Desmoglein 3 as a prognostic factor in lung cancer

Multiplex Intraoperative Rapid Immunohistochemistry with Noncontact Antibody Mixing for Distinguishing the Histologic Phenotype of Lung Cancer

INTRODUCTION

Determining a surgical strategy for early-stage lung cancer requires an accurate histologic diagnosis. Immunohistochemistry (IHC) enables reliable diagnosis of histological types but requires more time and more tumor tissue slides than hematoxylin and eosin staining. We aimed to assess the clinical validity of a new rapid multiplex IHC technique utilizing alternating current (AC) mixing for intraoperative lung cancer diagnosis.

METHODS

Forty-three patients who underwent radical resection of lung cancers were enrolled in a retrospective observational study. Frozen sections were prepared from lung tumor samples, and rapid IHC employing AC mixing was implemented alongside a multiplex IHC protocol targeting thyroid transcription factor-1 + cytokeratin 5, desmoglein 3 + Napsin A, and p63 + tripartite motif containing 29. We then evaluated the concordance between intraoperative diagnoses derived from rapid multiplex IHC and final pathology.

RESULTS

The concordance rate between the pathological diagnosis made with added rapid multiplex IHC and the final pathology was 93.0% (Cohen's 𝜅 coefficient = 0.860 and 95% CI: 0.727-0.993). When considering only adenocarcinoma and squamous cell carcinoma, the diagnoses were in agreement for all cases.

CONCLUSIONS

We suggest rapid multiplex IHC as a promising tool for determining surgical strategies for lung tumors.

Novel nanoparticle AuNCs conjugated with Desmoglein-3 antibody for FL/CT dual-mode targeted imaging and precise treatment of lung squamous cell carcinoma

Due to lack of effective, early and non-invasive diagnostic as well as treatment tools, the surgical treatment opportunities for lung squamous cell carcinoma (SCC) are limited, resulting in high mortality rates. Therefore, the combination of targeted recognition and precise treatment of lung SCC is of great significance. In this study, a multifunctional nanoparticle is designed and synthesized, which specifically identifies lung SCC cells for target imaging and therapy. Desmoglein-3 (Dsg-3), a transmembrane glycoprotein found in desmosomes, is highly expressed in lung SCC cells. Gold nanoclusters (AuNCs) conjugated with Dsg-3 antibodies to form Au-Dsg-3 through coupling reaction. The results showed that the fluorescence imaging (FI) intensity and computed tomography (CT) signal of Au-Dsg-3 significantly increased within 6 h in vitro and in vivo, achieving dual-modal imaging to detect lung SCC effectively. Besides, Au-Dsg-3 even integrates targeted photothermal therapy (PTT) characteristics in a single nanoparticle. When exposed to near-infrared radiation (NIR), the temperature of the tumor site increased rapidly and reached a high temperature of 53.3 °C after 600 s, causing tumor ablation and growth inhibition. In summary, Au-Dsg-3 provides a key platform for targeted biological imaging and collaborative PTT, which demonstrates good performance on lung SCC.

Deep-Learning-Based Cancer Profiles Classification Using Gene Expression Data Profile

The quantity of data required to give a valid analysis grows exponentially as machine learning dimensionality increases. In a single experiment, microarrays or gene expression profiling assesses and determines gene expression levels and patterns in various cell types or tissues. The advent of DNA microarray technology has enabled simultaneous intensive care of hundreds of gene expressions on a single chip, advancing cancer categorization. The most challenging aspect of categorization is working out many information points from many sources. The proposed approach uses microarray data to train deep learning algorithms on extracted features and then uses the Latent Feature Selection Technique to reduce classification time and increase accuracy. The feature-selection-based techniques will pick the important genes before classifying microarray data for cancer prediction and diagnosis. These methods improve classification accuracy by removing duplicate and superfluous information. The Artificial Bee Colony (ABC) technique of feature selection was proposed in this research using bone marrow PC gene expression data. The ABC algorithm, based on swarm intelligence, has been proposed for gene identification. The ABC has been used here for feature selection that generates a subset of features and every feature produced by the spectators, making this a wrapper-based feature selection system. This method's main goal is to choose the fewest genes that are critical to PC performance while also increasing prediction accuracy. Convolutional Neural Networks were used to classify tumors without labelling them. Lung, kidney, and brain cancer datasets were used in the procedure's training and testing stages. Using the cross-validation technique of k-fold methodology, the Convolutional Neural Network has an accuracy rate of 96.43%. The suggested research includes techniques for preprocessing and modifying gene expression data to enhance future cancer detection accuracy.

Characterization of Desmoglein 3 (DSG3) as a Sensitive and Specific Marker for Esophageal Squamous Cell Carcinoma

Although P40 and P63 are both sensitive and specific for routine esophageal squamous cell carcinoma (SCC) diagnosis, we recently showed that P40 and P63 immunoreactivities were significantly lower in well-differentiated SCC than those in higher grade tumors. Therefore, a novel esophageal SCC marker, ideally performing better in well-differentiated SCC, is still needed. We characterized desmoglein 3 (DSG3) immunohistochemistry in esophageal SCC, esophageal adenocarcinoma, small-cell lung carcinoma, and large B-cell lymphoma, alongside P40 and CK5/6. The World Health Organization classification was used to grade tumors as well-differentiated (WD), moderately differentiated (MD), or poorly differentiated (PD). There were 20 WD, 26 MD, and 17 PD components among 39 esophageal SCC cases. All esophageal SCC components showed significant DSG3 immunoreactivity (mean, 80%; range, 30%–100%), and the proportions of DSG3 immunoreactive cells were higher in the WD and MD components than in the PD components. No esophageal adenocarcinoma cases showed more than 10% DSG3 immunoreactivity with only weak cytoplasmic staining. With a 5% immunoreactivity cutoff, DSG3 positivity was 100% in all 63 SCC components, 18% in adenocarcinoma cases, and 0% in small-cell lung carcinoma or large B-cell lymphoma cases. The overall DSG3 specificity was 94%. To the best of our knowledge, this is the first study to characterize DSG3 as a sensitive and specific marker for esophageal SCC.

