

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).
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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).
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