Apoptotic effect of Bulbine Natalensis and Chlorophytum Comosum in myelogenous Leukemia K562 cell line / Efeito apoptótico da natalensia bulbina e do clorofito comoso na linhagem celular mielogênea da leucemia K562

Abstract Bulbine natalensis and Chorophytum comosum are potential medicinal source for the treatment of cancers. Chronic myeloid leukaemia is a hematopoietic stem cells disorder treated by tyrosine kinase inhibitors but often cause recurrence of the leukaemia after cessation of therapy, hence require alternative treatment. This study determines the anti-cancer effect of leaf, root and bulb methanolic and aqueous extracts of B. natalensis and C. comosum in chronic human myelogenous leukaemia (K562) cell line by MTT, Hoechst bis-benzimide nuclear and annexin V stain assays. The root methanolic extract of B. natalensis and C. comosum showed a high cytotoxicity of 8.6% and 16.7% respectively on the K562 cell line at 1,000 μg/ml concentration. Morphological loss of cell membrane integrity causing degradation of the cell and fragmentation were observed in the root methanolic extract of both plants. A high apoptosis (p < 0.0001) was induced in the K562 cells by both leaf and root extracts of the C. comosum compared to the B. natalensis. This study shows both plants possess apoptotic effect against in vitro myelogenous leukaemia which contributes to the overall anti-cancer properties of B. natalensis and C. comosum to justify future therapeutic applications against chronic myelogenous leukaemia blood cancer.

Resumo Bulbine natalensis Baker e Chorophytum comosum (Thunb.) Jacques são potenciais fontes medicinais para o tratamento de cânceres. A Leucemia Mieloide Crônica (LMC) é um distúrbio das células-tronco hematopoiéticas que é tratado com inibidores da tirosina quinase, mas frequentemente, causa recorrência da leucemia após a interrupção da terapia, portanto, requer um tratamento alternativo. Este estudo determinou o efeito anticancerígeno de extratos metanólicos e aquosos de folha, raiz e bulbo de B. natalensis e C. comosum na linhagem celular de leucemia mieloide humana crônica (K562) por ensaios de MTT, Hoechst bis-benzimida nuclear e anexina V. O extrato metanólico da raiz de B. natalensis e C. comosum apresentou alta citotoxidade de 8,6% e 16,7% respectivamente, na linhagem celular K562 com a concentração de 1,000 μg / ml. Perda morfológica da integridade da membrana celular causando degradação dos núcleos, citoplasma e encolhimento celular foi observada no extrato metanólico da raiz de ambas as plantas. Uma alta apoptose (p <0,0001) foi induzida nas células K562 por extratos de folhas e raízes de C. comosum em comparação com B. natalensis. Este estudo mostrou que ambas as plantas possuem efeito apoptótico contra leucemia mieloide in vitro que contribui para as propriedades anticâncer gerais de B. natalensis e C. comosum para justificar futuras aplicações terapêuticas contra câncer de sangue de LMC.

Apoptotic effect of Bulbine Natalensis and Chlorophytum Comosum in myelogenous Leukemia K562 cell line

Abstract Bulbine natalensis and Chorophytum comosum are potential medicinal source for the treatment of cancers. Chronic myeloid leukaemia is a hematopoietic stem cells disorder treated by tyrosine kinase inhibitors but often cause recurrence of the leukaemia after cessation of therapy, hence require alternative treatment. This study determines the anti-cancer effect of leaf, root and bulb methanolic and aqueous extracts of B. natalensis and C. comosum in chronic human myelogenous leukaemia (K562) cell line by MTT, Hoechst bis-benzimide nuclear and annexin V stain assays. The root methanolic extract of B. natalensis and C. comosum showed a high cytotoxicity of 8.6% and 16.7% respectively on the K562 cell line at 1,000 g/ml concentration. Morphological loss of cell membrane integrity causing degradation of the cell and fragmentation were observed in the root methanolic extract of both plants. A high apoptosis (p 0.0001) was induced in the K562 cells by both leaf and root extracts of the C. comosum compared to the B. natalensis. This study shows both plants possess apoptotic effect against in vitro myelogenous leukaemia which contributes to the overall anti-cancer properties of B. natalensis and C. comosum to justify future therapeutic applications against chronic myelogenous leukaemia blood cancer.

