An Easy Method for Manual Construction of High-density Tissue Arrays

Constructing high-density tissue microarrays with a novel method and a self-made tissue-arraying instrument

Tissue microarrays (TMAs), also called tissue chips, contain hundreds to thousands of tissue cores obtained from different tissue donor blocks. By using TMA technology, a molecular marker, such as protein, RNA or DNA, can be simultaneously examined in hundreds of different specimens under the same experimental conditions. A growing number of previous studies have introduced different methods for constructing TMAs. Many authors tried to use various methods to implant more tissue cores in a single recipient block, and most of these methods involved reducing the diameter of the tissue cores and/or the spacing between adjacent tissue cores. However, when creating TMAs, it is difficult to reduce the distance between tissue cores to zero except with extremely expensive automatic TMA arrayers. Here, we introduce a novel method to construct a high-density TMA that does not have spacing between the tissue cores. We also introduce a method for preparing a self-made tissue-arraying instrument. With this method and the tissue-arraying instrument, we successfully created a TMA containing 126 tissue cores that were 2 mm in diameter. H&E staining and immunohistochemical staining were performed on the sections cut from the TMA without any tissue spot loss. This method is easy to operate, and the materials for creating the tissue-arraying instrument are inexpensive and can be purchased anywhere. Therefore, this method can be applied in all laboratories.

Tissue microarrays - brief history, techniques and clinical future

Introduction and Aim: There is a growing need for better, cheaper and faster histopathological diagnostic. The authors reviewed the main steps of the efforts towards the improvement of the pre-analytical phase of tissue processing for histological examination. Results: Since their introduction decades ago tissue microarrays (TMAs) proved their value by increasing efficiency, standardization and accuracy of many histological techniques, such as histochemistry, histoenzymology, immunohistochemistry, in situ hybridization, etc. By allowing the simultaneous analysis and comparison of multiple different tissues on a single histology slide (up to 1000 individual samples), TMAs are also having a significant economic advantage (consumables and labor). From its first description until recent years, the TMA techniques have evolved steadily but slowly despite many attempts to adapt it for clinical diagnostics. In this paper, we are reviewing the main techniques of obtaining TMA blocks from the beginning to the present day, as well as recent developments that are expanding their scope into high accuracy/efficiency clinical diagnostics. Conclusions: Considering recent developments, we believe that the prospect of high-throughput histology might be achievable in the not-so-distant future.

Simple method for constructing and repairing tissue microarrays using simple equipment

OBJECTIVE

Many methods for tissue microarray (TMA) construction were described in previous reports. Because TMA-based methods are expensive and complicated, their widespread application may be restricted. This study aimed to develop a simple method for TMA construction.

METHODS

High-density TMAs were constructed using simple equipment, and hematoxylin and eosin and immunohistochemical staining were performed to analyze the effect on the TMA block.

RESULTS

A recipient block with 162 holes of 0.9 mm in diameter was prepared using a mini-drill and plastic mold. Tissue cores of 1.0 mm in diameter were obtained from multiple donor blocks with stainless-steel capillary tubes driven by the mini-drill. Under the fixation and guidance of the plastic mold, tissue cores could be easily injected into the holes in the recipient block by inserting a stainless-steel wire into the stainless-steel tube with the tissue core and then pressing using the stainless-steel wire.

CONCLUSION

A high-density TMA block with 162 1.0-mm cores was created. This new modified technique could be a good alternative in many laboratories.

ATMAD: robust image analysis for Automatic Tissue MicroArray De-arraying

Background

Over the last two decades, an innovative technology called Tissue Microarray (TMA), which combines multi-tissue and DNA microarray concepts, has been widely used in the field of histology. It consists of a collection of several (up to 1000 or more) tissue samples that are assembled onto a single support – typically a glass slide – according to a design grid (array) layout, in order to allow multiplex analysis by treating numerous samples under identical and standardized conditions. However, during the TMA manufacturing process, the sample positions can be highly distorted from the design grid due to the imprecision when assembling tissue samples and the deformation of the embedding waxes. Consequently, these distortions may lead to severe errors of (histological) assay results when the sample identities are mismatched between the design and its manufactured output. The development of a robust method for de-arraying TMA, which localizes and matches TMA samples with their design grid, is therefore crucial to overcome the bottleneck of this prominent technology.

