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Archive - Nov 10, 2012

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Ancient Genetic Building Block Discovered in Cyanobacteria

Scientists believe that prior to the advent of DNA as the earth’s primary genetic material, early forms of life used RNA to encode genetic instructions. What sort of genetic molecules did life rely on before RNA? The answer may be AEG, a small molecule that when linked into chains forms a hypothetical backbone for peptide nucleic acids (PNA), which have been hypothesized as the first genetic molecules. Synthetic AEG has been studied by the pharmaceutical industry as a possible gene silencer to stop or slow certain genetic diseases. The only problem with the theory is that up to now, AEG has been unknown in nature. A team of scientists from the USA and Sweden announced that they have discovered AEG within cyanobacteria which are believed to be some of the most primitive organisms on earth. Cyanobacteria sometimes appear as mats or scums on the surface of reservoirs and lakes during hot summer months. Their tolerance for extreme habitats is remarkable, ranging from the hot springs of Yellowstone to the tundra of the Arctic. “Our discovery of AEG in cyanobacteria was unexpected,” explains Dr. Paul Alan Cox, co-author of the paper that appeared November 7, 2012 in the journal PLoS ONE. The American team is based at the Institute for Ethnomedicine in Jackson Hole, Wyoming, and serves as adjunct faculty at Weber State University in Ogden, Utah. “While we were writing our manuscript,” Dr. Cox says, “we learned that our colleagues at the Stockholm University Department of Analytical Chemistry had made a similar discovery, so we asked them to join us on the paper.” To determine how widespread AEG production is among cyanobacteria, the scientists analyzed pristine cyanobacterial cultures from the Pasteur Culture Collection of Paris, France.

Resveratrol Could Be Key to Fighting Prostate Cancer

Resveratrol, a compound found commonly in grape skins and red wine, has been shown to have several beneficial effects on human health, including cardiovascular health and stroke prevention. Now, a University of Missouri (MU) researcher has discovered that the compound can make prostate tumor cells more susceptible to radiation treatment, increasing the chances of a full recovery from all types of prostate cancer, including aggressive tumors. "Other studies have noted that resveratrol made tumor cells more susceptible to chemotherapy, and we wanted to see if it had the same effect for radiation therapy," said Dr. Michael Nicholl, an assistant professor of surgical oncology in the MU School of Medicine. "We found that when exposed to the compound, the tumor cells were more susceptible to radiation treatment, but that the effect was greater than just treating with both compounds separately." Prostate tumor cells contain very low levels of two proteins, perforin and granzyme B, which can function together to kill cells. However, both proteins need to be highly "expressed" to kill tumor cells. In his study, when Dr. Nicholl introduced resveratrol into the prostate tumor cells, the activity of the two proteins increased greatly. Following radiation treatment, Nicholl found that up to 97 percent of the tumor cells died, which is a much higher percentage than treatment with radiation alone. "It is critical that both proteins, perforin and granzyme B, are present in order to kill the tumor cells, and we found that the resveratrol helped to increase their activity in prostate tumor cells," Dr. Nicholl said. "Following the resveratrol-radiation treatment, we realized that we were able to kill many more tumor cells when compared with treating the tumor with radiation alone.