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Archive - May 18, 2011

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Stat5 Marker IDs Breast Cancer Patients Likely to Respond to Tamoxifen

Cancer researchers at the Kimmel Cancer Center at Thomas Jefferson University and an international team of collaborators have discovered a biomarker in breast cancer that may help identify which women will respond to anti-estrogen therapy. The research appeared online on May 16, 2011, in the Journal of Clinical Oncology. Anti-estrogen drugs, most notably tamoxifen, are widely used in patients diagnosed with estrogen receptor-positive breast cancer. However, as many as a third of the women given tamoxifen fail to respond. In this new study, the investigators found that women whose tumors retain the active form of the protein biomarker Stat5 have an increased likelihood of responding to tamoxifen. In contrast, women treated with tamoxifen whose tumors lacked active Stat5 had up to a 20-fold increased risk of dying from breast cancer after adjustment for effects of standard hormone receptor markers and other pathology data. "Identification of predictive biomarkers present in breast cancer will lead to improved individualized therapies tailored specifically towards each woman's cancer," said Dr. Hallgeir Rui, professor of oncology, Kimmel Cancer Center at Thomas Jefferson University, and principal investigator of the study. "Absence of the active form of Stat5 could help identify a group of patients unlikely to respond to tamoxifen so they may be offered alternative and more aggressive treatments." Stat5 protein is a DNA-binding factor that regulates expression of certain genes, many of which remain unknown. During pregnancy, Stat5 is activated by the hormone prolactin, and stimulates milk production in the breast. Active Stat5 is also detectable at lower levels in healthy breast tissue of non-pregnant women.

Imaging Technology Reveals Details of 49-Million-Year-Old Spider

Scientists have used the latest computer-imaging technology to produce stunning three-dimensional pictures of a 49-million-year-old spider trapped inside an opaque piece of fossilized amber resin. University of Manchester researchers, working with colleagues in Germany, created the intricate images using X-ray computed tomography to study the remarkable spider, which can barely be seen under the microscope in the old and darkened amber. Writing in the international journal Naturwissenschaften, the scientists showed that the amber fossil – housed in the Berlin Natural History Museum – is a member of a living genus of the Huntsman spiders (Sparassidae), a group of often large, active, free-living spiders that are hardly ever trapped in amber. As well as documenting the oldest ever Huntsman spider, especially through a short film revealing astounding details, the scientists showed that even specimens in historical pieces of amber, which at first look very bad, can yield vital data when studied by computed tomography. “More than 1,000 species of fossil spider have been described, many of them from amber,” said Dr David Penney, from Manchester’s Faculty of Life Sciences. “The best-known source is Baltic amber which is about 49 million years old, and which has been actively studied for over 150 years. “Indeed, some of the first fossil spiders to be described back in 1854 were from the historically significant collection of Georg Karl Berendt, which is held in the Berlin Natural History museum.