Study Links Stress, Hormones in Ovarian Cancer Persistent Tension May Fuel Cancer Progression in Some
Stress has been linked with cancer progression, but for the first time, researchers have demonstrated in a lab how “fight or flight” hormones might make ovarian cancer cells more invasive.
M. D. Anderson researchers have found that norepinephrine and epinephrine, hormones linked to behavioral stress, can enhance the potential of ovarian cancer cells to spread.
“If we knew the biological pathway by which stress is linked to metastasis, then we could investigate how best to avoid those deleterious consequences,” says the study’s lead investigator, Anil Sood, M.D., associate professor in M. D. Anderson’s Department of Gynecologic Oncology. “This study helps shed some light on those mechanisms.”Stress and cancer.
Sood presented the findings at the annual meeting of the American Psychosomatic Society, held March 3-6 in Orlando, Fla. His collaborators include researchers from M. D. Anderson and the University of Iowa.
When a person experiences excessive and persistent stress, the body reacts by releasing many hormones. Research has shown that these “stress” hormones can affect the immune system of cancer patients, and lead to cancer progression in some, but there has been little cell-based evidence for this link, and not much understanding as to why the connection exists at all.
Sood and his collaborators found the first clue when he discovered that ovarian cancer cells show high levels of “beta adrenergic” receptors that allow stress hormones to “dock” onto the cell, promoting a cascade of events inside the cell. Normal epithelial cells from the ovary have very few of the receptors.
Ovarian cell studies
Theorizing the extra receptors must somehow help cancer cells survive and thrive, Sood has conducted a series of studies to test the effect of stress hormones on ovarian cell cultures.
The researchers first demonstrated that stress hormones can directly result in elevated levels of a protein known as vascular endothelial growth factor (VEGF), which is important in cancer progression. Sood and his colleagues had found earlier that women with ovarian cancer who have greater distress and lack of social support tended to have higher levels of VEGF. In work published last fall, they discovered high levels of hormones prompted laboratory cancer cells to produce more VEGF.
Sood says that some other cancer cell types, such as breast and colon, also have been found to have an abundance of stress hormone receptors, although much of that work is in the preliminary stages. “Cancer cells will do whatever works to their advantage. If stress hormones help promote growth and invasion, they will acquire those abilities,” he says.
http://www.cancerwise.org/april_2004/display.cfm?id=b9a90fe6-8cdf-4c69-9e2d8ce4b512959c&method=displayfull&color=red
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