Resumo Bulbine natalensis Baker e Chorophytum comosum (Thunb.) Jacques são potenciais fontes medicinais para o tratamento de cânceres. A Leucemia Mieloide Crônica (LMC) é um distúrbio das células-tronco hematopoiéticas que é tratado com inibidores da tirosina quinase, mas frequentemente, causa recorrência da leucemia após a interrupção da terapia, portanto, requer um tratamento alternativo. Este estudo determinou o efeito anticancerígeno de extratos metanólicos e aquosos de folha, raiz e bulbo de B. natalensis e C. comosum na linhagem celular de leucemia mieloide humana crônica (K562) por ensaios de MTT, Hoechst bis-benzimida nuclear e anexina V. O extrato metanólico da raiz de B. natalensis e C. comosum apresentou alta citotoxidade de 8,6% e 16,7% respectivamente, na linhagem celular K562 com a concentração de 1,000 g / ml. Perda morfológica da integridade da membrana celular causando degradação dos núcleos, citoplasma e encolhimento celular foi observada no extrato metanólico da raiz de ambas as plantas. Uma alta apoptose (p 0,0001) foi induzida nas células K562 por extratos de folhas e raízes de C. comosum em comparação com B. natalensis. Este estudo mostrou que ambas as plantas possuem efeito apoptótico contra leucemia mieloide in vitro que contribui para as propriedades anticâncer gerais de B. natalensis e C. comosum para justificar futuras aplicações terapêuticas contra câncer de sangue de LMC.

Effect of miR-141-5p/ZNF705A on adhesion of bone marrow mesenchymal stem cells in chronic myeloid leukemia cell-derived exosomes / 中国药理学通报

Aim To investigate the effect of miR-141-5p/ZNF705A in chronic myeloid leukemia(CML)cell-derived exosome(Exo)on the adhesion of bone marrow mesenchymal stem cells(BMSCs). Methods The morphology and size of Exo in peripheral blood from CML patients and K562 cells were examined by electron microscopy and NTA particle size analysis. The expressions of Exo and BMSCs marker molecules and adhesion proteins in K562 cells were detected by qRT-PCR and Western blot before and after transfection. The adhesion ability of BMSCs was detected by cell adhesion assay, and the cellular activity of BMSCs was examined using CCK-8. miR-141-5p binding to ZNF705A was detected by luciferase assay. Results qRT-PCR results showed that miR-141-5p expression was significantly reduced in both CML patients and K562 cell-derived Exo. qRT-PCR, Western blot and other results showed that BMSCs in CML patients had significantly reduced the expression of adhesion proteins CD44 and CXCL12, and were able to phagocytose K562 cell-derived Exo. Further, K562-derived Exo was found to reduce CD44 and CXCL12 expression and adhesion in Exo-promoted BMSCs compared with CD34+ cells. Meanwhile, the results of dual luciferase reporter assay verified that miR-141-5p targeted binding to ZNF705A. Finally, we found ZNF705A could be targeted by up-regulating miR-141-5p expression in Exo of K562 cells, which in turn inhibited the adhesion of BMSCs. Conclusions K562 cells down-regulate miR-141-5p expression in Exo and inhibit the adhesion function of BMSCs by targeting ZNF705A, thus regulating the bone marrow hematopoietic function in CML patients.

miR-145-5p and miR-203a-5p overcome imatinib resistance in myelogenous leukemic cells through metabolic reprogramming-Supplemenntary data

Imatinib is the most effective therapy for chronic myeloid leukemia (CML), but many patients eventually develop resistance to it after an initial satisfactory response. This study investigated the potential of three miRNAs (miR-106b-5p, miR-145-5p, miR-203a-5p) in overcoming imatinib resistance in leukemic cells. The imatinib-resistant K562 (IR-K562) cells were developed and transfected with one of the three miRNAs to evaluate their potency in overcoming imatinib resistance. The changes in the metabolic profile were studied using flux balance analysis (FBA) and the data was validated using qRT-PCR.Among the three miRNAs, the ectopic expression of either miR-145-5p or miR-203a-5p was able to sensitize the IR-K562 cells to imatinib. The concentration of key oncometabolites; glucose, lactate, and glutamine, in the culture media of the miR-transfected IR-K562 cells, reverted to the same levels as seen in imatinib-sensitive K562 cells. In addition, the FBA analysis revealed that the metabolism of lipid, fatty acids, and electron transport chain were significantly altered in resistant cells. The FBA data was also validated at the molecular level. Interestingly, the imatinib treatment coupled with the transfection of miR-145-5p or miR-203a-5p cells could reverse the metabolic flux of IR-K562 to the levels seen in imatinib-sensitive K562 cells. This study highlights the key metabolic changes that occur during development of imatinib resistance. It also identifies the specific miRNAs which can be targeted to overcome imatinib resistance in CML.

miR-145-5p and miR-203a-5p overcome imatinib resistance in myelogenous leukemic cells through metabolic reprogramming

