Expression of CD44v6 but not E-cadherin or beta-catenin influences prognosis in primary pulmonary adenocarcinoma

Consensus clustering and novel risk score model construction based on m6A methylation regulators to evaluate the prognosis and tumor immune microenvironment of early-stage lung adenocarcinoma

BACKGROUND

The aim of this study was to investigate the correlation between m6A methylation regulators and cell infiltration characteristics in tumor immune microenvironment (TIME), so as to help understand the immune mechanism of early-stage lung adenocarcinoma (LUAD).

METHODS

The expression and consensus cluster analyses of m6A methylation regulators in early-stage LUAD were performed. The clinicopathological features, immune cell infiltration, survival and functional enrichment in different subtypes were analyzed. We also constructed a prognostic model. Clinical tissue samples were used to validate the expression of model genes through real-time polymerase chain reaction (RT-PCR). In addition, cell scratch assay and Transwell assay were also performed.

RESULTS

Expression of m6A methylation regulators was abnormal in early-stage LUAD. According to the consensus clustering of m6A methylation regulators, patients with early-stage LUAD were divided into two subtypes. Two subtypes showed different infiltration levels of immune cell and survival time. A prognostic model consisting of HNRNPC, IGF2BP1 and IGF2BP3 could be used to predict the survival of early-stage LUAD. RT-PCR results showed that HNRNPC, IGF2BP1 and IGF2BP3 were significantly up-regulated in early-stage LUAD tissues. The results of cell scratch assay and Transwell assay showed that overexpression of HNRNPC promotes the migration and invasion of NCI-H1299 cells, while knockdown HNRNPC inhibits the migration and invasion of NCI-H1299 cells.

CONCLUSIONS

This work reveals that m6A methylation regulators may be potential biomarkers for prognosis in patients with early-stage LUAD. Our prognostic model may be of great value in predicting the prognosis of early-stage LUAD.

Association of CD44 gene rs187115 polymorphism with colorectal cancer risk and prognosis in Chinese Han population: a case-control study

The cell surface adhesion receptor CD44 reportedly affects the development and progression of cancers. Moreover, CD44 gene rs187115 polymorphism appears to be genetic determinant of cancer susceptibility. We investigated whether CD44 rs187115 polymorphism is associated with colorectal cancer (CRC) risk and prognosis. We enrolled 669 CRC cases and 826 controls in this three-center case-control study in a Chinese Han population. All individuals were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Cross-over analysis, multivariate logistic regression, Kaplan-Meier method, and Cox regression analysis were used for analysis. In this study, CD44 rs187115 polymorphism was associated with increased risk for CRC. Stratified analyses revealed that CD44 rs187115 polymorphism was correlated with increased risk for CRC in females, drinkers, smokers, and those aged ≥ 60 years. In addition, rs187115 polymorphism was significantly associated with TNM III+IV stage, lymph node metastasis and tumor size in CRC patients. Combined effects of CD44 rs187115 polymorphism (GG/AG vs. AA) and environmental factors (smoking and drinking) further increased the risk of CRC. GG genotype carriers showed poorer overall survival than AA genotype carriers. Cox regression analysis showed that drinking, CD44 rs187115 polymorphism, and TNM stage were independent prognostic factors affecting CRC. These findings show that CD44 rs187115 polymorphism may be a potential biomarker predictive of CRC susceptibility and prognosis.

Association of CD44 Gene Polymorphism with Survival of NSCLC and Risk of Bone Metastasis

Background

Previous studies have reported CD44 expression influenced the development and progression of tumors. The aim of this study was to investigate whether single-nucleotide polymorphisms (SNPs) of the CD44 gene are associated with survival of non-small cell lung cancer (NSCLC) and occurrence rate of bone metastasis.

Material/Methods

A total of 234 patients with NSCLC between 2003 and 2010 were enrolled in this study and 468 healthy persons were used as controls. Two polymorphisms, rs13347 and rs187115, in the CD44 gene were genotyped using DNA from blood lymphocytes. For statistical analysis we used the chi-square test, Fisher’s exact test, Kaplan-Meier method, and log-rank test.

Results

CD44 gene rs13347 polymorphism was not associated with NSCLC risk. For rs187115, the association with NSCLC risk was observed (P<0.001). Allele G carriers had significantly higher occurrence rates of bone metastasis (OR=0.4, 95%CI: 0.20–0.64, P<0.001) and more advanced tumor stage (OR=2.6, 95%CI: 1.50–4.45, P=0.001) compared to carriers of allele A. The survival rates for patients with AA genotype were significantly higher than for patients with the AG+GG genotypes (P<0.001). In multivariate analysis of survival in NSCLC patients, significant predictors were CD44 gene (AG+GG) (RR=0.48, 95%CI: 0.34–0.68, P<0.001), tumor stage (RR=0.45, 95%CI: 0. 0.31–0.65, P<0.001), and bone metastasis (RR=1.52, 95%CI: 1.05–2.21, P=0.027).

