川芎嗪注射液对高眼压大鼠视网膜神经节细胞凋亡的作用机制研究

目的 观察川芎嗪注射液通过磷脂酰肌醇-3激酶/丝氨酸-苏氨酸蛋白激酶/哺乳动物雷帕霉素靶蛋白(PI3K/Akt/mTOR)通路对高眼压大鼠模型视网膜神经节细胞凋亡的影响.方法 用前房注射羟丙基甲基纤维素的方法建立高眼压大鼠模型.按照体重将造模成功大鼠随机分为4组:模型组、川芎嗪组、激动剂组和抑制剂组;另取10只正常大鼠...     

川芎嗪对顺铂肾损伤大鼠肾细胞凋亡及凋亡相关蛋白表达的影响

目的探讨川芎嗪(TMP)对顺铂(DDP)大鼠肾毒性有无保护作用。方法DDP8mg·kg-1ip诱导大鼠肾损伤,于给予DDP2d前大鼠分别ip50,100mg·kg-1·d-1TMP,连续5d,于给药d5收集各组大鼠尿液,测24h尿蛋白含量,并于末次给药后4h处死大鼠,测血清尿素氮(BUN)和肌酐(Cr)含量,采用原位缺口末端标记法检测肾脏细胞凋亡,免疫组化SP法检测肾脏Bax和Bcl2蛋白表达水平。结果50,100mg·kg-1TMP组可降低DDP所致大鼠24h尿蛋白及血清BUN和Cr含量的升高(P<0.01);TMP两剂量组也可明显减少肾脏细胞凋亡率(P<0.01),显著增强肾脏凋亡相关蛋白Bcl2的表达,减少Bax表达,并明显降低Bax/Bcl2比值(P<0.01)。结论TMP可能通过降低凋亡相关蛋白Bax和增强Bcl2的表达,并降低Bax/Bcl2比值而抑制DDP引起的肾细胞凋亡,使肾脏免受损伤的作用。     

Dipyridamole inhibits lipopolysaccharide-induced cyclooxygenase-2 and monocyte chemoattractant protein-1 via heme oxygenase-1-mediated reactive oxygen species reduction in rat mesangial cells

Dipyridamole contributes to its beneficial effects on inflammatory responses in many cell types. The anti-inflammatory mechanisms of dipyridamole on glomerular mesangial cells are mostly uncharacterized. In this study, we monitored the influence of dipyridamole on the expression levels of cyclooxygenase-2 (COX-2) and monocyte chemoattractant protein-1 (MCP-1) in rat mesangial cells stimulated with lipopolysaccharide. Dipyridamole was found to inhibit lipopolysaccharide-induced COX-2 and MCP-1 expression, and reduced lipopolysaccharide-induced reactive oxygen species generation in rat mesangial cells. This inhibitory effect of dipyridamole is independent on cyclic AMP and cyclic GMP increase. Tin protoporphyrin IX (SnPP), a heme oxygenase-1(HO-1) inhibitor, blocked the inhibitory effect of dipyridamole on lipopolysaccharide-induced COX-2 and MCP-1 expression. By applying specific inhibitors in rat mesangial cells, ERK1/2 and p38 MAPK signaling pathways were demonstrated to be involved in the lipopolysaccharide-induced inflammatory responses, and were inhibited by SnPP and N-acetylcysteine treatment. Additionally, dipyridamole was also found to upregulate HO-1 in rat mesangial cells. Therefore, our data suggest that dipyridamole inhibits the expression of COX-2 and MCP-1 in lipopolysaccharide-treated rat mesangial cells via HO-1-mediated reactive oxygen species reduction.     

川芎嗪联合mTOR抑制剂调控卵巢癌SKOV-3细胞增殖、侵袭迁移的实验研究

目的 研究川芎嗪联合mTOR抑制剂对卵巢癌SKOV-3细胞增殖、侵袭迁移的作用.方法 分别设置对照组、40μmol/L川芎嗪组、5μmol/L雷帕霉素组、40μmol/L川芎嗪联合5μmol/L雷帕霉素组,各组SKOV-3细胞给药后继续培养48 h后,MTT法考察各组SKOV-3细胞的增殖抑制率,Transwell实验...     

