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Changing
Course at the Graduate School
The
appointment of neurobiologist Susan Hockfield as the new dean emphasizes
the growing role of the School of Medicine in the life of the University.
Summer
1998
by Bruce Fellman
Thomas
Appelquist's five-year-term as dean of the Graduate School was
not the easiest of assignments. The
academic job market for recent PhDs has long been poor in many disciplines;
federal support for graduate research, though substantial, is shaky;
and a highly vocal group of teaching
assistants, who felt that their work was undervalued by the
University, engaged in an often rancorous campaign to form a graduate
student union.
While the dean has,
by most accounts, dealt well with these and other challenges, no
one was surprised when Appelquist, the Eugene Higgins Professor
of Physics, announced last year that he would return to teaching
and research rather than seek another term.
Appelquist's successor
is Susan
Hockfield, a professor of neurobiology at the School of Medicine,
who assumed her duties July 1 as the 17th dean in the Graduate School's
151-year history. "This is a wonderful opportunity and a privilege,"
says Hockfield, who was director of graduate studies in neurobiology
from 1986 to 1994 and has written more than 90 scientific papers
and review articles on the biology of the nervous system.
Hockfield is the first
member of the Medical School faculty to head the Graduate School,
and her appointment is seen by at least some observers as an example
of the increasing links between the graduate and professional sectors
of the University. "Neuroscience embraces many disciplines," says
Hockfield, who helped develop the new and collaborative graduate
program in the biological and biomedical sciences. (The new dean,
in addition to managing the Graduate School's 2,300 students and
65 departments and programs, will also be responsible for overseeing
faculty appointments and promotions in the natural and social sciences.)
"I'm very pleased for
Yale," says longtime colleague James D. Watson, the winner, along
with Francis Crick and Maurice Wilkins, of the 1962 Nobel Prize
in Physiology or Medicine for discovering the structure of DNA.
"Susan knows what it takes to keep the University competitive."
Watson, president of
the internationally known Cold Spring Harbor Laboratory (CSHL) on
Long Island, hired Hockfield as a junior staff investigator in 1980
and has worked with her ever since. "Susan quickly became absolutely
indispensable," notes Watson, who, when Hockfield joined the Yale
faculty in 1985, ensured that the researcher would remain part of
CSHL by appointing her director of its prestigious summer program
in neurobiology. (She held that position until last year and remains
a consultant to the laboratory.) "We have all benefited from her
common sense, high character, and intelligence. Simply put, she
gets things done."
Hockfield's
recent work tackles a medical mystery: why a malignant brain
tumor called a glioma is so deadly. "Gliomas are a therapeutic nightmare
because the cells are highly mobile," she explains.
A number of forms of
cancer can spread from a primary site in say, the breast or the
lung, migrate, and take root in the brain. But typically, the resulting
tumors are relatively compact and self-contained and so are amenable
to treatment by such means as surgery or radiation. The cells that
give rise to gliomas, however, originate in the brain, invade the
surrounding brain tissue, and are constantly on the move. There's
very little physicians can do, and frequently, the patient is dead
within a year.
That may change. In
a paper published in April in the Journal
of Neuroscience, Hockfield and her Yale research team present
the first clear explanation of genetic and molecular methods glioma
cells may use to overwhelm the brain. This investigation of basic
cellular biology offers tantalizing strategies for therapy, she
says, and it shows how many scholarly endeavors result from both
directed work and serendipity.
Hockfield, who is 47,
started down this path early. "I've been interested in biology from
the time I was 5 or 6, I was good at math and science, and it never
occurred to me that there was something I couldn't do," she notes.
Her parents encouraged her to pursue her interests, and so did her
teachers.
At the University of
Rochester, Hockfield immersed herself in the study of cell biology
and graduated in 1973, a semester early. "I was advised by an insightful
professor to get a job in a laboratory, and fortuitously, I was
hired as a lab technician in neuroscience. Quickly, I realized that
this was what I'd been looking for all my life," she says.
