The Expression of Apoptosis-Related Genes Bcl-2 and Bax Protein and Apoptosis Positivity in Cervical Carcinoma during Irradiation

To evaluate the apoptosis positivity, the expression of Bcl-2, bax proteinsin 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By usingimmuno-histochemical and TDT-dUTP nick end labelling techniques, 30 cases of squamous cell cervicalcarcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%and 100% respectively, with the difference being significant (P 【 0.05); The positive rates of Bcl-2protein before and after irradiation were 73.3% and 46.7% respectively, with the difference beingsignificant (P 【 0.05); The positive rates of bax protein before and after irradiation were 86% and100% respectively, with the difference being significant (P 【 0.05). Conclusion: bax and Bcl-2protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosisinduced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2protein.

Effect of Helicobacterpyloriinfection on Bax protein expression in patients with gastric precancerous lesions

AIM： To investigate the effect of Helicobacter pylori （H pylon） infection on Bax protein expression, and explore the role of Hpyloriin gastric carcinogenesis. METHODS： Hpyloriwas assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions. RESULTS： Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in Hpylori-positive gastric precancerous lesions （72.3%） was significantly higher than that in H pylori-negative gastric precancerous lesions （48.0%, x^2= 4.191, P〈0.05）. Hpyloriinfection was well correlated with the expression of Bax protein in gastric precancerous lesions （r= 0.978, P〈0.01）. After eradication of H pylori, the positivity of Bax protein expression significantly decreased in Hpylori-positive gastric precancerous lesions （x^2 = 5.506, P〈0.05）. In the persisting H pylori-infected patients, the positivity of Bax protein expression was not changed. CONCLUSION： H pyloriinfection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of Hpyloriinfection-induced gastric epithelial cell apoptosis. Hpylorimight act as a tumor promoter in the genesis of gastric carcinoma and eradication of Hpylori could inhibit gastric carcinogenesis.

Differential expression of Bcl-2 and Bax during gastric ischemia-reperfusion of rats

AIM: To investigate expression of Bcl-2 and Bax in gastric ischemia-reperfusion (GI-R) and involvement of extracellular signal-regulated kinase (ERK) 1/2 activation. METHODS: The GI-R model was established by ligature of the celiac artery for 30 min and reperfusion in SpragueDawley rats. Rats were assigned to groups in accordance with their evaluation period: control, 0, 0.5, 1, 3, 6, 24, 48, and 72 h. Expression and distribution of Bcl-2 and Bax proteins were analyzed by immunohistochemistry and western blotting in gastric tissue samples after sacrifice. RESULTS: Compared with controls, the percentage of positive cells and protein levels of Bcl-2 decreased inthe early phases of reperfusion, reached its minimum at 1 h (P < 0.05); it then increased, reaching its peak at 24 h of reperfusion (P < 0.05). The pattern of Bax expression was opposite to that of Bcl-2. Bax expression increased after reperfusion, with its peak at 1 h of reperfusion (P < 0.05), and then it decreased gradually to a minimum at 24 h after reperfusion (P < 0.05). On the other hand, inhibition of activation of ERK1/2 induced by PD98059, a specific upstream MEK inhibitor, had significant effects on Bcl-2 and Bax in GI-R. Compared with GI-R treatment only at 3 h of reperfusion, PD98059 reduced the number of Bcl-2 positive cells (0.58% of R3h group, P < 0.05) and Bcl-2 protein level (74% of R3h group, P < 0.05) but increased the number of Bax-positive cells (1.33-fold vs R3h group, P < 0.05) and Bax protein level (1.35-fold of R3h group, P < 0.05). CONCLUSION: These results indicated that the Bcl-2 and Bax played a pivotal role in the gastric mucosal I-R injury and repair by activation of ERK1/2.

