Soyasapogenol B Attenuates Laryngeal Carcinoma Progression through Inducing Apoptotic and Autophagic Cell Death

: Soyasapogenol B (Soy B), a constituent of soybean, has been shown to exhibit antitumor activities against different types of cancers. However, to our knowledge, no studies so far have investigated the effect of Soy B in human laryngeal carcinoma. This study, therefore, aimed to determine the effect of Soy B in human laryngeal carcinoma cell lines HeP-2 and TU212 and to elucidate the possible underlying mechanisms by which Soy B can induce its antitumor effects. The results showed that Soy B effectively attenuated the cell growth by causing G0/G1 phase cell cycle arrest in laryngeal carcinoma cell lines. Moreover, the percentage of apoptotic and autophagic cells dramatically increased upon exposure to Soy B. Western blotting results confirmed that Soy B can alter the expression levels of established markers of apoptosis and autophagy. Interestingly, both apoptosis inhibitor (ZVAD-fmk) and autophagy inhibitor (3-MA) could partially reverse the effect of Soy B, while blocking autophagy did not cause obvious alteration in the percentage of apoptotic cells. Similarly, in vivo studies validated that Soy B could effectively reduce the size of the tumor and induce apoptosis and autophagy in tumor tissues. Collectively, these results suggested that Soy B can exert anticancer activities against laryngeal carcinoma through inducing apoptotic and autophagic cell death. Our study highlighted the potential role of Soy B as a chemotherapeutic agent for laryngeal carcinoma. Anat Rec, 2019. © 2019 American Association for Anatomy.