Breast cancer may be more likely to spread to the bones with night exposure to subdued light

Researchers have shown for the first time in an animal study that exposure to low light in the evening, common in today's lifestyle, could contribute to the spread of bad cancer up to ## 147 ## # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # To the bones. The results of the study will be presented Saturday at the annual meeting of the Endocrine Society, ENDO 2019, in New Orleans, Louisiana.

"To date, no one has reported that nocturnal exposure to low light induces circadian disturbances, which in turn increases the formation of metastatic bad cancer of the bones," said Muralidharan Anbalagan, Ph.D., professor Assistant to the Tulane University School of Medicine in New Orleans, La. This is important because many patients with bad cancer are likely exposed to light at night due to lack of sleep, stress, excessive light in the bedroom from appliances mobile and other sources, or night work. "

According to an estimate from the National Cancer Institute, more than 150,000 American women have had bad cancer in 2017, which has metastasized or spread outside of the bad. When bad cancer spreads, it often reaches the bones, where it can cause severe pain and fragile bones.

In this preliminary study funded by the Louisiana Center for Translational and Clinical Sciences (LACATS) in collaboration with the Louisiana Cancer Research Consortium (LCRC) and the Tulane Center for Circadian Biology, researchers created a model murine bone metastatic bad cancer. They injected human bad cancer cells with positive estrogen receptors that have a low propensity to develop in the tibia, or tibia, bones of female mice. Like humans, the mice used in this study produce a strong nocturnal signal of circadian melatonin. This nocturnal signal of melatonin has been shown to produce strong anticancer actions and also promote sleep.

All the mice were kept in the light for 12 hours a day. A group of three mice were in the dark the other 12 hours, which helped them to produce high levels of endogenous melatonin. Another group spent 12 hours in the light, followed by 12 hours in the dark at night, which inhibits their nocturnal production of melatonin. According to Anbalagan, the dimmed light was 0.2 lux, which is less than a night light or a cell phone light.

X-rays showed that mice exposed to a light / low light cycle had much larger tumors and larger bone lesions than mice maintained in a standard light / dark cycle, he said.

"Our research has highlighted the importance of an anticancer signal of intact nocturnal circadian melatonin in suppressing the growth of metastatic-bone metastatic tumors," Anbalagan said.

The ultimate goal of their research, he said, is to find a way to inhibit or suppress the progression of bone metastases from bad cancer.

Provided by
The endocrine society