OBJECTIVETo investigate the effect of X-rays on expression of caspase-3 and p53 protein in EL-4 cells and its implications in induction of apoptosis and polyploid cells.

METHODSMouse lymphoma cell line (EL-4 cells) was used. Fluorescent staining and flow cytometry analysis were employed for measurement of protein expression, apoptosis, cell cycle, and polyploid cells.

RESULTSThe expression of caspase-3 protein increased significantly at 8 h and 12 h, compared with that of sham-irradiated control (P<0.05, respectively) and the expression of p53 protein increased significantly at 2, 4, 8, 12, and 24 h, compared with that of sham-irradiated control (P<0.05-P<0.01) in EL-4 cells after 4.0 Gy X-irradiation. Apoptosis of EL-4 cells was increased significantly at 2, 4, 8, 12, 24, 48, and 72 h after 4.0 Gy exposure, compared with that of sham-irradiated control (P<0.05-P<0.001). G2 phase cells were increased significantly at 4, 8, 12, 24, 48, and 72 h (P<0.05-P<0.001). However, no marked change in the number of 8 C polyploid cells was found from 2 to 48 h after 4.0 Gy exposure.

CONCLUSIONThe expressions of caspase-3 and p53 protein in EL-4 cells are induced by X-rays, which might play an important role in the induction of apoptosis, and the molecular pathway for polyploid formation might be p53-independent.

Animals ; Caspase 3 ; metabolism ; radiation effects ; Caspases ; metabolism ; radiation effects ; Cell Line, Tumor ; Mice ; Tumor Suppressor Protein p53 ; metabolism ; radiation effects ; X-Rays

The aim of this study was to investigate the effects of the traditional Chinese medicine psoralen (PSO) plus long wave ultraviolet A (PUVA) on apoptosis in HL-60 leukemia cells and its mechanism. The effect of PUVA on HL-60 cell growth was assayed by MTT method and the changes of ultrastructure of cells were observed by electron microscopy. The apoptosis ratios, changes of mitochondrial membrane potential, expression of Fas and FasL protein and Fas and FasL mRNA were detected by FCM and fluorescent quantitation RT-PCR respectively. The expression of Caspase 8 and Caspase 3 protein were detected by immunocytochemistry (ICC). The results showed that the growth of HL-60 cells were inhibited by PUVA in time-and concentration-dependent manner through inducing cell apoptosis. When the irradiation time of long wave ultraviolet A lasted 15 minutes and the concentration of PSO was 80 microg/ml, the inhibition of HL-60 cell proliferation and apoptosis ratios reached the peak. There were obvious apoptotic ultrastructure changes and decrease of mitochondrial membrane potential in HL-60 cells after treatment with PUVA. The expression of Fas mRAN increased and expression of FasL mRNA decreased after treating with PUVA for 4 hours, and the same results of Fas, FasL expression on protein level were obtained also after treating with PUVA for 24 hours. The expression of caspase 8 and caspase 3 protein enhanced and reached the peak after treating with PUVA for 8 hours. It is concluded that the PUVA can inhibit the growth of HL-60 cells and induce apoptosis of these cells. The possible mechanism is supposed to be up-regulating Fas, down-regulating FasL levels and then activating the levels of caspase 8 and caspase 3. The decreasing of mitochondrial membrane potential may be involved in this process probably.
Apoptosis ; drug effects ; radiation effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Fas Ligand Protein ; metabolism ; Ficusin ; pharmacology ; HL-60 Cells ; Humans ; Ultraviolet Rays ; fas Receptor ; metabolism

OBJECTIVETo investigate the role of Caspase-3 in retinal damage caused by light exposure in rats.

METHODSLight injury to retina was induced by persistent exposure to illumination (intensity: 30 000 +/- 50 lux) of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1, 3, 7, and 15 days after the light exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis.

RESULTSThe examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, especially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pigment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day (82.7%) and 15th day (80.4%), however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9.8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day.

CONCLUSIONApoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.