Imatinib is the most effective therapy for chronic myeloid leukemia (CML), but many patients eventually develop resistance to it after an initial satisfactory response. This study investigated the potential of three miRNAs (miR-106b-5p, miR-145-5p, miR-203a-5p) in overcoming imatinib resistance in leukemic cells. The imatinib-resistant K562 (IR-K562) cells were developed and transfected with one of the three miRNAs to evaluate their potency in overcoming imatinib resistance. The changes in the metabolic profile were studied using flux balance analysis (FBA) and the data was validated using qRT-PCR.Among the three miRNAs, the ectopic expression of either miR-145-5p or miR-203a-5p was able to sensitize the IR-K562 cells to imatinib. The concentration of key oncometabolites; glucose, lactate, and glutamine, in the culture media of the miR-transfected IR-K562 cells, reverted to the same levels as seen in imatinib-sensitive K562 cells. In addition, the FBA analysis revealed that the metabolism of lipid, fatty acids, and electron transport chain were significantly altered in resistant cells. The FBA data was also validated at the molecular level. Interestingly, the imatinib treatment coupled with the transfection of miR-145-5p or miR-203a-5p cells could reverse the metabolic flux of IR-K562 to the levels seen in imatinib-sensitive K562 cells. This study highlights the key metabolic changes that occur during development of imatinib resistance. It also identifies the specific miRNAs which can be targeted to overcome imatinib resistance in CML.

Construction of human TCRP1 gene knockout chronic myeloid leukemia K562 cell line using CRISPR/Cas9 technology and its biological function detection / 中国医师杂志

Objective:To select human chronic myeloid leukemia (CML) cell line K562 as the experimental object, and use lentivirus mediated CRISPR/Cas9 gene editing technology to construct a stable CML cell line K562/TCRP1-KO that knocks out the tongue cancer resistance related protein 1 (TCRP1) gene; and through functional tests such as cell proliferation, apoptosis, and drug sensitivity, compare the phenotypic differences between K562/TCRP1-KO and control cells (K562/cas9-CTL), and preliminarily explore the possible mechanism of TCRP1 gene involvement in the pathogenesis of CML.Methods:The small guide RNA (sgRNA) targeting TCRP1 was designed at a specific location. After annealing, the oligonucleotide fragments were recombined with the linearized Cas9 expression vector, and the lentivirus packaging system was transfected into 293T cells. The purified virus was collected and infected with K562 cells. Positive polyclons were screened for puromycin pressure, and monoclonal K562/TCRP1-KO was further screened by limited dilution method. Stable cell lines were successfully knocked out by sanger sequencing and Western blot detection; Simultaneously, K562 cells transfected with lentiCRISPR vector were constructed as control cell lines (K562/cas9-CTL); Using cell counting method, cell counting kit 8 (CCK8) method, imatinib (IM) gradient dilution method, and flow cytometry cell proliferation, drug sensitivity, and apoptosis analysis were performed on K562/TCRP1-KO and K562/cas9-CTL, respectively.Results:The sgRNA-Cas9 recombinant plasmid vector for TCRP1 knockout was successfully constructed, and after transfection into 293T cells, TCRP1 knockout monoclonal cell lines were successfully screened using limited dilution method. Compared with K562/cas9-CTL cells, the proliferation ability of K562/TCRP1-KO cells was significantly reduced, IM drug sensitivity was significantly enhanced, and the process of cell apoptosis was significantly accelerated (all P<0.05). Conclusions:A CML cell line with TCRP1 knockout was successfully constructed using CRISPR/Cas9. TCRP1 may act as a cancer related gene to affect the proliferation, IM resistance, and apoptosis process of CML cells.

Effects of miR-144-3p on Proliferation, Cell Cycle and Apoptosis of K562 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of miR-144-3p on cell proliferation, cell cycle and apoptosis of blast phase chronic myelogenous leukemia (CML) K562 cells.@*METHODS@#K562 cells were cultured in vitro and mimics negative control, hsa-miR-144-3p mimics, inhibitor negative control and miR-144-3p inhibitor were respectively transfected into K562 cells with transfection reagents. The cells were divided into five groups including blank control, mimics negative control, miR-144-3p mimics, inhibitor negative control and miR-144-3p inhibitor. After transfection, the cell proliferation activity was detected by CCK-8 assay. The cell cycle distribution and apoptosis were detected by flow cytometry.@*RESULTS@#Compared with the blank control and mimics negative control groups, the proliferation rate of miR-144-3p mimics group was significantly decreased (P<0.05), the proportion of S phase cells was markedly increased (P<0.05), while the proportion of G1 phase cells was obviously decreased (P<0.05), and the apoptosis rate was significantly increased (P<0.05). Compared with the blank control and inhibitor negative control groups, the proliferation rate of miR-144-3p inhibitor group was obviously increased (P<0.05), the proportion of S phase cells was markedly decreased (P<0.05), while the proportion of G1 phase cells was obviously increased (P<0.05), and the apoptosis rate was significantly decreased (P<0.05).@*CONCLUSION@#miR-144-3p can inhibit the proliferation and promote apoptosis of K562 cells, affect the cell cycle, and block K562 cells in S phase, which indicates that miR-144-3p is involved in the cell cycle activity of CML during blastic phase.

