Bcl-2与P53的相互作用

Bcl-2和P53蛋白以相互拮抗的方式在细胞周期调控、细胞凋亡以及肿瘤发生发展中扮演着重要的角色。P53可抑制bcl-2基因的转录;对Bcl-2蛋白进行修饰;还可直接与Bcl-2蛋白作用,抑制Bcl-2功能的发挥。Bcl-2则可以通过抑制P53对其下游基因的转录激活以及调节P53的蛋白定位等使P53功能受到抑制。     

良恶性脑肿瘤p53蛋白表达与细胞增殖和凋亡的研究

目的探讨脑肿瘤ｐ５３蛋白表达状况对其细胞增殖和凋亡的影响，及这些指标与脑肿瘤组织学类型和恶性程度的关系。方法对１０例对照脑组织和８０例脑肿瘤标本进行原位细胞凋亡及免疫组化标记。结果６９例脑肿瘤（８６．３％）表达ｐ５３蛋白，阳性细胞含量随肿瘤恶性程度升高而增加，对照组全部阴性。各肿瘤组增殖细胞核抗原和Ｋｉ－６７抗原阳性细胞密度均高于对照组，并随肿瘤恶性程度及ｐ５３蛋白表达升高而增加，凋亡细胞密度均低于对照组，并随肿瘤恶性程度及ｐ５３蛋白表达升高而降低。结论提示以上４种指标对评价脑肿瘤生物学行为有参考价值，脑肿瘤ｐ５３蛋白表达和功能异常与其细胞增殖及凋亡失衡有关，可能是原发性和转移性脑肿瘤发生发展的重要因素。     

Significance of tyrosine kinase activity on malign transformation of ovarian tumors: a comparison between EGF-R and TGF-alpha

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are members of the polypeptide growth factor family. The epidermal growth factor-receptor (EGF-R) is a receptor tyrosine kinase of the ErbB family. Many types of cancer, including ovarian cancer, display enhanced EGF-R immunoreactivity on their cell surface membranes. Also, an increase in TGF-alpha synthesis and secretion usually occurs in human carcinoma cell lines. In this study, we compared the immunoreactivities of TGF-alpha and EGF-R in ovarian tumors and related immunohistochemical findings to the histological type of the tumors. Formalin-fixed, paraffin wax-embedded tissue sections from 40 patients who had serous-mucinous borderline tumor and serous-mucinous adenocarcinoma of the ovary (n=10 each) were stained with hematoxylin-eosin and labeled for binding of primary antibodies against TGF-alpha and EGF-R using an avidin-biotin-peroxidase method. A semi-quantitative grading system was used to compare immunohistochemical labeling intensities. Increased immunoreactivity of EGF-R and moderate immunoreactivity of TGF-alpha was detected in adenocarcinomas. There was no significant difference in the immunoreactivity of TGF-alpha among the histologic types of ovarian tumors. The results of this study support the hypothesis that EGF-R may be a more useful marker than TGF-alpha in epithelial ovarian tumors.     

非小细胞肺癌中survivin上调与p53和Bcl-2的临床病理相关性

目的: 通过回顾性分析87例非小细胞肺癌(NSCLC)的临床病理资料,探索survivin、 p53和Bcl-2的临床病理相关性以及联合检测提示NSCLC预后的可能性.方法: 采用免疫组化SP法检测NSCLC中survivin、 p53和Bcl-2的表达.用Spearman等级相关系数检验其与NSCLC发生的相关性.结果: NSCLC组织的survivin蛋白阳性表达率为55.2%(48/87),阳性表达主要定位于NSCLC细胞质中.不同分期的NSCLC在survivin阳性表达率方面存在显著差异: III和IV期(中晚期)病例阳性率为71.1%(32/45),而I和II期(早中期)阳性率则为38.1%(16/42,P<0.01).不同原发肿瘤分期病例未显示出差异性survivin表达;而survivin表达则具有显著N分期相关性,无淋巴结转移(N0)病例的阳性率为43.5%(27/62),有淋巴结转移(N1和N2)病例则为84.0%(21/25,P<0.01).Survivin在鳞癌和腺癌中表达率分别为76.0%(38/50)和27.0%(10/37),其表达在两种病理类型间存在统计学差异(P<0.01).NSCLC组织的p53蛋白阳性表达率为64. 6%(56/87),阳性表达产物主要定位于NSCLC细胞质中.有淋巴结转移(N1和N2)病例阳性率(84.0%,21/25)显著高于无淋巴结转移病例(54.8%) (34/62,P<0.01).而且p53表达同时还具有组织类型相关性,鳞癌病例阳性率(76.0%,38/50)显著高于腺癌病例(27.0%) (10/37,P<0.01).NSCLC组织的Bcl-2蛋白阳性表达率为56.3%(49/87),阳性表达产物定位于NSCLC细胞质和细胞核中.有淋巴结转移(N1-2)病例阳性率(48.0%,12/25)明显高于无淋巴结转移病例(22.6%) (14/62,P<0.01).结论: Survivin上调显示出与NSCLC的临床病理相关性,同时survivin与p53和Bcl-2在NSCLC中也具有一定的临床病理相关性.[     

