磷酸化Akt和PTEN在非小细胞肺癌组织中的表达及其相关性

目的:探讨磷酸化Akt(p-Akt)与PTEN表达在非小细胞肺癌(NSCLC)侵袭、转移中的作用及其相关关系。方法:应用免疫组织化学SP法检测20例正常肺组织和102例非小细胞肺癌癌组织中p-Akt和PTEN蛋白的表达。结果:正常肺组织p-Akt为阴性表达,而PTEN为阳性表达;非小细胞肺癌癌组织中p-Akt表达的阳性率为41.2%(42/102),PTEN失表达率为46.1%(47/102)。p-Akt阳性表达和PTEN的失表达与肿瘤组织分化程度、临床分期以及有无淋巴结和远处转移相关。p-Akt和PTEN表达呈显著负相关(Phi r=-0.425,P<0.001)。结论:p-Akt过表达伴随着PTEN表达缺失,两者与NSCLC侵袭、转移有关。     

Correlation between NDRG1 and PTEN expression in endometrial carcinoma

N-myc Downstream-Regulated Gene 1 (NDRG1) is known as a differentiation-related gene that plays important roles in cell differentiation, organ formation, and embryonic development. NDRG1 has recently been shown to be associated with carcinogenesis and tumor progression in a wide variety of tumors. Phosphatase and tensin homolog deleted from chromosome (PTEN), a phosphatase and tensin homolog located on chromosome 10, is shown to be a tumor suppressor and is often mutated or deleted in various tumor cells, particularly in endometrial carcinoma. Using an immunohistochemical approach, we investigated the expression of NDRG1 and PTEN in normal endometrium, atypical hyperplasia, and endometrial carcinoma. All tumor tissues harvested in this study were derived from endometrioid carcinoma Type I, that were estrogen-related. Our results demonstrate that the expression of NDRG1 was up-regulated in 5/40 (12.5%), 18/34 (52.94%), and 86/103 (83.5%) normal endometrium, atypical hyperplasia, and endometrial carcinoma cases, respectively ( P <  0.01), while in 6/40 (15%), 20/34 (58.82%), and 89/103 (86.41%) normal endometrium, atypical hyperplasia, and endometrial carcinoma cases, respectively. PTEN expression was significantly decreased ( P <  0.01). Statistical analyzes demonstrated a positive correlation between NDRG1 up-regulation and PTEN down-regulation ( P <  0.01). The expression of NDRG1 had no correlation with the differentiation degree of the tumor cells, lymph-node metastasis, and/or abdominal cavity implantation ( P  > 0.05). Our results indicated that development of endometrial carcinoma is associated with an overexpression of NDRG1 and the loss of PTEN expression. Identification of changes in the NDRG1 and PTEN expression may be a significant diagnostic tool for the early detection of endometrial carcinoma. ( Cancer Sci 2008; 99: 706–710)     

PTEN和K-ras与子宫内膜癌关系的研究进展

目的:总结近年来国内外关于PTEN、K-ras在子宫内膜癌中表达及相互关系的研究进展。方法:应用PubMed及CNKI全文数据库检索系统,以"子宫内膜癌、PTEN和K-ras"为关键词,检索1988-01-2011-06的相关文献,共检索到英文文献457篇,中文文献176篇。文献纳入标准:1)PTEN及K-ras的生物学特性及作用机制;2)PTEN、K-ras分别在子宫内膜癌中的表达;3)PTEN和K-ras在子宫内膜癌中的共同表达。根据纳入标准符合分析文献26篇。结果:在子宫内膜癌组织中存在PTEN的表达缺失,而且在子宫内膜癌中PTEN突变率(23.5%～55.0%)高。PTEN缺失或突变诱导了细胞持续增殖和恶性转化,促进肿瘤的形成。K-ras的突变往往发生于子宫内膜癌的早期,K-ras基因的表达与其组织学分级及临床分期有关,组织学分级越差、临床分期越晚,K-ras基因的阳性表达率越高。结论:PTEN和K-ras同属于子宫内膜癌的早期分子事件,在子宫内膜癌发生、发展过程中起着协同效应。     

