Autophagy interplays with apoptosis and cell cycle regulation in the growth inhibiting effect of Trisenox in HEP-2, a laryngeal squamous cancer.
Laryngeal squamous cell carcinoma (LSCC) is the most common among several types of head and neck cancers. Current treatments have a poor effect on early and advanced cases, and further investigations for novel agents against LSCCs are desirable. In this study, we elucidate the cytotoxic enhancing effect of arsenic trioxide (As2O3) combined with L-buthionine sulfoximine (BSO) in LSCC. The effect of BSO with As2O3 or Cisplatin (CDDP) on cell viability was examined using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The reactive oxygen species (ROS) levels, cell cycle, and apoptosis were measured by flow cytometry using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), propidium iodide (PI) and annexin V/PI. The acidic vacuolar organelles were visualized by fluorescence microscope and quantified using flow cytometry. Neither CDDP nor As2O3 when used alone reduced the cell viability. BSO was found to enhance only As2O3 sensitivity, leading to G2/M arrest and autophagy with no correlation of ROS induction. This result suggests that modulation of glutathione enhances autophagy, which interplays with apoptosis. In this study, we obtained initial preclinical evidence for the potential efficacy of these drugs in a combined therapy protocol.
Departamento de Estomatologia, Hospital AC Camargo, São Paulo, Brazil.
Débora Lima
DL
Pereira
Ana Carolina
AC
Dos Santos Ferreira
Giselle Pinto
GP
de Faria
Jolie Kiemlian
JK
Kwee
D017209:Apoptosis / Q000187:drug effects*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D007822:Laryngeal Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D010087:Oxides / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077195:Squamous Cell Carcinoma of Head and Neck
D001152:Arsenicals; D010087:Oxides; D017382:Reactive Oxygen Species; D002945:Cisplatin; D000077237:Arsenic Trioxide