鼻咽癌癌前及其高危人群鼻咽上皮组织EB病毒DNA酶基因检测

The examination of EBV DNase gene fragment in the paraffin embedded NPC, pre cancerous and high risk population nasopharyngeal tissues

目的探讨非癌鼻咽上皮细胞发展为鼻咽癌（ＮＰＣ）的过程中，ＥＢ病毒在什么阶段进入鼻咽上皮。方法利用广州中山医科大学肿瘤防治中心四会县防癌基地１９９４年度复查工作及肿瘤医院门诊，收集鼻咽癌及各类“癌前状态”及“癌前病变”患者蜡块４５０余例，应用改进后的多聚酶链反应（ＰＣＲ）方法进行ＥＢＶＤＮＡ酶基因片段扩增检测。结果ＮＰＣ浸润癌组织ＥＢＶＤＮＡ酶基因片段扩增阳性率为９７．３％（１４５／１４９），ＮＰＣ原位癌４例中，基因阳性者２例，而防癌基地“癌前状态”人群１５５例中阳性者２例，阳性率为１．３％（２／１５５）。临床癌前病变组阳性率为零（０／４７）。结论ＥＢ病毒在非癌鼻咽组织中出现频率十分低，ＥＢ病毒可能在鼻咽上皮癌变后才进入鼻咽上皮，提示ＥＢ病毒可能不是ＮＰＣ的病因。

Objective To examine if EB virus enters nasopharyngeal epithelial cells in the course of the tumorigenesis in nasopharyngeal carcinoma (NPC). Methods Based on the annual investigation of Si Hui county, a cancer prevention base of the Sun Yet sen University of Medical Sciences and Tumour Hospital out patient clinic, more than 450 paraffin embedded tissues with NPC, and with pre cancerous lesions in high risk populations were collected for the detection of EBV DNase gene fragment by an optimized PCR method. Results In 145 of the 149(97.3%) cases with invasive NPC, and 2 of 4 cases with in situ NPC, EBV DNase gene was detected. However, in Sihui, Canton, a high risk county for NPC, only 2 of the 155 subjects with nasopharyngeal precancerous state was the gene positive, and none of the 47 cases examined in the out patient department of the Tumor Hospital with precancerous lesions in the nasopharynx was positive. Conclusion EBV is seldomly detected in the non malignant and precancerous lesions in the nasopharynx in high risk populations. It implies that EBV is probably not etiologically involved in the genesis of NPC.