Survival of activated human T lymphocytes is promoted by retinoic acid via induction of IL-2

At the end of an immune response, most activated T cells spontaneously undergo programmed cell death (apoptosis). In the present study we show that all-trans retinoic acid (atRA), a major vitamin A metabolite, can inhibit the spontaneous apoptosis of activated human T lymphocytes in vitro. Isolated peripheral blood T lymphocytes were activated by 12-O-tetradecanoyl phorbol 13-acetate and cultured for up to 11 days without any further stimuli. With time, a gradual increase in cell death was observed. This spontaneous death of activated T cells was apoptotic, as demonstrated by cell shrinkage, DNA fragmentation and depolarization of the mitochondrial membrane. In the presence of physiological concentrations of atRA, the percentage of T cells exhibiting these apoptotic features was significantly reduced. After 5 days of stimulation, the percentage of TUNEL+ T cells decreased from 28 to 12% in the presence of atRA. The anti-apoptotic effect of atRA was mimicked by the retinoic acid receptor (RAR)-selective agonists 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl]benzoic acid and AM-580, and totally abrogated by the RAR-selective antagonist Ro 41-5253. Cytokines of the IL-2 family have been shown to improve the survival of activated T cells. Strikingly, we found that the ability of atRA to inhibit apoptosis was significantly correlated with its ability to increase the production of IL-2. Furthermore, a blocking anti-IL-2 receptor antibody completely abrogated the anti-apoptotic effect of atRA. Together, these results suggest that retinoic acid inhibits spontaneous apoptosis of activated T lymphocytes through a RAR-dependent increase in IL-2 production.     

两条IL-6信号转导途径在人骨髓瘤细胞系U266中的相互拮抗作用

目的 研究人骨髓瘤细胞系U266中白细胞介素6（IL－6）信号转导途径及彼此之间的相互调控方式。方法 首先采用凝胶阻滞电泳（electrophoretic mobility shift assay,EMSA)方法观察分别参与两条IL－6信号转导途径的转录因子STAT3和NF－IL－6在U266细胞中的诱导激活状态并确定该细胞中的IL－6信号转导通路;继而采用转基因或化学试剂处理方法,特异性上调或下调其中一条IL－6信号途径的化,并同时观察另外一信号途径的激活状态。结果 1、以上两种转录因子分别参与的IL－6信号转导途径－－JAK／STAT和Ras/NF-IL-6,它们都能够在U266细胞中诱导激活;2、在高剂量IL－6（1－100ng/ml）刺激范围之内,一条IL－6信号途径活化水平的升高可同时导致另一条信号途径活化水平的下降。结论 在一定IL－6刺激剂量范围内,U266细胞中两条IL－6信号途径的诱导激活存在着相互拮抗作用。     

Anti-proliferative effect of levamisole on human myeloma cell lines in vitro

Levamisole has been employed as an immunomodulatory agent in conjunction with 5-fluorouracil in the treatment of colon cancer relapse. At high doses, levamisole has been shown to have both anti-cancer and immunosuppressive activities. In vitro, levamisole has been shown to potentiate the anti-proliferative effect of 5-fluorouracil in several types of tumor cell lines; however, its mechanism of cytotoxic action and its molecular targets in cells remains to be elucidated. Here, the effect of levamisole on the proliferative response of the human multiple myeloma cell lines RPMI 8226 and U266B1 was studied in vitro. Treatment of both lines with varying concentrations of levamisole for 48 and 72?h in culture resulted in a significant inhibition of proliferation (unstimulated) in a dose-dependent manner, as assessed by an 3-[(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide dye assay. Furthermore, measurements of cell viability (using a trypan blue dye exclusion assay) clearly showed that the levamisole was cytotoxic. The preliminary evaluation of the mechanism of this cytotoxic effect revealed that this drug induced apoptosis in the myeloma cells, as evidenced by increases in the levels of DNA fragmentation, release of cytochrome c into the cytoplasm, and the activation of caspase-3 activity in the cells. The results of these studies strongly suggest that levamisole could be a potent anti-myeloma agent and might be considered in the treatment of multiple myeloma in the future.     