Tissue-specific effects of an anti-desmoglein-3 ADCC antibody due to expression of the target antigen and physiological characteristics of the mouse vagina

Desmoglein-3 (DSG3) is a potential target of cytotoxic antibody therapy for squamous cell carcinomas but is also expressed in various normal squamous epithelia. We obtained information about DSG3 distribution in mouse tissues by immunohistochemistry and conducted an intravenous multiple-dose study in mouse to estimate the toxic potential of anti-DSG3 therapy. DSG3 was expressed in the squamous epithelium of several organs including the skin, esophagus, tongue, forestomach, eye, and vagina. It was expressed at all estrous cycles of the vagina with changes in distribution patterns along with the structural changes in each cycle, and expression was reduced in ovariectomized (OVX) mice. On the administration of the antibody, there was disarrangement of the vaginal mucosal epithelium with formation of miroabscess, increased granulocyte infiltration, and single cell necrosis. Despite similar expression levels of DSG3 in other tissues, histopathological changes were limited to the vagina. The severity of the changes was reduced by ovariectomy. From these findings, the lesions were thought to be related to the drastic change in the histological structure of the vaginal mucosa accompanying the estrous cycle. Thus, we have shown that the changing expression of target antigen distribution and its relationship with physiological changes in tissue structure are important features for estimating the toxic potential of cytotoxic antibody therapy.

Cell-surface marker discovery for lung cancer

Lung cancer is the leading cause of cancer deaths in the United States. Novel lung cancer targeted therapeutic and molecular imaging agents are needed to improve outcomes and enable personalized care. Since these agents typically cannot cross the plasma membrane while carrying cytotoxic payload or imaging contrast, discovery of cell-surface targets is a necessary initial step. Herein, we report the discovery and characterization of lung cancer cell-surface markers for use in development of targeted agents. To identify putative cell-surface markers, existing microarray gene expression data from patient specimens were analyzed to select markers with differential expression in lung cancer compared to normal lung. Greater than 200 putative cell-surface markers were identified as being overexpressed in lung cancers. Ten cell-surface markers (CA9, CA12, CXorf61, DSG3, FAT2, GPR87, KISS1R, LYPD3, SLC7A11 and TMPRSS4) were selected based on differential mRNA expression in lung tumors vs. non-neoplastic lung samples and other normal tissues, and other considerations involving known biology and targeting moieties. Protein expression was confirmed by immunohistochemistry (IHC) staining and scoring of patient tumor and normal tissue samples. As further validation, marker expression was determined in lung cancer cell lines using microarray data and Kaplan–Meier survival analyses were performed for each of the markers using patient clinical data. High expression for six of the markers (CA9, CA12, CXorf61, GPR87, LYPD3, and SLC7A11) was significantly associated with worse survival. These markers should be useful for the development of novel targeted imaging probes or therapeutics for use in personalized care of lung cancer patients.

Podoplanin is an important stromal prognostic marker in perihilar cholangiocarcinoma

Cancer-associated fibroblasts (CAFs) exhibit various phenotypes and serve an important role in tumor progression. However, research on podoplanin expression in CAFs is limited, and its role in the cholangiocarcinoma microenvironment remains unclear. The present study analyzed the clinical and pathological records of 42 patients diagnosed with perihilar cholangiocarcinoma (pCCA) in The Affiliated Drum Tower Hospital of Nanjing University Medical School (Nanjing, China). Immunohistochemical staining was performed to evaluate the expression of podoplanin in CAFs in order to determine its association with clinicopathological parameters and survival rate. Podoplanin expression in the CAFs was associated with the tumor-node-metastasis staging system, and lymph node metastasis in pCCA. Tumor tissue demonstrated an increase in lymphatic vessel density (LVD) compared with para-tumor tissue. Podoplanin expression in CAFs was associated with LVD in tumor and para-tumor tissues. To examine the effect of podoplanin expression in CAFs on tumor progression, CAFs were isolated from tumor xenografts. Following transfection with an expression plasmid encoding podoplanin, the migratory ability of CAFs was significantly increased. Therefore, CAF-associated podoplanin expression in pCCA may serve as a potential biomarker to evaluate prognosis and provide a valuable target for anticancer therapy.

Molecular strategies in the management of bronchopulmonary and thymic neuroendocrine neoplasms

Thoracic NETs [bronchopulmonary NETs (BPNETs) and thymic NETs (TNET)] share a common anatomic primary location, likely a common cell of origin, the "Kulchitsky cell" and presumably, a common etiopathogenesis. Although they are similarly grouped into well-differentiated [typical carcinoids (TC) and atypical carcinoids (AC)] and poorly differentiated neoplasms and both express somatostatin receptors, they exhibit a wide variation in clinical behavior. TNETs are more aggressive, are frequently metastatic, and have a lower 5-year survival rate (~50% vs. ~80%) than BPNETs. They are typically symptomatic, most often secreting ACTH (40% of tumors) but both tumor groups share secretion of common biomarkers including chromogranin A and 5-HIAA. Consistently effective and accurate circulating biomarkers are, however, currently unavailable. Surgery is the primary therapeutic tool for both BPNET and TNETs but there remains little consensus about later interventions e.g., targeted therapy, or how these can be monitored. Genetic analyses have identified different topographies (e.g., significant alterations in chromatin and epigenetic remodeling in BPNETs versus frequent chromosomal abnormalities in TNETs) but there is an absence of clinically actionable mutations in both tumor groups. Liquid biopsies, tools that can measure neoplastic signatures in peripheral blood, can potentially be leveraged to detect disease early i.e., recurrence, predict tumors that may respond to specific therapies and serve as real-time monitors for treatment responses. Recent studies have identified that mRNA transcript analysis in blood effectively identifies both BPNET and TNETs. The clinical utility of this gene expression assay includes use as a diagnostic, confirmation of completeness of surgical resection and use as a molecular management tool to monitor efficacy of PRRT and other therapeutic strategies.

