Melatonin Shows Potential to Slow Tumor Growth in Breast Cancers
Hormone reduces tumor volume in cancer models (January 28)
An early-stage study shows that melatonin — a hormone that regulates the body’s sleep and awake cycles — may have the potential to help slow the growth of certain breast cancer tumors, according to researchers at Henry Ford Hospital in Detroit.
The study, published online in PLoS One, finds that melatonin may inhibit tumor growth and cell production, as well as block the formation of new blood vessels, in estrogen receptor (ER)-negative breast cancer models.
Because of melatonin’s suspected antioxidant properties, some believe it may suppress the growth of some types of cancer cells, especially when combined with certain anticancer drugs, according to the American Cancer Society.
A promising tactic in limiting cancer progression is controlling the formation of new blood vessels (angiogenesis). Once a tumor exceeds a few millimeters in diameter, hypoxia triggers a cascade of events to allow angiogenesis and tumor progression.
To determine the therapeutic effectiveness of melatonin on tumor growth, the researchers evaluated the action of melatonin on angiogenesis in ER-negative breast cancer in vitro and in vivo using cell and mouse models, respectively.
Treated mice showed significantly smaller tumors after 21 days, whereas the mean tumor volume increased significantly in the control group. There was also less vascular growth in the tumors of the treated group. These results were replicated in cell models.
According to the authors, the study showed that melatonin administered at a pharmacologic concentration was able to reduce ER-negative breast cancer cell viability in vitro. They caution, however, that this research is still in its early stages, and that the results are not yet ready to be translated for patient use.
Source: EurekaAlert; January 28, 2014.