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.