Research is shedding new light on sunscreens that might someday prevent or treat skin cancer by reversing dangerous gene mutations caused by overexposure to the sun.
Working with hairless mice, researchers found that a synthetic compound called CP-31398 helped stabilize damage in the tumour-suppressing p53 gene. This type of damage occurs in humans and mice alike after sustained exposure to the sun’s ultraviolet B (UVB) rays.
Once treated and repaired, the UVB-exposed p53 mouse gene resumed its normal cancer-preventing activity, inhibiting the spread and proliferation of tumour cells.
“Once the skin is exposed to UVB it leads to mutations in the p53 gene, and it becomes non-functional, and then you see induction of skin cancer” explained study lead author Mohammad Athar, a professor of dermatology at the University of Alabama, Birmingham.
“But this compound we used interacts with the p53 mutant genes and converts them back into functional genes,” he said. “And that led to less incidence of skin cancer tumours, fewer numbers of tumours, and slower tumour growth in the UVB-exposed mice populations we tested.”
In all, the authors conducted four mouse experiments during which the animals were irradiated with UVB for periods of time ranging from 16 weeks to 40 weeks.
Some mice were given topical or injected versions of CP-31398, either immediately before a scheduled exposure to UVB, immediately following it, or for an extended period of weeks following discontinuation of all UVB exposure. For comparison purposes, other mice were not given CP-31398 at all.
CP-31398 seemed to prevent the onset of cancer altogether in UVB-exposed mice treated prior to the development of tumours, the team found. The compound also appeared to limit the growth of skin tumours that had formed prior to the treatment’s application. In both cases, the observed success was attributed to the compound’s ability to jumpstart proper p53 function, the researchers said. Athar pointed out that p53 mutations linked to skin cancer are also present in more than half of all tumour types, so the current work could theoretically lead to cancer prevention applications for a range of diseases beyond melanoma.
Dr Robin Ashinoff, the medical director of dermatologic, mohs and laser surgery at Hackensack University Medical Centre in Hackensack, New Jersey, said, “If we can work at the genetic level to try and prevent skin cancer where it starts and correct and suppress the abnormal clones that arise from UVB exposure, that would certainly be quite advantageous. And it would be wonderful to be able to put this approach into a creme or a sunblock. That-when it happens-will certainly become the new gold standard.”
Sources: The Times Of India