• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1633-1636
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• 2008

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.89-95
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• 2002

Telomerase is a ribonucleoprotein complex, whose function is to add telomeric repeats $(TTAGGG)_n$ to chromosomal ends and is also known to play an important role in cellular immortalization. Telomerase is highly active in most tumor cells, yet not in normal cells. Therefore, it may have possible applications in cancer gene therapy. Telomerase consists of two essential components; a telomerase RNA template (hTR) and a catalytic subunit (hTERT). The current study attempted to inhibit the "open" part of the human telomerase RNA (hTR) with an antisense sequence-expressing adenovirus. It was found that the antisense telomerase adenovirus suppressed the telomerase activity, tumor cell growth, and survival in vitro. Furthermore, FACS analysis and TUNEL assay suggested that the reduce viability was mediated through the induction of apoptosis, indicating that this approach might be a useful method for suppressing cancer growth in targeted cancer gene therapy.

• Journal of Life Science
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• v.18 no.6
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• pp.884-890
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• 2008

Genistein, an isoflavone in soybean products, is a potential chemopreventive agent against various types of cancer. There are several studies documenting molecular alterations leading to cell cycle arrest at G2/M phase and induction of apoptosis; however, its mechanism of action and its molecular targets on the prostaglandin $E_2$ ($PGE_2$) production and telomere length regulation in human cancer remain unclear. In this study, we investigated the effect of genistein on the levels of cyclooxygenases (COXs) and telomere regulatory components of several human cancer cell lines (T24, human bladder carcinoma cells; U937, human leukemic cells; AGS, human stomach adenocarcinoma cells and SK-MEL-2, human skin melanoma cells). Genistein treatment resulted in the inhibition of cancer cell proliferation in a concentration-dependent manner. It was found that genistein treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in $PGE_2$ synthesis. Genistein treatment also partly inhibited the levels of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR) and telomerase-associated protein (TEP)-1, and the activity of telomerase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of genistein.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.517-521
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• 2003

Telomerase is a ribonucleoprotein complex whose function is to add telomeric repeats to chromosomal ends. Telomerase consists of two essential components, telomerase RNA template (hTR) and catalytic subunit (hTERT). hTERT is expressed only in cells and tissues positive for telomerase activity, i.e., tumor and fetal cells. In this report, the possibility of utilization of the hTERT promoter in targeted cancer gene therapy was tested. The hTERT promoter was cloned in the replacement of the CMV promoter, and the HSV-TK gene was subcloned to be controlled by the hTERT gene promoter in the adenovirus shuttle plasmid. Then, the recombinant adenovirus Ad-hT-TK was constructed and was infected into normal and human gynecological cancer cell lines. The selective tumor specific cell death by Ad-hT-TK was identified through these experiments, showing that Ad-hT-TK could be used for targeted cancer gene therapy.

• Journal of Life Science
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• v.19 no.4
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• pp.502-507
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• 2009

In modern oriental medicine, bee venom therapy is being used for aqua-acupuncture to relieve pain and to cure inflammatory diseases such as rheumatoid arthritis, osteoarthritis, and gout. Bee venom therapy has been processed and reported in many experimental studies, with regard to its effects on pain alleviation, anti-inflammation, removal of fever, anti-convulsion, suppression of tumor and immunity strengthening, etc., however, its mechanism of action, molecular targeting on prostaglandin $E_2$ ($PGE_2$) production and telomere length regulation in human cancer remains unclear. In this study, we investigated the effect of bee venom on the levels of cyclooxygenases (COXs) and telomere regulatory components of A549 human lung cancer cells. Bee venom-induced anti-proliferative effects of A549 cells were associated with the inhibition of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR), transcription factor c-myc and the activity of telomerase. In addition, bee venom treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in $PGE_2$ synthesis. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of bee venom.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.546.2-546
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• 2003

Dental follicle is the mesenchymal tissue which surrounds developing tooth germ. During tooth root development, periodontal components such as cementum, periodontal ligament and alveolar bone are considered to be created by progenitors present in the dental follicle. However, little is known about these progenitors. Previously we observed that cultured bovine dental follicle cells (BDFC) contained putative cementoblast progenitors. To further analyze the biology of these cells, we have attempted to immortalize BDFC by expression of the polycomb group protein Bmi-1 and human telomerase reverse transcriptase (hTERT). The BDFC expressing Bmi-1 and hTERT showed extended life span by 90 population doublings more than normal BDFC, and still contained cells with potential to differentiate into cementoblasts upon implantation into immunodeficiency mice. Among them, we established a clonal cell line designated as BCPb8, which formed cemetum-like mineralized tissue reactive to anti-cementum specific monoclonal antibody, 3G9, and expressed mRNA for bone sialoprotein, osteocalcin, osteopontin and type I collagen upon implantation. Thus with the combination of hTERT and Bmi-1, we succeeded in immortalization of cementoblast progenitor in BDFC without affecting differentiation potential. The BCPb8 progenitor cell line could be a useful tool not only to study cementogenesis but also to develop regeneration therapy for periodontitis.