原发性鼻咽癌患者her2基因表达的意义

目的　探讨鼻咽癌her2基因在DNA水平的变化并弄清her2癌蛋白在部分鼻咽癌中过度表达的分子机制。方法　用间期荧光原位杂交（FISH）和免疫组织化学分析方法对45例原发性鼻咽癌及其癌旁正常组织her2基因在DNA和蛋白质水平的变化。结果　癌旁正常组织细胞核her2信号为1.92±0.10,有2个her2信号和2个17号着丝粒信号核占75.5%±9.3%；与之相比，45例鼻咽癌中无一例有her2基因拷贝数的变化；Her2癌蛋白过表达见于33%（15/45）。但各年龄、性别和不同临床分期鼻咽癌之间表达差异无显著意义。结论　Her2癌蛋白过表达与her2基因扩增无关，其产生机制及其生物学意义有待进一步探讨。

Significance of her2 oncogene expression in primary nasopharyngeal carcinoma

OBJECTIVE: To investigate the status of her2 oncogene at DNA level and the molecular mechanism of overexpression of her2 oncoprotein in part of patients with nasopharyngeal carcinoma (NPC). METHODS: Forty-five cases of PNC tissue and fifteen cases of normal epithelial tissue adjacent to tumor tissue were examined for her 2 signal and centromere 17 signal. Interphase fluorescence in situ hybridization (FISH) was used to examine the copy number of her 2 and immunohistochemical (IHC) staining were used to analyze the copy number and protein expression of her2. RESULTS: There were 1.92% +/- 0.10% her2 signals per nucleus in normal epithelial tissue adjacent to tumor. 75.52 +/- 9.33% of the nuclei contained 2 her2 signals and 2 centromere 17 signals. No alteration in gene copy number was found in cancerous nuclei. However, IHC staining of the 45 tumors with antibody against her2 showed that overexpression of her2 oncoprotein occurred in 33% (15/45) of NPC. However, there was no significant correlation between her2 expression and sex, age, clinical staging, and clinical outcome of patients. CONCLUSION: The overexpression of her2 in NPC does not relate to her2 gene amplification. Immunohistochemistry may not be a good measure to examine her2 expression. The mechanism of her2 oncoprotein overexpression and its biological significance in the development of NPC remain to be elucidated.