Gomès D, de Néchaud B, Maunoury R, Moura Neto V, Brigaudeau C, Labrousse F, Dupouey P
Département d'Immunologie, Institut Pasteur, Paris, France.
Acta Neuropathol. 1997 Oct;94(4):376-84. doi: 10.1007/s004010050722.
A human glioma cell line, SA146, was initiated on precoated extracellular matrix from a stereotactic biopsy of a glioblastoma. We report modulation in the expression of glial fibrillary acidic protein (GFAP) by SA146 passed in vitro before or after xenogenic transplantation into nude mice. Immunofluorescence data show a decrease in the percentage of GFAP-expressing cells with increasing in vitro passages but a full reexpression (100% of GFAP-positive cells among vimentin-positive cells) was observed in cultures just derived from the xenotransplanted tumor. These changes are correlated with the mRNA content (Northern blot probed with a cDNA for GFAP) and with the protein level (cytoskeletal fraction analyzed by two-dimensional gel electrophoresis and Western blots probed with a monoclonal antibody). At the optimal level of GFAP expression, a large range of micro-heterogeneity in GFAP isoforms is reached for which post-translational events are clearly involved since mRNA translation in cell free system would provide at best three isomers. We suggest that SA146 would be an appropriate model to study the regulation of GFAP expression in the context of human glial tumor biology.
一种人类胶质瘤细胞系SA146，源自胶质母细胞瘤立体定向活检的预包被细胞外基质。我们报告了SA146在异种移植到裸鼠之前或之后体外传代时，胶质纤维酸性蛋白（GFAP）表达的调节情况。免疫荧光数据显示，随着体外传代次数的增加，GFAP表达细胞的百分比降低，但在刚从异种移植肿瘤中获得的培养物中观察到完全重新表达（波形蛋白阳性细胞中100%为GFAP阳性细胞）。这些变化与mRNA含量（用GFAP的cDNA进行Northern印迹杂交）以及蛋白质水平（通过二维凝胶电泳分析细胞骨架部分，并用单克隆抗体进行Western印迹杂交）相关。在GFAP表达的最佳水平，达到了GFAP异构体的大范围微异质性，其中明显涉及翻译后事件，因为无细胞系统中的mRNA翻译最多只能产生三种异构体。我们认为SA146将是研究人类神经胶质瘤生物学背景下GFAP表达调控的合适模型。
