Clonality of Large Regenerative Nodule Accompanied by Hepatocellular Carcinoma

ABSTRACT

In order to clarify the preneoplastic nature of large regenerative nodules without dysplastic change, we analysed the clonality of hepatocellular carcinomas (HCCs) and large nodules, diameter > or =0.5 cm, of cirrhotic liver by X-linked human androgen receptor (HUMARA) gene assay, using the principle of random X chromosome methylation and inactivation in female. Ten cases of HCC and 5 cases of large nodules without dysplasia from 9 female patients were selected. All the tumors, large nodules and paired normal control cells were selectively microdissected from deparaffinized hematoxylin and eosin stained slides. Genomic DNA was isolated and digested with HhaI. Polymerase chain reaction(PCR) amplication of the HUMARA locus was performed using 32P-a-dCTP containing PCR mixtures. The PCR amplified products were separated by gel electrophoresis and analysed by autoradiography. Nine HCCs from 8 patients were monoclonal and 1 case was polyclonal and the remaining 1 case was not polymorphic at the HUMARA locus. The HCC case which showed polyclonality contained many inflammatory cells. All the large nodules were polyclonal by HUMARA assay. These results suggest that all or most of the cells composing the large regenerative nodules without dysplasia are polyclonal. This assay may be informative for the differentiation between regenerative and preneoplastic nodules in cirrhotic liver and the size of nodule may be not important in hepatocarcinogenesis.