子宫内膜癌中PTEN蛋白、P-AKT蛋白的表达及意义

目的:检测子宫内膜癌组织中PTEN蛋白及P-AKT蛋白表达并探讨其意义.方法:采用免疫组织化学法检测66例子宫内膜癌、28例正常子宫内膜组织中PTEN蛋白及P-AKT的表达.结果:子宫内膜癌组织中PTEN蛋白为缺失表达,高于正常子宫内膜组织(P＜0.05),而且PTEN表达在G1级肿瘤高于G2、G3级(P＜0.05),PTEN蛋白缺失率与肿瘤组织类型有关(P＜0.05),与肌层浸润、淋巴结转移及病理分期无明显关系(P＞0.05).子宫内膜癌组织中P-AKT蛋白表达为高表达,P-AKT的表达与肿瘤组织学分级、病理学分期、有无淋巴结转移以及肿瘤浸润子宫肌层深度显著相关(P＜0.05),其表达与组织学类型无关(P＞0.05).P-AKT与PTEN的表达呈明显负相关.结论:PTEN表达缺失与临床病理参数无关,蛋白表达缺失常发生细胞分化较差的子宫内膜癌.PTEN蛋白表达缺失与P-AKT表达水平有关.     

PTEN expression in endometrial biopsies as a marker of progression to endometrial carcinoma

Inactivation of PTEN tumor suppressor gene is common in endometrial carcinoma and its precursor, atypical endometrial hyperplasia (EH). We compared PTEN expression via immunohistochemistry in endometrial biopsies diagnosed as EH in 138 cases, who were diagnosed with EH and then endometrial carcinoma at least 1 year later (median, 6 years), and 241 individually matched controls, who were diagnosed with EH but did not progress to carcinoma during equivalent follow-up. We assessed PTEN status (normal versus null) in index biopsies containing EH to estimate the relative risk (RR) of developing endometrial carcinoma up to 25 years later. Analysis of 115 cases and 193 controls with satisfactory assays revealed PTEN-null glands in index biopsies of 44% of cases and 49% of controls [P = 0.85; RR, 1.51; 95% confidence interval (CI), 0.73-3.13]. For predicting progression to carcinoma, PTEN-null status had low sensitivity (44%; 95% CI, 45-54%) and specificity (51%; 95% CI, 44-58%). Among 105 cases with PTEN results for both index biopsy and carcinoma, 16% had a PTEN-null index biopsy, 23% had PTEN-null carcinoma, and 26% had both a PTEN-null index biopsy and carcinoma. Loss of PTEN expression in endometrial biopsies was neither associated with nor a sensitive and specific marker of subsequent progression to endometrial carcinoma.     

PTEN 在不同类型子宫内膜中的表达

目的：检测PTEN在不同类型子宫内膜组织中的表达，探讨其在内膜癌发生中的作用。方法：应用SP法检测88例子宫内膜组织中PTEN蛋白的表达，结合临床病理资料进行分析。结果：PTEN在正常内膜、单纯增生、复合增生、不典型增生及内膜癌中的表达率分别为：85％、77．7％、66．6％、90％和44．7％。按正常内膜到内膜癌的顺序与PTEN的表达强度进行相关分析，两者呈负相关（r=-0．446，P=0．000）；内膜癌组，PTEN表达率在Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别是48．1％、75％、16．6％、0％，在G1、G2、G3分别为63．6％、35．2％、40％，在肌层无侵袭、侵袭〈1／2和肌层〉1／2肌层分别是42．8％、41．6％、57．1％，PTEN表达与三者均无关；内膜癌中PTEN的表达与血CA125水平呈负相关（r=-0．327，P=0．04）。结论：PTEN蛋白的低表达与内膜癌发生发展相关，PTEN表达与内膜癌临床分期、病理分级及肌层浸润可能无关。     

