BACKGROUNDAngiopoietin-1 (Ang-1) is an endothelial-specific growth factor that can promote angiogenesis. Studies demonstrated that Ang-1 can inhibit apoptosis of umbilical endothelial cells, but so far little is known about its effects on apoptosis of microvascular endothelial cells. With the apoptotic model of murine-cerebral-derived microvascular endothelial cells (bEnd.3) induced by serum-free culture, we attempted to clarify the molecular mechanism of bEnd.3 apoptosis, particularly its relation to cytochrome C (Cyt C).

METHODSThe cultured microvascular endothelial cell strain, bEnd.3 cell, was employed. An apoptotic model of bEnd.3 was established by serum-free culture. Flow cytometry after Annexin labeling and PI staining were used to assess the apoptotic effects of Ang-1 on bEnd.3, and the expression of Bax/Bcl-2, caspase 8, caspase 3, and Cyt C were detected with Western blotting and ELISA.

RESULTSThe apoptotic rate of bEnd.3 cells after stimulation with Ang-1 (100 ng/L) in serum-free medium was significantly higher than that in control group. Ang-1 inhibited early-stage apoptosis more than late-stage apoptosis provided by propidium iodide (PI) and AnnexinV double staining. The inhibition of Ang-1 on bEnd.3 cell apoptosis was strengthened with the increase in concentration (0 - 400 ng/ml). Ang-1 could decrease the expression of Bax, caspase3 and 8, and increase that of Bcl-2. The results of ELISA indicated that Ang-1 significantly decreased CytC content in cytoplasm and increase that in mitochondria.

CONCLUSIONSAng-1 could inhibit bEnd.3 apoptosis induced by serum-free medium culture. The apoptosis was associated with decreased Bax expression, increased Bcl-2 expression, which result in Cyt C transferring from mitochondria to cytoplasm, and then caspases activation are reduced and cell apoptosis is suppressed.

Angiopoietin-1 ; pharmacology ; Animals ; Annexin A5 ; analysis ; Apoptosis ; drug effects ; Caspase 3 ; Caspase 8 ; Caspases ; analysis ; Cells, Cultured ; Cytochromes c ; physiology ; Endothelial Cells ; cytology ; drug effects ; Mice ; Microcirculation ; drug effects ; bcl-2-Associated X Protein ; analysis

BACKGROUND/OBJECTIVES: Although several recent studies have reported the anti-cancer effects of extracts or components of Citrus unshiu peel, which has been used for various purposes in traditional medicine, the molecular mechanisms for their effects remain unclear. In the present study, the anti-cancer activity of a water-soluble extract of C. unshiu peel (WECU) in MDA-MB-231 human breast carcinoma cells at the level of apoptosis induction was investigated. MATERIALS/METHODS: Cytotoxicity was evaluated using the MTT assay. Apoptosis was detected using DAPI staining and flow cytometry analyses. Mitochondrial membrane potential, reactive oxygen species (ROS) assay, caspase activity and Western blotting were used to confirm the basis of apoptosis. RESULTS: The results indicated that WECU-induced apoptosis was related to the activation of caspase-8, and -9, representative initiator caspases of extrinsic and intrinsic apoptosis pathways, respectively, and caspase-3 accompanied by proteolytic degradation of poly(ADP-ribose) polymerase and down-regulation of the inhibitors of apoptosis protein family members. WECU also increased the pro-apoptotic BAX to anti-apoptotic BCL-2 ratio, loss of mitochondrial membrane potential and cytochrome c release from mitochondria to cytoplasm. Furthermore, WECU provoked the generation of ROS, but the reduction of cell viability and induction of apoptosis by WECU were prevented when ROS production was blocked by antioxidant N-acetyl cysteine. CONCLUSIONS: These results suggest that WECU suppressed proliferation of MDA-MB-231 cells by activating extrinsic and intrinsic apoptosis pathways in a ROS-dependent manner.
Apoptosis* ; Blotting, Western ; Breast Neoplasms* ; Breast* ; Caspase 3 ; Caspase 8 ; Caspases, Initiator ; Cell Survival ; Citrus* ; Cysteine ; Cytochromes c ; Cytoplasm ; Down-Regulation ; Flow Cytometry ; Humans* ; Medicine, Traditional ; Membrane Potential, Mitochondrial ; Mitochondria ; Oxygen* ; Poly(ADP-ribose) Polymerases ; Reactive Oxygen Species ; Water*

