PTEN蛋白表达与前列腺癌病理分期的关系

目的:探讨PTEN蛋白在前列腺癌组织中的表达及其临床意义。方法:应用免疫组织化学S-P方法,检测前列腺癌及良性前列腺增生组织中PTEN蛋白的表达。结果:PTEN蛋白表达阳性随肿瘤细胞病理分级、临床分期的增高,PTEN蛋白阳性表达率降低。结论:PTEN蛋白异常表达在前列腺癌的进展中有重要作用,检测PTEN蛋白的表达有助于判断病情及预后。     

抑癌基因PTEN在胰腺癌组织中的表达及其意义

目的研究胰腺癌组织中PTEN蛋白及PTEN mRNA的表达及其临床病理意义.方法常规石蜡包埋切片SABC免疫组化法和原位杂交技术检测26例胰腺癌、12例癌旁组织及8例正常胰腺组织中PTEN蛋白和PTEN mRNA表达情况,同时结合病人的临床病理资料进行分析.结果 26例胰腺癌、12例癌旁组织及8例正常胰腺组织中,正常胰腺组织及癌旁组织PTEN蛋白阳性16例(75%),阳性物质位于胰腺腺细胞及胰岛细胞的胞质中,胰腺癌PTEN蛋白阳性10例,PTEN蛋白表达于癌细胞胞质,阳性率(38.4%)与正常组织存在显著差异(P<0.01).淋巴结未转移病例PTEN阳性率与淋巴结转移病例的阳性表达率无显著差异(P>0.05).PTEN mRNA表达结果与PTEN蛋白基本一致,胰腺癌PTEN mRNA阳性12例,阳性率(46.2%).结论 PTEN表达与胰腺癌临床病理特征和生物学行为存在密切关系.可能与胰腺癌的发生、发展及预后有关.     

大肠肿瘤中PTEN和TGF-β1表达及意义

目的 检测大肠癌及大肠腺瘤中PTEN和TGF-β1蛋白的表达,了解大肠癌临床病理的相关因素.方法 采用SP免疫组化法,检测PTEN和TGF-β1蛋白在大肠组织中的表达及意义.结果 PTEN在正常黏膜、大肠腺瘤、大肠癌组织中的阳性表达率分别为100%、70%和51.61%;而癌旁组织的阳性表达率60.87%,与癌组织相似,两者有明显的同步表达性.大肠癌中PTEN蛋白的阳性表达率明显低于非癌组(P< 0.05).TGF-β1在正常黏膜、大肠腺瘤及大肠癌中的阳性表达率分别为0%、40%、83.87%,癌旁组织为67.39%.正常黏膜组织TGF-β1的表达低于癌旁组织、大肠腺瘤和大肠癌(P< 0.05).PTEN表达随肿瘤分化程度的降低、临床分期提高而降低(P< 0.05),TGF-β1的表达与肿瘤分化程度、临床分期有关(P< 0.05);PTEN与TGF-β1的表达呈负相关.结论 PTEN表达降低和TGF-β1表达升高可能与大肠癌的发生发展密切相关,且可能与大肠癌生物学行为及预后有关.     

MMP-9和PTEN在胶质瘤中的表达及相关性分析

目的：检测脑胶质瘤组织中MMP-9和PTEN表达情况并探讨其意义。方法：采用免疫组织化学S-P法检测50例脑胶质瘤、10例正常脑组织中两者的表达。结果：脑胶质瘤组织中MMP一9和PTEN表达定位于细胞浆,其阳性表达率分别为74．00％（37／50）和60．00％（30／60）与正常脑组织0、100％有差异（P〈0．05）。两者的表达与胶质瘤患者的年龄、性别无明显相关性（P〉O．05）,但高级别组与低级别组之间表达有差异,具有统计学意义（P〈0．05）;在脑胶质瘤组织中MMP-9蛋白的阳性表达与PTEN蛋白的阳性表达有相关性,二者呈负相关（P〈0．05）。结论：MMP．9蛋白在胶质瘤组织中的表达明显高于正常脑组织,并且高级别胶质瘤组的表达明显高于低级别胶质瘤组中的表达,提示MMP-9可能与胶质瘤的浸润、发展、转移有关,可作为一个预测胶质瘤侵袭转移能力的肿瘤标志物。PTEN蛋白在正常脑组织中的表达明显高于胶质瘤,且高级别组表达明显高于低级别组,提示PTEN基因突变或缺失在胶质瘤的发生发展中起重要作用,且与肿瘤恶性分化程度密切相关,表明PTEN的失活预示着一个特殊的进展性的临床行为,在胶质瘤恶性进展中属于较晚发生的分子事件。     

