The Effect Of Hypoxia Or Tumor Necrosis Factor Alpha On All Trans Retinoic Acid Induced Promyelocyte Leukemia Cell Apoptosis

Objective:All trans retinoic acid(ATRA) can induce differentiation of Acute promyelocytic leukemia(APL)cells, resulting to a higher remission rate, lower incidence of bleeding.Severe infection usually result from a lack of oxygen to the body of the environment.Tumor necrosis factor(TNF alpha) is a kind of effect of the cytokines, have antitumor effect.This topic detect the expression of TNFR1, apoptosis and cell membrane, study the effect of hypoxia on ATRA induced APL cells apoptosis and the expression of TNFR1 and CD11 b, study the effect of TNF alpha on ATRA induced APL cells apoptosis and differentiation and relevant mechanisms are discussed. Methods:This topic is divided into two parts:The first part includes the following four experiment content:1. Hypoxia model is established.2. The effect of hypoxia on differentiation of NB- 4 cell proliferation and apoptosis.3. The effect of hypoxia on differentiation of NB- 4 cell surface expression of CD11 b.4. The effect of hypoxia on differentiation of NB- 4 cell membrane expression of TNFR1 strength.The second part includes the following four experiment content:1. The effect of TNF alpha combined ATRA on NB- 4 cell proliferation,differentiation and apoptosis.2. The effect of TNF alpha combined ATRA on NB- 4 cell surface expression of TNFR1. Results:The first part of the results showed, compared with oxygen group:1. The cell count results show that the hypoxia made differentiation of NB- 4 cell proliferation speed slower.2. FITC Annexin V/PI staining results show that the hypoxia made differentiation of NB- 4 cell apoptosis and necrosis restrained.3. Flow cytometry results showed that hypoxia made differentiation of NB- 4 cell CD11 b positive percentage increased slightly.4. Immunofluorescence staining results showed that hypoxia made differentiation of NB – 4 cell expression of TNFR1 intensity weaken.The second part, according to the results and without TNF alpha group comparison:1. The cell count showed that TNF alpha combined ATRA make NB- 4 cell proliferation more slowly.2. FITC Annexin V/PI staining showed that TNF alpha combined ATRA make NB- 4 cell apoptosis rate is higher.3. Flow cytometry showed that TNF alpha combined ATRA make NB- 4 cell CD11 b an even greater percentage of positive cells after 2 days; ATRA combined TNF alpha group in the process of the differentiation of TNFR1 positive cells was down. Conclusion:1. Hypoxia inhibits ATRA NB- 4 cell apoptosis induction, activate part has to mature neutrophils differentiation NB- 4 cell, make its expression more CD11 b.Its inhibition has differentiation mechanism of NB- 4 cell apoptosis may be an oxygen reduced the number of cell surface receptors TNFR1 death.2. TNF alpha can strengthen ATRA, induction of cell apoptosis and differentiation of NB- 4, its mechanism may be the TNF alpha combined with cell surface receptor TNFR1 death, launched the TNFR1 mediated apoptosis mechanism.