Results

In this paper, we propose an Automatic, fast and robust TMA De-arraying (ATMAD) approach dedicated to images acquired with brightfield and fluorescence microscopes (or scanners). First, tissue samples are localized in the large image by applying a locally adaptive thresholding on the isotropic wavelet transform of the input TMA image. To reduce false detections, a parametric shape model is considered for segmenting ellipse-shaped objects at each detected position. Segmented objects that do not meet the size and the roundness criteria are discarded from the list of tissue samples before being matched with the design grid. Sample matching is performed by estimating the TMA grid deformation under the thin-plate model. Finally, thanks to the estimated deformation, the true tissue samples that were preliminary rejected in the early image processing step are recognized by running a second segmentation step.

Conclusions

We developed a novel de-arraying approach for TMA analysis. By combining wavelet-based detection, active contour segmentation, and thin-plate spline interpolation, our approach is able to handle TMA images with high dynamic, poor signal-to-noise ratio, complex background and non-linear deformation of TMA grid. In addition, the deformation estimation produces quantitative information to asset the manufacturing quality of TMAs.

Electronic supplementary material

The online version of this article (10.1186/s12859-018-2111-8) contains supplementary material, which is available to authorized users.

Tissue Microarray Analysis Applied to Bone Diagenesis

Taphonomic processes affecting bone post mortem are important in forensic, archaeological and palaeontological investigations. In this study, the application of tissue microarray (TMA) analysis to a sample of femoral bone specimens from 20 exhumed individuals of known period of burial and age at death is described. TMA allows multiplexing of subsamples, permitting standardized comparative analysis of adjacent sections in 3-D and of representative cross-sections of a large number of specimens. Standard hematoxylin and eosin, periodic acid-Schiff and silver methenamine, and picrosirius red staining, and CD31 and CD34 immunohistochemistry were applied to TMA sections. Osteocyte and osteocyte lacuna counts, percent bone matrix loss, and fungal spheroid element counts could be measured and collagen fibre bundles observed in all specimens. Decalcification with 7% nitric acid proceeded more rapidly than with 0.5 M EDTA and may offer better preservation of histological and cellular structure. No endothelial cells could be detected using CD31 and CD34 immunohistochemistry. Correlation between osteocytes per lacuna and age at death may reflect reported age-related responses to microdamage. Methodological limitations and caveats, and results of the TMA analysis of post mortem diagenesis in bone are discussed, and implications for DNA survival and recovery considered.

Krüppel-like factor 4 is a novel prognostic predictor for urothelial carcinoma of bladder and it regulates TWIST1-mediated epithelial-mesenchymal transition

BACKGROUND

Krüppel-like factor 4 (KLF4) exerts tumor suppressive or oncogenic functions in a cell-type-dependent manner, but its prognostic role in urothelial carcinoma of bladder (UCB) remains unclear. We aimed to determine how KLF4 regulates epithelial-mesenchymal transition (EMT) and predicts patient survival in UCB.

PATIENTS AND METHODS

The roles of KLF4 and other EMT regulators in cancer progression were studied in UCB specimens of 398 patients, UCB cell lines. The results were validated by open-access The Cancer Genome Atlas dataset.

RESULTS

Over a median follow-up of 46.5 months, tissue microarray demonstrated that strong KLF4 expression was associated with higher risk toward metastasis and death (P<0.001). KLF4 expression positively correlated with TWIST1 and vimentin, and inversely correlated with E-cadherin expression. Metastasis-free survival was poorest in KLF4/TWIST1 coexpression group, followed by KLF4 or TWIST1 expression-alone group, and no-expression group (P<0.001). Multivariate analysis substantiated that KLF4/TWIST1 coexpression independently predicted overall mortality and metastasis risk with hazard ratios of 2.43 (95% CI: 1.65-3.64) and 7.54 (CI: 4.03-12.10). The Cancer Genome Atlas dataset of bladder cancer also revealed a trend toward decreased overall survival in the high KLF4 expression group as compared to the low KLF4 group. In vitro, KLF4 is accompanied with decreased E-cadherin and β-catenin expressions, increased vimentin and fibronectin expressions, and enhanced migration/invasion. KLF4 knockdown suppressed TWIST1 expression and inhibited EMT, migration and invasion, whereas enforced KLF4 overexpression activated TWIST1 expression and restored EMT and metastatic phenotype. Furthermore, TWIST1 knockdown abolished KLF4-faciliated EMT and metastatic feature without affecting KLF4 expression.

CONCLUSIONS

KLF4 promotes TWIST1-mediated EMT and may represent a novel prognostic predictor in UCB.

