长春新碱通过下调SODD蛋白表达诱导白血病细胞凋亡新机制研究

 目的研究死亡结构域沉默子(silencer of death domains,SODD)、caspase3、caspase8及caspase9在长春新碱诱导Jurkat白血病细胞凋亡过程中的变化,探讨长春新碱诱导肿瘤细胞凋亡的新机制。方法采用Annexin V/PI双标记流式细胞术检测长春新碱(VCR)作用后Jurkat细胞凋亡发生率;采用免疫印迹法分析SODD、caspase3、caspase8及caspase9蛋白表达的变化;ELISA酶联免疫吸附技术检测VCR作用Jurkat细胞后TNF-α分泌的变化;采用RT-PCR检测VCR对细胞,TNFR1mRNA表达的调节。结果Jurkat白血病细胞SODD蛋白高表达且高表达的SODD蛋白抑制肿瘤细胞凋亡,VCR能特异下调SODD蛋白的表达,有效诱导Jurkat细胞凋亡,但并不影响细胞TNF-α的分泌及TNFR1的表达;VCR诱导细胞凋亡过程中caspase3、caspase8酶原呈时间依赖性逐渐被水解剪切,而caspase9在该凋亡过程中无明显变化趋势。结论VCR下调SODD蛋白表达并启动外源性凋亡途径caspases级联(caspase8、caspase3),最终诱导Jurkat细胞凋亡,且VCR下调SODD蛋白的表达无需激活TNF/TNFR1信号途径即可导致凋亡的发生。     

Chebulinic Acid Isolated From the Fruits of Terminalia chebula Specifically Induces Apoptosis in Acute Myeloid Leukemia Cells

Chebulinic acid, an ellagitannin found in the fruits of Terminalia chebula, has been extensively used in traditional Indian system of medicine. It has shown to have various biological activities including antitumor activity. The present study aims to investigate the cytotoxic potential of chebulinic acid in human myeloid leukemia cells. Interestingly, chebulinic acid caused apoptosis of acute promyelocytic leukemia HL‐60 and NB4 cells but not K562 cells. In vitro antitumor effects of chebulinic acid were investigated by using various acute myeloid leukemia cell lines. Chebulinic acid treatment to HL‐60 and NB4 cells induced caspase activation, cleavage of poly(ADP‐ribose) polymerase, DNA fragmentation, chromatin condensation, and changes in the mitochondrial membrane permeability. Additionally, inhibition of caspase activation drastically reduced the chebulinic acid‐induced apoptosis of acute promyelocytic leukemia cells. Our data also demonstrate that chebulinic acid‐induced apoptosis in HL‐60 and NB4 cells involves activation of extracellular signal‐regulated kinases, which, when inhibited with ERK inhibitor PD98059, mitigates the chebulinic acid‐induced apoptosis. Taken together, our findings exhibit the selective potentiation of chebulinic acid‐induced apoptosis in acute promyelocytic leukemia cells. Copyright © 2017 John Wiley & Sons, Ltd.     

Paris saponin VII induces cell cycle arrest and apoptosis by regulating Akt/MAPK pathway and inhibition of P‐glycoprotein in K562/ADR cells

Paris saponinVII (PSVII) is a steroidal saponin isolated from the roots and rhizomes of Trillium tschonoskii Maxim. We found that PSVII could inhibit the growth of adriamycin‐resistant human leukemia cells (K562/ADR) in a dose‐dependent manner. Furthermore, the molecular mechanism underlying the cytotoxicity and downregulation of P‐glycoprotein (P‐gp) expression by PSVII was clarified. PSVII significantly suppressed cell proliferation by cell cycle arrest in the G0/G1 phase, which was associated with an obvious decrease in cyclin B1/D1 and CDK2/4/6 protein expression. Moreover, PSVII could attenuate mitochondrial membrane potential, increase the expression of apoptosis‐related proteins, such as Bax and cytochrome c, and decrease the protein expression levels of Bcl‐2, caspase‐9, caspase‐3, PARP‐1, and p‐Akt. We also found that JNK, ERK1/2, and p38 were regulated by PSVII in K562/ADR cells. And further studies indicated that the decrease in the reactive oxygen species level inhibited intrinsic P‐gp expression. Therefore, PSVII‐induced apoptosis in K562/ADR cells was associated with Akt/MAPK and the inhibition of P‐gp. In addition, PSVII induced a robust autophagy in K562/ADR cells as demonstrated by the degradation of LC3‐I. These results provide a biochemical basis for possible clinical applications of PSVII in the treatment of leukemia.     