Desmoglein-2 is overexpressed in non-small cell lung cancer tissues and its knockdown suppresses NSCLC growth by regulation of p27 and CDK2

PURPOSE

Desmoglein-2 (Dsg2) is a cell adhesion protein of the cadherin superfamily. Altered Dsg2 expression is associated with tumorigenesis. This study determined Dsg2 expression in non-small cell lung cancer (NSCLC) tissue specimens for association with clinicopathological and survival data and then assessed the effect of Dsg2 knockdown on regulation of NSCLC cell malignant behaviors in vitro and in nude mouse xenografts.

METHODS

qRT-PCR and Western blot were used to detect Dsg2 expression in 28 paired NSCLC and normal tissue samples. Immunohistochemistry was used to detect Dsg2 expression in 70 cases of paraffin-embedded NSCLC tissues. NSCLC A549, H1703, and H1299 cells were cultured with Dsg2 knockdown performed using Dsg2 siRNA. Cell viability, cell cycle, apoptosis, and colony formation were assessed. siRNA-transfected A549 cells were also used to generate tumor xenografts in nude mice.

RESULTS

Both Dsg2 mRNA and protein were highly expressed in NSCLC tissues and associated with NSCLC size, but not with overall survival of patients. Moreover, knockdown of Dsg2 expression reduced NSCLC cell proliferation and arrested them at the G1 phase of the cell cycle, but did not significantly affect NSCLC cell apoptosis. Dsg2 knockdown downregulated cyclin-dependent kinase 2 expression and upregulated p27 expression. Nude mouse xenograft assays showed that Dsg2 knockdown inhibited NSCLC xenograft growth in vivo.

CONCLUSION

This study revealed the importance of Dsg2 in suppression of NSCLC development and progression. Further studies will explore whether restoration of Dsg2 expression is a novel strategy in control of NSCLC.

New immunohistochemical markers in the differential diagnosisof nonsmall cell lung carcinoma

BACKGROUND/AIM

The aim of this study was to investigate Napsin-A, NTRK-1, NTRK-2, Desmoglein-3, and Desmocollin-3 in the differential diagnosis and prognosis of nonsmall cell lung cancer.

MATERIALS AND METHODS

The expression of Napsin-A, NTRK-1, NTRK-2, and Desmoglein-3 was examined by immunohistochemistry in 50 squamous cell carcinomas and 50 adenocarcinomas. Desmocollin-3 was investigated in 29 squamous cell carcinoma and 29 adenocarcinoma cases. Associations between expression profiles of Napsin-A, NTRK-1, NTRK-2, Desmoglein-3, and Desmocollin-3 in lung cancers and clinicopathological variables were analyzed.

RESULTS

Napsin-A staining was statistically significant in detecting adenocarcinomas versus squamous cell carcinomas. The sensitivity of Napsin-A for adenocarcinomas was 96% and the specificity was 100%. NTRK-2 and Desmocollin-3 staining were statistically significant in detecting squamous cell carcinomas versus adenocarcinomas. Desmoglein-3, Napsin-A, and NTRK-2 had no effect on survival. Disease-free survival time was significantly shorter in cases that were moderately positive with NTRK-1.

CONCLUSION

Our data suggest that Napsin-A, NTRK-2, and Desmocollin-3 are useful markers in the differentiation of nonsmall cell lung cancer.

Desmogleins as prognostic biomarkers in resected pancreatic ductal adenocarcinoma

Background:

Frequent disease relapse and a lack of effective therapies result in a very poor outcome in pancreatic ductal adenocarcinoma (PDAC) patients. Thus, identification of prognostic biomarkers and possible therapeutic targets is essential. Besides their function in cell–cell adhesion, desmogleins may play a role in tumour progression and invasion that has not been investigated in PDAC to date. This study evaluated desmoglein expression as a biomarker in PDAC.

Methods:

Using immunohistochemistry, we examined desmoglein 1 (DSG1), desmoglein 2 (DSG2) and desmoglein 3 (DSG3) expression in the tumour tissue of 165 resected PDAC cases. Expression levels were correlated to the patients' clinicopathological parameters and postoperative survival times. We confirmed these results in two independent gene expression data sets.

Results:

A total of 36% of the tumours showed high DSG3 expression that correlated significantly with shorter patient survival (P=0.011) and poor tumour differentiation (P<0.001), whereas no such association was detected for DSG1 or DSG2. In RNA-Seq data and in microarray expression data, high DSG3 expression correlated significantly with poor survival (P=0.000356 and P=0.00499).

Conclusions:

We identify DSG3 as a negative prognostic biomarker in resected PDAC, as high DSG3 expression is associated with poor overall survival and poor tumour-specific survival. These findings suggest DSG3 and its downstream signalling pathways as possible therapeutic targets in DSG3-expressing PDAC.

Desmoglein 3: a help or a hindrance in cancer progression?

