PURPOSE: Evidence exists that dysregulation of apoptosis is involved in the pathogenesis of cancer development. The Bcl-XL/Bcl-2-associated death promoter (BAD), a member of the Bcl-2 family, is a critical regulatory component of the intrinsic cell-death pathway that exerts its pro-apoptotic effect upon heterodimerization with anti-apoptotic proteins Bcl-2 and Bcl-XL. Expression of the BAD protein has been reported in several cancer types, but not in stomach cancer. The aim of this study was to explore the expression status of the BAD protein in gastric carcinomas. MATERIALS AND METHODS: In the current study, we analyzed the expression of the BAD protein in 60 advanced gastric adenocarcinomas by using immunohistochemistry and a tissue microarray approach. RESULTS: Immunopositivity (defined as > or =30%) was observed for the BAD protein in 57 (95%) of the 60 cancers. Normal gastric mucosal cells showed weaker expressions of the BAD protein than gastric carcinomas. CONCLUSION: Taken together, these results suggest that stomach cancer cells in vivo may need BAD protein expression for apoptosis. Also, the higher expression of the BAD protein in stomach cancer cells than in normal gastric mucosal cells suggests that apoptosis might be easily triggered in susceptible stomach cancer cells, thereby producing selective pressure to make more apoptosis-resistant cells during tumor development.
Adenocarcinoma ; Apoptosis ; Apoptosis Regulatory Proteins ; bcl-Associated Death Protein* ; Humans ; Immunohistochemistry ; Stomach Neoplasms

This work describes the pharmacological inhibition by KR 31378 and its acetyl metabolite, KR 31612, of the apoptotic cell death induced by H2O2 in the A7r5 cells. Exposure of A7r5 cells to H2O2 (0.5 mM) induced a concentration-dependent cytotoxicity in association with oligonucleosomal DNA fragmentation. H2O2-induced cell death was potently suppressed by KR 31378, KR 31612, alpha-tocopherol or trolox. Additionally, the apoptotic death of A7r5 cells (DNA ladders on electrophoresis) was also strongly suppressed by KR 31378 and KR 31612, but to a less degree by alpha-tocopherol and trolox. As a mechanistic study, incubation with H2O2 markedly showed a decreased Bcl-2 level and, in contrast, increased Bax protein and cytochrome C release, which were significantly and concentration-dependently reversed by KR 31378 and KR 31612 as well as by alpha-tocopherol and trolox. KR 31378 and alpha-tocopherol significantly reduced lipid peroxidation in accordance with reduced intracellular ROS and peroxyl radical. These results suggest that KR 31378 has a therapeutic potential against the apoptotic injury via mediation of antioxidative stress.
alpha-Tocopherol ; bcl-2-Associated X Protein ; Cell Death ; Cytochromes c ; DNA Fragmentation ; Lipid Peroxidation ; Negotiating

BACKGROUND: Conventional treatment for mesothelioma is largely ineffective. We evaluated the novel approach of adenoviral gene transfection of PTEN gene in mesothelioma cancer cell lines, inflammatory and epithelial subtype, which are sensitive to adenoviral p53. MATERIAL AND METHOD: Binary adenoviral PTEN and LacZ (Ad/GT-LacZ and Ad/GV16) vectors were used for transduction of the mesothelioma cell lines, REN (p53 sensitive). Protein levels were determined by Western blotting assay. Apoptosis was assessed by fluorescence-activated cell sorter analysis of subdiploid populations. Cell viability was determined with the XTT assay. Statistical analysis was performed with analysis of variance and the Student t test. RESULT: 72 hours after the treatment of adenoviral PTEN gene, cell killing were 32.9% for REN compared to control cell (2.5%) at MOI of 20. Also we observed the over-expression of proapoptotic protein, bax and decreased expression of bcl-2 protein in REN cells. But the expression of BCL-xl, Bak, Bad proteins were not altered. CONCLUSION: Adenovirus Pten-mediated overexpression of the Bax gene induces apoptosis and decreased cellular viability in p53-sensitive mesothelioma cells. These data suggest that the transfection of PTEN gene may represent a alternative gene therapy strategy to treat mesothelioma.
Adenoviridae ; Apoptosis ; bcl-Associated Death Protein ; Blotting, Western ; Cell Death ; Cell Line ; Cell Survival ; Genetic Therapy ; Homicide ; Humans ; Mesothelioma* ; Transfection

