Gene-Based Sunscreen Might Someday Prevent Skin Cancer

Gene-Based Sunscreen Might Someday Prevent Skin Cancer
FRIDAY, Dec. 7 (HealthDay News) -- Research is shedding new lighton sunscreens that might someday prevent or treat skin cancer by reversingdangerous gene mutations caused by overexposure to the sun.
Working with hairless mice, researchers found that a synthetic compoundcalled CP-31398 helped stabilize damage in the tumor-suppressing p53 gene.This type of damage occurs in humans and mice alike after sustainedexposure to the sun's ultraviolet B (UVB) rays.
Once treated and repaired, the UVB-exposed p53 mouse gene resumed itsnormal cancer-preventing activity, inhibiting the spread and proliferationof tumor cells.
"Once the skin is exposed to UVB it leads to mutations in the p53 gene,and it becomes nonfunctional, and then you see induction of skin cancer "explained study lead author Mohammad Athar, a professor of dermatology atthe University of Alabama, Birmingham.
"But this compound we used interacts with the p53 mutant genes andconverts them back into functional genes," he said. "And that led to lessincidence of skin cancer tumors, fewer numbers of tumors, and slower tumorgrowth in the UVB-exposed mice populations we tested."
Athar's findings are published in the December issue of The Journalof Clinical Investigation.
In all, the authors conducted four mouse experiments during which theanimals were irradiated with UVB for periods of time ranging from 16 weeksto 40 weeks.
Some mice were given topical or injected versions of CP-31398, eitherimmediately before a scheduled exposure to UVB, immediately following it,or for an extended period of weeks following discontinuation of all UVBexposure. For comparison purposes, other mice were not given CP-31398 atall.
CP-31398 seemed to prevent the onset of cancer altogether inUVB-exposed mice treated prior to the development of tumors, the teamfound.
As well, the compound appeared to limit the growth of skin tumors thathad formed prior to the treatment's application.
In both cases, the observed success was attributed to the compound'sability to jumpstart proper p53 function, the researchers said.
Athar pointed out that p53 mutations linked to skin cancer are alsopresent in more than half of all tumor types, so the current work couldtheoretically lead to cancer prevention applications for a range ofdiseases beyond melanoma.
"We tested UVB-signature mutations, but every cancer-causing agent thatinteracts with p53 has its own form of mutation," he noted. "So, we needto see if different types of cancers can be attenuated with this type ofcompound."
"We are also planning to conduct more studies in mice to see if thecompound we used has any toxicity, although we did not find that to be thecase so far," he said. "So, we are planning long-term studies with mice.Once that is complete, we will certainly go for clinical trials withhumans."
In the interim, Dr. Robin Ashinoff , the medical director ofdermatologic, mohs and laser surgery at Hackensack University MedicalCenter in Hackensack, N.J., said that the current findings should beviewed with a mix of interest and caution.
"This still needs to be studied in human trials in a placebo-controlledfashion," she noted. "And bringing this kind of technology to market isalways a long road."
"But if we can work at the genetic level to try and prevent skin cancerwhere it starts and correct and suppress the abnormal clones that arisefrom UVB exposure, that would certainly be quite advantageous," she added."And it would be wonderful to be able to put this approach into a creme ora sunblock. That -- when it happens -- will certainly become the new goldstandard."