Cytotoxic Effect of Dexamethasone Restricted to Noncycling, Early G1 Phase of Melanoma Cells

Abstract

This study deals with the inhibitory effects of dexamethsone on the proliferation of a human melanoma cells after separation into different fractions according to their position in the cell cycle using a gravity sedimentation chamber. Fractions with high percentage of G1 cells were more susceptible to the action of dexamethsone than those with a lower percentage of G1 cells. Dexamethsone stimulated the rate of incorporation of radioactive precursors into acid-precipitable materials of melanoma M-5A cells starting 24 hours after treatment for one hour. Moreover, dexamethsone treatment markedly increased the volume of the M-5A cells with increasing the possibility of stimulating the transcriptional/translational activity in the cells. This study may hopefully stimulate the development of new approaches in systemic and/or regional chemotherapy with malignant melanoma using dexamethsone with other alkylating agents to get synergestic interaction