National Cancer Institute - NCI Division of Cancer Treatment and ...

DTP oversees animal-production facilities that produce
inbred and hybrid strains of rats, mice, and guinea pigs.
This program provides researchers nationwide with
genetically defined, pathogen-free laboratory animals.
Animal Production
http://dtp.nci.nih.gov/branches/btb/
services.html#AnimalProduction
DTP’s Biological Testing Branch oversees
animal-production facilities that produce
inbred and hybrid strains of rats, mice,
and guinea pigs. This program provides
researchers nationwide with genetically
defined, pathogen-free laboratory animals
as well as animal-related services such
as jugular vein cannulations, vasectomies,
ovariectomies, and castrations. In 2005,
the branch distributed 1,473,062 rodents
to about 1700 investigators at 240
institutions.
In Vitro Screening: The Human
Tumor Cell Line Assay
http://dtp.nci.nih.gov/branches/btb/
ivclsp.html
In 1985, the hypothesis was put forward
that a human tumor cell line screen
could help investigators discover celltype–specific
agents with clinical activity
against solid tumors. The emerging reality
was that while correlation of in vitro histology
to clinical activity is poor, the pattern
of cellular sensitivity and resistance of
the cell lines to the drug correlated with
molecular target expression.
In response, DTP developed a cell-line–
based screen representing the major
classes of solid tumors. That allowed
relatively inexpensive and rapid testing
of potential therapeutic agents against
broad panels of human tumors that
could be adapted to the needs of natural
product screening.
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Since April 1990, DTP has used the human
tumor cell line in vitro screen as its primary
assay with follow-up in vivo evaluation in
the hollow fiber assay. The screen is currently
composed of 59 human tumor cell
lines, representing leukemia, melanoma,
and cancers of the lung, colon, brain, ovary,
breast, prostate, and kidney. These cell
lines were selected partly on pragmatic
terms: those selected behaved best under
typical assay conditions. The screen was
designed so that for each compound
tested, both the absolute and the relative
sensitivities of individual cell lines were
reproducible to the extent that a characteristic
profile or fingerprint of cellular
response was generated.
Although the particular inhibitory
response of a single cell line might be
relatively uninformative, the pattern of
response of the cell lines as a group can
be used to rank a compound according
to the likelihood of sharing common
mechanisms. The COMPARE algorithm
(a computer program) qualifies this
pattern and searches an inventory of
screened agents to compile a list of the
compounds that have the most similar
patterns of cellular sensitivity and
resistance.
Extramural researchers who wish to
access this service should complete an
online submission form: http://dtp.nci.
nih.gov/compsub/index.html. Pure compounds
must be of known molecular
structure, and the investigator is required
to enter the molecular structure on the
online submission form before sending
samples of the test compound. Additional