前列腺癌组织及PC-3细胞中STAT3及磷酸化STAT3的表达

目的　研究前列腺癌组织及前列腺癌细胞株PC- 3 中STAT3 蛋白及磷酸化STAT3 蛋白的表达。方法　常规石蜡包埋切片SABC免疫组化法检测45例前列腺癌组织、20例前列腺增生组织中STAT3 及磷酸化STAT3 表达, 细胞免疫化学法检测前列腺癌细胞株PC 3细胞STAT3及磷酸化STAT3表达。结果　STAT3在前列腺癌及前列腺增生组织表达阳性率分别为77. 8%和50. 0%, 两者间具有显著差异; 磷酸化STAT3在前列腺癌及前列腺增生组织表达阳性率分别为68. 9%和35. 0%, 两者间具显著差异(P<0 .05); PC- 3细胞中STAT3及磷酸化STAT3表达阳性。结论　STAT3蛋白在前列腺癌中高表达且持续激活, 可能与前列腺癌的发生具有密切联系。     

微小RNA-21与PTEN在上皮性卵巢癌组织中的表达及临床意义

目的:检测微小RNA-21(miR-21)和抑癌基因PTEN在上皮性卵巢癌组织中的表达,探讨二者的相关性及其与临床病理特征间的关系.方法:采用茎环实时荧光逆转录聚合酶链反应(Real-time RT-PCR)检测48例上皮性卵巢癌组织、24例良性上皮性卵巢肿瘤及15例正常卵巢组织标本中miR-21表达.采用链霉菌抗生物素蛋白一过氧化酶(SP)免疫组化方法检测上述组织中PTEN蛋白表达,分析mir-21表达和PTEN表达的相关性及其与临床病理特征的关系.结果:茎环Real-time RT-PCR检测miR-21表达的敏感性和特异性良好;miR-21在卵巢癌组织中的相对表达量(4.849±1.813)显著高于良性卵巢肿瘤(1.133±0.291)及正常卵巢组织(P<0.01),PTEN在卵巢癌组织中阳性表达率为(41.66%),明显低于卵巢良性肿瘤(83.33%)及正常卵巢(100%).卵巢癌组织中miR-21表达量与PTEN阳性表达率存在显著负相关(r=-0.447,P<0.01).miR-21及PTEN表达随卵巢癌的临床分期和组织分级的进展分别呈上升及下降趋势,而且二者表达均与淋巴结转移相关(P均<0.01),而与组织病理类型无关.结论:miR-21在上皮性卵巢癌组织中的表达升高,可能通过负性调节PTEN表达在卵巢癌的发生发展中发挥致癌基因的作用,并且与卵巢癌的演进及不良预后密切相关.     

子宫内膜癌组织中PTEN和MTA1蛋白的表达及其相关性

目的：探讨子宫内膜癌组织中PTEN和MTA1表达及其与子宫内膜癌生物学行为之间的关系。方法：采用免疫组化SP法检测130例子宫内膜癌和40例正常宫内膜组织中PTEN和MTAl1的表达水平,并分析两者在子宫内膜癌中的相关性。结果：子宫内膜癌组织中PTEN、MTA1阳性表达均显著高于正常子宫内膜组织（P〈0．01）;PTEN与MTAI在子宫内膜癌组织中的表达呈负相关（r=0．35,P〈0．05）。结论：PTEN和MTA1表达与子宫内膜癌的发生、发展及生物行为密切相关,且两者表达存在负相关性。     