Effect of Dichloromethane Extraction Phase of Patrinia Scabiosaefolia Fisch. Stem on Proliferation and Differentiation of K562 Cells / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of dichloromethane extraction phase of ethanol extract from stem of Patrinia scabiosaefolia Fisch.(DPSS) on proliferation and differentiation of K562 cells and its related mechanism.@*METHODS@#MTT assay was used to detect the effects of DPSS at 0, 25, 50, 100 and 200 μg/ml on the proliferation of K562 cells at 24, 48 and 72 hours. Flow cytometry was used to analyze the changes of cell cycle and apoptosis at 24 and 48 hours. Wright-Giemsa staining was used to observe the morphological changes of K562 cells. The cell surface antigens CD33 and CD11b were detected by flow cytometry.@*RESULTS@#The proliferation of K562 cells treated with different concentrations of DPSS was inhibited in a time-dose dependent manner (r=-0.96). Cell cycle analysis showed that with the increase of DPSS concentration, cells in G2/M phase increased (r=0.88), and cells were blocked in G2/M phase. Flow cytometry results showed that with the apoptosis rate of K562 cells was the highest when treated with 200 μg/ml DPSS for 48 h. Morphological observation showed that the K562 cell body increased, the amount of cytoplasm increased, the ratio of nucleus to cytoplasm decreased, and the nuclear chromatin was rough after DPSS treatment. Cell differentiation antigen, CD33 and CD11b, were positively expressed after treated with DPSS.@*CONCLUSION@#DPSS can induce apoptosis through cell cycle arrest, inhibit the proliferation of K562 cells, and induce K562 cells to differentiate into monocytes, which has a potential anti-leukemia effect.

Study on the Relationship between Integrin 2A and Drug Resistance in Chronic Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the expression pattern and clinical significance of Integral membrane protein 2A（ITM2A） in drug resistant patients with chronic myeloid leukemia (CML).@*METHODS@#The expression of ITM2A in CML was evaluated by qRT-PCR, Western blot and immunocytochemistry. In order to understand the possible biological effects of ITM2A, apoptosis, cell cycle and myeloid differentiation antigen expression of CML cells were detected by flow cytometry after over-expression of ITM2A. The nuderlying molecular mechanism of its biological effect was explored.@*RESULTS@#The expression of ITM2A in bone marrow of CML resistant patients was significantly lower than that of sensitive patients and healthy donors（P<0.05）. The CML resistant strain cell K562R was successfully constructed in vitro. The expression of ITM2A in the resistant strain was significantly lower than that in the sensitive strain(P<0.05). Overexpression of ITM2A in K562R cells increased the sensitivity of K562R cells to imatinib and blocked the cell cycle in G2 phase(P<0.05), but did not affect myeloid differentiation. Mechanistically, up-regulation of ITM2A reduced phosphorylation in ERK signaling (P<0.05).@*CONCLUSION@#The expression of ITM2A was low in patients with drug resistance of CML, and the low expression of ITM2A may be the key factor of imatinib resistance in CML.

Periplaneta americana extract CⅡ-3 induces senescence of leukemia K562 cells via SIRT1/mTOR signaling pathway / 中国中药杂志

This study aims to investigate the role of slient mating-type information regulation 2 homolog 1(SIRT1)/tuberous sclerosis complex 2(TSC2)/mammalian target of rapamycin(mTOR) signaling pathways in the Periplaneta americana extract CⅡ-3-induced senescence of human leukemia K562 cells. K562 cells were cultured in vitro and treated with 0(control), 5, 10, 20, 40, 80, and 160 μg·mL~(-1) of P. americana extract CⅡ-3. Cell counting kit-8(CCK-8) and flow cytometry were employed to examine the proliferation and cell cycle of the K562 cells. Senescence-associated β-galactosidase stain kit(SA-β-gal) was used to detect the positive rate of senescent cells. Mitochondrial membrane potential was detected by flow cytometry. The relative mRNA level of telomerase reverse transcriptase(TERT) was determined by fluorescence quantitative PCR. The mRNA and protein levels of SIRT1, TSC2, and mTOR were determined by fluorescence quantitative PCR and Western blot, respectively. The results showed that CⅡ-3 significantly inhibited the proliferation of K562 cells and the treatment with 80 μg·mL~(-1) CⅡ-3 for 72 h had the highest inhibition rate. Therefore, 80 μg·mL~(-1) CⅡ-3 treatment for 72 h was selected as the standard for subsequent experiments. Compared with the control group, CⅡ-3 increased the proportion of cells arrested in G_0/G_1 phase, decreased the proportion of cells in S phase, increased the positive rate of SA-β-Gal staining, elevated the mitochondrial membrane potential and down-regulated the mRNA expression of TERT. Furthermore, the mRNA expression of SIRT1 and TSC2 was down-regulated, while the mRNA expression of mTOR was up-regulated. The protein expression of SIRT1 and p-TSC2 was down-regulated, while the protein expression of p-mTOR was up-regulated. The results indicated that P. americana extract CⅡ-3 induced the senescence of K562 cells via the SIRT1/mTOR signaling pathway.