Overview on Techniques to Construct Tissue Arrays with Special Emphasis on Tissue Microarrays

With the advent of new histopathological staining techniques (histochemistry, immunohistochemistry, in situ hybridization) and the discovery of thousands of new genes, mRNA, and proteins by molecular biology, the need grew for a technique to compare many different cells or tissues on one slide in a cost effective manner and with the possibility to easily track the identity of each specimen: the tissue array (TA). Basically, a TA consists of at least two different specimens per slide. TAs differ in the kind of specimens, the number of specimens installed, the dimension of the specimens, the arrangement of the specimens, the embedding medium, the technique to prepare the specimens to be installed, and the technique to construct the TA itself. A TA can be constructed by arranging the tissue specimens in a mold and subsequently pouring the mold with the embedding medium of choice. In contrast, preformed so-called recipient blocks consisting of the embedding medium of choice have punched, drilled, or poured holes of different diameters and distances in which the cells or tissue biopsies will be deployed manually, semi-automatically, or automatically. The costs of constructing a TA differ from a few to thousands of Euros depending on the technique/equipment used. Remarkably high quality TAs can be also achieved by low cost techniques.

No-cost manual method for preparation of tissue microarrays having high quality comparable to semiautomated methods

Manual tissue microarray (TMA) construction had been introduced to avoid the high cost of automated and semiautomated techniques. The cheapest and simplest technique for constructing manual TMA was that of using mechanical pencil tips. This study was carried out to modify this method, aiming to raise its quality to reach that of expensive ones. Some modifications were introduced to Shebl's technique. Two conventional mechanical pencil tips of different diameters were used to construct the recipient blocks. A source of mild heat was used, and blocks were incubated at 38°C overnight. With our modifications, 3 high-density TMA blocks were constructed. We successfully performed immunostaining without substantial tissue loss. Our modifications increased the number of cores per block and improved the stability of the cores within the paraffin block. This new, modified technique is a good alternative for expensive machines in many laboratories.

Prognostic significance of heat shock proteins in urothelial carcinoma of the urinary bladder

AIMS

Heat shock proteins (HSPs) are a group of molecules induced by a variety of environmental and pathophysiological stresses, including cancer. The expression of HSPs has been implicated in the regulation of apoptosis and immunity in neoplasia. The purpose of this study was to evaluate the expression and clinicopathological relevance of several HSPs in urothelial carcinomas of the urinary bladder.

METHODS AND RESULTS

Immunohistochemical staining for HSP27, HSP60, HSP70 and HSP90 was performed on samples collected from 744 clinical cases. The results were correlated with clinicopathological characteristics using univariate and multivariate analyses. High expression of HSP70 predicted recurrence of non-muscle-invasive urothelial carcinoma treated by transurethral resection, and low expression of HSP27 correlated with progression and cancer-specific mortality for non-muscle-invasive cancers treated by transurethral resection. Low expression of HSP27 also predicted cancer-specific mortality for patients who underwent cystectomy.

CONCLUSIONS

Both HSP27 and HSP70 impact on the biological behaviour of urothelial carcinomas of the urinary bladder. Immunohistochemical assessment of HSPs can provide useful prognostic information that could ultimately help to develop individualized surveillance programmes.

Construction of high-density tissue microarrays at low cost by using self-made manual microarray kits and recipient paraffin blocks

BACKGROUND

Advances of tissue microarray (TMA) technology have enabled simultaneous in situ analysis of biomarker expression in a large number of archived pathology specimens. However, the relatively high cost of TMA construction may hamper many researchers from using this essential tool of modern pathology research. We discuss methods for making TMA kits and recipient blocks for manual construction of high-density TMAs at low cost.

METHODS

Ordinary cannula piercing needles, hypodermic needles, bone marrow biopsy needles, metallic ink cartridges of ballpoint pens, and disposable skin biopsy punches were used to construct self-made manual TMA kits. The recipient blocks were manufactured by boring holes in the conventional bare paraffin blocks. A mini electric hand drill and a microcompound table assembled on a drill stand were used to maximize the capacity of the recipient blocks.

RESULTS

By using TMA kits made from cannula piercing needles (16- and 18-gauge), it was possible to construct TMAs with 1 mm×140 cores, 0.6 mm×320 cores, 2 mm×70 cores, 3 mm×35 cores, and 5 mm×12 cores. The capacity of the recipient blocks could be dramatically increased by drilling holes.