丹酚酸 A对脂多糖诱导人肾小球系膜细胞凋亡的作用机制研究

目的探究丹酚酸 A对脂多糖(lipopolysaccharide,LPS)诱导人肾小球系膜细胞凋亡的作用机制。方法该研究起止时间为 2018年 5月至 2019年 5月。购买华拓生物生产的 HGMC人肾小球系膜细胞,分为 A组、 B组、 C组、 D组、 E组五组, A组细胞不添加任何药物, B组、 C组、 D组、 E组细胞均加入 10 mg/L LPS培养, 1h后 C组、 D组、 E组分别加入低剂量丹酚酸 A(10 mg/L)、中剂量丹酚酸 A(20 mg/L)、高剂量丹酚酸 A(40 mg/L)处理 24 h后做后续试验。检测细胞增殖、凋亡、细胞周期分布以及磷脂酰肌醇 3激酶(PI3K)/蛋白激酶 B(protein kinase,AKT)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路指标表达量。结果与 A组相比, B组细胞凋亡率、 G0/G1期细胞分布率降低, S期、 G2/M期细胞分布率升高;与 B组相比, C组、 D组、 E组 G0/G1期细胞分布率、细胞凋亡率升高, S期、 G2/M期细胞分布率降低;与 C组相比, D组、 E组细胞凋亡率、 G0/G1期细胞分布率升高, S期、 G2/M期细胞分布率降低(均 P<0.05);与 D组相比, E组细胞凋亡率(37.59±4.62)%、G0/G1期细胞分布率(86.95±11.62)%升高, S期、 G2/M期细胞分布率分别为     

新型金属铜络合物对SMMC-7721细胞增殖与凋亡的影响

目的研究新型金属铜络合物(N-Cu)在体外对人肝癌SMMC-7721细胞增殖与凋亡的影响及其作用机制。方法将不同浓度的N-Cu(0.3～24μmol.L-1)作用于体外培养的SMMC-7721细胞,应用MTT法检测细胞生长抑制率,FCM法检测细胞周期及凋亡率,RT-PCR和Western blot法检测细胞中Bcl-2、Bax、Caspase-3 mRNA和蛋白表达的变化。结果 N-Cu可明显抑制SMMC-7721细胞的增殖,呈明显的量效与时效关系。随着药物浓度的增加,G0/G1期的细胞比率上升,G2/M和S期细胞比率下降,并促进凋亡率增加。N-Cu可上调细胞中Bax、Caspase-3基因及蛋白的表达,抑制Bcl-2基因及蛋白的表达,且均呈剂量依赖性。结论一定浓度的N-Cu可抑制SMMC-7721细胞的增殖并诱导其凋亡,阻滞细胞周期于G0/G1期。上调Bax、Caspase-3基因及蛋白的表达,降低Bcl-2/Bax比值,可能是其诱导细胞凋亡的重要机制。     

Protective effects of ligustrazine on TNF-α-induced endothelial dysfunction

To investigate the effects of Ligustrazine, a compound derived from chuanxiong, on tumor necrosis factor-α (TNF-α) stimulated endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with TNF-α in vitro. Nitric oxide (NO) was measured as a standard of endothelial dysfunction. Two important indicators of autoimmunity, intracellular adhesion molecular-1 (ICAM-1) and heat shock protein 60 (HSP60), were selected to evaluate the influence of Ligustrazine on HUVECs. Ligustrazine (40 μg/ml) significantly reversed the decrease in NO production induced by TNF-α (5 ng/ml) in HUVECs. The expressions of ICAM-1 and HSP60 were increased by TNF-α treatment, but dramatically inhibited by treatment with ligustrazine in TNF-α-stimulated cells. Ligustrazine increased the production of NO in HUVECs and had an immunomodulatory effect on HUVECs stimulated with TNF-α by down-regulating the expression of ICAM-1 and HSP60. These results suggest that ligustrazine protects the endothelium via inhibition of immunological reactions, preventing atherosclerosis.     

