喉癌患者血浆DNA微卫星等位基因杂合型缺失的监测及意义

目的：分析喉癌患者肿瘤DNA微卫星多态位点等位基因杂合型缺失在肿瘤组织与血浆的表达及关系，探讨血浆肿瘤DNA的动态变化在临床早期诊断、筛查及随访中的意义。方法:2003年9月～2004年12月青岛大学医学院附属烟台毓璜顶医院耳鼻咽喉头颈外科喉癌患者43例，抽取术前、术后防凝血，分离淋巴细胞和血浆，采集肿瘤、癌旁组织标本，分别提取DNA。选取头颈部鳞状细胞癌等位基因杂合型缺失（LOH）表达较高的3个微卫星多态位点D9S162、D9S1782、D17S1665,设计并合成引物，PCR扩增，聚丙烯酰胺电泳，用ID Image Analysis Software 凝胶成像分析系统分析电泳结果。结果:D9S162肿瘤、术前血浆、术后血浆LOH表达率分别为51.85%，44.44%，33.33%；D9S1782分别为43.48%，39.13%，34.78%；D17S1665分别为51.43%，42.86%，37.14%。术后血浆3个位点有6位次LOH消失；早期和晚期喉癌血浆DNA的LOH表达无统计学差异（P＞0.05）。结论:肿瘤DNA的LOH的表达与血浆肿瘤DNA的表达一致，监测血浆肿瘤DNA的变化有助于喉癌的早期诊断，术后随访过程中动态监测血浆肿瘤DNA可以预测肿瘤有无复发或再发。

Survillance and significance of microsatillite heterozygosity loss in plasma tumor-derived DNA for laryngeal carcinoma

To analyze the expression of loss of hererozygosity (LOH) of tumor DNA and plasma DNA, and to investigate their relations. To explore the value of microsatillite change of plasma DNA on the early diagnosis, screening and follow up. Methods: Forty three cases of laryngeal cancer treated surgically were analyzed. Preoperative and postoperative blood (10 ml), tumor tissue, para tumor tissue were collected. The lymphocyte and plasma were separated. And the DNA was extracted respectively. Three loci with high occurrence, D9S162, D9S1782 and D17S1665 were selected, and the primer was projected and composed. The electrophoresis was analyzed with ID Image Analysis Software. Results: The LOH incidence of tumor, preoperative plasma, postoperative plasma for D9S162 was 51.85%， 44.44% and 33.33%； for D9S1782 was 43.48%, 39.13% and 34.78%； and for D17S1665 was 51.43%, 42.86% and 37.14% respectrively. LOH of 6 loci disappeared. There was no significant difference for LOH between early and advanced laryngeal cancers（P＞0.05）.Conclusions: The plasma LOH expression is coincident with the tumor.