Desmoglein 3 is one of seven desmosomal cadherins that mediate cell-cell adhesion in desmosomes. Desmosomes are the intercellular junctional complexes that anchor the intermediate filaments of adjacent cells and confer strong cell adhesion thus are essential in the maintenance of tissue architecture and structural integrity. Like adherens junctions, desmosomes function as tumour suppressors and are down regulated in the process of epithelial-mesenchymal transition and in tumour cell invasion and metastasis. However, recently several studies have shown that various desmosomal components, including desmoglein 3, are up-regulated in cancer with increased levels of expression correlating with the clinical stage of malignancy, implicating their potentiality to serve as a diagnostic and prognostic marker. Furthermore, in vitro studies have demonstrated that overexpression of desmoglein 3 in cancer cell lines activates several signal pathways that have an impact on cell morphology, adhesion and locomotion. These additional signalling roles of desmoglein 3 may not be associated to its adhesive function in desmosomes but rather function outside of the junctions, acting as a key regulator in the control of actin based cellular processes. This review will discuss recent advances which support the role of desmoglein 3 in cancer progression.

Expression of desmogleins 1-3 and their clinical impacts on human lung cancer

AIMS

Desmogleins (DSGs) are components of the cell-cell connecting desmosomes. Desmosomal proteins have been found dysregulated in various cancers. Here we studied the role of DSGs in human lung cancer.

METHODS

Expression of DSG1-3 mRNA in lung cancer cell lines and human bronchial epithelial cells (HBEC) was examined by real time RT-PCR. Methylation status of DSG1-2 was evaluated by demethylation test and bisulfite sequencing (BS). Moreover, DSG1-3 protein expression was analysed in 112 primary lung tumor samples by immunohistochemistry (IHC) on tissue microarrays.

RESULTS

It turned out that DSG1-3 was downregulated in most of the lung cancer cell lines. Reexpression of DSG2 and DSG3 was found in several cancer cell lines after demethylation treatment with 5-aza-2'-deoxycytidine (DAC), a DNA methyltransferase inhibitor. Complete or partial methylation of DSG2 promoter region was detected in 5 out of 6 cancer cell lines by BS. In primary lung tumors, higher protein expression of DSG2 and DSG3 correlated to the diagnosis of squamous cell lung carcinoma (SCC) (P=0.009 and P<0.001, respectively), additionally, a lower expression of DSG3 was significantly linked to higher tumor grade (P=0.012).

CONCLUSIONS

Our data suggest that downregulation of DSG2 and DSG3 could be partially explained by DNA methylation. DSG2 and DSG3 might be potential diagnostic markers for SCC, and DSG3 could be a potential differentiation marker for lung cancer.

Altered expression and localization of desmoglein 3 in esophageal squamous cell carcinoma

Desmoglein 3 (DSG3), a transmembrane cadherin of the desmosomal cell-cell adhesion structure, plays vital roles in the maintenance of normal epithelial tissue architecture. Reports implicating a role for DSG3 expression in cancer are few and contradictory. In this study, immunohistochemical staining was employed to investigate DSG3 expression and subcellular localization in esophageal squamous cell carcinoma (ESCC), and to correlate changes with clinical characteristics. Results indicate that in normal squamous cell epithelia, strong DSG3 immunoreactivity was observed in the Stratum spinosum, and localization occurred only at the cell membrane. In ESCC, DSG3 immunoreactivity displayed an abnormal cytoplasmic localization that was correlated with cell differentiation (P=0.018). Most strikingly, in 74.1% of the tumors, DSG3 expression was up-regulated and correlated with regional lymph node metastasis (P=0.036). Moreover, in patients without lymph node metastasis, cytoplasmic localization of DSG3 correlated with poor prognosis (P=0.044). These results suggest that DSG3 is involved in the development of ESCC and imply that DSG3 overexpression is likely to be an essential contributor to the aggressive features of esophageal cancer.

Management of a pemphigus with IgA and IgG antibodies and coexistent lung cancer

Immunoglobulin A (IgA) pemphigus is a clinically distinct variant of pemphigus characterized by intercellular IgA deposition in the epidermis. Recently, an IgA/Immunoglobulin G (IgG) subset of pemphigus with IgA and IgG anti-keratinocyte cell surface antibodies has been described. Both IgA and IgA/IgG pemphigus have been associated with internal malignancies. Above all, monoclonal IgA gammopathy in patients with IgA pemphigus has been reported, and lung cancers in association with IgA/IgG pemphigus have been described. IgA pemphigus can be successfully treated with dapsone, whereas therapeutic management of IgG/IgA pemphigus is not well established yet. We report a rare case of a patient, who developed atypical pemphigus with both IgA and IgG autoantibodies and an underlying lung cancer, successfully treated with corticosteroids and dapsone.

Prognostic significance of desmoglein 2 and desmoglein 3 in esophageal squamous cell carcinoma

OBJECTIVE

Desmogleins (DSGs) are major members among the desmosomal cadherins critically involved in cell-cell adhesion and the maintenance of normal tissue architecture in epithelia. Reports exploring links of DSG family member expression with cancers are few and vary. The aim of this study was to investigate the ratio of DSG2 and DSG3 mRNA expression in esophageal squamous cell carcinoma (ESCC) tissue to normal tissue (T/N ratio) and evaluate correlations with clinical parameters.

METHODS

The mRNA expression of DSGs, as well as γ-catenin and desmoplakin, was detected by real-time quantitative RT-PCR in 85 cases of ESCC tissue specimens.

RESULTS

The expression level of DSG3 mRNA was significantly higher than that of DSG2 in ESCC specimens (p = 0.000). DSG3 mRNA expression highly correlated with histological grade (p = 0.009), whereas that of DSG2 did not significantly relate to any clinicopathologic parameter. Kaplan-Meier survival analysis showed that only DSG3 expression had an impact on the survival curve, with negative DSG3 expression indicating worse survival (p = 0.038). Multivariate Cox regression analysis demonstrated DSG3 to be an independent prognostic factor for survival. Furthermore, correlation analysis demonstrated the mRNA level of DSG3 to highly correlate with those of γ-catenin and desmoplakin in ESCC samples (p=0.000), implying that the expression of desmosomal components might be regulated by the same upstream regulatory molecules.

