Radiation sensitivity of cultured human glioblastoma cells.

Glial cells from 2 normal brains and 9 astrocytomas were cultured in vitro. The most rapidly proliferating cell lines were obtained from Grades III-IV astrocytomas. Normal glia proliferated slowly and growth ceased after 20 to 40 generations. The response of 3 Grade III-IV lines to graded doses of radiation was determined by colony formation and end point dilution technique. Two of the 3 lines were relatively radioresistant compared to other human cell lines; this may partially account for the radiation resistance of high grade astrocytoma tumors.