Decreasing Deuterium Concentration of Water: A Possible Tool in Colon Cancer Therphy

Purpose: Recent studies show that the depletion of naturally occurring deuterium can result in tumor regression in both in vitro and in vivo models. In the present paper we report the inhibitory effect of different concentrations of DDW discretely and in combination with 5-FU on HT29 colon cancer cells and the possible mechanisms underlying these effects. Methods HT29 cells were treated with decreasing deuterium concentrations of DDW individually, 5-FU alone and both from 24 to 72 h. Cellular cytotoxicity of the cells were determined by the MTT proliferation assay. The morphology and structure of the cells were observed by scanning electron microscopy (SEM). Results We observed the changes in the cell cycle by flow cytometry and alterations in the cellular antioxidant enzymes by transmission chemiluminescence. Treatment with DDW especially in concentrations of 50 and 75ppm alone imposed inhibitory effects on the growth of the cell line and DDW augmented 5-FU inhibitory effects on HT29 cell lines. The cell cycle analysis revealed that DDW caused the cell cycle arrest in the G1/S transition, reduced the number of the cells in the S phase and significantly increased the population of cells in the G1 phase in HT29 cells. We observed that DDW induced the cellular antioxidant defense system. Under SEM examination, the control cells showed smooth surface and more extracellular matrix, while the DDW exposed group showed a rough surface and more microvillus on the cell surface. Conclusions We conclude that DDW is a promising new adjuvant anti-cancer agent with the potential for future clinical applications.