PTEN、HPV16/18-E6蛋白和雌激素受体在宫颈腺癌中的表达及其临床意义

目的：探讨宫颈腺癌组织中抑癌蛋白PTEN、人乳头瘤病毒（HPV）16/18-E6蛋白和雌激素受体（ER）的表达及其临床意义。方法：采用免疫组织化学S-P法对65例宫颈腺癌组织进行PTEN、HPV16/18-E6蛋白和ER检测,对30例慢性宫颈炎组织中HPV16/18-E6蛋白和ER的表达进行检测。结果：宫颈腺癌组织细胞核中PTEN的表达显著低于癌旁宫颈腺上皮组织（P〈0.01）,96%的宫颈腺癌细胞核呈低表达,而仅35%的癌旁宫颈腺上皮呈低表达（P〈0.01）;HPV16/18-E6蛋白和ER在宫颈腺癌中的阳性表达率分别为32.1%与49.4%,均显著高于慢性宫颈炎组织（P〈0.01）;HPV16/18-E6蛋白和ER的表达与宫颈腺癌的病理学分级、临床分期无关,在宫颈腺癌中的表达呈正相关。结论：PTEN在宫颈腺癌的发生中起一定的作用,其抑癌作用环节可能在细胞核水平;部分宫颈腺癌的发病可能与HPV16/18-E6蛋白过度表达有关;部分宫颈腺癌可能属于激素依赖性,雌激素可能有协同人乳头瘤病毒致癌的作用。     

非小细胞肺癌组织中PTEN表达的研究

目的探讨非小细胞肺癌（NSCLC）组织中PTEN的表达及临床意义。方法应用免疫组织化学和逆转录-聚合酶链反应（RT-PCR）方法检测了40例非小细胞肺癌及癌旁组织中PTEN和PTENmRNA的表达,结合临床病理资料,比较PTEN基因突变和mRNA表达与非小细胞肺癌临床病理特征的关系。结果PTEN在40例非小细胞肺癌组织中呈低表达,在癌旁组织中PTEN呈高表达。PTENmRNA在40例非小细胞肺癌组织中无表达29例,阳性表达11例,癌旁组织中PTENmRNA无表达的为8例,阳性表达为32例。癌组织阳性表达率显著低于癌周组织（P〈0.01）。结论非小细胞肺癌组织中存在较高比例的PTENmRNA表达缺失,表明PTEN基因转录水平异常在非小细胞肺癌的发生、发展中起了重要的作用。     

miR-9靶向调控PTEN在HPV16+及HPV18+宫颈癌细胞凋亡中的作用

研究微小RNA-9(microRNA-9,miR-9)靶向调控人第10号染色体缺失的磷酸酶及张力蛋白同源蛋白（Recombinantphosphataseandtensinhomolog,PTEN）在人乳头瘤病毒（Humanpapillomavirus,HPV）16+及HPV18+宫颈癌细胞凋亡中的作用。收集宫颈癌组织及正常宫颈组织，培养HPV16+SiHa细胞、HPV18+HeLa细胞、HPV阴性C33A细胞及正常宫颈上皮H8细胞，检测miR-9、PTEN的表达水平。SiHa细胞和HeLa细胞进行分组转染后检测增殖抑制率、凋亡率、PTEN及miR-9表达水平。结果显示高危型HPV阳性及阴性的宫颈癌组织中miR-9的表达水平高于正常宫颈组织、PTEN的表达水平低于正常宫颈组织（P<0.05）且高危型HPV阳性宫颈癌组织中miR-9、PTEN表达的变化更显著；SiHa细胞、HeLa细胞中miR-9的表达水平高于C33A细胞和H8细胞、PTEN的表达水平低于C33A细胞和H8细胞（P<0.05）；敲低miR-9表达后，SiHa细胞、HeLa细胞的PTEN表达水平、增殖抑制率、凋...     

