Selective Suppression of a Subset of Bax-dependent Neuronal Death by a Cell Permeable Peptide Inhibitor of Bax, BIP

김수영,김현,선웅 한국통합생물학회 2008 Animal cells and systems Vol.12 No.4

Bax, a pro-apoptotic member of Bcl-2 family proteins, plays a central role in the mitochondria-dependent apoptosis. Apoptotic signals induce the translocation of Bax from cytosol into the mitochondria, which triggers the release of apoptogenic molecules such as cytochrome C and apoptosis-inducing factor, AIF. Bax-inhibiting peptide (BIP) is a cell permeable peptide comprised of five amino acids designed from the Bax-interaction domain of Ku70. Because BIP inhibits Bax translocation and Bax-mediated release of cytochrome C, BIP suppresses Bax-dependent apoptosis. In this study, we observed that BIP inhibited staurosporine-induced neuronal death in cultured cerebral cortex and cerebellar granule cells, but BIP failed to rescue granule cells from trophic signal deprivation-induced neuronal death, although both staurosporine-induced and trophic signal deprivation-induced neuronal death are dependent on Bax. These findings suggest that the mechanisms of the Bax activation may differ depending on the type of cell death induction, and thus BIP exhibits selective suppression of a subtype of Bax-dependent neuronal death. Bax, a pro-apoptotic member of Bcl-2 family proteins, plays a central role in the mitochondria-dependent apoptosis. Apoptotic signals induce the translocation of Bax from cytosol into the mitochondria, which triggers the release of apoptogenic molecules such as cytochrome C and apoptosis-inducing factor, AIF. Bax-inhibiting peptide (BIP) is a cell permeable peptide comprised of five amino acids designed from the Bax-interaction domain of Ku70. Because BIP inhibits Bax translocation and Bax-mediated release of cytochrome C, BIP suppresses Bax-dependent apoptosis. In this study, we observed that BIP inhibited staurosporine-induced neuronal death in cultured cerebral cortex and cerebellar granule cells, but BIP failed to rescue granule cells from trophic signal deprivation-induced neuronal death, although both staurosporine-induced and trophic signal deprivation-induced neuronal death are dependent on Bax. These findings suggest that the mechanisms of the Bax activation may differ depending on the type of cell death induction, and thus BIP exhibits selective suppression of a subtype of Bax-dependent neuronal death.

Bax 유전자 발현에 의한 전립선암 세포고사

곽 철,김인걸,구자현,정 현,이은식,이상은,이종욱 大韓泌尿器科學會 2003 Korean Journal of Urology Vol.44 No.9

Bax-induced cell death of Arabidopsis is meditated through reactive oxygen-dependent and -independent processes

Baek, Dong-won,Nam, Jae-sung,Koo, Yoon-Duck,Kim, Doh-Hoon,Lee, Ji-young,Jeong, Jae-Cheol,Kwak, Sang-Soo,Chung, Woo-Sik,Lim, Chae-Oh,Bahk, Jeong-Dong,Hong, Jong-Chan,Lee, Sang-Yeol,Maki Kawai-Yamada,Hi Plant molecular biology and biotechnology research 2004 Plant molecular biology and biotechnology research Vol.2004 No.-

An Arabidopsis protoplast system was developed for dissecting plant cell death in individual cells. Bax, a mammalian pro-apoptotic member of the Bcl-2 family, induces apoptotic-like cell death in Arabidopsis. Bax accumulation in Arabidopsis mesophyll protoplasts expressing murine Bax cDNA from a glucocorticoid-inducible promoter results in cytological characteristics of apoptosis, namely DNA fragmentation, increased vacuolation, and loss of plasma membrane integrity. In vivo targeting analysis monitored using jellyfish green fluorescent protein (GFP) reporter indicated full-length Bax was localized to the mitochondria, as it does in animal cells. Deletion of the carboxyl-terminal transmembrane domain of Bax completely abolished targeting to mitochondria. Bax expression was followed by reactive oxygen species (ROS) accumulation. Treatment of protoplasts with the antioxidant N-acetyl-L-cysteine (NAC) during induction of Bax expression strongly suppressed Bax-mediated ROS production and the cell death phenotype. However, some population of the ROS depleted cells still induced cell death, indicating that there is a process that Bax-mediated plant cell death is independent of ROS accumulation. Accordingly suppression of Bax-mediated plant cell death also takes place in two different processes. Over-expression of a key redox-regulator, Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) down-regulated ROS accumulation and suppressed Bax-mediated cell death and transient expression of Arabidopsis Bax inhibitor-1 (AtBI-1) substantially suppressed Bax-induced cell death without altering cellular ROS level. Taken together. our results collectively suggest that the Bax-mediated cell death and its suppression in plants is mediated by ROS-dependent and -independent processes.

