Shigehiro Odo and colleagues at Kyushu University in Fukuoka, describes how the antitumor drug interferon-a affects the body clock and how this may lead to serious side effects in an article in today's issue of Nature Medicine.
Known side effects from the cancer-treatment drug include depression, neurosis and even suicidal tendencies.
The essential biological function is regulated by light, which determines when "clock genes" are turned on and off. This in turn affects hormone output and body temperature.
The effectiveness and toxicity of many drugs change radically according to the time they are administered because of the body clock.
Odo and his team investigated the effects of interferon-a on mice and found that repeated administration of the drug disrupted clock genes and altered the way the body clock is cued by light.
"Optimizing the dosing schedule can minimize adverse drug effects," the researchers said. The work could lead to improved cancer treatments with reduced toxic side effects.