Induction of apoptosis in human acute leukemia Jurkat T cells by Albizzia julibrissin extract is mediated via mitochondria-dependent caspase-3 activation

To understand antitumor activity of Albizzia julibrissin Durazz (Leguminosae), which has been used as a traditional oriental medicine, the mechanism underlying cytotoxic effect of its extract on human acute leukemia Jurkat T cells were investigated. The methanol extract of the stripped barks (3kg) of Albizzia julibrissin was evaporated, dissolved in water, and then sequentially extracted by chloroform, ethyl acetate, and n-butanol. The substance in the butanol extract containing the most cytotoxic activity was further purified by a series of preparative column chromatography. The active substance obtained (723mg) was designated as HaBC18. When Jurkat T cells were treated with HaBC18 (0.5-2microg/ml), apoptosis along with several biochemical events such as mitochondrial cytochrome c release, activation of caspase-9 and -3, degradation of PARP, and DNA fragmentation was induced in a dose-dependent manner. However, the HaBC18-induced apoptosis was abrogated by an ectopic overexpression of Bcl-xL, which is known to block mitochondrial cytochrome c release. Primary cultures of human PBMC were less sensitive to the cytotoxicity relative to Jurkat T cells. These results demonstrate that the cytotoxicity of HaBC18 toward Jurkat T cells is attributable to apoptosis mediated by mitochondria-dependent death-signaling pathway regulated by Bcl-xL.     

Escin sodium induces apoptosis of human acute leukemia Jurkat T cells

Escin sodium has been used in the clinic as an antioedematous, antiexudative and vasoprotective agent for many years and has shown excellent tolerability. However, little is known about its anticancer activity. This is a report for the first time that escin sodium exerts a cytotoxic effect on human acute leukemia Jurkat T cells via the induction of apoptosis rather than cell cycle arrest. Escin sodium activated the initiator caspase-8, -9, and the effector caspase-3, degraded poly (ADP-ribose) polymerase (PARP) and attenuated the expression of Bcl-2. In addition, escin sodium inhibited the growth of cancer cells in a selective manner with Jurkat cells most sensitive to it. Taken together, the data show that escin sodium possesses potent apoptogenic activity toward human acute leukemia Jurkat T cells.     

Cytotoxic effect of mistletoe (Viscum album L.) extract on Jurkat cells and its interaction with doxorubicin

Mistletoe preparations are frequently used by cancer patients because of their ability to stimulate the immunity and to improve the quality of life. Moreover mistletoe and its active substances (especially lectins) possess cytotoxic effect on various cancer cell lines. However, only little is known about its interaction with anticancer drugs. Therefore the cytotoxic and apoptosis‐inducing effects of aqueous mistletoe extract (VA) and its interaction with doxorubicin (DOXO) were investigated in Jurkat cells. The results show that VA extract as well as DOXO exert cytotoxic effects on Jurkat cells in a dose‐dependent manner. Cytotoxicity of DOXO was much stronger (LC₅₀ = 11.68 ng/mL) than that of VA extract (LC₅₀ = 35.67 μg/mL). Their combination led to synergism only at those concentrations that were highly cytotoxic alone. Both substances (alone and in combination) induced DNA fragmentation in Jurkat cells. In conclusion, an aqueous extract prepared from mistletoe tops exerted cytotoxic and apoptosis‐inducing effects on Jurkat cells alone as well as in combination with DOXO. Copyright © 2009 John Wiley & Sons, Ltd.     

Apoptogenic activity of 2α,3α-dihydroxyurs-12-ene-28-oic acid from Prunella vulgaris var. lilacina is mediated via mitochondria-dependent activation of caspase cascade regulated by Bcl-2 in human acute leukemia Jurkat T cells

Ethnopharmacological relevance

The dried spikes of Prunella vulgaris var. lilacina (Labiatae) have been used for traditional herbal medicine to treat fever, inflammation, dropsy, gonorrhea and cancer in Korea, Japan and China. The present study evaluated the apoptotic effect of 2α,3α-dihydroxyurs-12-en-28-oic acid (DHURS), purified from the dried spikes on human acute leukemia Jurkat T cells.