자간전증 태반에서 14-3-3 단백과 Bax의 발현

박지권 ( Ji Kwon Park ),김선임 ( Seon Im Kim ),백원영 ( Won Young Paik ) 대한산부인과학회 2007 Obstetrics & Gynecology Science Vol.50 No.6

목적: 만성적인 저산소증과 관련된 자간전증이 합병된 임신의 태반에서 세포고사와 관련 있는 14-3-3 단백과 Bcl-2계 단백의 발현을 알아보고, 두 단백간의 상호작용을 보고자 하였다. 연구방법: 자간전증 임산부의 태반 5예와 정상 대조군 임산부의 태반 5예를 대상으로 Western blot 및 Immunoprecipitation related Western blotting을 시행하여 결과를 비교, 관찰하였다. 결과: Western blot에서 Bax와 14-3-3 zeta는 정상 대조군보다 자간전증 임산부의 태반에서 유의하게 증가된 소견을 보였다. Immunoprecipitation related Western blotting 에서 14-3-3 zeta와 Bax의 상호작용은 자간전증 임산부의 태반에서 유의하게 감소된 소견을 보였다. 결론: 정상 태반에 비해 자간전증 태반에서 Bax 발현의 유의한 증가는 태반에서의 세포고사 촉진인자로 Bax가 관여할 것으로 추측되며, 14-3-3 zeta와 Bax의 interaction의 유의한 감소는 자간전증 태반에서 활동성인 Bax의 양이 증가하여 세포고사를 유도하는 것으로 이해되어 진다. 향후 태반에서의 세포고사에서 14-3-3 단백으로부터 Bax를 해리시키는 기전에 관한 추가적인 연구가 필요하리라 사료된다. Objective: Purpose of our study was to examine the expression level of 14-3-3 proteins and Bcl-2 family and to estimate the interaction between 14-3-3 proteins and Bcl-2 family in normal and preeclamptic placenta. Methods: Placental tissues were sampled from preeclampsia with caesarean delivery (n=5) and normal pregnant women with caesarean delivery (n=5). Western blot and immunoprecipitation related Western blotting were performed on all placental samples. Unpaired Student t-test was used to determine the statistical significance. Results: Western blot analysis revealed that the expression of Bax and 14-3-3 zeta was significantly greater in the preeclamptic placenta than in the normal placenta. Immunoprecipitation related Western blotting revealed that the interaction between 14-3-3 zeta and Bax was significantly less in the preeclamptic placenta than in the normal placenta. Conclusion: Increased expression of Bax and reduced interaction (between) 14-3-3 zeta and Bax in preeclamptic placenta might influence pathogenesis or sequelae of preeclampsia. Further study is needed to identify the trigger that induces dissociation of Bax from 14-3-3 proteins.

자궁내막증식증과 자궁내막선암에서의 bcl - 2 와 bax 단백질의 발현

이병석(Byung Seok Lee),홍순옥(Soon Oak Hong),양우익(Woo Ick Yang),이지성(Jee Sung Lee),차동현(Dong Hyun Cha),조용선(Yong Seon Cho),김정연(Jeong Yeon Kim),박기현(Ki Hyun Park),조동제(Dong Jae Cho),송찬호(Chan Ho Song) 대한산부인과학회 2000 Obstetrics & Gynecology Science Vol.43 No.9