CONCLUSIONS

Construction of TMAs using self-made TMA kits is an inexpensive alternative to construction of TMAs using commercial devices.

Her2 amplification distinguishes a subset of non-muscle-invasive bladder cancers with a high risk of progression

Background

Several studies have employed immunohistochemistry to detect Her2/neu overexpression in urothelial carcinomas, yielding a tremendous range of positive expression rates. Few studies have examined Her2 status in non-muscle invasive bladder cancer (NMIBC) using fluorescence in situ hybridisation (FISH).

Aim

To evaluate Her2 amplification in NMIBC (Ta/T1), to correlate the findings with recurrence and progression, and compare the Her2 status between primary and progressive tumours.

Methods

FISH and immunohistochemistry for Her2/neu were performed on tissue arrays consisting of 36 papillary urothelial neoplasms of low malignant potential (PUNLMPs), 190 low grade urothelial carcinomas (LG-UCs) and 178 high grade urothelial carcinomas (HG-UCs). 32 cases with specimens of both primary and progressive tumours (from Ta/T1 to T2–4) were included for comparative analyses.

Results

16 HG-UCs (9.0%) showed Her2 gene amplification while none of the PUNLMPs and LG-UCs showed this aberration. There was 100% concordance in the status of Her2 amplification between primary and progressive lesions. Immunohistochemistry and FISH results were in closest agreement when overexpression was defined as 50% of tumour cells showing immunoreactivity. The cumulative incidences of recurrence and progression in Her2-amplified HG-UC were significantly higher than in those without amplification.

Conclusions

A subset of high-grade NMIBCs contain Her2 amplification and are associated with markedly aggressive behaviour. Her2 diagnostics are valuable for distinguishing patients who require diligent surveillance and would potentially benefit from anti-Her2 therapies.

Improved technique for manually constructing tissue microarrays for large-core arrays

Tissue microarrays were originally developed to enable alignment of multiple tissue cores in a single paraffin block and to enable high-throughput laboratory analysis. However, a major drawback is the loss of tissue cores during slide preparation, especially when sectioning the tissue block. Tissue cylinders directly aligned in the metal box without preheating tend to detach from the surrounding paraffin, which results in incomplete or folded tissue sections. The proposed solution is preheating all tissue cylinders on a hot plate to facilitate fusion between the paraffin within the core and the paraffin surrounding the core. In this study, 6 tissue microarray blocks were constructed from 528 tissue cores extracted from various formalin-fixed, paraffin-embedded human tissue samples. The tissue cores in the arrays revealed good homogenization with the surrounding paraffin wax, and the tissue sections were obtained intact. Both hematoxylin-eosin and immunohistochemical staining confirmed satisfactory results. This simple and economical method is easily performed in the laboratory without expensive instrumentation.

Activation of the PI3K/Akt/mTOR pathway correlates with tumour progression and reduced survival in patients with urothelial carcinoma of the urinary bladder

AIMS

Phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway dysregulation has been implicated in the development of urothelial carcinoma. However, its clinical relevance has not been substantially validated in human samples. The aim of this study was to assess the expression of the pathway in a large cohort of bladder cancers using the tissue microarray technique.

METHODS AND RESULTS

Immunohistochemical stains for phosphatase and tensin homologue (PTEN), phosphorylated Akt, mTOR, S6 and 4E-BP1 were performed for 887 cases, and the results were correlated with clinicopathological characteristics. The high expression of p-S6 and p-Akt corresponded significantly with high-grade and advanced-stage, while losses of PTEN and p-4E-BP1 were observed more often in high-grade and high-stage tumours. High expression of p-Akt and p-S6 predicted progression and cancer-specific mortality for non-muscle-invasive cancers treated by transurethral resection, and p-Akt was an independent factor in multivariate analysis. High expression of p-mTOR and p-Akt correlated with higher cumulative incidence of cancer-specific mortality for muscle-invasive cancer, and p-mTOR was an independent prognostic factor.

CONCLUSIONS

We have demonstrated the impact of PI3K/Akt/mTOR alteration on the biological behaviour of bladder tumours. Proper immunohistochemical examination of the PI3K/Akt/mTOR pathway can provide useful prognostic information, and the findings may represent an additional therapeutic avenue in the treatment of bladder cancers.

