Open AccessGene Expression for Suppressors of Telomerase Activity (Telomeric‐repeat Binding Factors) in Breast Cancer
Author(s) -
Saito Kaori,
Yagihashi Atsuhito,
Nasu Shunichi,
Izawa Yoko,
Nakamura Masashi,
Kobayashi Daisuke,
Tsuji Naoki,
Watanabe Naoki
Publication year - 2002
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.2002.tb02166.x
Subject(s) - telomerase , telomere , breast cancer , biology , cancer , gene , cancer research , gene expression , microbiology and biotechnology , telomerase reverse transcriptase , restriction fragment , genetics
Mechanisms regulating telomerase activity and telomere length remain incompletely understood in human breast cancer. We therefore studied gene expression for telomeric‐repeat binding factors (TRFs) in relation to telomerase activity, telomere length, and clinicopathologic factors in human breast cancer. Telomerase activity was detected in 65.8% of 38 breast cancers, but none of 16 non‐cancerous samples. Terminal restriction fragments were longer in noncancerous than in cancerous tissues, but not significantly. Among 8 patients with both cancer and paired noncancerous tissue available for terminal restriction fragments length assay, terminal restriction fragments were shorter in cancers than in paired noncancerous samples in all but one. Significantly more mRNA encoding TRF1 and 2 was detected in noncancerous than in cancer tissues. Additionally, expression of TRF1 and 2 mRNA was significantly higher in cancers without detectable telomerase activity than in cancers showing activity. Expression of these genes tended to show a negative correlation with terminal restriction fragments length, but this was not statistically significant. No correlation was seen between TRF1 or 2 mRNA expression, and clinicopathologic factors except for TRF1 with respect to tumor size and progesterone receptor status. In addition to reactivation of telomerase activity, escape from negative regulation of this activity is needed to maintain telomere length during cell proliferation in breast cancer. Genes encoding telomerase inhibitors might be of value in gene therapy against human breast cancer.