Expression of interleukin-6 and its effect on invasiveness in human glioma stem cells in vitro

Abstract

Objective To investigate the expression of interleukin-6 in glioma stem cells (GSCs) and its role in glioma stem cells invasion.Method GSCs from eight surgical glioma specimens were cultured and identified.Real-time RT-PCR and Enzyme-Linked Immunosorbent Assay were used to measure and compare the expression levels of IL-6 in GSCs and corresponding primary glioma cells (PGCs).Subsequently,IL-6 antibody or exogenous IL-6 was used in a Matrigel-invasion assay and effects of IL-6 on GSCs or PGCs invasiveness were then determined.Results Paired t-test showed that IL-6 mRNA and protein expression levels were significantly higher in GSCs than in PGCs from the identical tumor (t =2.578,v =7,P ＜0.05 and t =4.690,v =7,P ＜ 0.005,respectively).In Matrigel-invasion assay,PGCs and GSCs invasiveness markedly decreased after IL-6 was blocked with neutralizing antibody (t =3.105,v =7,P ＜ 0.05 and t =13.922,v =7,P ＜ 0.001,respectively),but significantly increased when exogenous IL-6 was added (t =-5.983,v =7,P ＜0.001 and t =-6.935,v =7,P ＜ 0.001,respectively).Conclusions The present study found that the IL-6 is overexpressed in GSCs and significantly augments GSCs invasiveness in vitro,suggesting a potential target in future therapy for GSCs rather than for their derivatives. Key words: Interleukin-6 ; Immunosuppression ; Glioma; Neoplastic stem cells ; Neoplasm invasiveness