AIB1影响卵巢癌预后及增强卵巢癌对顺铂抵抗的研究

据报道,乳腺癌扩增因子(AIB1)能促进乳腺癌的发生发展和转移。然而,AIB1和卵巢癌的发生发展关系尚不清楚。本研究提取了TCGA数据库中卵巢癌患者癌组织的m RNA表达数据,利用在线软件Kaplan-Meier plotter分别分析了aib1基因表达与卵巢癌患者以及经过顺铂治疗过的患者的总生存期(OS)、进展后生存期(PPS)和无进展生存期(PFS)之间的相关性。结果表明,无论在总的卵巢癌患者群体中还是在顺铂治疗后的群体中,aib1基因高表达患者的OS、PPS以及PFS都显著降低。在人卵巢癌细胞系(SKVO3)中,通过转染AIB1过表达质粒和小干扰RNA(si RNA),分别上调和下调AIB1表达来检测SKVO3对顺铂的敏感性。结果表明,上调AIB1表达抑制了SKVO3细胞对顺铂的敏感性,而下调AIB1表达促进了SKVO3细胞对顺铂的敏感性。进一步研究发现,AIB1高表达上调了卵巢癌细胞中B淋巴细胞瘤-2(BCL2)、B细胞淋巴瘤/白血病x基因长片段(BCL2L1)的表达,而干扰AIB1表达下调了细胞中BCL2、BCL2L1的表达。通过提取TCGA数据库中的卵巢癌患者癌组织m RNA表达数据,利用在线软件GEPIA分析了aib1基因m RNA表达与bcl2、bcl2l1基因m RNA表达的相关性。结果发现,aib1基因表达与bcl2、bcl2l1基因表达呈显著正相关。其结果进一步表明,AIB1可能调节BCL2和BCL2L1的表达。总之,AIB1能作为判断卵巢癌预后的标志物以及卵巢癌治疗的潜在分子靶点,并且抑制AIB1能够增强顺铂对卵巢癌的治疗效果。本研究为卵巢癌对顺铂抵抗的机制提供了新的见解,对克服卵巢癌化疗抵抗具有一定的价值。     

乳腺浸润性导管癌组织中AIB1 与Ki67的表达及临床意义

目的:探讨乳腺浸润性导管癌(IDC)中乳腺癌扩增性抗原1(AIB1)和增殖细胞核抗原(Ki67)蛋白的表达及临床意义。方法:选择2012年6月到2014年6月在我院经病理检查确诊为IDC患者的组织石蜡标本160例,采用链霉素-生物素(SP)免疫组化法检测标本中AIB1和Ki67蛋白的表达,多因素Logistic回归分析二者与IDC临床病理学特征的相关性。结果:AIB1、Ki67的阳性表达率分别为75.63%和80.63%。AIB1、Ki67的表达与淋巴结转移、组织学分级及TNM分期存在相关性(P0.05),且随组织学分级和TNM分期的增高,阳性表达率逐渐增高(P0.05),Ki67的表达水平随肿瘤变大,阳性率逐渐增加(P0.05)。淋巴结阳性组AIB1、Ki67的阳性表达率显著高于淋巴结阴性组(P0.05)。多因素Logistic回归分析显示,AIB1、Ki67的阳性表达是淋巴结转移、病理组织学分级及TNM分期的危险因素(P0.05)。结论:在IDC组织中AIB1和Ki67的阳性表达均增高,二者与IDC临床病理学特征有密切关系。     

Chaperonin CCT-Mediated AIB1 Folding Promotes the Growth of ERα-Positive Breast Cancer Cells on Hard Substrates

