Expression of the IL-6 family cytokines in human brain tumors

Oncostatin-M induction of vascular endothelial growth factor expression in astroglioma cells

“…The OSM effect on VEGF expression is further enhanced by IL1b. This novel mechanism of VEGF induction in astroglioma cells may offer a link between previous reports of elevated OSM and VEGF expression in gliomas (Pietsch et al, 1997;Chaudhry et al, 2001;Lilja et al, 2001;Hao et al, 2002), and suggest novel therapeutic targets in glioma treatment.…”

“…Up to 95% of astrogliomas produce VEGF (Pietsch et al, 1997), and there is a direct correlation between astroglioma grade and the level of VEGF production (Chaudhry et al, 2001;Yao et al, 2001). Astroglioma specimens also express increased OSM mRNA levels (Lilja et al, 2001;Hao et al, 2002), although the cell(s) of origin was not determined. Here, we show that GBM tumor biopsies also express elevated OSM protein levels ( Figure 7).…”

Inhibition of constitutively active Stat3 suppresses proliferation and induces apoptosis in glioblastoma multiforme cells

“…However, the Jakspecific tyrosine kinase inhibitor AG490 at a concentration of 50 mM completely abrogates Stat3 activation in U251 cells by 72 h suggesting that 50 mM AG490 also inhibits IL-6-independent activation of Stat3 in U251 cells. A recent study has shown that astrocytomas produce OSM and LIF that use Jaks for Stat3 activation (Lilja et al, 2001). Therefore, it remains to be examined if U251 and other GBM cells secrete OSM or LIF, and express their cognate receptors.…”

Oncostatin M-induced genes in human astrocytomas

“…We have previously reported OSM to be expressed in many brain tumor types and that the cytokine is produced by tumor cells (6). Further analysis showed that the tumor cells have functional OSM receptors and signal transduction systems, but the effects of OSM expression on proliferation, apoptosis and migration in brain tumors remain unclear (7,14,20,21).…”

“…Microglia, hypertrophic astrocytes and infiltrating leucocytes are sources of OSM (4,5). We have previously reported that OSM is expressed in human brain tumors and that the production stems from the neoplastic cells, but it remains unclear what effects OSM has in these tumors (6).…”