Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Bat. B23, Liege, Belgium.
J Proteome Res. 2012 Oct 5;11(10):5011-21. doi: 10.1021/pr3005698. Epub 2012 Sep 4.
High-grade gliomas (glioblastomas) are the most common and deadly brain tumors in adults, currently with no satisfactory treatment available. Apart from de novo glioblastoma, it is currently accepted that these malignancies mainly progress from lower grade glial tumors. However, the molecular entities governing the progression of gliomas are poorly understood. Extracellular and membrane proteins are key biomolecules found at the cell-to-cell communication interface and hence are a promising proteome subpopulation that could help understand the development of glioma. Accordingly, the current study aims at identifying new protein markers of human glioma progression. For this purpose, we used glial tumors generated orthotopically with T98G and U373 human glioma cells in nude mice. This setup allowed also to discriminate the protein origin, namely, human (tumor) or mouse (host). Extracellular and membrane proteins were selectively purified using biotinylation followed by streptavidin affinity chromatography. Isolated proteins were digested and then identified and quantified employing 2D-nano-HPLC-MS/MS analysis. A total of 23 and 27 up-regulated extracellular and membrane proteins were identified in the T98G and U373 models, respectively. Approximately two-thirds of these were predominantly produced by the tumor, whereas the remaining proteins appeared to be mainly overexpressed by the host tissue. Following extensive validation, we have focused our attention on sparc-like protein 1. This protein was further investigated using immunohistochemistry in a large collection of human glioma samples of different grades. The results showed that sparc-like protein 1 expression correlates with glioma grade, suggesting the possible role for this protein in the progression of this malignancy.
高级别神经胶质瘤（胶质母细胞瘤）是成人中最常见和最致命的脑肿瘤，目前尚无令人满意的治疗方法。除了新发生的胶质母细胞瘤外，目前公认这些恶性肿瘤主要由低级别的神经胶质瘤进展而来。然而，调控神经胶质瘤进展的分子实体尚未被充分了解。细胞间通讯界面的关键生物分子是细胞外和膜蛋白，因此，它们是一个很有前途的蛋白质组亚群，有助于理解神经胶质瘤的发生。因此，本研究旨在鉴定人类神经胶质瘤进展的新的蛋白质标志物。为此，我们使用 T98G 和 U373 人神经胶质瘤细胞在裸鼠中原位生成的神经胶质瘤进行研究。这种方法还可以区分蛋白质的来源，即人类（肿瘤）或小鼠（宿主）。使用生物素化和链霉亲和素亲和层析法选择性地纯化细胞外和膜蛋白。分离的蛋白质被消化，然后使用二维纳升 HPLC-MS/MS 分析进行鉴定和定量。在 T98G 和 U373 模型中分别鉴定到 23 种和 27 种上调的细胞外和膜蛋白。这些蛋白中约有三分之二主要由肿瘤产生，而其余的蛋白似乎主要由宿主组织过度表达。经过广泛验证，我们将注意力集中在类基质金属蛋白酶 1 上。在不同分级的大量人类神经胶质瘤样本中，我们使用免疫组织化学进一步研究了这种蛋白。结果表明，类基质金属蛋白酶 1 的表达与神经胶质瘤的分级相关，提示该蛋白可能在这种恶性肿瘤的进展中起作用。