Clinical observations have revealed a strong association between estrogen receptor alpha (ERα)-positive tumors and the development of bone metastases, however, the mechanism underlying this association remains unknown. We cultured MCF-7 (ERα-positive) on different rigidity substrates. Compared with cells grown on more rigid substrates (100 kPa), cells grown on soft substrates (10 kPa) exhibited reduced spreading ability, a lower ratio of cells in the S and G2/M cell cycle phases, and a decreased proliferation rate. Using stable isotope labeling by amino acids (SILAC), we further compared the whole proteome of MCF-7 cells grown on substrates of different rigidity (10 and 100 kPa), and found that the expression of eight members of chaperonin CCT increased by at least 2-fold in the harder substrate. CCT folding activity was increased in the hard substrate compared with the soft substrates. Amplified in breast cancer 1 (AIB1), was identified in CCT immunoprecipitates. CCT folding ability of AIB1 increased on 100-kPa substrate compared with 10- and 30-kPa substrates. Moreover, using mammalian two-hybrid protein-protein interaction assays, we found that the polyglutamine repeat sequence of the AIB1 protein was essential for interaction between CCTζ and AIB1. CCTζ-mediated AIB1 folding affects the cell area spreading, growth rate, and cell cycle. The expressions of the c-myc, cyclin D1, and PgR genes were higher on hard substrates than on soft substrate in both MCF-7 and T47D cells. ERα and AIB1 could up-regulate the mRNA and protein expression levels of the c-myc, cyclin D1, and PgR genes, and that 17 β-estradiol could enhance this effects. Conversely, 4-hydroxytamoxifen, could inhibit these effects. Taken together, our studies demonstrate that some ERα-positive breast cancer cells preferentially grow on more rigid substrates. CCT-mediated AIB1 folding appears to be involved in the rigidity response of breast cancer cells, which provides novel insight into the mechanisms of bone metastasis.     

Overexpression and Gender-specific Differences of SRC-3 (SRC-3/AIB1) Immunoreactivity in Human Non–Small Cell Lung Cancer: An In Vivo Study

Steroid receptor coactivator-3 (SRC-3) has been reported to be overexpressed in the development and progression of many tumor types. SRC-3 has been detected in several lung cancer cell lines, but its expression and clinical significance in non–small cell lung cancer (NSCLC) remain unclear. In this study, 48 NSCLC tissues were collected and tissue microarrays were performed. The expression of SRC-3 was examined using nickel-intensified IHC. The results showed that of these 48 cases, 18 (37.5%) exhibited high levels of SRC-3 immunoreactivity, 23 (47.9%) exhibited moderate levels of SRC-3 immunoreactivity, and 7 (14.6%) were negative; thus, the total frequency of SRC-3 overexpression was 85.4% (41/48). This SRC-3 overexpression frequency was similar to the overexpression frequency observed for squamous cell carcinoma and adenocarcinoma (82.1% vs 90%) and for metastasis and non-metastasis patients (84.6% vs 85.7%). Data analysis demonstrated a significantly higher overexpression frequency in male patients compared with that in female patients (88.6% vs 76.9%). However, female patients tended to have higher expression levels of SRC-3, as measured by immunoreactivity, than male patients. These results demonstrate a high frequency of SRC-3 overexpression in NSCLC with a gender difference, suggesting that there is a specific role for SRC-3 in the pathogenesis of NSCLC. (J Histochem Cytochem 58:1121–1127, 2010)     

微生物发酵生产十一烷1，1 1二羧酸的研究

从热带假丝酵母(Candiada tropicalis)T25—14经过紫外线和亚硝酸的多次诱变,获得4株产十一烷l,11二羧酸(DC₁₃)较多的突变株,其中最优的NP-159株以20％(V／V)正十三烷(nC₁₃)为碳源摇瓶发酵4天,DC₁₃达80g／L左右。在16L罐上,以30％(V／V)nC₁₃发酵6天,DC₁₃高达139g／L,回收残烃后,对nC₁₃的转化率为80％以上。后处理收率为78．9％,DC₁₃的纯度为95．3％。     

Human kidney anion exchanger 1 interacts with adaptor-related protein complex 1 μ1A (AP-1 mu1A)