Materials and methods

Cell viability was assessed by MTT assay. Mitochondrial membrane potential (Δψm) loss, apoptotic change of the cell cycle, and apoptotic cells were measured by flow cytometric analysis. Mitochondrial cytochrome c release and activation of caspase cascade were determined by Western blot analysis. Caspase-12 activity and caspase-3 activity were assayed using the Fluorometric Assay Kit and the Colorimetric Assay Kit, respectively.

Results

Treatment of Jurkat T cells with DHURS (20-25 μg/ml) caused cytotoxicity and apoptotic DNA fragmentation along with Δψm loss, mitochondrial cytochrome c release, activation of caspase-9, -7, -3, and -8, and PARP degradation. However, these apoptotic events were abrogated by overexpression of Bcl-2. Pretreatment of the cells with the pan-caspase inhibitor (z-VAD-fmk), the caspase-9 inhibitor (z-LEHD-fmk) or the caspase-3 inhibitor (z-DEVD-fmk) to prevent DHURS-induced apoptosis could block the activation of caspase-7 and -8, and PARP degradation, but not the Δψm loss, activation of caspase-9 and -3. Both FADD- and caspase-8-positive wild-type Jurkat clone A3, FADD-deficient Jurkat clone I2.1, and caspase-8-deficient Jurkat clone I9.2 exhibited similar susceptibilities to the cytotoxicity of DHURS, excluding an involvement of Fas/FasL system in triggering the apoptosis. The IC₅₀ value for Jurkat T cells was ∼22 μg/ml, whereas that for human peripheral T cells was 25 μg/ml.

Conclusions

These results indicate that DHURS-induced apoptogenic activity in Jurkat T cells, which was less potent in normal peripheral T cells, was mediated by Δψm loss, mitochondrial cytochrome c release, and subsequent activation of caspase-9 and -3, leading to activation of caspase-7 and -8, which could be regulated by Bcl-2.     

新型磷脂酰肌醇-3激酶δ抑制剂idelalisib

磷脂酰肌醇-3激酶（PI3K）是一种胞内磷脂酰肌醇激酶,吉利德正在开发的血癌新药idelalisib是首个选择性口服PI3K抑制剂,与α、β、γ亚基相比,其可高度选择性地作用于δ亚基。idelalisib可阻滞PI3Kδ-Akt信号通路并促进细胞凋亡,从而有效治疗难治性惰性非霍奇金淋巴瘤（iNHL）。研究表明idelalisib能够显著增加B细胞急性淋巴细胞白血病（B-ALL）和慢性淋巴细胞白血病（CLL）细胞系的凋亡,同时没有显著增加正常T细胞的凋亡。在一系列临床研究中显示出良好的治疗前景,且安全性及耐受性均较好。     

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??OBJECTIVE To study the anti-leukemia activities and mechanisms of bergenin derivative D-23. METHODS CCK-8 method was applied to investigate anti-tumor activities of D-23. Flow cytometry and immunofluorescence assay were used to observe the effects of D-23 on the apoptosis and autophagy in K562 and Jurkat human leukemia cell lines. Western blot analysis was used to investigate the mechanisms that compound D-23 induced tumor cell apoptosis and autophagy. RESULTS Bergenin derivative D-23 could significantly inhibit the proliferation of K562 and Jurkat cells by inducing cell apoptosis and autophagy. The mitochondrial membrane potential was decreased,protein kinase B(Akt)and heat shock protein 70 (Hsp70) were inhibited,and the expressions of apoptotic related proteins caspase 3 and caspase 9 were activated. In addition, mammalian target of rapamycin (P-mTOR)(Ser 2448 and Ser 2481)protein was inhibited. CONCLUSION Bergenin derivative D-23 shows obvious anti-leukemia activities by inducing cell apoptosis and autophagy. The apoptosis may be associated with the reduction of mitochondrial membrane potential and activation of caspase pathway. The autophagy may be related to the inhibition of Akt/mTOR signaling pathway.     