Connexin 26 correlates with Bcl-xL and Bax proteins expression in colorectal cancer

AIM: To evaluate of Cx26 in correlation with Bcl-xL and Bax proteins in colorectal cancer. METHODS: Immunohistochemical staining using specific antibodies was performed to evaluate the protein expression of Cx26, Bax and Bcl-xL in 152 colorectal cancer samples and the correlations among studied proteins as well as the relationships between the expression of Cx26, Bax, Bcl-xL and clinicopathological features were analyzed. RESULTS: Both normal epithelial cells and carcinoma cells expressed Cx26, Bax and Bcl-xL, but Cx26 in cancer cells showed aberrant, mainly cytoplasmic staining. Expression of Cx26, Bax and Bcl-xL was observed in 55.9%, 55.5% and 72.4% of evaluated colorectal cancers respectively. We found the positive correlation between Cx26 and Bax expression (r= 0.561, P<0.0001), Cx26 and Bcl-xL (P=0.409, P<0.0001) as well as between Bax and Bcl-xL (P=0.486, P<0.0001). Association of Cx26, Bax and Bcl-xL expression with histological G2 grade of tumors was noted (P<0.005, P<0.001 and P<0.002 respectively). CONCLUSION: Cytoplasmic presence of Cx26 and its association with apoptotic markers could indicate a distinct role from physiological functions of Cx26 in cancer cells and it could suggest that connexins might be a target point for modulations of apoptosis with therapeutic implications.

CO-EXPRESSIONS OF SURVIVIN GENE, BCL-2 AND BAX PROTEINS IN OVARIAN CARCINOMA

Objective To characterize the cellular properties of ovarian cancer, we examined the correlation between the expression of apoptosis-related gene survivin and those of Bcl-2 and Bax proteins. Methods Expressions of survivin mRNA, and Bcl-2 and Bax proteins in 35 cases of ovarian carcinoma, 10 cases of borderline carcinoma, 10 cases of benign tumors and 10 cases of normal tissue were evaluated by reverse transcription polymer-ase chain reaction (RT-PCR) and immunohistochemistry SABC method, respectively. Results Expression of survivin gene was detected in a significantly greater proportion in ovarian carcinoma and borderline carcinoma than those in benign tumors and normal tissues. Although there was no relationship between expression of survivin gene and FIGO stage, histologic grade, pathological type and lymphatic metastasis, expressions of Bcl-2 and Bax proteins were positively and negatively correlated with that of survivin gene, respectively. Conclusion Survivin may play an important role in pathogenesis of ovarian carcinoma, with a synergistic role of apoptosis-related gene Bcl-2 protein and an antagonistic role of Bax protein in formation and progression of ovarian carcinoma.

促红细胞生成素对低氧培养的海马神经元凋亡的影响

目的探讨促红细胞生成素(EPO)对低氧条件下原代培养的海马神经元凋亡的影响及其可能机制。方法培养7 d的大鼠海马神经元随机分为常氧对照组、低氧对照组和重组人促红细胞生成素(rHuEPO)低氧处理组(简称rHuEPO处理组,又分100 IU/mL、150 IU/mL两亚组),以四唑盐(MTT)比色法测定培养12、24、36h的细胞存活率,以Western blot蛋白印迹法测定上述时间点B细胞白血病-淋巴瘤-2(Bcl-2)和Bcl-2相关X蛋白(Bax)表达。结果 EPO可明显增加低氧培养的海马神经元存活能力(P<0.01),但两剂量组之间差异无统计学意义;rHuEPO处理组神经元Bcl-2表达比同时间点低氧对照组明显增多(P<0.05),而Bax表达比低氧对照组明显减少(均P<0.01)。结论 EPO可明显增加低氧培养的海马神经元存活能力,其作用机制可能通过调控Bcl-2和Bax表达实现。

Effect of Angelica keiskei chalcone on the expression of apoptosis-regulating proteins of mice hepatocarcinoma cells

Objective: The aim of our study was to investigate the effect of Angelica keiskei chalcone (AC) on the expression of Caspase-3 and Bax in mice hepatocarcinoma cells. Methods: Fifty mice inoculated hepatocarcinoma 22 cells were divided into five groups, 10 mice per group. Mice were given 5, 20, 40 mg/kg AC daily by mouth in low, middle and high dose groups respectively. Saline were given to the tumor control group by mouth. Twenty mg/kg cytoxan (CTX) by injection every other day were given to the positive control group. Ten days later, all mice were sacrificed. The levels of the Caspase-3 and Bax protein expression were measured by immunohistochemistry method and the proliferation activity of hepatocarcinoma cells was determined by MTT assay. Results: The expression level of Caspase-3 and Bax protein in tumor control group were 5.00% and 4.68%, respectively, and those of the high-dose group were 38.52% and 35.76%. The differences between two groups were significant (P < 0.05). The cell proliferation activity of tumor control group and high-dose group were 1.135 ± 0.032 and 0.716 ± 0.018. The difference was significant (P < 0.05). Conclusion: AC can increase the expression of Caspase-3 and Bax protein, and inhibit the proliferative activity of mice hepatocarcinoma cells.