子宫内膜样腺癌Bax与p53表达的意义

目的探讨Bax和p53蛋白在子宫内膜样腺癌发生、发展中的作用.方法通过免疫组化SP法检测49例子宫内膜样腺癌石蜡标本的Bax和p53蛋白表达.结果子宫内膜样腺癌组和对照组Bax表达率分别为44.9%和77.1%(P<0.05).p53蛋白在对照组无表达,在子宫内膜样腺癌组13例表达阳性(26.5%),p53阳性率及表达强度与细胞分化不良相关.结论子宫内膜样腺癌Bax表达减少,可能导致线粒体介导的凋亡过程减弱,p53过度表达提示细胞的恶性程度高和预后不良.     

磷酸化修饰对p53线粒体作用的影响以及与卵巢癌顺铂耐药的关系

目的探讨磷酸化修饰对p53直接线粒体转移的影响以及在顺铂诱导的卵巢癌细胞凋亡中的作用以及与卵巢癌顺铂耐药的关系。方法应用Western Blot检测顺铂作用前后卵巢癌顺铂敏感细胞OV2008、A2780s和顺铂耐药细胞C13＊、A2780cp的线粒体和细胞浆中Smac蛋白含量以及线粒体和全细胞中磷酸化p53（P-p53）的含量,并应用Hoechst染色法检测卵巢癌细胞的凋亡率。结果顺铂能引起卵巢癌敏感细胞OV2008、A2780s线粒体释放Smac至胞浆并引起细胞凋亡,但在C13＊和A2780cp中无此反应。顺铂处理后进入卵巢癌敏感细胞线粒体中的p53蛋白为磷酸化的p53。结论顺铂能引起p53转移至线粒体并导致卵巢癌敏感细胞线粒体释放Smac至胞浆,促进卵巢癌细胞的凋亡,并且磷酸化修饰作用可以影响p53的直接线粒体功能,与卵巢癌化疗耐药有关。     

Apoptosis and proliferation related molecules (Bcl-2, Bax, p53, PCNA) in papillary microcarcinoma versus papillary carcinoma of the thyroid

AIM: To gain a better insight into the differences in biological behaviour between papillary microcarcinoma (PMC) and clinically evident papillary thyroid carcinoma (PTC). METHODS: Immunohistochemical analysis of apoptosis related molecules (Bcl-2, Bax, p53) and proliferation related marker (PCNA) in 39 archival cases of PMC and 46 cases of PTC. RESULTS: Bcl-2 and Bax were expressed in most PMCs and PTCs. The average Bcl-2 staining score did not differ significantly between PMCs and PTCs (p > 0.05), but the average Bax score was significantly lower in PMCs (p < 0.05). The Bcl-2/Bax ratio was significantly higher in PMCs than in PTCs (p < 0.05). The expression of p53 was similar in PMCs and PTCs, without a correlation with clinical data, but was associated with high Bax expression (p < 0.05) in these cases in both groups. Non-malignant tissue expressed only Bcl-2, but not p53 or Bax. PCNA expression was significantly lower (p < 0.05) in PMC than in PTC and positively correlated with tumour size (p < 0.05). CONCLUSIONS: The higher Bcl-2/Bax ratio and lower proliferative activity in PMC suggest differences from PTC in the balance between apoptosis and proliferation. However, the presence of p53 and Bax in PMC indicates malignant potential, and thus PMC should be treated with caution.     

