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Treatment
The main
source for this web page appeared in the July 5th, 2002 issue of Science Magazine
under the title Sustained Loss of a Neoplastic Phenotype by Brief Inactivation
of MYC. The research was conducted
at Stanford University and the University of California, San Francisco. The importance of the paper is the effect of
a treatment that inactivated a specific oncogene, MYC, in transgenic mice. The first part of the paper is structured to
show that the doxycycline (Dox) treatment the group was using caused tumor
regression in the mice. This figure
shows the effects of the Dox treatment; 
The pictures on the left side are
stained to show tumor cells present in different tissues, and the pictures down
the right side show the same cell types after the mice had been treated with
Dox. These results are not
groundbreaking; Dox had been shown in previous papers to have this effect on
mouse tumor cells. However, this is the
point where the paper becomes really interesting, because most previous Dox
treatment papers had continuously administered the treatment, and not studied
what happened to the tumor cells when the Dox treatment was stopped. It would be logical to assume that the tumor
cells would start to grow once the treatment was stopped. The group of researchers decided to continue
observation of the cell types after a 10-day Dox treatment cycle. These graphs show the tumor cell growth and
death patterns during and after the Dox treatment:
Both of these figures show the
same thing; that the tumor cells did not start to grow again after the Dox
treatment was stopped. The graph shows
that the cells did not start to grow back after the Dox treatment was
stopped. The stained slides on the right
side (D,H,L) give visual confirmation that the tumor cells weren’t growing 14
days after the treatment was stopped.
The group also added a section to the paper showing increased survival
of the 10-day Dox cycle mice over tumor expressing mice that had not been
treated. The importance of this study is
immense, because it shows that a treatment can be used in mice to effectively
inactivate oncogene expression and halt tumor growth; and once the treatment is
stopped the tumor cells do not grow back.
The possible uses for a treatment like that are very promising for cancer
research in the years to come.
Note: All
figures on this page were taken directly from the PDF version of the article
Sustained Loss of a
Neoplastic Phenotype by Brief Inactivation of MYC
Meenakshi Jain,Constadina
Arvanitis, Kenneth Chu, William Dewey, Edith Leonhardt, Maxine Trinh, Christopher
D. Sundberg, J. Michael Bishop, Dean W. Felsher
Science 2002 297: 63-64
Home Mitosis Meiosis
P53 Apoptosis Cancer History of Cancer
Treatments Transgenic Mice
Dox Treatment Future of Dox Credits