• Molecules and Cells
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• v.24 no.3
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• pp.378-387
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• 2007

The Bcl-2 family of proteins interacts at the mitochondria to regulate apoptosis. However, the anti-apoptotic Bcl-2 and $Bcl-X_L$ are not completely localized to the mitochondria. In an attempt to generate Bcl-2 and $Bcl-X_L$ chimeras that are constitutively localized to the mitochondria, we substituted their C-terminal transmembrane tail or both the C-terminal transmembrane tail and the adjacent loop with the equivalent regions from Bak or Bax mutant (BaxS184V) as these regions determine the mitochondrial localization of Bak and Bax. The effects of these substitutions on subcellular localization and their activities were assessed following expression in HeLa and CHO K1 cells. The substitution of the C-terminal tail or the C-terminal tail and the adjacent loop of Bcl-2 with the equivalent regions from Bak or the Bax mutant resulted in its association with the mitochondria. This change in subcellular localization of Bcl-2 chimeras triggered cells to undergo apoptotic-like cell death. The localization of this Bcl-2 chimera to the mitochondria may be associated with the disruption of mitochondrial membrane potential. Unlike Bcl-2, the loop structure adjacent to the C-terminal tail in $Bcl-X_L$ is crucial for its localization. To localize the $Bcl-X_L$ chimeras to the mitochondria, the loop structure next to the C-terminal tail in $Bcl-X_L$ protein must remain intact and cannot be substituted by the loop from Bax or Bak. The chimeric $Bcl-X_L$ with both its C-terminal tail and the loop structure replaced by the equivalent regions of Bak or Bax mutant localized throughout the entire cytosol. The $Bcl-X_L$ chimeras that are targeted to the mitochondria and the wild type $Bcl-X_L$ provided same protection against cell death under several death inducing conditions.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.2
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• pp.118-125
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• 2005

Purpose: The expression of apoptosis-related genes, such as survivin, bcl-2, and bax has been examined in the human osteosarcoma and then evaluated the correlation with clinical data of patients. Materials and Methods: Fifty human osteosarcoma specimens were established from incisional biopsy and examination of survivin, bcl-2, and bax by immunohistochemical study was performed. We investigated the correlation of survivin, bcl-2, bax and their two or three combined expressions with clinical data including the response of chemotherapy, local recurrence, distance metastasis, and oncologic outcome. Results: Survivin was showed in 26 cases (52%), bcl-2 in 23 cases (46%), and bax in 21 cases (42%) osteosarcoma. And coexpression of survivin and bcl-2 was showed in 19 cases (38%), survivin and bax in 13 cases (26%), bcl-2 and bax in 8 cases (16%), and all three expression was showed in 8 cases (16%). There was no correlation between their apoptosis related gene and histologic difference, the presence of local recurrence and distant metastasis. Whereas neoadjuvant chemotherapy response correlated with bcl-2 expression (P=0.04), and survivin and bcl-2 coexpression (P=0.044) with poor chemoresponse. The rate of died of disease was correlated with bcl-2 (P=0.001), survivin and bcl-2 coexpression (P=0.027) with bad outcome. Survival curves of bcl-2 (P=0.0075), survivin and bcl-2 (P=0.0012) was showed negative correlation in the Kaplan-Meier method. Conclusion: The apoptosis related gene expression was relatively high in osteosarcoma, bcl-2 expression was correlated with poor chemotherapy response and poor survival rate, but survivin was correlated with this oncologic outcome only in the bcl-2 coexpression. The examination of immunohistochemical stain of apoptosis related gene in osteosarcoma could be helpful in the judgment of osteosarcoma prognosis.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.218-227
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• 2009

Purpose: To investigate the radiobiologic effects of neutron and X-ray irradiation on DU-145 prostate carcinoma cells by identifying the differences of HIF-$1\alpha$ expression and apoptosis. Materials and Methods: Nude mice were injected with the human prostate cancer cell line, DU-145, and then irradiated with 2 Gy and 10 Gy X-rays, or 0.6 Gy and 3.3 Gy neutrons, respectively. The mice were sacrificed at 24 hours and 120 hours after irradiation. The expression levels of HIF-$1\alpha$, Bcl-2 and Bax were compared with immunohistochemical staining and western blotting. The apoptotic indexes were compared with the Terminal deoxynucleotidyl biotin-dUTP nick and labeling (TUNEL) assay. Results: At day 1, HIF-$1\alpha$ and Bcl-2 expression decreased, while Bax expression and the number of TUNEL positive cells increased in neutron irradiated groups for the control and X-ray irradiated groups. The Bcl-2/Bax ratio was significantly lower in the neutron irradiated groups regardless of dose (p=0.001). The same pattern of the differences in the expressions of the HIF-$1\alpha$, Bcl-2, Bax, Bcl-2/Bax ratio, and apoptotic indexes were indentified at day 5. HIF-$1\alpha$ expression was related with Bcl-2 (p=0.031), Bax (p=0.037) expressions and the apoptotic indexes (p=0.016) at day 5. Conclusion: Neutron irradiation showed a decrease in HIF-$1\alpha$, Bcl-2 expression, and Bcl-2/Bax ratio, but increased Bax expression regardless of dose. This study suggests that the differences radiobiological responses between photon and neutron irradiation may be related to different HIF-$1\alpha$ expression and subsequent apoptotic protein expressions.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1590-1598
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• 2008