子宫内膜癌组织中PTEN基因突变及蛋白表达的检测

背景与目的:肿瘤抑制基因———第10染色体同源丢失性磷酸酶-张力蛋白基因(phosphataseandtensinhomologdeletedonchromosometen,PTEN)被称为子宫内膜的看家基因。但有关PTEN基因在子宫内膜癌发生发展中的确切作用尚不清楚。本研究旨在检测子宫内膜癌组织中PTEN基因的突变及蛋白表达情况。方法:应用聚合酶链反应-单链构象多态性分析(polymerasechainreaction-singlestranconformationpolymorphism,PCR-SSCP)和DNA序列分析法,检测52例子宫内膜癌组织和10例正常子宫内膜组织中PTEN基因第5和第8外显子的突变;免疫组织化学法检测PTEN蛋白的表达,并结合临床病理特征进行分析。结果:子宫内膜癌组织的PTEN基因突变率和蛋白缺失率分别为25%和60%,高于正常子宫内膜组织(0%),差异有显著性(P<0.05)。病理学分级为G1、G2及肌层浸润深度<1/2的组织的PTEN基因突变率高于病理学分级为G3及肌层浸润深度≥1/2者,而病理学分级为G1、G2组织的PTEN蛋白表达缺失率低于病理学分级为G3者,差异有显著性(P<0.05)。PTEN基因突变率和蛋白表达缺失率在子宫内膜样腺癌和其它组织类型之间比较,差异有显著性(P<0.05),而在不同手术分期之间差异无显著性(P>0.05)。结论:PTEN基因突变和蛋白阳性表达常发生在病理学分级较低的子宫内膜癌病例     

甲状腺癌中PTEN蛋白表达与BRAFV600E突变的相关性研究

目的：探讨PTEN蛋白在甲状腺乳头状癌（PTC）中的表达情况,并进一步分析此蛋白的表达量与BRAFV600E基因突变的相关性及临床意义,初步揭示两者在PTC发生、发展中的致癌作用。方法：采用免疫组化EnVision两步法检测70例PTC 中PTEN 蛋白的表达水平;采用 PCR法及 DNA 测序法检测上述标本中BRAFV600E突变情况,分析PTEN蛋白表达与BRAFV600E突变的相关性及其与PTC临床病理特征的关系。结果：70例PTC中PTEN阴性率为78．6％（55／70）,与癌旁组织18．6％（13／70）比较,差异有统计学意义（P＜0．05）。PTEN表达下调与性别、肿瘤淋巴结转移、临床分期有关（P＜0．05）;与BRAFV600E突变、年龄、肿瘤直径无关（P＞0．05）。70例PTC中BRAFV600E突变率为60％,BRAFV600E突变与肿瘤淋巴结转移、临床分期密切相关（P＜0．05）;与患者年龄、性别、肿瘤大小无关（P＞0．05）。结论：PTEN蛋白表达与BRAFV600E突变无相关性。两者可能是PTC生物侵袭高的独立危险因素,可能作为评估PTC预后不良的不同肿瘤标记物。两者对甲状腺癌的临床个体化治疗及判定预后有指导意义。     

PTEN在肝癌中低表达的意义

目的探讨PTEN表达与肝细胞癌发生、发展的关系.方法检测PTEN在肝癌组织和肝癌细胞系中的表达情况,以观察该基因与肝癌病理分级、转移和预后的关系.结果肝癌中PTEN表达阴性率为30.16%（19/63）,显著高于正常肝组织0（0/8）和肝硬化组织7.15%（1/14）.随着恶性程度的增高,PTEN表达阴性率随之增加.PTEN表达阴性与是否转移及预后显著相关.PTEN在人肝癌细胞系HHCC中也不表达.结论抑癌基因PTEN低表达多见于肝细胞肝癌进展期,并与肝细胞肝癌分化程度、是否转移以及临床预后相关.     

子宫内膜癌组织中PTEN基因突变、PTEN蛋白及雌激素受体亚型的表达及意义

目的:检测子宫内膜癌组织中PTEN基因的突变、蛋白表达及雌激素受体亚型(ERα、ERβ)mRNA表达并探讨其意义。方法:采用聚合酶链反应-单链构象多态性分析(PCR-SSCP)检测36例子宫内膜癌、20例正常子宫内膜组织中PTEN基因第5和第8外显子的突变;免疫组织化学法检测PTEN蛋白的表达;逆转录-聚合酶链反应(RT-PCR)扩增ERα和ERβ片段检测其mRNA的相对表达水平。结果:子宫内膜癌组织中PTEN基因突变率和蛋白缺失率分别为30.6%和61.1%,高于正常子宫内膜组织(0)(P<0.05)。PTEN蛋白表达完全缺失在G2、G3级肿瘤高于G1级(P<0.05),PTEN基因突变率和蛋白缺失率均与肌层浸润、淋巴结转移及手术-病理分期无明显关系(P>0.05)。ERαmRNA、ERβmRNA在PTEN表达缺失的肿瘤中低于PTEN表达阳性者(P<0.05)。结论:PTEN基因突变与临床病理参数无关,蛋白表达缺失常发生细胞分化较差的子宫内膜癌。PTEN蛋白表达缺失与ERαmRNA、ERβmRNA表达水平有关。     

