Schiffer D, Cavalla P, Migheli A, Giordana M T, Chiadò-Piat L
Department of Neurology, University of Turin, Italy.
J Neurooncol. 1996 Feb;27(2):101-9. doi: 10.1007/BF00177472.
Bcl-2 proto-oncogene prevents apoptosis in many conditions. First detected in lymphomas, it has been also described in non-lymphoid tissues. The immunohistochemical distribution of bcl-2 protein in 100 neuroepithelial tumors is presented. Bcl-2 was positive in some neurons of normal nervous tissue, in reactive astrocytes and variably in all neuroepithelial tumor. The reaction product was either diffuse or granular, due to bcl-21 protein localization on cytoplasmic, nuclear and mitochondrial membranes. The positivity was high in medulloblastomas and in astrocytic tumors. In the latter, the strongest staining was found in cells retaining the astrocytic aspect. Oligodendroglial cells were minimally stained. No correlation of bcl-2 staining with survival was found in each tumor type. The interpretation of the results is based on the one side on the constitutive role played by bcl-2 in the nervous tissue and its neoplastic derivatives. On the other side, in tumors bcl-2 acts by preventing tumor cells from undergoing apoptosis. BCl-2 expression in brain tumors, therefore, receives a dual interpretation. For this reason and for the lacking of correlation with survival, bcl-2 expression cannot be regarded as a prognostic factor.
Bcl-2原癌基因在多种情况下可防止细胞凋亡。它最初在淋巴瘤中被检测到，也在非淋巴组织中有所描述。本文呈现了100例神经上皮肿瘤中bcl-2蛋白的免疫组化分布情况。Bcl-2在正常神经组织的一些神经元、反应性星形胶质细胞中呈阳性，在所有神经上皮肿瘤中呈阳性的情况各不相同。由于bcl-21蛋白定位于细胞质、细胞核和线粒体膜上，反应产物呈弥漫性或颗粒状。在髓母细胞瘤和星形细胞瘤中阳性率较高。在星形细胞瘤中，染色最强的是保留星形细胞形态的细胞。少突胶质细胞染色最少。在每种肿瘤类型中均未发现bcl-2染色与生存率之间存在相关性。对结果的解释一方面基于bcl-2在神经组织及其肿瘤衍生物中所起的组成性作用。另一方面，在肿瘤中bcl-2通过防止肿瘤细胞发生凋亡起作用。因此，脑肿瘤中BCl-2的表达有双重解释。基于这个原因以及与生存率缺乏相关性，bcl-2表达不能被视为一个预后因素。
