Evening star., 1950-03-13
New Drug Holds Hope
OF Retarding Cancer;
Effective CITY in Animals
By Thomas R. Henry
Science Editor Of The Stor.


cells has been announced by the
American Cancer Society. While
there is no promise that the find.
ing ever will prove of value Ii
treatment of human cases, it il
regarded as one of the most sig.
niflcant advances yet made ir
cancer research.
One possibility held out is thai
malignant growths may eventual.
ly be kept under control by life.
long injections, much as diabetes
is controlled by insulin.
One of the substances essentia
to the growth and multiplication
OF nearly every living animal eel
is one of the amino acids, guanine
1t is a white, crystalline substance
used in the synthesis Of artificia.
pearls.
Microscopic Animal Involved.
Despite it's vital role, it is not
essential in diet. Nearly every
animal manufactures the materia
out of another amino acid in its
own body But there is one strik-
ing exception: a microscopic ami
NAL, similar to the amoeba, named
tetrahymena, cannot synthesize
guanine. The essential substance
must be supplied by its diet.
Some years ago, DR.. George w
Kidder and his associates at Am
herst College started experiment.
ing with this popularity of the
tetrahymena with no idea that
it might have any bearing on the
cancer problem. They found that
the microscopic animals, consist
ing essentially of single cells
could be "kidded" into starving
themselves.
This was accomplished by feed
ing them a substance chemically
very similar to guanine, called
"guanazole." The cell, it de-
veloped, could not distinguish be-
tween the two substances. 1t
seemed, in fact. to prefer guiana
zole, although this material was
completely useless to it. AS a re-
suit, the organisms system OF
multiplying quickly broke down
Cancer Cell Is Similar.
Now a cancer cell is roughly
similar to a tetrahymena. Its
system of growth and multiplied
ton is generally the same. DR.
Kidder and his associates played
a daring hunch. Presumably the
cancer cell, like every other ami
NAL cell, requires guanine. This
it synthesizes itself. The Amherst
experimenters decided to test
whether the cancer cell also could
be "kidded." If guanazole were
injected into the body, would the
cancer cell, unable to distinguish
the difference. accept it rather
than go to the labor of synthesiz-
ing guanine?
They tried it on mice with q
particularly malignant and rapid.
growing type of glandular cancer
In one mouse after another, daily
injections stopped cancer growth
They started growing again as
soon as the injections 4 were
stopped. The cells themselves were
not killed. They had lost, how
ever, the essential ability to null
tiply, without which cancer would
be essentially harmless. ~ 81.
Then the researchers made tests
with two other forms of mouse
cancer. The results were identi-
cal.
Injections were tried on healthy
mice. No poisonous effects what
soever could be found.
, Results Have Been Confirmed.
DR.. Kidder's results now have
been confirmed by other laborato-
ries, according to the Cancer So
ciety's announcement, There has
been some disagreement, however
on effects on various types of can
Ger.
The drug still is a long way
from clinical use, it is stressed.
So far as is known, no tests have
been made on human beings. A
long series of clinical trials, con-
flrmed over long periods by many
physicians, will be necessary be-
fore the effects Of the treatment
can be confirmed or disproved
1t Is by no means certain that
human cancer cells will act in
the same way as those in mice.
1.-THE odds against success" says
the society's report, "' ." are
enormous.
However results turn out, it Is
stressed, guanazole never can be
considered a cancer cure" but
only something to hold growth
in check.