EN
The tumor microenvironment plays a critical
role in the survival, growth, invasion, and metastasis
of solid tumors. However, the mechanisms by which it
influences these aspects of tumor progression remain
incompletely characterized. In this study, we show that
human glioblastoma cells secrete soluble factors that
alter the phenotype and cytokine secretion profile of
both macrophages and mesenchymal stem cells (MSCs).
Macrophages and MSCs respond to tumor-secreted factors
by increasing the release of interleukin-6 (IL-6) and this
response is potentiated when macrophages and MSCs
are combined in co-culture. In glioblastoma, IL-6 has
been associated with tumor cell invasion, angiogenesis,
tumor cell proliferation, immune suppression, and poor
prognosis. Our results suggest that the orchestrated
response of macrophages and stromal elements to
neoplastic cells enhances tumor progression through the
release of soluble factors.