Bcl-2 siRNA induced apoptosis and increased sensitivity to 5-fluorouracil and HCPT in HepG2 cells

To investigate the changes in drug sensitivity of Bcl-2 siRNA transfected HepG2 cells. Bcl-2 siRNA and negative siRNA expression vector were constructed and stably transfected into HepG2 cells. RT-PCR and Immunofluorescence were used to detect the target gene expression. Western Blotting was used to detect Bcl-2, Bax and caspase-3 protein expressiom. Drug sensitivity of the cells to 5-fluorouracil (5-FU) and 10-hydroxycamptothecin (HCPT) were analyzed with MTT and flow cytometry. Results were following: (1) the mRNA and protein expression level of Bcl-2 in Bcl-2 siRNA stable transfectants were reduced compared with negative siRNA transfected or untreated cells. Accordingly, Bax protein expression had no change and caspase-3 protein expression showed significantly be up regulated; (2) MTT results showed that Bcl-2 siRNA transfectants had higher cell inhibitory rates after treated with 5-FU or HCPT; (3) flow cytometry results demonstrated that sub G1 population increased in Bcl-2 siRNA transfected cells compared with negative siRNA or untreated cells. After addition 5-FU (1300 mg/l) and HCPT (0.72 mg/l), Bcl-2 siRNA cells showed higher sub G1 population than negative siRNA or untreated cells. siRNA targeting Bcl-2 gene can specifically down-regulate Bcl-2 expression, increased Bax/Bcl-2 ratio expression and caspase-3 activity in HepG2 cells, which lead to increase cells spontaneous apoptosis and sensitize cells to 5-FU or HCPT. Bcl-2 siRNA may be a potential therapy agent against human hepatoblastoma.     

Bcl-2 siRNA induced apoptosis and increased sensitivity to 5-fluorouracil and HCPT in HepG2 cells

To investigate the changes in drug sensitivity of Bcl-2 siRNA transfected HepG2 cells. Bcl-2 siRNA and negative siRNA expression vector were constructed and stably transfected into HepG2 cells. RT-PCR and Immunofluorescence were used to detect the target gene expression. Western Blotting was used to detect Bcl-2, Bax and caspase-3 protein expressiom. Drug sensitivity of the cells to 5-fluorouracil (5-FU) and 10-hydroxycamptothecin (HCPT) were analyzed with MTT and flow cytometry. Results were following: (1) the mRNA and protein expression level of Bcl-2 in Bcl-2 siRNA stable transfectants were reduced compared with negative siRNA transfected or untreated cells. Accordingly, Bax protein expression had no change and caspase-3 protein expression showed significantly be up regulated; (2) MTT results showed that Bcl-2 siRNA transfectants had higher cell inhibitory rates after treated with 5-FU or HCPT; (3) flow cytometry results demonstrated that sub G1 population increased in Bcl-2 siRNA transfected cells compared with negative siRNA or untreated cells. After addition 5-FU (1300 mg/l) and HCPT (0.72 mg/l), Bcl-2 siRNA cells showed higher sub G1 population than negative siRNA or untreated cells. siRNA targeting Bcl-2 gene can specifically down-regulate Bcl-2 expression, increased Bax/Bcl-2 ratio expression and caspase-3 activity in HepG2 cells, which lead to increase cells spontaneous apoptosis and sensitize cells to 5-FU or HCPT. Bcl-2 siRNA may be a potential therapy agent against human hepatoblastoma.     

没食子乙醇提取物对结肠癌细胞JAK2/STAT3信号通路的调控作用研究

目的 基于蛋白酪氨酸激酶2(JAK2)/信号传导及转录活化因子3(STAT3)信号通路研究没食子乙醇提取物对结肠癌细胞HCT-116、Caco-2增殖、迁移的调控机制.方法 采用CCK-8法检测0.05、0.1、0.2、0.3、0.4、0.5 mg/mL没食子乙醇提取物作用12、24、48、72 h后对HCT-116、...     

川芎嗪对缺氧时视网膜血管内皮细胞HIF-1α、VEGF表达及细胞增殖的影响

目的研究川芎嗪对缺氧时体外培养的牛眼视网膜血管内皮细胞（BREC）VEGF表达及细胞增殖活性的影响,探讨川芎嗪治疗视网膜新生血管性疾病的药理机制及可行性。方法 CoCl2模拟缺氧处理培养的BREC细胞,用浓度分别为20、40、120μg/mL的川芎嗪分别加入细胞培养液中24h,采用ELISA法检测细胞培养上清液VEGF含量,免疫组织化学法和生物荧光法分别检测细胞PCNA的表达、细胞内ATP含量以分析细胞增殖能力,采用免疫组织化学法检测HIF-1α的表达。结果川芎嗪可减少缺氧引起的视网膜血管内皮细胞中PCNA的表达,降低细胞内ATP含量,降低培养上清液中的VEGF浓度,且呈剂量依赖性。结论川芎嗪可抑制缺氧引起的视网膜血管内皮细胞的增殖。其机制可能是通过抑制HIF-1α途径来实现的。     

