FoxO3a与肿瘤的发生和发展

叉头转录因子O亚型(forkhead box O,FoxO)3a是FoxO家族一员,具有抑癌基因的作用,调控多种肿瘤的发生发展,包括乳腺癌、前列腺癌、白血病、胶质母细胞瘤等。FoxO3a作为磷脂酰肌醇3-激酶/蛋白激酶B(phosphatidylinositol 3-kinase/protein kinase B,PI3K/Akt)信号通路的重要靶分子,主要通过AKT磷酸化与去磷酸化起作用,调节其活性以及下游信号分子如细胞死亡调解因子、Fas配体和细胞周期蛋白依赖性激酶等转录作用,诱导肿瘤细胞凋亡。药物调控FoxO3a的活性和分布有望成为癌症治疗的新思路。     

Wnt信号通路成员APC蛋白和β—catenin与肿瘤的关系

APC蛋白和β—catenin是Wnt信号通路β—catenin降解复合体的重要组分，在Wnt信号通路异常导致甲状腺肿瘤的发生中，它们发挥重要的作用。     

Wnt信号通路成员APC蛋白和β-Catenin与肿瘤的关系

APC蛋白和β- catenin是 Wnt信号通路β- catenin降解复合体的重要组分 ,在 Wnt信号通路异常导致甲状腺肿瘤的发生中 ,它们发挥重要的作用     

Wnt信号通路与神经发生

W nt通路是细胞增殖分化的关键调控环节,在胚胎发育和肿瘤发生中起着重要作用。W nt途径参与了基因表达调节、细胞迁移粘附、细胞极化等过程,同时还与其它信号通路存在交叉协同。W nt/β-caten in通路在进化过程中高度保守,此通路的主要分子构成及相关调控机制已得到基本阐明。对神经系统而言,已有足够证据显示此通路参与了对神经前体细胞增殖,分化以及决定细胞命运的调控。近年更有研究显示,W nt/β-caten in途径对神经系统的发育包括皮层模式建立,突触形成等也是至关重要的。     

乳腺癌不同分子亚型中Wnt/β-catenin信号传导通路的异常表达

目的检测Wnt信号通路的关键组分β-catenin蛋白在管腔A、管腔B、HER-2过表达、基底细胞样及未分类型(基底细胞样及未分类型统称为三阴型)乳腺癌中的表达及细胞内定位,及其与乳腺癌临床病理参数的关系。方法采用免疫组化Eli Vison两步法检测58例乳腺癌中β-catenin蛋白表达及细胞内定位。结果 (1)管腔A、管腔B、HER-2过表达、基底细胞样及未分类型乳腺癌中β-catenin胞质异常表达阳性率分别为21.1%、50%、60%、100%及60%(三阴型84.6%),差异有显著性(P<0.01)。β-catenin高胞质表达与基底细胞样及三阴型乳腺癌相关(P<0.05)。(2)β-catenin胞质异常表达与组织学分级相关(P<0.01),与淋巴结转移、肿瘤大小、患者年龄无关;与E-cadherin膜表达缺失、Ki-67及CK5/6表达呈正相关(P<0.05),与ER及PR表达呈负相关(P<0.01)。结论乳腺癌中Wnt信号通路的异常与组织学分级、Ki-67及CK5/6表达呈正相关,与ER、PR表达呈负相关。基底细胞样及三阴型分子亚型有更高频率的Wnt信号异常。β-catenin有可能成为基底细胞样及三阴型乳腺癌的治疗靶点。     

骨转移瘤发病的细胞生物学机制与细胞分子靶向治疗

骨骼是实体肿瘤转移最常见的部位。骨转移瘤目前不可治愈,发病率高,可以导致一系列骨相关事件,显著降低患者的生活质量,加重患者家庭的经济负担。肿瘤细胞转移至骨骼的生物学机制正处于研究之中,这些机制包括成骨细胞"双重"调节与骨保护素-核因子-κB受体活化因子配体-核因子-κB受体活化因子系统、肿瘤细胞和骨骼微环境中细胞产生的各种细胞因子激活破骨细胞以及相关分子的作用,例如甲状旁腺激素相关蛋白(PTHr P)介导"恶性循环"。一些具有吸引力的分子或者通路已经成为治疗骨转移瘤的新潜在性靶点,例如核因子-κB受体活化因子配体(RANKL)、组织蛋白酶K、PTHr P以及Wnt信号通路等。本综述主要阐述正常骨骼生物学、骨转移瘤骨骼生物学机制以及细胞分子靶向治疗的临床进展。这些治疗制剂包括二磷酸盐、迪诺塞麦(RANKL抑制剂)和奥当卡替(组织蛋白酶K抑制剂)。更好地理解骨转移瘤发病的生物学机制和发展更有效的靶向制剂,将有希望延长患者的生存期以及提高患者的生活质量。     