Animals ; Apoptosis ; radiation effects ; Caspase 3 ; genetics ; metabolism ; radiation effects ; Dose-Response Relationship, Radiation ; Enzyme Activation ; Gene Expression Regulation, Enzymologic ; radiation effects ; Light ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Retina ; enzymology ; pathology ; radiation effects ; ultrastructure

OBJECTIVETo study the regulatory effects of psoralen (PSO) plus ultraviolet A (UVA), which is PUVA, on cell apoptosis of human leukemia cell line NB4 and signal pathway of cell apoptosis.

METHODSHuman leukemia cell line NB4 was cultured in vitro. The NB4 cells were treated with PSO extracted from Chinese medicine psoralea fruits at different concentrations (0, 5, 10, 20 and 40 microL) plus UVA of wave length 360 nm at different irradiation time points (0 and 5 min). The apoptosis ratio was detected by flow cytometry (FCM). The ultrastructure changes were observed using transmission electron microscope (TEM). The expressions of Caspase-8 and Caspase-8 protein were detected by immunocytochemical method (ICC).

RESULTSAfter treatment of PSO at different concentrations with a 0 and 5-min exposure of UVA, the apoptosis rate of NB4 cells increased dose-and time-dependently, and was up to peak after treatment of PSO at 40 microg/mL with 5-min exposure of UVA. An interaction was shown between the two factors (P <0. 01). There were obvious morphological apoptosis of NB4 cells under TEM after treated with PUVA. The expressions of Caspase-3 and Caspase-8 protein were up-regulated by PSO, UVA, and PUVA, but the effects of PUVA on Caspase-3 protein were stronger than PSO and UVA at 12 h time-dependently (P <0.01).An interaction was shown between the concentration of PSO and time of UVA (P <0.01).

CONCLUSIONSThe optimal combination of PUVA was PSO in 40 microg/mL and 5-min exposure of UVA. PUVA could induce the apoptosis of NB4 cells and in vitro activate Caspase-3 and Caspase-8 genes.

Apoptosis ; drug effects ; radiation effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Ficusin ; pharmacology ; therapeutic use ; Humans ; Photochemotherapy ; methods ; Ultraviolet Rays

BACKGROUND: Lung cancer is one of the highest morbidity and mortality in the world and it is very important to find an effective anti-tumor method. Microwave hyperthermia, a new treatment technology, has been getting more and more attention. This study was designed to investigate the effects of microwave hyperthermia combined with gemcitabine on the proliferation and apoptosis of human lung squamous cell carcinoma (NCI-H1703 and NCI-H2170) in vitro. METHODS: The proliferation of cells treated with microwave hyperthermia, the effect of gemcitabine on cell proliferation and the proliferation of cells treated with different methods of microwave hyperthermia and gemcitabine were detected by CCK-8 assay. Colony formation assay was used to measure the colony formation of human lung squamous cell carcinoma cells. Flow cytometry assay was used to detect the total apoptosis rates of the treated cells. Caspase-3, Caspase-8 activity assay was used to detect the activity of Caspase-3, Caspase-8 enzyme in each group of cells. CCK-8 assay was used to detect the effect of control group, AC-DEVD (Caspase-3 inhibitor) group, thermalization combined group, and thermal AC-DEVD combined group on cell proliferation. The levels of p53, Caspase-3, Cleaved-Caspase-3, PARP, Bax and BCL-2 protein expression were detected using Western blot assay. RESULTS: Our results demonstrated that microwave hyperthermia inhibited the proliferation of lung squamous cell carcinoma. The IC₅₀ values of gemcitabine for the two cells were 8.89 μmol/L and 44.18 μmol/L, respectively. The first chemotherapy after microwave hyperthermia has synergistic effect on the two lung squamous cell carcinoma cells and can significantly inhibit the cell clone formation (P<0.001), promote cell apoptosis (P<0.001) and increase Caspase-3 enzyme activity (P<0.001). However, it has no effect on Caspase-8 enzyme activity (P>0.05). Furthermore, Western blot analysis showed that microwave hyperthermia combined with gemcitabine could up-regulate the p53, Caspase-3, Cleaved-Caspase-3, Cleaved-PARP and Bax protein expression. CONCLUSIONS Microwave hyperthermia combined with gemcitabine remarkably inhibit the proliferation and induce apoptosis of human lung squamous cell carcinoma in vitro. This effect may be associated with the activation of p53, cleavage of PARP protein, and induced the Caspase-3 dependent apoptosis.
Apoptosis ; drug effects ; radiation effects ; Carcinoma, Squamous Cell ; pathology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; radiation effects ; Combined Modality Therapy ; Deoxycytidine ; analogs & derivatives ; pharmacology ; Humans ; Hyperthermia, Induced ; Lung Neoplasms ; pathology ; Microwaves