목적 : 자궁내막증식증과 자궁내막선암 조직에서 bcl-2와 bax 단백질의 분포를 조사하여 신생물을 형성하는데 있어서 어떠한 역할을 하는지 살펴보고자 한다. 방법 : 1992년부터 1997년 사이에, 연세대학교 의과대학 병리학교실의 수술적 병리조직 기록으로부터 포르말린 고정과 파라핀 포매를 거친 조직절편을 검색하였다. 선택된 예는 비정형성이 동반되지 않은 단순 및 복합성 자궁내막증식증이 30예, 비정형성이 동반된 증식증이 10예, 자궁내막선암 grade I이 23예, grade II가 15예, grade III가 11예이었다. 선택된 조직절편에 면역조직화학염색을 시행하여 bcl-2와 bax 단백질의 발현양상을 조사하였다. 결과 : Bcl-2는 비정형성을 동반하지 않은 자궁내막증식증 모두(100.0%)에서 발현되었다. 비정형성을 동반한 자궁내막증식증의 경우에 있어서는 bcl-2가 10예 중에서 7예(70.0%)에서 발현되었다. 평균 강도 및 평균 분포도는 비정형성을 동반하지 않은 경우가 더 높았다. Bax는 비정형성을 동반하지 않은 자궁내막증식증 30예중에서 29예(96.7%)에서 발현되었다. 비정형성을 동반한 자궁내막증식증에서는 10예중에서 6예(60.0%)에서 발현되었다. Bcl-2의 발현율, 평균 강도 및 염색에 양성인 종양 세포의 분획은 자궁내막선암에서 분화도가 진행될수록 하향 조절되었다. 그러나 bax의 경우에는 차이를 보이지 않았다. 결론 : Bcl-2와 bax는 자궁내막 전암 병소에서 변형된 세포가 계속 생존해 있도록 하는데 중요한 역할을 하는 것 같다. 또한 bcl-2는 자궁내막암 세포의 분화도와 관련이 있으며, 자궁내막암의 예후인자로서 이용될 수 있을 것으로 생각된다. Objective : To investigate the distribution of bcl-2 and bax proteins in the endometrial neoplastic tissues in order to find out the role of these two genes in causing the neoplasia.Methods: Formalin-fixed, paraffin-embedded tissue blocks were retrieved from the surgical pathology files of the Department of Pathology, College of Medicine, Yonsei University, for the period from 1992 through 1997. We selected cases of endometrial hyperplasia without atypia(n=30), hyperplasia with atypia(n=10), and endometrial adenocarcinoma, grade I(n=23), grade II(n=15), grade III(n=11). Immunohistochemical staining was performed to detect the expression of bcl-2 and bax proteins. Results : Bcl-2 was expressed in all cases of endometrial hyperplasia without atypia(100.0%). In endometrial hyperplasia with atypia, bcl-2 was expressed in 7 cases out of 10 cases(70.0%). The intensity of bcl-2 was stronger in hyperplasia without atypia. Bax was expressed in 29 cases out of 30 cases in endometrial hyperplasia without atypia(96.7%). In endometrial hyperplasia with atypia, bax was expressed in 6 cases out of 10 cases(60.0%). The expression, the intensity, and the percentage of positive tumor cells of bcl-2 were decreased as the grade advanced in endometrial adenocarcinoma. However, there was no difference in the expression of bax. Conclusion : Bcl-2 and bax may play a role in keeping transformed cells alive in premalignant endometrial lesion. Furthermore, bcl-2 may be involved in the differentiation of the endometrial cancer cells and may be used as a prognostic factor in endometrial cancer.

Different Expressions of HIF-1α, Bcl-2 and Baxin DU145 Prostate Cancer Cells Transplanted in Nude Mouse between X-Ray and Neutron Irradiation

Moonkyoo Kong(공문규),Jin Oh Kang(강진오),Sang Ki Kim(김상기),Dong Oh Shin(신동오),Seo Hyun Park(박서현),Chang Ju Kim(김창주),Hyun Kyung Chang(장현경) 대한방사선종양학회 2009 Radiation Oncology Journal Vol.27 No.4