孤立性纤维性肿瘤中β-catenin的表达及其临床意义

目的 探讨Wnt通路中核心蛋白β-catenin及其下游基因在孤立性纤维性肿瘤(solitary fibrous tumor,SFT)中的表达及意义.方法 运用原位杂交法和免疫组化SP法,检测β-catenin以及bcl-2、cyclin D1、c-myc在SFT肿瘤细胞中mRNA及蛋白的表达水平及定位.结果 22例SFT中,β-catenin原位杂交阳性表达者14例(63.64%),免疫组化阳性表达者16例(72.73%),两种检测结果呈正相关.22例SFT中,bcl-2、cyclin D1和c-myc的蛋白表达阳性率分别为:81.82%(18/22)、63.64%(14/22)、18.18%(4/22).免疫组化β-catenin阳性表达的16例中,强阳性染色率为43.75%(7/16),弱阳性染色率为56.25%(9/16).在良性组和潜在恶性组之间,β-catenin、bcl-2、cyclin D1、c-myc的阳性表达率的差异均无统计学意义.而β-catenin在两组中强阳性染色率分别为13.33%(2/15)和71.43%(5/7),两者差异具有统计学意义(P=0.01).结论 Wnt通路的激活存在于孤立性纤维性肿瘤的发生过程中,免疫组化法检测β-catenin蛋白强阳性染色对判断SFT的预后有一定临床意义.     

Wnt和Notch信号通路在大鼠创面愈合模型中的表达作用

目的观察Wnt和Notch信号通路在大鼠创面愈合模型中的表达及作用。方法取25只SD大鼠幼鼠,早期用溴脱氧尿苷（BrdU）标记表皮干细胞,注射BrdU 60 d后建立全层皮肤缺损创面模型。于大鼠致伤后0 d、7 d、14 d、21 d、30 d五个时间点分别各断颈处死5只取标本,利用免疫印迹、免疫组化和免疫荧光双标法观察创面愈合过程中Wnt1、β-catenin、c-Myc、Jagged1、Notch1、Hes1和Brdu的表达情况。结果免疫印迹结果显示Wnt和Notch信号通路成员在伤后表达上调,于伤后7 d达高峰,持续表达至伤后30 d。免疫组化结果显示,β-catenin开始在细胞膜低表达,伤后逐渐转变为表皮全层表达,且部分呈现异常核表达;伤后,Notch1在表皮全层表达逐渐上调,且在基底层表达上调显著。免疫荧光提示,BrdU/c-Myc和BrdU/Hes1双染阳性细胞率在伤后上升,于伤后7 d达高峰,持续表达至伤后30 d。结论 Wnt和Notch双信号通路可能通过调控表皮干细胞的增殖分化参与大鼠创面愈合过程。     

黏着斑激酶与肿瘤

黏着斑激酶是一种非受体酪氨酸激酶,通过多种信号途径在细胞周期调控、生长调节、黏附、细胞骨架组装、运动、生存等方面发挥重要作用。研究发现,黏着斑激酶在多种肿瘤中高表达,参与肿瘤的发生、发展、侵袭、转移等。黏着斑激酶已成为当前肿瘤研究热点,有可能成为肿瘤治疗的新靶点。     

Nemo样激酶在肿瘤研究中的进展

Nemo样激酶(Nemo-like kinase,NLK)是一种进化上保守的促分裂原活化蛋白激酶类似性激酶,属于脯氨酸调控的丝氨酸/苏氨酸蛋白激酶超家族成员,也是经典Wnt/β-catenin信号通路中的一个重要的调节分子.在Wnt信号通路中,NLK被认为是β-catenin/TCF/LEF的抑制因子,负性调控着Wnt/β-catenin信号通路.最近研究表明,在某些肿瘤的发生、发展过程中,NLK发挥着重要的作用,日益成为当前研究的热点之一.     

MMP7 is a target of the tumour-associated antigen EpCAM

Epithelial cell adhesion molecule (EpCAM) is a single-transmembrane protein, which is involved in numerous cellular processes including cell adhesion, proliferation, maintenance of stemness of embryonic cells and progenitors, migration and invasion. Activation of signal transduction by EpCAM is warranted by regulated intramembrane proteolysis and nuclear translocation of the intracellular domain EpICD. Here, we describe matrix metalloproteinase 7 (MMP7) as a target gene of EpCAM signalling viaEpICD nuclear translocation. EpCAM and MMP7 expression pattern and levels positively correlated in vitro and in vivo, and were strongly elevated in primary carcinomas of the head and neck area. Hence, MMP7 is a novel target of EpCAM signalling.     

