EFFECTS OF INTERLEUKIN-1 AND DEXAMETHASONE ON INTERLEUKIN-6 PRODUCTION AND GROWTH IN HUMAN MENINGIOMAS

Interleukin-6 (IL-6) has been shown to bf released by cultured human m eningioma cells and may be a positive or negative regulator of tumour growth, IL-6 protein acid mRNA levels hare been examined in a series o f meningiomas, In 14 cases, the results are compared with the effects of IL-6 and dexamethasone on growth and IL-6 secretion in vitro. Tumou rs with the highest in vivo IL-6 mRNA expression also showed maximum i nduction of IL-6 and increased cellular proliferation on IL-I stimulat ion in vitro. Dexamethasone decreased the LL-l-stimulated IL-6 release in all cases, Meningiomas which had little or no IL-6 message were re fractory to IL-1 control of IL-6, Remarkably, these formed the group o f meningiomas that increased their growth rate in response to dexameth asone. (C) 1997 John Wiley Sons, Ltd.