Cell proliferation and differentiation are critical processes in a developing fetal rat brain, during which programmed cell death (PCD) also plays an important role. One of the decisive factors for PCD is Bcl-2 family proteins, where Bax induces cell death, whereas Bcl-2 acts as an inhibitor of PCD. As maternal drinking is known to cause fetal alcohol syndrome (FAS) or malformation of the fetal brain during pregnancy, the objective of the present study was to investigate whether maternal ethanol exposure alters the PCD-related Bax and Bcl-2 protein expression during fetal brain development. Pregnant female rats were orally treated with 10% ethanol and the subsequent expressions of the Bax and Bcl-2 proteins examined in the fetal brain, including the forebrain, midbrain, and hindbrain, from gestational day (GD) 15.5 to GD 19.5, using Western blots, in situ hybridization, and immunohistochemistry. With regard to the ratio of Bcl-2 to Bax proteins (Bcl-2/Bax), the Bax protein was dominant in the forebrain and midbrain of the control GD 15.5 fetuses, except for the hindbrain, when compared with the respective ethanol-treated groups. Moreover, Bcl-2 became dominant in the midbrain of the control GD 17.5 fetuses when compared with the ethanol-treated group, representing an alternation of the natural PCD process by ethanol. Furthermore, a differential expression of the Bcl-2 and Bax proteins was found in the differentiating and migrating zones of the cortex, hippocampus, thalamus, and cerebellum. Thus, when taken together, the present results suggest that ethanol affects PCD in the cell differentiation and migration zones of the prenatal rat brain by modulating Bax and Bcl-2 expression in an age- and area-dependent manner. Therefore, this is the first evidence that ethanol may alter FAS-associated embryonic brain development through the alteration of Bax and Bc1-2 expression.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.671-676
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• 2006

We investigated the effect of gingerol (Zingiber officinale Roscoe, Zingiberaceae) on Bcl-2 and Bax expression in MDA-MB-231 human breast cell lines. The oleoresin from rhizomes of ginger contains [6]-gingerol (1-[4'-hydroxy-3'-methoxyphenyl]-5-hydroxy-3-decanone). We previously reported that [6]-gingerol inhibits cell proliferation in MDA-MB-231 human breast cancer cell lines. In this study, we examined protein and mRNA expression associated with cell apoptosis in MDA-MB-231 human breast cancer cell lines. We cultured MDA-MB-231 cells in presence of various concentrations 0, 2.5, 5 and $10\;{\mu}M$ of [6]-gingerol. Bcl-2 protein and its mRNA levels were decreased dose-dependently in cells treated with [6]-gingerol, but Bax protein and its mRNA levels were unchanged by [6]-gingerol treatment. Bcl-2/Bax ratio was decreased in a dose dependent manner treated with [6]-gingerol. Caspase-3 activity was significantly increased dose-dependently in cell treated with [6]-gingerol (p<0.05). In conclusion, we have shown that [6]-gingerol induces apoptosis in MDA-MB-231 human breast cancer cell lines.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.448-453
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• 1999

In ginsenoside Rh2-treated rat glioma C6Bu-1 cells, apoptotic morphological changes, such as cell shrinkage, chromatin condensation and pyknosis were confirmed by means of electron microscopy. To evaluate whether induction of apoptosis by ginsenoside Rh2 is mediated by the members of Bcl-2 family, we first established C6Bu-1 cells overexpressing Bcl-2. It was demonstrated that the expression of Bcl-2, Bcl-xL, and Bax was not altered in ginsenoside Rh2-treated C6Bu-1 overexpressing C6Bu-1 cells failed to prevent from ginsenoside Rh2-induced cell death. These results suggest the existence of other apoptotic pathway that requires induction of apoptosis by ginsenoside Rh2 rather than the pathway through Bcl-2, $Bcl-x_{L}$ or Bax in C6Bu-1 cells.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.3
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• pp.167-178
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• 2002

Objective : The present study was performed to investigate whether apoptosis occur in human embryos by annexin staining and detect the expression of Fas, Fas-ligand (FasL), Bax, and Bcl-2 in human fragmented embryos derived from IVF-ET by immunofluorescence and Western blot analysis. Materials and Methods: Using annexin staining, immunofluorescence and Western blot analysis on normal and fragmented embryos, we were able to detect apoptotsis and apoptotic gene products in fragmented embryos. Result: Phosphatidylserine (PS) translocation, the marker for apoptosis, were detected frequently in fragmented embryos. Bcl-2 and Bax protein were detected in both fragmented and non-fragmented embryos. When fragmented embryos compared to normal embryos, immunofluorescent intensity of Bcl-2 tended to be lower in fragmented embryos. Bax gene expression increased in the fragmented embryos compared to the normal embryos. This result supports a model in which the molar ratio of Bcl-2 to Bax determines whether apoptosis induced or inhibited in human embryo. Fas was highly expressed in human preimplantation embryos but not FasL. It suggests that embryo may undergo apoptosis by binding with FasL produced by follicular or immune cells. Conclusion: The over expression of Bax and Fas will trigger apoptosis to lead embryo fragmentation and change embryo to be nonviable.