Citotoxicidad in vitro del polipéptido antimicrobiano nisina sobre células tumorales sanguíneas / In vitro cytotoxicity of the antimicrobial polypeptide nisin on blood tumor cells

RESUMEN: Las bacteriocinas son péptidos antimicrobianos de síntesis ribosomal secretadas por bacterias. Dentro de estas destaca nisina que posee potenciales usos en terapias antibióticas, como biopreservante de alimentos y probióticos. También se ha descrito que nisina posee citotoxicidad sobre líneas celulares neoplásicas, pero existe poca información de su efecto sobre células tumorales sanguíneas. Debido al potencial uso que presenta nisina, es relevante determinar la toxicidad que presenta sobre líneas celulares tumorales del tipo sanguíneo. Para esto, se realizaron ensayos de actividad hemolítica sobre eritrocitos humanos y de toxicidad sobre células mononucleares de sangre periférica humanas, determinándose que nisina no posee efecto citotóxico sobre este tipo de células normales humanas sanguíneas. Se realizaron también, ensayos de citotoxicidad con líneas celulares tumorales (K562 y U937), con el fin de determinar dosis, tiempo de exposición y selectividad en el efecto tóxico de nisina sobre las células tumorales humanas. Estos ensayos muestran que nisina presenta actividad citotóxica sobre líneas celulares K562 y U937 a las 72 h de exposición, a una concentración de 40 µg/mL, que corresponde a 100 veces la concentración mínima inhibitoria (MIC) usada para su acción sobre bacterias. Al comparar el efecto de nisina sobre células mononucleares de sangre periférica humanas con las líneas tumorales linfoides y mieloides (K562 y U937 respectivamente), se observa un efecto selectivo de nisina sobre las células tumorales sanguíneas.

SUMMARY: Bacteriocins are antimicrobial peptides of ribosomal synthesis secreted by bacteria. Among these, nisin stands out, which has potential uses in antibiotic therapies, as a food bio preservative and probiotics. Nisin has also been reported to have cytotoxicity on neoplastic cell lines, but there is little information on its effect on blood tumor cells. Due to the potential use that nisin presents, it is relevant to determine the toxicity it presents on tumor cell lines of the blood type. For this, hemolytic activity tests were carried out on human erythrocytes and toxicity on human peripheral blood mononuclear cells, determining that nisin does not have a toxic effect on this type of normal human blood cells. Cytotoxicity tests were also carried out with tumor cell lines (K562 and U937), to determine dose, exposure time and selectivity in the toxic effect of nisin on human tumor cells. These tests show that nisin shows cytotoxic activity on K562 and U937 cell lines at 72 h of exposure, at a concentration of 40 µg / mL, which corresponds to 100 times the minimum inhibitory concentration (MIC) used for its action on bacteria. When comparing the effect of nisin on human peripheral blood mononuclear cells with lymphoid and myeloid tumor lines (K562 and U937 respectively), a selective effect of nisin on blood tumor cells is observed.

Mechanism of berberine reverses drug resistance of K562/A02 cells by down-regulating protein kinase C-alpha / 国际中医中药杂志

