The Study On The Effect And Mechanism Of EGCG On Acute Promyelocytic Leukemia Cell Line NB4 Biology

PART Ⅰ EGCG induces NB4 cell apoptosis by activating p38αMAPK–Bax pathwayObjective: To investigate whether EGCG can induce NB4 cell apoptosis and relevant molecular mechanism in this study.Methods: NB4 cell was treated with EGCG in different concentration,and it was pretreated with p38αMAPK inhibitor PD169316 for 30 minutes,and then treated with EGCG in certain concentration.The proliferation of NB4 cell was detected by CCK-8 kit.The apoptosis of NB4 cell was measured by FITC-Annexin V/PI double staining assay.And Western-Blot was used to detect the protein expression levels of p38αMAPK,p-p38αMAPK,Bcl-2 and Bax protein.Results: As the rise of EGCG concentration,CCK-8 assay showed that EGCG can inhibit the proliferation of NB4 cell in a concentration manner;FCW revealed EGCG can induce NB4 cell apoptosis;Meanwhile Western-Blot found the protein expression level of p-p38αMAPK and Bax was increased,but the protein expression level of Bcl-2 was decreased.After treated with PD169316,CCK-8 assay revealed the ability of EGCG-inhibited cell proliferation was weaken,meanwhile FCW showed the ability of EGCG-induced cell apoptosis was also weaken;Western-Blot found the protein expression level of Bax was decreased,but the Bcl-2 was not changed.Conclusion: EGCG induces NB4 cells apoptosis may through the activation of p38αMAPK-Bax pathway.PART Ⅱ EGCG induces NB4 cell apoptosis by SHP-1-mediated p38αMAPK–Bax pathwayObjective: To investigate whether EGCG can induce NB4 cell apoptosis by SHP-1-mediated p38αMAPK-Bax pathway in this study.Methods: NB4 cell was treated with EGCG in different concentration,and it was pretreated with SHP-1 inhibitor NSC87877 for 30 minutes,and then treated with EGCG in certain concentration.The proliferation of NB4 cell was detected by CCK-8 kit.The apoptosis of NB4 cell was measured by FITC-Annexin V/PI double staining method.And Western-Blot was used to detect the expression levels of SHP-1,p38αMAPK,p-p38αMAPK and Bax protein.Results: Western-Blot results showed that EGCG can increase the expression level of SHP-1 protein obviously.After treated with SHP-1 inhibitor NSC87877,the expression level of SHP-1 was obvious decreased.Meanwhile CCK-8 assay showed that the ability of EGCG-inhibited cell proliferation was weaken,FCW showed the ability of EGCG-induced cell apoptosis was also weaken;Western-Blot revealed the protein expression level of p-p38αMAPK and Bax was decreased,but the expression level of p38αMAPK protein was not changed.Conclusion: EGCG induces NB4 cell apoptosis by SHP-1-mediated p38αMAPK-Bax pathway.