PURPOSE : Several lines of evidence have indicated that deregulation of apoptosis is involved in the mechanism of cancer development. Caspase-8 activation plays a central role in the initiation phase of apoptosis, while caspase-7 is one of the main execution phase caspases of apoptosis. The aim of this study was to explore the possibility that genetic alterations of the caspase-8 and caspase-7 genes are involved in the development of human non-small cell lung cancer (NSCLC). MATERIALS AND METHODS : We have analyzed the entire coding region of both the caspase-7 and caspase-8 genes to detect the somatic mutations in 100 NSCLCs by using polymerase chain reaction (PCR)- single strand conformation polymorphism (SSCP). RESULTS : The PCR-SSCP analysis detected no mutations in the entire coding regions of both the caspase-7 and caspase-8 genes in the NSCLCs. CONCLUSION : The data presented here suggests that both the caspase-7 and caspase-8 genes may not be somatically mutated in human NSCLCs
Apoptosis ; Carcinoma, Non-Small-Cell Lung* ; Caspase 7* ; Caspase 8 ; Caspases ; Clinical Coding ; Humans ; Polymerase Chain Reaction

Chronic hypoxia has been associated with change in neurovascular behavior, mediated, in part, by erythropoietin (EPO). EPO, a hematopoietic growth factor, could act as a neurotrophic factor. In the present study, we investigated the characteristics of EPO and erythropoietin receptor (EPOR) expressions by cortical neuron in vivo and in vitro and tested the hypothesis that EPO serves protective functions under chronic hypoxia. E18, P5 and P7 mice for 3 days and primary cultured neurons for 6 days were incubated in hypoxic conditions consisted of a mixture of 10% O2, 5% CO2, 85% N2. To study expressions of EPO, EPOR, caspases, pAKT, pERK, and PARP, immunohistochemical stainning and western blotting were carried out. In addition to expressing EPO and EPOR under normoxic conditions, neurons increased their expression of EPO and EPOR under hypoxia. The effects of recombinant EPO appeared to be mediated via the phosphatidylinositol (PI) 3- kinase-AKT pathway, correlated directly with activation of caspase 3. Also recombinant EPO decreased expression of caspase 8, but not caspase 9. Finally, recombinant EPO decreased apoptosis of cultured neurons as evaluated by expression of PARP. These data support a role for EPO in maintenance of cortical neuron under chronic hypoxia.
Animals ; Anoxia* ; Apoptosis ; Blotting, Western ; Caspase 3 ; Caspase 8 ; Caspase 9 ; Caspases ; Erythropoietin ; Mice ; Neurons* ; Phosphatidylinositols ; Receptors, Erythropoietin