Conclusions

CD44 gene rs187115 polymorphism is a potential predictive marker of survival in NSCLC patients, and is significantly correlated with bone metastasis and tumor stage.

Prognostic value of CD44 variant exon 6 expression in non-small cell lung cancer: a meta-analysis

BACKGROUND

CD44v6 (CD44 variant exon 6) is the chief CD44 variant isoform regulating tumor invasion, progression, and metastasis. The prognostic value of CD44v6 expression in non small cell lung cancer (NSCLC) has been evaluated in many studies, but the results have remained controversial. Thus, we performed a meta- analysis of currently available studies to investigate the prognostic value of CD44v6 expression in NSCLC patients and the relationship between the expression of CD44v6 and clinicopathological features.

MATERIALS AND METHODS

Two independent reviewers searched the relevant literature in Pubmed, Medline and Embase from 1946 to January 2014. Overall survival (OS) and various clinicopathological features were collected from included studies. This meta-analysis was accomplished using STATA 12.0 and Revman 5.2 software. Pooled hazard ratios (HRs) with 95% confidence intervals (95%CIs) were calculated to estimate the effects.

RESULTS

A total of 921 NSCLC patients from ten studies met the inclusion criteria. The results showed that CD44v6 high expression was a prognostic factor for poor survival (HR=1.91, 95%CI=1.12-3.26, p<0.05). With respect to clinicopathological features, CD44v6 high expression was related to histopathologic type (squamous cell carcinoma versus adenocarcinoma: OR=2.72, 95%CI=1.38-5.38, p=0.004), and lymph node metastasis (OR=3.02, 95%CI=1.93-4.72, p<0.00001).

CONCLUSIONS

Our results suggested CD44v6 high expression as a poor prognostic factor for NSCLC, and CD44v6 expression is associated with lymph node metastasis and histopathologic type. Therefore, CD44v6 expression can be used as a novel prognostic marker in NSCLC cases.

Expression of calcium sensing receptor and E-cadherin correlated with survival of lung adenocarcinoma

Background

It has been reported that the calcium sensing receptor (CaSR), a widely expressed G protein-coupled receptor, can stimulate cell differentiation and proliferation. However, in malignant tumors, loss of CaSR expression has been associated with tumorigenesis, metastasis, and progression. Recent studies have indicated that the CaSR could promote the expression of E-cadherin, which was considered a tumor suppressor. However, in human lung adenocarcinoma, the importance of the CaSR and E-cadherin has not been sufficiently investigated.

Methods

Expression levels of CaSR and E-cadherin in paraffin sections from 117 resected lung adenocarcinoma patients were evaluated by immunohistochemistry. We analyzed the correlation between our target proteins and clinical variables. Clinical significance was analyzed by multivariate Cox regression analysis, Kaplan–Meier curve, and log-rank test.

Results

Expression of the CaSR in lung adenocarcinoma tissue was significantly lower than in the normal sample (P = 0.003). Kendall tau-b analysis showed that, in a lung adenocarcinoma sample, the expression of CaSR positively correlated with a high level of E-cadherin (P < 0.001). Lung adenocarcinoma patients with a strong expression of CaSR (P = 0.034) or E-cadherin (P = 0.001) had longer overall survival. Multivariate Cox proportional hazards model analysis showed that the combined marker was an independent prognostic indicator of overall survival (hazard ratio = 0.440, confidence interval = 0.249–0.779, P = 0.005).

Conclusions

We identified the CaSR as a new prognostic biomarker in lung adenocarcinoma. These results also suggested that the CaSR may become a new therapeutic target of lung adenocarcinoma.

Prognostic value of CD44 and CD44v6 expression in patients with non-small cell lung cancer: meta-analysis

We sought to clarify the prognostic value of CD44 in survival of patients with non-small cell lung cancer (NSCLC). We performed a meta-analysis of relevant literature to aggregate the available survival results, using studies published in English until March 2014. Eligible studies dealt with CD44, CD44 standard form (CD44s) and CD44 variant 6 (CD44v6), assessment in NSCLC patients on primary lesions and reported survival data according to CD44 and CD44 isoforms expression. We aggregated 10 trials (5 trials for CD44v6, 3 trials for CD44, and 2 trials for CD44s) comprising 1,074 patients, in this meta-analysis. The combined hazard ratio (HR) with CD44v6 and CD44s was 2.39 (95 % confidence interval (CI) 1.69-3.37) and 1.64 (95 % CI 1.06-2.52), respectively. It associated high CD44v6 and CD44s expression with poor survival in NSCLC patients. However, CD44 overexpression did not significantly correlate with survival in patients with NSCLC (HR 1.44; 95 % CI 0.72-2.89). Our meta-analysis shows that CD44v6 and CD44s overexpression indicates poor prognosis for NSCLC patients. However, the high CD44 expression is not significantly correlated with survival for patients with NSCLC.