PURPOSE: The purpose of this study is to understand the mechanism of apoptosis occurring on a cultured human lens epithelial cell line after exposure to ultraviolet (UV) light. We intended to confirm the presence of cellular toxicity and apoptosis and to reveal the roles of p53, caspase 3 and NOXA in these processes. METHODS: Cells were irradiated with an ultraviolet lamp. Cellular toxicity was measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Hoechst staining and fluorescent anti-caspase 3 antibodies were used for apoptosis investigation. The quantities of p53, caspase 3, and NOXA were measured by Western blotting for to investigate the apoptosis pathway. RESULTS: Cellular toxicity on the human lens epithelium markedly increased with time after UV exposure. On Hoechst staining, we found that apoptosis also remarkably increased after exposure to ultraviolet light, compared with a control group. In the immunochemical study using anti-caspase 3 antibodies, active caspase 3 significantly increased after exposure to ultraviolet light. On Western blotting, p53 decreased, while caspase 3 and NOXA increased. CONCLUSIONS: Exposure of cultured human lens epithelial cell lines to ultraviolet light induces apoptosis, which promotes the expression of NOXA and caspase 3 increases without increasing p53. This may suggest that UV induced apoptosis is caused by a p53-independent pathway in human lens epithelial cells.
Apoptosis/*physiology ; Caspase 3/metabolism ; Cell Line ; Cell Survival/radiation effects ; Epithelial Cells/radiation effects ; Humans ; Lens, Crystalline/cytology/*physiology/*radiation effects ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Tumor Suppressor Protein p53/metabolism ; *Ultraviolet Rays

This in vitro study evaluated the detrimental effect of acute gamma (gamma)-irradiation on rat immature hippocampal neurons. Rat immature hippocampal neurons (0.5 day in vitro) were irradiated with 0~4 Gy gamma-rays. Cytotoxicity was analyzed using a lactate dehydrogenase release assay at 24 h after gamma-irradiation. Radiation-induced cytotoxicity in immature hippocampal neurons increased in a dose-dependent manner. Pre-treatments of pro-apoptotic caspase inhibitors and anti-oxidative substances significantly blocked gamma-irradiation-induced cytotoxicity in immature hippocampal neurons. The results suggest that the caspase-dependent cytotoxicity of gamma-rays in immature hippocampal cultured neurons may be caused by oxidative stress.
Amifostine/pharmacology ; Animals ; Antioxidants/pharmacology ; Caspase 3/metabolism/radiation effects ; Catechin/analogs & derivatives/pharmacology ; Cell Survival/radiation effects ; Cells, Cultured/cytology/enzymology/*radiation effects ; Dose-Response Relationship, Radiation ; Female ; *Gamma Rays ; Hippocampus/cytology/enzymology/*radiation effects ; L-Lactate Dehydrogenase/radiation effects ; Neurons/cytology/enzymology/*radiation effects ; Poly(ADP-ribose) Polymerases/drug effects ; Pregnancy ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of celecoxib combined with radiotherapy on apoptosis of CNE-2Z cell lines and the potential mechanisms.

METHODSFour groups were used, a control, celecoxib (25 micromol/L celecoxib), irradiation (8 Gy X ray) and celecoxib plus irradiation. The radiosensitising effect was detected by clone formation experiment. Flow cytometry was used to detect the apoptosis rate of cells. The expressions of Bcl-2 and Bax were assessed by immunocytochemistry. Western blot was used to examine the expression of Caspase-3.

