The Telomerase and Alternative Lengthening of Telomeres Mechanisms Regulate Laryngeal Cancer Cell Apoptosis via the PI3K/Akt Pathway

<b><i>Purpose:</i></b> To investigate the possible telomerase and alternative lengthening of telomeres (ALT) mechanisms influencing the apoptosis of laryngeal squamous cells. <b><i>Materials and Methods:</i></b> The effects of the telomerase mechanism were observed by knockdown of human telomerase reverse transcriptase (hTERT). The ALT mechanism was induced by silencing related genes including <i>TRF2</i>, <i>RAD51</i>, and <i>NBS1</i>. Effects of telomerase and ALT mechanisms on tumor development were confirmed by xenograft tumors model. Tumor cell apoptosis was investigated by flow cytometry and Hoechst staining. Caspase-3 activity assay and Western blot were performed to investigate the possible mechanisms. <b><i>Results:</i></b> After silencing ALT- and telomerase mechanism-related genes, Bax and Bcl-2 were increased, and nuclear factor (NF)-κB translocation and PI3K/Akt phosphorylation were inhibited. <b><i>Conclusions:</i></b> The inhibition of telomere-related genes inhibited the growth of laryngeal squamous cell carcinoma by promoting cell apoptosis via the PI3K/Akt pathway.