Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul, 90035-903 Porto Alegre, RS, Brazil.
J Oncol. 2012;2012:537861. doi: 10.1155/2012/537861. Epub 2012 Jul 8.
Gliomas are the most incident brain tumor in adults. This malignancy has very low survival rates, even when combining radio- and chemotherapy. Among the gliomas, glioblastoma multiforme (GBM) is the most common and aggressive type, and patients frequently relapse or become refractory to conventional therapies. The fact that such an aggressive tumor can arise in such a carefully orchestrated organ, where cellular proliferation is barely needed to maintain its function, is a question that has intrigued scientists until very recently, when the discovery of the existence of proliferative cells in the brain overcame such challenges. Even so, the precise origin of gliomas still remains elusive. Thanks to new advents in molecular biology, researchers have been able to depict the first steps of glioma formation and to accumulate knowledge about how neural stem cells and its progenitors become gliomas. Indeed, GBM are composed of a very heterogeneous population of cells, which exhibit a plethora of tumorigenic properties, supporting the presence of cancer stem cells (CSCs) in these tumors. This paper provides a comprehensive analysis of how gliomas initiate and progress, taking into account the role of epigenetic modulation in the crosstalk of cancer cells with their environment.
神经胶质瘤是成年人中最常见的脑肿瘤。这种恶性肿瘤的存活率非常低，即使结合放疗和化疗也是如此。在神经胶质瘤中，多形性胶质母细胞瘤（GBM）是最常见和侵袭性最强的类型，患者经常复发或对常规治疗产生耐药性。如此具有侵袭性的肿瘤能够在如此精心协调的器官中产生，而在该器官中，细胞增殖几乎不需要维持其功能，这一事实直到最近才引起科学家们的兴趣，当时发现大脑中存在增殖细胞克服了这些挑战。即便如此，神经胶质瘤的确切起源仍然难以捉摸。得益于分子生物学的新进展，研究人员能够描绘出神经胶质瘤形成的第一步，并积累了有关神经干细胞及其祖细胞如何成为神经胶质瘤的知识。事实上，GBM 由一群非常异质的细胞组成，这些细胞表现出多种致瘤特性，支持这些肿瘤中存在癌症干细胞（CSC）。本文综合分析了神经胶质瘤的发生和进展，考虑了表观遗传调控在癌细胞与其环境相互作用中的作用。
