EXPRESSION OF INTERLEUKIN-1-BETA MESSENGER-RNA AND PROTEIN IN HUMAN GLIOMAS ASSESSED BY RT-PCR AND IMMUNOHISTOCHEMISTRY

To characterize the expression and localization of interleukin (IL)-1 beta in human gliomas, both reverse transcriptase-polymerase chain rea ction (RT-PCR) and immunohistochemistry were used on surgically excise d human,gliomas, human malignant glioma xenografts, and human glioblas toma cell lines. The RT-PCR products for IL-1 beta mRNA were quantifie d by computerized image analysis. IL-1 beta mRNA was detectable in 30 out of 35 (86%) surgically resected gliomas. An abundant expression of IL-1 beta mRNA was often found in the glioblastomas, anaplastic astro cytomas, and pilocytic astrocytomas, but not in other types of gliomas . Quantitatively, in both the grade 2 astrocytomas and the oligodendro gliomas, the IL-1 beta mRNA levels were significantly (p < 0.05) lower than those of the grade 3/4 astrocytomas. Immunohistochemically, IL-1 beta was localized in the pleomorphic tumor cells of the astrocytic t umors and in macrophages. In contrast to the astrocytic tumors, low an d high grade oligodendrogliomas showed no or little expression of IL-1 beta antigen, IL-1 beta was present less frequently than IL-1 alpha a nd IL-1 receptor type 1 in 3 malignant gliomas transplanted into nude mice by RT-PCR. All 2 cell lines showed IL-1 beta expression at both t he mRNA and protein levels. It is concluded that in human gliomas, bot h high-grade astrocytomas and pilocytic astrocytomas often express hig h IL-1 beta production, and that IL-1 beta is mainly localized in astr ocytic tumor cells and macrophages.