Related Experiment Videos
Telomerase and c-myc expression in hepatocellular carcinomas
Yao-Chi Liu1, Cheng-Jueng Chen, Hurng-Sheng Wu
1Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC. yaochiliu@yahoo.com.tw
Summary
Human telomerase reverse transcriptase (hTERT) expression correlates with telomerase activity in hepatocellular carcinoma (HCC). However, c-myc does not significantly regulate hTERT in HCC, suggesting alternative regulatory pathways.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Telomerase is frequently activated in cancers, including hepatocellular carcinoma (HCC).
- The human telomerase reverse transcriptase (hTERT) gene promoter contains c-myc binding sites, suggesting a role in hTERT transcriptional activation.
- The specific roles of hTERT and its relationship with c-myc in HCC tumorigenesis remain understudied.
Purpose of the Study:
- To investigate the expression of hTERT mRNA in HCC tissues using in situ hybridization.
- To determine the correlation between hTERT expression, telomerase activity, and c-myc levels in HCC.
- To analyze the hTERT promoter for mutations and assess the relationship between hTERT, c-myc, and HCC differentiation.
Main Methods:
- Telomerase activity was measured using the TRAP assay in 23 HCC specimens.
- hTERT mRNA expression was detected via in situ hybridization in 57 HCC specimens.
- Immunohistochemistry for c-myc, DNA sequencing of the hTERT promoter, and analysis of tumor differentiation were performed on 57 HCC specimens.
Main Results:
- hTERT mRNA was detected in 82.5% of HCC specimens, paralleling telomerase activity.
- hTERT mRNA regulation was not significantly associated with c-myc levels (P<0.954).
- Mutations in the hTERT promoter (nucleotide transitions/transversions) were observed in 17 HCC cases; neither hTERT expression nor c-myc levels correlated with HCC differentiation.
Conclusions:
- hTERT expression is linked to telomerase activity in HCC.
- Telomerase activity in HCC is not solely regulated by c-myc, indicating the involvement of other pathways.
- The absence of telomerase activity in some HCC cases suggests alternative telomere maintenance mechanisms, and neither telomerase activity nor c-myc significantly impacts HCC differentiation.