BACKGROUND: Proteins of the Bcl-2 family are intracellular membrane-associated proteins that regulate programmed cell death either positively or negatively by as yet unknown mechanism. Bcl-2 family proteins have an antiapoptotic function, such as the Bcl-2, the long form of Bcl-x and Mcl-l, or a proapoptotic function, like the short form of Bcl-x and Bax. To investigate the potential role of Bcl-2 family proteins in thyroid tumorigenesis, the authors examined the pattern of expression of the Bel-2 family proteins in various thyroid neoplasms. METHODS: Bcl-2 family proteins, including Bcl-2, Bcl-x, Mcl-1 and Bax proteins were immunohistochemically stained in 57 cases of various thyroid neoplasms using formalin-fixed and paraffin embedded tissues; 18 cases of papillary carcinoma, 6 cases of medullary carcinoma, 4 cases of anaplastic carcinoma, 10 cases of follicular adenoma, 9 cases of adenomatous goiter, and 10 autopsy cases of fetal thyroid galnd. The intensity and frequency of the immunostaining were evaluated with the program of Image-Pro Plus Version 3.0 for image analysis. RESULT: Consistent expression of Bcl-2, Mcl-1, and Bax proteins were present in the surrounding normal thyroid tissue, however the expression of Bcl-x protein was not observed. Compare to the expression patterns of adenomatous goiter, and fetal and surrounding normal thyroid tissues, papillary and anaplastic carcinomas showed the decreased Bcl-2 and increased Bcl-x protein expressions(p (0.05). Medullary carcinoma revealed the increased Bcl-x protein expression only(p 0.05). CONCLUSION: These data suggest that combined patterns of decreased Bcl-2 and increased Bcl-x protein expressions may eontribute to the carcinogenesis of thyroid cancers originated from thyroid follicular cells, and an increased expression of Bcl-x protein may be related to the pathogenesis of medullary carcinoma from parafollicular C cells.
Adenoma ; Autopsy ; bcl-2-Associated X Protein ; bcl-X Protein ; Carcinogenesis ; Carcinoma ; Carcinoma, Medullary ; Carcinoma, Papillary ; Cell Death ; Goiter ; Humans ; Membrane Proteins ; Paraffin ; Thyroid Gland* ; Thyroid Neoplasms*

3-Deazaadenosine (DZA), a potent inhibitor of S-adenosylhomocysteine hydrolase, was previously proposed to induce intrinsic apoptosis in human leukemic cells. In the present study, we analyzed the mechanism underlying the DZA-induced intrinsic apoptotic pathway. DZA activated typical caspase-dependent apoptosis in HL-60 cells, as demonstrated by an accumulation of hypo-diploidic cells, the processing of multiple procaspases and an inhibitory effect of z-VAD-Fmk on this cell death. During DZA-induced apoptosis, cytochrome c (cyt c) was released into the cytosol. This was neither prevented by z-VAD-Fmk and nor was it associated with the dissipation of mitochondrial membrane potential (DeltaPsim). Prior to the release of cyt c, BAX was translocated from the cytosol to mitochondria and underwent oligomerization. Finally, the overexpression of BCL-XL protected HL-60 cells from apoptosis by blocking both the cyt c release and BAX oligomerization. Collectively, these findings suggest that DZA may activate intrinsic apoptosis by stimulating BAX activation and thereby the release of cyt c.
Adenosylhomocysteinase ; Amino Acid Chloromethyl Ketones ; Apoptosis ; bcl-2-Associated X Protein ; bcl-X Protein ; Cell Death ; Cytochromes c ; Cytosol ; HL-60 Cells ; Humans ; Membrane Potential, Mitochondrial ; Mitochondria ; Tubercidin