Kidney anion exchanger 1 (kAE1) mediates chloride (Cl⁻) and bicarbonate (HCO₃⁻) exchange at the basolateral membrane of kidney α-intercalated cells. Impaired trafficking of kAE1 leads to defect of the Cl⁻/HCO₃⁻ exchange at the basolateral membrane and failure of proton (H⁺) secretion at the apical membrane, causing a kidney disease - distal renal tubular acidosis (dRTA). To gain a better insight into kAE1 trafficking, we searched for proteins physically interacting with the C-terminal region of kAE1 (Ct-kAE1), which contains motifs crucial for intracellular trafficking, by a yeast two-hybrid (Y2H) system. An adaptor-related protein complex 1 μ1A (AP-1 mu1A) subunit was found to interact with Ct-kAE1. The interaction between either Ct-kAE1 or full-length kAE1 and AP-1 mu1A were confirmed in human embryonic kidney (HEK) 293T by co-immunoprecipitation, affinity co-purification, co-localization, yellow fluorescent protein (YFP)-based protein fragment complementation assay (PCA) and GST pull-down assay. The interacting site for AP-1 mu1A on Ct-kAE1 was found to be Y904DEV907, a subset of YXXØ motif. Interestingly, suppression of endogenous AP-1 mu1A in HEK 293T by small interfering RNA (siRNA) decreased membrane localization of kAE1 and increased its intracellular accumulation, suggesting for the first time that AP-1 mu1A is involved in the kAE1 trafficking of kidney α-intercalated cells.     

Tbf1 or not Tbf1?

In this issue of Molecular Cell, Hogues et al. (2008) demonstrate a wholesale shift in the key regulatory protein involved in ribosomal protein (RP) synthesis during the evolution of S. cerevisiae and, en passant, raise interesting questions about the relationship between RP genes and telomeres.     

问题解答1

问 :蛋白质、核酸都是通过缩聚反应形成的吗 ?答 :由于人们对教材内容机械引入或对教材语意曲解 ,因而众多的复习资料无论在介绍蛋白质、核酸的结构还是生命起源时都人为地强调氨基酸“缩合”形成蛋白质、核苷酸“聚合”形成核酸。“缩合”与“聚合”似乎成了风马牛不相及的两个概念 ,更谈不上去探索其有机联系了。缩合源于生物化学中蛋白质 (或肽 )的形成 ,它可以指两个或多个氨基酸形成肽时脱去一个或多个水分子的反应。正由于它脱去小分子物质 ,而有别于加成反应 ,同时它发生在有机的小分子之间 ,且反应结果并没有形成不饱合键而不同于消…     

Niemann–Pick C1 Like 1 (NPC1L1) an intestinal sterol transporter

Niemann–Pick C1 Like 1 (NPC1L1) has been identified and characterized as an essential protein in the intestinal cholesterol absorption process. NPC1L1 localizes to the brush border membrane of absorptive enterocytes in the small intestine. Intestinal expression of NPC1L1 is down regulated by diets containing high levels of cholesterol. While otherwise phenotypically normal, Npc1l1 null mice exhibit a significant reduction in the intestinal uptake and absorption of cholesterol and phytosterols. Characterization of the NPC1L1 pathway revealed that cholesterol absorption inhibitor ezetimibe specifically binds to an extracellular loop of NPC1L1 and inhibits its sterol transport function. Npc1l1 null mice are resistant to diet-induced hypercholesterolemia, and when crossed with apo E null mice, are completely resistant to the development of atherosclerosis. Intestinal gene expression studies in Npc1l1 null mice indicated that no exogenous cholesterol was entering enterocytes lacking NPC1L1, which resulted in an upregulation of intestinal and hepatic LDL receptor and cholesterol biosynthetic gene expression. Polymorphisms in the human NPC1L1 gene have been found to influence cholesterol absorption and plasma low density lipoprotein levels. Therefore, NPC1L1 is a critical intestinal sterol uptake transporter which influences whole body cholesterol homeostasis.     

