摘要目的观察视网膜母细胞瘤(retinoblastoma, RB) Fas/Fas配体 (Fas ligand ,FasL)表达及与凋亡的相关性。方法应用免疫组织化学染色法观察32例RB标本中 Fas/FasL的表达及分布,并对32例用光镜、其中4例用电镜及12例用末端脱氧核苷酸转移酶介导的生物素化脱氧尿苷三磷酸末端标记 (terminal deoxynucleotidyl transferase mediated biotin-dUTP nick-end labeling, TUNEL)染色观察细胞凋亡，分析与Fas/FasL表达的关系。结果光镜下凋亡细胞主要位于RB退化区，电镜下可见染色质边集和凋亡小体等凋亡特征； TUNEL显示阳性标识主要位于RB退化区及死亡区。Fas及 FasL在所有RB中均呈阳性表达。Fas和 FasL表达与凋亡指数 (apoptosis index, AI)呈正相关 (P<0．01，P＜0．001)。结论凋亡在RB中普遍存在，可能是触发RB细胞死亡的主要方式；Fas系统在RB的发生发展中起重要作用。Fas系统上调可能会诱导RB细胞凋亡。

abstractsObjective　To investigate the correlation of expression of Fas/Fas ligand (FasL) and apoptosis in retinoblastoma (RB)．　Methods　The expression and distribution of Fas/FasL were detected by using immunohistochemical staining in 32 cases of RB． Light microscopy (32 cases), electron microscopy (4 cases) and TdT mediated biotin-dUTP nick-end labeling (TUNEL) (12 cases) were used to study apoptosis in RB．　Results　Apoptotic RB cells mostly located at RB regress area． Chromatin margination and apoptotic bodies were found in RB． TUNEL positive labeling cells especially located in tumor regress area． Positive immunolabeling for Fas and FasL was found in all RB specimens． There was a highly significant and positive correlation between the expression of Fas/FasL and apoptotic indices (AI) (P<0．01 or 0．001)．　Conclusion　The results suggest that apoptotic cell death is prevalent in RB and it may be one type of the most dominant cell death． Fas system may play an important role in oncogenesis and progression of RB, and the up-regulation of Fas system expression might induce RB cell apoptosis．