An Example of
Pathology-Model Based Target Validation
Background:In vitro studies
had shown that molecule y could stimulate proliferation of
peripheral blood lymphocytes and increase cytotoxicity of NK
cells. In the absence of a suitable antibody, a RNA probe was
generated for fast ISH tissue profiling. The purpose of
the ISH analysis was to determine the origin of
molecule y and to identify any disease processes that might be
associated with the molecule.
Procedures
Results
Picture
Probe production
In vitro transcription produced
high quality RNA probe (1 - sense template; 2- anti-sense
template; 3 - sense RNA probe; 4 - anti-sense RNA probe).
ISH tissue profiling was performed
in standard normal tissue and caner arrays, and our inflammatory
pathology model.
ISH tissue profiling
showed a unique distribution of molecule y in normal tissues
(blue bars) and
increased levels (of the molecule) in a wide
range of inflammatory (red bars) and cancerous (yellow bars)
conditions
ISH tissue profiling of
molecule y in normal tissue arrays.
Picture shows high expression of
molecule y (black-brown staining indicated by blue arrows) in
small intestine Paneth cells that are thought to secret
molecules for regulation of microbial flora in the gut.
ISH tissue analysis of
molecule y in inflammatory pathology model.
The
right picture shows high expression level of molecule y in
the infiltrating lymphocytes (black staining indicated by
blue arrows) of a case of inflammatory bowl disease.
ISH tissue analysis of
molecule y in inflammatory pathology model.
The
right picture shows high level of molecule y in the regenerating
epithelial cells (black staining indicated by blue arrows) in a
case of chronic thyroiditis.
ISH tissue profiling of
molecule y in cancer tissue arrays.
The
right picture shows high level of molecule y in the infiltrating
lymphocytes (black staining indicated by blue arrows) and mild
level in the cancer cells (right lower part) in a case of colon
cancer.
Summary & Conclusion
In normal
tissues, molecule y was detected in Paneth cells of the small
intestine, epithelial cells of the prostate and germ cells of
the testes. Increased levels of the molecule were observed in a
wide range of inflammatory and cancerous conditions including
lymphocytes of the reactive lymph node/tonsil, crohn disease,
ulcerative colitis, regenerating epithelial cells of chronic
thyroiditis, and infiltrating lymphocytes and tumor cells
of many tumor types. The increased levels demonstrated in these
conditions indicate that the expression of molecule y may
be associated with inflammation and general cell stress.