Objective:To observe the effect of berberine on leukemia drug-resistant cell strain K562/A02 to Adriamycin resistance and protein kinase C-alpha (PRKCA) and explore its possible mechanism.Methods:The leukemia K562 cells of human chronic myeloid and Adriamycin resistant strain K562/A02 were cultured in vitro with 2.5-50.0 μmol/L doxorubicin to treat thoese cells and drug resistance of K562 and K562/A02 to Adriamycin was detected, the 50% inhibitory concentration (IC 50) of the drug was calculatedthe resistance of K562 and K562/A02 to doxorubicin was detectd , and, K562/A02 cells were treated with doxorubicin solution at a final concentration of 5 μmol/L, and K562/A02 cells were divided into control group, inhibitor group (50 μmol/L PRKCA inhibitor), low dose berberine group, medium dose berberine group and high dose berberine group. Cell counting (CCK-8) method was used to detect the inhibition rate of cell proliferation, the apoptosis was detected by flow cytometry, real-time fluorescent quantitative PCR assay detects PRKCA, MRP, multidrug resistance related genes (MDR1) levels, and the protein expressions of protein kinase C-α (PRKCA), multidrug resistance related protein (MRP), P-glycoprotein (P-gp) were detected by Western blotting. Results:The IC 50 concentration of K562/A02 to Adriamycin was significantly higher than K562. Compared with the control group, the inhibition rate of cell proliferation and the apoptosis rate in the inhibitor group, low-dose berberine group, medium-dose berberine group, and high-dose berberine group were significantly increased ( P<0.05), the expression of PRKCA mRNA (0.45±0.08, 0.92±0.10, 0.57±0.05, 0.35±0.04 vs. 1.00±0.12), MDR1 gene (0.73±0.08, 0.87±0.09, 0.65±0.07, 0.41±0.05 vs. 1.00±0.11) and PRKCA (0.59±0.09, 0.78±0.12, 0.61±0.11, 0.42±0.07 vs. 0.96±0.14), MRP (0.62±0.08, 0.79±0.13, 0.62±0.10, 0.41±0.06 vs. 0.98±0.14), P-gp (0.55±0.08, 0.75±0.12, 0.59±0.09, 0.35±0.06 vs. 0.92±0.15) were significantly reduced ( P<0.05), and berberine was dose-dependent ( P<0.05); Overexpression of PRKCA can inhibit the effect of berberine on reversing the drug resistance of K562/A02 cells. Conclusion:Berberine may reverse the drug resistance of K562/A02 to Adriamycin by down-regulating PRKCA.

The inhibition mechanism of ZST93 on proliferation of K562 through regulating cell cycle and apoptosis induced by autophagy / 中国药理学通报

Aim To evaluate the effect of ZST93 on the proliferation in human chronic myeloid leukemia(CML)cells(K562)and explore the possible mechanism.Methods MTT assay, cell growth curve and inverted microscope were used to investigate the effect of ZST93 on proliferation of K562 cells.Cell transfection and Western blot were performed to detect the autophagy, while PI staining, Annexin V-FITC/PI and flow cytometry were conducted to determine cell apoptosis and its anticancer mechanism.Results ZST93 could significantly inhibit the proliferation of K562(IC50=2.59 μmol·L-1)and induce cell cycle arrest at G1-phase in a dose- and time-dependent manner.Also, through leading to accumulation of GFP-LC3, transition into LC3- II from LC3- 1 , and decrease of p62 expression, ZST93 induced autophagy initiation and autophagic flux.Furthermore, ZST93 induced extrinsic apoptotic pathway by activating caspase-8, and further promoted the cleavage of apoptosis related proteins including caspase-9, caspase-3 and PAR P.Moreover, Z-DEYD-FMK, the specific inhibitor of caspase-3 , could dramatically reduce the apoptosis induced by ZST93.Taken together, ZST93 could effec tively inhibit CML cells, arrest eell cycle at G,-phase, induce cell apoptosis anrl initiate autophagy.Conclusions The potential mechanism may he related to the regulation of autophagy intiation/caspase-8/caspase-3 signaling pathway, which provides a new idea and theoretical basis for the treatment of CML.

Effects of Bacillus firmus e volumine ex muris cellulae 6x on cytolytic activity of natural killer cells in vitro

Natural killer (NK) cells are among the first in defense of the innate immune system by eliminating a variety of abnormal or stressed cells such as cancer cells or virus-infected cells. Individuals who exhibit low cytolytic NK cell activity are believed to be at higher risk of viral infection, tumorigenesis, and various other diseases of the immune system. Therefore, restoration of impaired NK cell function might be an essential step in immunostimulatory therapy of immunocompromised patients. Bacillus firmus is a non-pathogenic gram-positive bacterium of the environment, which possesses various immunomodulatory properties in vitro and in vivo. This retrospective study reports on the effect of B. firmus on the activity of NK cells in vitro. Basal cytolytic NK cell activity against tumor cells among peripheral blood mononuclear cells (PBMCs) of routine patients was determined in a standardized NK cell cytotoxicity assay. The impact of cultivation of PBMCs with B. firmus preparation Bacillus firmus e volumine ex muris cellulae (Bacillus firmus (evc)) 6x on tumor cell killing by NK cells was monitored in relation to basal NK cell activity. This study showed that stimulation of PBMCs with Bacillus firmus (evc) 6x in vitro led to a significant increase in NK cell function. Substantial improvement in cytolytic NK cell activity (more than 1.3-fold of basal activity) was much more pronounced for patients with compromised NK cell function. Due to its immunostimulatory mode of action, Bacillus firmus (evc) may be of particular importance in therapy of patients with NK cell deficiency.

