beta-Sitosterol induces G2/M arrest, endoreduplication, and apoptosis through the Bcl-2 and PI3K/Akt signaling pathways

β-Sitosterol (SITO) is a potentially valuable candidate for cancer chemotherapy, however the cellular and molecular mechanisms responsible for its anti-cancer activity are unknown. Therefore, we attempted to elucidate the mechanisms responsible for SITO-induced anti-proliferation in human leukemia cells. Treatment with SITO increased caspase-3 activation and DNA fragmentation in U937 and HL60 cells. This effect was associated with significant G₂/M arrest and endoreduplication. We also demonstrated that SITO treatment significantly increases levels of polymeric -tubulin and promoted microtubule polymerization. We next elucidated that ectopic expression of Bcl-2 accelerates endoreduplication in U937 cells. Furthermore, the specific Bcl-2 inhibitor, HA14-1, prevented endoreduplication through G₂ phase arrest. Interestingly, SITO treatment did not significantly promote endoreduplication or decrease cell viability in Bcl-2 null K562 cells. SITO treatment also induced a gradual increase of phosphatidyl-inositol 3-kinase (PI3K) and Akt phosphorylation. Treatment with the selective PI3K/Akt inhibitor LY29004 completely blocked endoreduplication and apoptosis in the presence of SITO. In addition, treatment with SITO-induced phosphorylation of extracellular signal-regulated protein kinase (ERK), however significance of ERK activation in the execution of apoptosis and endoreduplication is unknown. These results suggest that SITO induces endoreduplication by promoting spindle microtubule dynamics through the Bcl-2 and PI3K/Akt signaling pathways.     

Bcl-2 overexpression attenuates resveratrol-induced apoptosis in U937 cells by inhibition of caspase-3 activity

Resveratrol has been shown to induce anti-proliferation and apoptosis of human cancer cell lines. In the present study, we determined the effect of high intracellular levels of the anti-apoptosis protein Bcl-2 on caspase-3 activation, PLC-gamma1 degradation and cytochrome c release during resveratrol-induced apoptosis. For this, we used U937/vector and U937/Bcl-2 cells, which were generated by transfection of the cDNA of the Bcl-2 gene. As compared with U937/vector, U937/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment with 60 or 100 microM resveratrol for 24 h produced morphological features of apoptosis and DNA fragmentation in U937/vector cells, respectively. This was associated with caspase-3 activation and PLC-gamma1 degradation. In contrast, resveratrol-induced caspase-3 activation and PLC-gamma1 degradation and apoptosis were significantly inhibited in U937/Bcl-2 cells. Bcl-2 overexpressing cells exhibited less cytochrome c release and sustained expression levels of the IAP proteins during resveratrol-induced apoptosis. In addition, these findings indicate that Bcl-2 inhibits resveratrol-induced apoptosis by a mechanism that interferes with cytochrome c release and activity of caspase-3 that is involved in the execution of apoptosis.     

咖啡因促进受照肿瘤细胞凋亡的研究

目的：探讨肿瘤细胞受照后Ｇ２／Ｍ期阻滞和凋亡的关系及调控。方法：以Ｋ５６２细胞为对象,用流式细胞仪,形态学,ＤＮＡ电泳和凋亡蛋白２．７（ＡＰＯ２．７）等方法检测细胞周期和凋亡。结果：（１）２０Ｇｙγ射线照射Ｋ５６２细胞后引起Ｇ２／Ｍ期阻滞,４８ｈＧ２／Ｍ期比例为７１．２％,流式细胞仪,形态学和ＡＰＯ２．７检测凋亡比例分别为２．６％,２．０％±１．１Ａ％和２２．５％。（２）照前加入１０ｍｍｏｌ／Ｌ咖     

