BACKGROUNDUncontrolled cell division is one of the hallmarks of tumor growth. Researches have been focused on numerous molecules involved in this process. Cyclins are critical regulatory proteins of cell cycle progression and/or transcription. The present study aimed to investigate the anti-proliferative effect of cyclin L2, and to define its growth regulatory mechanisms using human lung adenocarcinoma cell line A549.

METHODSHuman cyclin L2 was transfected into human lung adenocarcinoma cells (A549 cell), and was expressed in a mammalian expression vector pcDNA3.1. The effects and mechanisms of the cyclin L2 in cell growth, cell cycle analysis and apoptosis were studied by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), flow cytometry or Western blot, respectively.

RESULTSOverexpression of cyclin L2 inhibited the growth of A549 cells. Cell cycle analysis in cells transfected with pCCNL2 revealed an increment in proportion in G0/G1 phase ((68.07 +/- 4.2)%) in contrast to (60.39 +/- 2.82)% of the cells transfected with mock vector. Apoptosis occurred in (7.25 +/- 0.98)% cells transfected with pCCNL2, as compared with (1.25 +/- 0.21)% of the mock vector control group. Cyclin L2-induced-G0/G1 arrest and apoptosis involved upregulation of caspase-3 and downregulation of Bcl-2 and survivin.

CONCLUSIONThe results indicate that overexpression of cyclin L2 protein may promote efficient growth inhibition of human lung adenocarcinoma cells by inducing G0/G1 cell cycle arrest and apoptosis.

Apoptosis ; Caspase 3 ; biosynthesis ; Cell Cycle ; Cell Line, Tumor ; Cyclins ; genetics ; physiology ; Humans ; Lung Neoplasms ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; Transcription Factors ; genetics ; physiology ; Transfection

OBJECTIVETo achieve expression of human brain-derived neurotrophic factor (hBDNF) mediated by recombinant adeno-associated virus (rAAV) and explore the mechanism of its neuroprotective effects in rat neurons against beta-amyloid-induced Alzheimer's disease.

METHODSUsing molecular cloning technique, rAAV vector containing hBDNF gene (AAV-hBDNF) was constructed to transfect SD rat hippocampal neurons exposed to beta-amyloid treatment. The changes in cell apoptosis were observed by MTT assay and flow cytometry, and the expression of hBDNF and Bcl-2 protein were determined by immunocytochemical staining. Laser scanning confocal microscopy (LSCM) was used to observe the changes of [Ca(2+)](i).

RESULTSThe cultured rat hippocampal neurons were effectively transfected with AAV-hBDNF and expression of BDNF protein was obviously increased. hBNDF expression showed significant protective effects against beta-amyloid-induced neuronal damage, and the expression of Bcl-2 protein was increased significantly and the balance of [Ca(2+)](i) was maintained in BDNF-treated cells with beta-amyloid exposure.

CONCLUSIONhBDNF expression can effectively protect cultured rat hippocampal cells from beta-amyloid-induced apoptosis through inhibiting the intracellular calcium overload and increasing the expression of Bcl-2 protein.

Alzheimer Disease ; genetics ; metabolism ; pathology ; Amyloid beta-Peptides ; toxicity ; Animals ; Animals, Newborn ; Brain-Derived Neurotrophic Factor ; biosynthesis ; genetics ; physiology ; Cell Line ; Cell Survival ; drug effects ; genetics ; physiology ; Cells, Cultured ; Dependovirus ; genetics ; Genetic Vectors ; Hippocampus ; cytology ; metabolism ; Humans ; Immunohistochemistry ; Microscopy, Electron, Scanning ; Neurons ; drug effects ; metabolism ; ultrastructure ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Transfection

To determine the possible roles of survivin in the pathogenesis of myelodysplastic syndrome (MDS) and to explore the relationship between apoptosis and angiogenesis in MDS, the expressions of survivin, Bcl-2 and VEGF were detected in the BM cells of de novo patients with MDS, patients with AML and individuals of control by immunochemical staining and their relationship was analyzed. The results showed that the expression rate and integral of all the three proteins in the low-risk group of MDS, high-risk group of MDS and de novo acute myeloid leukemia patients gradually increased, in addition to expression of Bcl-2 in low-risk group of MDS and control group. The significant differences were observed in every two groups and there were positive relations between the every two proteins. It is concluded that survivin, Bcl-2 and VEGF are all involved in the pathogenesis of MDS, and related with the progression of this disease, the deregulated apoptosis and angiogenesis may be involved in the pathogenesis of MDS through interaction among three proteins mentioned above.
Adult ; Apoptosis ; physiology ; Bone Marrow Cells ; metabolism ; pathology ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; Male ; Microtubule-Associated Proteins ; biosynthesis ; genetics ; Myelodysplastic Syndromes ; metabolism ; pathology ; Neoplasm Proteins ; biosynthesis ; genetics ; Neovascularization, Pathologic ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Vascular Endothelial Growth Factor A ; biosynthesis ; genetics

OBJECTIVETo explore the effects of hyperbaric oxygen (HBO) treatment on the neuronal apoptosis at an earlier stage and the expressions of Cytochrome C (Cyt C), Bcl-2 (B-cell lymphoma-2 family) and Bax (Bcl-2 associated X protein) in rat brain tissues after traumatic brain injury (TBI).