细胞色素P450 1A1和1B1靶向抗肿瘤前药研究进展

细胞色素P450（CYP）能催化各种内源性及外源性化合物的代谢,与多种肿瘤发生有关。其中CYP1A1参与多种前致癌物和致突变物的代谢活化,CYP1B1被认为在许多人癌细胞中特异性表达,参与药物的氧化代谢和前药的活化。CYP1A1和181已成为靶向抗肿瘤前药研究的新靶点。相继有大量相关研究报道,本文就近年来文献报道的CYP1A1和1B1靶向抗肿瘤前药研究进展。     

CYP1B1基因与青光眼

遗传性青光眼包括两种主要的类型,原发性开角型青光眼(primary open angle glaucoma,POAG)和原发性先天型青光眼(primary congenital glaucoma,PCG).眼前节发育不良(anterior segment dysgenesis,ASD)是眼发育异常的遗传异质性病,与增长的眼内压和青光眼有关,包括Peter's异常、Rieger's异常、无虹膜和虹膜发育不全.CYPIB1基因是PCG的致病基因,也有少数报道是POAG的修饰基因,或是POAG和ASD的致病基因.本文就CYP1B1基因突变与遗传性青光眼和ASD发育不全的关系及其遗传特点作一综述.     

沉默DEPDC1抑制鼻咽癌细胞HNE-1和CNE-1侵袭迁移

DEPDC1(DEP domain containing 1)是一个新的肿瘤相关基因,在多种恶性肿瘤的发生发展进程中起着重要作用。我们前期工作中在鼻咽癌细胞内沉默了DEPDC1的表达,发现抑制细胞增殖并诱发细胞凋亡。本研究旨在探讨沉默DEPDC1表达后,对鼻咽癌细胞HNE-1和CNE-1侵袭迁移能力的影响及其分子机制。结果显示,siRNA介导DEPDC1表达沉默后,细胞侧向运动能力、侵袭及迁移能力显著降低。qRT-PCR及Western印迹检测发现DEPDC1沉默导致EMT上游关键转录因子Twist1及间质细胞标志分子Vimentin表达显著下调。这些研究表明,鼻咽癌细胞中DEPDC1通过调节Twist1等EMT关键分子的表达在细胞侵袭转移过程中起关键作用。推测DEPDC1在鼻咽癌中高表达可能对于促进其侵袭转移具有重要作用,进而促进肿瘤发生发展,但具体分子机制仍有待更深入研究。     

Mutators in SACCHAROMYCES CEREVISIAE: MUT1–1, MUT1–2 and MUT2–1

The purpose of this study was to characterize two mutator stocks of yeast which were induced and selected on the basis of high spontaneous reversion rates of the suppressible "ochre" nonsense allele lys1-1. In the mutator stock VA-3, a single mutation, designated mut1-1, is responsible for the increase in the reversion rate of the ochre alleles lys1-1 and arg4-17. In stock VA-105, there are two separate mutator mutations. Tetrad analysis data showed these two loci are loosely linked. Based on complementation data, one of these mutations is at the same locus as mut1-1 and designated mut1-2. The second mutator of stock VA-105 was designated mut2-1. All three mutators are recessive. Both mut1-1 and mut1-2 give a high mutation rate for ochre nonsense suppressor (SUP) loci, but not for the ochre nonsense alleles. On the contrary, the mutation rates of the ochre alleles are greatly reduced. With the mutant mut2-1 there were mutations at both the lys1-1 site and its suppressors; mut2-1 is as effective as mut1-2 but not as effective as mut1-1 in inducing reversions of a missense mutant, his1-7. Neither mut1-1, mut1-2 nor mut2-1 were effective in inducing reversions of a putative frameshift mutation, hom3-10, or in inducing forward mutations to canavanine resistance.