DDX3 loss by p53 inactivation promotes tumor malignancy via the MDM2/Slug/E-cadherin pathway and poor patient outcome in non-small-cell lung cancer

P53 inactivation by p53 mutation and E6 oncoprotein has a crucial role in human carcinogenesis. DDX3 has been shown to be a target of p53. In this study, we hypothesized that DDX3 loss by p53 inactivation may promote tumor malignancy and poor patients' outcome. Mechanically, DDX3 loss by p53 knockdown and E6 overexpression was observed in A549 lung cancer cells. Conversely, DDX3 expression was markedly elevated by wild-type (WT) p53 ectopic expression in p53-null H1299 cells, E6-knockdown TL-1 lung cancer and SiHa cervical cancer cells. Interestingly, DDX3 loss promotes soft-agar growth and invasive capability; however, both capabilities were suppressed by DDX3 overexpression. We next expected that DDX3 loss might result in Slug-suppressed E-cadherin expression via decreased MDM2-mediated Slug degradation. As expected, MDM2 transcription is suppressed by DDX3 loss via decreased SP1 binding activity to the MDM2 promoter. Consequently, Slug expression was elevated by the reduction of MDM2 because of DDX3 loss, and E-cadherin expression was suppressed by Slug. Consistent observations in the correlation of DDX3 loss with MDM2, Slug and E-cadherin were seen in lung tumors from lung cancer patients. In addition, patients with low-DDX3 tumors had poorer survival and relapse than patients with high-DDX3 tumors. In conclusion, we suggest that DDX3 loss by p53 inactivation via MDM2/Slug/E-cadherin pathway promotes tumor malignancy and poor patient outcome.

Beta-catenin expression is prognostic of improved non-small cell lung cancer survival

INTRODUCTION

The objectives of this study were to determine the frequency and prognostic significance of beta-catenin expression in a cohort of non-small cell lung cancer (NSCLC) patients.

METHODS

Tissue microarrays were constructed using clinically annotated formalin-fixed paraffin-embedded tumor samples from individuals diagnosed with NSCLC who underwent surgical resection with curative intent and had beta-catenin expression status determined by immunohistochemistry.

RESULTS

Negative beta-catenin expression was seen in 28% (103/370) of NSCLC cases and was prognostic of a reduced overall patient survival (P = .008) and also was significantly correlated with the presence of lymphatic invasion (P = .015). In multivariate analysis, the loss of beta-catenin expression retained independent prognostic significance and showed an adjusted hazard ratio of 3.18 (confidence interval, 1.46-6.91, P = .004) for reduced patient survival when adjusting for the presence of lymphatic invasion, tumor grade, nodal status, and tumor stage.

CONCLUSIONS

Beta-catenin represents an important prognostic marker in individuals diagnosed with surgically resectable NSCLC.

CD133 and CD44 are universally overexpressed in GIST and do not represent cancer stem cell markers

Although imatinib mesylate has been a major breakthrough in the treatment of advanced gastrointestinal stromal tumors (GIST), complete responses are rare and most patients eventually develop resistance to the drug. Thus, the possibility of an imatinib-insensitive cell subpopulation within GIST tumors, harboring stem cell characteristics, may be responsible for the clinical failures. However, the existence of a cancer stem cell component in GIST has not been yet established. This study was aimed to determine whether expression of commonly used stem cell markers in other malignancies, that is, CD133 and CD44, might identify cells with characteristics of cancer stem/progenitor cells in human GIST. CD133 and CD44 expression in GIST explants was analyzed by flow cytometry, immunofluorescence, and gene expression. Their transcription levels were correlated with clinical and molecular factors in a large, well-annotated cohort of GIST patients. FACS sorted GIST cells based on CD133 and CD44 expression were isolated and used to assess phenotypic characteristics, ability to maintain their surface expression, sensitivity to imatinib, and expression signature. The enrichment in CD133/CD44 cells in the side population (SP) assay was also investigated. CD133 expression was consistently found in GIST. CD133(-) cells formed more colonies, were more invasive in a matrigel assay, and showed enrichment in the SP cells, compared to CD133(+) cells. CD133 expression was also detected in the two imatinib-sensitive GIST cell lines, while was absent in the imatinib-resistant lines. Our results show that CD133 and CD44 are universally expressed in GIST, and may represent a lineage rather than a cancer stem cell marker.

Expression of CD44s and CD44v6 in lung cancer and their correlation with prognostic factors

BACKGROUND

CD44, a transmembrane glycoprotein receptor, plays a major role in tumor progression and metastasis.

