Researchers here at Hopkins’ IBBS are studying many aspects of cancer, including assessing the risk of getting cancer, preventing it, understanding how it develops and treating it.
Cancer is a class of disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis.
Some cancers arise from spontaneous mutations in a cell’s genetic material, while other cancers can be passed from one generation to the next. Mutations can be caused by exposure to radiation, such as UV rays from sunlight, or chemicals or physical agents called carcinogens.
The transformation of a normal cell into a cancerous often requires several mutations. Generally, cells contain specific enzymes that are quite efficient at finding and correcting mutations. However, some mutations do escape detection.
The amount and types of enzymes found in cells vary from person to person. The activities of certain enzymes also can contribute to the number of mutations acquired and to the development of or protection against cancer.
Paul Talalay and colleagues in Pharmacology and Molecular Sciences have developed animal and cell culture systems for studying how these special enzymes are controlled. They have identified and isolated from vegetables minor dietary components that block cancer development. Talalay’s research team continues to identify chemicals in vegetables using molecular biology, biochemistry and cell biology in effort to develop strategies for reducing cancer risk in people.
One of the deadliest aspects of cancer is metastasis, where cancer cells travel through the blood, lymph or other tissues and spread to the rest of the body. Denise Montell and colleagues in Biological Chemistry are studying how cells switch from being stationary to migratory. Using the fruit fly, Montell’s research team has identified dozens of genes and proteins that regulate this process. Using time-lapse video microscopy, they continue to study how a cell’s neighbors or other environmental cues can influence whether the cell stays put or moves.
Cancer can affect people at all ages, but risk tends to increase with age. Each time a cell divides its chromosome ends—called telomeres--become shorter. Cells generally stop dividing before telomeres become too short because short telomeres lead to damaged chromosomes. An enzyme called telomerase lengthens telomeres and therefore allows cells to divide indefinitely. More than 90 percent of human cancer cells have telomerase activity.
Carol Greider and colleagues in Molecular Biology and Genetics have shown that inhibiting telomerase can stop the growth of cancer cells. Using mice engineered to lack telomerase, Greider’s research team has shown that under some circumstances tumor formation is reduced in the absence of telomerase. They continue to study telomerase and its control. Curbing telomerase may be one approach to curbing cancer progression.
Forming new blood vessels—a process known as angiogenesis—is necessary for tumor growth and metastasis, so blocking angiogenesis potentially could be a good strategy for treating cancer. Jun Liu and colleagues in Pharmacology and Molecular Sciences are identifying small molecules that target and stop angiogenesis. Liu’s team has identified the protein critical for growth of blood vessel cells. By studying what this protein does as well as chemicals that prevent the protein from functioning, Liu and his research team hope to identify new candidate drugs to use in treating cancer.