Induction of apoptosis in human liver carcinoma HepG2 cell line by 5-allyl-7-gen-difluoromethylenechrysin

AIM： To investigate the effect of 5-allyl-7-gen-difluoromethylenechrysin （ADFMChR） on apoptosis of human liver carcinoma HepG2 cell line and the molecular mechanisms involved.METHODS： HepG2 cells and L-02 cells were cultured in vitro and the inhibitory effect of ADFMChR on their proliferation was measured by MTT assay. The apoptosis of HepG2 cells was determined by flow cytometry （FCM） using propidium iodide （PI） fluorescence staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of ADFMChR on the proxisome proliferator-activated receptor γ （PPARγ）, NF-κB, Bcl-2 and Bax protein expression of HepG2 cells were analyzed by Western blotting.RESULTS： MTT assay showed that ADFMChR significantly inhibited proliferation of HepG2 cells in a dose- dependent manner, with little effect on growth of L-02 cells, and when ICs0 was measured as 8.45 μmol/L and 191.55 μmol/L respectively, the potency of ADFMChR to HepG2 cells, was found to be similar to 5-fluorouracil （5-FU, ICso was 9.27 μmol/L）. The selective index of ADFMChR cytotoxicity to HepG2 cells was 22.67 （191.55/8.45）, higher than 5-FU （SI was 7.05 （65.37/9.27）. FCM with PI staining demonstrated that the apoptosis rates of HepG2 cells treated with 3.0, 10.0 and 30.0 μmol/L ADFMChR for 48 h were 5.79%, 9.29% and 37.8%, respectively, and were significantly higher when treated with 30.0 μmol/L ADFMChR than when treated with 30.0 μmol/L ChR （16.0%） （P 〈 0.05） and were similar to those obtained with 30.0 μmol/L 5-FU（41.0%）. DNA agarose gel electrophoresis showed that treatment of HepG2 cells with 10.0 μmol/L ADFMChR for 48 h and 72 h resulted in typical DNA ladders which could be reversed by 10.00 pmol/1 GW9662, a blocker of PPARy. Western blotting analysis revealed that aEer 24 h of treatment with 3.0, 10.0, 30.0 μmol/L ADFMChR, PPARy and Bax protein expression in HepG2 cells increased but Bcl-2 and NF-κB expression decreased; however, pre-incubation with 10.0 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 3.0, 30.0 μmol/L ADFMChR on PPARy and NF-KB protein expression in HepG2 cells.CONCLUSION： ADFMChR induces apoptosis of HepG2 cell lines by activating PPARγ, inhibiting protein expression of Bcl-2 and NF-κB, and increasing Bax expression.

白术多糖抗神经细胞缺氧性凋亡的机制研究

目的:探讨白术多糖抗神经细胞缺氧性凋亡的机制。方法:研究分为正常对照组、凋亡阳性组、白术多糖0.025g/L组、白术多糖0.05g/L组、白术多糖0.1g/L组、白术多糖0.25g/L组。采用"Neurobasal+B27"体外神经细胞无血清培养,免疫细胞化学鉴定神经细胞,MTT测定药物毒性,Rh-123染色流式细胞仪检测线粒体损伤,RT-PCR及免疫细胞化学测定Caspase-3、Bax、Bcl-2 mRNA及蛋白表达。结果:与凋亡阳性组比较,白术多糖在0.025g/L^0.1g/L降低缺氧的神经细胞线粒体损伤,0.025g/L^0.05g/L下调缺氧的神经细胞Caspase-3 mRNA的表达,0.05g/L下调缺氧的神经细胞Bax mRNA的表达,0.025g/L^0.25g/L下调缺氧的神经细胞Caspase-3和Bax蛋白表达,0.025g/L^0.25g/L上调缺氧的神经细胞Bcl-2蛋白表达,0.025g/L^0.05g/L提高Bcl-2/Bax mRNA及0.025g/L^0.1g/L提高Bcl-2/Bax蛋白的比例(P<0.05)。结论:白术多糖在一定发范围内能有效地抑制神经细胞缺氧性凋亡,其机理是降低凋亡基因及蛋白产生,上调抗凋亡蛋白产生,提高Bcl-2/Bax比例。