人上皮细胞黏附分子融合蛋白真核表达载体的构建、表达及初步鉴定

目的 :构建pIg EpCAM及pEGFP EpCAM真核表达载体 ,并在COS7细胞中表达。方法 :用PCR扩增EpCAMcDNA ,酶切后分别与pIg及pEGFP两种载体连接 ,用脂质体法转染COS7细胞。用免疫沉淀法检测pIg EpCAM的表达产物 ;用荧光显微镜观察EpCAM GFP的表达。结果 :DNA序列测定的结果显示 ,pIg EpCAM及pEGFP EpCAM载体的构建正确。免疫沉淀的结果显示 ,转染pIg EpCAM的COS7细胞的培养上清中含有相对分子质量 (Mr)为 6 5 0 0 0的融合蛋白 ,该蛋白与抗人IgGFc段的mAb具有良好的免疫反应性。荧光显微镜观察可见 ,转染空载体pEGFP的COS7细胞中绿色荧光均匀地分布于胞质和胞核 ;而转染pEGFP EpCAM的COS7细胞中绿色荧光主要分布于细胞表面。结论 :成功地构建了两种EpCAM的真核表达载体 ,并在COS7细胞中表达 ,为EpCAM的功能研究创造了条件 ,并为制备抗EpCAM的mAb提供了免疫原     

Localization of CD226 in the mouse hippocampus and cerebellum during adulthood and postnatal development

CD226, a member of cell adhesion molecules, has been widely studied in the immune system; however, its expression in the CNS remains unknown. In our present study, we detected CD226 mRNA and protein in the mouse hippocampus and cerebellum by RT-PCR and Western blotting, respectively. Immunohistochemical studies found that CD226 is primarily located in the hilus of the dentate gyrus and stratum lucidum aligned along the pyramidal cells in the hippocampal CA3 area, the interspaces of granular cells and the somata of the Purkinje cells in the cerebellar cortex during adulthood. Double-staining results revealed that CD226 co-localized well with synaptic marker proteins including synaptophysin, syntaxin and PSD-95. During postnatal development, CD226 could not be detected at its adult locations until postnatal day 12; however, it was temporally expressed in the somata of neighboring or distant nuclei associated with its adult location. These results showed the diverse localization of CD226 in the mouse hippocampus and cerebellum for the first time and suggested its potential role in the CNS.     

Neural cell adhesion molecule expression in renal cell carcinomas: relation to metastatic behavior

Neural cell adhesion molecule (NCAM), a member of the immunoglobulin superfamily, is expressed by a subgroup of renal cell carcinomas (RCCs) and by a limited number of adult organs, including the central nervous system (CNS) and adrenal gland. Because the major function of NCAM is homophilic adhesion between homotypic and heterotypic cells, we hypothesized that NCAM-expressing RCCs should preferentially metastasize to the CNS and adrenal gland. We did a retrospective immunohistochemical analysis of NCAM expression both in 338 primary renal tumors, including 249 conventional RCCs and 31 metastases of conventional RCCs. In primary renal tumors, NCAM was expressed by only 38 (15.2%) conventional RCCs and by no other histological subtypes of renal tumor. This expression correlated with a higher risk of adrenal and CNS metastases (P <0.001). NCAM expression also correlated with tumor size (P <0.001), renal vein involvement (P = 0.02), perirenal invasion (P = 0.02), and Fuhrman grading (P < 0.001). Finally, patients with NCAM-expressing RCCs had a lower survival rate (P = 0.006), especially in the first 2 years after surgery. NCAM expression is of interest both for evaluating the prognosis of patients with conventional RCCs and for determining a subgroup of patients at high risk for adrenal and CNS metastases.     

Media conditioned by retinal pigment epithelial cells suppress the canonical Wnt pathway

Retinal pigment epithelial (RPE) cells play critical roles in the maintenance of visual function, partly by secreting various biologically active factors that modulate the intraocular environment. Recent studies suggest involvement of Wnt proteins secreted by RPE cells in the pathogenesis of photoreceptor degeneration. In the present study, we examined, via the luciferase assay, the effect of media conditioned by RPE cells (RPE-CM) on activity of the canonical Wnt pathway in vitro. We isolated primary RPE cells from Long-Evans rats at P6-P9. In culture, these cells formed a monolayer with polygonal cell morphology and demonstrated repigmentation at confluency and immunoreactivity for ZO-1, a marker for tight junctions. To evaluate the effect of RPE-CM on the canonical Wnt pathway, we replaced the culture media of COS-7 cells transfected with (Tcf)(7)LUC, a multimeric Tcf-responsive element luciferase reporter construct, with RPE-CM and measured luciferase activity with or without Wnt3a or SB216763, a specific GSK3 inhibitor. RPE-CM did not enhance basal or Wnt3a-induced (Tcf)(7)LUC activity; instead, this activity decreased by 60%. RPE-CM also reduced SB216763-induced (Tcf)(7)LUC activity by 65%, which suggests that the inhibitory effect of RPE-CM is probably due to intracellular crosstalk rather than extracellular antagonism. RPE cells may thus be able to modulate the intraocular environment by regulating the canonical Wnt pathway.     

