Allan K, Jordan R C, Ang L C, Taylor M, Young B
Department of Pathology, Sunnybrook and Women's College Health Science Center, University of Toronto, Toronto, Ontario.
Arch Pathol Lab Med. 2000 Feb;124(2):216-20. doi: 10.5858/2000-124-0216-OOCAAC.
Cyclins are proteins that are expressed during the progression of a normal cell through the cell cycle. In a number of cancers, overexpression of cyclin A and cyclin B1 proteins has been reported, and in some instances the levels of expression correlated well with the grades of malignancy. The expression of cyclin A and cyclin B1 proteins in astrocytoma may be linked to the histologic grade or proliferative activities.
To study the expression of cyclin A and cyclin B1 proteins in astrocytomas and correlate the labeling indices (LIs) of cyclin A and cyclin B1 with histologic grade and Ki-67 LI.
The surgical biopsy specimens from 65 adults with astrocytomas were reviewed and divided into grades based on the World Health Organization system. The paraffin sections were immunostained using primary antibodies against Ki-67, cyclin A, and cyclin B1. The LIs of these astrocytomas for the 3 different antibodies were determined by computerized image analysis.
The cyclin A LI showed good correlation with astrocytoma grade and Ki-67 LI. Both the nuclear and cytoplasmic cyclin B LIs correlated well with the tumor grade but showed poor correlation with Ki-67 LI.
This study suggests that although both cyclin A and B protein expression are related to the grade of malignancy in astrocytomas, cyclin A levels more generally reflect the proliferative state of these tumors. We also provide indirect evidence that cyclin B1 is associated with the aberrant progression through the G2-M phase checkpoint in astrocytomas.
细胞周期蛋白是正常细胞在细胞周期进程中表达的蛋白质。在多种癌症中，已有报道细胞周期蛋白A和细胞周期蛋白B1蛋白过表达，在某些情况下，表达水平与恶性程度分级密切相关。星形细胞瘤中细胞周期蛋白A和细胞周期蛋白B1蛋白的表达可能与组织学分级或增殖活性有关。
研究细胞周期蛋白A和细胞周期蛋白B1蛋白在星形细胞瘤中的表达，并将细胞周期蛋白A和细胞周期蛋白B1的标记指数（LIs）与组织学分级和Ki-67标记指数相关联。
回顾性分析65例成年星形细胞瘤患者的手术活检标本，并根据世界卫生组织系统进行分级。石蜡切片用抗Ki-67、细胞周期蛋白A和细胞周期蛋白B1的一抗进行免疫染色。通过计算机图像分析确定这些星形细胞瘤对3种不同抗体的标记指数。
细胞周期蛋白A标记指数与星形细胞瘤分级和Ki-67标记指数显示出良好的相关性。细胞核和细胞质中的细胞周期蛋白B标记指数均与肿瘤分级密切相关，但与Ki-67标记指数相关性较差。
本研究表明，虽然细胞周期蛋白A和B的蛋白表达均与星形细胞瘤的恶性程度分级有关，但细胞周期蛋白A水平更普遍地反映了这些肿瘤的增殖状态。我们还提供了间接证据，表明细胞周期蛋白B1与星形细胞瘤中G2-M期检查点的异常进程有关。
