Human astrocytoma cells are capable of producing macrophage inflammatory protein-1beta

We investigated expression of macrophage inflammatory protein-1 (MIP-1) alpha and beta in human astrocytoma cell lines and surgical specimens of astrocytic tumors. Enzyme-linked immunosorbent assay (ELISA) showed constitutive secretion of MIP-1alpha protein in only one and MIP-1beta in none of 7 cell lines tested. However, MIP-1alpha production was increased in three cell lines by stimulation with lipopolysaccharide (LPS) and 5 cell lines by stimulation with phorbol-12myristate-13-acetate (PMA). Also, induction of MIP-1beta production was observed in one cell line with LPS stimulation and in two cell lines with PMA stimulation. Reverse-transcription polymerase chain reaction (RT-PCR) showed the increase of MIP-1alpha and beta mRNA expression in these cell lines. The increase of the mRNA with the stimuli was further confirmed by Northern blot analysis. In contrast, RT-PCR analysis revealed that the majority of the tested tumor specimens of high-grade.astrocytomas expressed both MIP-1alpha and MIP-1beta mRNAs. ELISA detected MIP-1beta protein in 1 of 11 cerebrospinal fluid samples from patients with high-grade astrocytoma and in 8 of 9 tumor cyst fluid samples, whereas MIP-1alpha was detected in only 1 cyst fluid somple. Taken together, these results indicate that astrocytic tumor cells are capable of expressing and producing MIPs, and suggest that MIPs may participate in the inflammatory responses commonly seen in astrocytic tumors.