Fas/Fas ligand (FasL)-deregulated apoptosis and IL-6 insensitivity in highly malignant myeloma cells

IL-6 is a growth factor which interferes in the apoptosis of malignant plasma cells. Here we explore its role in the spontaneous and Fas/FasL-regulated apoptosis of seven myeloma cell clones (MCC). MCC-2 and -7 were constitutively defective in Fas antigen in the presence of large membrane exposure of FasL, and showed a high rate of cell proliferation irrespective of the presence of IL-6. Cytofluorimetric analysis following propidium iodide (PI) staining revealed a minimal extent of spontaneous apoptosis, as in other IL-6-insensitive, though Fas-positive MCC, namely MCC-3 and -5. By contrast, a regular amplitude of apoptosis occurred in the remaining IL-6-dependent clones. Their propensity to cell death, as well as their FasL membrane expression, were promptly down-modulated by the cytokine, whereas no substantial effect was detected in IL-6-independent MCC. Furthermore, we investigated the quantitative secretion of FasL. Both [3-(4,5-dimethylthiazol-2-yl)-2,5diphenyl tetrazolium bromide] (MTT) cytotoxicity assay and PI staining of WC8 lymphoblasts from a Fas-transfected mouse lymphoma, incubated with supernatants from MCC, showed a variable cytocidal property, thus confirming the cellular release of FasL. However, a significant elevation of FasL secretion occurred in both Fas^? MCC, whereas molecular cloning and sequencing of Fas revealed the presence of a splicing variant, namely Fas Exo4,6Del, in the cDNA from both MCC-3 and -5, which were previously demonstrated to be unresponsive to Fas stimulation. Taken together, these data provide evidence that concurrence of IL-6 insensitivity and deregulation of apoptosis in myeloma cells reflects a high malignancy grade. It is suggested that the secretion of Fas splicing variants in Fas⁺ plasma cells, as well as the over-production of FasL in Fas^? myelomas, are differential mechanisms by which myeloma cells escape host immune surveillance.     

Bcl-2家族不同分子分别介导地塞米松在不同类型人骨髓瘤细胞系上的凋亡效应

目的：研究3种Bcl-2家族抗凋亡蛋白（Bcl-2,Bcl-xl,Bcl-1)在地塞米松（dexamethasone,DEX)诱导的不同类型人骨髓瘤细胞系凋亡过程中的作用。方法：采用MTT方法观察DEX对骨髓瘤细胞生长的影响。采用碘化丙胺（propidium iodide,PI)染色和流式细胞术分析骨髓瘤细胞经DEX处理后的凋亡情况，采用免疫印迹方法检测Bcl-2家族3种抗凋亡蛋白在骨髓瘤细胞凋亡过程中的表达改变情况。结果：DEX能够诱导IL－6依赖型骨髓瘤细胞系XG－7和IL－6非依赖型骨髓瘤细胞系Sko-007发生典型的细胞亡反应。同时XG－7细胞中Bcl-XL和Mcl-1的表达在DEX处理后明显下调，而同样条件下Sko-007细胞中则出现了Bcl-2的降解。结论：Bcl-2家族不同抗凋亡蛋白可分别介导DEX在不同骨髓瘤细胞系上的凋亡效应。     

IL-6、IL-1及TNF对人类骨髓瘤细胞系KM_2、KM_3增殖的影响

细胞因子的异常表达对骨髓瘤细胞的恶性增殖起重要作用。本文研究了IL-6、IL-1及TNF 对人骨髓瘤细胞系增殖的影响。KM_2、KM,均能分泌IL-6,以维持自身的增殖。培养体系中加入抗IL-6抗体可抑制瘤细胞的增殖,这种抑制作用可通过加入重组IL-6而逆转.在培养体系中加入重组IL-6和TNF 均可促进KM_2、KM_3的增殖,而IL-1无此作用。培养体系中加入TNF 培养后,上清中IL-6活性增高。我们的结果提示,人骨髓瘤细胞系KM_2、KM_3存在IL-6自分泌增殖机制,而TNF 可加强这种自分泌作用。     

IL—6在人骨髓瘤细胞U266中的信号转导途径与细胞增殖促进效应之间的关系

目的：研究人骨髓瘤细胞U266中IL－6信号转导途径激活与细胞增殖促进效应之间的关系。方法：首先分别采用MTT、凝胶阻滞电泳（electrwophoretic mobility shift assay, EMSA）和免疫沉淀（immunoprecipitation,IP）方法观察IL－6对U266细胞生长的影响及两条IL－6信号转导途径在U266细胞中的诱导激活状态;然后采用化学试剂处理或转基因方法观察信号途径活化状态变化与IL－6效应变化之间的关系。结果：IL－6可明显促进U266细胞增殖,并在不同剂量下诱导JAK／STAT和Ras/NF-IL-6途径活化;Ras途径活化被特异性上调和下调时,IL－6对U266细胞的生长促进效应分别得以增强和减弱;而JAK／STAT途径活化受抑时,IL－6的促细胞生长效应反而加强。结论：Ras途径的诱导激活介导了IL－6对U266细胞的增殖促进效应;而JAK／STAT途径活化介导了与IL－6促细胞增殖相反的生物学效应。     