OBJECTIVE

To evaluate the expression of CD44 standard (CD44s) and its variant 6 (CD44v6) in normal and neoplastic lung tissue and correlate it with prognostic factors in lung cancer.

METHODS

The study included 52 non-small cell lung carcinomas (NSCLC) (21 squamous cell carcinomas and 31 adenocarcinomas), 15 small cell lung carcinomas (SCLC) and 8 carcinoid tumors. Expression of CD44s and CD44v6 was evaluated by immunohistochemistry and correlated with lung cancer prognostic factors.

RESULTS

All squamous cell carcinomas expressed both CD44s and CD44v6. Adenocarcinomas expressed CD44s in 39% of cases and CD44v6 in 45%. Carcinoid tumors expressed only CD44s in 88% of cases. All SCLCs were negative for both CD44s and CD44v6. A restricted panel consisting of CD44s and CD44v6 will discriminate NSCLC from SCLC with a sensitivity of 67% and a specificity of 100%. In adenocarcinoma CD44s expression was significantly correlated with lymph node metastases (p=0.007) while CD44v6 expression was more significantly associated with tumor size (p=0.0032).

CONCLUSIONS

CD44s and CD44v6 are expressed in certain types of lung cancer. In adenocarcinoma CD44s and CD44v6 expression is significantly correlated with lymph node metastases and tumor size.

Prognostic significance of CD44s expression in resected non-small cell lung cancer

Background

CD44s is a cell adhesion molecule known to mediate cellular adhesion to the extracellular matrix, a prerequisite for tumor cell migration. CD44s plays an important role in invasion and metastasis of various cancers. In the present study, we sought to determine whether CD44s is involved in clinical outcomes of patients with resected non-small cell lung cancer (NSCLC).

Methods

Using immunohistochemical staining, we investigated CD44s protein expression using tissue array specimens from 159 patients with resected NSCLC (adenocarcinoma (AC; n = 82) and squamous cell carcinoma (SCC; n = 77). Additionally, the immunoreactivity of cyclooxygenase (COX)-2 was also studied. The clinicopathological implications of these molecules were analyzed statistically.

Results

High CD44s expression was detected more frequently in NSCLC patients with SCC (66/72; 91.7%) than in those with AC histology (P <0.001). Additionally, high CD44s expression was significant correlated with more advanced regional lymph node metastasis (P = 0.021). In multivariate analysis of survival in NSCLC patients with AC histology, significant predictors were lymph node metastasis status (P < 0.001), high-grade tumor differentiation (P = 0.046), and high CD44s expression (P = 0.014). For NSCLC patients with SCC histology, the significant predictor was a more advanced tumor stage (P = 0.015). No significant association was found between CD44s and clinical outcome (P = 0.311).

Conclusions

High CD44s expression was a negative prognostic marker with significance in patients with resected NSCLC, particularly those with AC histology, and was independent of tumor stage.

Significance of site-specific prognosis of cancer stem cell marker CD44 in head and neck squamous-cell carcinoma

In several recent studies, CD44 expression has been associated with aggressive behavior in cancers of different types. CD44 expression is also linked to cancer stem cells, which have been shown to play a significant role in tumor progression and poor prognosis in head and neck squamous cell carcinoma (HNSCC), as well as in other cancers. Although CD44 is a potential prognostic marker, it has not been adopted to wider clinical use as a part of treatment planning in HNSCC patients. The aim of this research was to study whether CD44 overexpression is associated with 5year overall survival in HNSCC. We also studied site-specific associations between increased CD44 expression and 5year overall survival. Associations between relative tumor CD44 expressions and smoking, heavy alcohol consumption, histological grade of cancer, TNM staging and HNSCC staging were also studied. In total, 135 paraffin-embedded blocks from HNSCC patients were stained immunohistochemically with a CD44 antibody and were classified by the anatomic location of the tumor. CD44 overexpression had statistically significant association with decreased 5year survival rates when all HNSCC samples were studied (p<0.001). Significant association between intense CD44 expression and poor 5year survival rates was found in the patients with SCC of the oro- and hypopharynx (p<0.001) and the larynx (p=0.042). In patients suffering from HNSCC in the oral cavity, CD44 overexpression did not have a significant effect on overall 5year survival rates. Heavy smoking of over 10 pack years had a significant association with tumor CD44 overexpression (p=0.009). Only pharyngeal (p=0.046) and laryngeal (p=0.047) SCC, but not oral-cavity SCC, had statistically significant associations between heavy smoking and CD44 overexpression when HNSCC was studied in regional groups. Alcohol consumption and tumor grade did not have a significant association with the tumor's CD44 expression. Our results suggest that CD44 overexpression could be used as a sign of aggressiveness, in addition to the HNSCC staging, as a prognostic factor in pharyngeal and laryngeal HNSCC and to assist in treatment selection.