RESULTSCelecoxib enhanced the radiosensitivity of CNE-2Z cells. In experimental group, the mean surviving fraction and the mean lethal dose of CNE-2Z cells were 0.50 and 2.36 respectively. Compared with the irradiated group, there was significant differences between the two groups (P < 0.01). Celecoxib combined with radiotherapy up-regulation the expression of Bax. The score of the expression of Bax in the control group and the experimental group were 1.221 +/- 0.116 and 2.758 +/- 0.256 respectively. Celecoxib combined with radiotherapy could inhibit the expression of the protein of Bcl-2. The score of the expression of Bcl-2 in the control group and the experimental group were 2.559 +/- 0.144 and 1.253 +/- 0.114 respectively, with significant differences (P < 0.01). Celecoxib combined with radiotherapy could increase the apoptosis rate of tumor cells with significant differences (F = 7.63, P < 0.01). Western blot showed that the expression of Caspase-3 was strengthened.

CONCLUSIONCelecoxib combined with radiotherapy could induce apoptosis and enhance the radiosensitivity of human nasopharyngeal carcinoma CNE-2Z cell lines.

Apoptosis ; drug effects ; radiation effects ; Carcinoma ; Caspase 3 ; metabolism ; Celecoxib ; Cell Line, Tumor ; drug effects ; radiation effects ; Humans ; Nasopharyngeal Neoplasms ; pathology ; therapy ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Pyrazoles ; pharmacology ; Radiotherapy ; Sulfonamides ; pharmacology ; bcl-2-Associated X Protein ; metabolism

We investigated the effect of low dose radiation on diabetes induced suppression of neurogenesis in the hippocampal dentate gyrus of rat. After 0.01 Gy, 0.1 Gy, 1 Gy and 10 Gy radiation was delivered, the dentate gyrus of hippocampus of streptozotocin (STZ)-induced diabetic rats were evaluated using immunohistochemistry for 5-bromo-2-deoxyuridine (BrdU), caspase-3, and terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) staining. The number of BrdU positive cells in the non-diabetic rats, diabetic rats without radiation, diabetic rats with 0.01 Gy radiation, diabetic rats with 0.1 Gy radiation, diabetic rats with 1 Gy radiation and diabetic rats with 10 Gy radiation were 55.4+/-8.5/mm2, 33.3+/-6.4/mm2, 67.7+/-10.5/mm2, 66.6+/-10.0/mm2, 23.5+/-6.3/mm2 and 14.3+/-7.2/mm2, respectively. The number of caspase-3 positive cells was 132.6+/-37.4/mm2, 378.6+/-99.1/mm2, 15.0+/-2.8/mm2, 57.1+/-16.9/mm2, 191.8+/-44.8/mm2 and 450.4+/-58.3/mm2, respectively. The number of TUNEL-positive cells was 24.5+/-2.0/mm2, 21.7+/-4.0/mm2, 20.4+/-2.0/mm2, 18.96+/-2.1/mm2, 58.3+/-7.9/mm2, and 106.0+/-9.8/mm2, respectively. These results suggest low doses of radiation paradoxically improved diabetes induced neuronal cell suppression in the hippocampal dentate gyrus of rat.
Rats, Sprague-Dawley ; Rats ; Radiotherapy/methods ; Neurons/*metabolism ; Male ; In Situ Nick-End Labeling ; Hippocampus/*cytology/metabolism/radiation effects ; Diabetes Mellitus, Experimental/radiotherapy ; Dentate Gyrus/drug effects/*radiation effects ; Cell Proliferation ; Caspase 3/metabolism ; Bromodeoxyuridine/pharmacology ; Apoptosis ; Animals

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot, immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.
Animals ; Antigens, CD147/*metabolism ; Brain/blood supply/metabolism/pathology/*radiation effects ; Brain Injuries/metabolism/pathology ; Caspase 3/metabolism ; Gamma Rays/*adverse effects ; Immunohistochemistry ; Male ; Microscopy, Electron, Transmission ; Parietal Lobe/metabolism/pathology/radiation effects ; Radiation Injuries, Experimental/metabolism ; Radiosurgery/adverse effects ; Rats ; Rats, Wistar ; Time Factors ; Vascular Endothelial Growth Factor A/*metabolism