IL-6相关转录因子在人骨髓瘤细胞系IL-6信号转导中的作用

为研究IL 6在人骨髓瘤细胞系的信号传递过程中IL 6相关转录因子的活化状态。本研究在IL 6刺激前后提取人骨髓瘤细胞Sko 0 0 7的细胞核蛋白 ,分别以APRE、NF IL 6/ATF、NF κB、CRE、AP 1作为探针 ,采用凝胶阻滞电泳 (electro phoret icmobilityshiftassay ,EMSA )方法检测IL 6刺激前后Sko 0 0 7细胞中与以上DNA反应成分对应的转录因子的活化情况。结果显示 ,NF IL 6和NF κB在正常培养的Sko 0 0 7细胞中组成性激活 ;IL 6刺激前后STAT3和NF IL 6的活化状态有明显改变 ;CREB和NF κB的活化状态无明显变化 ;AP 1的激活情况与细胞的生存状态有关。表明在Sko 0 0 7细胞中与IL 6信号传递密切相关的转录因子是STAT3和NF IL 6;对细胞本身生存至关重要的转录因子是NF IL 6和NF κB。     

卵巢癌细胞IL-6、IL-8及其受体表达的研究

目的分析比较五种常见的上皮性卵巢癌细胞系IL-6、IL-8及其受体表达的差异。方法IL-6、IL-8的表达分别采用RT-PCR和ELISA法进行检测,IL-6受体（IL-6Rα和gp130）及IL-8受体（IL-8RA和IL-8RB）的表达采用免疫印迹技术进行测定。结果①五种上皮性卵巢癌细胞均组成性表达IL-6和IL-8。IL-6和IL-8在CAOV-3细胞中的表达水平均最高,而在HO-8910PM细胞中的表达水平均最低,IL-6在SKOV-3、HO-8910、OVCAR-3细胞中的表达水平依次降低,IL-8在OVCAR-3、SKOV-3、HO-8910细胞中的表达水平依次降低。②五种上皮性卵巢癌细胞均表达IL-6Rα、gp130及IL-8RA;除CAOV-3细胞外,其它细胞均表达IL-8RB。结论本研究旨在筛选表达IL-6和IL-8及其相应受体的细胞株,为研究IL-6、IL-8与卵巢癌发生、发展关系奠定基础,同时也为今后卵巢癌的免疫治疗提供一个新的思路。     

Ex vivo all-trans retinoic acid modulates NO production and regulates IL-6 effect during rheumatoid arthritis: a study in Algerian patients

Rheumatoid arthritis (RA) is a chronic autoimmune disease. The pathophysiology of RA implicates several mediators such as nitric oxide (NO) and cytokines such as interleukin-6 (IL-6), which is deeply involved in the main characteristics of RA. Furthermore, all-trans retinoic acid (ATRA) is an active vitamin A derivative well-known to have diverse immunomodulatory actions. In our study, we investigated first, the ex vivo immunomodulatory potential of ATRA on NO pathway by peripheral blood mononuclear cells (PBMCs) from Algerian RA patients. Then, we assessed the possible regulatory effect of ATRA on NO production induced by IL-6. PBMCs isolated from active and inactive RA patients and healthy controls were cultured with different concentrations of IL-6 or/with ATRA. NO production was assessed using the Griess method. Inducible nitric oxide synthase expression and NF-κB activity were analyzed by immunofluorescence test. Our results revealed a high NO production during active RA. We noticed that while IL-6 induced a high NO production and iNOS expression, ATRA downregulated both. ATRA also inhibited nuclear NF-κB translocation. Interestingly, it seems that NO production mediated by IL-6 on PBMCs of RA patients is downregulated by ATRA. Taken together, our results highlight the immunomodulatory effect of ATRA on NO pathway in RA patients and its possible role in regulating IL-6-mediated NO production. All these findings suggest its potential therapeutic role during RA.     