Purpose: To investigate the radiobiologic effects of neutron and X-ray irradiation on DU-145 prostate carcinoma cells by identifying the differences of HIF-1α 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-1α, 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-1α 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-1α, Bcl-2, Bax, Bcl-2/Bax ratio, and apoptotic indexes were indentified at day 5. HIF-1α 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-1α, 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-1α expression and subsequent apoptotic protein expressions. 목 적: 전립샘암 세포주 DU 145에서 엑스선과 중성자선에 의한 HIF-1α와 아포프토시스 발현의 차이를 비교함으로써 엑스선과 중성자선의 방사선생물학적 차이의 기전을 알아보고자 한다. 대상 및 방법: 누드 마우스에 DU 145 전립샘암 세포주를 주입한 후 2 Gy 엑스선, 10 Gy 엑스선, 0.6 Gy 중성자선, 3.3 Gy 중성자선을 각각 조사했다. 엑스선을 조사한 군과 중성자선을 조사한 군에서 HIF-1α, Bcl-2, Bax, 아포프토시스 발현 정도를 면역조직화학 염색과 western blotting을 이용하여 비교하였다. 아포토시스의 정도는 terminal deoxynucleotidyl biotin-dUTP nick end labeling (TUNEL) 염색을 이용하여 비교하였다. 결 과: 방사선 조사 1일째, X선을 조사한 군과 비교했을 때, 중성자선을 조사한 군에서 HIF-1α와 Bcl-2의 발현은 감소하였고, Bax와 아포프토시스 세포의 수는 증가하였다. Bcl-2/Bax 비는 중성자선을 조사한 군에서 의미 있게 감소하였다. 이러한 HIF-1α, Bcl-2, Bax, Bcl-2/Bax 비, 아포프토시스 발현의 차이는 방사선 조사 5일째에도 동일하게 유지되어 나타났다. 또한, HIF-1α 발현은 방사선 조사 5일째 Bcl-2 (p=0.031), Bax (p=0.037), TUNEL (p=0.016) 발현과 연관성을 보였다. 결 론: 중성자선 조사한 경우 엑스선에 비해 HIF-1α와 Bcl-2 발현, Bcl-2/Bax 비가 감소하고, Bax 발현은 증가하였다. 중성자선 치료의 광자선과 다른 방사선생물학적인 반응은 HIF-1α와 그로 인한 아포프토시스 관련 단백질 발현의 차이와 연관성이 있을 것으로 생각한다.

Selective Suppression of a Subset of Bax-dependent Neuronal Death by a Cell Permeable Peptide Inhibitor of Bax, BIP

Kim, Soo-Young,Kim, Hyun,Sun, Woong The Korean Society for Integrative Biology 2008 Animal cells and systems Vol.12 No.4

Bax, a pro-apoptotic member of Bcl-2 family proteins, plays a central role in the mitochondria-dependent apoptosis. Apoptotic signals induce the translocation of Bax from cytosol into the mitochondria, which triggers the release of apoptogenic molecules such as cytochrome C and apoptosis-inducing factor, AIF. Bax-inhibiting peptide(BIP) is a cell permeable peptide comprised of five amino acids designed from the Bax-interaction domain of Ku70. Because BIP inhibits Bax translocation and Bax-mediated release of cytochrome C, BIP suppresses Bax-dependent apoptosis. In this study, we observed that BIP inhibited staurosporine-induced neuronal death in cultured cerebral cortex and cerebellar granule cells, but BIP failed to rescue granule cells from trophic signal deprivation-induced neuronal death, although both staurosporine-induced and trophic signal deprivation-induced neuronal death are dependent on Bax. These findings suggest that the mechanisms of the Bax activation may differ depending on the type of cell death induction, and thus BIP exhibits selective suppression of a subtype of Bax-dependent neuronal death.

근치적 방사선치료를 시행한 제2기의 자궁경부암 환자에서 p53과 Bax의 발현과 임상적 의의

최석진(Sukjin Choi),김헌정(Hunjung Kim),송은섭(Eunseop Song),김창영(Changyoung Kim),이미조(Meejo Lee),김우철(Woochul Kim),노준규(John J K. Loh) 대한방사선종양학회 2005 Radiation Oncology Journal Vol.23 No.2

