Drug resistance and relapse are the major challenge for current treatment of acute leukemia. It is critical for ultimately curing leukemia to overcome chemoresistance of leukemic stem cells (LSC) and to eradicate LSC. Recent studies have found that abnormal activated Hedgehog (HH) signaling pathway plays an important role in a wide variety of tumors and regulates multi-drug resistance of LSC. This review briefly summarizes the molecular mechanism of HH signal pathway inducing drug resistance of LSC and leading to novel strategies for eradicating LSC.
Drug Resistance, Neoplasm ; Hedgehog Proteins ; metabolism ; Humans ; Leukemia ; metabolism ; Neoplastic Stem Cells ; drug effects ; Signal Transduction

OBJECTIVETo investigate the apoptosis induced by manumycin in U937 and HL-60 cell lines, and to explore the role of mitochondria apoptotic pathway in manumycin-inducing apoptosis.

METHODSLeukemic cells line U937 and HL-60 were treated by manumycin at 2 micromol/L for different time. Apoptosis of leukemia cells was detected by flow cytometry. The cytosolic proteins were extracted using a digitonin buffer. The protein expression of cytochrome C, caspase-9, caspase-8, and caspase-3 were determined by western blot. Mitochondrial membrane potential was detected by JC-1.

RESULTSIn U937 and HL-60 cells, manumycin induced mitochondrial depolarization after 6 h treatment. The average red/green fluorescence ratios at 6 h were significantly (P < 0.01) lower than those at time 0, being 0.51 +/- 0.07 and 0.41 +/- 0.06 for control group respectively. Manumycin induced cytochrome C release from the mitochondria into the cytosol after 6 h treatment, and activated caspase-9, caspase-8, and caspase-3 after a 16h treatment. The broad-spectrum caspase-inhibitor Z-VAD-fmk at 50 micromol/L was able to inhibit caspase cleavage completely, but only reduced the manumycin-induced apoptosis rates by 51.69% and 56.47% in U937 and HL-60, respectively.

CONCLUSIONManumycin induced apoptosis in U937 and HL-60 cell lines via mitochondria apoptotic pathway.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Cytochromes c ; metabolism ; HL-60 Cells ; Humans ; Mitochondria ; drug effects ; metabolism ; physiology ; Polyenes ; pharmacology ; Polyunsaturated Alkamides ; pharmacology

OBJECTIVETo study the cytotoxic effect of allogenetic natural killer (NK) cells in vitro on human CD34+ acute myelogenous leukemia cells.

METHODSCD34 expression on acute myelogenous leukemia KG1a cells was detected by flow cytometry. KG1a cells were co-cultured at different effector-to-target (E:T) ratios with NK cells isolated from 5 healthy individuals using magnetic cell sorting. Lactate dehydrogenase (LDH) release assay was employed to examine the cytolysis of KG1a cells in the co-culture, and the inhibition rate of the KG1a cell colony formation in methylcellulose was determined with K562 cells sensitive to NK cells as the control.

RESULTSA expression rate as much as (98.0-/+1.1)% was detected for CD34 antigen on KG1a cells, and the isolated NK cells (CD3(-)CD16+CD56+ cells) had a purity of (93.2-/+3.7)% after magnetic cell sorting. Allogenetic NK cells exhibited obvious cytotoxicity and colony inhibition in vitro against KG1a cells at different E:T ratios, and the effects were significantly enhanced as the E:T ratios increased (P<0.05). At the same E:T ratio, the cytotoxicity and colony inhibition rate of allogenetic NK cells against KG1a cells was lower than those against K562 cells (P<0.05).

CONCLUSIONAllogenetic NK cells exhibit obvious cytotoxicity and colony formation against CD34+ acute myelogenous leukemia cells.

Antigens, CD34 ; immunology ; Coculture Techniques ; Cytotoxicity, Immunologic ; Flow Cytometry ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology ; Leukemia, Myeloid, Acute ; immunology

OBJECTIVETo investigate the allo-NK cell-mediated killing effect enhanced by decitabine on leukemia stem cells(LSC) and the underlying mechanisms.

METHODSLSC were separated from KG1a cells by using immunomagnetic beads. Allo-NK cells were isolated and purified from PBMC of healthy donors. Cytotoxicity of allo-NK cells against LSC were measured by LDH releasing assay. The apoptosis induced by allo-NK cells in LSC and the expressions of NKG2D ligands including MICA/B and ULBP1-3 on LSC were detected by flow cytometry.

RESULTSThe killing rate of allo-NK cells to LSC treated with 10 µmol/L decitabine for 24 hours was significant higher than that to LSC without treatment(60.52%±3.52% vs 22.08%±2.07%, 73.93%±2.33% vs 28. 99%±3.13%, 83.08%±1.32% vs 36.44%±2.40%, respectively)at the effector-target ratios of 5:1, 10:1, 20:1 (P<0.05). At the effector-target ratio of 10:1, decitabine significantly enhanced the apoptosis of LSC induced by allo-NK cells (7.84%±0.34% vs 3.33%±0.64%)(P<0.05). The expressions of NKG2D ligands(MICA/B,ULBP1,ULBP2,ULBP3) on LSC treated with decitabine 10 µmol/L for 24 hours were significantly increased (P<0.05).

CONCLUSIONDecitabine may enhance the allo-NK cell-mediated killing effects on LSC by up-regulation of the expressions of NKG2D ligands on LSC.

BACKGROUNDData on the epidemiology of hypertension in Chinese non-dialysis chronic kidney disease (CKD) patients are limited. The aim of the present study was to investigate the prevalence, awareness, treatment, and control of hypertension in the non-dialysis CKD patients through a nationwide, multicenter study in China.

METHODSThe survey was performed in 61 tertiary hospitals in 31 provinces, municipalities, and autonomous regions in China (except Hong Kong, Macao, and Taiwan). Trained physicians collected demographic and clinical data and measured blood pressure (BP) using a standardized protocol. Hypertension was defined as systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg, and/or use of antihypertensive medications. BP < 140/90 mmHg and < 130/80 mmHg were used as the 2 thresholds of hypertension control. In multivariate logistic regression with adjustment for sex and age, we analyzed the association between CKD stages and uncontrolled hypertension in non-dialysis CKD patients.

RESULTSThe analysis included 8927 non-dialysis CKD patients. The prevalence, awareness, and treatment of hypertension in non-dialysis CKD patients were 67.3%, 85.8%, and 81.0%, respectively. Of hypertensive CKD patients, 33.1% and 14.1% had controlled BP to < 140/90 mmHg and < 130/80 mmHg, respectively. With successive CKD stages, the prevalence of hypertension in non-dialysis CKD patients increased, but the control of hypertension decreased (P < 0.001). When the threshold of BP < 130/80 mmHg was considered, the risk of uncontrolled hypertension in CKD 2, 3a, 3b, 4, and 5 stages increased 1.3, 1.4, 1.4, 2.5, and 4.0 times compared with CKD 1 stage, respectively (P < 0.05). Using the threshold of < 140/90 mmHg, the risk of uncontrolled hypertension increased in advanced stages (P < 0.05).

CONCLUSIONSThe prevalence of hypertension Chinese non-dialysis CKD patients was high, and the hypertension control was suboptimal. With successive CKD stages, the risk of uncontrolled hypertension increased.

Adult ; Aged ; Awareness ; Female ; Humans ; Hypertension ; complications ; epidemiology ; therapy ; Male ; Middle Aged ; Prevalence ; Renal Insufficiency, Chronic ; complications