Hershey, Pa. --- Researchers from Penn State's College of Medicine have shown that specific tumor cells can be engineered in mice so that they can suppress growth to a secondary site.
"As with most cancers, it is the spread of the cancer, rather than the primary malignancy that is the principal cause of death. We showed that these cells go through all steps in the metastatic process, except growth, at the secondary site," says Danny R. Welch, Ph.D., associate professor of pathology. "On a practical basis, because we are inhibiting cell growth at the site of metastasis, in this case the lungs, we may be able to treat cells that have already spread by blocking their ability to grow into a tumor which impairs function."
Welch and his colleagues, Steven F. Goldberg and John F. Harms, presented this work recently in a paper titled, "Metastasis-suppressed C8161 Melanoma Cells Arrest in Lung but Fail to Proliferate," at the 91st annual meeting of the American Association for Cancer Research meeting in San Francisco. Welch and his team placed two sets of human malignant melanoma cells into mice. Those cancer cells with a restored chromosome 6 did not metastasize. Those cells with a defective chromosome 6 spread from the skin and developed tumors in the lung.
"We watched the cells closely over hours, days, weeks and months. The cells completed every step except growth," stated Welch. "We know there is communication taking place between tumor cells and cells in the organs to which they spread. There is also some kind of interaction taking place, but the nature of that interaction is not well defined. These findings represent an opening whereby we can understand the communication taking place so that one day therapies can regulate it."
The Penn State researcher further explains that this work has implications beyond melanoma. The molecules involved here may be early insight as to why certain cancers spread preferentially to some organs. For example, breast cancer spreads to lymph nodes and then two-thirds of patients get bone metastasis. Colon cancer spreads first to the liver. Consequently, he believes that cancer cells can only survive in certain places and that is where they migrate.
"There is a great potential here to develop very targeted therapies for cancer that metastasize to different organs," says Welch, This research is funded by the National Institutes of Health, the National Foundation for Cancer Research, and the Jake Gittlen Cancer Research Institute at The Milton S. Hershey Medical Center.