목 적: 진행된 자궁경부암 환자에서 bax와 p53의 발현 빈도를 방사선치료를 받은 환자를 대상으로 예후인자 로서의 유용성을 알아보기 위하여 본 연구를 시행하였다. 대상 및 방법: 본 연구는 1996년 6월부터 2003년 12월까지 근치적 방사선치료를 받은 FIGO stage IIb의 자궁경부암 환자 65명을 대상으로 면역조직화학 염색을 시행하여 관찰된 bax와 p53의 발현과 환자의 5년 생존율과 무병생존율의 관계를 연구하였다. 결 과: 대상환자 65명에 대한 5년 생존율과 무병생존율은 각각 65.1%와 62.9%였다. p53에 대한 면역조직화학염색은 26.2%의 발현을 보였으며, 음성 환자 군과 양성 환자 군의 5년 생존율은 각각 66.6%와 61.1% (p=0.176)였으나, 무병생존율은 각각 72.1%와 50.9% (p=0.027)로 단변량분석에서 통계학적 차이를 보였다. 면역염색에 대한 bax의 발현은 52.3%에서 양성을 보였으며, 음성 환자 군과 양성 환자 군의 5년 생존율은 각각 68.8%와 63.6% (p=0.726)였으며, 무병생존율은 각각 68.1%와 64.1% (p=0.505)로 통계학적 차이가 없었다. 다변량분석에서는 p53 단백의 발현과 bax의 발현이 생존율에 의미 있는 영향을 주지 못했다. 그러나 p53+/ bax-의 면역화학염색 결과를 보인 9명의 환자에서 의미 있는 가장 낮은 무병생존율을 관찰할 수 있었다.결 론: p53과 bax의 발현은 단독적으로 방사선치료를 시행한 환자에서 유의성을 가지는 예후인자로 사용할수 없었다. 그러나 p53과 bax의 발현을 동시에 평가할 경우 유용한 예후 인자로서 임상적 유용성이 있을 것으로 생각한다. Purpose: The objective ot our study was to evaluate the Immunohistochemical expression 01 p53 and bax proteins as prognostic markers in FIGO stage lib invasive squamous cell carcinoma of Ihe uterine cervix. Malerials and Methods: Sixty-tive cases 01 squamous cell carcinoma of the cervix (stage lib) that were diagnosed from October 1996 to December 2003 were analyzed retrospectively for the bax and p53 expression. These expressions were determined immunohislochemically and they were correlated to the patients' ovemll survival and disease-tree survival. Resuns: The overall 5-year survival (OSI rate and the disease-free survival (DFSI rate were 65. t% and 62.9%, respectively. p53 and bax immunoreactivity was seen in 26.2% and 52.3% of cases, respectively, with vmiable levels 01 expression. On the univmiate analysis, only p53 positivily correlated wilh poor survival in DFS (log-rank test p=0.0271, but this significance was not maintained on multivariated analysis by Cox's regression. The nine cases With the Immunophenotype p53+/bax- had the poorest survival. Conclusion: Neither p53 nor bax expression are independent predictors ot the prognosis for stage lib cervical squamous cancers. Evaluation of p53 and bax co expression may aHect the clinical outcome and further investigation is needed.

Tumor-suppressor Protein p53 Sensitizes Human Colorectal Carcinoma HCT116 Cells to 17α-estradiol-induced Apoptosis via Augmentation of Bak/Bax Activation

Cho Rong Han(한초롱),Ji Young Lee(이지영),Dongki Kim(김동기),Hyo Young Kim(김효영),Se Jin Kim(김세진),Seokjoon Jang(장석준),Yoon Hee Kim(김윤희),Do Youn Jun(전도연),Young Ho Kim(김영호) 한국생명과학회 2013 생명과학회지 Vol.23 No.10

