Cancer under Siege

The growth of a tumor beyond a few millimeters depends on the development of new blood vessels to supply it with nutrients and oxygen. Using magnetic resonance imaging (MRI), Prof. Michal Neeman has developed a number of original non-intrusive techniques to identify the developmental stages of newly forming blood vessels. Her method _ one of the forerunners of its type in the world _ can also keep track of the development of new blood vessels surrounding the tumor. The approach is founded upon the changes occurring in hemoglobin molecules transported in the bloodstream. These molecules serve as a kind of "shuttle," conducting oxygen from the lungs to the various body cells. Neeman, using her method, can distinguish between hemoglobin molecules that carry oxygen and those that have already released their burden of oxygen to the designated body cell. This makes possible the simultaneous observation of a variety of possible states in blood vessels: their density, their oxygen-carrying function, and their ability to control the speed of flow _ a characteristic related to their "maturity." In contrast to healthy tissue, in which all blood vessels are "mature," the tissue of a malignant tumor contains many "young" blood vessels.

On the basis of this distinction, one can selectively destroy a malignant growth without harming healthy tissue. This technique has already been put to use in testing the efficiency of a number of substances that block the development of new blood vessels, and in detecting conditions that promote blood vessel formation and thereby induce tumor growth.

Prof. Michal Neeman's research is supported by the M.D. Moross Institute for Cancer Research; the Willner Family Center for Vascular Biology; Mr. Stephen Meadow, Beverly Hills, California; the Lynn and William Frankel Fund for the Diagnosis and Treatment of Ovarian and Breast Cancer, Philadelphia, Pennsylvania; and Susan and Morris Mark, New York City.