CONCLUSIONS

Our findings suggest that DSG3 may be involved in the progression of ESCC and serve as a prognostic marker, while expression of DSG2 cannot be used as a predictor of ESCC patient outcome.

Cellular localization of protein arginine methyltransferase-5 correlates with grade of lung tumors

Background

Protein arginine methyltransferase-5 (PRMT5) is a chromatin-modifying enzyme capable of methylating histone and non-histone proteins, and is involved in a wide range of cellular processes that range from transcriptional regulation to organelle biosynthesis. As such, its overexpression has been linked to tumor suppressor gene silencing, enhanced tumor cell growth and survival.

Material and methods

Quantitative real-time polymerase chain reaction, Western immunoblot and immunohistochemistry were used to characterize PRMT5 expression in lung cancer cell lines and human tumors. Clinicopathological findings of tissue microarray based samples from 229 patients with non-small cell lung carcinomas (NSCLC) and 133 cases with pulmonary neuroendocrine tumors (NET) were analyzed with regard to nuclear and cytoplasmic PRMT5 expression.

Results

There was statistically significant difference in PRMT5 messenger RNA expression between tumors and nonneoplastic lung tissues. Immunoblot experiments showed abundant expression of PRMT5 and its symmetric methylation mark H4R3 in lung carcinoma but not in non-neoplastic human pulmonary alveolar and bronchial epithelial cell lines. More than two thirds of lung tumors expressed PRMT5. High levels of cytoplasmic PRMT5 were detected in 20.5% of NSCLC and in 16.5% of NET; high levels of nuclear PRMT5 were detected in 38.0% of NSCLC and 24.0% of NET. Cytoplasmic PRMT5 was associated with high grade in both NSCLC and pulmonary NET while nuclear PRMT5 was more frequent in carcinoid tumors (p < 0.05).

Conclusion

The observed findings support the role of PRMT5 in lung tumorigenesis and reflect its functional dichotomy in cellular compartments.

Virtual slide

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1611895162102528

Application of a new technique, spiral tissue microarrays constructed using needle biopsy specimens, to prostate cancer research

Tissue microarrays were constructed using prostate needle biopsy specimens obtained from 58 patients who underwent radical prostatectomy for localized or locally advanced prostate cancer (PC). We used the spiral array (SA) technique, a novel approach for tissue array construction in a spiral form, which has advantages over small needle biopsy specimens. Roll-shaped tissue pieces produced by slicing a prostate biopsy tissue block and trimming the cancer segment were used to obtain a tissue array block. Cancer segments measuring >3 mm were incorporated into the tissue arrays. Cancer fragments (n=253) were obtained from formalin-fixed, paraffin-embedded needle biopsy specimens. The median number of cancer fragments per patient was four (1-8, min-max). On SA, the median number of confirmed cancer fragments per patient was four (1-7) and 224 cancer fragments (88.5%) were confirmed histologically. Each core of reeled tissue contained at least one cancer fragment. The expressions of multiple prognostic molecular markers for PC (Ki-67, p53 and bcl-2) were immunohistochemically measured using the SA. The Ki-67 and bcl-2 expressions were significantly associated with the Gleason score (GS). A univariate analysis identified Ki-67, bcl-2 and GS as significant predictors of cancer-specific survival, p53 and bcl-2 as significant predictors of overall survival and Ki-67, adjuvant androgen deprivation and GS as significant predictors of biochemical progression. In a multivariate analysis, p53 was independently associated with overall survival, while adjuvant androgen deprivation and GS were associated with biochemical progression. These results indicate that SA has potential as a new tool for translational research on PC.

DSG3 facilitates cancer cell growth and invasion through the DSG3-plakoglobin-TCF/LEF-Myc/cyclin D1/MMP signaling pathway

Desmoglein 3 (DSG3) is a component of the desmosome, which confers strong cell-cell adhesion. Previously, an oncogenic function of DSG3 has been found in head neck cancer (HNC). Here, we investigated how this molecule contributes to the malignant phenotype. Because DSG3 is associated with plakoglobin, we examined whether these phenotypic alterations were mediated through the plakoglobin molecule. Immunoprecipitation and immunofluorescence staining revealed that DSG3 silencing disrupted its interaction with plakoglobin and induced plakoglobin translocation from the cytoplasm to the nucleus. Knockdown of DSG3 significantly increased the interaction of plakoglobin with the transcriptional factor TCF and suppressed the TCF/LEF transcriptional activity. These effects further conferred to reduced expression of the TCF/LEF downstream target genes, including c-myc, cyclin D1, and MMP-7. Functional analyses showed that DSG3 silencing reduced cell growth and arrested cells at G0/G1 phase. Besides, cell migration and invasion abilities were also decreased. These cellular results were confirmed using tumor xenografts in mice, as DSG3 silencing led to the suppressed tumor growth, plakoglobin translocation and reduced expression of TCF/LEF target genes in tumors. Therefore, our study shows that the desmosomal protein DSG3 additionally functions to regulate malignant phenotypes via nuclear signaling. In conclusion, we found that DSG3 functions as an oncogene and facilitates cancer growth and invasion in HNC cells through the DSG3-plakoglobin-TCF/LEF pathway.

Spiral array: a new high-throughput technology covers tissue heterogeneity

CONTEXT

Tissue array is a well-established technique that connects basic research with clinical applications and allows for the validation of many pathobiologic events from gene expression dysregulation to genomic aberrations. However, conventional tissue array has several limitations such as poor representation of tissue heterogeneity, destruction of donor tissue blocks due to coring, and usage of particular specimens that have limited evaluable material (tissue from thin specimens or needle biopsies).