This study explored the effect and underlying mechanism of Stellera chamaejasme extract(SCE) on multidrug resistance of breast cancer. The chemotherapy-sensitive breast cancer cell line MCF-7 and adriamycin(ADR)-resistant cell line MCF-7/ADR were used as experimental subjects. MTT assay was used to detect cell proliferation activity. Pi staining was used to detect the cell cycle. 4',6-Diamidino-2-phenylindole, dihydrochloride(DAPI) staining and flow cytometry were used to detect apoptosis. Dansylcadaverine(MDC) staining and GFP-LC3B-Mcherry adenovirus transfection were used to detect autophagy. The protein expression of Bcl-2, Bax, caspase-9, caspase-3, LC3B, p62, and Beclin-1 was detected by Western blot. The results showed that SCE could significantly inhibit the proliferation of both sensitive and resistant breast cancer cell lines. The drug resistance factor was 0.53, which was significantly lower than 59 of ADR. Meanwhile, the proportion of sensitive/resistant cells in the G_0/G_1 phase increased significantly after SCE treatment. In addition, DAPI staining showed that a series of apoptosis phenomena such as nuclear pyknosis, staining deepening, and nuclear fragmentation appeared in sensitive/resistant cell lines after SCE administration. Moreover, the results of flow cytometry double staining showed that the proportion of apoptotic cells in sensitive/resistant cell lines increased significantly after SCE administration. Besides, Western blot showed that the protein expression levels of caspase-3, caspase-9, and Bcl-2 significantly decreased and the expression level of Bax protein significantly increased in both breast cancer cell lines after SCE administration. Furthermore, SCE could also increase the positive fluorescent spots after MDC staining and yellow fluorescent spots after GFP-LC3B-mcherry transfection, and up-regulate the expression levels of autophagy-related proteins LC3B-Ⅱ, p62, and Beclin-1 in breast cancer cells. In summary, SCE may play the role of anti-multidrug resistance by blocking the cell cycle of breast cancer multidrug-resistant cells, blocking autophagy flow, and ultimately interfering with the apoptosis resistance of drug-resistant cells.
Humans ; Female ; Breast Neoplasms/metabolism* ; MCF-7 Cells ; Caspase 3/metabolism* ; Caspase 9/metabolism* ; Beclin-1/pharmacology* ; Apoptosis ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Cell Proliferation

Mammalian cell is critically dependent on a continuous supply of oxygen. Even brief periods of oxygen deprivation can result in profound cellular damage. The aim of this study was to examine the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3E1 osteoblasts under hypoxic conditions (2% oxygen) resulted in apoptosis in a time-dependent manner, determined by DNA fragmentation assay and nuclear morphology, stained with fluorescent dye (Hoechst 33258) Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration-dependent manner. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases were involved in apoptosis, western blot analysis was performed using an anti-caspase-3 or 6 antibody. The 17-kDa protein, that corresponds to the active products of caspase-3 and the 20-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged lysates, in which the full length forms of caspase-3 and 6 were evident. With a time course similar to caspase-3 and 6 activation, hypoxic stress also caused the cleavage of Lamin A, typical of caspase-6 activity. In addition, the hypoxic stress elicited the release of cytochrome c into the cytosol during apoptosis. These findings suggested that the activation of caspases accompanied by a cytochrome c release in response to hypoxia was involved in apoptotic cell death in MC3T3E1 osteoblasts.
Anoxia* ; Apoptosis* ; Blotting, Western ; Caspase 3 ; Caspase 6 ; Caspases ; Cell Death ; Cytochromes c ; Cytosol ; DNA ; DNA Fragmentation ; Lamin Type A ; Osteoblasts* ; Oxygen ; Signal Transduction*

