HUMAN ASTROCYTOMA-CELLS ARE CAPABLE OF PRODUCING MACROPHAGE INFLAMMATORY PROTEIN-1-BETA

We investigated expression of macrophage inflammatory protein-1 (MIP-1 ) alpha and beta in human astrocytoma cell lines and surgical specimen s of astrocytic tumors. Enzyme-l:inked immunosorbent assay (ELISA) sho wed constitutive secretion of MIP-1 alpha protein in only one and MIP- 1 beta in none of 7 cell lines tested. However, MIP-1 alpha production was increased in three cell lines by stimulation with lipopolysacchar ide (LPS) and 5 cell lines by stimulation with phorbol-12myristate-13- acetate (FMA). Also, induction of MIP-1 beta production was observed i n one cell line with LPS stimulation and in two cell lines with PMA st imulation. Reverse-transcription polymerase chain reaction (RT-PCR) sh owed the increase of MIP-1 alpha and beta mRNA expression in these cel l lines. The increase of the mRNA with the stimuli was further confirm ed by Northern blot analysis. In contrast, RT-PCR analysis revealed th at the majority of the tested tumor specimens of high-grade astrocytom as expressed both MIP-1 alpha and MIP-1 beta mRNAs. ELISA detected MIP -1 beta protein in 1 of 11 cerebrospinal fluid samples from patients w ith high-grade astrocytoma and in 8 of 9 tumor cyst fluid samples, whe reas MIP-1 alpha was detected in only 1 cyst fluid somple. Taken toget her, 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.