Enhanced antitumor activity of vitamin C via p53 in Cancer cells

Chemoprotective effect of ascorbic acid on cyclophosphomide induced oral toxicity

“…Ascorbate cytotoxicity seems to be more effective in cells with higher levels of p53, and because the natural body cells have lower levels of p53 than tumor cells, ascorbate does not damage these cells as much. 23 The CTX/ Water treated group of the present study showed a significant decrease in epithelial thickness, a significant increase in damage scores, and a significant decrease in PCNA immune expression. Zhao et al (2009) 24 found the same changes in the tongue of mice, but following radiation.…”

“…It can thwart the growth of tumors, halt a tumor cell in the middle of its metabolic cycle, and cause tumor cells to die. 23 P53 has been shown to increase cellular oxidative stress, which helps to destroy cancer cells or at least to inhibit their growth. Ascorbate cytotoxicity seems to be more effective in cells with higher levels of p53, and because the natural body cells have lower levels of p53 than tumor cells, ascorbate does not damage these cells as much.…”

The Hypoxia-inducible Factor Renders Cancer Cells More Sensitive to Vitamin C-induced Toxicity

“…2E). This supports the idea that, besides HIF, other mechanisms regulate the sensitivity to Vc in cancer cells, in agreement with findings by others (26,27). Therefore, the synergistic effect of HIF in promoting the toxicity of Vc is not restricted to renal cancer cell lines and happens in cancer cell lines of different origins.…”

“…It was shown later that a possible reason for the discrepancy is that intravenous Vc produces much higher plasma concentrations than those achieved by oral consumption (21,22). More recently, Chen et al (23,24) demonstrated that megadose Vc has potent cytotoxic effects on a variety of cancer cell lines in vitro and when they were grown as xenografts, findings that have been reproduced by others (25)(26)(27). Chen et al (23,24) also showed that megadose Vc has little or no effect on normal cells in vitro.…”

“…SVCT2 is highly expressed in some breast cancers, suggesting that this type of cancer is more susceptible to megadose Vc than others. Interestingly, another group described that p53 inactivation diminishes the sensitivity of different cancer cell lines to Vc (26). The latter is important because P53 is the most frequently mutated tumor suppressor gene in human cancers (31).…”