[The inhibition of the proliferation and energy metabolism of Cloudman melanoma cells in vitro by aphidicolin and gamma radiation].

PURPOSE

The present investigation is concerned with the effect of aphidicolin (a tetracyclic diterpenoid) and gamma-ray [correction of X-ray] irradiation--alone or in combination--on cell proliferation, protein production, glucose consumption and lactate production of in vitro cultured Cloudman melanoma cells.

METHODS

Monolayer cultures of Cloudman melanoma cells in exponential growth phase were irradiated with 2, 4 or 6 Gy (cobalt-60) or treated for 96 h with 0.1, 0.2 or 1.0 microgram/ml aphidicolin. Further, the combination of 0.1 or 0.2 micrograms/ml aphidicolin with the above mentioned radiation doses were investigated. Measurements were performed in regard to changes of cell number, protein content, glucose consumption and lactate production.

RESULTS

Single treatments resulted in a dose-dependent inhibition of cell proliferation, protein production, glucose consumption and lactate production. Combined treatment with aphidicolin and irradiation caused an augmentation of the respective single effects. The inhibitory effects were more pronounced under serum-free than serum-containing culture conditions. Influence of aphidicolin and irradiation did not result in an immediate cell death, but in a state of unbalanced growth with enlarged cells (in part with an increased number of nuclei) and an increased cellular protein content.

CONCLUSIONS

The combination of aphidicolin with gamma-ray [correction of X-ray] irradiation caused a stronger effect than the respective single treatments.