Expression of syndecan-1 in papillary carcinoma of the thyroid with extracapsular invasion

BACKGROUND AND AIMS

Syndecan-1 (SDC-1) is a member of the family of transmembrane heparan sulfate proteoglycans, which are involved in cell-cell adhesion and the interaction of cells with the extracellular matrix. Evidence suggests that loss of SDC-1 expression in several benign and malignant epithelial neoplasms is an unfavorable prognostic indicator, but its expression profile in thyroid gland neoplasms remains to be elucidated. The aim of this study was to evaluate SDC-1 expression in papillary carcinomas of the thyroid (PCT) that were both larger and smaller (papillary microcarcinoma) than 10mm, with or without extracapsular extension (PCT-E and PCT-NE).

METHODS

The expression of SDC-1 was studied in 62 cases of PCT-E and PCT-NE using a tissue microarrays technique (TMA). SDC-1 positivity was predominantly observed in the cytoplasm of neoplastic epithelial cells and in the stroma of PCT.

RESULTS

SDC-1 is expressed in both neoplastic epithelial cells and the stroma. It is more frequently expressed in PCT-E than PCT-NE (p=0.002) and the stromal expression of SDC-1 is more intense in PCT-E that are >10 mm (p=0.026).

CONCLUSIONS

The epithelial and stromal expression of SDC-1 observed in this series of PCT suggests that the expression of this protein may be related to extracapsular invasion.

Simultaneous phenotyping and genotyping (FICTION-methodology) on paraffin sections and cytologic specimens: a comparison of 2 different protocols

Combining immunofluorescence labeling with fluorescence in situ hybridization (FISH) is a powerful technique simultaneously studying immunophenotypic markers and genetic abnormalities present in tumor cells [the FICTION method (fluorescence immunophenotyping, and interphase cytogenetics as a tool for the investigation of neoplasms)]. However, few studies have been applied to the technical problems posed by antigen retrieval and accessibility of genetic probes to target-DNA, using formalin-fixed, paraffin-embedded tissue. In this study, we compared 2 immunofluorescence detection systems, the 3-step IF (TIF) method against the Tyramide Signal Amplification techniques (TSA). The FICTION-TSA technique significantly improved the sensitivity for detection of the immunophenotypic markers without influencing specific probe hybridization to target-DNA, compared with the results obtained with the TIF method. The reaction product of the TSA system was robust to the following FISH procedure in contrast to the TIF technique. The TSA technique used also allowed synchronous detection of nuclear antigens and FISH signals using both fusion (IgH/CCND1) and break-apart (CCND1) probes on formalin-fixed paraffin-embedded tissue.

Comparison of immunohistochemical markers in the differential diagnosis of adrenocortical tumors: immunohistochemical analysis of adrenocortical tumors

Most adrenocortical tumors (ACTs) can be diagnosed directly by a combination of morphologic features and clinical findings. However, sometimes it may be difficult to distinguish ACTs from other neoplasms such as pheochromocytomas and some metastatic tumors, particularly for small biopsy specimens because they may be morphologically similar. Expression of calretinin has recently been suggested as a valuable immunomarker for the differential diagnosis between ACTs and other tumors; however, its diagnostic value is still under debate. To determine the diagnostic value of calretinin in Chinese patients with adrenocortical and non-ACTs, we employed both polyclonal and monoclonal anticalretinin to characterize the expression of calretinin in adrenal tissues and compared its expression with that of inhibin alpha, Melan-A, cytokeratin, or CD99 by immunohistochemistry in tissue microarrays and standard tissue sections of 414 specimens. Our results revealed that calretinin was expressed by adrenocortical cells, but not by the other cells tested and the percentage of calretinin-positive ACTs reached 99% when stained with polyclonal antibodies, which was higher than that with monoclonal anticalretinin (91.3%), anti-Melan-A (90.3%), antiinhibin alpha (81.6%). In addition, our results also revealed that ACTs were stained by cytokeratin (AE1/AE3) with variable degrees (58.7%). Furthermore, unlike anti-Melan-A that stained all metastatic malignant melanoma, anticalretinin did not recognize other tested tumors. Therefore, immunohistologic staining with polyclonal anticalretinin is more sensitive than other antibodies tested for the diagnosis of ACTs. However, monoclonal anticalretinin appeared to be more specific. Importantly, our data suggested that the fried-egg-like staining pattern, but not the mere cytoplasmic staining, was characteristic of anticalretinin staining in adrenocortical tissues. Notably, a few anticalretinin negative-ACTs were stained by other immunomarkers that we tested. Thus, the combinational characterization of calretinin (either by polyclonal or monoclonal antibody), inhibin alpha, and Melan-A expression is of great significance in the differential diagnosis of ACTs.