Paxillin predicts survival and relapse in non-small cell lung cancer by microRNA-218 targeting

Paxillin (PXN) gene mutations are associated with lung adenocarcinoma progression and PXN is known to be a target gene of microRNA-218 (miR-218). On this basis, we hypothesized that PXN overexpression via miR-218 suppression may promote tumor progression and metastasis and that PXN may predict survival and relapse in non-small cell lung cancer (NSCLC). Expression of miR-218 and PXN in 124 surgically resected lung tumors were evaluated by real-time PCR and immunohistochemical analysis. The prognostic value of miR-218 and PXN expression on overall survival (OS) and relapse-free survival (RFS) was analyzed by the Kaplan-Meier test and Cox regression analysis. miR-218 expression in lung tumors was negatively associated with PXN expression. Multivariate analyses showed that PXN and miR-218 might independently predict OS and RFS, respectively, in NSCLC. Moreover, patients with low miR-218 combined with PXN-positive had the worst OS and RFS among the 4 combinations. In a cell model, PXN was negatively regulated by miR-218 and cell proliferation, invasion, and soft agar colony formation were enhanced by PXN overexpression induced by miR-218 suppression. Taken together, our findings suggest that PXN overexpression induced by miR-218 suppression is an independent predictor of survival and relapse in NSCLC, highlighting PXN as a potential therapeutic target to improve clinical outcomes in this disease.

Expression and prognostic relevance of CD44v6 in stage I non-small cell lung carcinoma

PURPOSE

Expression of CD44 and its variants has been shown to be relevant to tumor progression in various human malignancies. We evaluated the expression of CD44v6 in the primary lesions of stage I non-small cell lung cancer (NSCLC) and correlated the expression level to its prognosis.

METHODS

The expression of CD44v6, measured by immunohistochemistry, was assessed in the tumor specimens from 190 patients with stage I NSCLC. Each slide was assigned a score: the average of the score of tumor cells staining multiplied by the score of staining intensity. And depending on the cut-off score based on receiver operating characteristic (ROC) curve analysis, the CD44v6 expression was categorized into high- and low-level groups, which were then correlated directly with the clinical outcomes.

RESULTS

The high expression of CD44v6 was detected more frequently in the squamous cell carcinoma (38 of 71 patients, 53.5%) than in the other types of carcinoma (p < 0.05). The Kaplan-Meier survival curves showed that high level expression of CD44v6 indicated a better post-operative survival (p = 0.006), especially for stage IB disease (p = 0.049) and squamous cell carcinoma (p = 0.029). The multivariate analysis also confirmed that the expression of CD44v6 was an independent prognostic indicator (p = 0.011).

CONCLUSIONS

CD44v6 might be correlated with histogenesis of NSCLC, and its decreased expression may be an adverse prognostic indicator for the patients with stage I NSCLC, especially for those with stage IB diseases. Patients of this subgroup might need adjuvant therapy additionally.

N-glycoprotein profiling of lung adenocarcinoma pleural effusions by shotgun proteomics

BACKGROUND

Malignant pleural effusion of advanced lung adenocarcinoma may be a valid source for detection of biomarkers, such as N-glycosylated proteins (N-GP), because tumor cells grow during weeks in this liquid. The authors aimed for creation of N-GP effusion profiles from routine cytology specimens to detect relevant biomarkers.

METHODS

Hundred microliters of malignant pleural effusions of 5 patients with lung adenocarcinoma and 5 nonmalignant controls were used for triplicate N-GP capture by solid-phase extraction. After trypsin digest and PNGase F release, a liquid chromatography separation connected online to a tandem mass spectrometer was performed by liquid chromatography/tandem mass spectrometry (LC/MS/MS).

RESULTS

In the total of 10 samples, 170 and 278 nonredundant proteins were detected with probabilities of >or=.9 and >or=.5, respectively. The specificity for the N-glycomotif was 88% at P >or= .9. Penetration into the moderate to low protein concentration range (microg-ng/mL) occurred, and several proteins associated with tumor progression or metastasis were identified, including CA-125, CD44, CD166, lysosome-associated membrane glycoprotein 2 (LAMP-2), multimerin 2, and periostin. MS identifications were correlated with the corresponding immunoreactivity in either effusion fluid or tumor tissue.

CONCLUSIONS

In conclusion, reduction of sample complexity by N-GP capturing allows detection of proteins in the mug to ng/mL range. Pleural effusion is a useful source for biomarker research in lung cancer.

