Inducement Of Tumor Cell Autophagy And Cell Cycle Analysis

BACKGROUND & OBJECTIVEAutophagy is the main phenomenon of typeâ…¡programmed cell death which is also named as autophagic cell death and autophagy has a close relationship with the autophagic cell death. Researchers has been explored deeply the relationship of apoptosis and cell cycle, but little is known about the relationship of autophagic cell death and cell cycle. This study was to observe the correlation of autophagy induced by different methods to cell cycle.METHODSExponentianlly logical growing HeLa and SW480 cells, and peripheral blood lymphocytes (PBLs) from healthy donors, with or without 48 h stimulation of phytohemagglutinin (PHA), were treated with Hanks'solution to produce starvation or vincristine. Confocal laser microscope and transmission electron microscope (TEM) were used to detect autophagy; Flow cytometry (FCM) was innovatively used to detect the cell cycle of autophagic cells with dipl-parameters of Microtubule-associated protein 1 light chain 3 (MAP1-LC3-II)/PI.RESULTSAutophagy of HeLa and SW480 cells induced by starvation or vincristine was observed in G1,S,G2/M phases and increased along with the inducement time; no autophagy was observed in unstimulated PBLs. The positive rate of LC3-II, indicating the occurrence of autophagy, was lower than 2.62% when induced by starvation in Hanks'solution for 48 h, or 6.16%when induced by vincristine for 48 h. After PBLs were stimulated into cell cycle by PHA, autophagy were markedly detected 2 h after the indicated inducements.CONCLUSIONSMAP1- LC3-II / DNA dipl- parameter analysis by FCM is an convenient and reliable method for simultaneously analysing autophagy and cell cycle. Autophagy could be induced when cells are in cell cycle, while the cells in G0 phase are insensitive to the inducers.