Pro-apoptotic and anti-proliferative effects of 3,3′-diindolylmethane in nasopharyngeal carcinoma cells via downregulation of telomerase activity

• Published in: Molecular medicine reports Vol. 12; no. 3; pp. 3815 - 3820
• Main Authors: LI, FEN, XU, YONG, CHEN, CHEN, CHEN, SHI-MING, XIAO, BO-KUI, TAO, ZE-ZHANG
• Format: Journal Article
• Language: English
• Published: Greece D.A. Spandidos 01.09.2015; Spandidos Publications; Spandidos Publications UK Ltd
• Subjects: 3,3′-diindolylmethane; Androgen receptors; anti-proliferative; Antineoplastic Agents - pharmacology; Apoptosis; Apoptosis - drug effects; Biotechnology; Cell cycle; Cell division; Cell growth; Cell Line, Tumor; Cell proliferation; Cell Proliferation - drug effects; Chemotherapy; Down-Regulation - drug effects; Drug Screening Assays, Antitumor; Drug therapy; Flow cytometry; Gene expression; Genetic aspects; Health aspects; human telomerase reverse transcriptase; Humans; Indoles - pharmacology; Medicine, Botanic; Medicine, Herbal; Nasopharyngeal cancer; Nasopharyngeal carcinoma; Nasopharyngeal Neoplasms - drug therapy; Physiological aspects; Polymerase chain reaction; pro-apoptosis; Protein expression; Proteins; Radiation therapy; Reverse transcription; RNA-directed DNA polymerase; Rodents; Studies; Telomerase; Telomerase - genetics; Telomerase - metabolism; Telomerase reverse transcriptase; Telomere Homeostasis - drug effects; Telomeres; Throat cancer; China; United States > US
• ISSN: 1791-2997; 1791-3004
• DOI: 10.3892/mmr.2015.3836

The pro-apoptotic and anti-proliferative effects of 3,3′-diindolylmethane (DIM) in various tumor cell types have been widely investigated. The underlying mechanisms were suggested to include cell cycle arrest, cell signaling inhibition and downregulation of the androgen receptor. The present study demonstrated that DIM induced apoptosis and inhibited proliferation in nasopharyngeal carcinoma cells by downregulating the activity of telomerase. The nasopharyngeal carcinoma cell line 5-8F was selected for this purpose. A cell counting kit-8 assay and flow cytometry were performed to detect apoptosis and proliferation of 5-8F cells, respectively, which revealed the pro-apoptotic and anti-proliferative effects of DIM. Telomerase activity was detected using a telomeric repeat amplification protocol assay, which revealed that the telomerase activity was inhibited by DIM in a dose-dependent manner. Reverse transcription polymerase chain reaction was used to detect the mRNA expression levels of human telomerase reverse transcriptase (hTERT) and human telomerase RNA (hTR), and western blot analysis was used to detect the protein expression of hTERT. The results showed that the mRNA and protein expression of hTERT were downregulated in 5-8F cells following treatment with DIM; however, the mRNA expression of hTR remained unchanged, suggesting that hTERT was the target of DIM. To further identify the target, the length of telomeres was continually measured using a telomere length detection kit, revealing that the telomeres were shortened by DIM in an concentration-dependent manner. The present study confirmed that DIM had pro-apoptotic and anti-proliferative effects in nasopharyngeal carcinoma cells by regulating telomerase.