头颈部鳞癌微卫星多态标记的分析

Microsatellite Instability and Loss of Heterozygosity in Squamous Cell Carcinoma of the Head and Neck

目的 探讨中国人头颈部鳞状细胞癌 (SCCHN)多染色体上等位基因的杂合性丢失 (L OH)和微卫星不稳定 (MI)的频率。方法 采用聚合酶链反应结合二核苷酸的重复序列多态性方法 ,选取 6对染色体 (3p,4q,7q,9p,17p和 18q)上 18个微卫星位点对 30例 SCCHN手术配对组织进行分析。结果 30例 SCCHN组织中有 12例 (4 0 % )组织至少有一个微卫星位点发生 L OH,多数位点 L OH的频率普遍比已报道的文献低。有 7个位点(D7S480、D7S5 2 2、D9S162、D9S168、D9S30 4、D9S171和 D17S5 2 0 )具有统计学意义 (P<0 .0 5 ) ,然而这些位点的L OH与肿瘤病理学类型、肿瘤大小及转移性无显著相关性。此外 ,MI仅在 4例患者中出现 ,没有 1例患者符合 MI的判定标准 ,即需两个或两个以上的微卫星多态位点的异常。结论 主要发生在 D7S480、D7S5 2 2、D9S162、D9S168、D9S30 4、D9S171和 D17S5 2 0位点的 L OH可能存在与部分 SCCHN有关的潜在的肿瘤抑制基因 ,而微卫星不稳定性与

Objective To identify the frequency of loss of heterozygosity (LOH) and microsatellite instability(MI) in Chinese sample of squamous cell carcinoma of the head and neck(SCCHN). Methods 18 microsatellite markers were selected and used in the analysis of 30 paired SCCHN for LOH and MI by polymerase chain reaction. Results In 30 cases of SCCHN, LOH was identified in 12 cases (40%) with at least 1 marker. The prevalence rate of LOH was 0 to 21%, much lower than those reported for most markers. 7 out of the 18 markers (D7S480, D7S522, D9S162, D9S168, D9S304, D9S171 and D17S520 ) were identified as significant ( P <0.05). However there was no statistically significant correlation between the LOH at these loci and the clinical parameters such as pathological types, tumor size and lymph node metastasis. MI occurred in only 4 patients, but no MI could be observed using the common criteria for defining MI in two or more markers. Conclusion The most common LOH at D7S480, D7S522, D9S162, D9S168, D9S304, D9S171 and D17S520 might imply the existence of potential tumor suppressor gene of a subset of SCCHN, while MI might not be a crucial event.