MYC‐driven malignant transformation of mature murine B cells requires inhibition of both intrinsic apoptosis and p53 activity

Increased expression of the oncogene MYC is a common feature of many B‐cell malignancies, however MYC overexpression by itself is not sufficient for transformation, and additional genetic events are required, although the exact nature of these remains unknown. In patients and in transgenic mouse models, oncogenic transformation may occur in B cells at various differentiation stages interacting with complex microenvironments. B‐cell oncogenesis often occurs after prolonged periods of time, making it difficult to accurately identify the genetic events required for transformation. An in vitro system, where malignant transformation of primary B cells could be analyzed, would facilitate the identification of genetic events required for transformation. Here, we describe such a system and show that primary murine B cells rapidly become transformed upon forced expression of MYC, in conjunction with simultaneous inhibition of the ARF/p53 axis via overexpression of BMI1, as well as through downregulation of p19^ARF or expression of a dominant‐negative p53 and suppression of intrinsic apoptosis through overexpression of BCLXL or MCL1. Established tumor cells remained addicted to expression of the lymphoma‐inducing genes. In mice, transformed cells rapidly established fatal B‐cell lymphomas. Our results suggest that transformation of normal mature B cells into lymphomas can occur as a consequence of three defined events.     

SLE患者淋巴细胞Fas、Bcl-2、p53与Cmyc基因表达

凋亡基因Fas、抗癌基因p53与癌基因Bcl-2、Cmyc等与细胞凋亡密切相关,与疾病的发生、发展有一定的关系,系统性红斑狼疮(SLE)是一种自身免疫性疾病,为了探讨SLE与凋亡基因、癌基因的关系,我们采用简易原位杂交法对正常人与患者淋巴细胞的4种基因成批同时进行检测,并分别设探针对照,dig-AP对照,报道如下.     

猕猴早期胚胎脑的发育与凋亡相关蛋白p53和Bcl-2的表达

为了检测p53、Bcl-2在猕猴胚胎脑中的表达,探讨灵长类胚脑发育过程中生存与凋亡的基因调控规律,我们通过建立猕猴早孕模型,获取早期胚胎,并采用单克隆抗体链菌素亲生物蛋白过氧化酶(SP)免疫组织化学方法,检测了p53和Bcl-2蛋白在猕猴胚胎脑中的表达。结果显示,在猕猴25d、40d和55d胚胎脑均检测到p53和Bcl-2免疫反应阳性神经细胞;随着胎龄的增加,p53和Bcl-2免疫反应阳性表达率逐渐增大。上述结果表明在早期猕猴胚胎脑发育的不同时期均有p53和Bcl-2蛋白表达,这一对相互制约的凋亡相关蛋白在早期胚胎脑发育过程中表达逐渐增加,共同调控脑的发育。     

大肠肿瘤中抑凋亡基因bcl－2和p53蛋白产物的表达和意义

用免疫组化方法观察４５例大肠腺瘤和６１例大肠腺癌中ｂｃ１－２和ｐ５３蛋白的表达。结果显示：正常大肠粘膜中ｂｃ１－２和ｐ５３均未见表达，而大肠腺瘤及大肠腺癌阳性率均较正常组织明显增加（Ｐ＜０．０１）．大肠腺瘤中ｂｃ１－２表达位于不典型增生较重区域。大肠腺瘤ｐ５３表达随腺瘤直径增加而增加，其中≥２０ｍｍ组阳性率显著高于＜１０ｍｍ组（ｐ＜０．０５）。ｐ５３蛋白阳性率也随不典型增生程度增加而增高。ｐ５３表达与大肠腺癌分化程度及Ｄｕｋｅｓ分期有关。大肠腺瘤中ｂｃ１－２和ｐ５３蛋白的表达呈负相关。结果表明，ｂｃ１－２蛋白表达对大肠腺瘤的增殖有一定意义，ｐ５３在大肠腺瘤癌变和大肠腺癌进展中起重要作用。     

Clinicopathological and prognostic significance of p53, Ki-67, and Bcl-2 expression in Tunisian gastric adenocarcinomas

