34 New Tests Help Chemotherapy Hit the Mark
Not all chemotherapy drugs are equally effective for all people, and finding the best treatment for an individual is a painful process of trial and error that wastes time and exposes patients to toxic side effects. In October Anil Potti of Duke University reported that new tests can dramatically improve the odds of choosing the right drugs for a particular patient's cancer.
Potti and his colleagues began by testing chemotherapy drugs on cultured cell lines from human tumors, such as from the lung, breast, or ovary. Then they linked the drug sensitivity of the tumor cells to the profile of genes expressed in those cells. When the team compared their results to previously published clinical and genomic data, they found that their model successfully predicted patients' chemotherapy response more than 80 percent of the time.
Clinical trials for targeted therapies, selected on the basis of the genomic tests, are scheduled to begin in early 2007. "This gives a message of hope to both patients and physicians that chemotherapy does not have to be random, and does not have to be associated with avoidable toxicity. It's a win-win situation," Potti says.
Jennifer Barone
38 Lab Cooks Up a Healthier Pig
Bacon and sausages that are good for you? Possibly. In April scientists announced they had engineered transgenic pigs that produce omega-3 fatty acids, the same compounds that make fish such a healthy meal.
Most animals lack the gene to convert omega-6 fatty acids—which, when eaten in large amounts, contribute to heart disease, cancer, diabetes, and arthritis in humans—into healthier omega-3s. The only way to enrich meat with omega-3s has been to feed animals flaxseed, fish oil, or fish meal.
Scientists from Harvard University, the University of Pittsburgh, and the University of Missouri at Columbia devised another solution: inserting into pig cells a gene that codes for an enzyme that converts omega-6s to omega-3s. The modified cell nuclei were then inserted into unfertilized eggs to create engineered pig embryos, which were implanted in a normal sow. The result: eight omega-3-generating pigs, whose ratio of omega-6s to omega-3s was fivefold lower than in ordinary piglets.
Whether this pig goes to market remains to be seen. The FDA has yet to permit any genetically modified animal to enter the human food chain.
Nicholas Bakalar
Two transgenic piglets (right) are as healthy as their normal littermate.