SP600125对D-氨基葡萄糖衍生物诱导Eca-109细胞凋亡的影响

目的:观察特异性JNK抑制剂[specificc-junNH2terminalproteinkinase(JNK)inhibitor]SP600125对D-氨基葡萄糖衍生物2-(3-羧基-1-丙酰氨基)-2-脱氧-D-葡萄糖{[2-(3-carboxy-1-oxopropyl)a-mino-2-deoxy-D-Glucose],COPADG}诱导Eca-109细胞凋亡的影响并探讨COPADG诱导Eca-109细胞凋亡的潜在分子机制。方法:体外培养Eca-109细胞,用COPADG及SP600125对细胞进行处理。细胞间接免疫荧光染色观察P-JNK蛋白表达的改变,倒置相差显微镜观察细胞形态学变化;MTT检测不同时间点的细胞活性;流式细胞术检测细胞凋亡率。结果:经SP600125处理后,COPADG诱导的Eca-109细胞P-JNK蛋白表达明显减弱,同时,COPADG诱导的Eca-109细胞凋亡率明显减低,细胞增殖抑制率下降明显,与COPADG单独作用组之间比较差异有统计学意义。结论:SP600125对D-氨基葡萄糖衍生物CO-PADG诱导Eca-109细胞凋亡具有抑制作用,并间接证明JNK信号转导通路在COPADG诱导Eca-109细胞凋亡过程中发挥着重要作用。     

辐射诱发肿瘤细胞增殖抑制和凋亡的相关研究

目的 探讨不同辐射敏感性的肿瘤细胞受照后G2/M期阻滞和凋亡发生的关系。为提高肿瘤放射治疗效果提供理论依据。方法 以人早幼粒白血病细胞株HL-60、人T淋巴细胞性白血病细胞系CEM和人红白血病细胞系K562细胞为对象,采用形态学观察、DNA琼脂糖凝胶电泳和流式细胞仪等方法检测细胞周期的改变和凋亡的发生。结果 辐射敏感的HL-60和CEM细胞受照后首先发生G2/M期阻滞,然后在阻滞退出过程中或之后发生凋亡;辐射耐受的K562细胞受照后只发生G2/M期阻滞,不发生凋亡;照射并加入咖啡因（CAF）,抑制3种细胞的G2/M期阻滞,促进凋亡;照射并加入佛波酯（TPA）,增加HL-60和CEM细胞的G2/M期阻滞,抑制凋。结论 辐射诱发肿瘤细胞的凋亡与G2/M期阻滞有关,用药物调控G2/M期阻滞可影响辐射所致的凋亡。     

Caspase-3 Activation Is Not Responsible for Vinblastine-induced Bcl-2 Phosphorylation and G2/M Arrest in Human Small Cell Lung Carcinoma Ms-1 Cells

Vinblastine arrests cells in the G2/M phase of the cell cycle and subsequently induces cell death by apoptosis. We found that treatment of cells with vinblastine induced phosphorylation of Bcl-2, resulting in the dissociation of Bcl-2 and Bax. Moreover, vinblastine-induced apoptosis was suppressed by an inhibitor of caspase-3, Ac-DEVD-CHO; and a 17-kDa active fragment of caspase-3 was detected following vinblastine treatment, suggesting that caspase-3 is involved in vinblastine-induced apoptosis. However, Ac-DEVD-CHO affected neither vinblastine-induced Bcl-2 phosphorylation nor vinblastine-induced G2/M arrest. Vinblastine caused G2/M arrest prior to apoptosis, whereas vinblastine-induced apoptosis was not dependent on the duration of the G2/M phase. Thus, vinblastine-induced apoptosis might be mediated by the phosphorylation of Bcl-2, resulting in Bcl-2 inactivation, and by subsequent activation of caspase-3.     