Glycoproteins isolated from fruit bodies and mycelial cultures of mushrooms exhibit anti-carcinogenic actions in human cancer cells and animal tumor cells by induction of apoptosis. Here, we report that isoflavone-conjugated glycoproteins (designate Gluvone), exhibit strong anti-carcinogenic effects on human breast cancer MCF-7 cells by induction of apoptosis. Gluvone with 9.4 kDa of molecular weight was isolated from submerged-liquid culture of Agaricus blazei mycelia (ABM) in soy flake-containing liquid medium. MCF-7 cells were incubated with various amounts of Gluvone (0~250 microM) for a period of 6 days. Gluvone exhibited anti-proliferative actions in a dose-dependent manner and 62% growth inhibition at 200 microM for 4 days relative to control. Hoechst 33258 staining analysis revealed that Gluvone induced formation of apoptotic bodies. Gluvone was associated with down-regulation of anti-apoptotic Bcl-2 protein expression as well as up-regulation of pro-apoptotic Bax protein expression. Gluvone treatment induced proteolytic activation of caspase-9 and caspase-3 through cytochrome c release from mitochondria to cytosol as well as concomitant degradation of poly (ADP-ribose) polymerase (PARP). In addition, Gluvone induced activation of caspase-8. Taken all together, these results indicate that the anti-proliferative effect of Gluvone is associated with induction of apoptotic cell death through the mitochondrial dysfunction pathway mediated by enhancement of Bax protein expression and suppression of Bcl-2 protein expression.
Agaricales ; Agaricus* ; Animals ; Anticarcinogenic Agents ; Apoptosis ; bcl-2-Associated X Protein* ; Bisbenzimidazole ; Breast Neoplasms ; Caspase 3 ; Caspase 8 ; Caspase 9 ; Cell Death ; Cytochromes c ; Cytosol ; Down-Regulation ; Fruit ; Glycoproteins* ; Humans ; Isoflavones* ; MCF-7 Cells ; Mitochondria ; Molecular Weight ; Up-Regulation

This study aims to investigate the effect and mechanism of saikosaponin D on the proliferation, apoptosis, and autophagy of pancreatic cancer Panc-1 cells. The cell counting kit(CCK-8) was used to examine the effects of 7, 10, 13, 16, 19, 22, 25, and 28 μmol·L~(-1) saikosaponin D on the proliferation of Panc-1 cells. Three groups including the control(0 μmol·L~(-1)), low-concentration(10 μmol·L~(-1)) saikosaponin D, and high-concentration(16 μmol·L~(-1)) saikosaponin D groups were designed. The colony formation assay was employed to measure the effect of saikosaponin D on the colony formation rate of Panc-1 cells. The cells treated with saikosaponin D were stained with hematoxylin-eosin(HE), and the changes of cell morphology were observed. Hoechst 33258 fluorescent staining was used to detect the effect of saikosaponin D on the cell apoptosis. The autophagy staining assay kit with MDC was used to examine the effect of saikosaponin D on the autophagy of Panc-1 cells. Western blot and immunocytochemistry(ICC) were employed to examine the effect of saikosaponin D on the expression levels and distribution of B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), cysteine-aspartic acid protease-3(caspase-3), cleaved caspase-3, autophagy-associated protein Beclin1, microtubule-associated protein light chain 3(LC3), protein kinase B(Akt), phosphorylated protein kinase B(p-Akt), mammalian target of rapamycin(mTOR), and phosphorylated mammalian target of rapamycin(p-mTOR). The results showed that compared with the control group, saikosaponin D decreased the proliferation rate of Panc-1 cells in a dose-dependent and time-dependent manner. The colony formation rate of the cells significantly decreased after saikosaponin D treatment. Compared with the control group, the cells treated with saikosaponin D became small, accompanied by the formation of apoptotic bodies. The saikosaponin D groups showed increased apoptosis rate and autophagic vesicle accumulation. Compared with the control group, saikosaponin D up-regulated the expression of Bax, cleaved caspase3, Beclin1, LC3Ⅱ/LC3Ⅰ and down-regulated the expression of Bcl-2, caspase-3, p-Akt/Akt, and p-mTOR/mTOR. In addition, these proteins mainly existed in the cytoplasm. In conclusion, saikosaponin D can inhibit the proliferation and induce the apoptosis and autophagy of Panc-1 cells via inhibiting the Akt/mTOR pathway.
Humans ; Proto-Oncogene Proteins c-akt/genetics* ; Caspase 3 ; bcl-2-Associated X Protein ; Beclin-1/pharmacology* ; Cell Line, Tumor ; TOR Serine-Threonine Kinases/genetics* ; Apoptosis ; Pancreatic Neoplasms/drug therapy* ; Caspases ; Autophagy

AIMTo study the antitumor mechanism of 3-bromopropionylamino benzoylurea (JIMB01) on leukemia and lymphoma.