Tanshinone I inhibited growth of human chronic myeloid leukemia cells via JNK/ERK mediated apoptotic pathways

Tanshinone I (Tan I) is one of the main bioactive ingredients derived from Salvia miltiorrhiza Bunge, which has exhibited antitumor activities toward various human cancer cells. However, its effects and underlying mechanisms on human chronic myeloid leukemia (CML) cells still require further investigation. This study determined the effects and mechanisms of anti-proliferative and apoptosis induction activity induced by Tan I against K562 cells. The cytotoxic effect of Tan I at varying concentrations on K562 cells was evaluated via MTT assay. Cell apoptosis was further investigated through DAPI staining and flow cytometry analysis. The expression levels of apoptosis-related proteins and activities of JNK/ATF2 and ERK signaling pathways were analyzed by western blot. Quantitative PCR was performed to further determine mRNA expression levels of JNK1/2 and ERK1/2 after Tan I treatment. The results indicated that Tan I significantly inhibited K562 cell growth and induced apoptosis in a concentration- and time-dependent manner. It induced significant cellular morphological changes and increased apoptosis rates in CML cells. Tan I promoted the cleavages of caspase-related proteins, as well as increased the expression levels of PUMA. Furthermore, Tan I significantly activated JNK and inhibited ATF-2 and ERK signaling pathways. The mRNA expression levels of JNK1/2 and ERK1/2 were up-regulated by Tan I, further confirming its regulatory effects on JNK/ERK signaling pathways. Overall, our results indicated that Tan I suppressed cell viability via JNK- and ERK-mediated apoptotic pathways in K562 cells, suggesting that it might be a promising candidate as a novel anti-leukemia drug.

Preclinical study of suicide gene as a safety switch to control CAR-T cell cytotoxicity / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate whether AP1903, a small-molecule chemical inducer, can terminate the cytotoxicity of CD19CAR-T cells over-expressing iCasp9 suicide gene in vivo and in vitro. Methods: CD19CAR-T cells over-expressing iCasp9 (iCasp9-CD19CAR-T) were constructed and co-incubated with AP1903. Then, the cell phenotype and apoptosis were detected by Flow cytometry, and the iCasp9/CID suicide gene system was verified on K562 and T cells, respectively. The cytotoxicity of iCasp9-CD19CAR-T cells was detected in vivo (survival rate of NCG mice bearing Raji cell transplanted xenograft) and in vitro (cell killing function was detected by Flow cytometry) under the administration of AP1903. Results: Compared with CD19CAR-T cells, iCasp9-CD19CAR-T cells showed in significant difference in proliferation, phenotype and cytotoxicity both in vitro and in vivo (all P>0.05). At 2 h after AP1903 administration, the apoptosis rates of K562 and T cells co-expressing iCasp9 and CD19CAR were (33.8±0.9)% and (27.95±0.35)%, respectively; and at 24 h after AP1903 administration, the apoptosis rates reached 100% in both cell lines. The in vitro cytotoxicity of iCasp9-CD19CAR-T cells induced by AP1903 was significantly lower than that without AP1903 treatment (P<0.01); the 60-day survival rate of mice bearing Raji cell transplanted tumor treated with AP1903-induced iCasp9-CD19CAR-T cells was also significantly lower than those treated with iCasp9-CD19CAR-T cells alone (P<0.01). Conclusion: AP1903 can effectively terminate the cytotoxicity of CD19CAR-T cells over-expressing iCasp9 suicide gene in vitro and in vivo.

Germacranolide sesquiterpenes from Carpesium cernuum and their anti-leukemia activity / 中国天然药物

In this study, three new germacranolide sesquiterpenes (1-3), together with six related known analogues (4-9) were isolated from the whole plant of Carpesium cernuum. Their structures were established by a combination of extensive NMR spectroscopic analysis, HR-ESIMS data, and ECD calculations. The anti-leukemia activities of all compounds towards three cell lines (HEL, KG-1a, and K562) were evaluated in vitro. Compounds 1-3 exhibited moderate cytotoxicity with IC

Study on relationship between autophagy and drug resistance of leukemia K562/ADM cells / 中国药理学通报

Aim To set up leukemic K562/ADM cells with stable tolerance to 15 fimol • L_1 ADM induced in vitro by long-term and continuous stepwise increment of adriamycin (ADM) concentration, to observe the sensitivity to other chemotherapy drugs and the relationship between autophagy and drug resistance.Methods MTT assay was used to detect the sensitivity of cells to chemotherapy drugs.The morphological changes of autophagy were observed by transmission electron microscope and fluorescence microscopy.Cell apoptosis analysis was performed using Annexin-V/PI double staining and flow cytometry ( FCM ).The expressions of autophagy and drug resistance associated proteins were tested by Western blot.Results K562/ADM cells were cross-resistance to the other chemotherapeu-tics besides adriamyciri, such as pirarubicin, daunoru- bicin, 5-flurouracil, vincristine but not arsenic triox- ide.The number of autophagosomes, the fluorescence intensity of monodansylcadaverine (MDC) and the expression of LC3-H ,Beclin-l in K562/ADM cells were significantly higher than those in K562 cells.The inhibition of autophagy by 3-MA significantly increased the sensitivity of K562/ADM cells to ADM, and 3-MA also effectively inhibited the expressions of drug resistance related proteins P-gp, MRP1 and BCRP in K562/ADM cells.Conclusions The K562/ADM cells resistant to adriamycin occur multidrug resistance, and the drug resistanceis closely related to the level of autophagy.

