C. Huettner et al., INTERLEUKIN-10 IS EXPRESSED IN HUMAN GLIOMAS IN-VIVO AND INCREASES GLIOMA CELL-PROLIFERATION AND MOTILITY IN-VITRO, Anticancer research, 17(5A), 1997, pp. 3217-3224
Interleukin 10 (IL-IO) is a cytokine with a broad spectrum of immunosu
ppressive activity, but it's role in the oncogenesis of solid tumors i
s still unclear: In previous experiments we have shown that IL-IO spec
ific mRNA is produced within glial rumors in vivo. The aim of the pres
ent study was to investigate the expression of the TL-IO protein in vi
vo and to identify the cells producing IL-10 within the tumor tissue.
Expression levels significantly increased with malignancy of the gliom
as. 87.5% of grade III and IV, but only 4% of grade II tumors expresse
d high levels of mRNA. Elevation of IL-IO serum levels was found in 11
% of low grade and in 63,6% of high grade glioma patients. In situ hyb
ridization analysis with combined immunohistochemistry revealed that.
a) IL-10 is not produced by infiltrating B-or T-lymphocytes, b) both m
icroglia and astroglia contributed to IL-10 expression in malignant gl
iomas in vivo. These data suggested the functional role of IL10 in gli
oma progression. Therefore, the effects of IL-10 on proliferation and
migration of glioma cells were determined in vitro. Two human glioma c
ell lines were grown as monolayer as well as spheroids in the presence
of different concentrations of IL-10. IL-10 increased cell proliferat
ion significantly in both culture systems with a dose optimum of 25 ng
/ml. Glioma cell motility was enhanced with 25 ng/ml as the optimal do
se. Adding the IL-10 specific antibody reversed both effects. We concl
ude from our data that IL-IO is involved in the progression of glial t
umors, especially in the enhancement of tumor cell proliferation and m
igration which promotes infiltration of the surrounding tissue.