OBJECTIVE

To show the noninferiority and superiority of the new technique named Spiral Array-which allows for improved representation of the donor tissue while keeping the architectural details of the donor block intact-to that of the conventional tissue array. We compared the morphologic features of both methods.

DESIGN

We created both Spiral Array and conventional tissue array for 25 lung adenocarcinomas and 50 multiple tumors of various organs. The degree of coverage of tissue heterogeneity was examined by observing the range of the staining intensity differences in immunohistochemistry, using cytokeratin 7 and epidermal growth factor receptor (EGFR); the degree of morphologic preservation was tested by level of accurate prediction among 3 pathologists of the histopathologic diagnosis and organ type.

RESULTS

The Spiral Array showed better representations of the range of staining intensity for EGFR (P  =  .01). The level of accuracy for predicting organ type was significantly higher in Spiral Array than conventional tissue array (P  =  .047), whereas it was not significantly different between the 2 techniques for the histologic diagnosis.

CONCLUSION

Our data indicate that Spiral Array has benefits for covering tissue heterogeneity and preserving better morphology.

Tissue-preserving antibody cocktails to differentiate primary squamous cell carcinoma, adenocarcinoma, and small cell carcinoma of lung

CONTEXT

With the availability of cell type-specific therapies, differentiating primary lung squamous cell carcinomas (SCCs) and adenocarcinomas (ACAs) has become important. The limitations of small sample size and the need to conserve tissue for additional molecular studies necessitate the use of sensitive and specific marker panels on a single slide.

OBJECTIVE

To distinguish SCC from ACA and small cell carcinoma (SmCC) of lung using 2 novel tissue-conserving cocktails.

DESIGN

We compared two antibody cocktails, desmoglein 3 + cytokeratin 5/napsin A and p40/thyroid transcription factor 1 (Biocare Medical, Concord, California) in diagnosing SCC and ACA of the lung on tissue microarray, cytology, and surgical specimens. Both lung and nonlung tissue were evaluated on an 1150-core tissue microarray that contained 200 lung cancers. A microarray of 35 SmCCs and 5 small cell SCCs was also evaluated.

RESULTS

A cocktail of desmoglein 3 + cytokeratin 5/napsin A provided diagnostic accuracy in lung cancers with a sensitivity and specificity of 100% in SCCs and a sensitivity of 86% and a specificity of 100% in ACAs. A p40/thyroid transcription factor 1 cocktail showed p40 to have a specificity of 92% and a sensitivity of 93% in SCCs, whereas thyroid transcription factor 1 had a specificity of 100% and a sensitivity of 77% in ACAs. Cell blocks of fine-needle aspiration cytology compared with corresponding surgical (n = 20) specimens displayed similar findings. The p40 was useful in differentiating bladder from prostate carcinoma with 88% sensitivity. Isolated carcinomas from nonlung tissues were desmoglein 3 + cytokeratin 5 positive. Napsin A was positive in 22% of renal tumors as previously observed. Both cocktails were excellent in differentiating SmCCs and small cell SCCs because none of the SmCCs stained with p40.

CONCLUSIONS

Both antibody cocktails are excellent in differentiating primary lung ACA from SCC, as well as excluding SmCC and ACAs from all other sites on small specimens. A cocktail of desmoglein 3 + cytokeratin 5/napsin A is slightly superior compared with p40/thyroid transcription factor 1 cocktail.

A 6-antibody panel for the classification of lung adenocarcinoma versus squamous cell carcinoma

Non-small cell lung cancer can be classified into several histologic subtypes, most commonly lung adenocarcinoma (LADC) or squamous cell carcinoma (SqCC). With the introduction of targeted therapies that can result in dramatically different outcomes based on subtype, the importance of accurate classification has been amplified. Six antibodies (Napsin A, Desmoglein 3, TTF-1, CK5, p63, and tripartite motif-containing 29) were selected for evaluation on cases of LADC of lung SqCC. Guided by the sensitivities and specificities determined for individual antibodies, a protocol was developed using a sequential series of 2-antibody cocktails that resulted in the classification of 93% of cases with 100% specificity. Importantly, the initial step in this method, a napsin A+Desmoglein 3 antibody cocktail classified >85% of cases, resulting in <15% of cases requiring further evaluation beyond a single test. Two new antibodies specifically developed and optimized for the diagnosis of LADC and lung SqCC, a rabbit polyclonal Napsin A and a mouse monoclonal Desmoglein 3 [BC11], were the key elements of the antibody panel. Most importantly, the described protocol uses routine interpretation methods and an uncomplicated algorithm for classification. Given the increased difficulty of diagnosing poorly differentiated tumors, the ability of this 6-antibody panel to classify 96% and 87% of moderately and poorly differentiated cases, respectively, is of particular value, especially when limited tissue for molecular testing is an issue.

Advances in fine needle aspiration cytology for the diagnosis of pulmonary carcinoma

New developments in the field of thoracic oncology have challenged the way pathologists approach the diagnosis of pulmonary carcinoma. Nonsmall cell carcinoma is no longer an adequate diagnostic category. Pathologists are required to further classify tumors into adenocarcinoma and squamous cell carcinoma since specific therapies are now recommended depending on the histological tumor type. This change occurred following the discovery of specific molecular alterations that predict response to certain drugs and now molecular testing of tumor cells is often requested to direct therapy. The vast majority of lung cancer is diagnosed in advanced clinical stages, where cytologic or small biopsy material is the only form of tissue diagnosis, thus placing cytology, especially fine needle aspiration biopsy in the front line for management of patients with lung cancer. In this paper we will review the current concepts in the suitability and accuracy of fine needle aspiration biopsy, including diagnosis, classification, prognostic markers, and use of ancillary techniques.