Molecular effects of chemotherapeutic drugs and their modulation by antioxidants in the testis

Cisplatin-based chemotherapy regimens are preferred in the treatment of a variety of cancers. The present study investigated early cumulative molecular effects of therapeutic dose-levels of bleomycin, etoposide and cisplatin (BEP) in the testis and their modulation by an antioxidant cocktail (AO). Adult male Sprague-Dawley rats (N=7/group [G]) were treated with BEP as follows: G1 - control; G2 - AO (α-tocopherol [100 mg/kg], l-ascorbic acid [50 mg/kg], Zn [40 mg/l] and Se [100 μg/l]); G3 - B, 1.5 mg/kg on day 2; E, 15 mg/kg and P, 3 mg/kg for 4 days, and G4 - similar to G3 but also treated with AO for 4 days. In G3, the testis weight, sperm count and motility, and activities of enzymatic antioxidants decreased and lipid peroxidation increased compared to that in G1 (P<0.05). Seminiferous epithelial sloughing and degeneration were observed. In G3, mRNA levels of p53, Bcl-2 and Bax were unaltered but protein expression of p53 and Bax was up-regulated and that of Bcl-2 was down-regulated (P<0.05). These changes led to an increase in terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) positive germ cells indicating cell death (P<0.05). The AO recovered the BEP-induced molecular alterations to control levels. The mechanism of BEP-induced early testicular damage involves the initiation of oxidative stress, up-regulation of pro-apoptotic proteins and induction of cell death. Further, the induced testicular structural changes are negligible and less than those observed in single drug exposure studies reported in literature. The AO significantly ameliorates the BEP-induced pathogenesis of testicular damage suggesting its potential therapeutic uses.     

莪术油对直肠癌SW1463细胞株增殖、凋亡及Caspase-3、Bax、Bcl-2蛋白表达的影响

目的 探讨莪术油对直肠癌SW1463细胞株增殖、凋亡及相关蛋白Caspase-3、Bax、Bcl-2表达的影响。方法 水蒸气蒸馏法提取黔产莪术挥发油,配制成40、80、120、160、200、240、280 mg/L浓度梯度,干预SW1463细胞24、48、72 h,MTT法检测莪术油对SW1463细胞的增殖抑制率;Giemsa染色法观察莪术油对SW1463细胞凋亡形态的影响;蛋白免疫印迹法（Western blotting）检测Capase-3、Bax与Bcl-2蛋白表达。结果 莪术油对SW1463细胞的增殖有明显抑制作用,并呈现时间-剂量相关性,24、48、72 h的半数抑制浓度（IC₅₀）分别为144.33、134.11、120.04 mg/L;Giemsa染色可见细胞明显的凋亡形态学特征;莪术油干预SW1463细胞24 h后,与对照组比较,Caspase-3、Bax蛋白表达显著上调、Bcl-2蛋白表达显著下调（P<0.05）。结论 莪术油能明显抑制SW1463细胞增殖,诱导细胞凋亡,其机制可能与上调Caspase-3和Bax蛋白表达、下调Bcl-2蛋白表达相关。     

YC-1-inhibited proliferation of rat mesangial cells through suppression of cyclin D1-independent of cGMP pathway and partially reversed by p38 MAPK inhibitor