Relationship between expression of Bax and Bcl-2 proteins and apoptosis in radiation compound wound healing of rats

Objective: To study the relationship between the expression of Bax, Bcl 2 proteins, and apoptosis in radiation compound wound healing of rats. Methods: Apoptosis, Bax and Bcl 2 proteins were estimated by in situ terminal labeling (TUNEL) and immunohistochemical methods. Results: (1) Changes of the apoptosis in wound healing showed three typical characteristics: early occurrence, high frequency and delayed disappearance after radiation to rats when compared with those of simple wound group, which might be an important reason for radiation induced delayed wound healing. (2) The expression of Bax protein increased evidently with the increment of apoptosis and showed a good corresponding relationship with the apoptotic frequency in the process of wound healing. While the expression of Bcl 2 protein decreased obviously as the apoptosis reached a maximum and showed increasing tendency up to normal level when the apoptosis decreased distinctively. Conclusions: Bax and Bcl 2 proteins play an important role in the apoptotic regulation of radiation compound wound healing in rats.

Alterations of bcl-2, bcl x and bax protein expressions in area CA_3 of rat hippocampus following fluid percussion brain injury

Objective: To investigate the alterations of bcl 2 gene family in the area of CA 3 in rats and the molecular mechanism of neuronal apoptosis following traumatic brain injury. Methods: Male Sprague Dawley rats were subjected to lateral fluid percussion brain injury of moderate severity. bcl 2, bcl x, and bax protein expressions were detected by immunohistochemistry. Results: The immunoreactivity of bcl 2 and bcl x proteins decreased in the hippocampus ipsilateral impact site at 6 hours after injury, and this was the main cause of down regulation of the value of (bcl 2 +bcl x)/ bax. During the period of 1～3 days after injury, bax protein expression increased significantly, while bcl 2 and bcl x protein expressions decreased relatively slowly. The decreased value of (bcl 2+bcl x)/ bax was mainly due to the bax up regulation. Conclusions: The bcl 2 gene family is involved in neuronal apoptosis after traumatic brain injury, and the protein expression alterations of the bcl 2 gene family members lead to apoptosis of the neuronal cells.

Molecular mechanism of damage and repair of mouse thymus lymphocytes induced by radiation

OBJECTIVE: To investigate the role of apoptosis in radiation-induced mouse thymus lymphocyte damage and repair and provide the basis for understanding the molecular mechanism of radiation-induced lymphocyte damage and repair as well as the prevention and treatment of acute radiation sickness. METHODS: We studied the dynamic changes of apoptosis of mouse thymus lymphocytes and the expression of bax and bcl-2 gene products after 2, 4, 6 and 8 Gy of whole body gamma-irradiation using in situ terminal labeling, DNA electrophoresis and immunohistochemical techniques. RESULTS: At the early stage after irradiation, the percentage of apoptotic lymphocytes increased rapidly in accordance with the increasing of radiation doses, while the counts of the thymus and peripheral lymphocytes decreased sharply, showing an opposite change to lymphocyte apoptosis. After 6 Gy gamma-irradiation, typical morphological characteristics of thymus apoptotic lymphocytes in early, middle and late stages were found by transmission electron microscopy. The thymus lymphocytes displayed characteristic DNA ladders 4 hr and 8 hr after 2-6 Gy gamma-irradiation,using DNA gel electrophoresis techniques. Abnormal expression of bcl-2 and bax gene products were shown in irradiated lymphocytes. CONCLUSIONS: Apoptosis plays an important role in the process of radiation-induced mouse thymus lymphocyte damage and repair. Bcl-2 and Bax proteins may regulate the process of lymphocyte apoptosis.

