SCANNING ELECTRON-MICROSCOPY AND TRANSMISSION ELECTRON-MICROSCOPY ASPECTS OF SYNERGISTIC ANTITUMOR-ACTIVITY OF VITAMIN-C VITAMIN K-3 COMBINATIONS AGAINST HUMAN PROSTATIC-CARCINOMA CELLS

A MTT/formazan assay was used to evaluate the antitumor activity of vi tamin C (Vit C), vitamin K-3 (Vit K-3), Or vitamin C:vitamin K-3 combi nations against a human prostatic carcinoma cell line (DU145). Both Vi t C and Vit K-3 alone exhibited antitumor activity, but only at elevat ed doses. When Vit C and Vit K-3 were combined at a C:K-3 ratio of 100 :1 and administered to the carcinoma cells, the 50% cytotoxic concentr ations (CD50) Of the vitamins decreased 10- to 60-fold. Subsequently, the DU145 cells were examined with transmission and scanning electron microscopy (TEM and SEM) following a 1 hour treatment with Vit C, Vit K-3, or Vit C/K-3 combined at their 50% cytotoxic dose. Our morphologi cal data suggest that vitamin treatment with individual vitamins affec ts the cytoskeleton, the mitochondria, and other membranous components of the cell. Treatment with the vitamin combination appears to potent iate the effects of the individual vitamin treatment. Specifically, th ere are abundant necrotic cells. The surviving cells display morpholog ical defects characteristic of cell injury.