METHODSForty adult rats were divided into two groups, i.e., Group A (the rats with untreated TBI) and Group B (rats with HBO treatment after TBI). Sections of brain tissues of these two groups were then detected at 3, 6, 12, 24, 72 hours after TBI by immunohistochemistry and electronmicroscope, respectively.

RESULTSHBO treatment could up-regulate the expression of Bcl-2 within 72 hours, reduce the release of Cyt C from mitochondria, attenuate the formation of dimeric Bax and alleviate the mitochondrial edema within 24 hours after TBI.

CONCLUSIONSHBO treatment can alleviate neuronal apoptosis after TBI by reducing the release of Cyt C and the dimers of Bax and up-regulating the expression of Bcl-2.

Analysis of Variance ; Animals ; Apoptosis ; physiology ; Brain Injuries ; pathology ; therapy ; Cytochromes c ; biosynthesis ; Disease Models, Animal ; Hyperbaric Oxygenation ; Immunohistochemistry ; Male ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; biosynthesis

OBJECTIVETo observe the effect of KLF6 on prostate cancer cell line PC-3 by transgenic method.

METHODSWe obtained KLF6 cDNA by RT-PCR method from the liver cell, transfected plasmid pEGFP-C, recombinated with KLF6 into PC-3 cells, and used them as a transfection group and a control group. MTT, flow cytometer and immunocytochemical methods were used to observe the effect of anti-oncogene wild type KLF6 on prostate cancer cell line PC-3 by transgenic method for 48 hours.

RESULTSAfter transfected into PC-3 cells, KLF6 enhanced growth suppression, (30.0 +/- 5.4)% in the transfection group and 0% in the control, P < 0.01, apoptosis, (24.3 +/- 2.3)% in the transfection group and (5.2 +/- 0.7)% in the control, P < 0.01, the down-regulation of the expression of cyclin D1, (25.3 +/- 3.7)% in the transfection group and (38.5 +/- 4.6)% in the control, P < 0.05 and Bcl-2, (18.7 +/- 3.2)% in the transfection group, and (41.8 +/- 5.9)% in the control, P < 0.01 in PC-3 cells. It also decreased the ratio of the cell phase G2/M, increased the ratio of G0/G1 from (58.6 +/- 7.3)% in the control to (80.0 +/- 9.8)% in the transfection group, P < 0.05.

CONCLUSIONPC-3 cells transfected with wild type KLF6 can enhance its growth suppression and apoptosis. It shows great potential for the gene therapy of androgen-independent carcinoma of the prostate.

Apoptosis ; physiology ; Cell Cycle ; physiology ; Cell Line, Tumor ; Cyclin D1 ; biosynthesis ; Down-Regulation ; Flow Cytometry ; Humans ; Immunohistochemistry ; Kruppel-Like Factor 6 ; Kruppel-Like Transcription Factors ; genetics ; physiology ; Male ; Prostatic Neoplasms ; metabolism ; pathology ; Proto-Oncogene Proteins ; genetics ; physiology ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection

To evaluate the expressions of proliferative antigen Ki-67 and apoptosis-antagonizing protein Bcl-2 as well as their clinical significance, immunohistochemistry staining with SAP was used to detect Ki-67 antigen and Bcl-2 protein in 18 cases of children with acute lymphoblastic leukemia (ALL) and 43 cases of adults with ALL. The results showed that the levels of Ki-67 and Bcl-2 expression in children with ALL were lower than that in adults, but only Bcl-2 expression had significant difference. Both in children and in adults, the levels of Ki-67 expression in T-ALL and My(+) ALL were higher than that in B-ALL and null-ALL. The highest complete remission rate (CR) was seen in the group with lower expression of both indexes (Ki-67 and Bcl-2). The lowest CR rate was seen in the group with higher expression of both indexes. It is concluded that the levels of Ki-67 and Bcl-2 expression in children and adults with ALL were closely related with the subtype of ALL and chemotherapeutic effects.
Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Apoptosis ; physiology ; Child ; Child, Preschool ; Female ; Humans ; Ki-67 Antigen ; biosynthesis ; Male ; Middle Aged ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis

OBJECTIVE: To investigate the effect of yizhi jiannao granule concentration fluid (YCF) on the behavior, the apoptosis rate of hippocampus neuron and the expression of apoptosis gene Bcl-2, Bax in senescence accelerated mice Senile-Prone/8 (SAMP/8), and to discuss some mechanism of traditional chinese medicine YCF in improving the capability of learning and memory. METHODS: Forty 6-month old SAMP/8 mice were randomly divided into the old group, huperzine A (Hup-A) group and YCF group. Ten 4-month old SAMP/8 mice were served as a young control group. Four groups were given different drugs for 8 weeks, their behavior changes were observed, and the hippocampus were taken out to examine the apotosis rate by flow cytomeutry (FCM) and the expression of Bcl-2, Bax mRNA by RT-PCR. RESULTS: In the YCF group, the escape latency was significantly shortened, the time of swim in the platform quadrant significantly increased, the apoptosis rate of hippocampus neural decreased; the level of Bcl-2 mRNA and the rate of Bcl-2/Bax increased, and the level of Bax mRNA decreased. CONCLUSION Yizhi jiannao granule can decrease the neuron apoptosis rate and the Bax level, increase the Bcl-2 level, and modulate the rate of Bcl-2/Bax in SAMP/8 brain, which is probably part of the mechanisms of inhibiting the apoptosis and improving learning and memory.
Aging ; drug effects ; pathology ; physiology ; Animals ; Apoptosis ; drug effects ; Behavior, Animal ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Hippocampus ; pathology ; Learning ; drug effects ; Memory ; drug effects ; Mice ; Neurons ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; bcl-2-Associated X Protein ; biosynthesis ; genetics

In order to study the potential effects of exogenous WT1 gene isoform on apoptosis in leukemia cell line NB4 and its possible molecular mechanisms, the eukaryotic expression recombinant vector (pCB6(+)/WTA) containing full-length human WT1 isoform (WTA: -17aa/-KTS) cDNA and the vacant vector-alone were introduced into the leukemia cell line NB4 respectively by electroporation. The WTA mRNA and protein in cells were detected by RT-PCR and Western blot. Binding of Annexin V were tested by flow cytometry and agarose gel electrophoresis to verify whether exogenous WTA could induce apoptosis of NB4 cells. Expressions of p21, p53, bcl-2, bcl-XL and c-myc genes were determined by semi-quantitative RT-PCR after introducing recombinant vectors into the NB4 cells. The results showed that in exposure to As(2)O(3) at 0.8 micromol/L for 48 hours, the NB4/WTA cells exhibited the morphological hallmarks of apoptosis, the marked DNA ladder shown by gel electrophoresis, and the enhanced apoptosis rate marked by Annexin V. RT-PCR showed an increase in p21 and c-myc genes expression, a decrease in bcl-2 and a relative constant expression of p53, bcl-XL in NB4/WTA cells. It is concluded that the introduction and expression of exogenous WTA gene can lead to apoptosis of NB4/WTA cells by down-regulating the Bcl-2 gene expression and up-regulating the p21 and c-myc genes expression.
Apoptosis ; genetics ; physiology ; Blotting, Western ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Leukemia ; genetics ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Proto-Oncogene Proteins c-myc ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; Tumor Suppressor Protein p53 ; genetics ; WT1 Proteins ; genetics ; metabolism ; physiology ; bcl-X Protein ; genetics

Adult ; Female ; Hepatitis C, Chronic ; virology ; Humans ; Liver Cirrhosis ; virology ; Male ; Middle Aged ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Viral Core Proteins ; physiology

The purpose of the present study was to explore the seizure-induced changes in Bad (Bcl-2-associated death protein), 14-3-3, phosphoBad, Bcl-2 and Bcl-XL expression in the rat model of focal limbic seizure. Unilateral intra-amygdaloid injection of kainic acid (KA) was made to induce seizure. Electroencephalogram (EEG) and regional cerebral flow (r-CBF) were monitored continuously. Diazepam (30 mg/kg) was administered to terminate the seizure. The apoptotic and surviving neurons in the hippocampus were observed by terminal deoxynucleotidyl transferrase-mediated dUTP nick end labeling (TUNEL) and cresyl violet staining, the expression of Bad, 14-3-3, phosphoBad, Bcl-2 and Bcl-XL were detected with immunofluorescence, Western blot and immunoprecipitation. The results showed that TUNEL-positive neurons appeared at 8 h and reached maximum at 24 h following seizure cessation within the ipsilateral CA3 subfield of the hippocampus. Seizure induced the dephosphorylation of Bad and the dissociation of Bad from its chaperone protein 14-3-3 and subsequent dimerization of Bad with Bcl-XL. The expression of phosphoBad decreased and Bcl-2 increased. There was little change in r-CBF after the seizure. These results suggest that seizure leads to a dephosphorylation of Bad and an upregulation of Bcl-2. Dephosphorylation of Bad may be injurious while the upregulation of Bcl-2 may be protective to the brain damage induced by seizures, but not related with r-CBF.
Amygdala ; physiology ; Animals ; Epilepsies, Partial ; chemically induced ; metabolism ; Hippocampus ; metabolism ; Kainic Acid ; Male ; Microinjections ; Phosphorylation ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Rats ; Up-Regulation ; bcl-Associated Death Protein ; metabolism