Nobiletin,a Polymethoxylated Flavone,Inhibits Glioma Cell Growth and Migration via Arresting Cell Cycle and Suppressing MAPK and Akt Pathways

Nobiletin, a bioactive polymethoxylated flavone (5,6,7,8,3^',4^'‐hexamethoxyflavone), is abundant in citrus fruit peel. Although nobiletin exhibits antitumor activity against various cancer cells, the effect of nobiletin on glioma cells remains unclear. The aim of this study was to determine the effects of nobiletin on the human U87 and Hs683 glioma cell lines. Treating glioma cells with nobiletin (20–100 µm ) reduced cell viability and arrested the cell cycle in the G0/G1 phase, as detected using a 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay and propidium iodide (PI) staining, respectively; however, nobiletin did not induce cell apoptosis according to PI‐annexin V double staining. Data from western blotting showed that nobiletin significantly attenuated the expression of cyclin D1, cyclin‐dependent kinase 2, cyclin‐dependent kinase 4, and E2 promoter‐binding factor 1 (E2F1) and the phosphorylation of Akt/protein kinase B and mitogen‐activated protein kinases, including p38, extracellular signal‐regulated kinase, and c‐Jun N‐terminal kinase. Our data also showed that nobiletin inhibited glioma cell migration, as detected by both functional wound healing and transwell migration assays. Altogether, the present results suggest that nobiletin inhibits mitogen‐activated protein kinase and Akt/protein kinase B pathways and downregulates positive regulators of the cell cycle, leading to subsequent suppression of glioma cell proliferation and migration. Our findings evidence that nobiletin may have potential for treating glioblastoma multiforme. Copyright © 2015 John Wiley & Sons, Ltd.     

油茶皂苷通过内质网应激途径诱导Jurkat细胞凋亡的研究

目的探讨油茶皂苷在体外诱导人白血病细胞Jurkat凋亡的作用及作用机制。方法将1～4μg/mL的油茶皂苷作用于人白血病Jurkat细胞,应用细胞计数考察油茶皂苷对细胞增殖的影响;用Western blot方法分析油茶皂苷对caspase-3、PARP、Bipc、hop、Perk、ATF6和IRE1蛋白表达的影响。结果油茶皂苷(1～4μg/mL)对Jurkat细胞的增殖产生明显的剂量依赖性抑制作用。免疫印迹结果显示,油茶皂苷可以使caspase-3激活,增加Cleaved PARP的表达量,而诱导Jurkat细胞发生凋亡;其作用机制是通过下调Bip和chop的表达,触发Perk、ATF6和IRE1 3个内质网应激跨膜蛋白而产生细胞凋亡的。结论 1～4μg/mL油茶皂苷具有抑制人白血病细胞增殖和诱导其凋亡的作用,其作用机制参与了细胞凋亡的内质网应激途径。     

[6]‐Gingerol enhances the cisplatin sensitivity of gastric cancer cells through inhibition of proliferation and invasion via PI3K/AKT signaling pathway

Cisplatin‐based chemotherapy is a widely used chemotherapeutic regimen for gastric cancer; however, drug resistance limits its efficacy. [6]‐Gingerol has been found to exhibit anticancer effects. Here, we aim to explore the potential of [6]‐gingerol in combination with cisplatin as a new regimen for gastric cancer. CCK‐8 assay and colony formation assay were used to determine the effect of [6]‐gingerol in combination with cisplatin on cell viability of gastric cancer cells. Flow cytometry was performed to assess cell cycle distribution. Wound‐healing assay and transwell invasion assay were conducted to examine the migration and invasion abilities. Cell cycle and invasion‐related proteins and mRNAs, as well as PI3K/AKT signaling proteins, were assessed by western blotting and quantitative real‐time polymerase chain reaction. Combination of [6]‐gingerol with cisplatin inhibited cell viability and enhanced cell cycle arrest at G1 phase compared with cisplatin alone. The combination treatment inhibited cell migration and invasion ability and decreased cyclin D1, cyclin A2, matrix metalloproteinase‐9, p‐PI3K, AKT, and p‐AKT protein expressions and increased P21 and P27 mRNA levels. Our study demonstrates that [6]‐gingerol enhances the cisplatin sensitivity of gastric cancer cells and that the mechanisms involve G1 phase arrest, migration and invasion suppression via PI3K/AKT signaling pathway.     

