No abstract

Lista de abreviaturas Lista de Abreviaturas ADP Adenosina 5´-difosfato ANT Translocador de nucleotídeos de adenina ATP Adenosina 5´-trifosfato BPS Ácido dissulfônico da batofenantrolina BSA Albumina de soro bovino β β β β-OH β-hidroxibutirato CCCP Carbonilcianeto-m-clorofenilidrazina CLAE Cromatografia líquida de alta eficiência CsA Cisclosporina A CAVD Canal aniônico voltagem-dependente DNP 2,4-dinitrofenol DPPH 2,2-difenil-1-picrilidrazil DTNB Ácido 5,5´-ditio-bis-2-nitrobenzóico E Extrato de tamarindo EDTA Ácido etilenodiamino tetracético EGTA Ácido etilenoglicol bis-(β-aminoetil éter)-N,N,N´,N´-tetracético EROs Espécies reativas de oxigênio ERNs Espécies reativas de nitrogênio ERONs Espécies reativas de oxigênio e nitrogênio FAD Flavina adenina dinucleotídeo FADH 2 Flavina adenina dinucleotídeo (forma reduzida) FCCP Carbonilcianeto-p-trifluormetoxifenilidrazina GPx Glutationa peroxidase GRd Glutationa redutase GSH Glutationa reduzida GSSG Glutationa oxidada H 2 O 2 Peróxido de hidrogênio HEPES Ácido (N-[2-hidroxietil] piperazina-N´-[etanossulfônico]) MDA Malondialdeído NBT Nitroblue tetrazolium NAD + Nicotinamida adenina dinucleotídeo NADH Nicotinamida adenina dinucleotídeo (forma reduzida) NAD(P) + Nicotinamida adenina dinucleotídeo fosfato NAD(P)H Nicotinamida adenina dinucleotídeo fosfato (forma reduzida) NEM N-etilmaleimida NO Óxido nítrico PTP Poro de transição de permeabilidade mitocondrial

Autophagy is a process by which lysosomes degrade and recycle long‐lived proteins and cellular organelles. It degrades cellular components that are worn out/damaged or needed to generate substrates to maintain cellular energy homeostasis under conditions of limited nutrients or stress. Cells of squamous cell cancer of the head and neck (HNSCC), which is the fifth most common malignancy in the world, have a high expression of the SET protein and under oxidative stress they perform the autophagic process. Therefore, the aim of our study is to verify a potential involvement of the SET protein on the autophagic process in these cells exposed to oxidative stress. Initially, knockdown of the SET protein (siSET) was performed in the Cal 27 cell line, in which oxidative stress was induced with tert‐butylhydroperoxide (t‐BHP). Proteins involved in autophagy as LC3B, Beclin‐1 and p62 were analyzed by immunoblotting. The siSET in Cal 27 cells caused an increase in the level of these proteins, which was slightly and significantly reduced after 4 and 8 hours of exposure to t‐BHP, respectively. Acids vacuoles identified by immunofluorescence, which are indicative of autophagy, were also found in Cal 27 cells for siSET and treatment with t‐BHP. Therefore, we believed that SET protein is important for the modulation of autophagy in HNSCC. PCR array assays are now in progress in order to assess potential genes involved in this regulation.FAPESP and CAPES