ABSTRACT
Objective:To study the influence of chloroquine combined with decitabine in the apoptosis of leukemia K562 cells and KG-1a1Aor1a cells,to explore the effect of autophagy on the leukemia cell apoptosis induced by decitabine,and to clarify its mechanism.Methods:The leukemia K562 and KG-1a1Aor1a cells were cultivated in vitro and divided into blank control group,decitabine group (10 μmol · L 1) and chloroquine (50 μmol · L 1) combined with decitabine group (combined group).The leukemia cells in combined group were pre-treated with chloroquine for 6 h before experiment.After treatment with drugs for 24 and 48 h,the number of cells was detected and by CCK-8 method the inhibitory rates of proliferation cells were calculated;the apoptotic rates and mitochondrial membrane potential were detected by flow cytometry.Q-PCR method was carried out to determine the gene expression levels of Atg7 and Atg12,and Western blotting was used to test the protein expression of LC3.Results:After treatment for 24 and 48 h,the number of K562 and KG-1a1Aor1a cells in decitabine group and combined group were decreased compared with blank control group (P＜0.05 or P＜0.01);the apoptotic rates and mitochondrial membrane potential were remarkably increased (P＜0.05 or P＜0.01).Compared with decitabine group,the number of K562 and KG-1a1Aor1a in combined group was significantly decreased,and the apoptotic rates were remarkably increased (P＜0.05).After treatment for 24 h,the expression levels of Atg7,Atg12 and LC3-Ⅱ/LC3-Ⅰ in the leukemia K562 and KG-1a1Aor1a cells in decitabine group were significantly increased compared with blank control group (P＜0.05 or P＜0.01);the expression levels of Atg7,Atg12 and LC3-Ⅱ/LC3-Ⅰ in the leukemia K562 and KG-1a1Aor1a cells in combined group were significantly decreased compared with decitabine group (P＜0.05 or P＜0.01).Conclusion:Decitabine could promote the apoptosis of leukemia cells,and the inhibition of autophagy by chloroquine can promote the apoptosis induced by decitabine.
ABSTRACT
Objective:To study the influence of chloroquine combined with decitabine in the apoptosis of leukemia K562 cells and KG-1a1Aor1a cells,to explore the effect of autophagy on the leukemia cell apoptosis induced by decitabine,and to clarify its mechanism.Methods:The leukemia K562 and KG-1a1Aor1a cells were cultivated in vitro and divided into blank control group,decitabine group (10 μmol · L 1) and chloroquine (50 μmol · L 1) combined with decitabine group (combined group).The leukemia cells in combined group were pre-treated with chloroquine for 6 h before experiment.After treatment with drugs for 24 and 48 h,the number of cells was detected and by CCK-8 method the inhibitory rates of proliferation cells were calculated;the apoptotic rates and mitochondrial membrane potential were detected by flow cytometry.Q-PCR method was carried out to determine the gene expression levels of Atg7 and Atg12,and Western blotting was used to test the protein expression of LC3.Results:After treatment for 24 and 48 h,the number of K562 and KG-1a1Aor1a cells in decitabine group and combined group were decreased compared with blank control group (P＜0.05 or P＜0.01);the apoptotic rates and mitochondrial membrane potential were remarkably increased (P＜0.05 or P＜0.01).Compared with decitabine group,the number of K562 and KG-1a1Aor1a in combined group was significantly decreased,and the apoptotic rates were remarkably increased (P＜0.05).After treatment for 24 h,the expression levels of Atg7,Atg12 and LC3-Ⅱ/LC3-Ⅰ in the leukemia K562 and KG-1a1Aor1a cells in decitabine group were significantly increased compared with blank control group (P＜0.05 or P＜0.01);the expression levels of Atg7,Atg12 and LC3-Ⅱ/LC3-Ⅰ in the leukemia K562 and KG-1a1Aor1a cells in combined group were significantly decreased compared with decitabine group (P＜0.05 or P＜0.01).Conclusion:Decitabine could promote the apoptosis of leukemia cells,and the inhibition of autophagy by chloroquine can promote the apoptosis induced by decitabine.
ABSTRACT
Objective:To observe the effects of allogeneic compact bone derived-mesenchymal stem cells ( CB-MSCs) on pro-liferation and differentiation of T cells,and investigate the molecular mechanisms of the immunosuppressive ability.Methods:With an established co-culture system of CB-MSCs and mouse spleen lymphocytes ( SP) in vitro,we observed the effects of CB-MSCs on prolif-eration,apoptosis and cell cycle of SP by MTS/PES assay and flow cytometry.Also,we measured the effects of CB-MSCs on regulatory T cells ( Treg) ratio and expressions of CCR5,CCR7 and CXCR3 in SP.Results:CB-MSCs could obviously inhibit the PHA-stimulated SP proliferation with a dose-dependent manner;MSCs could significantly inhibit the spontaneous apoptosis of SP and induce SP cell cycle G0/G1 phase arrest.After co-culture with SP,CB-MSCs could obviously increase the proportion of Treg in SP,down-regulate the expression of CXCR3 and CCR5,as well as up-regulate the expression of CCR7.Conclusion: Allogeneic CB-MSCs can significantly inhibit cell proliferation of SP,the mechanisms mainly involved the G0/G1 cell cycle arrest rather than apoptosis induction.In addition, CB-MSCs can exert immunomodulatory effects by increasing the Treg ratio,regulating the expressions of chemokine receptors.
ABSTRACT
A new sesquiterpene hydroquinone (1) was isolated from a deep sea sediment derived fungus, Phialocephala sp.. Its structure and stereochemistry were established on the basis of spectroscopic data and optical rotation. This compound was tested for cytotoxicity against P388 (murine leukemia cell) and K562 (human leukemia cell) cell lines, and displayed strong cytotoxic effects with IC50 value of 0.16 and 0.05 micromol x L(-1), separately.