Abstract Book 2010 - CIMT Annual Meeting

080 Flores-Guzman | Tumor biology & interaction with the immune system
Potential cancer stem cells in ret transgenic mouse model of
spontaneous melanoma
Fernando Flores-Guzman, Dirk Schadendorf and Viktor Umansky
German Cancer Reserarch Center (DKFZ), Heidelberg, Germany
The cancer stem cell (CSC) hypothesis suggests that
neoplastic clones are maintained exclusively by a
rare fraction of tumor cells with stem cells properties.
CSC could represent disseminated dormant tumor
cells without clinical signs of progression. We used a
transgenic mouse spontaneous melanoma model, in
which after a short latency, around 25% of all transgenic
mice developed skin tumors with metastases
in distant organs like liver and lungs. We found that
CD133+ melanoma cells represent a small subset in
primary skin tumors and lymph node metastases
(< 1.5%). The amount of CD133+ melanoma cells
both in primary skin tumors and lymph node metastases
correlated with the primary tumor weight
and the stage of tumor progression. We detected
TRP2+CD133+ single melanoma cells in the bone
marrow of tumor bearing mice suggesting thereby
that these cells could be potential melanoma stem
cells. We also found CD20, CD24, CD44 and CD166
expression in primary tumors, which correlated
with the tumor progression. Another potential melanoma
stem cell marker nestin was express in most
melanoma cells, whereas the multidrug resistance
ABCB5 marker was expressed on less than 3% cells
from primary skin tumors.
In conclusion, our data demonstrate an existence
of the subpopulation of CD133+ melanoma cells in
primary skin tumors, metastatic lymph nodes and
in the bone marrow of tumor bearing transgenic
mice and suggest that these subsets could be potential
CSC.
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