Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
J Magn Reson Imaging. 2011 Apr;33(4):808-16. doi: 10.1002/jmri.22517.
To study choline metabolism in biopsies from nonenhancing Grade 2 (AS2) and Grade 3 (AS3) astrocytomas to determine whether (1) phosphocholine (PC) dominates in AS3, and (2) PC is associated with proliferation or angiogenesis. PC and glycerophosphocholine (GPC) are involved in phospholipid metabolism that accompanies mitosis. PC is the predominant peak in Grade 4 astrocytoma (GBM) while GPC dominates in AS2.
We used high resolution magic angle spinning magnetic resonance spectroscopy to compare the concentrations of 10 metabolites in 41 biopsies (16 AS2 and 25 AS3) from 24 tumors. Immunohistochemistry was performed on paired biopsies to determine the cell density, Ki-67 proliferation index, and vascular endothelial growth factor (VEGF) angiogenic marker expression.
AS3 had higher PC than AS2; however, the PC:GPC was less than 1 in all cases irrespective of tumor grade. Within tumors, GPC increased with Ki-67 and PC and tCho increased with cell density. There was no association between any choline compound and VEGF.
These data suggest that PC:GPC less than 1 is not unique to low grade glioma. Furthermore, the PC concentration that is a marker of aggressive glial tumors is not tightly linked to cell proliferation or angiogenesis in nonenhancing astrocytomas.
研究非增强性 2 级（AS2）和 3 级（AS3）星形细胞瘤活检组织中的胆碱代谢，以确定（1）PC 是否在 AS3 中占主导地位，以及（2）PC 是否与增殖或血管生成有关。PC 和甘油磷酸胆碱（GPC）参与伴随有有丝分裂的磷脂代谢。PC 是 4 级星形细胞瘤（GBM）的主要峰，而 GPC 在 AS2 中占主导地位。
我们使用高分辨率魔角旋转磁共振波谱法比较了 24 个肿瘤的 41 个活检标本（16 个 AS2 和 25 个 AS3）中的 10 种代谢物的浓度。对配对活检标本进行免疫组织化学染色，以确定细胞密度、Ki-67 增殖指数和血管内皮生长因子（VEGF）血管生成标志物的表达。
AS3 的 PC 高于 AS2；然而，无论肿瘤分级如何，所有病例的 PC：GPC 均小于 1。在肿瘤内，GPC 随着 Ki-67 和 PC 的增加而增加，tCho 随着细胞密度的增加而增加。任何胆碱化合物与 VEGF 之间均无相关性。
这些数据表明，PC：GPC 小于 1 并不独特于低级别胶质瘤。此外，作为侵袭性胶质肿瘤标志物的 PC 浓度与非增强性星形细胞瘤中的细胞增殖或血管生成没有紧密联系。