After a couple of years,
Hockfield enrolled at Georgetown University's School of Medicine,
but not to become a physician, as she'd once planned. Instead, she
pursued a doctorate in anatomy. Hockfield spent most of her time
working in the laboratories of the National Institutes of Health,
where she was part of a team investigating the pathways in the nervous
system through which pain is perceived and processed. Her adviser
there was Steven Gobel, and both he and the setting had a profound
influence on Hockfield's life and her view of graduate education.
"You were immediately treated like a scientist, and Steve was wonderfully
generous with his time and expertise," Hockfield recalls of her
mentor. "He had an awe about the beauty of the nervous system, and
we talked science all the time."
Of course, the Graduate
School that Hockfield now leads trains scholars in the arts and
the sciences, but as she sees it, there are two aspects of the "transformation
by which a student comes in as a student and emerges as a colleague"
that, regardless of one's scholarly discipline, are "absolutely
key" to the process: collegiality, and a passion for research and
teaching.
"I'm enthusiastic about
scholarship of all sorts, whether it's a discovery about the fate
of the universe or a new way to interpret a text," says Hockfield,
adding that although the methodologies may differ, "the stories
we tell -- and that we're training the next generation of scholars
to discover -- are always woven from disparate pieces of data. Figuring
out how to piece these together is the very core of our enterprise."
The
new dean's own research story "certainly didn't come written out
on a petri dish," she admits. In the course of her graduate
training, she developed expertise in electron microscopy with an
eye toward building a taxonomy of the nerve cells, most of which
looked alike, that were involved in pain processing. It was arduous
work, but in the early 1980s, biologists developed what are called
monoclonal antibodies. These molecules can zero in on highly specific
sites on cells, and with the electron microscope, Hockfield could
see precisely where the antibodies were going. "We had a powerful
new tool with which we were discovering molecular differences between
neurons," she says. "What did all this variation mean?"
James Watson wondered
as well, and he hired her to work on the problem at Cold Spring
Harbor, a place she dubbed a "wonderland for science." CSHL, Hockfield
explains, is devoted to research and training in "absolutely cutting
edge science and technology." In her eventual role as director of
the lab's summer neuroscience program, she recruited faculty, secured
research funding, and helped develop courses that provided state-of-the-art
training to close to 200 students each year. In this heady environment,
people ate, drank, and slept research, and here Hockfield found
her "life's work: discovering how the molecular elements of the
nervous system change over the course of development."
Of particular interest
were the changes during development that take place in the chemical
makeup of the extracellular matrix, the space between each nerve
cell. Hockfield continued this line of research when she came to
Yale in 1985, and as she chronicled the brain's strict construction
sequence that begins when a layer of proliferative cells give rise
first to neurons and then to a support structure made up of glial
cells, she observed something intriguing. When the glial cells are
being created, the extracellular matrix is awash in BEHAB -- brain-enriched
hyaluronan binding protein. The only other time BEHAB is abundant
is when a glioma in running rampant.
In a real sense, Hockfield
had been primed for making the transition from basic biology to
tumor research by dinner-time conversation. Her husband, Thomas
Byrne (they have a six-year-old daughter, Elizabeth), is a neuro-oncologist
at Yale-New Haven Hospital and a clinical professor at the Medical
School. "We often talked about gliomas and wondered why they were
invariably fatal," she says.
One key appears to
lie in the tumor's uncanny ability to turn on the nascent gene that
makes BEHAB, the protein that plays a critical role in the glial
cell's ability to proliferate and move during the course of normal
development. "Our experiments indicate that this molecule can mediate
the invasiveness of gliomas," says Hockfield, whose group is now
looking at ways of either turning off the BEHAB gene or preventing
the protein from being activated by enzymes.
In assuming the deanship,
the task of ensuring that current and future generations of graduate
students will continue to have the opportunities she has enjoyed
may mean her own scientific work will slow down. But it won't stop,
says Hockfield, stressing the critical role of research. Says the
new dean: "A vibrant scholarly enterprise is what the University
is all about."
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