Gossypin inhibits gastric cancer growth by direct targeting of AURKA and RSK2

Gossypin is a flavone extracted from Hibiscus vitifolius, which has been reported to exhibit anti‐inflammatory, antioxidant, and anticancer activities. However, the anticancer properties of gossypin and its molecular mechanism of action against gastric cancer have not been fully investigated. In the present study, we report that gossypin is an Aurora kinase A (AURKA) and RSK2 inhibitor that suppresses gastric cancer growth. Gossypin attenuated anchorage‐dependent and anchorage‐independent gastric cancer cell growth as well as cell migration. Based on the results of in vitro screening and cell‐based assays, gossypin directly binds to and inhibits AURKA and RSK2 activities and their downstream signaling proteins. Gossypin decreased S phase and increased G2/M phase cell cycle arrest by reducing the expression of cyclin A2 and cyclin B1 and the phosphorylation of the CDC protein. Additionally, gossypin also induced intrinsic apoptosis by activating caspases and PARP and increasing the expression of cytochrome c. Our results demonstrate that gossypin is an AURKA and RSK2 inhibitor that could be useful for treating gastric cancer.     

七叶皂苷钠抑制人白血病Jurkat细胞增殖的机制研究

目的研究七叶皂苷钠抑制人白血病Jurkat细胞增殖的作用及其机制。方法 MTT法分析七叶皂苷钠对Jurkat细胞增殖的抑制作用,Hoechst 33258染色、FITC-Annexin V/PI双染、DNA Ladder、流式细胞术检测细胞凋亡和细胞周期,Western blotting法分析凋亡相关蛋白变化。结果七叶皂苷钠呈质量浓度和时间相关方式抑制Jurkat细胞增殖;经七叶皂苷钠处理后的Jurkat细胞出现凋亡的形态学特征、DNA条带,Annexin V+/PI细胞(早期凋亡细胞)显著增加;七叶皂苷钠可活化Jurkat细胞中Caspase-8、Caspase-9、Caspase-3,引起PARP的切割,并减少Bcl-2蛋白的表达。结论七叶皂苷钠能有效地通过诱导细胞凋亡抑制Jurkat细胞增殖。     

Berberine inhibits SREBP‐1‐related clozapine and risperidone induced adipogenesis in 3T3‐L1 cells

Weight gain is a common and potentially serious complication associated with the treatment of second generation antipsychotics such as clozapine and risperidone. Increased peripheral adipogenesis via the SREBP‐1 pathway could be one critical mechanism responsible for antipsychotic drug‐induced weight gain. Berberine, a botanic alkaloid, has been shown in our previous studies to inhibit adipogenesis in cell and animal models. MTT was used to determine the cytotoxic effects of clozapine and risperidone in combination with berberine. Differentiation of 3T3‐L1 cells was monitored by Oil‐Red‐O staining and the expression of SREBP‐1 and related proteins was determined by real‐time RT‐PCR and western blotting. The results showed that neither clozapine nor risperidone, alone or in combination with berberine had significant effects on cell viability. Eight days treatment with 15 μm clozapine increased adipogenesis by 37.4% and 50 μm risperidone increased adipogenesis by 26.5% during 3T3‐L1 cell differentiation accompanied by increased SREBP‐1, PPARγ, C/EBPα, LDLR and Adiponectin gene expression. More importantly, the addition of 8 μm berberine diminished the induction of adipogenesis almost completely accompanied by down‐regulated mRNA and protein expression levels of SREBP‐1‐related proteins. These encouraging results may lead to the use of berberine as an adjuvant to prevent weight gain during second generation antipsychotic medication. Copyright © 2010 John Wiley & Sons, Ltd.     