Apoptosis is the major mechanism of cancer cell death by chemotherapy as well as radiation. Bax is a critical downstream mediator of apoptosis which belonged to the Bcl-2 family, and it initiates a mitochondrial permeability shift transition, leading to the activation of downstream apoptosis signaling pathways. Bax protein is activated by BH3-only proteins or p53, while prosurvival Bcl-2 family proteins suppress the function of Bax protein. Therefore, genetic defects in Bax may not only result in intrinsic biologic aggressiveness but also cause resistance to the cytotoxic effects of chemotherapy and radiotherapy. The role of low expression of Bax protein as a poor prognostic or predictive factor has been reported in several malignancies such as breast, colorectal, ovarian, esophageal, and head and neck cancer. Various novel therapeutic approaches targeting Bax protein are under investigation. In addition, several studies suggest that the evaluation of Bax protein with a pretreatment biopsy specimen may provide valuable information to the oncologist for the selection of appropriate therapeutic modality for the patients.
Apoptosis ; bcl-2-Associated X Protein* ; Biopsy ; Breast ; Cell Death ; Drug Therapy ; Head and Neck Neoplasms ; Humans ; Permeability ; Radiotherapy

PURPOSE: Apoptosis is active cell death which plays an important role in developing normal tissues. Various conditions such as genetic defects, drugs, ischemia or infections are known to induce apoptosis. We studied the effect of maternal infection on fetal brain development during pregnancy. METHODS: We treated 46 C3H pregnant mice with lipopolysaccharide (LPS) or phosphat-buffered saline and observed the changes in apoptosis and expression of bcl-2, bcl-xS, bax. The fetal brain tissues were removed 1-48 hours after LPS treatment. The number of apoptosis per 100 neurons and glial cells was counted in H&E stained tissue and was analyzed statistically. Immunohistochemical staining with primary antibodies of bcl-2, bcl-xS, bax was done and their expression was classified by the degree of staining. RESULTS: The number of apoptosis was increased significantly in both neurons and glial cells of LPS-treated group and its degree of staining was more remarkable in glial cells. Immunohisto chemistry for bcl-2, bcl-xS, bax oncoprotein revealed mildly decreased expression of bcl-2 and markedly increased expression of bax in both neurons and glial cells, but it was more remarkable in glial cells. Immunochemistry for bcl-xS revealed no expression in neurons and minimal expression of bcl-xS in glial cells in both study groups. CONCLUSOIN: We observed an increase in the number of apoptosis, mildly decreased expression of bcl-2 and markedly increased expression of bax in both neurons and glial cells of fetal brain after treating pregnant mice with LPS. Maternal infection during pregnancy may have profound effects on developing fetal brain.
Animals ; Antibodies ; Apoptosis* ; bcl-2-Associated X Protein* ; Brain* ; Cell Death ; Chemistry ; Immunochemistry ; Ischemia ; Mice* ; Neuroglia ; Neurons ; Pregnancy

OBJECTIVETo deeply explore the effects of microcystins (MC-LR) on Bax and Bcl-2 during the course of MC-LR promoting liver tumor.

METHODSapplied to set up the animal model, and the effect of MC-LR promoting liver tumor was evaluated by the Albertgamma-GT methods. And then, the immunohistochemical technique, RT-PCR and image analysis were used to study the expression of the Bcl-2 and Bax during the course of promoting tumor.

RESULTS(1) MC-LR might enhance the positive reaction rate of GGT. The positive reaction rate of GGT in DEN + pure toxin group was 100%, it was significantly higher than the DEN control group 22.22% (P < 0.05). (2) The intension and areas of the protein expression of Bcl-2 in DEN + pure toxin group were 0.0977 and 0.0315, and in DEN control group were 0.0460 and 0.0205, respectively. The expression level of Bcl-2 protein in DEN + pure toxin group were significantly higher than in DEN control group (P < 0.05). Simultaneously, the protein expression of Bax was significantly decreased by MC-LR (P < 0.05). The intension and areas of the expression of Bax in DEN + pure toxin group were 0.0283 and 0.0073, and in DEN control group were 0.0655 and 0.0244 respectively. (3) The mRNA expression of Bcl-2 was significantly increased by MC-LR. The intension of Bcl-2 mRNA expression in DEN + pure toxin group was 2.244, being significantly higher than in the other groups (P < 0.05). However, the mRNA expression of Bax showed no significant difference between DEN + pure toxin and the other groups.