cAMP对人骨髓瘤细胞的IL-6信号转导功能及细胞增殖的抑制作用

目的 研究ＰＫＡ途径激活（或胞内ｃＡＭＰ水平升高）后对人骨髓瘤细胞的ＩＬ－６信号转导功能及细胞生长的影响。方法 采用ＰＫＡ途径激动剂Ｆｏｓｋｏｌｉｎ（ＦＫ）和ｃＡＭＰ类似物８－Ｂｒ－ｃＡＭＰ刺激人骨髓瘤细胞骨－Ｓｋｏ－００７,分别通过ＭＴＴ方法和凝胶阻滞电泳（ｅｌｅｃｔｒｏｐｈｏｒｅｔｉｃ ｍｏｂｉｌｉｔｙ ｓｈｉｆｔ ａｓｓａｙ,ＥＭＳＡ）方法检测ＦＫ和８－Ｂｒ－ｃＡＭＰ对Ｓｋｏ细胞的生长及其Ｉ     

IL-6 and soluble IL-6 receptors (sIL-6R and sgp130) in human pleural effusions: massive IL-6 production independently of underlying diseases

IL-6, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130) levels were measured in sera and pleural effusions from 42 patients with metastatic carcinoma, non-Hodgkin's lymphoma, tuberculosis, cardiac failure and miscellaneous diseases. Pleural IL-6 levels measured by ELISA were very high in all patient groups (mean 34.8 ± 15.3 ng/ml) without significant difference according to diseases. IL-6 was shown to be biologically active in a proliferative assay. Serum IL-6 levels were low (0.049 ± 0.014 ng/ml) and did not correlate with pleural fluid levels. Pleural IL-6 levels correlated with the number of polymorphonuclear cells in pleural fluid (P< 0.03). Pleural sIL-6R levels (76 ± 8 ng/ml) were always lower than serum levels (196 ± 12 ng/ml; P< 0.0001) but correlated with them (P< 0.01). Pleural sIL-6R and albumin levels correlated (P< 0.01), suggesting a transudation of sIL-6R from the serum. Pleural sgp130 levels (10.9 ± 1.0 ng/ml) were lower than serum levels (24.6 ± 2.8 ng/ml; P< 0.002). After gel filtration of pleural fluid, the bulk of IL-6 (>90%) was recovered in a 15 000–30 000 fraction, corresponding to the expected mol. wt of free IL-6. These results suggest a production and a sequestration of IL-6 in the pleural cavity in all studied conditions.     

Differential regulation of interleukin-6 receptors by interleukin-6 and interferons in multiple myeloma cell lines

Interleukin-6 (IL-6) mediates pleiotropic functions through specific receptors (IL-6R) composed of an 80-kDa binding protein, associated with a non-ligand binding protein (gp130) which transduces the signal. Because IL-6 is the major tumor growth factor in multiple myeloma, we investigated the regulation of IL-6R in two human multiple myeloma cell lines. Binding experiments with ¹²⁵I-labeled IL-6 showed that IL-6R were expressed at a high density on RPMI-8226 cells (15 000 receptors/cell), but no specific binding was detected on XG-1 cells, whose growth depends on the presence of exogenous IL-6. However, when IL-6 was removed from the culture medium, high-affinity IL-6R appeared on the surface of XG-1 cells (5300 sites/cell). Treatment of RPMI-8226 cells with IL-6 reduced the number of IL-6R without changing their affinity. This reduction was dose dependent and was not affected by acid treatment which dissociates ligand-receptor complexes. Cross-linking experiments showed that the formation of one IL-6/receptor complex of 160 kDa markedly decreased upon IL-6 treatment, while the other complex of 190 kDa became undetectable. These data provide evidence for ligand-induced down-regulation of membrane IL-6R expression in myeloma cells. Treatment of RPMI-8226 cells with interferon-α (IFN-α), which inhibits the growth of these cells, stimulated IL-6R expression and increased the formation of the 160-kDa IL-6/receptor complex. This stimulation was specific for IFN-α, since IFN-γ reduced the number of IL-6R. These data indicate that, in myeloma cells, IL-6R are differentially regulated by IL-6 and IFN-α.     

