Tags

Type your tag names separated by a space and hit enter

Telomerase and c-myc expression in hepatocellular carcinomas.
Eur J Surg Oncol. 2004 May; 30(4):384-90.EJ

Abstract

BACKGROUND

Telomerase is activated in the majority of cancer tissues and immortalized cell lines. The hTERT (human telomerase reverse transcriptase-major component of telomerase) gene promoter has been cloned and contains many c-myc binding sites that mediate hTERT transcriptional activation. Thus far, the role of hTERT in tumorigenesis in hepatocellular carcinoma (HCC) has been little studied using RNA in situ hybridization. The relationship between c-myc and telomerase in human HCC tissue is undetermined.

MATERIALS AND METHODS

The telomerase activity was assayed using TRAP in specimens from 23 HCC patients, hTERTmRNA was detected using in situ hybridization from 57 HCC patients. The immunohistochemistry for c-myc and DNA sequence for hTERT promoter, and tumour differentiation in relation to hTERT and c-myc expression were determined in 57 specimens.

RESULT

hTERTmRNA was found in 47/57 (82.5%) HCC specimens using in situ hybridization. The hTERT expression paralleled telomerase activity, but hTERTmRNA regulation was not significantly associated with c-myc level (P<0.954) The DNA sequence analysis of the hTERT promoter in specimens from 17 HCC revealed 15 cases of nucleotide transition (T-->C) over 5'-end of distal E-box and one case of nucleotide transversion (G-->C) over 5'-end of proximal E-box. Neither the hTERT expression (P< 0.890) nor c-myc level (P < 0.348) were related to HCC differentiation.

CONCLUSIONS

The hTERT expression paralleled telomerase activity. The telomerase activity in HCC was not only regulated by c-myc. Another pathways might contribute to hTERT and telomerase activity regulation. The lack of telomerase activity in specimens from 17.4% of HCC cases might indicate an alternative pathway for maintaining telomere length. Furthermore, both the telomerase activity and c-myc had no significant role in HCC differentiation.

Authors+Show Affiliations

Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC. yaochiliu@yahoo.com.twNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15063891

Citation

Liu, Yao-Chi, et al. "Telomerase and C-myc Expression in Hepatocellular Carcinomas." European Journal of Surgical Oncology : the Journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology, vol. 30, no. 4, 2004, pp. 384-90.
Liu YC, Chen CJ, Wu HS, et al. Telomerase and c-myc expression in hepatocellular carcinomas. Eur J Surg Oncol. 2004;30(4):384-90.
Liu, Y. C., Chen, C. J., Wu, H. S., Chan, D. C., Yu, J. C., Yang, A. H., Cheng, Y. L., Lee, S. C., & Harn, H. J. (2004). Telomerase and c-myc expression in hepatocellular carcinomas. European Journal of Surgical Oncology : the Journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology, 30(4), 384-90.
Liu YC, et al. Telomerase and C-myc Expression in Hepatocellular Carcinomas. Eur J Surg Oncol. 2004;30(4):384-90. PubMed PMID: 15063891.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Telomerase and c-myc expression in hepatocellular carcinomas. AU - Liu,Yao-Chi, AU - Chen,Cheng-Jueng, AU - Wu,Hurng-Sheng, AU - Chan,De-Chuan, AU - Yu,Jyh-Cherng, AU - Yang,An-Hang, AU - Cheng,Yueng-Leung, AU - Lee,Shih-Chun, AU - Harn,Horng-Jyh, PY - 2004/01/07/accepted PY - 2004/4/6/pubmed PY - 2004/7/16/medline PY - 2004/4/6/entrez SP - 384 EP - 90 JF - European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology JO - Eur J Surg Oncol VL - 30 IS - 4 N2 - BACKGROUND: Telomerase is activated in the majority of cancer tissues and immortalized cell lines. The hTERT (human telomerase reverse transcriptase-major component of telomerase) gene promoter has been cloned and contains many c-myc binding sites that mediate hTERT transcriptional activation. Thus far, the role of hTERT in tumorigenesis in hepatocellular carcinoma (HCC) has been little studied using RNA in situ hybridization. The relationship between c-myc and telomerase in human HCC tissue is undetermined. MATERIALS AND METHODS: The telomerase activity was assayed using TRAP in specimens from 23 HCC patients, hTERTmRNA was detected using in situ hybridization from 57 HCC patients. The immunohistochemistry for c-myc and DNA sequence for hTERT promoter, and tumour differentiation in relation to hTERT and c-myc expression were determined in 57 specimens. RESULT: hTERTmRNA was found in 47/57 (82.5%) HCC specimens using in situ hybridization. The hTERT expression paralleled telomerase activity, but hTERTmRNA regulation was not significantly associated with c-myc level (P<0.954) The DNA sequence analysis of the hTERT promoter in specimens from 17 HCC revealed 15 cases of nucleotide transition (T-->C) over 5'-end of distal E-box and one case of nucleotide transversion (G-->C) over 5'-end of proximal E-box. Neither the hTERT expression (P< 0.890) nor c-myc level (P < 0.348) were related to HCC differentiation. CONCLUSIONS: The hTERT expression paralleled telomerase activity. The telomerase activity in HCC was not only regulated by c-myc. Another pathways might contribute to hTERT and telomerase activity regulation. The lack of telomerase activity in specimens from 17.4% of HCC cases might indicate an alternative pathway for maintaining telomere length. Furthermore, both the telomerase activity and c-myc had no significant role in HCC differentiation. SN - 0748-7983 UR - https://www.unboundmedicine.com/medline/citation/15063891/Telomerase_and_c_myc_expression_in_hepatocellular_carcinomas_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0748798304000046 DB - PRIME DP - Unbound Medicine ER -