AIM To study the abnormal expression of β-catenin geneand its relationship with invasiveness of primaryhepatocellular carcinoma among Chinese people.METHODS Thirty-four hepatocellular carcinoma(HCC)specimens and adjacent para-cancerous tissues,4 normalliver tissues were immunohistochemically stained to studysubcellular distribution of β-catenin.Semiquantitiveanalysis of expression of β-catenin gene exon 3 mRNA wasexamined by RT-PCR and in situ hybridization.Therelationship between expressions of both β-cateninprotein,mRNA and clinicopathological characteristics ofHCC was also analyzed.RFSULTS Immunohistochemistry showed that all normalliver tissues and para-cancerous tissues examineddisplayed membranous type staining for β-catenin protein,occasionally with weak expression in the cytoplasm,While 21 cases(61.8%)of HCC examined showedaccumulated type in cytoplasms or nuclei.The accumuledtype Labling Index(LI)of cancer tissue and para-cancarous tissue was(59.9 ± 26.3)and(18.3 ± 9.7)respectively (P<0.01).Higher accumulated type LI wasclosely related with invasiveness of HCC.Results of RT-PCR showed the β-catenin gene exon 3 mRNA ExpressionIndex(El)of 34 HCCs was higher than that of para-cancerous tissue and normal liver tissue.Using in situhybridization,the signal corresponding to β-catenin geneexon 3 mRNA was particularly strong in cytoplasm of HCCwhen compared with those of para-cancerous and normalliver tissues.Over expression of β-catenin exon 3 wasalso found to be correlated with high metastatic potentialof HCC.CONCLUSION Abnormal expression of β-catenin genemay contribute importantly to the invasiveness of HCCamong Chinese people. AIM To study the abnormal expression of β-catenin gene and its relationship with invasiveness of primary hepatocellular carcinoma among Chinese people.METHODS Thirty-four hepatocellular carcinoma (HCC) specimens and adjacent para-cancerous tissues,4 normalliver tissues were immunohistochemically stained to studysubcellular distribution of β -catenin.Semiquantitiveanalysis of expression of expression of β-catenin gene exon 3 mRNA wasexamined by RT-PCR and in situ hybridization.Therelationship between expressions of both ofβ-cateninprotein,mRNA and clinicopathologicalcharacteristic ofHCC was also analyzed.RFSULTS Immunohistoologydisplay that all normalliver tissues and Para-cancerous tissues examineddisplay membranous type staining for β-catenin protein, occasionally with weak expression in the cytoplasm,While 21 cases(61.8%) of HCC covered receivedaccumulated type in cytoplasms or nuclei.The accumuledtype Labling Index(LI)of cancer tissue and Para-cancarous tissue was (59.9 ± 26.3) and (18.3 ± 9.7) (P<0.01).Higher accumulated type LI wasclosely related with invasiveness of HCC.Results of RT-PCR showed the β-catenin gene exon 3 mRNA ExpressionIndex(El) of 34 HCCs was higher than that of para-cancerous tissue and normal In liver tissue.Using in situ hybridization, the signal corresponding to β-catenin geneexon 3 mRNA was strongly strong in cytoplasm of HCCwhen compared with those of para-cancerous and normal liver tissues. Over expression of β-catenin exon 3 was also found to be correlated with high Metastatic potentialof HCC.CONCLUSION Abnormal expression of β-catenin genemay contribute importantly to the invasiveness of HCCamong Chinese people.