Study of the radiosensitivity of three melanomas grown in vitro

This work studies the response to gamma irradiation of three human melanoma stems. Two cellular lines come from two ganglion metastases, the third from a primitive tumor. The influence of ''out-of-cycle''(quiescent cells on the radiosenitivity of a tumoral population was investigated in parallel with ''in cycle'' cells. The materials and methods used are described, and a number of cynetic parameters of the populations are given. The results of a series of experiments carried out on the IGR11 stem are presented; this enables the evaluation of the repair capability of potentially lethal lesions of cells remaining in the plateau phase, after irradiation, without removal of the nutritional medium. The survival curves of the 3 stems, in both the exponential growth and the ''plateau phase'', are presented. A heterotransplant model of a human melanoma to ''nude'' mice is considered. (B.G.)