Characterization of a side population of astrocytoma cells in response to temozolomide
Characterization of a side population of astrocytoma cells in response to temozolomide
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DOI：
10.3171/jns/2008/109/11/0856
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发表时间：
2008-11-01
影响因子：
4.1
通讯作者：
Tang, Carol
中科院分区：
文献类型：
--
作者：
Chua, Constance;Zaiden, Norazean;Tang, Carol
对象。通过Hoechst 33342染料外排分离的癌症祖细胞样细胞（称为“侧群”[SP]）已在多种癌症中进行了研究，包括恶性脑肿瘤。在这项研究中，作者研究了2种胶质瘤细胞系SP表型的性质。U87MG和T98G对替莫唑胺的反应。本文还研究了SP细胞表达的几种三磷酸腺苷结合盒（ABC）多药转运体，特别是ABCG2的作用。采用荧光活化细胞分选。将细胞分成SP和非SP两部分，采用免疫荧光染色、实时定量聚合酶链反应分析祖细胞样性质。以及它们在免疫功能受损的小鼠体内改造神经胶质瘤团块的能力。从细胞和分子水平研究SP细胞对替莫唑胺的反应。用小干扰RNA敲除法检测ABCG2转运体的特异性作用，用软琼脂致克隆法检测细胞的致瘤潜能。侧群细胞的特点是存在祖细胞样特性：巢蛋白、musashi-1的表达增加。和ABCG2。此外。只有SP细胞能够重建细胞异质性，这些细胞也比非SP细胞更具侵袭性，并具有致瘤能力。替莫唑胺处理使SP细胞数量增加。这与更多的祖细胞相对应。同时伴有几种ABC转运蛋白的表达升高。ABCG2转运蛋白的敲除并未消除SP细胞对替莫唑胺的反应。其他几个ABC药物转运基因的上调被认为是这种化学耐药的原因。
Object. Cancer progenitor-like cells isolated by Hoechst 33342 dye efflux (termed the "side Population" [SP]) have been Studied in a variety of cancers, including malignant brain tumors. In this study, the authors investigate the nature of the SP phenotype in 2 glioma cell lines. U87MG and T98G, and their response to temozolomide. The roles of several adenosine triphosphate-bindin cassette (ABC) multidrug transporters expressed by SP cells, in particular ABCG2, are also examined.Methods. Using fluorescence-activated cell sorting. the cells were separated into SP and non-SP fractions and analyzed for progenitor cell-like properties with immunofluorescence staining, quantitative real-time polymerase chain reaction. and their ability to reform glioma mass in an immune-compromised mouse. The response of the SP cells to temozolomide was investigated at the cellular and molecular levels. Small interfering RNA knockdown was used to examine the specific role of the ABCG2 transporter, and the cells' tumorigenic potential was measured using the soft agar clonogenic assay.Results. Side Population cells are characterized by the presence of progenitor cell-like properties: increased expression of nestin, musashi-1. and ABCG2 were observed. In addition. only SP cells were able to reconstitute cellular heterogeneity: these cells were also more invasive than the non-SP cells, and possessed tumorigenic capacity. Temozolomide treatment increased the number of SP cells. and this corresponded to more progenitor-like cells. concurrent with elevated expression of several ABC transporters.Conclusions. Knockdown of ABCG2 transporters did not abrogate the SP cell response to temozolomide. Upregulation of several other ABC drug transporter genes is proposed to account for this chemoresistance.