17α-estradiol (17α-E₂)의 에폽토시스 유도활성에 미치는 종양억제단백질 p53의 조절효과를 조사하고자, 17α-E₂에 의해 유도되는 에폽토시스 현상들을 인체 대장암 세포주 유래 클론인 HCT116 (p53+/+) 및 HCT116 (p53-/-) 세포에서 비교하였다. HCT116 (p53+/+) 및 HCT116 (p53-/-) 세포를 17α-E₂ (2.5~10 μM)로 처리하거나 혹은 HCT116 (p53+/+) 및 HCT116 (p53-/-) 세포를 10 μM 17α-E₂로 시간 별로 처리한 결과, HCT116 (p53+/+)에 있어서는 세포독성과 에폽토시스-관련 sub-G₁ peak의 비율은 처리농도와 시간에 의존적으로 나타났다. 그러나 HCT116 (p53-/-) 세포의 경우는 이러한 현상이 미약하게 나타났다. 17α-E₂에 의해 유도되는 비정상적 유사분열방추사 형성, 중기판 염색체 배열의 미완성, 이에 따른 유사분열정지(G₂/M arrest) 등의 현상은 HCT116 (p53+/+) 및 HCT116 (p53-/-) 세포에서 유사한 수준으로 나타났다. 이에 반해, 17α-E₂에 의해 유도되는 Bak과 Bax의 활성화, 미토콘드리아의 막전위 상실(Δψm loss), 그리고 PARP 분해 등의 현상은 HCT116 (p53-/-) 세포에 비해 HCT116 (p53+/+) 세포에서 훨씬 높은 수준으로 확인되었다. 아울러 17α-E₂로 처리된 HCT116 (p53+/+) 세포에서 확인되는 p53 (Ser-15)의 인산화 및 p53 수준의 증가와 일치하여, 세포 내의 p21및 Bax 수준도 현저히 증가하였다. 이때 17α-E2로 처리된 HCT116 (p53-/-) 세포에서는 p21 및 Bax의 발현수준이 매우 낮았다. 한편, 에폽토시스 억제단백질인 Bcl-2 단백질수준은 HCT116 (p53-/-) 세포에 비해 HCT116 (p53+/+) 세포에서 다소 낮았으나, 이러한 Bcl-2 단백질 수준은 17α-E₂ 처리 후에도 크게 변화하지 않는 것으로 나타났다. 이러한 결과들은 17α-E₂ 처리에 의해 유도되는 에폽토시스 유도 경로의 구성원들의 변화, 즉 비정상적 유사분열방추사 형성 및 이에 따른 유사분열정지(G2/M arrest), 뒤이은 Bak 및 Bax의 활성화, 미토콘드리아의 막전위 상실, 그리고 이에 수반되는 caspase cascade 활성화 및 PARP 분해로 진행되는 에폽토시스 현상들 중에서, Bak 및 Bax의 활성화 단계가 종양억제단백질 p53의 에폽토시스 증진 활성에 의해 양성적으로 조절되는 작용 타켓임을 보여준다. The regulatory effect of the tumor-suppressor protein p53 on the apoptogenic activity of 17α-estradiol (17α-E₂) was compared between HCT116 (p53+/+) and HCT116 (p53-/-) cells. When the HCT116 (p53+/+) and HCT116 (p53-/-) cells were treated with 2.5~10 μM 17α-E₂ for 48 h or with 10 μM for various time periods, cytotoxicity and an apoptotic sub-G₁ peak were induced in the HCT116 (p53+/+) cells in a dose- and time-dependent manner. However, the HCT116 (p53-/-) cells were much less sensitive to the apoptotic effect of 17α-E₂. Although 17α-E₂ induced aberrant mitotic spindle organization and incomplete chromosome congregation at the equatorial plate, G₂/M arrest was induced to a similar extent in both cell types. In addition, 17α-E₂-induced activation of Bak and Bax, Δψm loss, and PARP degradation were more dominant in the HCT116 (p53+/+) than in the HCT116 (p53-/-) cells. In accordance with enhancement of p53 phosphorylation (Ser-15) and p53 levels, p21 and Bax levels were elevated in the HCT116 (p53+/+) cells treated with 17α-E₂. The HCT116 (p53-/-) cells exhibited barely or undetectable levels of p21 and Bax, regardless of 17α-E₂ treatment. On the other hand, although the level of Bcl-2 was slightly lower in the HCT116 (p53+/+) than in the HCT116 (p53-/-) cells, it remained relatively constant after the 17α-E₂ treatment. Together, these results show that among the components of the 17α-E₂-induced apoptotic-signaling pathway, which proceeds through mitotic spindle defects causing mitotic arrest, subsequent activation of Bak and Bax and the mitochondria-dependent caspase cascade, leading to PARP degradation, 17α-E₂-induced activation of Bak and Bax is the upstream target of proapoptotic action of p53.

Gene Expression Profiling of Rewarding Effect in Methamphetamine Treated Bax-deficient Mouse

Ryu, Na-Kyung,Yang, Moon-Hee,Jung, Min-Seok,Jeon, Jeong-Ok,Kim, Kee-Won,Park, Jong-Hoon Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.4

Methamphetamine is an illicit drug that is often abused and can cause neuropsychiatric and neurotoxic damage. Repeated administration of psychostimulants such as methamphetamine induces a behavioral sensitization. According to a previous study, Bax was involved in neurotoxicity by methamphetamine, but the function of Bax in rewarding effect has not yet been elucidated. Therefore, we have studied the function of Bax in a rewarding effect model. In the present study, we treated chronic methamphetamine exposure in a Bax-deficient mouse model and examined behavioral change using a conditioned place preference (CPP) test. The CPP score in Bax knockout mice was decreased compared to that of wild-type mice. Therefore, we screened for Bax-related genes that are involved in rewarding effect using microarray technology. In order to confirm microarray data, we applied the RT-PCR method to observe relative changes of Bcl2, a pro-apoptotic family gene. As a result, using our experiment microarray, we selected genes that were associated with Bax in microarray data, and eventually selected the Tgfbr2 gene. Expression of the Tgfbr2 gene was decreased by methamphetamine in Bax knockout mice, and the gene was overexpressed in Bax wild-type mice. Additionally, we confirmed that Creb, FosB, and c-Fos were related to rewarding effect and Bax using immunohistochemistry.