Gastric carcinoma (GC) is a highly aggressive malignancy with poor prognosis. It is widely accepted that malignancy results from abnormal cell growth due to dysregulation of the balance between cell proliferation and apoptosis. Our study aimed to investigate the clinicopathological and prognostic significance of p53, Ki-67, and Bcl-2 in Tunisian GC patients by immunohistochemistry. It was observed that the older patients showed p53 overexpression compared with the younger patients (p < 0.05). There was higher p53 expression in the intestinal-type compared with the diffuse-type (p < 0.05), and in well/moderate differentiated than in poor differentiated tumors. The expression of Ki-67 was positively associated with tumor size and venous invasion (p < 0.05). Bcl2 expression occurred in male patients and correlated with depth of invasion (p = 0.02). A Kaplan–Meier analysis indicated an inverse correlation between p53 and Ki-67 expression and the overall survival. Multivariate analysis revealed that the tumor site, Ki-67 and p53 expression were independent prognostic factors for gastric carcinomas (p < 0.05). Finally, combined expression of p53, Ki-67 and Bcl-2 showed that the group of patients with tumors p53+/Ki-67+/Bcl2− had aggressive behavior and poor prognosis (p log rank = 0.000). In summary, our data indicated that the expression of p53, Ki-67, and Bcl-2 may provide useful information for identifying patients with aggressive behavior and poor prognosis of GC.     

中药髓复康对恒河猴脊髓半横断后凋亡相关蛋白表达的影响

目的:探讨中药髓复康(SFK)对恒河猴脊髓半横断后凋亡相关蛋白(Bcl-2、Bax和p53)表达的作用及其机理。方法:实验选用8岁恒河猴14只,随机分为中药治疗组6只、横段脊髓模型组6只、正常对照组2只,采用双盲法复制脊髓T12右侧半横断损伤模型。灌喂SFK溶液1月后,实验恒河猴麻醉、以损伤部位为中心切取长1cm的脊髓,采用常规SABC免疫组织化学方法检测凋亡相关基因Bcl-2、Bax和p53蛋白表达,并对结果进行定性、定位、图像分析和统计学处理。结果:脊髓Bax免疫组织化学阳性细胞的平均光密度(MOD)模型组略高于正常对照组,中药组明显低于模型组(P0.05)。脊髓Bcl-2免疫组织化学阳性细胞面数密度(NA),中药组明显高于模型组(P0.05)。脊髓Bcl-2免疫组织化学阳性细胞的MOD模型组略高于正常对照组,中药组略高于模型组。脊髓p53免疫组织化学阳性细胞NA,模型组明显高于正常对照组(P0.05),中药组明显低于模型组(P0.05)。脊髓p53免疫组织化学阳性细胞的MOD模型组明显高于正常对照组(P0.05),中药组明显低于模型组(P0.05)。结论:髓复康可以促进Bcl-2蛋白表达,抑制Bax、p53蛋白表达和抑制神经元凋亡,对脊髓神经损伤具有保护作用。     

粉防己碱对缺血-再灌注损伤大鼠心肌细胞凋亡及Bcl-2/Bax蛋白表达的影响

目的探讨粉防己碱对缺血-再灌注损伤大鼠心肌细胞凋亡及Bcl-2/Bax蛋白表达的影响。方法结扎大鼠左冠状动脉前降支（LAD）30min后松开,再灌注24h建立心肌缺血-再灌注损伤模型。将48只雄性SD大鼠随机分为：假手术组（Sham组）,缺血-再灌注损伤组（IRI组）,粉防己碱预处理组（Tet组）。再灌注结束后检测血清肌酸激酶同工酶MB（CK-MB）和心肌梗死范围（IS/AAR,%）。应用原位末端标记法（TUNEL法）检测各组凋亡细胞,计算凋亡指数（AI）,应用免疫组化法检测心肌Bcl-2、Bax蛋白表达,计算Bcl-2/Bax值,进行组间比较。结果与IRI组相比,Tet可明显降低CK-MB值（976.57±160.69）vs（1910.38±221.10）U/L,P〈0.01,减小心肌IS/AAR%,（23.28±4.38）%vs（43.76±6.30）%,P〈0.01。与IRI组比较,粉防己碱预处理可显著减少心肌细胞凋亡,AI显著降低（8.62±2.45%vs19.36±5.28%,P〈0.01）。粉防己碱预处理使Bcl-2表达增加,Bax表达下降,Bcl-2/Bax值显著升高（P〈0.01）。结论粉防己碱能明显抑制缺血-再灌注损伤引起的心肌细胞凋亡,其作用机制可能与促进Bcl-2蛋白表达,减少Bax蛋白表达、升高Bcl-2/Bax比值有关。     

Bcl-2, tissue transglutaminase and p53 protein expression in the apoptotic cascade in ribs of premature infants