Changing patterns in the frequency of Hodgkin lymphoma subtypes and Epstein-Barr virus association in Taiwan

Epstein-Barr virus (EBV) infection is a risk factor for Hodgkin lymphoma (HL). To test whether the frequency of HL subtypes and their association with EBV has shifted with rising socioeconomic status in Taiwan, we compared the pathological features and EBV status, detected by in situ hybridization, of HL diagnosed between 1996 and 2007 (99 cases) and 1982 and 1995 (74 cases). The male-to-female ratio was 121:52 (2.3:1) and the mean age at presentation was 41.5 years. The overall EBV positivity rate was 50% (86/173 cases). Comparing the distribution of HL cases diagnosed at two different time periods, we found an increased frequency of the nodular sclerosis (NS) subtype (53 vs 68%, P = 0.045), a decreased frequency of the mixed cellularity subtype (35 vs 13%, P < 0.001), a reduced male-to-female ratio (2.9:1 compared to 1.4:1) and mean age (42.4 vs 36.6 years) in the NS subtype, and a significant decrease in EBV positivity rates among the NS and lymphocyte-depletion subtypes (61 vs 39%, P = 0.03). These data indicate shifts in the frequency of histological subtype and EBV association for HL in Taiwan over the last decade, with a trend closer to that seen in Western countries and Japan.

Expression of fascin in oral and oropharyngeal squamous cell carcinomas has prognostic significance - a tissue microarray study of 129 cases

AIMS

To elucidate the role of fascin in oral and oropharyngeal squamous cell carcinoma (OSCC) by correlation with clinical parameters.

METHODS AND RESULTS

Paraffin sections using tissue microarrays of 129 patients with OSCC were investigated immunohistochemically. Fascin protein was overexpressed in OSCC cells compared with their non-neoplastic epithelial counterparts. For evaluating the intensity of fascin, 39 (30.2%) were classified as weakly immunoreactive, 76 (58.9%) as moderate reactive and 14 (10.9%) as intensely reactive. For evaluating the distribution of fascin, 64 (49.6%) were classified as < 55% and 65 (50.4%) were classified as >/= 55%. Fascin protein expression was correlated with size or extent of the tumour (P < 0.001), positive lymph node metastasis (P < 0.001), distant metastasis (P = 0.014) and clinical staging (P < 0.001). The immunoreactivity scores of fascin in OSCC were variable but showed significant correlation with histological grade, clinical TNM system and stage.

CONCLUSION

Expression of fascin protein may play an important role in progression of OSCC. Overexpression of fascin contributes to a more aggressive clinical course and suggests the potential of fascin as a new molecular target for therapeutic intervention.

The survival outcomes of patients with resected non-small cell lung cancer differ according to EGFR mutations and the P21 expression

The aims of this study were to evaluate the prognostic implications of patients with epidermal growth factor receptor (EGFR) mutations and a p21 expression, and to determine their associations in resected non-small cell lung cancer (NSCLC) patients. We sequenced exons 18-21 of the EGFR tyrosine kinase domain by performing mutation analysis of tissues from patients that suffered with NSCLC and who also had undergone surgical resection. The expressions of p21 and p53 were analyzed using immunohistochemistry. We detected EGFR mutations in 24 of 97 patients (25%). EGFR mutations were more frequent in the people who had never smoked than in the smokers (33% versus 14%, respectively; P=.028). The presence of EGFR mutations had no effect on survival. The expression of p21 in the patients with wild-type EGFR tended to be associated with better survival. However, the expression of p21 in the patients with EGFR mutations was associated with poor overall survival (P=.006). The five-year survival rates were 17% for the patients with EGFR mutations and p21 positivity (Group I), 44% for the patients with wild type EGFR (Group II), and 75% for the patients with EGFR mutation and no p21 positivity (Group III) (P=.036). Multivariate analysis that was corrected for age, gender and cancer stage revealed different overall survival outcomes according to the three groups (P=.004). There was no significant correlation between the expressions of p21 and p53. Survival outcomes in the patients with resected NSCLC may be correlated with the presence of a p21 expression and EGFR mutations.

