Overexpression of c-myc gene without gene amplification in human hepatocellular carcinoma

Objective. To clarify the relationship between c-myc gene amplification and expression in human hepatocellular carcinoma (HCC) tissue. Methods. Levels of amplification, transcription and P62 myc expression of c-myc gene in tumor tissues and corresponding non-tumor tissues were systematically studied using Dot blot hybridization, in situ hybridization and immunohistochemical technique, respectively. The 14 pairs of specimens were resected from patients with HCC. Results. The amplification of c-myc gene was not found in tumor and non-tumor tissues. Overexpression of c-myc mRNA transcription was detected in 11 tumor tissues and 10 non-tumor tissues. The positive rate of P62 myc was 85.7% (12/14) in tumor tissues and 92.9% (13/14) in non-tumor tissues, respectively. A close correlation was noticed between c-myc mRNA and P62 myc expression. The results suggested that c-myc gene overexpression was not related to its amplification. Conclusion. The overexpression of c-myc mRNA and gene product without amplification may be characteristic in HCC.