Downregulation of PTEN/MMAC/TEP1 expression in human prostate cancer cell line DU145 by growth stimuli

Genetic alterations and/or deletion of the tumor suppressor gene PTEN/MMAC/TEP1 occur in many types of human cancer including prostate cancer. We describe the production of monoclonal antibody against recombinant human PTEN and the study of PTEN gene and protein expression in three commercially available human prostate cancer cell lines, PC-3, LNCaP, and DU 145. Northern blotting analyses showed that LNCaP and DU145 but not PC-3 cells expressed PTEN mRNA. However, Western blotting analyses using a monoclonal antibody against PTEN demonstrated the expression of PTEN protein in DU145 but not LNCaP cells. In DU145 cells, PTEN expression at both the mRNA and protein levels inversely correlated with serum concentrations and levels of PKB/Akt phosphorylation. In addition, the basal activity of PKB/Akt as indicated by level of phosphorylation was higher in prostate cancer cells which do not express PTEN than that in the cells expressing wild type PTEN. Thus, PTEN may play a critical role in regulating cellular signaling in prostate cancer cells.     

腮腺腺样囊性癌中PTEN、MDM2表达

目的:研究腮腺腺样囊性癌组织中抑癌基因PTEN、癌基因MDM2蛋白表达,探讨PTEN、MDM2在腮腺腺样囊性癌中两者之间的相关性,为将来临床应用提供参考。方法:选取腮腺腺样囊性癌手术存档石蜡标本30例,另取10例腮腺腺样囊性癌癌旁正常组织石蜡标本作为对照组,采用免疫组化SP法检验PTEN、MDM2表达情况。结果:腮腺腺样囊性癌和癌旁正常组织中PTEN蛋白的阳性率分别为20%(6/30)和70%(7/10),二者存在显著性差异(P0.05)。MDM2蛋白在两种组织中阳性率分别为66%(20/30)和20%(2/10)(P0.05),二者存在显著性差异(P0.05)(r=-0.657),在腮腺腺样囊性癌中PTEN、MDM2的表达负相关。结论:PTEN、MDM2蛋白异常表达在腮腺腺样囊性癌的发生发展中起重要作用。     

Regulation of the Tumor Suppressor PTEN through Exosomes: A Diagnostic Potential for Prostate Cancer

PTEN is a potent tumor-suppressor protein. Aggressive and metastatic prostate cancer (PC) is associated with a reduction or loss of PTEN expression. PTEN reduction often occurs without gene mutations, and its downregulation is not fully understood. Herein, we show that PTEN is incorporated in the cargo of exosomes derived from cancer cells. PTEN is not detected in exosomes derived from normal, noncancerous cells. We found that PTEN can be transferred to other cells through exosomes. In cells that have a reduction or complete loss of PTEN expression, the transferred PTEN is competent to confer tumor-suppression activity to acceptor cells. In PC patients, we show that PTEN is incorporated in the cargo of exosomes that circulate in their blood. Interestingly, normal subjects have no PTEN expression in their blood exosomes. Further, we found that the prostate-specific antigen (PSA) is incorporated in PC patients’ and normal subjects’ blood exosomes. These data suggest that exosomal PTEN can compensate for PTEN loss in PTEN deficient cells, and may have diagnostic value for prostate cancer.     

子宫内膜癌中PTEN与PI3K-Akt通路的表达及意义

目的：研究PTEN与P1K3-Akt通路在子宫内膜癌中的表达及临床意义。方法：采用免疫组化技术检测正常子宫内膜组织（24例）、子宫内膜样腺癌组织（55例）及子宫内膜浆液性癌组织（26例）中PTEN、P13Kp110α及P—AKTSer473的表达情况,分析其表达与组织病理参数的关系。结果：免疫组化结果显示：子宫内膜癌的PTEN表达缺失率,P13Kp110α及p-AKTser473表达阳性率均高于正常子宫内膜组织,且正常子宫内膜组织与子宫内膜样腺癌组织比较有统计学意义（P〈0．05）;随着肌层浸润深度增加,PTEN表达缺失率增加（P〈0．05）。结论：PTEN的表达缺失及P13Kp110α与P-AKTSer473的表达可能与子宫内膜癌的发生发展有关,尤其是在子宫内膜样腺癌的发生发展机制中占重要地位。     