Apoptotic cells of the human growth plate have not previously been demonstrated in situ. We have investigated the distribution of apoptotic cells in costosternal growth plates and bone of premature infants aged 4–11 d with a gestational age of ∼ 26 wk. In addition, we investigated the immunolocalisation of apoptosis-related proteins within the growth plates and associated bone. A proportion of late hypertrophic chondrocytes and osteocytes within newly formed primary spongiosa showed evidence of highly fragmented DNA. The incidence of osteocyte apoptosis decreased as the distance from the chondroosseous junction increased. Tissue transglutaminase (tTG) expression was associated with apoptosis of osteocytes and hypertrophic chondrocytes. In contrast the presence of tTG was demonstrated in osteoblasts and bone lining cells but it did not colocalise with evidence of apoptosis. The anti-apoptotic gene product Bcl-2 was absent from the growth plate but was present in osteocytes. Visual assessment indicated a greater occurrence of the protein in cells occupying regions of low apoptosis. P53 was not demonstrated in the growth plate or bone. These findings would indicate that human growth plate chondrocytes appear to show little provision for ensuring cell longevity. In contrast osteocyte apoptosis appears negatively correlated with the skeletal distribution of Bcl-2 protein in the human infant, implying a potential selective vulnerability in individual cells. Lack of Bcl-2 and the high incidence of osteocyte apoptosis in the more rapidly remodelling bone of the human infant suggest a potential role of osteocyte apoptosis in the remodelling process.     

Prognostic significance of Ki-67, p53, and Bcl-2 expression in prostate cancer patients with lymph node metastases: A retrospective immunohistochemical analysis

The prognostic significance of Ki-67, p53, and Bcl-2 expression was evaluated in prostate cancer patients with lymph node metastases. Immunohistochemical staining of archived material obtained from 56 patients was performed by the streptavldin-biotin method. Univariate survival analysis showed that a Ki-67 labeling index (Ki-67 LI) of ≥8.4 in the primary tumor identified a group of patients with a significantly poorer prognosis (P<0.001). Furthermore, a Ki-67 LI of ≥8.7 in the nodal metastatlc tumor was also associated with a poorer prognosis (P<0.01). Multivariate analysis showed that the Ki-67 LI of primary tumors (P<0.01) and lymph node metastases (P<0.01) had independent prognostic value. p53 and Bcl-2 expression had no prognostic value in patients with prostate cancer and lymph node involvement. The Ki-67 LI has more prognostic value than p53 and Bcl-2 expression for patients with prostate cancer that has spread to the lymph nodes.     

硫化氢对人PMN凋亡及P53/Bcl-2表达的影响

目的:研究硫化氢(H2S)对人中性粒细胞(PMN)凋亡及P53、Bcl-2表达的影响,以进一步探讨H2S抗脂多糖性肺损伤作用的机制。方法:采用体外分离和培养人血PMN。实验分3组,对照组:培养基中加入无菌生理盐水10mL/L;脂多糖(LPS)组:培养基中加入LPS100μg/L;LPS+硫氢化钠(NaHS)组:先LPS前1h向培养基中加入(1×10-5、1×10-4、1×10-3)mol/LNaHS。各组于24h后采用脱氧核苷酸末端转移酶介导的DNA原位末端标记技术(TUNEL)检测PMN凋亡情况;采用流式细胞术检测PMN中P53及Bcl-2蛋白的表达。结果:与对照组比较,LPS组PMN凋亡百分率和DNA断裂百分率均显著减少(均P0.05);与LPS组比较,LPS+NaHS(1×10-5)组PMN凋亡百分率和DNA断裂百分率均有所升高,但无显著差异(均P0.05),LPS+NaHS(1×10-4)组及LPS+NaHS(1×10-3)PMN凋亡百分率和DNA断裂百分率均明显增加,并呈剂量依赖性(均P0.01)。与对照组比较,LPS组P53蛋白表达量显著减少(P0.05);与LPS组比较,LPS+NaHS(1×10-5)组P53蛋白表达量无明显变化(P0.05),LPS+NaHS(1×10-4)组及LPS+NaHS(1×10-3)组P53蛋白表达量明显增多,并呈剂量依赖性(均P0.01);各组Bcl-2蛋白表达量无明显变化(P0.05)。PMN中P53蛋白表达量与凋亡百分率的相关分析结果显示二者具有明显正相关关系(r=0.75,P0.01)。结论:NaHS促进PMN凋亡的机制可能与其上调P53蛋白的表达有关,而与Bcl-2蛋白无关。