Fall 2004 Table of Contents
News from the College
Teeth Hold Clues to Cancer Development,
Says NYU Dental Professor



A 16-day-old mouse embryo in which two genes that code for proteins controlling cell division, p27 and p107, have been inactivated. The embryo was stained to separately reveal cartilage (blue) and mineralized bone (red). Researchers use these images of ‘gene knockout’ mice to learn about normal and abnormal development. Dr. Bromage’s analysis will be useful for future research on issues ranging from the evolution of skeletal structure to therapies for skeletal disorders, cancer, and other diseases (p27 gene dysfunction has been implicated in a variety of cancers, including colon, prostate, breast, lung, pituitary, esophagus, and bladder).

Dr. Timothy G. Bromage, a paleoanthropologist whose discovery of a 2.4-million-year-old jaw in equatorial Africa 12 years ago unearthed the oldest known remains of the human genus, believes that insights about tooth and bone biology gleaned from his expeditions in Africa’s savannahs can be valuable to cancer researchers.

“We know from studying the evolution of young humans and animals, that teeth and bones grow incrementally, a bit every day. But environmental stressors, such as carcinogens in air or water, can alter that growth. Those alterations may provide clues to questions about how to prevent and treat cancers linked to environmental factors,” says Dr. Bromage, who recently joined NYUCD as an Adjunct Professor of biomaterials and biomimetics and of basic science and craniofacial biology.

One of Dr. Bromage’s projects will be to study tooth and bone development in animals living in areas with polluted air and groundwater, such as in sections of Long Island, for clues that could help identify which carcinogens contribute to high human cancer rates reported in those areas. By analyzing certain animals, such as mice and frogs, that can easily be observed in a laboratory, Dr. Bromage hopes to gain insights that could form the hypotheses for more complex research on human cancer victims from those polluted areas. At the same time, the analyses of modern-day carcinogens’ effects on animal development will contribute to a broader understanding of the impact that environmental changes have had on the evolution of entire ecosystems from early through modern times.

Dr. Bromage, who holds a PhD in biological anthropology from the University of Toronto, has already received a $400,000 grant from three private Spanish foundations to establish this project as a formal partnership between cancer and human evolution researchers in the United States and Spain. His plan calls for NYUCD to partner with New York’s Memorial Sloan-Kettering Cancer Center to facilitate results-sharing from this and other cancer-related studies. The two institutions are already collaborating on an $8.3 million, NIH-funded NYU College of Dentistry grant entitled “Research for Adolescent and Adult Health Promotion (RAAHP) Center.”

Dr. Bromage also hopes to share his insights on tooth and bone development with NYUCD colleagues working on stronger, more efficient biomaterials for dental implants and other applications, such as artificial bone used to correct facial deformities.

An array of hardware and software has arrived at the College of Dentistry along with Dr. Bromage, including computer programs for three-dimensional reconstruction similar to the one he used 13 years ago to reverse anthropologist Richard Leakey’s claim that he had discovered the skeletal remains of an ancestral species of the genus Homo with features related to those of modern man. Dr. Bromage’s simulated reconstruction of the skull, based on fundamental principles of craniofacial development and architecture, showed more ape-like characteristics, illuminating a flaw in Dr. Leakey’s reconstruction, which was performed by hand, according to Dr. Leakey’s preconceptions that earliest Homo should have looked more like today’s humans.

Dr. Bromage also brings with him the world’s only portable confocal microscope, which he built himself, for analyzing microscopic details below the surface of teeth and bones (conventional microscopes can only illuminate such details after they have been ground into very thin sections). His laboratory will have New York City’s only two microscopes capable of providing three-dimensional imaging in real time (other microscopes rely on software to reconstruct images in three dimensions).