摘要： 目的·研究口腔白斑（oral leukoplakia，OL）患者病损发生发展中的DNA损伤修复基因表达谱，并验证关键基因共济失调毛细血管扩张症突变基因（ataxia-telangiectasia mutated，
ATM）和组蛋白2A变异体家族成员X（histone variant H2A family member X，
H2AX）的mRNA和蛋白表达。方法·利用Affymetrix HTA 2.0芯片对口腔正常黏膜（
n=3）、低危白斑（
n=4）、高危白斑（
n=4）、早期鳞状细胞癌（鳞癌，
n=6）进行转录组学的高通量检测，利用基因本体数据库（Gene Ontology，GO）富集分析筛选出生物学功能为DNA损伤修复的相关基因［差异倍数（fold change，FC）对数的绝对值（|log
2FC|）≥2.0且
P<0.05］，利用实时定量PCR（real-time quantitative PCR，qPCR）和蛋白质印迹法分别对人正常口腔黏膜角化细胞（HOK）、白斑细胞系（Leuk1）和鳞癌细胞系（HN13）中的关键基因
ATM和
H2AX进行mRNA和蛋白表达验证。结果·DNA损伤修复基因在白斑发生发展中存在异常表达，从正常黏膜发展到低危白斑有7个|log
2FC|≥2.0的基因，从低危白斑发展到高危白斑有7个|log
2FC|≥2.0的基因，从高危白斑发展到鳞癌有52个|log
2FC|≥2.0的基因。qPCR对关键基因验证结果显示，
ATM和
H2AX基因在HOK细胞、Leuk1细胞和HN13细胞中的表达量均呈阶梯式升高（
P<0.05）。蛋白质印迹法结果显示，磷酸化H2AX（γ-H2AX）蛋白在HOK细胞、Leuk1细胞和HN13细胞中亦逐步上调（
P<0.05）。ATM蛋白在Leuk1细胞中的表达比在HOK细胞中表达明显增强（
P<0.05），但在HN13细胞中的表达明显降低（
P<0.05）。结论·DNA损伤修复基因
ATM和
H2AX参与OL的发生发展。
关键词: 口腔白斑, 鳞状细胞癌, DNA损伤修复, 共济失调毛细血管扩张症突变基因, 组蛋白2A变异体家族成员X Abstract: Objective·To study the gene expression profile of DNA damage repair in the occurrence and development of oral leukoplakia (OL) and to verify the expression of mRNA and protein of key genes, ataxia-telangiectasia mutated (ATM) and histone variant H2A family member X (H2AX).
Methods·Affymetrix HTA 2.0 array was used to detect the high-throughput transcriptome of normal mucosa (n=3), low-risk leukoplakia (n=4), high-risk leukoplakia (n=4) and early squamous cell carcinoma (n=6). Gene Ontology function analysis was used to screen out the genes related to DNA damage repair [|log2(chang fold, FC)|≥2.0 and P<0.05]. Real-time quantitative PCR (qPCR) and Western blotting were used to verify the mRNA and protein expression of key genes (ATM and H2AX) in human normal oral mucosal keratinocytes (HOK), OL (Leuk1) and squamous cell carcinoma cell lines (HN13), respectively.
Results·DNA damage repair genes abnormally expressed in the occurrence and development of leukoplakia. There were 7 genes with |log2FC|≥2.0 from normal mucosa to low-risk leukoplakia, 7 genes with |log2FC|≥2.0 from low-risk leukoplakia to high-risk leukoplakia, and 52 genes with |log2FC|≥2.0 from high-risk leukoplakia to squamous cell carcinoma. qPCR revealed that the expression of ATM and H2AX in HOK cells, Leuk1 cells and HN13 cells increased stepwise (P<0.05). Western blotting revealed that the expression of γ-H2AX protein was also up-regulated in the HOK cells, Leuk1 cells and HN13 cells (P<0.05). ATM protein was up-regulated in Leuk1 cells compared with HOK cells, but down-regulated in HN13 cells (P<0.05).
Conclusion·DNA damage repair genes, ATM and H2AX, are involved in the occurrence and development of OL.
Key words: oral leukoplakia (OL), squamous cell carcinoma, DNA damage repair, ataxia-telangiectasia mutated (ATM), histone variant H2A family member X (H2AX) PDF全文下载地址:
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