{"paper_id":"5730f77b-fac7-4e62-bd68-8284b08f64f1","body_text":"Print ISSN: 1019-6439\nOnline ISSN: 1791-2423\nInternational Journal of Molecular Medicine is an international journal devoted to molecular mechanisms of human disease.\nInternational Journal of Oncology is an international journal devoted to oncology research and cancer treatment.\nCovers molecular medicine topics such as pharmacology, pathology, genetics, neuroscience, infectious diseases, molecular cardiology, and molecular surgery.\nOncology Reports is an international journal devoted to fundamental and applied research in Oncology.\nExperimental and Therapeutic Medicine is an international journal devoted to laboratory and clinical medicine.\nOncology Letters is an international journal devoted to Experimental and Clinical Oncology.\nExplores a wide range of biological and medical fields, including pharmacology, genetics, microbiology, neuroscience, and molecular cardiology.\nInternational journal addressing all aspects of oncology research, from tumorigenesis and oncogenes to chemotherapy and metastasis.\nMultidisciplinary open-access journal spanning biochemistry, genetics, neuroscience, environmental health, and synthetic biology.\nOpen-access journal combining biochemistry, pharmacology, immunology, and genetics to advance health through functional nutrition.\nPublishes open-access research on using epigenetics to advance understanding and treatment of human disease.\nAn International Open Access Journal Devoted to General Medicine.\nArticle\n- Authors:\n-\nPages: 43-51|Published online on: January 1, 2006https://doi.org/10.3892/ijo.28.1.43\n- Expand metrics +\nTelomerase activation, known to be stimulated by estrogen, is essential for cellular immortalization and trans-formation, both of which play a role in tumorigenesis. Dioxin and dioxin-like compounds have been shown to induce endometriosis and promote estrogen-dependent tumors. In this study, we show that either 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or a combination of TCDD and 17-β estradiol (E2) increase telomerase activity and the expression of the human telomerase catalytic subunit (hTERT) in human choriocarcinoma (BeWo) cells. Compared with estrogen or TCDD alone, the combination treatment did not show an additive effect. Likewise, treatment with either E2 or TCDD increased DNA synthesis and the cell population in S-phase, as detected by FACS analysis. However, following treatment with the E2 and TCDD combination, the proportion of cells in S-phase was actually lower than in cells treated with TCDD alone. These results suggest that TCDD alone mimics estrogenic action in telomerase activation and cell proliferation but, in the presence of estrogen, TCDD-induced actions were partially counteracted. E2 and TCDD also induced c-Myc, which is a transcriptional activator of hTERT in Bewo, but neither of these agents induced telomerase activity in HO15.19 c-myc-null cells. In contrast, only TCDD upregulated telomerase in TGR-1 cells, which are c-Myc expressing but lacking ER expression. The findings suggest that TCDD induces telomerase activity mediated through AhR signaling and/or ER-independent c-Myc signaling. The present study provides insight into the mechanism of promoter activity of TCDD in estrogen-related tumors.\nCopy and paste a formatted citation\nSpandidos Publications style\nSarkar P, Shiizaki K, Yonemoto J and Sone H: Activation of telomerase in BeWo cells by estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin in co-operation with c-Myc. Int J Oncol 28: 43-51, 2006.\nAPA\nSarkar, P., Shiizaki, K., Yonemoto, J., & Sone, H. (2006). Activation of telomerase in BeWo cells by estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin in co-operation with c-Myc. International Journal of Oncology, 28, 43-51. https://doi.org/10.3892/ijo.28.1.43\nMLA\nSarkar, P., Shiizaki, K., Yonemoto, J., Sone, H.\"Activation of telomerase in BeWo cells by estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin in co-operation with c-Myc\". International Journal of Oncology 28.1 (2006): 43-51.\nChicago\nSarkar, P., Shiizaki, K., Yonemoto, J., Sone, H.\"Activation of telomerase in BeWo cells by estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin in co-operation with c-Myc\". International Journal of Oncology 28, no. 1 (2006): 43-51. https://doi.org/10.3892/ijo.28.1.43","source_license":"public-domain-us","license_restricted":false}