Roles of the RAF/MEK/ERK and PI3K/PTEN/AKT pathways in malignant transformation and drug resistance

The Ras/Raf/MEK/ERK and PI3K/PTEN/AKT signaling cascades play critical roles in the transmission of signals from growth factor receptors to regulate gene expression and prevent apoptosis. Components of these pathways are mutated or aberrantly expressed in human cancer (e.g., Ras, B-Raf, PI3K, PTEN, Akt). Also, mutations occur at genes encoding upstream receptors (e.g., EGFR and Flt-3) and chimeric chromosomal translocations (e.g., BCR-ABL) which transmit their signals through these cascades. These pathways interact with each other to regulate growth and in some cases tumorigenesis. For example, in some cells, PTEN mutation may contribute to suppression of the Raf/MEK/ERK cascade due to the ability of elevated activated Akt levels to phosphorylate and inactivate Raf-1. We have investigated the genetic structures and functional roles of these two signaling pathways in the malignant transformation and drug resistance of hematopoietic, breast and prostate cancer cells. Although both of these pathways are commonly thought to have anti-apoptotic and drug resistance effects on cells, they display different cell-lineage-specific effects. Induced Raf expression can abrogate the cytokine dependence of certain hematopoietic cell lines (FDC-P1 and TF-1), a trait associated with tumorigenesis. In contrast, expression of activated PI3K or Akt does not abrogate the cytokine dependence of these hematopoietic cell lines, but does have positive effects on cell survival. However, activated PI3K and Akt can synergize with activated Raf to abrogate the cytokine dependence of another hematopoietic cell line (FL5.12) which is not transformed by activated Raf expression by itself. Activated Raf and Akt also confer a drug-resistant phenotype to these cells. Raf is more associated with proliferation and the prevention of apoptosis while Akt is more associated with the long-term clonogenicity. In breast cancer cells, activated Raf conferred resistance to the chemotherapeutic drugs doxorubicin and paclitaxel. Raf induced the expression of the drug pump Mdr-1 (a.k.a., Pgp) and the Bcl-2 anti-apoptotic protein. Raf did not appear to induce drug resistance by altering p53/p21^Cip−1 expression, whose expression is often linked to regulation of cell cycle progression and drug resistance. Deregulation of the PI3K/PTEN/Akt pathway was associated with resistance to doxorubicin and 4-hydroxyl tamoxifen, a chemotherapeutic drug and estrogen receptor antagonist used in breast cancer therapy. In contrast to the drug-resistant breast cancer cells obtained after overexpression of activated Raf, cells expressing activated Akt displayed altered (decreased) levels of p53/p21^Cip−1. Deregulated expression of the central phosphatase in the PI3K/PTEN/Akt pathway led to breast cancer drug resistance. Introduction of mutated forms of PTEN, which lacked lipid phosphatase activity, increased the resistance of the MCF-7 cells to doxorubicin, suggesting that these lipid phosphatase deficient PTEN mutants acted as dominant negative mutants to suppress wild-type PTEN activity. Finally, the PI3K/PTEN/Akt pathway appears to be more prominently involved in prostate cancer drug resistance than the Raf/MEK/ERK pathway. Some advanced prostate cancer cells express elevated levels of activated Akt which may suppress Raf activation. Introduction of activated forms of Akt increased the drug resistance of advanced prostate cancer cells. In contrast, introduction of activated forms of Raf did not increase the drug resistance of the prostate cancer cells. In contrast to the results observed in hematopoietic cells, Raf may normally promote differentiation in prostate cells which is suppressed in advanced prostate cancer due to increased expression of activated Akt arising from PTEN mutation. Thus in advanced prostate cancer it may be advantageous to induce Raf expression to promote differentiation, while in hematopoietic cancers it may be beneficial to inhibit Raf/MEK/ERK-induced proliferation. These signaling and anti-apoptotic pathways can have different effects on growth, prevention of apoptosis and induction of drug resistance in cells of various lineages which may be due to the expression of lineage-specific factors.