小檗碱增强K562/DOX细胞对多柔比星敏感性的研究

 目的 探讨小檗碱增强耐药K562/DOX细胞对化疗药多柔比星的敏感性的作用。方法 四甲基偶氮唑蓝法检测小檗碱的细胞毒性及其对多柔比星抗肿瘤活性的增强作用;高内涵活细胞成像系统检测无毒剂量小檗碱作用后,多柔比星在K562/DOX细胞内的蓄积量;PI/Hoechst33342双染法检测小檗碱对多柔比星诱导的K562/DOX细胞凋亡的影响;罗丹明123蓄积实验检测小檗碱对P-糖蛋白外排功能的影响。结果 1 μmol·L^-1为小檗碱的无毒剂量,在此无毒剂量下,小檗碱使多柔比星对K562/DOX细胞的IC₅₀降低了1.5倍;1 μmol·L^-1小檗碱可使多柔比星在K562/DOX细胞内的蓄积量增加,增强多柔比星诱导的K562/DOX细胞凋亡, 增加K562/DOX细胞内罗丹明123的蓄积量,从而抑制P-糖蛋白的外排功能。结论 小檗碱可通过抑制K562/DOX细胞膜上P-糖蛋白的外排功能,增加K562/DOX细胞内多柔比星浓度,促进多柔比星对耐药细胞的诱导凋亡作用,逆转K562/DOX细胞的多药耐药性。     

Korean Red Ginseng Extract Enhances the Anticancer Effects of Sorafenib through Abrogation of CREB and c‐Jun Activation in Renal Cell Carcinoma

Although application of sorafenib in the treatment of human renal cell carcinoma (RCC) remains one of the best examples of successful targeted therapy, majority of RCC patients suffer from its side effects as well as develop resistance to this targeted therapy. Thus, there is a need to promote novel alternative therapies for the treatment of RCC. In this study, we investigated whether Korean red ginseng extract (KRGE) could inhibit the proliferation and induce chemosensitization in human renal cancer cells. Also, we used a human phospho‐antibody array containing 46 antibodies against signaling molecules to examine a subset of phosphorylation events after KRGE and sorafenib combination treatment. Korean red ginseng extract suppressed the proliferation of two RCC cell lines; activated caspase‐3; caused poly(ADP‐ribose) polymerase cleavage; abrogated the expression of B‐cell lymphoma 2, B‐cell lymphoma extra large, survivin, inhibitors of apoptosis proteins‐1/2, cyclooxygenase‐2, cyclin D1, matrix metallopeptidase‐9, and vascular endothelial growth factor; and upregulated pro‐apoptotic gene products. Interestingly, KRGE enhanced the cytotoxic and apoptotic effects of sorafenib in RCC cells. The combination treatment of KRGE and sorafenib more clearly suppressed cyclic adenosine monophosphate response element‐binding protein and c‐Jun phosphorylation and induced phosphorylation of p53 than did the individual treatment regimen. Our results clearly demonstrate that KRGE can enhance the anticancer activity of sorafenib and may have a substantial potential in the treatment of RCC. Copyright © 2017 John Wiley & Sons, Ltd.     

Berberine ameliorates lipopolysaccharide‐induced acute lung injury via the PERK‐mediated Nrf2/HO‐1 signaling axis

A fundamental element of acute lung injury (ALI) is the inflammatory response, which can affect the entire respiratory system, including the respiratory tract and alveoli. Berberine has gained attention because of its anti‐inflammatory effects. Nuclear factor‐erythroid 2‐related factor 2 (Nrf2) and endoplasmic reticulum (ER) stress are involved in lung injury. Nrf2 also acts as a protein kinase‐like ER kinase (PERK) substrate in heart disease. Therefore, this study investigated the effect of berberine against lipopolysaccharide (LPS)‐induced ALI and the role of the PERK‐mediated Nrf2/HO‐1 signaling axis. Berberine promoted Nrf2 nuclear translocation and phosphorylation in vitro. After LPS stimulation, this effect was further enhanced, whereas inflammatory factor (IL‐6 and IL‐8) release and reactive oxygen species generation were significantly decreased. Berberine effectively alleviated lung injury by reducing lung edema and neutrophil infiltration. Berberine also significantly reduced histopathological inflammatory changes via inhibition of ER stress and activation of Nrf2 signaling. Thapsigargin‐induced ER stress and small interference RNA (siRNA)‐mediated Nrf2 inhibition abrogated the protective effects of berberine in vitro, whereas siRNA‐mediated suppression of ER stress and sulforaphane‐induced Nrf2 activation further improved those effects. Importantly, ER stress induction led to Nrf2 activation, whereas PERK depletion partly reduced the level of Nrf2 phosphorylation and translocation in LPS‐induced cells. Therefore, berberine inhibits LPS‐induced ALI through the PERK‐mediated Nrf2/HO‐1 signaling axis.