口腔鳞癌中染色体9p杂合性丢失的研究

Allele-specific Chromosome 9p Deletion in Oral Cancer

目的 :探讨口腔鳞状细胞癌中 9号染色体短臂等位基因的杂合性丢失和微卫星不稳定与口腔鳞状细胞癌发生、发展之间的关系。方法 :采用PCR法检测 2 4例口腔鳞状细胞癌中染色体 9p上 8个微卫星多态位点。结果 :在2 4例口腔鳞状细胞癌中 ,10例 (41 6 7% )鳞癌组织至少有一个微卫星位点发生杂合性丢失。其主要发生在染色体9p2 1的D9S171(2 1 0 5 % )和D9S30 4(10 .0 0 % ) ,以及 9p2 2_2 3的D9S16 8(2 2 2 2 % )和D9S16 2 (15 38% )。然而 ,这些基因位点的杂合性丢失与肿瘤病理学类型、肿瘤的大小及转移性在统计学上无显著相关性 (P >0 0 5 )。此外 ,微卫星不稳定仅在 2例患者中出现 ,没有 1例患者符合微卫星不稳定的判定标准 ,即两个或两个以上的微卫星多态位点的异常。结论 :本研究中发现的口腔鳞状细胞癌在染色体 9p2 1_2 3区域发生高频率的杂合性丢失 ,提示在 9p2 1_2 3区域可能存在多个与部分口腔鳞状细胞癌相关的肿瘤抑制基因 。

Objective:The aim of this study was to investigate the relationship between loss of heterozygosity (LOH) on chromosome 9p and the pathogenesis of oral squamous cell carcinoma (OSCC). Methods: A total of 24 human OSCC specimens were analyzed for LOH on chromosome 9p using 8 microsatellite markers by means of polymerase chain reaction. Results: In 24 cases of OSCC, LOH on chromosome 9p was identified in 10 of 24 cases (41 67%) with at least one marker. The main LOH were found on 9p21 at locus D9S171 (21 05%) and D9S304 (10.00%). There were also a deletion on 9p22_23 at locus D9S168 (22 22%) and D9S162 (15 38%). However, there was no statistically significant correlation between LOH at these loci with such clinical parameters as pathological types, tumor size and lymph_node metastasis. Microsatellite instability (MSI) is rare for any of the 8 markers in 24 OSCC, No MSI could observed using the common criteria for defining MSI_its detection in two or more markers. Conclusion: We found that high frequency of LOH occurred at 9p21_23 band. Their results indicate that more than one tumor suppressor genes at chromosome 9p21_23 region related to a subset of OSCC, while MSI might not be a crucial event.\;