Prevention of genetic breast cancer within reach

Source: Institute of Molecular Biotechnology | Summary: About one in eight women will develop invasive breast cancer over the course of her lifetime. Causes can be the use of synthetic sex hormones and other environmental factors, but also gene mutations like in the BRCA1 gene (BReast CAncer). US actress Angelina Jolie who underwent a preventive double mastectomy is the most famous carrier of a "faulty“ BRCA1 gene.On average, women with this mutation have an up to 87% lifetime risk of developing breast cancer. Tumors usually develop early in life. Until now, prophylactic surgery is the only procedure which significantly reduces the breast cancer risk, but which is also often associated with postoperative complications.

"In 2010, Josef Penninger, the scientific director of IMBA in Vienna and his team have shown that sex hormones can trigger breast cancer (Schramek et al., Nature) through proteins called RANKL and its receptor RANK, which are key factors in bone metabolism. RANKL and RANK also link sex hormones to breast cells by providing signals telling the breast cells to grow. This occurs normally in every woman during pregnancy and the menstruation cycle. However, if deregulated, mammary cells start to divide and multiply and fail to die when they should, ultimately resulting in breast cancer.

A multinational research effort now made the discovery that RANKL is also the main driver of BRCA1 mutation-driven breast cancer. In the current study, Verena Sigl, graduate student from Penninger's research group, showed that blocking the RANKL/RANK system in BRCA1 mutant mice led to largely normal mammary glands whereas invasive carcinomas could be found in the control group. 

To determine the relevance of their results for humans, scientists in Vienna and Toronto isolated breast tissue cells from women who had undergone preventive mastectomy because of their BRCA1 mutation. In the human cell culture, too, RANKL inhibition led to a significant reduction of growth and spreading of breast tissue cells..."

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https://www.sciencedaily.com/releases/2016/05/160531082159.htm

Shared genetics in humans, roundworms shed light on infertility

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Source: Rutgers University | Summary: Humans and worms are connected by a common ancestor that lived more than 700 million years ago and shared a gene that is required for sperm to function properly at fertilization, research confirms. This discovery could lead to more effective infertility treatments and better contraceptives.

"A discovery by Rutgers scientists links a protein in human sperm to the same molecule needed for reproduction in tiny roundworms and may provide clues to human infertility.

In a study published in Current Biology, Andrew Singson, a professor in the Department of Genetics in the School of Arts and Sciences, and colleagues from the National Institutes of Health and the College of William and Mary in Virginia, identified a protein, SPE-45, on the sperm of C. elegan worms that help bind sperm to eggs during fertilization. It is the same as the Izumo protein considered essential for humans and other mammals to reproduce that was discovered a decade ago by Japanese scientists who named it after a marriage shrine in Japan.

"Humans and worms are connected by a common ancestor that lived more than 700 million years ago and this discovery will give us insight into their shared genetics and fertility pathways," said Singson, a principal investigator at the Waksman Institute of Microbiology.

The research suggests that a common ancestor to both worms and humans had a SPE-45/Izumo-like gene that was required for sperm to function properly at fertilization, said Singson, who has been researching the biological process of fertility for the past two decades..."

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A new method furthers understanding of evolutionary genetics

Photo Credit: zmescience.com

"Since Darwin, evolutionary biologists have been fascinated by how different organisms are from one another. The ultimate goal is to understand how mutations in DNA, the genetic blueprint, shape the growth and behavior of animals, plants, and microbes around us. 

Standard research tools have been available for some time to study the genetics of closely related individuals—for example, the variation of lactose intolerance between humans. But understanding differences between long-separated species has remained a challenge. 

Publishing online in Nature, Buck Institute professor Rachel Brem and her colleagues have broken through this roadblock by focusing on distantly-related species of yeast, the single-celled organism used to make beer, wine and bread.

"Yeast is an easy system to work with and a good model for more complicated organisms," said Brem. "It was a great platform for us to develop a method for discovering what makes species unique."

The researchers first noted that some species of yeast were much better than others at deriving energy from galactose, a sugar found in plant materials..."

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