CONCLUSIONThe expression change of Bcl-2 and Bax should possibly play an important role in the course of MC-LR promoting liver tumor.

Animals ; Apoptosis ; Carcinogens ; toxicity ; Hepatocytes ; metabolism ; Liver Neoplasms ; chemically induced ; metabolism ; Male ; Microcystins ; toxicity ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; bcl-2-Associated X Protein ; biosynthesis ; bcl-Associated Death Protein ; biosynthesis

BACKGROUND: The FHIT (fragile histidine triad) gene is a frequent target of deletions associated with abnormal RNA and protein expression in lung cancer. Previous studies have shown FHIT gene transfer into lung cancer cell line lacking FHIT protein expression resulted in inhibition of tumor cell growth attributable to the induction of apoptosis and reversion of tumorigenecity. However, the mechanism of the tumor suppressor activity of the FHIT gene and the cellular pathways associated with its function are not completely understood. METHODS: To gain insight into the biological function of FHIT, we compared the NCI-H358 cell line with its stable FHIT transfectants after treatment with cisplatin or paclitaxel. We investigated the effects of FHIT gene expression on cell proliferation, apoptosis, and activation of caspase system and Bcl-2 family. The induction of apoptosis was evaluated by using DAPI staining and flow cytometry. Activation of caspases and Bcl-2 members was evaluated by Western blot analysis. RESULTS: A significantly increased cell death was observed in FHIT transfectants after cisplatin or paclitaxel treatment and this was attributable to the induction of apoptosis. Remarkable changes in caspases and Bcl-2 family were observed in the transfected cells as compared with the control cells after treatment with paclitaxel. Activation of caspase-3 and caspase-7 was markedly increased in cells expressing FHIT. Expression level of Bcl-2 and Bcl-xL protein was significantly decreased and that of Bax and Bad protein was significantly increased in the transfected cells. CONCLUSION: FHIT gene delivery into lung cancer cells results in enhanced apoptosis induced by treatment with cisplatin or paclitaxel. The data suggest that apoptosis in FHIT-expressing cells could be related to activation of caspase pathway and Bcl-2 family.
Apoptosis* ; bcl-Associated Death Protein ; bcl-X Protein ; Blotting, Western ; Caspase 3 ; Caspase 7 ; Caspases ; Cell Death ; Cell Line* ; Cell Proliferation ; Cisplatin ; Flow Cytometry ; Gene Expression ; Histidine ; Humans ; Lung Neoplasms* ; Lung* ; Paclitaxel ; RNA

OBJECTIVETo study the effects of sodium butyrate (NaBu) on cell cycle checkpoint and the apoptosis sensitivity in U937 cells.

METHODSTwo mutant U937 cell lines, U937-ASPI3K (ATM negative) and U937-pZeosv2(+) (ATM wild-type), were used as the cell model system. Immunoprecipitation and kinase assay were used to examine the p38 MAPK and ERK1 kinase activities. Western blot was used to analyze the phosphorylation of Bad protein.

RESULTSU937-pZeosv2(+) pretreated with NaBu exhibited enhanced apoptotic response in a NaBu dose dependent fashion upon (137)Cs irradiation, which could be abolished by olomoucine (OLM), a p38 MAPK specific inhibitor. On the other hand, Cyclin dependent kinase 2 (CDK2) specific inhibitor CDK2-I and p34cdc2/cyclinB inhibitor alsterpaullone (ALP) failed to block the effects of NaBu. Similar results were also observed in U937-ASPI3K. The effect of irradiation on p38 MAPK and ERK1 was strikingly potentiated by NaBu. Furthermore, inactivation of irradiated Bad protein via phosphorylation on serine 136 was also enhanced.

CONCLUSIONNaBu is able to enhance the apoptotic response in U937 cells, which is mediated by p38 MAPK activation but not ATM status.

Apoptosis ; Butyrates ; pharmacology ; Carrier Proteins ; metabolism ; Humans ; MAP Kinase Signaling System ; Mitogen-Activated Protein Kinase 3 ; Mitogen-Activated Protein Kinases ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; U937 Cells ; bcl-Associated Death Protein ; p38 Mitogen-Activated Protein Kinases