人端粒酶逆转录酶（hTERT）信使核糖核酸（mRNA）表达与人乳腺癌中的端粒酶活性相关。

hTERT mRNA expression correlates with telomerase activity in human breast cancer.

作者信息

Kirkpatrick K L, Clark G, Ghilchick M, Newbold R F, Mokbel K

机构信息

Academic Division of Breast Surgery, St George's Hospital, University of London, UK.

出版信息

Eur J Surg Oncol. 2003 May;29(4):321-6. doi: 10.1053/ejso.2002.1374.

DOI:10.1053/ejso.2002.1374

PMID:12711283

Abstract

AIMS

Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal length and stability thus leading to cellular immortalisation. hTERT (human telomerase reverse transcriptase) gene seems to be the rate-limiting determinant of telomerase reactivation. hTERT mRNA expression was reported to correlate with telomerase activity in cell lines and some human tumours. However the correlation between telomerase activity and hTERT mRNA expression has not been previously examined in human breast cancer. The present study aims to quantitatively measure the expression of hTERT mRNA and telomerase activity in human breast cancer and examine the relationship between these parameters. Furthermore the associations with other parameters including estrogen receptor (ER) and progesterone receptor (PgR) status, DNA ploidy, and S-phase fraction (SPF) are also examined.

METHODS

RNA was extracted from 18 breast carcinomas and hTERT mRNA expressions were estimated by reverse transcriptase-PCR (RT-PCR) and Taqman methodology. These tumours had already been analysed for ER and PgR status using ligand-binding assays and had had their DNA ploidy and S-phase fractions measured by flow cytometry. Telomerase activity had already been determined by using a modified telomeric repeat and amplification protocol (TRAP) assay.

RESULTS

The expression of hTERT mRNA in the breast tumours ranged between 1.3 and 2.7 x 10(7) copy numbers per micro g of cellular RNA (the median value was 2.7x10(5) and the mean was 3.1 x 10(6)). Telomerase activity was between 0 and 246 units of Total Protein Generated (TPG), where one unit of TPG was equal to 600 molecules, of telomerase substrate primers extended by at least three telomeric repeats. The median level of TPG was 60 units and the mean level was 81 units). Telomerase activity was found to significantly correlate with hTERT expression (r(s)=0.51112, P=0.0302). There was no significant correlation between hTERT and other parameters.

CONCLUSION

hTERT mRNA expression significantly correlates with telomerase activity in human breast cancer. This is consistent with the hypothesis that hTERT is the catalytic and rate-limiting determinant subunit of the enzyme.

摘要

目的

端粒酶是一种核糖核蛋白酶，在细胞分裂后合成端粒，维持染色体长度和稳定性，从而导致细胞永生化。人端粒酶逆转录酶（hTERT）基因似乎是端粒酶重新激活的限速决定因素。据报道，hTERT mRNA表达与细胞系和一些人类肿瘤中的端粒酶活性相关。然而，此前尚未在人类乳腺癌中研究端粒酶活性与hTERT mRNA表达之间的相关性。本研究旨在定量测量人类乳腺癌中hTERT mRNA的表达和端粒酶活性，并研究这些参数之间的关系。此外，还研究了与其他参数的关联，包括雌激素受体（ER）和孕激素受体（PgR）状态、DNA倍性和S期分数（SPF）。

方法

从18例乳腺癌中提取RNA，通过逆转录聚合酶链反应（RT-PCR）和Taqman方法估计hTERT mRNA表达。这些肿瘤已经使用配体结合试验分析了ER和PgR状态，并通过流式细胞术测量了DNA倍性和S期分数。端粒酶活性已经通过使用改良的端粒重复序列扩增协议（TRAP）测定法确定。

结果

乳腺肿瘤中hTERT mRNA的表达范围为每微克细胞RNA 1.3至2.7×10（7）拷贝数（中位数为2.7×10（5），平均值为3.1×10（6））。端粒酶活性在0至246个总蛋白生成单位（TPG）之间，其中1个TPG单位等于600个分子，即至少延伸三个端粒重复序列的端粒酶底物引物。TPG的中位数水平为60单位，平均水平为81单位）。发现端粒酶活性与hTERT表达显著相关（r（s）=0.51112，P=0.0302）。hTERT与其他参数之间无显著相关性。