胶质瘤干细胞可诱导宿主肝组织内胶质瘤间质细胞恶性转化

Malignant transformation of glioma stromal cells induced by glioma stem cells heterotopically inoculated in host liver

目的 在已报道的原位移植的胶质瘤间质细胞可发生恶性转化的基础上,进一步探索该转化的发生是否依赖肿瘤部位特异性微环境.方法 将转有红色荧光蛋白（RFP）基因的人胶质瘤干/祖细胞SU3-RFP接种于全身表达绿色荧光蛋白（GFP）的裸小鼠肝脏,致瘤后取移植瘤组织做常规病理检测和细胞培养,单克隆具永生化的GFP＋,GFP＋/RFP＋细胞传代,做细胞表型分析和致瘤实验.结果 SU3-RFP的移植成功率约83％,经异位生长的移植瘤组织再培养获得永生化的间质细胞.已建立B4,B9,B10三株单克隆细胞株,其中BB4为共表达GFP/RFP的融合细胞,还同时表达CD1a、CD83、CD86等树突状细胞标志蛋白;B9表达GFP和巨噬细胞标志蛋白CD68、F4/80;B10表达GFP和成纤维细胞标志蛋白FAP-α、α-SMA、S100均为鼠源宿主细胞.3株细胞遗传学检测都是异倍体,在裸小鼠皮下致瘤率均为100％.结论 在裸小鼠肝组织内建立的胶质瘤异位移植模型中,胶质瘤间质细胞也能恶性转化,表明这种恶性转化在中枢神经系统之外亦能发生,而且由间质细胞恶性转化可引起肿瘤异质性,这对进一步研究肿瘤发生、演进与肿瘤微环境的关系具有重要意义.

Objective Tumor stromal cells have the potential of undergoing malignant transformation induced by glioma stem cells （GSCs） in orthotopic glioma model.The purpose of this study was to explore whether malignant transformation of tumor stromal cells induced by GSCs is dependent on specific local microenvironment.Methods Human glioma stem/progenitor cell line SU3 transfected with red fluorescent protein （SU3-RFP） gene were implanted into the liver of nude mice with whole-body expressing green fluorescence protein （GFP）.Then hepatic tumors were harvested to prepare single cell suspension and analyzed with routine pathological examinations.GFP cells with high proliferative abilities were obtained from the cultivation of single cell suspension.Immortalized glioma stromal cells only expressing GFP and double expressing GFP/RFP were further monocloned with micro-pipetting techniques and under continuous passages.Cell phenotypic analysis and tumorigenicity tests were also performed.Results SU3-RFP was transplanted into liver with a tumor formation rate of 83%.Immortalized glioma stromal cells were obtained from re-cultured xenograft tumor tissue.Three monoclonal cell lines B4,B9,B10 were established and proved to be host-derived cells.B4 was found to be a fusion cell co-expressing GFP/RFP and dendritic cell markers CD1a,CD83 and CD86.Both B9 and B10 were GFP＋ cells.B9 expressed macrophage markers CD68 and F4/80 while B10 produced fibroblast marker proteins FAP-α,α-SMA and S100.Three cells were all aneuploid with a tumorigenicity rate of 100% in nude mice.Conclusion Tumor stromal cells have the potential of malignant transformation in a heterotopic xenograft glioma model.Malignant transformation may also occur outside the central nervous system and contribute to tumor heterogeneity.Further studies are warranted for elucidating the relationship between tumorigenesis,evolution and tumor microenvironment.