Each month brings new investigative tools, as well as commercial and therapeutic applications of existing technologies. No one can predict which of today’s discoveries will most shape tomorrow’s industries, but these synopses describe recent research that warrants attention.

Viral Healing

Gene therapy keeps mice with Lou Gehrig–like disease healthier, alive longer.

Context: No effective therapy exists for Lou Gehrig’s disease, also known as amyotrophic lateral sclerosis (ALS), a deadly illness that kills muscle-controlling neurons and atrophies the muscles responsible for breathing and voluntary movement. Nor is there any reliable way to predict who will get it. However, mice genetically engineered to produce too much of a mutant version of the protein superoxide dismutase-1 (SOD1) develop symptoms of ALS within 90 days. Although scientists have identified compounds that can delay the disease in mice before symptoms develop, the recent publication by researchers at the Salk Institute for Biology and Johns Hopkins University is the first report of a method to postpone paralysis and death after symptoms appear.

Synopses

Viral Healing

Akt 1: Affairs of the Heart

Better Prediction with Proteins

Surgery Sees the Light of Day

Get the Lead Out

Immunity from Self-Attacks

A Big Fat Greek Diet

Kaspar, B.K. et al. (2003) Retrograde viral delivery of igf-1 prolongs survival in a mouse als model. Science 301:839–42.

Akt 1: Affairs of the Heart

Genetically modified stem cells repair damage after a heart attack.

Context: The body heals itself after a heart attack, but incompletely. Attempts to augment this healing by injecting mesenchymal stem cells (MSCs) into the heart have been disappointing. This is probably not due to MSCs’ inability to repair heart tissue, but to the fact that fewer than 1 in 100 MSCs survive long after injection. To improve the survival rate, Mangi et al. at the Brigham and Women’s Hospital and Harvard Medical School introduced a gene, Akt1, into rat MSCs and found that these modified cells are potent healers after simulated heart attacks in rats.

Mangi, A.A. (2003) Mesenchymal stem cells modified with Akt prevent remodeling and restore performance of infarcted hearts. Nature Medicine, published online before print.

Better Prediction with Proteins

Molecular signatures identify patients likely to die within a year of diagnosis.

Context: Lung cancer is the leading cause of cancer death in the developed world. Though individual patients’ cancers vary greatly in how they spread to other tissues and respond to drugs, patient treatment varies little. Currently, experts stain cells with diagnostic dyes and examine them under a microscope to determine whether a tissue sample has cancerous cells, and to classify the cancer. Such examination alone usually cannot predict whether cancer has spread to other tissues and how long a patient will live. Data about gene expression may lead to better prediction, but these data lack information about protein levels and modification. A more accurate view of a cell’s activity requires the more difficult task of probing the protein content directly, a task that Yanigisawa et al. at Vanderbilt University achieved with remarkable success for nonsmall-cell lung cancer (NSCLC).

Yanigisawa, K. et al. (2003) Proteomic patterns of tumour subsets in nonsmall-cell lung cancer. Lancet 362:433–9.

Surgery Sees the Light of Day

Concentrated sunshine offers cheap alternative to lasers.

Context: In wealthy countries, laser fiber-optic surgery is used frequently to burn away tumors in tissues, including the breast, cervix, esophagus, liver, and prostate. However, this technique is too expensive for many health care centers. In animal surgeries, Gordon et al. at Ben-Gurion University of the Negev in Israel show that surgeons can use sunlight to the same effect, for as little as a 100th of the cost.

Gordon, J.M. et al. (2003) Surgery by sunlight on live animals. Nature 424:510.

Get the Lead Out

Plants may be able to clean contaminated soil.

Context: Four of the six top pollutants at U.S. Superfund sites are heavy metals: arsenic, cadmium, lead, and mercury. Plants may be able to pull these toxins out of the soil, but to be useful in cleanup efforts, toxins must move from the roots of plants to the stems and leaves. Plants detoxify metals using molecules called phytochelatins to bind metal ions. These phytochelatins sequester metals in parts of individual cells that function essentially as toxic waste dumps. In the past, scientists assumed most toxins absorbed by plants simply remained underground in the roots, and so plants would not be a viable way to clean contaminated soil. As part of a project to understand precisely how plants absorb heavy metals, Gong et al. at the University of California at San Diego found, to their surprise, that plants capable of producing phytochelatins only in their roots transported much of the heavy metal to the stems and leaves.

Gong, J.M., D.A. Lee, and J.I. Schroeder (2003) Long-distance root-to-shoot transport of phytochelatins and cadmium in Arabidopsis. Proceedings of the National Academy of Sciences, U.S.A. 100:10118-23.

Immunity from Self-Attacks

Protein microarrays identify self-antigens, direct DNA vaccine.

Context: Cures for autoimmune diseases such as multiple sclerosis and rheumatoid arthritis must stop the body’s immune system from attacking its own tissues. One hope for abating these attacks is a tolerizing vaccine. In this poorly understood process, organisms are injected with DNA encoding antigens that are recognized inappropriately. (An antigen is any molecular fragment the immune system singles out for attack.) This treatment somehow weakens the immune system’s response to it. The approach has been stymied by overwhelming numbers of inappropriate antigens and by difficulties in identifying them. Recently, Robinson et al. at Stanford University reported a potential way to overcome both of these problems, as well as to predict the severity of autoimmune diseases.

Robinson, W.H. (2003) Protein microarrays guide tolerizing DNA vaccine treatment of autoimmune encephalomyelitis. Nature Biotechnology, published online before print.

A Big Fat Greek Diet

Bringing new meaning to Meds.

Context: Myths about healthy eating abound. While several small studies have indicated that the classic Mediterranean diet contributes to health, these results could be due to chance or artifact and have focused on elderly, rather than general, populations. To get a more definitive answer, Trichopoulou et al. at the University of Athens Medical School used a survey of more than 22,000 Greek citizens to correlate diet with health.

Trichopoulou, A.T. et al. (2003) Adherence to a Mediterranean diet and survival in a Greek population. New England Journal of Medicine 348:2599–608.