PTEN expression in tamoxifen-associated endometrial cancers

Tamoxifen is associated with increased rates of endometrial hyperplasia and adenocarcinoma. Our previous work suggested tamoxifen-associated endometrial cancers might be associated with p53 mutations. PTEN, a tumor suppressor gene, is altered in low-grade endometrial carcinoma. This study evaluates PTEN immunohistochemical (IHC) expression in tamoxifen-associated endometrial cancers. MATERIALS AND METHODS: Twenty-eight endometrial carcinoma specimens were examined from patients with a history of breast cancer. Patients who had taken Tamoxifen (15) were compared to non-users (13). IHC staining was performed for PTEN; overexpression was defined as greater than 70% positivity. RESULTS: The mean duration of tamoxifen use was 3.3 years (3-171 months). Four out of 15 (27%) tamoxifen users expressed PTEN compared with 2 out of 13 (15%) of non-users. CONCLUSION: In this study, it appears that tamoxifen-associated endometrial cancers are not significantly different from sporadic endometrial cancer with regards to PTEN IHC expression, although there is a trend towards retained PTEN expression.     

Expression and significance of PTEN in endometrial carcinoma

Loss of heterozygosity of chromosome10q hasbeen reported in approximately40%of endometrialcarcinomas.PTEN,a candidate tumor suppressor genelocated at chromosome10q23.3,was identified andfound to be deleted or mutated in several differenttypes of human tumors[1-5].PTEN is a phosphatasethat negatively regulates the phosphoinositol-3-kinase/Akt pathway and mediates cell-cycle arrestand apoptosis[6,.To evaluate the role of PTEN in7]endometrial carcinoma,we investigated the expressionof PTEN …     

Phosphorylated Akt overexpression and loss of PTEN expression in non-small cell lung cancer confers poor prognosis

Akt, a downstream mediator of phosphatidylinositol 3-kinase (PI3K), is a signal transduction protein that plays a central role in tumorigenesis. The tumor suppressor gene PTEN negatively regulates the PI3K/Akt signaling pathway. However, the roles of Akt and PTEN function in patients with non-small cell lung cancer (NSCLC) is not well established. To clarify roles of expression of phosphorylated Akt (p-Akt) and loss of PTEN expression in biological behavior and prognosis of NSCLC. Immunohistochemical staining was used to determine the expression of p-Akt and PTEN in 20 cases of normal lung tissues and 102 cases patients with NSCLC. All patients with NSCLC were followed from 3 to 60 months. The positive incidence of p-Akt expression and loss incidence of PTEN expression in NSCLC were 41.2% (42/102) and 46.1% (47/102), while negative of p-Akt expression (0%, 0/20) and positive of PTEN expression (100%, 20/20) in normal lung tissues. Overexpression of p-Akt and loss of PTEN expression were correlated to poor differentiation, lymph node involvement, distant metastasis and late stages. A significant negative correlation was observed between expression of p-Akt and PTEN (r = -0.425, P < 0.001). Patients with p-Akt positive expression (42/102) and loss of PTEN expression (47/102) showed significantly worse 5 years survival rate and median survival time than relevant those with p-Akt negative expression (14.29% versus 33.33%, 14 months versus 32 months, Log-rank test X(2) = 14.24, P < 0.001) and PTEN positive expression (10.64% versus 38.18%, 15 months versus 40 months, Log-rank test X(2) = 21.06, P < 0.001). A univariate analysis revealed that smoking, tumor size, lymph node involvement, distant metastasis, stage, p-Akt and loss of PTEN expression were significant correlative factors with prognosis. The result of multivariate Cox analysis showed that smoking, stage and loss of PTEN expression were independent prognosticators. p-Akt is overexpressed and accompanied by the loss of PTEN in clinical specimens of NSCLC. Both p-Akt and PTEN are concerned with invasion and metastasis of NSCLC. Loss of PTEN expression is an independent poor prognostic factor for patients with NSCLC.     