Immunohistochemical markers of prognosis in non-small cell lung cancer: a review and proposal for a multiphase approach to marker evaluation

Characteristics of the tumour that affect and predict the survival outcome of patients with cancer are prognostic markers for cancer. In non-small cell lung carcinoma (NSCLC), stage is the main determinant of prognosis and the basis for deciding options for treatment. Patients with early-stage tumour are treated by complete surgical resection, which is curative in 40-70% of patients. That there are other factors important in determining the biology of these tumours, especially genes that have a role in metastasis, is indicated. Such factors could potentially be used to further classify patients into groups according to substages that may be treated differently. During the past decade, a large number of proteins that are putatively important in carcinogenesis and cancer biology have been studied for their prognostic value in NSCLC, but none of them have been proved to be sufficiently useful in clinical diagnosis. Several markers (epidermal growth factor receptor, human epidermal growth factor receptor 2, Ki-67, p53 and Bcl-2) have been studied exhaustively. Ki-67, p53 and Bcl-2 are suggested to be important but weak prognostic markers, by meta-analyses of the results. Cyclin E, vascular endothelial growth factor A, p16(INK4A), p27(kip1) and beta-catenin are promising candidates, but require further study in large randomised clinical trial samples by using standardised assays and scoring systems. Some issues and inconsistencies in the reported studies to date are highlighted and discussed. A guideline for a multi-phase approach for conducting future studies on prognostic immunohistochemistry markers is proposed here.

Immunohistochemical α- and β-catenin and E-cadherin expression and their clinicopathological significance in human lung adenocarcinoma

The E-cadherin/catenin complex (alpha-catenin, beta-catenin, and E-cadherin) plays a crucial role in cell-cell adhesion and tissue remodeling, and abnormalities in these molecules have been suggested to participate in the proliferation and invasive and metastatic potentials of several human carcinomas. However, in human lung adenocarcinomas, its importance has not yet been sufficiently investigated. We immunohistochemically examined the expressions of E-cadherin/catenin complex in 35 primary lung adenocarinomas, and evaluated their expressions in a semiquantitative manner. Correlations between these expression levels, MIB-1 and nuclear p53 indices, and clinicopathological factors were analyzed by subdividing the cases into high- and low-expression groups for each protein. The reduction in membranous E-cadherin/catenin complex expression correlated significantly with low-grade histological differentiation and with high MIB-1 index. Survival analyses were also performed to clarify which factors potentially affected the prognosis of lung adenocarcinoma patients. The low expression of beta-catenin and the high MIB-1 index had a significantly unfavorable influence on the patients' survival. Moreover, the immunohistochemical expression of beta-catenin by cancer cells and MIB-1 index are considered useful prognostic factors for lung adenocarcinoma.

Computed tomographic images reflect the biologic behavior of small lung adenocarcinoma: they correlate with cell proliferation, microvascularization, cell adhesion, degradation of extracellular matrix, and K-ras mutation

BACKGROUND

We previously reported that the computed tomographic M/L ratio (area of the tumor in the mediastinal computed tomographic image/area of the tumor in the lung computed tomographic image) of small peripheral lung adenocarcinoma is correlated with patient prognosis.

METHODS

Immunostaining for p53, bcl-2, Ki-67, vascular endothelial growth factor, CD34, matrix metalloproteinase 2, matrix metalloproteinase 9, tissue inhibitor of matrix metalloproteinase 2, and mutation of K-ras was assessed in 131 surgically resected, primary peripheral lung adenocarcinomas of 30 mm or less in maximum diameter to clarify the relationship between computed tomographic findings and biologic activities.

RESULTS

The numbers of patients with high labeling indexes of Ki-67 and high expression of vascular endothelial growth factor, CD34, matrix metalloproteinase 2, and matrix metalloproteinase 9 in the solid-type group (computed tomographic M/L ratio > or = 50%) were significantly higher than those in the faint density-type group (computed tomographic M/L ratio < 50%; P = .04 for Ki-67, P = .03 for vascular endothelial growth factor, P = .0009 for CD34, P = .001 for matrix metalloproteinase 2, and P = .00001 for matrix metalloproteinase 9). The number of patients with high levels of CD44v6 or tissue inhibitor of matrix metalloproteinase 2 staining in the faint density-type group was significantly higher than that in the solid-type group (P = .02 for CD44v6 and P = .01 for tissue inhibitor of matrix metalloproteinase 2). Independent variables capable of predicting computed tomographic M/L ratio included CD34, matrix metalloproteinase 2, matrix metalloproteinase 9, and tissue inhibitor of matrix metalloproteinase 2 (P = .0093, P = .0003, P = .0027, and P = .01, respectively; binary logistic regression analysis).

CONCLUSIONS

Our results suggest that the computed tomographic image of small lung adenocarcinoma is correlated with biologic activities and thus provides possible prognostic information.