蛋白酶体抑制剂MG132诱导HL-60细胞凋亡前G2/M期阻滞及机制

背景和目的:蛋白酶体(proteasome)抑制剂能够诱导多种肿瘤细胞凋亡,是一种潜在的有应用前景的抗肿瘤剂.本研究旨在探讨蛋白酶体抑制剂MGl32(Z-Leu-Leu-Leu-CHO)诱导白血病细胞HL-60凋亡和C2/M期阻滞的机制.方法:采用荧光显微镜观察、流式细胞术和免疫印迹研究测定MG132诱导HL-60细胞凋亡和周期阻滞及机制.结果:2μmol/L的MG132能够有效地诱导HL-60细胞凋亡,用药后24 h就显现有细胞凋亡;在MG132诱导HL-60细胞凋亡出现之前有一个明显的G2/M期阻滞,加MG132后12 h时G2/M期时相百分比为63.42±2.02;24 h时加MG132组细胞凋亡为16.67±1.48,与对照组G2/M期时相百分比为7.29±3.01及细胞凋亡为0相比,两者之间有显著性差别(P＜0.01);咖啡因CAF能够减少MG132诱导HL-60细胞出现的G2/M期阻滞,同时也减少凋亡细胞的比例;细胞周期检查点的负调控因子p21waf/cip1蛋白在加MG132处理后3 h有明显的表达,但并未能检测到p53和p27蛋白.结论:MG132诱导HL-60细胞凋亡之前有一个明显的G2/M期阻滞,p21蛋白表达明显上调提示:是p21waf/cip1而不是p53或其同源蛋白参与了其中的调控.     

The activation of ERK1/2 via a tyrosine kinase pathway attenuates trail-induced apoptosis in HeLa cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) serves as an extracellular signal that triggers apoptosis in tumor cells. To characterize the molecular events involved in TRAIL-induced apoptotic signaling, we investigated the role of extracellular signal-regulated kinase 1/2 (ERK1/2) in HeLa cell death. Here we show that TRAIL-activated ERK1/2 through a tyrosine kinase-dependent pathway, subsequently elevated anti-apoptotic Bcl-2 protein levels. ERK1/2 inhibition with PD98059 promoted apoptotic cell death through the downregulation of ERK1/2 activity and Bcl-2 protein levels. Moreover, tyrosine kinase inhibition with Genistein in TRAIL-induced apoptosis effectively attenuated ERK1/2 activity and enhanced apoptotic cell death. Taken together, our results indicate that ERK1/2 activation via tyrosine kinase pathway plays a protective role as the cellular defense mechanism through the upregulation of Bcl-2 protein levels in TRAIL-induced apoptosis.     

Petrotetrayndiol A induces cell cycle arrest and apoptosis in SK-MEL-2 human melanoma cells through cytochrome c-mediated activation of caspases

We investigated the possible mechanisms by which petrotetrayndiol A, a polyacetylene from the sponge Petrosia sp., exerts its anti-proliferative activity in cultured SK-MEL-2 human melanoma cells. Petrotetrayndiol A-treated SK-MEL-2 cells showed growth inhibition and induction of apoptosis in a dose-dependent manner as measured by MTT assay, fluorescent microscopy and flow cytometric analysis. Flow cytometric analysis revealed that petrotetrayndiol A resulted in G2/M arrest in the cell cycle progression which was associated with a marked decrease in the protein expression of cyclin B1 and its activating partner Cdc2 with concomitant inductions of p21WAF1/CIP1. The increase in apoptosis was associated with a dose-dependent up-regulation of cytosolic factor, such as Bax and release of cytochrome c, and down-regulation of Bcl-2. We also observed activation of caspase-9 and caspase-3, DNA ladder formation, proteolytic degradation of poly(ADP-ribose)-polymerase (PARP), and selective down-regulation of cIAP-1. The apoptotic manifestations, such as PARP cleavage and DNA fragmentation, were abolished in the presence of the tripeptide caspase inhibitor z-VAD-fmk and a caspase-3-specific inhibitor Ac-DEVD-cho. Our data thus demonstrate that petrotetrayndiol A-induced apoptosis and growth inhibition of SK-MEL-2 cells is dependent on caspase activation.     