Wnt 信号通路和微生物在结直肠癌中的作用及意义

结直肠癌是临床上常见的恶性肿瘤之一,发病率在所有恶性肿瘤中排第3位,死亡率排第4位,对人类的健康造成了极大的威胁。近年来,在中国结直肠癌的发病率和死亡率均呈上升趋势,成为威胁人民健康的主要恶性肿瘤之一。结直肠癌发生和发展的机制非常复杂,涉及到的因素多种多样。例如,饮食、遗传、身体活动水平、环境等。目前具体致病机制还不十分清楚,这为结直肠癌的预防及治疗带来了极大的困难。随着分子生物学和分子遗传学的发展,已经明确 Wnt／β-catenin 信号通路在结直肠癌发生和发展中的重要作用。此外,越来越多的证据表明结直肠癌患者的肠道微生物群落与正常人存在明显不同,暗示了肠道微生物群与结直肠癌的关系。本文以 Wnt 信号通路和微生物为主线,总结它们之间的相互作用及在结直肠癌发生、发展和治疗中的作用。     

ORP-150基因沉默对SKOV-3细胞增殖、迁移及侵袭的影响

目的:探讨沉默ORP-150基因对体外培养卵巢癌细胞SKOV-3的增殖、转移及侵袭的影响并初步探讨其可能作用机制.方法:运用慢病毒包装shRNA方法沉默SKOV-3细胞的ORP-150基因;研究分为3组:实验组(ORP-150 shRNA)、阴性对照组(NC shRNA)和空白对照组(CON);采用qRT-PCR和Western印迹法检测基因敲减效率,CCK8法、克隆形成试验检测ORP-150沉默对细胞增殖能力的影响,划痕试验、Transwell试验检测SKOV-3细胞侵袭迁移能力的变化,流式细胞仪检测细胞的凋亡情况,Western印迹法探讨ORP-150基因敲减后影响细胞表型改变的作用机制.结果:沉默ORP-150基因可以抑制卵巢癌细胞的增殖能力、克隆形成能力以及跨膜转移扩散能力(P<0.05),但对细胞的侵袭能力无明显影响(P>0.05);敲减ORP-150基因后卵巢癌细胞凋亡明显增加(P<0.05);敲减ORP-150基因后的卵巢癌细胞可能通过Wnt信号通路及Caspase级联反应影响细胞的修复,最终抑制细胞增殖,促进凋亡发生.结论:沉默ORP-150基因可以抑制卵巢癌细胞SKOV-3的增殖和转移,同时促进凋亡发生.这种细胞表型的改变可能是通过下调Wnt信号通路中β-catenin,同时的表达,以及抑制Caspase级联反应从而下调c-myc,cyclin D1和caspase-3蛋白的表达来实现,ORP-150基因沉默可能是卵巢癌治疗的新靶点.     

Trophoblasts and soluble adhesion molecules in peripheral blood of women with pregnancy-induced hypertension

PROBLEM: The current hypothesis on the pathogenesis of pregnancy-induced hypertension (PIH) considers it as an endothelial disorder that is first local but with the potential of becoming general. The aim of the work was to investigate the relation of the number of trophoblast cells in maternal peripheral blood against the serum levels of soluble vascular and intercellular cell adhesion molecule (sVCAM-1 and sICAM-1) in PIH. METHOD OF STUDY: Women with PIH were at 28th to 40th week of gestation. Control group were normotensive (NT) pregnant women at 28th to 41st week of gestation. Flow cytometry was used to assess the relative number of the trophoblasts in the peripheral blood. Trophoblasts were labeled with monoclonal anti-human trophoblast protein antibody MCA 277. The presence of sVCAM-1 and sICAM-1 was determined using the enzyme-linked immunosorbent assay method. RESULTS: Women with PIH had significantly higher trophoblasts number than NT women (median 19.0, range 5.0-57.0/400 microL versus median 7.0, range 0.0-18.0/400 microL; P = 0.000011) as well as plasma level of sVCAM-1 when compared with NT women (median 730.0, range 325.0-1525.0 ng/mL versus median 493, range 310-1075 ng/mL; P = 0.02). ICAM-1 level in the PIH group was slightly elevated (median 280.0, range 174.0-524.0 ng/mL) when compared with NT women (median 260.0, range 190.0-464.0 ng/mL, P = 0.322). Eight of 21 women with PIH had proteinuria but no correlation was found between this symptom and the laboratory findings. CONCLUSION: The increased number of trophoblast cells in maternal peripheral blood and higher levels of sVCAM-1 correlate with the presence of PIH. The differences of sVCAM levels were significantly higher than those observed for sICAM. The results indicate an association between circulating trophoblasts and vascular endothelium activation, during PIH.