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BIBTEX RIS

Microglial stress inducible protein 1 promotes proliferation and migration in human glioblastoma cells

2011; Elsevier BV; Volume: 200; Linguagem: Inglês

10.1016/j.neuroscience.2011.10.025

1873-7544

Anna Carolina Carvalho da Fonseca, Luciana Romão, Rackele Ferreira do Amaral, Suzana Assad Kahn, Denise S. Lobo, Sheila Cristina de Souza Martins, Jorge Marcondes de Souza, Vivaldo Moura‐Neto, Flávia Regina Souza Lima,

Nuclear Receptors and Signaling

Microglial activation is a key event in the progression and infiltration of tumors. We have previously demonstrated that the co-chaperone stress inducible protein 1 (STI1), a cellular prion protein (PrPC) ligand, promotes glioblastoma (GBM) proliferation. In the present study, we examined the influence of microglial STI1 in the growth and invasion of the human glioblastoma cell line GBM95. We demonstrated that soluble factors secreted by microglia into the culture medium (microglia conditioned medium; MG CM) caused a two-fold increase in the proliferation of GBM95 cells. This effect was reversed when STI1 was removed from the MG CM. In this context, we have shown that microglial cells synthesize and secrete STI1. Interestingly, no difference was observed in proliferation rates when GBM cells were maintained in MG CM or MG CM containing an anti-PrPC neutralizing antibody. Moreover, rec STI1 and rec STI1Δ230–245, which lack the PrPC binding site, both promoted similar levels of GBM95 proliferation. In the migration assays, MG CM favored the migration of GBM95 cells, but migration failed when STI1 was removed from the MG CM. We detected metalloproteinase 9 (MMP-9) activity in the MG CM, and when cultured microglia were treated with an anti-STI1 antibody, MMP-9 activity decreased. Our results suggest that STI1 is secreted by microglia and favors tumor growth and invasion through the participation of MMP-9 in a PrPC-independent manner.