慢性乙型肝炎和肝硬化组织中变异肝细胞结节的分子遗传学改变

Changes of molecular genetics of nodules of altered hepatocytes in chronic B hepatitis and liver cirrhosis

目的：探讨慢性乙型肝炎和肝硬化组织中变异肝细胞结节（NAH）的染色体畸变情况,从分子水平进一步证实其肿瘤性本质.方法：利用激光显微切割技术解剖10个NAH,并提取全基因组DNA,通过基于女性X染色体失活的嵌合性及磷酸苷油酸激酶（PGK）和雄激素受体（AR）基因位点多态性的克隆性分析技术,选择出单克隆性的NAH进行微阵列比较基因组杂交（array-CGH）,观察其染色体畸变情况.结果：10个NAH中只有4个为单克隆性增生,可用于进一步分析,且其中一个NAH伴有小细胞改变（SCC）.array-CGH分析结果显示,只有伴有SCC的NAH在染色体1q21.2～q25.2,19q13.12～q13.43和8q区域发现有增缢,在染色体4p和8p上有缺失,并且部分与HCC染色体畸变情况一致.而其它3个不伴有SCC的NAH无染色体畸变发生.结论：伴有SCC改变的NAH是一种真性肿瘤,是一种较晚期的癌前病变.

AIM： To investigate the structural aberration of chromosome of nodules of altered hepatocytes （ NAHs ） in chronic B hepatitis and liver cirrhosis and confirm their neoplastic nature. METHODS： We combined laser microdissection and clonal analysis based on X-chromosome inactivation mosaicism to examine all the samples. Firstly, 10 NAHs were dissected by laser microdissection. Genomic DNA from all samples were extracted, pretreated with Hpa II or Hha I, and then amplified via nested polymerase chain reaction （ PCR ） for phosphoglycerate kinase （ PGK ） and androgen receptor （AR） genes. Monoclonal lesions among them were analysed using array-comparative genomic hybridization （array-CGH）. Then we observed their chromosomal aberrations. RESULTS： Four out of 10 NAHs were demonstrated to be monoclonal lesions and informative for further analysis, and 1 out of 4 monoclonal lesions belonged to NAH with small cell change （SCC）. Array-CGH analysis revealed changes in DNA copy number in 4 chromosomal regions in one NAH with SCC. The frequent DNA copy number increases were detected at lq21.2 -q25.2,19 q13.12 - q13.43, 8q and decreases were detected at 4p and 8p. Moreover, a part of chromosomal aberrations was coincided with that of HCC. However, there were no chromosomal aberrations in another 3 NAHs without SCC. CONCLUSION： NAH with SCC is a true neoplasm, a late event during NAH progression, a premalignant morphologic phenotype. There is chromosomal aberration in them, which may provide a scientific basis for further screening the related genes of early HCC.