Normally, cells permanently damaged by radiation undergo a genetically programmed process of cell suicide, called apoptosis. Shamsuddin reports that UVB-irradiated human keratinocytes, when treated with IP6, were more likely to survive. Untreated skin cells were more likely to undergo apoptosis, indicating that the DNA in those cells was damaged irreparably and fatally. According to Shamsuddin, the treated cells take an extended pause at the point in the cellular life cycle where innate mechanisms repair DNA before the cell divides.
IP6 certainly has some interactivity with DNA, but how exactly it works to repair DNA is still something of a mystery. There are reports that IP6 binds with DNA repair molecule Ku to bring about the repair process, Shamsuddin said. More importantly, we still dont know how IP6 can appear to help healthy cells live while also enhancing the ability of radiation to kill cancer cells.
Shamsuddin and his team found that when mice engineered to be prone to skin cancer were given drinking water containing a two-percent solution of IP6, they were much less likely to develop tumors. Twenty-three percent of treated mice developed tumors, compared to 51 percent of untreated, or control mice, which developed tumors. Moreover, the mice in the treated group that did develop cancer had only half as many tumors as the control mice.
Similarly, Shamsuddin saw that mice treated with a topical cream containing four percent IP6 plus one percent inositol were also less likely to develop tumors. When they administered the cream an hour before UVB irradiation akin to sun exposure, 62 percent of the treated mice developed tumors compared to 76 percent of the control mice. Accordi
|Contact: Staci Vernick Goldberg|
American Association for Cancer Research