• Korean Journal of Head & Neck Oncology
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• v.16 no.2
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• pp.161-166
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• 2000

Objective: The nm23 gene has been identified as a potential metastasis suppressor gene in various human neoplasms. Both Bcl-2, which promotes cell survival, and Bax, which promotes cell death, have been considered as major factors in controlling the apoptotic pathway. This study was carried out to determine whether these markers are useful in distinguishing potential intrinsic differences in tumor virulence of papillary thyroid cancers. Material and Method: The expressions of nm23, Bcl-2 and Bax have been evaluated using immunohistochemical techniques in 100 pure papillary thyroid cancers and 20 metastatic lymphnodes. The intensity of immnunoreactivity was graded on arbitrary four point scale(grade 0 or 1 : negative reactivity, grade 2 or 3 positive reactivity). The immunoreactivities were analyzed in relation to TNM atage, AMES score, local recurrence and distant metastasis, and that of metastatic LNs was compared with the tumors. Results: The expression of Bcl-2 and bax did not show any statistical differences by TNM stage, AMES score, recurrence, distant metastasis and also between the tumor and metastatic LN. However, the nm23 showed higher expression of Ki67 in distant metastasis than in control group and in metastatic LNs than in the tumors(p<0.05). Conclusion: Although the expression of Bcl-2 and Bax protein showed no correlation with clinical parameters representing tumor virulence, the nm23 expression could be an useful prognostic factor, especially in predicting nodal or distant metastasis in papillary thyroid cancer.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.2
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• pp.33-43
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• 2008

Objectives : Sunghyangjungki-san(Xingxiangzhengqi-san) is a herb decoction prescribed frequently for stroke patients. The present study investigated neuroprotective effects of Sunghyangjungki-san(Xingxiangzhengqi-san) against the ischemic damage of the rat brain. Neuronal cell death under the cerebral ischemia is distinguished with the delayed cell death through apoptosis. Consequently, the effects of Sunghyangjungki-san(Xingxiangzhengqi-san) was evaluated with Bax and Bcl-2 expressions as apoptosis related factors in the brain tissues. Methods : The ischemic damage was induced by the middle cerebral artery occlusion(MCAO) method in Sprague-Dawley rats. Water extract of Sunghyangjungki-san(Xingxiangzhengqi-san) was treated for 5 days after the MCAO. Neurological scores and infarct size with TTC were measured. Bax and Bcl-2 expressions in the brain tissues were observed with immunohistochemistry. Results : Sunghyangjungki-san(Xingxiangzhengqi-san) treatment improved neurological score significantly at 5 days after the MCAO. Sunghyangjungki-san(Xingxiangzhengqi-san) treatment decreased infarct size by the MCAO, but it was not significant statistically. Sunghyangjungki-san(Xingxiangzhengqi-san) treatment attenuated Bax positive neurons significantly in the cerebral penumbra and the caudate putamen. Bcl-2 positive neurons were increased, but not significant. Sunghyangjungki-san(Xingxiangzhengqi-san) treatment increased Bcl-2/Bax expression ratios significantly in the cerebral penumbra and the caudate putamen. Conclusions : These results suggest that Sunghyangjungki-san(Xingxiangzhengqi-san) has a neuroprotective effect on the stroke with modulation of apoptosis related factors.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.3
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• pp.155-160
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• 2020

Objective: The genes Bcl-2 and Bax play important roles in apoptosis. Many studies have shown that formalin has a strong deleterious effect on male fertility and can induce apoptosis. L-carnitine has been reported to potentially reverse the negative effects of formalin, leading to improved spermatogenesis. In this study, we examined the levels of expression of Bcl-2 and Bax in mice treated with formalin and L-carnitine. Methods: Thirty adult BALB/c mice were categorized into three groups. The mice in the control group (n = 10) were not injected with any substance. The mice in the second group (n = 10) received 10 mg/kg of formalin daily via an intraperitoneal injection, while those in the final group (n = 10) were intraperitoneally injected daily with a dose of 10 mg/kg of formalin and 100 mg/kg of L-carnitine. All mice were kept in isolated cages for 31 days. Results: The expression of Bax was significantly higher in the formalin-treated mice than in the mice of the control group, while the expression of Bcl-2 was significantly lower in the formalin-treated mice than in the control mice. Additionally, relative to control mice, Bcl-2 expression increased and Bax expression decreased in the mice administered both formalin and L-carnitine. Conclusion: In this study, L-carnitine was shown to augment Bcl-2 expression and to reduce Bax expression, indicating that this compound may inhibit apoptosis. Due to its positive effects, L-carnitine can be used as a prophylactic treatment for people who routinely come into direct contact with formalin as an occupational hazard.