PTEN expression is associated with prognosis for patients with advanced endometrial carcinoma undergoing postoperative chemotherapy

The prognostic significance of PTEN expression in endometrial carcinoma has not been clear. We conducted the present study to clarify the relationship between PTEN expression and prognosis in advanced endometrial carcinoma. Of 784 patients with endometrial carcinoma who underwent primary treatment between 1985 and 2000 at 5 institutions, 98 pure endometrioid carcinomas with retroperitoneal lymph node metastasis were provided for our study. PTEN expression was determined by immunohistochemic staining. Negative or mixed PTEN staining was observed in 64 (65.3%) patients. The survival rate for PTEN-positive patients was significantly higher than that for PTEN-negative or -mixed patients. PTEN-staining status was not associated with patient age, International Federation of Gynecology and Obstetrics (FIGO) stage, myometrial invasion or histologic grade. Of the 98 patients, 87 received radiation therapy (n = 25) or chemotherapy (n = 62) after surgery. PTEN expression did not relate to survival for patients receiving radiation therapy. In contrast, the survival rate for PTEN-positive cases was significantly higher than that for PTEN-negative or -mixed cases when patients underwent chemotherapy (62.4% vs. 11.8%). Subsequent multivariate analysis revealed that PTEN staining was an independent prognostic factor for patients undergoing chemotherapy. PTEN-positive staining was a significant prognostic indicator of favorable survival for patients with advanced endometrial carcinoma who underwent postoperative chemotherapy.     

PTEN methylation is associated with advanced stage and microsatellite instability in endometrial carcinoma

Loss of heterozygosity and mutations in the PTEN (MMAC1) tumor suppressor gene are frequent in endometrial carcinoma. Promoter hypermethylation has recently been identified as an alternative mechanism of tumor suppressor gene inactivation in cancer, but its importance in the PTEN gene in endometrial carcinoma is unknown. The purpose of our study was to assess the frequency of promoter methylation of the PTEN gene and to determine its correlation with clinicopathologic variables in a prospective and population-based series of endometrial carcinomas with complete follow-up. Presence of PTEN promoter methylation was seen in 26 of 138 patients (19%). Methylation was significantly associated with metastatic disease (p = 0.01) and a microsatellite unstable phenotype (p = 0.006). In conclusion, we find that PTEN promoter methylation is relatively frequent in endometrial carcinoma. Its association with metastatic disease and microsatellite instability implicates its importance in the development of this tumor type.     

Loss of p63 and cytokeratin 5/6 expression is associated with more aggressive tumors in endometrial carcinoma patients

p63 and cytokeratin (CK) 5/6 are markers of basal and squamous differentiation in several normal epithelia and human tumors and are also suggested to be markers of progenitor or stem cells in certain stratified epithelia. In endometrial carcinoma, there is very limited information about the expression pattern of p63 or CK5/6 and no prognostic information. The aim of our study was to examine whether the expression of these markers was associated with a certain tumor phenotype in terms of other biomarkers, clinicopathologic characteristics and patient prognosis. Immunohistochemical expression of p63 and CK5/6 was examined using tissue microarrays (TMAs) in a large population-based series of 276 endometrial carcinomas with long and complete follow-up. Selected cases of normal and hyperplastic endometrium were examined for comparison (n = 15). Absence of p63 expression (70%) was significantly associated with nonendometrioid carcinomas, high histologic grade (FIGO), higher mitotic count and tumor cell proliferation by Ki-67, microsatellite instability (MSI) and loss of hMSH6 expression. A tendency toward reduced patient survival was also seen (p = 0.098). Presence of CK5/6 expression was more frequent in endometrioid tumors with squamous differentiation, while loss of CK5/6 expression (54%) was significantly associated with high FIGO stage, reduced beta-catenin expression, MSI and reduced patient survival (p = 0.0001); the latter was also found within the endometrioid subgroup (p = 0.0004). Multivariate survival analysis revealed that loss of CK5/6 expression had an independent prognostic impact in addition to well-known prognostic variables. Expression of both markers was increased in simple hyperplasia compared with normal endometrium. In complex hyperplasia, p63 expression was also increased, whereas CK5/6 was positive in areas with squamous differentiation only. Thus, loss of p63 or CK5/6 was associated with features of aggressive tumors, and lack of CK5/6 was significantly associated with reduced survival in multivariate analysis.     

Loss of PTEN expression is an independent predictor of favourable survival in endometrial carcinomas

Background:

We and others previously reported the prognostic significance of PTEN mutational status on favourable survival in endometrial carcinomas. Here, we demonstrate that loss of PTEN expression in immunohistochemistry is an independent prognostic marker for favourable survival in endometrial carcinomas.

Methods:

We conducted immunohistochemical analyses of PTEN, PIK3CA, phosphorylated Akt (p-Akt), and p27 in primary endometrial carcinomas from 221 patients. Mutation of PTEN was analysed further.

Results:

Expression of PTEN was lost in 56 patients (25%), and PIK3CA was overexpressed in 159 patients (72%). Overexpression of PIK3CA was associated with p-Akt overexpression (P<0.001), which was in turn associated with loss of nuclear p27 expression (P=0.028). Loss of PTEN expression was found to be associated with endometrioid histology (P=0.03), and was inversely associated with the presence of lymphovascular space invasion (P=0.03). Univariate and multivariate survival analyses revealed that factors of PTEN loss, age <70, histological grade 1, early International Federation of Gynecology and Obstetrics (FIGO) stage, and absence of lymphovascular invasion were independent prognostic indicators for better overall survival (P=0.03, 0.04, 0.01, <0.001, and 0.03, respectively). The subset analysis showed a stronger tendency of PTEN loss towards favourable survival in advanced-stage (III and IV) disease than in early-stage (I and II) disease (P=0.05 vs 0.14). Moreover, our mutational analysis demonstrated that PTEN expression loss was associated with PTEN-truncating mutations (P=0.03).

Conclusion:

The current observations further support the prognostic significance of PTEN aberration on favourable outcome in endometrial carcinomas, providing useful implications for the individualised management of the disease.     

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.     

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.     

Overexpression of C-erbb-2 protein in endometrial carcinoma is associated with advanced-stage disease

Expression of the c-erbB-2 product (p185(c-erbB-2)) was examined in plasma membrane isolations from 14 uterine endometrial carcinomas and 3 normal endometrial tissues. Overexpression of p185(c-erbB-2) was found in 8 of 9 endometrial carcinomas of stages III and IV and in none of 5 early stage specimens, when compared with the level in normal endometrial tissues. The expression of p185(c-erbB-2) was independent of histological grade. When the p185(c-erbB-2) immunoprecipitated with anti-p185(c-erbB-2) antibodies was exposed to adenosine triphosphate, enhanced self-phosphorylation occurred more frequently in specimens from the tumors carrying p185(c-erbB-2) overexpression. These findings demonstrated positive correlation between disease spread, p185(c-erbB-2) expression and autophosphorylation of p185(c-erbB-2) in human endometrial carcinoma. The prognostic value of these observations awaits continued study.     

Nuclear expression of survivin is associated with improved survival in metastatic ovarian carcinoma

BACKGROUND: Inhibitor of apoptosis proteins (IAPs) mediate cancer cell survival and chemoresistance. The expression of XIAP, Survivin, and Livin in ovarian carcinoma was analyzed. METHODS: Effusions (106) were analyzed for XIAP, Survivin, and Livin expression using immunoblotting. Effusions (220), corresponding primary tumors (60), and solid metastases (103) were further immunohistochemically analyzed for XIAP and Survivin expression. The results were analyzed for association with anatomic site, clinicopathologic parameters, and survival. RESULTS: Immunoblotting showed frequent expression of XIAP and Survivin, and no expression of Livin. Immunohistochemistry showed cytoplasmic XIAP expression in 208 of 220 (94%) effusions, 50 of 60 (83%) primary tumors, and 87 of 103 (84%) solid metastases, with a significantly higher staining extent in effusions (P < .001). Cytoplasmic Survivin was found in 194 of 220 (88%) effusions, 55 of 60 (92%) primary tumors, and 102 of 103 (99%) solid metastases, with a significantly higher cytoplasmic staining extent in solid metastases (P = .018 and P = .006 compared with primary tumors and effusions, respectively). Nuclear Survivin was expressed in 159 of 220 (72%) effusions, 54 of 60 (90%) primary carcinomas, and 96 of 103 (93%) solid metastases (P > .05). For patients with prechemotherapy effusions, higher nuclear Survivin expression correlated with better progression-free (P = .0003) and overall (P = .002) survival in univariate survival analysis. Nuclear Survivin expression was found to be an independent predictor of progression-free survival (P = .004). CONCLUSIONS: XIAP and Survivin, but not Livin, are frequently expressed in ovarian carcinoma. XIAP and cytoplasmic Survivin are up-regulated in effusions and solid metastases, respectively, possibly mediating survival at these sites. Nuclear Survivin expression predicts better outcome in prechemotherapy patients.     

Loss of PBRM1 expression is associated with renal cell carcinoma progression

Although von Hippel‐Lindau (VHL) tumor suppressor gene alterations dominate the genetic landscape of clear cell renal cell carcinoma (ccRCC), recent studies have identified new ccRCC genes, including SETD2, KDM6A, KDM5C, BAP1 and PBRM1. Strikingly, all these genes fall into a category of histone/chromatin regulators. Polybromo‐1 (PBRM1) is the second most frequently mutated gene after VHL; however, the clinical relevance of its loss in ccRCC has not yet been reported. Here, we analyzed the expression of PBRM1, the product encoded by PBRM1, in ccRCC cell lines and in more than 300 RCC tumor samples. The data were correlated with clinicopathological parameters and VHL mutation status. We found that a significant number of ccRCC cancer cell lines lack detectable PBRM1 expression. Loss of PBRM1 was predominant in the clear cell subtype of RCC (～ 70%) and correlated with advanced tumor stage (p < 0.0001), low differentiation grade (p = 0.0002) and worse patient outcome (p = 0.025), but not with the VHL mutation status. Our results indicate a critical role for PBRM1 in the suppression of ccRCC progression. Moreover, the results suggest that functional inactivation of PBRM1 in the context of pVHL loss‐of‐function may represent a key event in facilitating the development of key aspects of an aggressive tumor behavior. Given the role of PBRM1 in chromatin modification, the gene expression pathways disrupted by the inactivation of this protein may lead to new treatment strategies for ccRCC.     

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)     

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     

A gene expression signature associated with metastatic cells in effusions of breast carcinoma patients

Malignant effusion in invasive breast carcinoma is associated with poor prognosis. To decipher molecular events leading to metastasis and to identify reliable markers for targeted therapies are of crucial need. Therefore, we have used cDNA microarrays to delineate molecular signatures associated with metastasis and relapse in breast carcinoma effusions. Taking advantage of an immunomagnetic method, we have purified to homogeneity EpCAM-positive cells from 34 malignant effusions. Immunopurified cells represented as much as 10% of the whole cell fraction and their epithelial and carcinoma features were confirmed by immunofluorescence labeling. Gene expression profiles of 19 immunopurified effusion samples, were analyzed using human pan-genomic microarrays, and compared with those of 4 corresponding primary tumors, 8 breast carcinoma effusion-derived cell lines, and 4 healthy mammary tissues. Principal component and multiple clustering analyses of microarray data, clearly identified distinctive molecular portraits corresponding to the 4 categories of specimens. Of uppermost interest, effusion samples were arranged in 2 subsets on the basis of their gene expression patterns. The first subset partly shares a gene expression signature with the different cell lines, and overexpresses CD24, CD44 and epithelial cytokeratins 8,18,19. The second subset overexpresses markers related to aggressive invasive carcinoma (uPA receptor, S100A4, vimentin, CXCR4). These findings demonstrate the importance of using pure cell fractions to accurately decipher in silico gene expression of clinical specimens. Further studies will lead to the identification of genes of oustanding importance to diagnose malignant effusion, predict survival and tailor appropriate therapies to the metastatic effusion disease in breast carcinoma patients.     

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.     

Inactivation of PTEN is associated with a low p27Kip1 protein expression in breast carcinoma

BACKGROUND: It was previously demonstrated that PTEN protein expression is reduced in 67 of 236 (28%) breast carcinomas. Recent experimental studies suggested that the cell cycle inhibitor p27Kip1 (p27) is a downstream mediator through which PTEN negatively regulates cell cycle progression. METHODS: The immunohistochemic expression of p27 and PTEN protein expression was evaluated in a series of 228 invasive ductal carcinomas of the breast. RESULTS: PTEN protein expression was found to have decreased in 65 of 228 (29%) cases, while the nuclear accumulation of p27 protein was low in 99 of 228 (43%) cases. A reduced PTEN protein expression correlated significantly (P = 0.0214) with a low p27 protein expression. Univariate analysis indicated that the patients demonstrating a combined decrease in PTEN and p27 protein expression have a significantly (P = 0.0044) worse disease-free survival (DFS) than those with other combinations of these two protein expression patterns, while multivariate analysis indicated that the lymph node status, MIB-1 counts, and the combination of PTEN/p27 protein expression (P = 0.0452) are independently significant prognostic factors for DFS. CONCLUSIONS: A reduced PTEN protein expression correlated significantly with a low p27 protein expression in breast carcinoma. The finding that the patients with a combined decrease in both protein expressions had a poor prognosis thus suggests that a combined loss of PTEN and p27 function is associated with an aggressive phenotype in breast carcinoma.     

Loss of PTEN is associated with elevated EGFR and HER2 expression and worse prognosis in salivary gland cancer

Background:

Activity of the tumour-suppressor gene PTEN is reduced in different types of cancer and implicates non-responsiveness to targeted therapy. This study evaluates the gene and protein status of PTEN in salivary gland carcinomas.

Methods:

A total of 287 carcinomas of the major and minor salivary glands were investigated for phosphatase and tensin homologue located on chromosome 10 (PTEN) deletion and loss of PTEN expression using fluorescence in situ hybridisation (FISH) and immunohistochemistry (IHC), respectively. Results were correlated to clinicopathological parameters, long-term survival, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (IHC and FISH) status of the tumours.

Results:

Hemizygous deletions of PTEN were found in 35 out of 232 (15.1%) carcinomas, while homozygous deletions were observed in 17 out of 232 (7.3%) tumours. Phosphatase and tensin homologue located on chromosome 10 deletion was common in certain histological subtypes and especially homozygous deletion was associated with high-grade malignancy, lymph node metastases and unfavourable long-term prognosis (P<0.001). Loss of PTEN expression was present in 59 out of 273 (21.6%) carcinomas and was significantly correlated to genomic PTEN deletion, high-grade malignancy (P<0.001), increased tumour size (P=0.036), lymph node metastases (P=0.007) and worse disease-specific survival (P=0.002). Genomic PTEN deletion, in particular homogenous deletion (P<0.001) predominantly occurred in tumours with increased gene copy number of EGFR (60.0%) and/or amplification of HER2 (63.6%). Loss of PTEN expression was frequently found in tumours overexpressing EGFR (28.6%) and/or HER2 (52.6%).

Conclusion:

PTEN function is reduced in different types of salivary gland cancer indicating unfavourable prognosis. Its association with EGFR and HER2 signalling might affect targeted therapy.     

Loss of Sef (similar expression to FGF) expression is associated with high grade and metastatic prostate cancer

Fibroblast growth factors (FGF), and in particular FGF8, have been strongly implicated in prostate carcinogenesis. This study investigated the expression of Sef, a key inhibitory regulator of FGF signalling, in prostate cancer. In a panel of cell lines, hSef was detected in both androgen-dependent and independent cells but was significantly reduced in highly metastatic derivative clones. hSef expression was not influenced by androgenic stimulation. Forced downregulation of hSef by siRNA increased FGF8b induced cell migration (P=0.02) and invasion (P=0.007). Reduced hSef levels also enhanced FGF8b stimulated expression of MMP9 (P=0.005). mRNA in situ hybridization revealed hSef expression in 80% (8/10) of benign biopsies but in only 69% (23/33) of Gleason sum 4-7 and 35% (10/28) of Gleason sum 8-10 cancer biopsies (P=0.004). Quantitative PCR of microdissected glands confirmed this trend (P=0.001). hSef was expressed in 69% (27/39) of non-metastatic tumours but in only 18% (2/11) of metastatic tumours (P=0.004, n=50). hSef expression was next correlated with earlier data on FGF8b expression in a subgroup of cancers. In this cohort, 86% (19/22) of high-grade cancers expressed FGF8 but only 31% (7/22) expressed hSef. Positive FGF8 expression but a loss of hSef was observed in 88% (7/8) of metastatic tumours. In contrast, metastasis was evident in only 10% (1/10) of tumours, which co-expressed both FGF8 and hSef (P<0.001). These results suggest evidence that hSef is downregulated in advanced prostate cancer and might facilitate an enhanced tumorigenic response to FGFs. Further research into the role of hSef in cancer cell signalling and the mechanism of its downregulation may contribute to more effective targeting of growth factors in prostate cancer.