Biological correlates of FDG uptake in non-small cell lung cancer

PURPOSE

Each pathological stage of non-small cell lung cancer (NSCLC) consists of a heterogeneous population containing patients at much higher risk than others. Noninvasive functional imaging modalities, such as 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), could play a role in further characterization of NSCLCs. As many factors can influence the extent of FDG uptake, the underlying mechanisms for FDG accumulation in tumors, are still a matter of debate. The aim of the present study was to investigate these possible mechanisms in the primary site of early stage preoperatively untreated NSCLC.

METHODS

19 patients with early stage NSCLC, who had undergone both preoperative FDG-PET imaging and curative surgery, were enrolled in this study. Standardized uptake values (SUVs) were used for evaluation of primary tumor FDG uptake. Final diagnosis, tumor type, tumor cell differentiation and size of the primary tumors were confirmed histopathologically in resected specimens. Histologic sections were analyzed for amount of inflammation and necrosis. Expression of the glucose membrane transporters (GLUT-1 and GLUT-3); the isoforms of the glycolytic enzyme hexokinase (HK-I, HK-II and HK-III); and the cysteine protease caspase-3, was evaluated immunohistochemically.

RESULTS

FDG uptake was significantly higher in squamous cell carcinomas (mean SUV 13.4+/-4.9, n=8) compared to adenocarcinomas (7.1+/-3.3, n=8, p=0.007), or large cell carcinomas (5.9+/-1.9, n=3, p=0.02). The degree of FDG accumulation seemed to depend especially on GLUT-1, GLUT-3 and tumor cell differentiation. The summed standardized values of these three parameters correlated significantly with the SUV (r=0.47, p=0.05).

CONCLUSION

The present study supports the hypothesis that tumor cell differentiation in combination with overexpression of GLUT-1 and GLUT-3 determine the extent of FDG accumulation and that squamous cell carcinomas accumulate more FDG than adenocarcinomas or large cell carcinomas.

An Agarose Matrix Facilitates Sectioning of Tissue Microarray Blocks

Tissue microarray (TMA) is a powerful, high-throughput technique for in situ investigation of biomarkers in many tissue samples in a paraffin block by immunohistochemistry or fluorescence in situ hybridization (FISH), and has rapidly become the standard in marker studies. One of the difficult steps in the procedure is the sectioning of array blocks and mounting of sections using special slides and/or adhesive-coated tape, which demands specific experience and is time-consuming. We report an arraying method that allows melting of the receiving paraffin block and subsequent sectioning like any ordinary paraffin-embedded tissue block. The major difference from the standard microarray technique is the use of an agarose matrix in the recipient block. The agarose matrix allows melting of the paraffin without disturbing the array, resulting in perfect integration of the tissue cores. The agarose-paraffin TMA blocks limit tissue core loss during cutting, mounting, or immunohistochemical or FISH staining and better maintains the array.

Multitissue array review: A chronological description of tissue array techniques, applications and procedures

We performed a systematic search for literature dealing with tissue microarray technology. During the last two decades, these procedures have developed into a powerful tool for the high-throughput analysis of tissue specimens. This technology offers the following advantages: amplification of a scarce resource, experimental uniformity (tissue of multiple patients are treated in an identical manner), decreased assay volume, preservation of original blocks, amenability to a wide range of techniques and evaluation of tissue from multiple patients on the same slide. Depending on the shape of the tissue sample and the method used to obtain it, multitissue array techniques may be classified into two different groups: rod-shaped tissue techniques and core tissue techniques. These techniques have been used for quality control, diagnosis, and teaching and screening purposes. Some technical aspects should be considered when deciding which technique should be used: the number, size and origin of tissue samples; the quality of paraffin wax, the distance between samples and the depth in the receptor block; antigenicity preservation and block sectioning. This review shows different techniques, the use of which is dependent on the requirements of the arrays and the technical possibilities.

TMA for all: a new method for the construction of tissue microarrays without recipient paraffin block using custom-built needles

BACKGROUND

TMAs are becoming a useful tool for research and quality control methods, mostly for immunohistochemistry and in situ hybridization.

METHODS

A new technique that allows building TMA blocks with more than 300 tissue cores without using a recipient paraffin block for the tissue cores and without using a commercial TMA builder instrument is described. This technique is based on the construction of TMA needles modifying conventional hypodermic needles to punch tissue cores from donor blocks, which are attached by double-side adhesive tape on a computer-generated paper grid used to align the cores on the block mould, which is filled with liquid paraffin.

