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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Show Me the Tumor
9 July 1997 7:00 pm
Like a mark of death, engineered proteins called monoclonal antibodies are supposed to stick to cancer cells and flag down immune fighters to destroy a tumor. But such a strategy, for some unknown reason, has generally failed. Now, scientists may have found a way to turn monoclonal antibodies into killing machines after all: by linking them together. The findings, reported in the current issue of the Proceedings of the National Academy of Sciences, suggest that antibody dimers could be a promising new approach to developing cancer treatments.
Those rare monoclonal antibodies that are able to kill cultured tumor cells appear to do so through an unexpected mechanism: Instead of attracting other immune cells, the antibodies trigger the tumor cell to stop dividing or to undergo apoptosis, or programmed cell death. A team led by Ellen Vitetta of the University of Texas Southwestern Medical Center in Dallas set out to examine this phenomenon in cells from Burkitt's lymphoma, a disease in which a kind of white blood cell called B lymphocytes divides uncontrollably, resulting in tumors throughout the body. Monoclonal antibodies designed to latch onto several different receptors on the lymphoma cells were almost powerless. In large quantities, however, an antibody to one receptor, CD19, showed a faint capacity for inhibiting cell growth. Some of these antibodies, the researchers found, had formed pairs; when separated out and tested alone, these dimers packed a powerful punch.
The researchers next tested dimers of monoclonal antibodies to other lymphoma receptors. All were better at arresting tumor cell growth or promoting cell death. The researchers also tried the anti-CD19 antibody in mice with human Burkitt's lymphoma tumors. Mice given the dimers, they found, lived up to 80% longer than mice given the monomers. "It's an interesting observation," says immunologist Martin Glennie of the University of Southampton, U.K., "but the mechanism remains obscure." Vitetta's team will try to figure that out in further tests in mice.