Yee D, Hao C, Cheung H C, Chen H T, Dabbagh L, Hanson J, Coupland R, Petruk K C, Fulton D, Roa W H
Department of Oncology, Cross Cancer Institute/University of Alberta, Edmonton.
Clin Invest Med. 2001 Apr;24(2):76-82.
Glioblastoma cells produce cytokines with proinflammatory or immunosuppressive properties, or both, which, in addition to altered p53 gene expression, have been shown to be associated with glioblastoma resistance to radiotherapy. The reported data concerning cytokines have been isolated and sometimes discordant, and a comprehensive profile analysis of cytokines and their corresponding receptors in irradiated glioblastomas has received limited attention. The object of this study was to test the hypothesis that radiation alone in clinically relevant doses would not significantly alter expression of endogenous cytokines and their receptors in human glioblastoma celll ines with wild-type and mutant p53.
Culture specimens of 4 glioblastoma cell lines of different p53 gene expression (U87, U118, U251, U373) were irradiated with cobalt 60 at a dose of 10 Gy. After 48 hours, radiosensitivity was defined through a colony formation assay, cell cycle distribution was analyzed by flow cytometry, and cytokine and cytokine receptor messenger-RNA (mRNA) profiles were defined with an RNase protection assay. Different single doses of radiation at varying time intervals after culture were applied also to wild-type p53 cell lines.
All cell lines were relatively radioresistant at lower doses of 1 and 2 Gy. Immunosuppressive cytokine and cytokine receptor mRNA of the Th2 (IL-13Ralpha, IL-4) and Th3 family (TGF-beta1, 2 and 3, TGF-betaRI and RII) were expressed. In contrast, only 2 proinflammatory Th1 cytokine receptor genes (IFN-gammaRa and IFN-gammaRbeta), but no significant Th1 cytokine gene expression, were detected. Even though the population examined included a large fraction of reproductively dead cells, cytokine and cytokine receptor mRNA profiles were not altered significantly by irradiation in all cell lines, regardless of the p53 status.
These results suggest that cobalt irradiation alone at clinically relevant doses does not significantly alter the cytokine and cytokine receptor profiles in human glioblastoma cell lines.
胶质母细胞瘤细胞会产生具有促炎或免疫抑制特性的细胞因子，或者兼具二者，除了p53基因表达改变外，这些细胞因子还被证明与胶质母细胞瘤对放疗的抗性有关。关于细胞因子的已报道数据较为零散，有时还相互矛盾，而对接受照射的胶质母细胞瘤中细胞因子及其相应受体进行全面的谱分析受到的关注有限。本研究的目的是检验这样一个假设：临床相关剂量的单纯放疗不会显著改变野生型和突变型p53的人胶质母细胞瘤细胞系中内源性细胞因子及其受体的表达。
用钴60以10 Gy的剂量照射4种不同p53基因表达的胶质母细胞瘤细胞系（U87、U118、U251、U373）的培养标本。48小时后，通过集落形成试验确定放射敏感性，用流式细胞术分析细胞周期分布，并用核糖核酸酶保护试验确定细胞因子和细胞因子受体信使核糖核酸（mRNA）谱。在培养后的不同时间间隔，也对野生型p53细胞系施加不同的单剂量辐射。
所有细胞系在1 Gy和2 Gy的较低剂量下都具有相对的放射抗性。表达了Th2（IL-13Rα、IL-4）和Th3家族（TGF-β1、2和3、TGF-βRI和RII）的免疫抑制细胞因子和细胞因子受体mRNA。相比之下，仅检测到2种促炎Th1细胞因子受体基因（IFN-γRα和IFN-γRβ），但未检测到显著的Th1细胞因子基因表达。尽管所检测的群体中包括很大一部分生殖性死亡细胞，但无论p53状态如何，所有细胞系中的细胞因子和细胞因子受体mRNA谱都不会因照射而发生显著改变。
这些结果表明，临床相关剂量的单纯钴照射不会显著改变人胶质母细胞瘤细胞系中的细胞因子和细胞因子受体谱。