IL-6抑制地塞米松诱导的人骨髓瘤细胞凋亡

目的 :研究地塞米松 (Dexamethasone ,DEX)诱导人骨髓瘤细胞系Sko 0 0 7凋亡的分子机制及IL 6对此凋亡作用的抑制效应。方法 :MTT法观察DEX对Sko 0 0 7细胞生长的影响 ;碘化丙腚 (propidiumiodide ,PI)染色和流式细胞术分析Sko 0 0 7细胞经DEX处理后的凋亡情况 ;免疫印迹法检测Bcl 2家族抗凋亡蛋白———Bcl 2、Bcl XL 和Mcl 1在Sko 0 0 7细胞凋亡过程中的表达情况。结果 :DEX能够抑制Sko 0 0 7细胞增殖并诱导其发生凋亡 ;同时促进胞内Bcl 2降解。IL 6抑制DEX诱导的Sko 0 0 7细胞凋亡 ,并使Bcl 2表达水平恢复。结论 :IL 6可通过调节Bcl 2表达而实现其对DEX诱导的骨髓瘤细胞凋亡的抑制作用。     

Inverse regulation of interleukin-6 (IL-6) and IL-6 receptor in histamine deficient histidine decarboxylase-knock-out mice

Interleukin-6, a multifunctional cytokine upon binding to its receptor on hepatocytes regulates production of acute phase proteins involved in local and systemic inflammation. Gene expression and biosynthesis of IL-6 and its receptor (IL-6 R/gp130) is under complex regulation. Histamine, in addition to its principal role in immediate type hypersensitivity has been described to modulate IL-6 production and expression of IL-6 receptor. In this study, the IL-6 and IL-6 receptor expression was examined in histamine deficient histidine decarboxylase (HDC) knock-out mouse model. Our data suggest that in histamine deficient mice the inducibility of IL-6 is significantly reduced, whilst more IL-6 receptor/gp130 mRNA expresses in the liver than in wild type (HDC^+/+) mice. These in vivo findings confirm earlier in vitro results and emphasize the efficacy of antihistamines in local IL-6 related processes.     

Retinoic acid inhibits CD40 plus IL-4 mediated IgE production through alterations of sCD23, sCD54 and IL-6 production

Background: All-trans retinoic acid (ATRA) inhibits IgE synthesis from anti-CD40 plus IL-4 stimulated human B lymphocytes.Objective: To study the underlying mechanisms, we examined here molecules which are known to have an impact on IgE production, namely CD23, CD54 and IL-6.Methods: Human anti-CD40 plus IL-4 stimulated B cells were cultured in the absence and presence of ATRA (10^–6–10^–10 M). ELISAs were performed to determine soluble (s) CD23 and sCD54, IL-6 and IgE-levels. CD23 and CD54 surface expression were determined by flow cytometric analysis. Semiquantitative-RT-PCR was employed to analyse IL-6, CD23 and CD54 mRNA expression.Results: ATRA induced a dose-dependent increase of percent CD23 (3.4 fold) or CD54 (1.6 fold) positive B cells. At the mRNA level, this was reflected by a modest increase of CD54 mRNA (46.5 ± 15.8%) only. By contrast, levels of sCD54 were decreased dose-dependently in the presence of ATRA (56.6 ± 7.6%). Cytokine analysis showed that IL-6 secretion was significantly inhibited by ATRA (53.6 ± 0.6%) and also IL-6 mRNA synthesis was reduced (66.3 ± 11.6%). The observed inhibition of IgE production mediated by ATRA was significantly reversed to 90.5 ± 12% by the addition of 100 pg/mL recombinant IL-6.Conclusions: ATRA interferes through several pathways with the anti-CD40 plus IL-4 mediated B cell activation, namely IL-6, CD23 and CD54.Received 8 June 2004; returned for revision 19 July 2004; accepted by M. J. Parnham 5 November 2004     

IL-1对维甲酸诱致高白细胞症的影响

使用生物活性检测法检测ATRA治疗前后APL患者血清中IL-1活性的动态变化,并分析IL-1活性与外周血白细胞数变化的相关性。观察经ATRA作用后不同时相NB4细胞、巨噬细胞和血管内皮细胞上清液中IL-1活性的动态变化,并以RT-PCR法检测NB4细胞中IL-1 mRNA表达的变化。结果表明,患者外周血白细胞数及粒细胞数与血清中IL-1活性的变化相关;ATRA作用后,NB4细胞、巨噬细胞和血管内皮细胞上清液中IL-1活性均呈时间依赖性增高;ATRA可上调NB4细胞中IL-1的表达。结论:ATRA治疗APL过程中,多种细胞来源的IL-1可能参与了高白细胞症的发生。     