DSC3 expression is regulated by p53, and methylation of DSC3 DNA is a prognostic marker in human colorectal cancer

Background:

Desmocollin 3 (DSC3), a member of the cadherin superfamily and integral component of desmosomes, is involved in carcinogenesis. However, the role of DSC3 in colorectal cancer (CRC) has not yet been established.

Methods:

Desmocollin 3 expression in CRC cell lines was analysed by RT–PCR and western blotting. Methylation status of DSC3 was examined by demethylation tests, methylation-specific PCR, and bisulphite sequencing (BS). The regulatory role of p53 was investigated by transfection.

Results:

Desmocollin 3 was downregulated in CRC cells at mRNA and protein levels. Desmocollin 3 expression was restored in five out of seven cell lines after 5-aza-2′-deoxycytidine (DAC) treatment. A heterogeneous methylation pattern was detected by BS in promoter region and exon 1 of DSC3. Methylation of DSC3 genomic sequences was found in 41% (41 out of 99) of primary CRC, being associated with poor prognosis (P=0.002). Transfection of p53 alone or in combination of DAC increased the DSC3 expression. Similarly, treatment with p53 inducer adriamycin alone or in combination with DAC enhanced DSC3 expression.

Conclusions:

DNA methylation contributes to downregulation of DSC3 in CRC cell lines. Methylation status of DSC3 DNA is a prognostic marker for CRC. P53 appears to have an important role in regulating DSC3 expression.

Desmoglein 3, via an interaction with E-cadherin, is associated with activation of Src

BACKGROUND

Desmoglein 3 (Dsg3), a desmosomal adhesion protein, is expressed in basal and immediate suprabasal layers of skin and across the entire stratified squamous epithelium of oral mucosa. However, increasing evidence suggests that the role of Dsg3 may involve more than just cell-cell adhesion.

METHODOLOGY/PRINCIPAL FINDINGS

To determine possible additional roles of Dsg3 during epithelial cell adhesion we used overexpression of full-length human Dsg3 cDNA, and RNAi-mediated knockdown of this molecule in various epithelial cell types. Overexpression of Dsg3 resulted in a reduced level of E-cadherin but a colocalisation with the E-cadherin-catenin complex of the adherens junctions. Concomitantly these transfected cells exhibited marked migratory capacity and the formation of filopodial protrusions. These latter events are consistent with Src activation and, indeed, Src-specific inhibition reversed these phenotypes. Moreover Dsg3 knockdown, which also reversed the decreased level of E-cadherin, partially blocked Src phosphorylation.

CONCLUSIONS/SIGNIFICANCE

Our data are consistent with the possibility that Dsg3, as an up-stream regulator of Src activity, helps regulate adherens junction formation.

A molecular study of desmosomes identifies a desmoglein isoform switch in head and neck squamous cell carcinoma

Desmosomes, the intercellular junctions that confer strong adhesion between epithelial cells, are frequently altered in malignancy. However, a comprehensive analysis of these structures has not been carried out in oral neoplasia. Oral squamous cell carcinomas (SCCs) and pre-malignant dysplasia can be sub-classified according to their in vitro replicative lifespan, where the immortal dysplasia (ID) and carcinoma (IC) subsets have p16(ink4a) and p53 dysfunction, telomerase deregulation and genetic instability and the mortal subset (MD and MC) do not. We found that the desmosomal proteins exhibit a distinct expression pattern in oral mucosa when compared with epidermis in vivo. Microarray data from a large panel of lines revealed that the transcript levels of DSG3, DSC2/3, DP, PG and PKP1 were reduced in ID and IC. Interestingly, DSG2 was up-regulated in MC. Reduction of DSG3 and up-regulation of DSG2 were found in two independent microarray datasets. Significantly, we demonstrated that reduction of DSG3 and up-regulation of DSG2 was reversible in vitro by using RNAi-mediated knockdown of DSG2 in IC cells. The remaining desmosomal proteins were largely disrupted or internalized and associated with retraction of keratin intermediate filaments in oral SCC lines. These findings suggest dysfunction and loss of desmosomal components are common events in the immortal class of oral SCC and that these events may precede overt malignancy.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

Desmoglein 3 is overexpressed in inverted papilloma and squamous cell carcinoma of sinonasal cavity

OBJECTIVES/HYPOTHESIS

We sought to investigate the role of desmoglein 3 in pathogenesis of sinonasal inverted papilloma (IP) and its malignant transformation.

METHODS

Fifteen subjects with sinonasal IP and 15 subjects of normal sphenoid sinus mucosa were enrolled. Each specimen was divided into two portions: one for mRNA expression analysis by real-time polymerase chain reaction, and the other for detection of targeted proteins by immunohistochemistry analysis. In addition, another 10 cases of IP with squamous cell carcinoma (SCC) were added for immunohistochemistry analysis.

RESULTS

The mRNA expression level of desmoglein 3 was significantly higher in IP tissues than in the normal sinus mucosa (P < .001). In immunohistochemistry study, desmoglein 3 was detected in plasma membrane areas of IP and IP with SCC tissues, but no obvious expression was found in normal sinus mucosa (total score; both P < .001). Positive desmoglein 3 staining was strongly present in nearly all malignant transformation areas of IP with SCC cases (90%), but only in scattered areas of some cases of IP (53%) (total score; P < .001).

CONCLUSIONS

Desmoglein 3 was overexpressed in IP and IP with SCC, and the overexpression was correlated with malignant transformation of IP. It may provide valuable insight into the pathobiology of this disease, and can potentially provide a venue to predict malignant transformation in sinonasal IP.