Regulation of signaling pathways involved in lupeol induced inhibition of proliferation and induction of apoptosis in human prostate cancer cells

Prostate cancer (PCa) is the most frequently diagnosed noncutaneous cancer and the leading cause of cancer related deaths in men in the United States and many other Asian countries. Dietary factors are considered as a strategic agent to control the risk of PCa. Lupeol, a triterpene, present in fruits and medicinal plants, has been shown to possess many pharmacological properties including anticancer effects. Here, effect of lupeol on cell proliferation and cell death was evaluated using human PCa cells, PC-3. In MTT assay, lupeol inhibited the cell proliferation (12-71%) in dose (50-800 microM) and time dependent manner. Flow-cytometric analysis of cell-cycle revealed that an antiproliferative effect of lupeol (400-600 microM) is associated with an increase in G(2)/M-phase arrest (34-58%). RT-PCR analysis showed that lupeol-induced G2/M-phase arrest was mediated through the inhibition of cyclin regulated signaling pathway. Lupeol inhibited the expression of cyclin B, cdc25C, and plk1 but induced the expression of 14-3-3sigma genes. However no changes were observed in the expression of gadd45, p21(waf1/cip1) and cdc2 genes. Results of western blot showed that lupeol regulates the phosphorylation of cdc2 (Tyr15) and cdc25C (Ser198). Further, on increase of lupeol exposure to PC-3 cells an induction of apoptosis was recorded, which was associated with upregulation of bax, caspase-3, -9, and apaf1 genes and down regulation of antiapoptotic bcl-2 gene. The role of caspase-induced apoptosis was confirmed by increase in reactive oxygen species, loss of mitochondrial membrane potential followed by DNA fragmentation. Thus, our study suggests that lupeol possess novel antiproliferative and apoptotic potential against PCa.     

Monitoring apoptosis and Bcl-2 on circulating tumor cells in patients with metastatic breast cancer

BackgroundEnumeration of circulating tumor cells (CTC) from whole blood permits monitoring of patients with breast carcinoma. Analysis of apoptosis & Bcl-2 expression in CTC might add additional prognostic and predictive information. We estimated the degree of these markers in CTC from patients being treated for metastatic breast cancer.MethodsEighty-three evaluable patients initiating a new therapy for metastatic breast cancer were enrolled. Whole blood was collected at baseline, at one of three short term time windows (24, 48, or 72 h) after initiating treatment, and at first follow-up (3–5 weeks). CTC were isolated, enumerated, and expression of M30 and Bcl2 was determined using the CellSearch^® System.ResultsAt baseline, window, and 3–5 weeks post-treatment, 41/80 (51%), 40/80 (50%) and 21/75 (28%) patients had ≥5 CTC, respectively. At baseline, the proportion of CTC-apoptosis (M30) was inversely correlated with CTC number, and modestly inversely correlated with CTC-Bcl-2. As expected, higher CTC levels at baseline or first follow-up were associated with worse prognosis. Surprisingly, in patients with elevated CTC, higher levels of CTC-apoptosis were associated with worse prognosis, while higher CTC-Bcl-2 levels correlated with better outcomes.ConclusionsCTC apoptosis and expression of Bcl-2 can be analytically determined in patients with metastatic breast cancer and may have biological and clinical implications. Characterization of CTC for these and other markers could further increase the utility of CTC monitoring patients in clinical investigations of new anti-neoplastic agents.     

Actinonin induces apoptosis in U937 leukemia cells

S100A4 has multiple functions in cell cycle progression and cell motility, and has been implicated in cancer invasion. In this study, we examined the expression of S100A4, E-cadherin and its related proteins in oral squamous cell carcinoma (SCC) cell lines with different invasive phenotypes, grade 4C and 4D. Furthermore, grade 4C OSC-19 cells expressing E-cadherin were transfected with S100A4-expression vector and the expression of E-cadherin-related proteins in the stable clone was examined to elucidate the relationship between S100A4 and E-cadherin. Constitutive over-expression of S100A4 in stable transformant of OSC-19 (OSC-19/S100A4) cells led to down-regulation of E-cadherin and β-catenin. Furthermore, grade 4D invasive cell lines (HOC313 and TSU) expressing S100A4 mRNA did not express E-cadherin, P-cadherin, and β-catenin, while γ-catenin protein was only weakly expressed. Thus, the mRNA expression of E-cadherin was reversely correlated with S100A4 expression in oral SCCs. Interestingly, vascular endothelial growth factor-C was up-regulated in OSC-19/S100A4 cells. In summary, S100A4-mediated regulation of E-cadherin expression may play an important mechanism in invasion and metastasis of oral SCC.     