PTEN和CyclinE蛋白在子宫内膜癌组织中的表达

目的探讨子宫内膜良性、癌前病变和恶性病变中PTEN、CyclinE蛋白的表达及其意义.方法采用免疫组化S-P法检测正常子宫内膜、子宫内膜增生、非典型性增生和子宫内膜癌组织中PTEN和CyclinE蛋白.结果非典型性增生组和子宫内膜样癌组中PTEN和CyclinE蛋白阳性表达率分别为60.0%,50.0%和42.0%,62.2%.非典型性增生组中PTEN的阳性表达显著低于正常组和增生组(P<0.02),而CyclinE的阳性表达则显著高于正常组和增生组(P<0.03).PTEN和CyclinE蛋白在子宫内膜样癌组中的表达呈负相关(r=-0.4475,P<0.01).宫内膜样癌中PTEN蛋白阳性表达的缺失与组织学分级(P<0.02)及肌层浸润深度或伴有转移有关(P<0.04),与临床分期无关(P>0.05).CyclinE的阳性表达率则与组织学分级有关(P<0.05),与肌层浸润(P>0.05)和临床分期无关(P>0.05).结论 PTEN表达缺失和CyclinE的过度表达与子宫内膜样癌的发生发展密切相关,二者的联合检测可作为子宫内膜样癌早期诊断的生物学指标.     

PTEN蛋白表达与子宫内膜癌的相关性研究

目的:探讨子宫内膜癌中抑癌基因PTEN的表达,及其与子宫内膜癌临床病理特征及预后的关系.方法:采用免疫组化检测16例正常子宫内膜、32例子宫内膜癌组织中PTEN蛋白的表达,分析其与临床病理的相关性.结果:抑癌基因PTEN在子宫内膜癌组中蛋白阳性表达显著低于正常子宫内膜组(P<0.01).PTEN阳性表达的缺失与组织学分级与肌层浸润深度有关(P<0.05).结论:PTEN基因突变及蛋白表达缺失与子宫内膜癌的发生有关,与子宫内膜癌的分化程度、肌层浸润深度有相关性.     

胃癌组织Skp2表达的意义及其与P27、PTEN表达的关系

背景与目的:S期激酶相关蛋白2(S-phaseKinase-associatedProtein2,Skp2)促进泛素介导的细胞周期素依赖激酶抑制剂P27蛋白降解,是细胞G1-S期转化所必需。研究发现Skp2过表达参与细胞转化和肿瘤的形成。本研究旨在探讨人胃癌Skp2表达的意义及Skp2与P27和PTEN表达的关系。方法:采用免疫组化法检测胃癌组织及配对癌旁胃粘膜138例、配对淋巴结转移癌组织102例、非典型增生30例、肠上皮化生30例、慢性浅表性胃炎10例和正常胃粘膜5例Skp2表达及138例胃癌P27和PTEN的表达。结果:Skp2的标记率(%)在肠化(12.68±0.86)及癌旁胃粘膜(19.32±1.22)均明显高于慢性浅表性胃炎(0.53±0.13)及正常胃粘膜(0.47±0.19)(P<0.001),后两者无显著性差异(P﹥0.05);非典型增生(16.74±0.82)明显高于肠化(P<0.001);原发胃癌(31.34±2.17)明显高于非典型增生及癌旁胃粘膜(P<0.001);淋巴结转移胃癌组织(39.76±2.00)明显高于原发胃癌(P=0.037)。胃癌Skp2标记率与分化程度(rs=0.315,P=0.000)、脉管内瘤栓(rs=0.303,P=0.000)及淋巴结转移(rs=0.254,P=0.000)呈正相关。胃癌Skp2表达与靶蛋白P27表达(rs=-0.451,P=0.000)和肿瘤抑制蛋白PTEN(rs=-0.480,P=0.000)表达呈负相关;胃癌PTEN表达与P27表达呈正相关(rs=0.642,P=0.000)。结论:胃癌Skp2蛋白过表达与P27蛋白降解及PTEN蛋白低表达有关,提示Skp2蛋白过表达可能是胃癌发生和发展的一个重要原因。     

Akt activation in renal cell carcinoma: contribution of a decreased PTEN expression and the induction of apoptosis by an Akt inhibitor.

