The University of Arizona

Blazing New Trails

By Nick Prevenas, The University of Arizona Cancer Center | July 20, 2012

G. Timothy Bowden, an emeritus professor who recently was diagnosed with Parkinson's disease, is looking into a potential link between Parkinson’s and an increased risk of melanoma.

Tim and Diane Bowden
Tim and Diane Bowden

When G. Timothy Bowden wasn’t hard at work on his many research projects within The University of Arizona Cancer Center’s cellular and molecular medicine program, he could often be found hiking up Mount Lemmon or through the Sabino Canyon trails with his wife, Diane, at his side.

Things changed in 2007, however, as Bowden was diagnosed with Parkinson’s disease. It’s a condition that can have devastating effects on a patient’s balance and motor skills – a dangerous combination for anyone attempting to navigate rocky terrain.

But through serious attention to detail and a rigorous exercise routine, the Bowdens now are hiking more than ever, thanks in large part to Parkinson’s Wellness and Recovery Gym, or PWR! Gym, a Parkinson’s-specific exercise program. Becky Farley, a physical therapist and exercise physiologist at the UA, started the PWR! program in 2010 to emphasize specific exercises that help reduce symptoms for Parkinson’s patients.

“We’ve found that certain intense exercises help ease the motor disturbances and rigidity that accompany Parkinson’s disease,” said Bowden, a professor emeritus of cellular and molecular medicine who retired from the UA two years ago.

In 2011, the Bowdens’ 15-mile hike through Mount Lemmon covered 5,000 feet in elevation and raised more than $10,000 for the gym. They repeated the feat once again this year.

This is Bowden’s typical response to adversity. Instead of dwelling on the potential pitfalls of a situation, he uses the circumstances to investigate possible solutions.

In that spirit, Bowden is part of a research team looking into a potential link between Parkinson’s disease and an increased risk of melanoma.

Bowden indicates that published studies have shown that Parkinson’s patients are between two and 20 times more likely to be diagnosed with malignant melanoma – and vice versa.

“It wasn’t until very recently that this correlation became apparent,” Bowden said. “It’s imperative that we help get this message out there, both for Parkinson’s patients and for those with melanoma.”

Bowden's research is in the field of molecular and cellular biology, pharmacology/toxicology and radiation oncology. He has been a UACC member since 1978, served as the center’s chief scientific officer and continues to have an active research laboratory at the UACC. He has a long-standing interest in skin cancers, and he began studying links between the two diseases shortly after his diagnosis.

He began working with Dr. Scott Sherman, a professor of neurology at the UA, as well as Bowden’s primary neurologist, on this study more than a year ago. Fellow neurology researcher Torsten Falk and Brian S. McKay, a research associate professor of ophthalmology and vision science, joined the research effort soon after.

This group of researchers is working on the theory that variations in the oculocutaneous albinism II gene (OCA2) act as the link between Parkinson’s and malignant melanoma. The OCA2 gene product helps control the synthesis of melanin, which is present in melanocytes in the skin and in neurons in the brain – neurons that often die in Parkinson’s patients.

Alterations in pigmentation controlled by the OCA2 gene could lead to the death of L-DOPA-producing neurons and malignant transformation of melanocytes in the skin, giving rise to potential malignant melanoma formations.

The group has spent the past year gathering preliminary data and is in the process of applying for grants from the National Institutes of Health and the Michael J. Fox Foundation to continue its research.

“We want Parkinson’s patients to start getting melanoma screenings as soon as possible,” Bowden said. “It never used to be a part of the standard Parkinson’s exam. Now, Parkinson’s patients need to schedule regular screenings – at least twice a year.”