae; D003470:Culture Media; D005347:Fibroblasts / Q000528:radiation effects*; D005720:Gamma Rays; D011829:Radiation Dosage; D011836:Radiation Tolerance
D003470:Culture Media