The Importance Of Steroid Receptor Coactivator-3 (SRC-3) On The Treatment Of Malignant Hematological Diseases By Natural Drugs

Partâ… Gambogic acid induces G0/G1 arrest and apoptosisinvolving inhibition of SRC-3 and inactivation of Aktpathway in K562 leukemia cellsObjective:To investigate the anticancer effects and the molecular mechanisms ofGambogic acid(GA) on K562 cells and to provide more theories for clinical application.Methods:The effects of Gambogic acid on the growth ofK562 cells were studied by MTTassay.Annexin V/PI double-labeled cytometry and transmission electron microscopy wereused to detect cell apoptosis.A propidium iodide method was used to study cell cycledistribution.Quantitative real-time PCR was employed to assess the expression levels ofsteroid receptor coactivator-3 (SRC-3) and apoptosis related gene Bcl-2.Western blottingwas employed to assess the expression levels of SRC-3,Akt,pAkt,S6K1,pS6K1,GSK-3β,pGSK-3βand Bcl-2.Results:(1) GA was able to inhibit cell proliferation in K562 cells in a time- and dose-dependent manner,with 24h IC₅₀ value of 1.9±0.1μmol/L.(2) Gambogic acid inducedapoptosis of K562 cells in a dose-dependent manner,which was accompanied by typicalapoptotic morphological changes.(3) GA induced cell-cycle arrest in G0/G1 phase in K562cells.(4) GA treatment downregulated the expression of SRC-3 and inhibited the activity ofAkt kinase and its downstream targets p70 S6 kinase 1 (S6K1) and glycogen synthasekinase 3β(GSK-3β) without changes in total protein levels of these three proteins in K562cells,accompanied by decreased expression of the apoptosis related gene Bcl-2.Conclusion:GA might exhibit its strong antitumor effects via the interruption of SRC-3.Partâ…¡Deguelin induces apoptosis involving inhibition of SRC-3 andNF-κB pathway in Jurkat cellsObjective:To investigate the anticancer effects and the molecular mechanisms of deguelin onJurkat cells and to provide more theories for clinical application.Methods:The effects of deguelin on the growth of Jurkat cells were studied by MTT assay.Terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay andtransmission electron microscopy were used to detect cell apoptosis.A propidium iodidemethod was used to study cell cycle distribution.RT-PCR and western blotting were employedto assess the expression levels of steroid receptor coactivator-3 (SRC-3),nuclear factor-κB(NF-κB) and some apoptosis related genes,including Bcl-2 and Bcl-xL.Results:(1) Deguelin was able to inhibit cell proliferation in Jurkat cells in a time- anddose-dependent manner,with 24h IC₅₀ value of 43.73±0.35 nmol/L and 48h IC₅₀ value of28.96±0.29 nmol/L.(2) Deguelin induced apoptosis in Jurkat cells in a dose-dependentmanner in vitro.After treatment with 40nmol/l deguelin for 24h,apoptotic bodies containingnuclear fragments and the chromatin condensed were found by Transmission electronmicroscopy.Jurkat cells treated with 40nmol/l deguelin for 24h also showed positive TUNELstaining.The percentage of TUNEL positive cells was 12.8±0.85%,compared with only 1.1±0.09% TUNEL positive cells in the untreated samples (P＜0.01).(3) Deguelin induced cell-cycle arrest in G0/G1 phase in Jurkat cells.(4) Deguelin could downregulate theexpression of SRC-3 and its downstream transcription factor NF-κB,which thus influencedthe expression of apoptosis related genes Bcl-2 and Bcl-xL.Conclusion:Deguelin presents potent effects on growth-arrest and apoptosis-induction inJurkat cells in vitro via the interruption of SRC-3.Partâ…¢Effects of deguelin on the regulation of SRC-3 in MM cells in vitroObjective:To investigate the anticancer effects and the molecular mechanisms of deguelin onRPMI-8226 cells.Methods:The effects of deguelin on the growth of RPMI-8226 cells were studied by MTTassay.Hoechst 33258 staining and Annexin-V FITC/PI double-labeled cytometry wereused to detect cell apoptosis.Transwell invasion assay was used to assess the role ofdeguelin on RPMI-8226 cell invasion.RT-PCR was employed to assess the mRNAexpression levels of SRC-3 and NF-κB,whereas,SRC-3 and NF-κB protein expression andlocalization were determined by using immunohistochemistry method.GelatinZymography was used to detect the gelatinolytic activity of secreted MMP-2 and -9.Results:(1) Deguelin presented striking proliferation inhibition potency on RPMI-8226cells in vitro,with 24h IC50 value of 54.55±0.40nmol/L.(2) Deguelin induced apoptosis inRPMI-8226 cells in a dose-dependent manner in vitro,which was accompanied by typicalapoptotic morphological changes.(3) Deguelin could inhibit RPMI-8226 cell invasion.(4)Deguelin could downregulate the expression of SRC-3 and its downstream transcriptionfactor NF-κB,which thus influenced the gelatinolytic activity of secreted MMP-2 and -9.Conclusion:Deguelin exhibit its strong antitumor effects via the interruption of SRC-3.