'TROJAN HORSE' TECHNIQUE DESTROYS TUMORS
Texas researchers have demonstrated a new drug that targets and destroys blood vessels supplying malignant tumors in mice without harming blood vessels in the surrounding normal tissue. "This is like a 'Trojan horse' approach to kill the blood vessels that supply solid tumors," the researchers said. The new drug uses a substance that promotes blood vessel growth -- which is critical for the tumor's survival -- to zero in and poison the tumor. For the study, mice were injected with human melanoma and human prostate cancer cells. The mice receiving the new drug, called VEGF/rGel, had tumor growth only 16 percent as extensive as the untreated mice. "The anti-tumor effects of the (drug) against both melanoma and human prostate cancer in mouse models was impressive in magnitude and prolonged," the researchers said. "These studies suggest that VEGF/rGel has potential as an anti-tumor agent for treating cancer patients."
BACTERIA CAN COMBAT ZEBRA MUSSELS
A common soil bacterium produces a toxin that kills Zebra mussels. The pesky creatures were first identified in June 1988 in Lake St. Clair, the body of water near Detroit lying between great lakes Huron and Erie. Scientists theorize Zebra Mussels most likely arrived in the ballast water of ships from Europe. To date, they have caused an estimated $1 billion in damages, blocking intake pipes for electric power and water treatment plants, irrigation systems, and other industrial and recreational facilities. In small trials, researchers used the bacterium, called Pseudomonas fluorenscens, to eliminate up to 95 percent of the mussels attached to the pipes at a hydropower facility. The bacterium destroys a digestive gland within the mussel, leading to its death. It also does not seem to harm untargeted species, including fish and native mussels. Because even dead Pseudomonas cells kill zebra mussels, researchers suspect it contains a toxin within its cell walls, so they are working to identify and purify the substance.
BIO-ENGINEERING COULD HELP CANCER DRUGS
A group of anti-cancer agents that once proved ineffective in clinical trials could still help to fight the deadly disease, a team of researchers from the University of Washington and in Germany reports. The agents, called maytansinoids, were first discovered in the 1970s when scientists looked for tumor inhibitors in a rare Ethiopian plant. Maytansinoids also were later isolated from a new bacteria species. The compounds held great promise because of their exceptional potency. Early tests showed they were effective against some tumors and leukemias. But the compounds were difficult to come by in commercial quantities and they proved potentially toxic when tested in clinical trials. Now the researchers are planning to modify the genes that create maytansinoids. If they are successful, the substances could resume their role as leading candidates for cancer treatments that are effective against tumors, but they also would be well-tolerated by patients.
ESCAPING MASS EXTINCTION DOES NOT GUARANTEE SURVIVAL
It turns out many organisms that survived the biggest mass extinctions in Earth's history later died off for other reasons, a new study by a University of Chicago scientist has found. David Jablonski researched the aftermath of mass extinctions at the end of the Mesozoic Era. He determined how many species survived each of the extinctions only to die off within five or 10 million years. He found 17 percent of complex organisms went extinct after three of the five big extinctions. A surprising result, said Jablonski, who had assumed that surviving a mass extinction would be good news for most major groups. "It wasn't good news for everybody," he said. "It's clear that there is a lot of evolutionary action in the aftermath of mass extinctions. During the rebound ... it's not an all-or-nothing thing. The shape of the post-extinction world comes not only from who goes extinct, but from which survivors are successful -- or, instead, become extinct or marginalized in the aftermath."
(Editors: For more information on TUMORS, contact Wayne Carter at 214-648-3404 or [email protected]. For ZEBRA MUSSELS, Ben Sherman at 202-662-7095 or [email protected]. For BIO-ENGINEERING, Vince Stricherz at 206-543-2580 or [email protected]. For EXTINCTIONS, Cheryl Dybas at 703-292-8070 or [email protected])