This study was designed to investigate the effect of 1-benzyl-3-(5'-hydroxymethyl-2'-furyl) indazole (YC-1), a guanylate cyclase activator, upon the proliferation of rat mesangial cells and its underlying mechanism. YC-1 inhibited cell proliferation and DNA synthesis in a dose- and time-dependent manner. Flow cytometry cell-cycle studies revealed that YC-1 prevented the entry of cells from G1 into S phase. The expression of cyclin D1 and the kinase activity of cyclin D1/cyclin-dependent kinase (CDK)4 were lower within YC-1-treated cells, revealed by Western blotting, Northern blotting and kinase assays. YC-1 did not increase the intracellular cGMP concentration in mesangial cells. Inhibitors of soluble guanylate cyclase, protein kinase G, or protein kinase A also did not reverse the inhibitory effect elicited by YC-1, while co-treatment with p38 mitogen-activated protein kinase (MAPK) inhibitor could partially reverse the suppressive effect. YC-1 inhibited proliferation of mesangial cells and induced cell-cycle arrest by the reduction of cyclin D1 synthesis and cyclin D1/CDK4 kinase activity. This effect acts partially through p38 MAPK signal transduction activation and is independent of cGMP-signaling pathways.     

川芎嗪逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的作用及机制研究

目的： 研究川芎嗪（Ligustrazine）逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的作用,以及对肿瘤细胞中耐药相关蛋白ABCB1、ABCC1和ABCG2表达的影响。方法： MTS法研究川芎嗪逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的IC₅₀值和逆转耐药系数;流式细胞实验研究川芎嗪对脂肪细胞介导的耐药卵巢癌细胞的凋亡水平的影响;划痕实验研究川芎嗪对脂肪细胞介导的耐药卵巢癌细胞的迁移能力的影响;Western Blot研究川芎嗪对肿瘤细胞中耐药相关蛋白ABCG1、ABCC1和ABCG2表达水平。结果： 川芎嗪能够逆转脂肪细胞介导的卵巢癌奥沙利铂耐药,其逆转耐药系数为2.8;川芎嗪能够增加脂肪细胞和肿瘤细胞共培养体系下肿瘤细胞的凋亡;川芎嗪能够抑制脂肪细胞和肿瘤细胞共培养体系下肿瘤细胞的迁移;川芎嗪能够减少肿瘤细胞中耐药相关蛋白ABCB1、ABCC1和ABCG2的表达。结论： 川芎嗪能够逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的作用且其机制与减少耐药相关蛋白ABCB1、ABCC1和ABCG2的表达有关。     

Ski在全反式维甲酸抑制TGF-β1诱导的系膜细胞增殖中的作用

【摘要】目的 探讨全反式维甲酸（ATRA）对转化生长因子(TGF)-β1诱导的大鼠系膜细胞增殖及Ski表达的影响。方法 不同浓度ATRA预处理大鼠HBZY-1系膜细胞（为各剂量ATRA组）24 h后再加TGF-β1 (10 μg/L)培养24 h。 CCK-8法检测细胞增殖情况;Real-time PCR法检测Ski mRNA的表达;Western blot检测Ski蛋白的表达;激光共聚焦荧光显微镜检测Ski蛋白的亚细胞定位。并与正常对照组及TGF-β1组比较。结果 与正常对照组相比,TGF-β1组系膜细胞增殖明显,且Ski mRNA及蛋白表达升高(P < 0.05);与TGF-β1 组相比,ATRA能够呈剂量依赖性地抑制 TGF-β1的促增殖作用,ATRA 10 μmol/L组Ski mRNA及蛋白表达量明显增高。ATRA组Ski蛋白主要定位于大鼠系膜细胞核,其细胞核荧光信号强度较TGF-β1组明显增强,细胞浆中荧光信号强度较TGF-β1组减弱。结论 ATRA可通过上调大鼠系膜细胞Ski表达,抑制其向核外转位,从而抑制TGF-β1诱导的系膜细胞增殖。     

薏苡仁脂调控凋亡相关蛋白Bax、Bcl-2及Survivin增强胰腺癌细胞对吉西他滨敏感性的研究

目的研究薏苡仁脂增强胰腺癌细胞系BXPC3对吉西他滨化疗敏感性的分子作用机制。方法 MTT法检测不同浓度薏苡仁脂与吉西他滨对BXPC3细胞系增殖活性的影响;Annexin V-FITC/PI双染料标记-流式细胞技术检测不同药物对BXPC3细胞系凋亡率;Western bolt技术检测不同药物处理对BXPC3细胞系Caspase-3、Bax、Bcl-2及Survivin蛋白表达影响。结果薏苡仁脂可明显降低吉西他滨杀伤BXPC3细胞的IC50,增强吉西他滨诱导细胞凋亡作用,逆转吉西他滨诱导的Bcl-2、Survivin蛋白表达上调,提高Bax/Bcl-2比值。结论薏苡仁脂可通过抑制抗凋亡蛋白Bcl-2、Survivin表达,增强促凋亡蛋白Bax表达,增强胰腺癌细胞BXPC3对吉西他滨的化疗敏感性。     

