Biological cells may react to their environments somewhat akin to the
way children are influenced by their neighborhoods and schools, an
increasing number of scientists believe. Cell biologist Mina Bissell
believes a key element in the formation of cancer is not just what
happens within a cell, but the interactions of cells and all the tissue
surrounding them. With certain environmental changes, cancer cells that
might have remained harmless can flourish.
Distinguished Scientist at the Lawrence Berkeley National Laboratory,
has been researching the behavior of cancerous cells and gene mutations
for three decades."Old Ideas Spur New Approaches in Cancer Fight",
a December 29 New York Times
story by Gina Kolata, describes how the work of Dr. Bissell and others
is beginning to change the way scientists think about cancer.
Scholars, pharmaceutical companies, and even former scientific skeptics
are beginning to realize that the micro-environment of cancerous cells
can't be ignored."Thinking Outside the Cell,"
a story by Kara Platoni, quotes Dr. Nancy Boudreau
one of Dr. Bissell's post-doctoral fellows who now directs the surgical
research laboratory at the University of California at San Francisco,
on Dr. Bissell's innovative scientific approach: Dr. Bissell was
investigating overall function at a time when most other researchers
were looking at individual components. Dr. Boudreau recalls an
experiment in Dr. Bissell's lab in which mammary cells essentially
committed suicide after tissue around them was destroyed. As Dr.
Boudreau explains it, cells fit into a communication network provided by
the matrix, or surrounding material, and when both are communicating
correctly, the potential for malignancy is kept in check. When signaling
between cell and matrix is disrupted by age, inflammation or other
adversities in the micro-environment, the cell loses its social context.
In the resulting disorder, she says, "the tumor cell is like a nutjob
on the street that says "I don't care'."Zena Werb,
vice chair of the anatomy department at UCSF,a friend and frequent
collaborator with Dr. Bissell, observes children and cells absorb
environmental influences: A smart youngster raised in an environment
where crime pays may excel at criminality, and the same youngster raised
in an environment that rewards scholarship might become a concert
pianist. So will a rogue cell behave normally if its environment is
In a 1997 paper in the Journal of Cell Biology
Dr. Bissell reported that breast tumor cells dosed with a certain
antibody reverted to a normal state. In a 1999 paper she reported that
previously normal mouse mammary cells underwent malignant or
premalignant gene changes when their micro-environment was degraded,
disrupting communication between the cells and their matrix.
Others who have pursued similar ideasare also receiving belated recognition. The Times
story notes Dr. D. W. Smithers wrote in a 1962 article in The Lancet
that cancer is a disorder of cellular organization, and not one of malignant cells that run amok and kill the host. The Times
story also says in 1975, another cancer scientist, Beatrice Mintz,
of the Fox Chase Cancer Center in Philadelphia, inserted mouse cancer
cells into mouse embryos. The embryos developed normally, even though
the remained present as the mouse grew. But injection with the same
cells would kill an adult mouse. Dr. Bissell was fascinated by the work.
She and one of her students found that a virus that caused fatal tumors
when injected into adult chickens did not cause cancer in chickens
whose embryos had been injected with the cells.
work also provides clues on why some cancers develop after wounds and
injuries, and why the US breast cancer rate in women over age 50 dropped
15 percent in 2003 and the next year. Hormone therapy for menopausal
women declined after a 2002 federal study that the treatment actually
produced a slight risk for heart disease and breast cancer, the story
says, and scientists now suspect the therapy may have changed the
structure and activity of breast tissuein ways associated with higher