Effect and mechanism of electronic magnetic pulse on peripheral lymphocytes in dogs

Objective To study the effects of electronic magnetic pulse (EMP) on peripheral lymphocytes in dogs and to explore the mechanisms of the biological effects of EMP.Methods T, TH and Ts lymphocytes were estimated by acid phosphatase cytochemistry. Apoptotic lymphocytes and Bax and Bcl-2 proteins related to apoptosis were observed with in situ terminal labeling and immunocytochemistry.Results Peripheral T lymphocyte subpopulations decreased obviously after EMP irradiation with (2 - 12) × 104 V/m. Apoptotic percentages of lymphocytes increased with the elevation of EMP doses. Ten days after different intensity radiation, the Bax protein was found to be elevated in accord with the peak value of lymphocyte apoptosis. However, Bcl-2 protein decreased obviously.Conclusion A definite field intensity EMP could induce injury to lymphocytes. Apoptosis induced by EMP is one of the main causes of peripheral lymphocyte death and leads to immunosuppression of the body.These results suggest that people should pay more attention to the injury caused by EMP, especially to the immunological functions of the body.

Reversal effect of bufalin on multidrug resistance in K562/VCR vincristine-resistant leukemia cell line

OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.

Spinal cord decompression reduces rat neural cell apoptosis secondary to spinal cord injury

Objective： To determine whether spinal cord decompression plays a role in neural cell apoptosis after spinal cord injury. Study design： We used an animal model of compressive spinal cord injury with incomplete paraparesis to evaluate neural cell apoptosis after decompression. Apoptosis and cellular damage were assessed by staining with terminal deoxynucleotidyl transferase （TdT）-mediated deoxyuridine triphosphate nick-end labelling （TUNEL） and immunostaining for caspase-3, Bcl-2 and Bax. Methods： Experiments were conducted in male Sprague-Dawley rats （n-78） weighing 300-400 g. The spinal cord was compressed posteriorly at T10 level using a custom-made screw for 6 h, 24 h or continuously, followed by decompression by removal of the screw. The rats were sacrificed on Day I or 3 or in Week 1 or 4 post-decompression. The spinal cord was removed en bloc and examined at lesion site, rostral site and caudal site （7.5 mm away from the lesion）. Results： The numbers of TUNEL-positive cells were significantly lower at the site of decompression on Day 1, and also at the rostral and caudal sites between Day 3 and Week 4 post-decompression, compared with the persistently compressed group. The numbers of cells between Day 1 and Week 4 were immunoreactive to caspase-3 and B-cell lymphoma-2 （Bcl-2）-associated X-protein （Bax）, but not to Bcl-2, correlated with those of TUNEL-positive cells. Conclusion： Our results suggest that decompression reduces neural cell apoptosis following spinal cord injury.

Effect of Lichong decoction on expression of Bcl-2 and Bcl-2-associated X protein mRNAs in hysteromyoma model rat

OBJECTIVE:To study on effects of Lichong decoction on expression of apoptosis-controlling genes,Bcl-2 and Bcl-2-associated X protein(Bax) mRNAs in hysteromyoma tissue of the hysteromyoma model rat.METHODS:Fifty Wistar female rats were randomly divided into a normal group,a model group,a Lichong decoction group,a Guizifuling capsule group and a Mifepristone group.The hysteromyoma rat model was established by intraperitoneal injection of exogenous estrin and progestogens.Pathological examination of uterine tissue,uterine coefficient and uterine transverse diameter were made under optic microscope and expressions of Bcl-2 and Bax mRNAs in uterine tissue in the groups were detected with real-time fluorescent quantitative polymerase chain reaction(PCR) technique.RESULTS:After treatment,under microscope it was found that in the Lichong decoction group myometrium thinned,muscle fiber slightly overgrowth or long and thin,regular arrangement,inserting phenomenon of inner circular muscle and external longitudinal muscle was occasionally or not seen in the Lichong decoction group.The uterine coefficient and the uterine transverse diameter significantly decreased(P<0.01),and Bcl-2 mRNA expression significantly decreased(P<0.01) and Bax mRNA expression significantly increased in hysteromyoma tissue(P<0.01) in the Lichong decoction group as compared with the model group.CONCLUSION:Therapeutic effects of Lichong decoction on hysteromyoma is related with decrease of Bcl-2 mRNA expression and increase of Bax mRNA expression.