Clusterin在乳腺浸润性导管癌中的表达与临床特征关系的研究

乳腺癌的发生与细胞增殖和凋亡之间的平衡有着密切关系.Clusterin是近年新发现的凋亡相关因子，它与乳腺癌关系的研究国内未见报道。本研究检测Clusterin在43例乳腺癌中的表达，分析其与乳腺癌临床特征的关系，以阐明CIusterin在乳腺癌进展中的作用。     

Clusterin、Bcl-2在喉鳞状细胞癌中的表达及意义

目的:探讨聚集素(Clusterin)在正常喉黏膜上皮、喉鳞状细胞癌(喉癌)组织中的表达及其与Bcl-2、临床分期、临床病理因素的关系。方法:采用免疫组化染色法检测Clusterin,Bcl-2蛋白在61例喉鳞状细胞癌组织及Clusterin在10例喉正常黏膜组织中的表达情况,并结合临床病理资料进行统计分析。结果:Clusterin在喉正常黏膜上皮、喉癌组织中阳性表达率分别为10%(1/10)、91.80%(56/61)。Clusterin在喉癌组织中表达水平高于喉正常黏膜上皮组织(χ2=31.29,P<0.05),且在癌组织中的表达与肿瘤的分化程度、临床分期及Bcl-2的表达呈正相关(rs分别为0.5841、0.5140、0.4138,均P<0.05)。结论:Clusterin在喉癌中高表达且与Bcl-2的表达存在相关关系。两者协同可能在喉癌发生、发展中发挥抗凋亡作用。     

Clusterin solubility and aggregation in Creutzfeldt-Jakob disease

Prion protein (PrP^C) is a glycolipid-anchored cell membrane syaloglycoprotein that localizes in presynaptic membranes. PrP has the property of aggregating into amyloid fibrils and being deposited in the brains in cases with transmissible encephalopathies (TSEs), when PrP^C is converted into abnormal protease-resistant PrP (PrP^RES). Clusterin is a heterodimeric glycoprotein, the expression of which is enhanced in astrocytes in association with punctate-type PrP^RES deposits during TSE progression. In addition, clusterin co-localizes in PrP^RES plaques in several human TSEs, including Creutzfeldt-Jakob disease (CJD). Clusterin is up-regulated in the cerebral cortex and cerebellum in CJD as revealed by DNA micro-array technology. Clusterin expression was examined in seven sporadic cases of CJD (codon 129 genotype, PrP type: 4 MM1, 1 MV1, 1 MV2, 1 VV2) and three age-matched controls by immunohistochemistry, Western blotting and solubility. In addition to small punctate clusterin deposition in the neuropil, single- and double-labeling immunohistochemistry disclosed clusterin localization in PrP^RES plaques, which predominated in the cerebellum of cases MV1, MV2 and VV2. Moreover, clusterin in plaques, but not punctate clusterin deposits, was resistant to protease digestion, as revealed in tissue sections pre-incubated with proteinase K. Clusterin in CJD, but not clusterin in control brains, was partially resistant to protease digestion in Western blots of total brain homogenates immunostained with anti-clusterin antibodies, which were processed in parallel with Western blots to PrP, without and with pre-incubation with proteinase K. Protein aggregation was analyzed in brain homogenates subjected to several solvents. PrP was recovered in the deoxycholate fraction in control and CJD cases, but in the SDS fraction only in CJD, thus indicating differences in PrP solubility between CJD and controls. Clusterin was recovered in the cytosolic, deoxycholate and SDS fraction in both CJD and control cases, but only clusterin from CJD was recovered in the urea-soluble fraction and, especially, in the remaining pellet. These findings demonstrate the capacity of clusterin to form aggregates and interact with PrP^RES aggregates. The implications of this property are not known, but it can be suggested that clusterin participates in PrP clustering and sequestration, thus modifying PrP toxicity in CJD.     

Comparative responses of three rat strains (DA/Han,Sprague-Dawley and Wistar) to treatment with environmental estrogens

The rat uterotrophic assay is a widely used screening test for the detection of estrogenic, endocrine-disrupting chemicals. Although much attention has been paid to identifying protocol variables and reproducibility between laboratories the question whether toxicodynamic and toxicokinetic variations of different strains may affect their sensitivity to estrogenic stimuli has been rarely addressed. We have compared the estrogenic activity of the environmental chemicals genistein (GEN), bisphenol A (BPA) and p-tert-octylphenol (OCT) in DA/Han (DA), Sprague-Dawley (SD) and Wistar (WIS) rats after repeated oral application. Rats were treated per os for 3 days with different doses of these weakly estrogenic compounds and the potent reference estrogen ethinylestradiol (EE). Then uterine wet weight, thickness of the uterine epithelium, uterine gene expression of clusterin (CLU), and thickness of the vaginal epithelium were examined as parameters for estrogenic potency of the test compounds in the three strains of rats. The uterotrophic response to treatment with BPA, OCT and GEN was similar in the three strains, and allowed us to rank them as GEN being more potent than OCT, and BPA being the weakest estrogen. This was confirmed by analysis of other biological endpoints, despite some differences in the magnitude of their response among strains and to distinct compounds. For instance, the uterus wet weight response to EE treatment indicated lower sensitivity of SD rats than that of DA and WIS rats, but this was not observed for responses of the uterine or vaginal epithelium. Moreover, blood concentrations were assessed at the time of killing and related to biological responses: plasma levels of total and unconjugated BPA and GEN depended upon the dose administered and varied to some extent within treatment groups and among the three rat strains. However, there was no good correlation in the three strains between individual compound concentrations analysed 24 h after the last dose and the uterotrophic wet weights. Summarising our results, we conclude that the sensitivity of various biological endpoints can differ slightly between strains of rats. On the other hand, our data demonstrate that the choice of the rat strain does not lead to pronounced differences in the evaluation of estrogenic activities of chemicals, especially when different biological endpoints are included in the analysis.     

