[Radiation-induced differential responses of uterine adeno- and squamous cell carcinoma spheroids in dose-survival relationships].

Radiation-induced dose-survival relationships of human uterine adeno and squamous carcinoma cells grown as spheroid were studied, comparing them with monolayer cells. HEC-59 and SKG-3a cell lines were used. The spheroids were produced by Yuhas's method. In monolayer culture, D0,Dq and n values in the Hit-theory were as follows: HEC-59 (D0 = 1.6Gy, Dq = 0.6Gy, n = 1.5) and SKG-3a(D0 = 1.3Gy, Dq = 0.4Gy, n = 1.4). Survival curves of both cell lines as spheroids demonstrated biphasic curves after acute irradiation. HEC-59 cells grown as spheroids 300 microns in diameter did not have a great second component. SKG-3a cell, however, did apparently have a large amount of the second component when a 6Gy dose was exceeded. The shoulder in the dose-survival curves of both cells grown as spheroids became greater than monolayer cells up to 3Gy dose. It was therefore proven that spheroids possess similar characteristics to solid tumors. This suggests that spheroids are useful in studying radiation-induced effects in solid tumors.