| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Regular Articles |

From the Institute of Pathology,*
Ludwig Maximilians
University, Munich; and the Institute of Molecular
Virology,
GSF-National Research Center
for Environment and Health, Neuherberg, Germany
Fas and Fas-L regulate immune responses through the
induction of cell death. Fas-L is commonly expressed in activated
immune cells and in the endothelium. In the latter it contributes to
the inhibition of transvascular cell migration by the induction of
apoptosis in Fas-bearing lymphocytes. Here we investigated whether the
Fas/Fas-L system may regulate lymphocyte invasion into angiosarcomas.
Fas and Fas-L expression was quantitatively determined in different
grade angiosarcomas (n = 40) and related to the
number of extravasated tumor-infiltrating lymphocytes (TILs). Fas
expression was detected in <50% of the cases. In positive tumors both
the number of Fas-positive cells and the staining intensity were highly
variable and did not correlate with the number of TILs, the
mean time of survival, and the histopathological tumor grade.
By contrast, Fas-L expression was detected in >70% of the
cases and the relative numbers of Fas-L-positive cells correlated
inversely with the numbers of CD3- and CD8-positive TILs
(P
0.004). The survival times of patients with
high Fas-L-expressing angiosarcomas were significantly reduced as
compared to patients with low Fas-L-expressing tumors. Our results show
that angiosarcomas with low Fas-L expression are characterized by
numerous TILs, whereas sarcomas with high Fas-L expression show
significantly reduced numbers of TILs. These results suggest that the
Fas/Fas-L system may repress TIL invasion into angiosarcoma and by this
may contribute to the evasion of the anti-tumor immune surveillance of
angiosarcoma in the course of an apoptotic tumor counterattack
mechanism.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |