Targeting PTEN May Prevent Skin Cancer

Scientists believe they have identified a role for PTEN, a known tumor suppressor, in removing DNA damage derived from UVB radiation, a known risk factor for non-melanoma skin cancer, according to a study published in Cancer Research, a journal of the American Association for Cancer Research.

Yu-Ying He, Ph.D., an assistant professor of medicine at the University of Chicago, found that laboratory mice with reduced levels of PTEN were more likely to have UVB-induced skin cancers.

“This was an unexpected finding and definitely provides a new approach for chemoprevention strategies,” she said. “It’s possible that if we can increase PTEN activity through nutritional supplements or some sort of pharmaceutical intervention, we may be able to prevent this common cancer.”

Non-melanoma skin cancer is the most common cancer in the United States. The 1 million cases diagnosed last year accounted for 40 percent of all new diagnosed cancers. Scientists know that the major risk factor for this type of skin cancer is UVB radiation from sunlight, which leads to DNA damage.

PTEN, which was first identified in 1997, promotes genomic stability and cellular repair and can lead to a reduction in the molecular misfiring that leads to cancer and tumor progression.

In the current study, He and colleagues exposed skin cells to UVB radiation and examined the rates of DNA repair. Those with lower PTEN levels had slower rates of DNA repair, because of loss of the key DNA repair protein xeroderma pigmentosum C (XPC). Importantly, if the scientists restored the levels of XPC, then the rates of DNA repair went up as well.

“Cells without appropriate levels of PTEN were not able to repair sufficiently,” said He.

He called the idea of a chemoprevention trial “promising,” and said that her lab plans to assess the chemopreventive potential of restoring PTEN function.

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The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, the AACR is the world’s oldest and largest professional organization dedicated to advancing cancer research. The membership includes 33,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowships and career development awards. The AACR Annual Meeting attracts more than 18,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. Including Cancer Discovery, the AACR publishes seven major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. AACR journals represented 20 percent of the market share of total citations in 2009. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists.