beta-Catenin functions mainly as an adhesion molecule in patients with squamous cell cancer of the head and neck.

BACKGROUND: beta-catenin, depending on subcellular localization, plays a dual role in carcinogenesis: as a signaling factor (in the nucleus) and as an adhesion molecule (in cell membrane). In this study, we sought to determine the role of beta-catenin in head and neck carcinogenesis. METHODS: First, we studied the incidence of mutations of beta-catenin in a cohort of 60 head and neck squamous cell cancers (HNSCC). We subsequently evaluated the protein expression levels of beta-catenin in a cohort of oropharyngeal squamous cell cancer tissue microarray using a novel in situ method of quantitative protein analysis and correlated those with cyclin D1 levels and clinical and pathologic data. RESULTS: The mean follow-up time for survivors was 45 months and for all patients was 35 months. We found no mutations in the cohort of 60 HNSCC. beta-catenin displayed primarily membranous expression pattern. Patients with high tumor-node-metastasis stage were more likely to have high expression of beta-catenin (P = 0.040). Patients with low beta-catenin expression had a local recurrence rate of 79% compared with 29% for patients with high beta-catenin tumors (P = 0.0021). Univariate Cox regression revealed a hazard ratio for low beta-catenin tumors of 3.6 (P = 0.004). Kaplan-Meier analysis showed that patients with low beta-catenin expressing tumors trended toward worse 5-year disease-free survival (P = 0.06). In multivariate analysis, only beta-catenin expression status was an independent prognostic factor (P = 0.044) for local recurrence. Tumors with high beta-catenin had low cyclin D1 and vice versa (P = 0.007). CONCLUSIONS: The absence of activating beta-catenin mutations combined with the inverse correlation between beta-catenin levels with cyclin D1 levels and outcome suggest that beta-catenin mainly functions as an adhesion and not signaling molecule in HNSCC.     

Aberrant expression of beta-catenin, Pin1 and cylin D1 in salivary adenoid cystic carcinoma: relation to tumor proliferation and metastasis

The aims of this study were to investigate the expression levels of beta-catenin, Pin1 and cyclin D1 in salivary adenoid cystic carcinomas (SACC ) and to evaluate its clinical importance, furthermore, to elucidate whether beta-catenin expression was aberrant in SACC and whether Pin1 was involved in aberrant beta-catenin and cyclin D1 expression. The expression of Pin1, beta-catenin and cyclin D1 were examined in the specimens of 65 patients with SACC by immunohistochemistry, protein and mRNA expressions were detected by western blotting and RT-PCR in four SACC cell lines. Pin1 was overexpressed in 51 cases of SACC (78%), and high levels of Pin1 expression correlated with cyclin D1 positive expression (p = 0.02). Fourteen (22%) cases showed positive immunoreactivity for beta-catenin protein in the nuclear/cytoplasmic fraction in tumor tissues, which was defined as cytoplasm/nucleus staining, among which quite evident nuclear expression of beta-catenin was detected in six cases (9%), while cyclin D1 positive expression was detected in 41 cases of SACC (63%). Reduced membranous expression of beta-catenin was detected in the cases with metastasis (11/14). Theses results suggest that Pin1 and Wnt signalling pathway are activated in SACC and may play a pivotal role in SACC carcinogenesis and metastasis.     

Overexpression of Pin1 in non-small cell lung cancer (NSCLC) and its correlation with lymph node metastases

BACKGROUND: Pin1 isomerizes the bonds of molecules important for numerous oncogenic and cell-signaling pathways, including Bcl-2, p53, c-Jun, beta-catenin, NF-kappaB, cyclin D1, c-Myc and Raf-1. This can cause a change in conformation leading to alterations in catalytic activity, protein-protein interactions, subcellular localization and protein stability. These alterations have been shown to be associated with cell transformation and cancer progression. Pin1 is overexpressed in several different human cancers. This is the first report of Pin1 overexpression in clinical samples of non-small cell lung cancer (NSCLC). METHODS: Protein expression levels of Pin1 in tumor and normal lung specimens were analyzed for expression of Pin1, cyclin D1, p53 and MDM2 using immunohistochemistry and compared to several clinicopathological characteristics. The mRNA expression of Pin1 was also analyzed using quantitative real-time RT-PCR and compared to clinicopathological characteristics. RESULTS: Pin1 protein was shown to be overexpressed in NSCLC tumor samples, and correlated with lymph node positive disease and tumor stage. High expression of MDM2 also correlated with lymph node positive disease and with poorly differentiated tumors. High expression of MDM2 also correlated with lymph node positive disease and with poorly differentiated tumors. High expression levels of Pin1 correlated with high levels of p53 or MDM2 protein, but did not show a correlation with cyclin D1. However, high levels of MDM2 correlated with cyclin D1 overexpression. Pin1 mRNA was expressed significantly more often in the tumors of smokers than of non-smokers. The relationship between the expression of protein and mRNA of Pin1 has obviously showed that protein expression isn't significantly associated with mRNA expression. CONCLUSIONS: Pin1 is overexpressed in many different cancers, including NSCLC, and may possibly be used as a tumor marker or as a target for cancer therapy.     

Tissue microarray analysis of beta-catenin in colorectal cancer shows nuclear phospho-beta-catenin is associated with a better prognosis.

PURPOSE: Beta-catenin is involved in homotypic cell-cell adhesion and the wnt signaling pathway. Deregulation of beta-catenin levels, caused in part by mutations of the adenomatous polyposis coli gene, is thought to play a role in the development of colorectal and other cancers. To further elucidate their roles, the expression pattern of beta-catenin and phosphospecific beta-catenin was correlated with clinical outcome in a series of patients with colorectal cancer. EXPERIMENTAL DESIGN: Immunohistochemical analysis of a tissue microarray with 650 colorectal cancer specimens was performed to study the expression and subcellular localization of beta-catenin and phosphospecific beta-catenin. These results were correlated with other clinicopathological factors and with overall survival. RESULTS: The majority of cancers retained some degree of beta-catenin membranous staining, whereas cytoplasmic or nuclear expression was seen in 42.5% and 20.4% of specimens, respectively. Phospho-beta-catenin showed nuclear staining in 9.5% of specimens, and there was no apparent membranous or cytoplasmic staining. There was no significant association between beta-catenin or phospho-beta-catenin and grade or stage. However, there was a positive correlation between beta-catenin and phospho-beta-catenin (P = 0.039), with phospho-beta-catenin representing a subset of nuclear beta-catenin. Patients with nuclear expression of beta-catenin did not have an altered survival compared with those that did not (P = 0.5611). Nuclear expression of phospho-beta-catenin, however, was associated with an improved survival (P = 0.0006). In multivariate analysis, only stage and phospho-beta-catenin were independently predictive of overall survival (P < 0.001 and P = 0.0034, respectively). CONCLUSIONS: These findings support a role for beta-catenin overexpression in colorectal tumorigenesis and provide initial evidence that phospho-beta-catenin may be a marker for improved overall survival independent of stage and grade.     

Multiple mechanisms are involved in 6-gingerol-induced cell growth arrest and apoptosis in human colorectal cancer cells

6-Gingerol, a natural product of ginger, has been known to possess anti-tumorigenic and pro-apoptotic activities. However, the mechanisms by which it prevents cancer are not well understood in human colorectal cancer. Cyclin D1 is a proto-oncogene that is overexpressed in many cancers and plays a role in cell proliferation through activation by beta-catenin signaling. Nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1) is a cytokine associated with pro-apoptotic and anti-tumorigenic properties. In the present study, we examined whether 6-gingerol influences cyclin D1 and NAG-1 expression and determined the mechanisms by which 6-gingerol affects the growth of human colorectal cancer cells in vitro. 6-Gingerol treatment suppressed cell proliferation and induced apoptosis and G(1) cell cycle arrest. Subsequently, 6-gingerol suppressed cyclin D1 expression and induced NAG-1 expression. Cyclin D1 suppression was related to inhibition of beta-catenin translocation and cyclin D1 proteolysis. Furthermore, experiments using inhibitors and siRNA transfection confirm the involvement of the PKCepsilon and glycogen synthase kinase (GSK)-3beta pathways in 6-gingerol-induced NAG-1 expression. The results suggest that 6-gingerol stimulates apoptosis through upregulation of NAG-1 and G(1) cell cycle arrest through downregulation of cyclin D1. Multiple mechanisms appear to be involved in 6-gingerol action, including protein degradation as well as beta-catenin, PKCepsilon, and GSK-3beta pathways.     

Pin1、β-连接素和细胞周期素D1在老年肺癌组织中的表达及临床意义

Objective:To investigate the expressions and correlations of Pin1,β-catenin and cyclin D1 in elderly lung carcinomas.Methods:The expressions of Pin1,β-catenin and cyclin D1 were examined in the specimens of 92 elderly lung carcinomas and 10 normal lung tissues by immunohistochemistry and explored the relationship between the expression levels and clinicopathological factors.Results:(1) The overexpression of Pin1 and cyclin D1 in lung carcinomas was 46 (50%)cases and 60 (65.22%) cases respectively and 56 (60.82%) cases showed positive immunoreactivity for β-catenin in the nuclear and (or) cytoplasmic fraction in tumor tissues,In normal tissue,the expressions of Pin1 and cyclin D1 were negative,the expression of β-catenin was lied in cell membrane.(2) In lung carcinomas the expressions of Pin1,β-catenin and cyclin D1 correlated with tumor differentiation (P＜0.05).The pesitive expression rate and intensity of Pin1 correlated with tumor stage (P=0.032) and lymph node positive disease (P=0.041).The expression of β-catenin correlated with lymph node positive disease (P=0.012).(3) High expression levels of Pin1 correlated with aberrant β-catenin expression (P=0.000) but did not show a correlation with cyclin D1 (P=0.157).Conclusion:In elderly lung carcinomas,the positive expression of Pin1 causes abnormal accumulation of β-catenin and actives its target gene,however,this target gene was not cyclin DI.The detection of Pin1 expression had some clinical significance in estimating prognosis of elderly patient with lung carcinomas.     

宫颈癌细胞株和宫颈上皮组织中Pin1和Cyclin D1的表达及临床意义

背景与目的：肽基脯氨酰顺反异构酶Pin1在人类多种肿瘤中过表达,Pin1过表达可增强Cyclin D1表达,在肿瘤发生发展中起重要作用。本研究拟探讨宫颈癌细胞株及宫颈上皮组织中Pin1、Cyclin D1的表达及其临床意义。方法：应用RT-PCR、Western blot法检测HeLa、SiHa、C33a、Caski细胞中Pin1和Cyclin D1基因蛋白表达,免疫组化法检测10例正常宫颈、21例宫颈上皮内瘤样病变、57例浸润癌组织中Pin1和Cyclin D1的表达状况,评价其临床意义。结果：HeLa、SiHa、C33a、Caski细胞存在不同程度Pin1 mRNA及蛋白过表达（P〈0．05）。正常宫颈、宫颈上皮内瘤样病变、浸润癌组织中Pin1蛋白表达逐渐增强,分别为0％、47．62％、64．91％（P〈0．05）。Pin1蛋白过表达与宫颈癌临床分期、病理分级、淋巴结转移无关（P〉0．05）;但宫颈腺癌组织中Pin1表达明显高于鳞癌（P〈0．05）。Pin1过表达与Cyclin D1表达呈显著正相关（P〈0．05）。结论：Pin1在宫颈癌细胞株及宫颈癌组织中存在mRNA及蛋白水平上的过表达。Pin1过表达与Cyclin D1表达密切相关．Pin1和Cyclin D1异常表达可能参与宫颈癌的发生发展。     

Reduced membranous and ectopic cytoplasmic expression of beta -catenin correlate with cyclin D1 overexpression and poor prognosis in pancreatic cancer

Beta-catenin is a component of the E-cadherin-catenin cell adhesion complex. It plays also a role in intracellular signaling and can function as an oncogene when it binds to the T-cell factor 4 (Tcf4)-binding site in the promoter region of cyclin D1 and transactivates genes after translocation to the nucleus. We evaluated the immunohistochemical expression pattern of beta-catenin in relationship with cyclin D1 overexpression, tumor grade, clinicopathologic parameters and patients' survival in 43 ductal adenocarcinomas of the pancreas and 5 normal pancreatic tissues. We were able to show that, both reduced membranous beta-catenin expression (25 of 43, 58.1%) and accumulation of beta-catenin in the cytoplasm (28 of 43, 65.1%) correlated significantly with cyclin D1 overexpression (both p < 0.0005). Furthermore, we could show a clear correlation between reduced membranous expression and ectopic cytoplasmic expression of beta-catenin (p < 0.0005). Among patients with carcinomas showing no cytoplasmic expression, the 1-year survival was 86.6% whereas among patients with carcinomas showing cytoplasmic expression only 35.7% survived 1 year (p < 0.01). Co-precipitation experiments revealed reduced beta-catenin bound to the E-cadherin-catenin complex in pancreatic tumor tissues compared with normal pancreatic tissues. These results suggest that beta-catenin may be involved in the tumorigenesis of pancreatic cancer and exhibited its effects mainly by the transactivation of cyclin D1.     

p53、Cyclin D1及PCNA在非小细胞肺癌的表达

目的 研究非小细胞肺癌（NSCLC）中p53、Cyclin D1蛋白表达及与细胞增殖的关系。方法 应用免疫组织化学技术（SP法）检测74例NSCLC中p53、Cyclin D1蛋白和增殖细胞抗原（PCNA）的表达情况。结果 p53蛋白、CyclinD1蛋白在NSCLC中阳性表达率分别为55．41％和37．84％,均明显高于正常肺组织（P1＝0．0031,P2＝0．0429）。 p53蛋白表达与淋巴结转移有密切关系（P＝0．0222）。p53蛋白、CyclinD1蛋白表达分别与PCNA指数有密切关系（P1＝0．001,P2＝0．0009）。p53蛋白与CyclinD1蛋白表达之间未见明显关系（P＞0．05）。结论 p53蛋白和CyclinD1蛋白近表达参与了NSCLC的发生发展,有促进细胞增殖的作用。p53的诊断和评价NSCLC预后的重要参数。     

Loss of cyclin D1 and p16 expression correlates with local recurrence in nasopharyngeal carcinoma following radiotherapy.

BACKGROUND: The cyclin D1/p16/Rb pathway plays a critical role in tumorigenesis and each component of this pathway may be affected in various malignancies. The purpose of this study was to investigate the expression and prognostic significance of these proteins in nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: Sixty-five patients undergoing radiotherapy for NPC were analyzed. The expression of cyclin D1, p16 and pRb was evaluated with immunohistochemical analysis of archived pretreatment tumor materials and expression of these proteins was correlated with clinicopathological parameters. RESULTS: Positive expression of cyclin D1 was observed in 43 of 65 NPCs (66%). p16 and pRb inactivation was identified in 42 of 65 (65%) and four of 65 (6%) tumors, respectively. All but seven tumors (58 of 65, 89%) contained at least one alternation in the cyclin D1/p16/Rb pathway. Loss of cyclin D1 as well as p16 was closely related to local recurrence after radiotherapy for NPC (P = 0.015 and 0.047). No association between pRb expression and clinicopathological outcome was apparent. CONCLUSIONS: The study's results suggest that the cyclin D1/p16/Rb pathway plays an important role in NPC tumorigenesis. We also find that cyclin D1 and p16 protein levels in NPC may be of use clinically as a predictor of local tumor control.     

非小细胞肺癌中DEC1与cyclin D1的表达及其临床意义

目的:分析differentiated embryonic chondrocyte expressed gene 1（DEC1）和cyclin D1在非小细胞肺癌组织中的表达和相关性及其与临床病理因素间的关系。方法:采用免疫组化方法检测DEC1和cyclin D1在134例非小细胞肺癌中的表达情况。结果:在134例非小细胞肺癌中,DEC1细胞核的平均阳性表达率为（27.6±9.26）%,明显低于DEC1癌旁正常组织中细胞核的平均阳性表达率（84.3±19.70）%。DEC1表达下调或缺失与肺癌的低分化（P=0.008）以及高p-TNM分期(P=0.001)相关。而cyclin D1表达与肺癌低分化（P=0.003）,肿瘤大小（P=0.038）,高p-TNM分期（P=0.017）及淋巴结转移（P=0.037）正相关。并且DEC1在肺癌中的细胞质表达与cyclin D1的表达显著负相关（P=0.003）。结论:DEC1表达与cyclin D1表达负相关,并与肿瘤分化,肺癌患者高p-TNM分期负相关。     

Increased expression of beta-catenin predicts better prognosis in nonsmall cell lung carcinomas

BACKGROUND: beta-Catenin has been shown to function as a Wnt signaling molecule to stimulate cyclin D1 expression and cell growth in several kinds of tumors. METHODS: The authors immunohistochemically examined specimens of 217 surgically resected primary nonsmall cell lung carcinomas (NSCLCs) for beta-catenin expression and classified them semiquantitatively into three categories, including those with high, moderate, and low scores of expression. RESULTS: High, moderate, and low scores of expression were found in 37 (17.1%), 145 (66.8%), and 35 (16.1%) tumors, respectively. beta-Catenin expression was not correlated with cyclin D1 expression, but was positively correlated with the Ki-67 cell growth fraction (P = 0.04). The direct sequencing analysis for the beta-catenin gene mutation of 13 specimens of 217 tumors for the current study revealed no mutations. The relation between survival and beta-catenin expression was evaluated in 148 potentially curatively resected tumors with pathologic Stages I-IIIA. A trend toward better survival was found in patients with tumors having higher scores. In multivariate analysis, high beta-catenin expression was a significant and independent favorable prognostic factor (hazards ratio, 0.31; P = 0.007) as was pathologic stage. Analyzed by cell type, in nonsquamous cell carcinomas, patients with tumors having high scores survived a significantly longer time than those with tumors having moderate or low scores (5-year survival rates, 84%, 55%, and 32%, respectively; P = 0.02), and high beta-catenin expression tended to be a favorable prognostic factor (hazards ratio, 0.32; P = 0.052). CONCLUSIONS: These results indicate that, in NSCLCs, increased expression of beta-catenin can predict favorable prognosis of patients with resected tumors, suggesting that accumulation of beta-catenin has no or little oncogenic effect via activation of the Wnt pathway, unlike in colon carcinomas or hepatomas.     

应用组织芯片检测食管鳞状细胞癌中APC、β-catenin、E-cadherin与cyclinD1的表达及其意义

背景与目的：食管鳞状细胞癌（esophageal squamous cell carcinoma,ESCC）的发生是个多因素多阶段的演进过程。Wnt信号转导通路在肿瘤发生发展中起重要作用。本研究探讨4种Wnt通路上的蛋白在食管鳞癌发生中的作用及在早期诊断中的意义。方法：制作由199例食管鳞癌组织与其癌旁164例正常粘膜、34例基底细胞增生和30例不典型增生上皮组成的组织芯片,应用免疫组化方法检测APC、 β-catenin、E-cadherin、cyclin D1的表达情况。结果：APC和E-cadherin在ESCC阳性率分别是69．6％、19．6％,均低于各自正常组（98．0％、96．3％,均为P〈0．01）, β-catenin和cyclin D1在ESCC的异常表达率分别是65．5％和70．9％,均高于各自正常组（1．2％,0．8％,均为P〈0．01）。按正常粘膜→基底细胞增生→不典型增生→ESCC的顺序,APC低表达发生在ESCC, β-catenin和E-cadherin表达异常始于不典型增生．cyclinD1过表达始于基底细胞增生。随着ESCC分化程度由高到低的改变,APC、E．cadherin和cyclinD1阳性率逐渐减少, β-catenin逐渐增加。 β-catenin的表达与APC无相关（r=-0．10,P〉0．05）,与E．cadherin呈负相关（r=-0．31,P〈0．01）,与cyclinD1呈正相关（r=0．49,P〈0．01）。结论：APC、E-cadherin、 β-catenin和cyclinD1可能在ESCC发生过程中起重要作用。 β-catenin、E-Cadherin和cyclinD1的表达检测有助于ESCC的早期诊断。     