RESULTS

More than two hundred TMA blocks were constructed using this method, utilized in immunohistochemistry and histochemistry as positive and negative controls and also in research.

CONCLUSION

This technique has the following advantages: it is easy to reproduce, affordable, quick and creates uniform blocks with more than 300 cores aligned, adherent and easy to cut, with negligible losses during cutting and immunohistochemistry and in situ hybridization procedures.

A simple and economical method for the manual construction of well-aligned tissue arrays

Tissue array technology has allowed a substantial progression of studies correlating molecular and immunohistochemical findings with clinico-pathological information. Array construction presents technical difficulties and tissue arrayers are expensive, particularly for small and medium sized laboratories. We describe a simple manual method for producing well-aligned tissue arrays using a hand-made paper mold which can successfully perform immunohistochemical staining. All 200 tissue samples were collected and constructed into blocks by the paper mold. The tissue arrays were smoothly sectioned using a standard microtome and performed for a panel of immunohistochemical study with satisfactory results. This alterative method for building custom arrays could be applied in any laboratory and is both simple and economical.

Increasing expression of serine protease matriptase in ovarian tumors: tissue microarray analysis of immunostaining score with clinicopathological parameters

Matriptase is a type II transmembrane serine protease expressed by cells of surface epithelial origin, including epithelial ovarian tumor cells. Matriptase cleaves and activates proteins implicated in the progression of cancer and represents a potential prognostic and therapeutic target. The aim of this study was to examine the expression of matriptase in ovarian tumors and to assign clinicopathological correlations. Immunohistochemical analysis of matriptase was performed in tissue microarrays of 164 ovarian neoplasms including 84 serous adenocarcinomas, 23 mucinous adenocarcinomas, 10 endometrioid adenocarcinomas, six yolk sac tumors, 12 clear cell carcinomas, six dysgerminomas, eight granulosa cell tumors, four transitional cell carcinomas, five fibromas, and six Brenner tumors. All ovarian tumors except the fibromas and Brenner tumors showed significant expression of matriptase. The matriptase scores were significantly higher in the tumors than in their nontumor counterparts (304+/-26 for serous adenocarcinoma; 361+/-28 for mucinous adenocarcinoma; 254+/-17 for endometrioid adenocarcinoma; 205+/-19 for yolk sac tumor; 162+/-16 for clear cell carcinoma; 109+/-11 for dysgerminoma; 105+/-9 for granulosa cell tumor; and 226+/-18 for transitional cell carcinoma). Matriptase scores in serous adenocarcinoma were correlated with TNM stage and FIGO stage. Our findings demonstrate for the first time that matriptase is overexpressed in many malignant ovarian tumors. It may be a novel biomarker for diagnosis and treatment of malignant ovarian tumors.

Differential immunoprofiles of hepatocellular carcinoma, renal cell carcinoma, and adrenocortical carcinoma: a systemic immunohistochemical survey using tissue array technique

The differential diagnoses of hepatocellular carcinoma (HCC), renal cell carcinoma (RCC), and adrenocortical carcinoma (ACC) are sometimes difficult due to their overlapping histologic features. Immunohistochemistry is a helpful adjunct in supporting the histologic diagnosis. In this study, the authors used the tissue array technique to systemically analyze the efficacy of different immunohistochemical panels in discerning these neoplasms. Immunohistochemical stains were performed on a total of 895 tumors (including 170 HCCs, 176 RCCs, and 40 ACCs) using monoclonal antibodies against hepatocyte antigen (HPA), CD10, RCC marker, vimentin, alpha-inhibin, keratins (KL-1, CAM 5.2, 7, and 20), epithelial membrane antigen, and polyclonal antibodies against carcinoembryonic antigen (pCEA) and alpha-fetoprotein, and antibodies Melan-A (A103), MOC31, and BG8. HPA immunostain alone detected 85.9% of HCCs, and the addition of canalicular pattern of pCEA and CD10 immunostains raised the sensitivity to 94.7%. RCC marker was positive in 54.5% of RCCs but was negative in all non-RCC tumors. Using positive CD10 and negative HPA and pCEA together with RCC marker increased the sensitivity to 74.4%. Immunoreactivity for alpha-inhibin and A103 could be detected in 67.5% and 55% of ACCs, respectively. When the two antibodies were combined, 82.5% of ACCs were labeled. Proper selection of immunohistochemical stains aid in the differential diagnosis of the three neoplasms. Using the tissue array technique, the authors also showed an effective model for comprehensive antibody testing.