The E-cadherin–β-catenin complex and its implication in lung cancer progression and prognosis

The E-cadherin–β−catenin complex plays a pivotal role in epithelial cell–cell adhesion and in the maintenance of differentiated adult epithelia. Perturbation of its expression or function is widely involved in tumor progression and metastasis. Recent years have seen a rapid expansion in the understanding of the biology and the clinical relevance of the E-cadherin adhesion complex in human lung cancer. During human lung cancer progression genomic, transcriptionnal and post-transcriptionnal alterations of the E-cadherin–β-catenin adhesion system are implicated and comprise deletion of the chromosomic region 3p21 that comprise the locus of the gene encoding β-catenin, transcriptionnal downregulation of E-cadherin, cytoplasmic redistribution, phosphorylation of both proteins and proteolysis of E-cadherin. E-cadherin-inactivating mutations and oncogenic-activating mutation of β-catenin are not reported.

[CA125 cytosolic levels in lung adenocarcinomas. New biological aspects]

INTRODUCTION

CA125 is a useful serum tumor marker in patients with non-mucinous ovarian cancer, but there may be high serum levels in other malignant tumors, among them the non-small cell lung cancers. We decided to study the cytosolic levels of CA125 in lung adenocarcinomas and compare them with pS2, CD44s, CD44v5 and CD44v6, all of them with biological interest in this subtype of lung carcinomas.

SUBJECTS AND METHODS

The study group included 55 patients (33 males) having lung adenocarcinomas. CA125 and cytostolic pS2 were measured by both IRMAS methods (CIS. Biointernational. France). The concentrations of CD44 standard (CD44s), CD44v5 and CD44v6 on cell surfaces were dosed by EIAS (Bender Diagnostics. Austria). Clinical stage, ploidy and S-phase cellular fraction were also taken into account.

RESULTS

In the 55 lung adenocarcinomas, cytosolic CA125 levels ranged between 1 and 225 U/mg prot. (median 80.5) and were higher (p:0.002) than those observed in 16 normal lung tissues from the same patients (r: 1-32.5; median 6.7 U/mg prot.). When the 25th (7.2 U/mg prot.) and 75th (320 U/mg prot.) percentiles were used as clinical cut-offs, we found that the cases with high antigenic levels showed a greater positivity for CD44v6 (p:0.002) and a reduced positivity for CD44 standard (p:0.053). Likewise, they showed a tendency towards being pS2 + (p:0.09) more frequently.

CONCLUSIONS

Our results lead us to draw the following conclusions: 1) Cytosolic CA125 levels in lung adenocarcinomas were higher than those observed in normal tissues from the same patients. 2) Lung adenocarcinomas with high cytosolic CA125 concentrations had a greater positivity for CD44v6, a reduced positivity for CD44s and were more frequently pS2 +. These associations support the usefulness of the cytosolic CA125 levels as an indicator of poor outcome in this subtype of lung carcinomas.

E-cadherin-beta-catenin adhesion complex in neuroendocrine tumors of the lung: a suggested role upon local invasion and metastasis

Dysfunction or loss of the intercellular adhesion complex E-cadherin-beta-catenin is frequent in non-small cell lung carcinomas in which E-cadherin and beta-catenin loss has been considered to be a molecular marker of tumor progression and poor prognosis. With an aim of evaluating the expression of the E-cadherin-beta-catenin complex and its prognostic role in neuroendocrine tumors (NET) of the lung, immunohistochemical analysis was performed in 102 NET, including 16 low-grade typical carcinoids, 8 intermediate-grade atypical carcinoids, 37 large-cell neuroendocrine carcinomas (LCNEC), and 41 small-cell lung carcinomas, both high-grade tumors. Impaired E-cadherin expression (loss or cytoplasmic delocalization) was observed in 80 (78%) of 102 samples, and impaired beta-catenin expression was noted in 74 (72%) of 102 cases. The impaired expression of E-cadherin and beta-catenin was observed with a higher frequency in high-grade tumors (87% and 83%, respectively) than in carcinoids (50% and 37%, respectively; P < 0.0001). Impaired expression of the E-cadherin and beta-catenin molecules also correlated with lymph node metastasis (P = 0.0001 and P = 0.0005, respectively) and with advanced stage disease (P < 0.0001 for both factors). Moreover, impaired E-cadherin expression directly correlated with an extensive disease in carcinoids and in LCNEC (P = 0.02 and P = 0.04, respectively) and with node metastasis in LCNEC (P = 0.01). Levels of E-cadherin and beta-catenin were correlated with each other, consistent with an internal regulatory loop. Our results indicate that down-regulation of the E-cadherin-beta-catenin complex plays a role in NET progression.