Induction of apoptosis in pediatric acute lymphoblastic leukemia (ALL) cells by the therapeutic opioid methadone and effective synergy with Bcl-2 inhibition

Although recent decades have seen a significant improvement in the treatment outcome of leukemia in the pediatric population, those who are treated for relapsed disease still face significant morbidity and mortality. However, current salvage regimens are often assembled with agents that have similar mode of activity as the chemotherapeutics used in the initial treatment. Hence, novel therapeutic agents that are capable of distinct and diverse mechanisms of activity in, now resistant, leukemia cells are of great interest. We have investigated the opioid agonist methadone for its anti-leukemic activity, initially reported in studies with cell lines derived from adult patients. Our findings show that, compared to normal cells, methadone has enhanced cytotoxicity against specimens and cell lines established from refractory childhood leukemia. In addition, methadone's activity synergized with that of the anti-Bcl-2 agent ABT-737 and was characterized by the induction of distinct changes in tumor cell mitochondria. Data presented also identify biological correlates and a potential mechanism for methadone activity by its effects on Mcl-1 and other members of the apoptosis cascade. We provide mechanistic data for the therapeutic potential of a family of agents that is largely unexplored for anti-leukemic activity.     

rRNA synthesis inhibitor,CX-5461, activates ATM/ATR pathway in acute lymphoblastic leukemia,arrests cells in G2 phase and induces apoptosis

Ribosome biogenesis is a fundamental cellular process and is elevated in cancer cells. As one of the most energy consuming cellular processes, it is highly regulated by signaling pathways in response to changing cellular conditions. Many of the regulators of this process are aberrantly activated in various cancers. Recently two novel rRNA synthesis inhibitors, CX-5461 and BMH-21, have been shown to selectively kill cancer cells while sparing normal cells. Here, we tested the effectiveness of pre-rRNA synthesis inhibitor CX-5461 on acute lymphoblastic leukemia cells with different cytogenetic abnormalities. Acute lymphoblastic leukemia cells are more sensitive to rRNA synthesis inhibition compared to normal bone marrow cells. CX-5461 treated cells undergo caspase-dependent apoptosis independent of their p53 status. More-over, CX5461, activates checkpoint kinases and arrests cells in G2 phase of cell cycle. Finally, overcoming this G2 arrest by inhibiting ATR kinase leads to robust cell killing. These results show that CX-5461 can be even more potent in combination with ATR inhibitors.     

Bcl-2反义寡核苷酸增强阿糖胞苷诱导原代白血病细胞凋亡的研究

背景与目的:有研究证实,针对bcl-2mRNA翻译起始区和蛋白编码区的2个有效反义作用靶点的反义寡核苷酸能增强HL-60和K562细胞对阿糖胞苷(Ara-C)、柔红霉素、足叶乙甙的敏感性。本研究观察这两个新靶点的反义寡核苷酸对Ara-C诱导原代培养的急性白血病(AL)、慢性淋巴细胞白血病(CLL)细胞凋亡的影响。方法:用细胞记数法观察细胞的生存情况;免疫荧光标记法通过流式细胞仪检测细胞Bcl-2蛋白水平;用姬姆萨染色法观察并用流式细胞仪检测细胞凋亡。结果:靶向bcl-2mRNA翻译起始区与靶向蛋白编码区的两个反义寡核苷酸分别与Ara-C联合作用AL、CLL细胞48h,细胞的活性受到明显的抑制,分别同无关寡核苷酸(NS-ODN)联合Ara-C组、单用Ara-C组进行比较,差异有显著性(P<0.05)。这两个不同靶点的反义寡核苷酸分别与Ara-C联用均能明显下调AL、CLL细胞Bcl-2蛋白的表达,并且联合作用AL、CLL细胞48h的凋亡细胞百分率分别与NS-ODN联合Ara-C组、单用Ara-C组进行比较,差异有显著性(P<0.05)。与靶向bcl-2mRNA翻译起始区的反义寡核苷酸比较,靶向蛋白编码区的反义寡核苷酸提高AL细胞对Ara-C的敏感性作用要强些(P<0.05)。结论:针对bcl-2mRNA翻译起始区和蛋白编码区两个靶点的反义寡核苷酸能增强Ara-C诱导AL、CLL细胞的凋亡。     