Desmocollin-3: a new marker of squamous differentiation in undifferentiated large-cell carcinoma of the lung

Lung cancer classification in small-cell and non-small-cell types was recently challenged by data on the differential efficacy of new cytotoxic agents in specific histotypes. An accurate histotype definition has therefore gained interest in both preoperative and surgical materials, but is a hard task especially in undifferentiated large-cell tumors lacking morphological signs of squamous or glandular differentiation. The responsiveness of these latter subtypes to new drugs apparently more selective for adenocarcinomas or squamous carcinomas is not fully understood, also due to the heterogeneity of diagnostic criteria for this tumor entity. Current immunohistochemical markers are not fully specific and new molecules are to be explored. On the basis of gene expression profiling data, reporting a remarkable differential expression of desmocollin-3 (a protein localized in desmosomal junctions of stratified epithelial) between adeno- and squamous cancers, we immunostained 62 cases of resected undifferentiated large-cell lung carcinomas for desmocollin-3 (and for TTF-1, p63 and mucin stain), to test its ability to identify a (residual) squamous phenotype, if present. Desmocollin-3 was expressed in almost half of the undifferentiated large-cell cancers and was mutually exclusive with TTF-1 (positive in 39%; the remaining 18 % of cases was double negative). Special large-cell carcinoma variants expressed desmocollin-3 in 6 of 6 basaloid, 7 of 12 clear-cell types, again mutually exclusive with TTF-1 expression. None of seven sarcomatoid carcinomas reacted for either marker. In 31 cytological samples diagnosed as 'non-small-cell lung carcinoma', desmocollin-3 was again mutually exclusive with TTF-1 and stained all squamous carcinomas, 1 of 19 adenocarcinoma only, and 50% of large-cell carcinoma (all histologically confirmed). This combined morphophenotypic approach may represent a valid adjunct (for both surgical and cytological samples) in the selection of patients with lung cancer to medical treatments tailored according to different efficacy in different lung carcinomas of the squamous, adeno- and large-cell types.

Glucose transporter-1 in pulmonary neuroendocrine carcinomas: expression and survival analysis

Glucose transporter-1 (GLUT-1) mediates the transport of glucose across the cellular membrane. Its elevated levels and/or activation have been shown to be associated with malignancy. The aim of this study was to investigate GLUT-1 expression in pulmonary neuroendocrine carcinomas. Tissue microarray-based samples of 178 neuroendocrine carcinomas, including 48 typical carcinoids, 31 atypical carcinoids, 27 large cell neuroendocrine carcinomas and 72 small cell carcinomas from different patients, were studied immunohistochemically for GLUT-1 expression. Forty-seven percent (75/161) of pulmonary neuroendocrine carcinomas were immunoreactive with GLUT-1. GLUT-1 was observed in 7% (3/46) of typical carcinoid, 21% (6/29) of atypical carcinoid, 74% (17/23) of large cell neuroendocrine carcinoma and 78% (49/63) of small cell carcinoma. GLUT-1 expression correlated with increasing patient age (P=0.01) and with neuroendocrine differentiation/tumor type (P<0.001), but not with gender, tumor size or stage. GLUT-1 expression was seen in a characteristic membranous pattern of staining along the luminal borders or adjacent to necrotic areas. GLUT-1 expression was associated with an increased risk of death for neuroendocrine carcinomas as a group (risk ratio=2.519; 95% confidence interval=1.519-4.178; P<0.001) and carcinoids (risk ratio=4.262; 95% confidence interval=1.472-12.343; P=0.01). In conclusion, GLUT-1 is expressed in approximately half of the pulmonary neuroendocrine carcinomas and shows a strong correlation with neuroendocrine differentiation/grade, but not with other clinicopathologic variables. Further studies appear plausible to elucidate the prognostic significance of GLUT-1 expression in pulmonary carcinoids.

The role of desmoglein-3 in the diagnosis of squamous cell carcinoma of the lung

Results from several microarray-based studies have led to the identification of up-regulated expression levels of the DSG3 gene in pulmonary squamous cell carcinomas (SQCCs). The purpose of this study was to determine the role of DSG3 expression in the diagnosis of SQCCs of the lung and to compare DSG3 with p63, CK5, and CK6, as markers of squamous cell differentiation. Expression of DSG3 mRNA was evaluated in bulk laser capture microdissection-derived microarray data and by quantitative reverse transcription PCR on both SQCCs and adenocarcinomas. Expression levels of p63, CK5, and CK6 were evaluated in microarray data from the same set. An immunohistochemical study using antibodies directed against DSG3, p63, and CK5/6 was also performed. DSG3 was over-expressed in SQCCs but had very limited expression in both adenocarcinomas and non-neoplastic lungs. The microarray data showed that DSG3 had a sensitivity and specificity of 88% and 98%, respectively, in detecting SQCC versus adenocarcinoma. In comparison, sensitivity and specificity was 92% and 82% for p63, and 85% and 96% for CK5, respectively. The correlation coefficient between the microarray and immunohistochemical data for these genes was greater than or equal to 0.9. Using immunohistochemistry, sensitivity and specificity of DSG3 for lung cancers were 98% and 99%, respectively. Therefore, DSG3 can be a useful ancillary marker to separate SQCC from other subtypes of lung cancer.

Tissue microarrays enabling high-throughput molecular pathology

The tissue microarray has enabled high-throughput pathology. Rather than the laborious review of individual slides and issues of assay reproducibility across large series of specimens, tissue microarrays allow the review of a single stain on a single slide containing tens to hundreds of samples. This is a paradigm shift in pathology, away from histomorphology and toward molecular characterization by immunohistochemistry. This platform allows large retrospective clinical studies of biomarkers for correlation with outcome and can equally well be applied toward high-throughput analysis of cell lines and xenografts. Tissue microarrays encourage novel approaches to assaying tissue with retained histomorphology and have enabled image analysis in pathology. The reduction of tissue to an analyte for high-throughput analysis has highlighted the importance of a high quality tissue and the impact of tissue handling and processing in the quality of data that can be obtained from analysis of tissue.