title: Survival curves after X-ray and heat treatments for melanoma cells derived directly from surgical specimens of tumours in man.
abstract: X-ray and heat survival curves were established for melanoma cells derived directly from surgical specimens of tumours in man by using the Courtenay soft agar colony assay. The plating efficiency for 11 of the 14 melanomas studied was sufficiently high (PE = 0.3-58%) to measure cell survival over at least two decades. Experiments repeated with cells stored in liquid nitrogen showed that the survival assay gave highly reproducible results. The melanomas exhibited individual and characteristic survival curves whether exposed to radiation or heat (43.5 degrees C). The Do-values were in the ranges 0.63-1.66 Gy (X-rays) and 33-58 min (heat). The survival curves were similar to those reported previously for human melanoma xenografts. The radiation sensitivity of the cells was not correlated to the heat sensitivity. Since the melanomas appeared to be very heterogeneous in radiation response in vitro as melanomas are known to be clinically, it is suggested that melanomas may be suitable for prospective studies aimed at establishing whether clinical radioresponsiveness somehow is related to in vitro survival curve parameters.
mesh_terms: D000328:Adult; D000368:Aged; D002470:Cell Survival; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D012878:Skin Neoplasms / Q000473:pathology*; D013997:Time Factors; D014410:Tumor Stem Cell Assay; D014965:X-Rays