National Expert in Melatonin's Link to Fighting Cancer Joins Tulane University

December 11, 2008

Keith Brannon
Phone: 504-862-8789

Dr. David Blask, a widely acclaimed expert on cancer biology, circadian rhythms and the health implications of exposure to light at night has joined Tulane University School of Medicine as a professor of practice in the Department of Structural and Cellular Biology.

In the early 1980s, Blask was one of only a handful of scientists studying regulation of breast cancer development and growth by melatonin, a hormone produced by the pineal gland (a small pine cone-shaped gland located near to the center of the brain) during sleep in the darkness of night.  Melatonin modulates many of the body’s natural circadian rhythms, or the daily cycle of biological activity during a 24-hour period, including the sleep/wake cycle.  Melatonin has been shown to have important anti-cancer properties. 

“This was considered fringe science at the time and several colleagues warned that pursuing this area of study would be a career breaker,” Blask says.

However, his lab at the University of Arizona was the first to demonstrate that nighttime blood levels of melatonin directly suppress human breast cancer cell growth.  Dr. Steven Hill, current Structural and Cellular Biology chair, was a graduate student in Blask’s lab at the time and performed these groundbreaking experiments. 

“It was one of those ‘Eureka’ moments that don’t come too often in one’s career,” Blask said. Since then, he has become a world-renowned expert on the negative health implications and increased cancer risk associated with melatonin suppression due to exposure to light at night.

Using specially designed photoperiodic chambers, which allow precise control over light exposure at night, he and his research team were the first to demonstrate that manipulating light intensity at night, and thus melatonin production, dramatically affects human breast cancers growing in rats. Their experiments showed that reduced levels of melatonin caused by brighter intensities of light at night boosted human breast cancer tumor growth in rats. 

This landmark research helped to lay the groundwork for a scientific working group (of which Blask was a member) appointed by the World Health Organization to add shift work and exposure to light at night to its list of possible carcinogens.  Shift workers have been shown to have higher risks for breast, prostate and other cancers. 

Blask was also recently invited to brief a group of Congressional staffers on the implications of light pollution on the environment in June as part of an effort to get the Environmental Protection Agency to address the problem.

“Dr. Blask’s arrival will help us to further develop our efforts to build a center of excellence in circadian melatonin cancer biology,” said Hill, who hopes to add additional scientists to his team in the near future.  “There is only one other group in the United States working in this area.  As we continue to recruit the best and brightest in this field, Tulane is in a position to become the world’s premiere center for research into cancer chronotherapy and prevention.”

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