BACKGROUND: Akt has been implicated in the oncogenesis of human malignant tumors, because Akt regulates many key effector molecules involved in cell survival. PTEN (phosphatase and tensin homolog deleted on chromosome 10) negatively regulates Akt activation. MATERIALS AND METHODS: The expression of phosphorylated Akt (p-Akt), total Akt and PTEN was analyzed by Western blotting in 45 renal cell carcinoma (RCC) patients. The Bad and phosphorylated Bad (p-Bad) statuses were analyzed in 20 RCC patients. A phosphatidylinositol ether analog was used as an Akt inhibitor to treat four RCC cell lines, namely Caki-1, KU19-20, SW839 and Caki-2. RESULTS: The PTEN expression in RCC was observed to decrease and p-Akt expression to increase significantly in comparison with that in the corresponding normal kidney tissue. The PTEN expression inversely correlated with the p-Akt expression. These alterations were specific for clear cell type RCC, but not for papillary or chromophobe type RCC. Alterations in Bad phosphorylation were also specifically observed in clear cell type. The Akt inhibitor induced apoptosis in KU19-20 and Caki-2 cells with a high Akt activity. CONCLUSIONS: A decreased expression of PTEN may be an underlying mechanism for Akt activation. An Akt inhibitor may be a therapeutic option for a subset of RCC with an elevated Akt activity.     

PTEN在子宫内膜癌中的研究进展

PTEN基因是具有磷酸酶活性的抑癌基因,许多肿瘤中均存在PTEN突变,其中突变率以子宫内膜癌(EC)最高.近年EC发病率有上升趋势,迄今其发生发展的分子遗传学机制尚不清楚.现综述PTEN在EC中的作用机制、突变谱、临床病理学意义等进展.     

Correlation between receptor status and results of treatment in endometrial carcinoma

In the course of immunohistochemical assay of estrogen (ER), progesterone (PR) and oncoprotein HER-2/neu receptors, PR+ expression was identified in 52% of 50 patients with endometrial carcinoma. A direct correlation between ER and PR levels (i = 0.7) was established (ER+/PR(+)--26.0%; ER-/PR(-)--42.0%; ER-/PR(+)--26.0%; ER+/PR(-)--6.0%). In the ER+/PR+ and--ER-/PR+ groups, adjuvant therapy with progestins was carried out (3-year-survival--95.3% (p < 0.05)); recurrence rate--8.0%. Inverse correlations were characteristic of ER and HER-2/neu (i = -0.4) and PR and HER-2/neu (i = -0.114). Adjuvant polychemotherapy was administered in 12.2% of cases of HER-2/neu over-expression. That group revealed a drop in 3-year survival from 85.5 to 41.7% and relapse in half of the patients.     

Significance of PTEN alterations in endometrial carcinoma: a population-based study of mutations, promoter methylation and PTEN protein expression

Mutations in the PTEN gene are frequent in endometrial carcinoma. PTEN methylation is an alternative mechanism of gene inactivation. To elucidate different mechanisms of PTEN gene inactivation, we have studied a population-based series of endometrial carcinomas for PTEN mutations in relation to clinicopathologic characteristics, promoter methylation and protein expression. PTEN mutations were found in 54%, mainly in exons 5 and 8; with at least two different mutations in 21%. Presence of PTEN mutation was significantly correlated with young age, low FIGO-stage, endometrioid subtype, low grade, microsatellite instability and favourable prognosis. Previous studies of these tumours have observed PTEN methylation in 18% and low protein expression in 20%. Low expression of PTEN-antibody 6H2.1 was correlated with the presence of mutations in exon 8 among patients with 'two hits'; i.e. > or =2 mutations, or mutation(s) plus methylation (p=0.001). Number of PTEN hits was significantly associated with microsatellite instability, low hMLH1 expression and hMLH1 methylation. Thus, PTEN mutations are frequent in sporadic endometrial carcinoma and define a prognostically favourable subgroup, whereas the relationship with PTEN protein expression is complex. A pathway in endometrial carcinogenesis involving PTEN mutation and microsatellite instability is confirmed, and this study also indicates the importance of PTEN and hMLH1 methylation in this pathway.