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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.
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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.
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BACKGROUND:Cytotoxicity of graphene oxide to normal cel s is relatively low, but whether graphene oxide loaded with doxorubicin has some effects on malignant cel s is rarely reported. OBJECTIVE:To explore the cytotoxicity of graphene oxide loaded with doxorubicin on multiple myeloma cel s. METHODS:Multiple myeloma cel line RPMI8226 in logarithmic phase was selected, cultured and divided into four groups, including graphene oxide loaded with doxorubicin, doxorubicin and graphene oxide groups as wel as control group with no intervention. After 24 hours of culture, the cel activity was detected by cel counting kit-8 method, and the cel cycle and apoptosis were detected using flow cytometry. RESULTS AND CONCLUSION:Plump-shaped cel s with translucent and clear cytoplasm were found in the control group;cel s with relatively translucent cytoplasm, and even a few shrunken cel s appeared in the graphene oxide group;cel ular morphology was in a heterogeneity, apoptotic bodies appeared in the doxorubicin group;the cel s was significantly reduced in size, presenting more obvious shrinkage and apoptotic bodies in the group of graphene oxide loaded with doxorubicin. The cel survival rate in the graphene oxide loaded with doxorubicin, doxorubicin and graphene oxide groups was significantly lower than that in the control group (P<0.05), and this indicator was significantly lower in the group of graphene oxide loaded with doxorubicin than the graphene oxide group (P<0.05). The apoptotic rate in the group of graphene oxide loaded with doxorubicin and doxorubicin group was significantly higher than those in the graphene oxide and control groups (P<0.05), respectively. Additional y, there were no significant differences in the cel cycle among groups. These results show that graphene oxide loaded with doxorubicin has a stronger cytotoxicity, and can induce apoptosis in human multiple myeloma cel s.
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<p><b>OBJECTIVE</b>To summarize a case of acute myeloid leukemia（AML） with severe infection and a rare translocation of t（10;11）（q22;q23）who got spontaneous remission.</p><p><b>METHODS</b>The laboratorial examination results and clinical data in this case were summarized in couple with the light of published literatures.</p><p><b>RESULTS</b>Like most of the spontaneous remission cases, severe infection happened to this case of AML patient, but the different point was that a rare translocation of t（10;11）（q22;q23）was disclosed in this patient. There were only 6 cases of this kind of translocation reported by the literatures up to now. This patient got spontaneous remission after the controlled infection without any chemotherapy. The rare translocation of t（10;11）（q22;q23）disappeared after he got remission.</p><p><b>CONCLUSION</b>Spontaneous remission of acute leukemia was a rare phenomenon, the underlying mechanism was unclear, maybe due to the inflammatory factors triggered by infection, or the activated immune system by the infection, or even the role of gene mutation factors. Accumulating data might shed insight into this rare kind of disease.</p>
Subject(s)
Humans , Male , Acute Disease , Chromosomes, Human, Pair 10 , Chromosomes, Human, Pair 11 , Leukemia, Myeloid, Acute , Remission, Spontaneous , Translocation, GeneticABSTRACT
AIM: To investigate the role of mitochondrial ceramidase in mitochondrial functions, especially in the regulation of apoptosis. METHODS: pCDNA3.1/His-MtCDase plasmid, containing mitochondrial ceramidase cDNA sequence, was transfected into K562 cells by liposome, and G418 was used to screen the positive clones. A stable transfected K562 cell line was established and defined as ‘K562TC’. The differences between K562 and K562TC cells in serum withdrawal resistance and Bcl-2 protein expression were evaluated by annexin V/PI test, flow cytometry and Western blotting, respectively. RESULTS: K562TC cells with elevated Bcl-2 protein expression level identified by FCM or Western blotting showed stronger resistance to apoptosis induced by serum withdrawal than their parental cells. Inhibition of mitochondrial ceramidase expression in K562TC cells by its specific antisense oligodeoxynucleotide was correlated with a decrease in Bcl-2 protein level. N, N'-dimethylsphingosine (DMS), a sphingosine kinase inhibitor, depleted intracellular sphingosine-1-phosphate (SPP) production, also abrogated Bcl-2 protein expression in K562TC cells, while exogenous sphingosine-1-phosphate up-regulated Bcl-2 protein level in K562 cells. CONCLUSION: Mitochondrial ceramidase overexpression in K562 cells leads to markedly elevated level of Bcl-2 protein and results in more resistance to serum withdrawal. This effect is initiated not by sphingosine, the direct metabolite of mitochondrial ceramidase, but via sphingosine-1-phosphate, its phosphorylated form, indicating that mitochondrial ceramidase, through its sphingoid metabolite sphingosine-1-phosphate, up-regulates Bcl-2 protein expression in K562 cells.