Neoplastic transformation and characterization of human fibroblasts by treatment with 60Co gamma rays and the human c-Ha-ras oncogene.
Human fibroblasts (KMST-6) immortalized by treatment with 60Co gamma rays were further neoplastically transformed by transfection of the c-Ha-ras oncogene from human lung cancer. The ras-transfected cells formed undifferentiated fibrosarcoma in nude mice. One of the tumors was recultured and a neoplastic human fibroblast line, KMST-6/RAS, was established. To analyze multistep carcinogenesis of human cells, the cellular characteristics of these genetically matched immortalized (KMST-6) and neoplastic (KMST-6/RAS) cell lines were studied in detail. KMST-6/RAS cells showed an increased saturation density, colony formation on confluent monolayers of normal human fibroblasts, proliferation in neomycin-containing medium, anchorage-independent growth, and enhanced expression of the transfected c-Ha-ras oncogene, whereas the immortalized cells did not demonstrate these characteristics. Unexpectedly, growth of KMST-6/RAS cells was serum-dependent, although they were neoplastic. Interestingly, the neoplastic cells did not show the criss-crossing or piling up growth pattern characteristic of transformed rodent fibroblasts.
Jahan
I
I
Department of Cell Biology, Okayama University Medical School, Japan.
Mihara
K
K
Bai
L
L
Namba
M
M
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000528:radiation effects; D003037:Cobalt Radioisotopes; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects; D005720:Gamma Rays; D011905:Genes, ras; D006801:Humans; D051379:Mice; D008819:Mice, Nude
D003037:Cobalt Radioisotopes