Preclampsia, a serious high blood pressure syndrome that only occurs during pregnancy, may paradoxically reduce the incidence of developing breast cancer in women who develop it, a University of Minnesota Medical School researcher has found.
Globally, preeclampsia and other hypertensive disorders of pregnancy are a leading cause of maternal and infant illness and death. By conservative estimates, these disorders are responsible for 76,000 maternal and 500,000 infant deaths each year, affecting at least five percent of all pregnancies, according to the Preeclampsia Foundation.
Preeclampsia typically occurs after 20 weeks gestation when the blood supply in the placenta of the developing baby becomes restricted. It is a rapidly progressive condition characterized by high blood pressure and the presence of protein in the urine. Swelling, sudden weight gain, headaches and changes in vision are important symptoms; however, some women with rapidly advancing disease report few symptoms. The disorder can force babies to be born premature to protect the life of the mother and child.
Anne Gingery of the Department of Physiology and Pharmacology at the University of Minnesota Medical School in Duluth has investigated how specific factors released from the placenta of women with preeclampsia inhibit the growth of breast cancer cells. She is presenting her findings at the 2010 Experimental Biology meeting in Anaheim, CA, April 24-28, 2010.
Dr. Gingery's research restricts the blood flow of rats' placentas with clips to induce preeclampsia. In rats and humans, the placenta has many blood vessels, so the factors released during preeclampsia end up in the blood stream. The serum – what is left after the cells are filtered out of the blood – of these animals possesses anti-cancer properties.
Gingery tested an array of breast cancer cells treated with the serum that resulted in decreased growth of cancer cells.
Her research focuses on two factors released during preeclampsia: sFlt-1, a soluble version of a protein called VEGF (vascular endothelial growth factor), that regulates the growth of beta cells, and soluble endoglin, a co-receptor for transforming growth factor (TGF) beta cells .
Gingery proposes that soluble endoglin inhibits cell growth by reducing the signaling of the TGF pathway, an important factor in breast cancer development and progression. According to Gingery, at the early stages of cancer this pathway often suppresses tumor growth, but in advanced cancer it can actually promote cancer progression.
Although expectant mothers who develop preeclampsia may be protected from future breast cancer, the benefit does not extend to her child but researchers aren’t sure exactly why. Researchers also don't know yet if preeclampsia could offer other health benefits.
If Gingery's findings for rat pups holds true for humans, children whose mothers experienced preeclampsia during pregnancy are more likely to develop breast tumors than non-preeclampsia babies.
The researchers are currently examining the time it takes to develop tumors and the characteristics of the tumors in rat populations. On-going research is evaluating over time if the mothers with the preeclampsia will indeed have a reduced incidence of breast tumors.
Gingery speculates that perhaps the factors released during preeclampsia affect the stem cells of the mammary gland in some way that changes how the cells develop, which could produce anti-cancer benefits. However she is quick to point out that the research is in its early stages and much is still unknown.
By studying the affects of preeclampsia on the protection against breast cancer, Gingery hopes to identify new targets that can be used in prevention and the development of therapeutics.
“Preeclampsia is not a condition we want any mother to endure,” explains Gingery. “We are simply using a unique way to find factors to be used for care and treatment of cancer. Sometimes it just takes looking at a question differently.”
Lynette Summerill is an award-winning journalist who lives in Scottsdale, Arizona. In addition to writing about cancer-related issues, she writes a blog, Nonsmoking Nation, which follows global tobacco news and events.