Modulation of human monocyte-derived dendritic cells maturation by a soluble guanylate cyclase activator, YC-1, in a cyclic nucleotide independent manner

This study evaluated how YC-1, a guanylate cyclase activator, affects the maturation of human monocyte-derived dendritic cells. Maturation markers and intracellular signaling pathways were evaluated. YC-1 inhibited the lipopolysaccharide up-regulation of mature markers, including CD40, CD80 or CD86 in a concentration-dependent manner with IC(50) values of 4.6+/-0.4, 4.9+/-0.6 or 4.5+/-0.5 microM, respectively. YC-1, at a higher concentration, inhibited lipopolysaccharide-induced HLADR expression. These effects of YC-1 were not reversed by ODQ (10 microM), which is a soluble guanylate cyclase inhibitor, nor by KT5823 (1 microM), which is a PKG inhibitor. Additionally, YC-1 did not increase levels of cyclic nucleotides in dendritic cells, supporting the claim that YC-1 affects dendritic cells maturation in a cGMP-independent manner. YC-1, in a cGMP-independent manner, inhibited lipopolysaccharide-induced Akt activation, IkappaBalpha degradation and NF-kappaB translocation, all of which are associated with co-stimulatory molecules expression. YC-1 inhibited the capacity of dendritic cell to activate allogenic T cells with an IC(50) value of 1.2+/-0.3 microM. YC-1-treated dendritic cells have mature phenotypes that exhibit up-regulated CCR7, enhanced IL-10 release and low phagocytosis activity in the presence of lipopolysaccharide. In conclusion, YC-1 inhibited the lipopolysaccharide-induced co-stimulatory molecular expression of dendritic cells by inhibiting Akt activation, IkappaBalpha degradation and NF-kappaB translocation. These inhibitory effects on co-stimulatory molecules suppressed the capacity of dendritic cells to activate allogenic T cells. Additionally, YC-1 treated dendritic cells exhibit the up-regulation of CCR7, enhanced IL-10 release and the down-regulation of phagocytosis in the presence of lipopolysaccharide. Accordingly, YC-1 might be a useful tool for evaluation of dendritic cells on autoimmune or allergic disease.     

Growth inhibition by the farnesyltransferase inhibitor FTI-277 involves Bcl-2 expression and defective association with Raf-1 in liver cancer cell lines

Farnesyltransferase inhibitors (FTIs) block the growth of tumor cells in vitro and in vivo with minimal toxicity toward normal cells. In general, inhibition of protein farnesylation results in G0/G1 cell cycle block, G2/M cell cycle arrest, or has no effect on cell cycle progression. One aspect of FTI biology that is poorly understood is the ability of these drugs to induce cancer cell growth arrest at the G2/M phase of cell cycle. In the present study, we investigated the effects of the farnesyltransferase inhibitor FTI-277 on two human liver cancer cell lines, HepG2 and Huh7. Treatment of these cells with FTI-277 inhibited Ras farnesylation in a dose-dependent manner. Both HepG2 and Huh7 cell growth was inhibited by FTI-277 and cells accumulated at the G2/M phase of the cell cycle. In HepG2 and Huh7 cells, FTI-277 induced an up-regulation of the cyclin-dependent kinase inhibitor p27(Kip1) without affecting the cellular levels of p53 and p21(Waf1). This event correlated with reduced activity of the cyclin-dependent kinase 2 and cyclin-dependent kinase 1. Moreover, increased expression of Bcl-2 protein was observed in HepG2 and Huh7 cells treated with FTI-277, and this was coincidental with reduced association between Raf-1 and Bcl-2. Finally, transient transfection of a dominant-negative Ras allele induced Bcl-2 expression and reduced Bcl-2/Raf-1 association demonstrating a requirement for Ras. Taken together, these findings show that increased expression of p27(Kip1) and Bcl-2 is concomitant with altered association between Ras, Raf-1 and Bcl-2 and suggest that this is responsible for the growth-inhibitory properties of FTI-277.