Pin1 inhibition potently suppresses gastric cancer growth and blocks PI3K/AKT and Wnt/β‐catenin oncogenic pathways

Gastric cancer is the second leading cause of cancer‐related mortality and the fourth most common cancer globally. High intratumor heterogeneity of advanced gastric cancer poses great challenges to targeted therapy due to simultaneous activation of many redundant cancer‐driving pathways. A central common signaling mechanism in cancer is proline‐directed phosphorylation, which is further regulated by the unique proline isomerase Pin1. Pin1 inhibition exerts anticancer activity by blocking multiple cancer‐driving pathways in some cancers, but its role in gastric cancer is not fully understood. Here we detected Pin1 protein expression in 1065 gastric cancer patients and paired normal tissues using immunohistochemistry and Western blot, and then examined the effects of Pin1 overexpression, and genetic and chemical Pin1 inhibition using Pin1 short hairpin RNA or small molecule inhibitor all‐trans retinoic acid (ATRA) on tumorigenesis of human gastric cancer in vitro and in vivo, followed by biochemical analyses to elucidate Pin1 regulated oncogenic pathways. We found that Pin1 was significantly overexpressed in primary and metastasized tumors, with Pin1 overexpression being correlated with advanced stage and poor prognosis. Furthermore, whereas Pin1 overexpression promoted the transformed phenotype in immortalized and nontransformed human gastric cells, either genetic or chemical Pin1 inhibition in multiple human gastric cancer cells potently suppressed cell growth, G1/S transition and colony formation in vitro, as well as tumor growth in xenograft tumor models in vivo, which were further supported by downregulation of multiple key oncoproteins in PI3K/AKT and Wnt/β‐catenin signaling pathways. These results not only provide the first evidence for a critical role of Pin1 in the tumorigenesis of gastric cancer but also suggest that targeting Pin1 using ATRA or other inhibitors offers an effective new therapeutic approach for treating advanced gastric cancer.     

beta-Catenin activates the growth factor endothelin-1 in colon cancer cells

Endothelin-1 (EDN1) is a growth factor that is frequently produced by cancer cells and plays a critical role in tumorigenesis. However, the molecular mechanism controlling the expression of EDN1 in cancers is unknown. Constitutive activation of beta-catenin pathway is responsible for the initiation of the vast majority of colon cancers. Here we show that the EDN1 gene is directly regulated by beta-catenin in colon cancer cells. A specific DNA element within the EDN1 promoter is required for activation, and is associated with beta-catenin's cognate DNA binding partner, TCF4, in vivo. Inhibition of beta-catenin signaling results in lowered expression of EDN1, while enhancement of beta-catenin signaling leads to further activation of the gene. Significantly elevated EDN1 expression occurs in 80% of primary human colon cancers, consistent with it being a direct target of beta-catenin. Furthermore, EDN1 is able to rescue colon cancer cells from growth arrest and apoptosis resulting from inhibition of beta-catenin signaling, implicating a key role of EDN1 in promoting the oncogenic function of beta-catenin. These results indicate EDN1 overexpression as a major cause in colon cancers and reveal further details of the genetic programs responsible for tumorigenesis of colon cancers.