Proliferation, but not apoptosis, is associated with distinct beta-catenin expression patterns in non-small-cell lung carcinomas: relationship with adenomatous polyposis coli and G(1)-to S-phase cell-cycle regulators

beta-catenin (beta-cat) is a versatile component of homotypic cell adhesion and signaling. Its subcellular localization and cytoplasmic levels are tightly regulated by the adenomatous polyposis coli (APC) protein. Mutations in beta-cat (exon 3) or APC (MCR) result in beta-cat aberrant overexpression that is associated with its nuclear accumulation and improper gene activation. Data from experimental models have shown that beta-cat overexpression has a multitude of effects on cell-cycle behavior. In many of these aspects its function depends on major G(1) phase regulators. To the best of our knowledge, most of these issues have never been addressed concurrently in tumors. For this reason we investigated in a panel of 92 non-small-cell lung carcinomas, beta-cat and APC expression, and their relationship with cell-cycle kinetics (PI and AI) and ploidy status. Moreover, the above correlations were examined in relation to the main G(1)/S-phase checkpoint regulators. Four beta-cat immunohistochemical expression patterns [membranous (11.1%), membranous-cytoplasmic (54.3%), cytoplasmic (9.9%), cytoplasmic-nuclear (24.7%)] and three APC immunohistochemical expression patterns [cytoplasmic (37.7%), cytoplasmic-nuclear (58%), nuclear (4.3%)] were observed, which were further confirmed by Western blot analysis on subcellular fractions in representative samples. The frequent presence of beta-cat in the cytoplasm is an indication of aberrant expression, whereas membranous and nuclear localization were inversely related. Absence of mutations in beta-cat (exon 3) and APC (MCR) suggest that beta-cat destruction mechanisms may be functional. However, expression analysis revealed attenuated levels for APC, indicating a residual ability to degrade beta-cat. Decreased levels were associated with loss of heterozygosity at the APC region in 24% of the cases suggesting that additional silencing mechanisms may be involved. Interestingly, the 90-kd APC isoform associated with apoptosis, was found to be the predominant isoform in normal and cancerous lung tissues. The most important finding in our study, was the correlation of nuclear beta-cat immunohistochemical localization with increased proliferation, overexpression of E2F1 and MDM2, aberrant p53, and low expression of p27(KIP), providing for the first time in vivo evidence that beta-cat-associated proliferation correlates with release of E2F1 activity and loss of p53- and p27(KIP)-dependent cell-cycle checkpoints. Loss of these checkpoints is accompanied by low levels of APC, which possibly reflects a diminished ability to degrade beta-cat. Taken together our data indicate that cases with nuclear beta-cat immunohistochemical expression represent a subset of non-small-cell lung carcinomas that have gained an increased proliferation advantage in contrast to the other beta-cat immunohistochemical expression profiles.

Reduced expression of CD44 v3 and v6 is related to invasion in lung adenocarcinoma

We have previously reported that the histological pattern of invasion is correlated with the prognosis of surgically treated patients of lung adenocarcinoma. On the other hand, several clinicopathologic studies have shown that CD44 variant isoforms are associated with invasion and metastasis in human malignant tumors. The expression of CD44 variant isoforms v3 and v6 was analyzed in 93 Japanese lung adenocarcinoma patients by immunostaining to study the relationship between their expression and the invasion in lung adenocarcinoma. The specimens were histologically categorized into three groups. Both the invasive lesion and the noninvasive lesion were observed in 49 out of 93 cases (group I). Twenty cases were noninvasive carcinoma growing mainly in a lepidic pattern (group II). Twenty-three cases were invasive carcinoma which showed no frankly noninvasive lesion growing in a lepidic pattern (group III). The significant reduced expression of CD44 v3 and v6 was observed in the invasive lesion compared with the noninvasive lesion in adenocarcinoma of group I (P < 0.05). Although reduced expression of CD44 v3 and v6 was observed in the invasive carcinoma of group III compared with the noninvasive carcinoma of group II, it was not significant (P = 0.0693 for v3, P = 0.0827 for v6). The pattern of expression of CD44 v3 was significantly concordant with that of CD44 v6 (P < 0.0001). Our results suggest that reduced expression of CD44 v3 and v6 is associated with the invasion in the lung adenocarcinoma.

Putative role of 67 kDa elastin-laminin receptor in tumor invasion

Cellular regulatory mechanisms normally maintain a delicate balance between cell proliferation, quiescence and death. The imbalance between these functions resulting from molecular intracellular changes is a key factor in tumorigenesis. Tumor cells detaching from the primary tumor possess a propension for invasion and metastasis formation. These tumor cells can attach, migrate, proliferate and grow in host tissue. The surrounding extracellular matrix (ECM) modulates these functions. It is now widely accepted that cell-matrix interactions play an important role in these processes. Most investigators concentrated their attention on the role of integrins in the above processes. There are, however, only scant data on the role of elastin and its receptors in tumor invasion. Nevertheless, experimental evidence indicates that the 67 kDa elastin-laminin receptor (ELR) subunit plays an important role in tumor invasion by mediating essential tumor cell functions leading to metastases. In this review we will concentrate on the putative role of the 67 kDa ELR subunit in tumor invasion.