Caspase-3与Clusterin在血管瘤组织中的表达及其相关性研究

目的探讨半胱氨酸天冬氨酸蛋白酶-3（Caspase-3）与Clusterin的表达及其与血管瘤消退的关系。方法采用免疫组化SP法检测Caspase-3与Clusterin在34例血管瘤和6例正常皮肤组织中的表达。结果Caspase-3与Clusterin在34例血管瘤组织中阳性表达率,增生期分别为31.3%、81.3%,消退期分别为72.2%、38.9%,而在正常皮肤均不表达,其中,Caspase-3在增生期中的表达低于消退期,差异有统计有统计学意义（P〈0.05）,Clusterin在增生期中表达高于消退期,差异有统计学意义（P〈0.05）。结论Clusterin蛋白可能通过抑制细胞凋亡在血管瘤的发生发展中发挥重要作用,且其表达与Caspase-3的异常表达密切相关。     

Lunasin promotes apoptosis in human colon cancer cells by mitochondrial pathway activation and induction of nuclear clusterin expression

Lunasin is a naturally occurring peptide with arginine–glycine–aspartic acid motif associated to its reported biological activity. We aimed to determine the potential of lunasin from soybean to stimulate apoptosis in HT-29 colon cancer cells. Lunasin caused cytotoxicity to HT-29 cells and induced G2/M cell cycle arrest with simultaneous increased in p21 expression. Lunasin-induced apoptosis as evidenced by a twofold increase in the percentage of cells undergoing apoptosis, decreased Bcl-2:Bax ratio from 8.5 to 0.4, increased caspase-3 activity by 77% and increased expression of pro-apoptotic nuclear clusterin by five fold when compared to untreated cells. In conclusion, lunasin stimulated apoptosis in HT-29 cells by activating apoptotic mitochondrial pathways and inducing expression of the pro-apoptotic nuclear clusterin.     

食管鳞癌clusterin表达及其临床意义

目的:探讨食管鳞癌组织clusterin表达和单纯手术治疗前后外周血clusterin含量变化与食管鳞癌临床参数的相关性.方法:RT-PCR分析5对食管鳞癌及其远端切缘食管上皮中clusterin基mRNA表达水平;ELISA分析41例单纯手术治疗食管鳞癌患者治疗前后的血清clusterin蛋白表达水平及其与临床特征的相关性.结果:与正常食管上皮相比食管鳞癌组织中clusterin基因表达显著下降或缺失.食管鳞癌患者术前血清中clusterin含量明显低于术后血清含量(3.23 mg/Lvs 25.71 mg/L,P<0.0001).食管鳞癌患者术前血清clusterin含量与肿瘤大小相关(P<0.01),而与年龄、性别、分化程度、肿瘤分期、淋巴结转移.以及总蛋白、白蛋白、血糖、血脂和总胆红素浓度无关(r=-0.1334,-0.1602,0.2413,0.0389,-0.2882,均p>0.05).结论:clusterin基因在食管鳞癌组织中表达明显下调或缺失,血清clusterin含量明显降低,提示在食管鳞状细胞癌中clusterin基因可能具有潜在的抑癌基因作用,动态检测外周血clusterin含量有助于判断食管癌进展.     

Clusterin在人精子膜表面的表达及其意义

目的 探讨clusterin在人类精子中的表达及其意义.方法 从精子表面用1%TritonX-100提取及氯仿/甲醇分离疏水性的膜表面蛋白,用免疫印迹法检测精子表面是否存在大然clusterin蛋白.用免疫荧光方法确定clusterin在人精子膜表面的分布特点.结果 人精子膜表面及精浆中含有大量的clusterin,且clusterin仅分布于精子头部及顶体区域,而阴性对照组没有发现天然clusterin的存在.结论 人精子头部及顶体表面分布大量的clusterin,可能与精子成熟及精卵结合有关.     

聚集素与肿瘤

聚集素是近年新发现的凋亡抑制蛋白,它广泛表达于各种组织及体液中,并参与多种生理及病理过程,包括免疫调节、细胞黏附、脂质转运、组织重构、膜循环及细胞凋亡、细胞周期调节等。近年研究发现,聚集素选择性地表达于某些肿瘤组织而在正常成熟组织中低表达,对肿瘤发生、发展具有重要作用。因此,对聚集素的深入研究可为阐明人类肿瘤的发生机制及肿瘤的诊断、治疗提供一个新的方向。