Evodiamine induces apoptosis of leukemia cell line K562 VIA modulation of TRIB2/AKT pathway / 中国药理学通报

Aim To investigate the effects of Evodiamine (EVO) on proliferation and apoptosis of human leukemia cell line K562 and its potential mechanisms. Methods K562 cells were treated with EVO at different concentrations (0, 1, 2, 4, 8, 16, 32, 64 jxmol • L

Kaempferol in reversing drug resistance of chronic myelogenous leukemia K562/ADM cells and its related mechanism / 白血病·淋巴瘤

Objective@#To investigate the drug resistance of kaempferol reversed adriamycin (ADM)-resistant K562/ADM cells in chronic myelogenous leukemia (CML) and its related mechanism.@*Methods@#Methyl thiazolyl tetrazolium (MTT) method was used to detect the toxicity of ADM on K562 and K562/ADM cells for 24 h. The half inhibitory concentration (IC50) of ADM and the drug resistance multiple for 24 h were calculated. MTT method was used to detect the toxicity of kaempferol on K562/ADM cells for 24 h. The 5% inhibitory concentration (IC5) and 10% inhibitory concentration (IC10) of kaempferol for 24 h were calculated to determine the concentration of kaempferol in the subsequent experiments. And the cells untreated by the kaempferol were selected as the control group. The cell inhibition after the treatment of ADM for 24 h of the blank control group and kaempferol intervention group was detected by using MTT method. And then the cell inhibition for 24 h and ADM IC50 for 24 h in the above groups were calculated. The ratio of IC50 in the blank control group and kaempferol group was the reversal drug resistance multiple of kaempferol. The fluorescence intensity of ADM in K562/ADM cells treated by kaempferol was detected by using flow cytometry. Western blotting was used to detect the expressions of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), phosphorylated p38 (p-p38), and total p38 (t-p38) protein in K562/ADM cells after the treatment of kaempferol, the specific inhibitor of p38-MAPK signaling pathway SB202190, and the combination of kaempferol and SB202190.@*Results@#After the treatment of ADM for 24 h, the IC50 value of K562 and K562/ADM cells was (0.9±0.6), (28.1 ±3.5) μg/ml, respectively. The drug resistance multiple of K562/ADM cells on the treatment of ADM for 24 h was 31.16 compared with the K562 cells. MTT method showed that kaempferol inhibited the proliferation of K562/ADM cells in a dose-dependent manner. According to the IC5 and IC10, 0.5 μmol/L and 1.0 μmol/L kaempferol were determined to do the subsequent experiments. After the combined interaction of kaempferol and ADM for 24 h, the ADM IC50 of K562/ADM cells in the blank control group, 0.5 μmol/L kaempferol group and 1.0 μmol/L kaempferol group was (33.7±5.7), (21.4±0.6), (15.9±1.8) μg/ml, respectively (F = 30.85, P < 0.05), and there was a statistical difference of pairwise comparison (both P < 0.05). The reversal drug resistance multiple of K562/ADM cells for 24 h in 0.5 μmol/L kaempferol group and 1.0 μmol/L kaempferol group was 1.58 and 2.12, respectively. Flow cytometry results showed that the mean fluorescence intensity (MFI) of ADM in the blank control group, 0.5 μmol/L kaempferol group and 1.0 μmol/L kaempferol group was 138.4±8.9, 154.3±2.2, 165.7±4.8, respectively, and the difference was statistically significant (F = 161.48, P < 0.05). Compared with the blank control group, after treatment of K562/ADM cells with 0.5 μmol/L and 1.0 μmol/L kaempferol for 24 h, the relative expressions of P-gp, MRP1 and p-p38 protein were decreased in K562/ADM cells (all P < 0.05), but there was no statistical difference in the expression of t-p38 protein (P > 0.05); SB202190 could reduce the relative expressions of P-gp, MRP1 and p-p38 protein (all P < 0.05); after the treatment of SB202190 combined with different concentration of kaempferol, the relative expressions of P-gp, MRP1 and p-p38 protein in K562/ADM cells did not decrease (P > 0.05).@*Conclusions@#Kaempferol can decrease the relative expressions of P-gp and MRP1 in K562/ADM cells by inhibiting p38-MAPK pathway, so as to increase the concentrations of ADM and to reverse the drug resistance of K562/ADM cells.