title: Pro-apoptotic and anti-proliferative effects of 3,3'-diindolylmethane in nasopharyngeal carcinoma cells via downregulation of telomerase activity.
abstract: 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.
authors.affiliation: Research Institute of Otolaryngology‑Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
authors.forename: Fen
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Otolaryngology‑Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Research Institute of Otolaryngology‑Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Otolaryngology‑Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
authors.forename: Shi-Ming
authors.initials: SM
authors.lastname: Chen
authors.affiliation: Research Institute of Otolaryngology‑Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
authors.forename: Bo-Kui
authors.initials: BK
authors.lastname: Xiao
authors.affiliation: Research Institute of Otolaryngology‑Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
authors.forename: Ze-Zhang
authors.initials: ZZ
authors.lastname: Tao
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D015536:Down-Regulation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy*; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism; D059505:Telomere Homeostasis / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D019098:Telomerase; C016392:3,3'-diindolylmethane