Butein induces G2/M phase arrest and apoptosis in human hepatoma cancer cells through ROS generation

We investigated the molecular effects of 3,4,2′,4′-tetrahydroxychalcone (butein) treatment in two human hepatoma cancer cell lines–HepG2 and Hep3B. Butein treatment inhibited cancer cell growth by inducing G₂/M phase arrest and apoptosis. Butein-induced G₂/M phase arrest was associated with increased ATM, Chk1, and Chk2 phosphorylations and reduced cdc25C levels. Additionally, butein treatment enhanced inactivated phospho-Cdc2 levels, reduced Cdc2 kinase activity, and generated reactive oxygen species (ROS) that was accompanied by JNK activation. The extent of butein-induced G₂/M phase arrest significantly decreased following pretreatment with N-acetyl-l-cysteine or glutathione and following JNK phosphorylation reduction by SP600125. Both N-acetyl-l-cysteine and glutathione also decreased butein-mediated apoptosis. Taken together, these results imply a critical role of ROS and JNK in the anticancer effects of butein.     

Small-molecule Bcl-2 antagonists as targeted therapy in oncology

Dynamic protein–protein interactions between proapoptotic and pro-survival Bcl-2 family members regulate outer-mitochondrial membrane permeabilization and cytochrome c release, key events in the path to apoptosis. Their relative levels often dictate the fate of a cell following an apoptotic stimulus. However, in cancer cells, the pro-survival Bcl-2 family members are frequently upregulated, thereby creating a constitutive block to apoptosis and resulting in continued cell survival under conditions that normally result in cell death. Because many chemotherapeutics used to treat cancer also trigger apoptosis, this upregulation of pro-survival members also contributes to resistance to conventional cancer therapies. Strategies that inactivate pro-survival Bcl-2 family members therefore suggest a means by which this downstream block in apoptosis can be alleviated, resulting in the selective killing of malignant cells. Here, we outline the progress of three small-molecule Bcl-2 antagonists that have advanced into clinical evaluation.     

Vitexicarpin Induces Apoptosis in Human Prostate Carcinoma PC-3 Cells through G2/M Phase Arrest

Vitexicarpin (3’, 5-dihydroxy-3, 4’, 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from ViticisFructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinesemedicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However,there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was toexamine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTTstudies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an IC50~28.8 μM. Hoechst33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. Theresults indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cyclearrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosiswas associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic proteinBcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Ourfindings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.     

Involvement of Bcl-2 family, cytochrome c and caspase 3 in induction of apoptosis by beauvericin in human non-small cell lung cancer cells

Beauvericin (BEA), a cyclic hexadepsipeptide from Codyceps cicadae, possesses anti-convulsion, anti-arrhythmia, sedation, and anti-tumor activities. It has been reported that BEA induces apoptosis in several cancer cell lines. However, the molecular mechanism underlying the BEA-induced apoptotic process is not yet clearly understood. In the present study, the intracellular signaling pathways of BEA-induced apoptosis in human non-small cell lung cancer (NSCLC) A549 cells were investigated using morphological analysis and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) technique. In this study, BEA-induced apoptosis in human NSCLC A549 cells demonstrated a BEA concentration- and treatment time-dependent manner. This BEA-induced apoptosis in human NSCLC A549 cells was also accompanied by the up-regulation of Bax, Bak, and p-Bad and down-regulation of p-Bcl-2, but no effect on the levels of Bcl-X_L or Bad proteins. Moreover, the BEA treatment resulted in a significant reduction of mitochondrial membrane potential, increase in the release of mitochondrial cytochrome c (cyt c), and activation of caspase 3. Furthermore, treatment with caspase 3 inhibitor (z-DEVD-fmk) was capable to prevent the BEA-induced caspase 3 activity and cell death. These results clearly demonstrate that the induction of apoptosis by BEA involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cyt c, and caspase 3, they all participate in BEA-induced apoptotic process in human NSCLC A549 cells.