NF-κB哑铃形诱骗剂ODN对骨髓瘤细胞生长及IL-6表达的抑制作用

目的设计合成靶向NF-κB的哑铃形诱骗剂ODN,分析靶向NF-κB的哑铃形诱骗剂对NF-κB转录活性、多发性骨髓瘤细胞8266的生长及其分泌的IL-6的抑制效应。方法采用电泳迁移率变动分析(EMSA)体外检测诱骗剂ODN对NF-κB转录活性的抑制效应。将8266细胞随机分为传代培养的8266细胞组;诱骗剂ODN处理组及脂质体处理组。通过阳离子脂质体以2mg/L、4mg/L、8mg/L不同剂量诱骗剂ODN转染8266细胞。转染后8、12、18h,ELISA法检测8266细胞培养上清中IL-6的表达。用MTT比色检查诱骗剂ODN对IL-6刺激的8266细胞生长的影响。结果硫代磷酸的诱骗剂ODN在体外能有效地抑制NF-κB与其顺式元件的结合;2mg/L、4mg/L、8mg/L等不同浓度的脂质体-ODN复合物对8266细胞表达IL-6的抑制程度不同。脂质体-ODN复合物对8266细胞的生长及IL-6的活性均有抑制作用。结论靶向NF-κB的诱骗剂ODN在体外可抑制NF-κB的转录活性,从而抑制8266细胞的生长,降低瘤细胞中IL-6的表达。     

Major role of the soluble interleukin-6/interleukin-6 receptor complex for the proliferation of interleukin-6-dependent human myeloma cell lines

Interleukin-6 (IL-6) is a proinflammatory cytokine which possesses a central growth factor activity for certain tumor cells such as plasma cells in multiple myeloma (MM). Upon binding of IL-6, soluble IL-6 receptor (sIL-6R) has been shown to retain its affinity for IL-6 and to associate with the signal-transducing gp130 chain. Therefore, contrary to the majority of soluble cytokine receptors, it plays an agonist role in IL-6 signaling. In order to test its physiological importance as compared to that of its membrane counterpart, we studied cells from two myeloma cell lines which need exogenous IL-6 to proliferate and release sIL-6R into their culture supernatant. Using a new culture system where the supernatant recirculated permanently through an anti-IL-6R affinity column, all sIL-6R was removed from the culture medium throughout the culture period. Under these conditions IL-6-dependent cells were unable to grow in the presence of physiological concentrations of IL-6, showing the major role of the sIL-6R for sustaining the proliferation of these cell lines. Increasing IL-6 concentrations well over the physiological values allowed the cells to proliferate again. No effect was seen when sIL-6R was removed from the supernatant of an IL-6-independent myeloma cell line. These results show that the levels of circulating sIL-6R (and thus those of IL-6/sIL-6R complex) are worth looking at in pathologies involving IL-6 hyperactivity.     

马钱子碱通过抑制IL-6/STAT3信号通路诱导结肠癌SW480细胞凋亡

目的:探讨马钱子碱(brucine)在体外对人结肠癌SW480细胞生长和凋亡的影响及可能的分子机制。方法:实验以人结肠癌细胞系SW480细胞为研究对象,分为空白对照组、brucine(1μmol/L)处理组、IL-6(100μg/L)处理组和brucine(1μmol/L)与IL-6(100μg/L)联用组,用CCK-8法检测细胞活力抑制率;流式细胞术Annexin V/PI双染法检测细胞凋亡;Western blot法检测凋亡相关蛋白表达。细胞免疫荧光检测相关蛋白表达定位和强度。结果:Brucine处理组和brucine与IL-6联用组都能抑制结肠癌细胞的活力,brucine浓度相同时,联用组抑制率小于brucine处理组(P0.05)。与空白对照组相比,单用brucine处理组凋亡细胞明显增多(P0.05)。与单用brucine相比,brucine与IL-6联用组凋亡细胞明显减少(P0.05)。与对照组相比,brucine能降低p-STAT3蛋白水平。与空白对照组相比,单用brucine组p-STAT3的蛋白减少,抗凋亡蛋白Bcl-2表达减少,促凋亡蛋白Bax和执行凋亡的cleaved PARP明显增多;与空白对照组相比,单用IL-6处理组的p-STAT3明显增多(P0.05);而与单用brucine相比,brucine与IL-6联合应用组的p-STAT3蛋白增多,抗凋亡蛋白Bcl-2表达增多,促凋亡蛋白Bax和执行凋亡的cleaved PARP均相对减少(P0.05)。结论:体外细胞实验中brucine可能通过调节IL-6/STAT3通路,抑制结肠癌SW480细胞中STAT3的磷酸化激活,从而发挥抗肿瘤作用。