METHODSThe antitumor effects of JIMB01 in cell culture was detected by MTT staining. JIMB01-induced apoptosis in leukemia and lymphoma cells was tested by Giemsa staining, fluorescent Hoechst33258 staining, as well as DNA gel electrophoresis. Cell cycle was analyzed by flow cytometry. JIMB01-induced Bcl-2 phosphorylation in CEM cell lines was detected by Western blot methods. The activities of caspase-3 and caspase-8 were determined by colorimetric protease assay and that of caspase-9 was determined by fluorescent intensity.

RESULTSThis compound showed antiproliferative activities in a panel of nine human leukemia and lymphoma cell lines with IC50 values in the range of 0.25 micromol x L(-10 to 0. 51 micromol x L(-1). Morphological observation and cell cycle analysis indicated that CEM cells were blocked at mitosis phase by JIMB01. The fluorescent Hoechst33258 staining showed apoptotic nuclear degradation dispersed in the cytoplasm of CEM cells exposed to JIMB01 at 0. 80 micromol x L(-1) for 24 h. DNA degradation in the form of a multiple-unit DNA ladder was clearly demonstrated in CEM leukemia cells treated with JIMB01 at 0.15 micromol x L(-1) or higher for 24 h using agarose gel electrophoresis. Bcl-2 phosphorylation became visible, in Western blot, within 6 h in CEM cells treated with JIMB01 at 0.15 micromol x L(-1) or higher for 24 h. JIMB01 increased the activities of caspase-3, -8 and -9 in CEM cells; DEVD-fmk, a caspase-3 inhibitor, inhibited the cytotoxicity of JIMB01 in CEM leukemia cells.

CONCLUSIONThe antitumor mechanism of JIMB01 is that JIMB01 may induce tumor cell apoptosis through Bcl-2 phosphorylation and then caspase passway.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; Caspase 8 ; Caspase 9 ; Caspases ; metabolism ; Cell Division ; drug effects ; DNA Fragmentation ; HL-60 Cells ; Humans ; Leukemia, T-Cell ; enzymology ; metabolism ; pathology ; Lymphoma, B-Cell ; pathology ; Phosphorylation ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Tumor Cells, Cultured ; U937 Cells ; Urea ; analogs & derivatives ; pharmacology

PURPOSE: Reactive oxygen species have been recognized as a common signaling mediator in diverse stimuli-induced apoptosis and hydrogen peroxide is a natural one of those reactive oxygen species. This study was performed to investigate the role of caspases in hydrogen peroxide-induced apoptosis of HL 60 cells. METHODS: Apoptosis was induced in HL 60 cells by treating 50microM hydrogen peroxide for 2, 4, and 6 hrs and induction of apoptosis was confirmed by flow cytometry and DNA fragmentation analysis. Caspase substrate assay was used to show the activity of caspases and then protein levels of caspase and its substrate were analyzed using immunoblotting. RESULTS: During the apoptosis, caspase substrates assay showed the increased activity of caspase-3, -7, -10, but not that of caspase-8 nor caspase-9, and immunoblotting analysis showed decreasing procaspase-3 protein with the progression of apoptosis. Furthermore, with progression of apoptosis, analysis of caspase substrates showed retinoblastoma protein decreased while cleaved 89kD fragment of poly (ADP-ribosyl) polymerase protein increased. CONCLUSION: These results suggest that hydrogen peroxide-induced apoptosis in HL 60 cells is not associated with the activation of caspase-8 nor caspase-9. Rather, caspase-3 is directly activated and responsible for hydrogen peroxide-induced apoptosis of HL 60 cells.
Apoptosis* ; Caspase 3* ; Caspase 8 ; Caspase 9 ; Caspases ; DNA Fragmentation ; Flow Cytometry ; HL-60 Cells* ; Humans* ; Hydrogen Peroxide ; Hydrogen* ; Immunoblotting ; Leukemia* ; Reactive Oxygen Species ; Retinoblastoma Protein