The effect of fixation and processing on the sensitivity of oestrogen receptor assay by immunohistochemistry in breast carcinoma

Compartmental Syndecan-1 (CD138) expression as a novel prognostic marker in triple-negative metaplastic breast cancer

BACKGROUND

Metaplastic breast cancer (MpBC) is rare, aggressive, and mostly triple-negative (TN) subtype of BC. We aimed to investigate the potential prognostic significance of Syndecan-1 (SDC1/CD138) expression in this unique tumor.

METHODS

Archived charts of 50 TNBC patients [21 MpBC and 29 invasive ductal carcinoma (IDC)] were retrospectively evaluated. Corresponding paraffin blocks were used for immunohistochemical (IHC) staining of SDC1. Compartmental (epithelial membranous, stromal, and cytoplasmic) staining scores were expressed in quartiles (Q) and correlated with disease-free survival (DFS) and overall survival (OS).

RESULTS

The median follow-up period was 54.6 months (range: 2.2-112.7). MpBC patients showed significantly worse DFS and OS than IDC (p = 0.007 and 0.004, respectively). MpBC demonstrated significantly higher Q4 stromal and membranous SDC1 compared to IDC (p = 0.016 and 0.021, respectively), whereas IDC exhibited significantly higher cytoplasmic Q4 SDC1 than MpBC (p = 0.015). Stromal Q4 SDC1 expression was found to be an independent factor associated with MpBC relative to IDC (OR: 6.7, 95% CI: 1.24-36.90; p = 0.028). Stromal Q4 SDC1 expression was also an independent prognostic parameter for worse DFS and OS compared to Q1-3 in the whole cohort (HR: 4.2, 95% CI: 1.6-10.5; p = 0.003 and HR: 5.8; 95% CI: 2.2-15.3; p < 0.001, respectively). In MpBC, cytoplasmic Q1-3 SDC1 expression was an independent prognostic indicator for worse OS compared with their IDC counterparts (HR: 2.837, 95% CI: 1.048-7.682; p = 0.04).

CONCLUSION

This study suggests, for the first time, that differential expression and localization of SDC1 may contribute to the pathogenesis and prognosis of TN-MpBC. Therefore, targeting SDC1 (CD138) could emerge as a novel therapeutic approach for this devastating disease.

Dormant cardiac stem cells: A promising tool in cardiac regeneration

Stem cells represent an old niche with various new potential therapeutics. Besides drug treatment, reperfusion procedures and surgical revascularization, stem cell therapy could be a good option in ischemic cardiac diseases. A study was performed on a small group of cases who died of cardiac arrhythmia secondary to scarring myocardial infarctions. Tissue cardiac samples were taken from these cases (from the anterior and lateral wall of the left ventricle), for microscopy examination, in order to investigate the presence of cardiac stem cells (CSC). Multiple series of histological sections were also performed and examined, along with immunohistochemical analysis (IHC). The cells were identified in close contact with the residual ischemic cardiomyocytes, in the proximity of the myocardial collagenous scar, in old myocardial infarctions. They were activated by hypoxic ischemia and were influenced by the capillary microvascular density and the interstitial micro-environment conditions. In chronic intermittent ischemia they seem to turn themselves from dormant quiescent cells into activated progenitor committed cells.

Preanalytics and Precision Pathology: Pathology Practices to Ensure Molecular Integrity of Cancer Patient Biospecimens for Precision Medicine

Biospecimens acquired during routine medical practice are the primary sources of molecular information about patients and their diseases that underlies precision medicine and translational research. In cancer care, molecular analysis of biospecimens is especially common because it often determines treatment choices and may be used to monitor therapy in real time. However, patient specimens are collected, handled, and processed according to routine clinical procedures during which they are subjected to factors that may alter their molecular quality and composition. Such artefactual alteration may skew data from molecular analyses, render analysis data uninterpretable, or even preclude analysis altogether if the integrity of a specimen is severely compromised. As a result, patient care and safety may be affected, and medical research dependent on patient samples may be compromised. Despite these issues, there is currently no requirement to control or record preanalytical variables in clinical practice with the single exception of breast cancer tissue handled according to the guideline jointly developed by the American Society of Clinical Oncology and College of American Pathologists (CAP) and enforced through the CAP Laboratory Accreditation Program. Recognizing the importance of molecular data derived from patient specimens, the CAP Personalized Healthcare Committee established the Preanalytics for Precision Medicine Project Team to develop a basic set of evidence-based recommendations for key preanalytics for tissue and blood specimens. If used for biospecimens from patients, these preanalytical recommendations would ensure the fitness of those specimens for molecular analysis and help to assure the quality and reliability of the analysis data.

Role of FGFR3 in Urothelial Carcinoma

BACKGROUND AND OBJECTIVE

This study was undertaken to analyze the immunohistochemical expression of fibroblast growth factor receptor (FGFR3) in urothelial carcinoma and correlate its expression with the pathological stage, recurrence and other clinicopathological parameters.

MATERIAL AND METHODS

A retrospective study was undertaken on paraffin blocks of 55consecutiveurothelial carcinoma specimens in 28 months received in Sri Ramachandra Medical College, Chennai, India. Blocks with the sections containing the tumor and adjacent normal epithelium were chosen for the immunohistochemical (IHC) study of FGFR3.

RESULTS

IHC expression of FGFR3 in high grade (HG) invasive urothelial carcinoma was positive in 18% cases, 66.7% of HG non-invasive urothelial and 82.6% of low grade (LG) non-invasive urothelial carcinomas. The FGFR3 expression was presented in 78.1% of non-invasive carcinoma. In case of invasive urothelial carcinoma, the FGFR3 positivity was observed in 18.2% of tumors (P<0.05).FGFR3 expression in LG tumors was positive in 82.6 % of the cases whereas 32.3% of HG cases were positive for FGFR3 (P<0.05).FGFR3 was expressed in 14.3 % of HG invasive tumors which recurred. HG non-invasive tumors were positive for FGFR3 in 80% of the cases. LG non-invasive tumors were positive for FGFR3 in 72.7% of cases (P<0.05).

CONCLUSION

The expression of FGFR3 is higher in low grade, non-invasive tumors and recurrent non-invasive tumors. The targeted therapy for FGFR3 may be used as one of the modes of treatment for urothelial carcinoma. It can also be used as a marker to determine the grade in difficult cases and the risk of recurrence.

Improving accuracy of breast cancer biomarker testing in India

There is a global mandate even in countries with low resources to improve the accuracy of testing biomarkers in breast cancer viz. oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2neu) given their critical impact in the management of patients. The steps taken include compulsory participation in an external quality assurance (EQA) programme, centralized testing, and regular performance audits for laboratories. This review addresses the status of ER/PR and HER2neu testing in India and possible reasons for the delay in development of guidelines and mandate for testing in the country. The chief cause of erroneous ER and PR testing in India continues to be easily correctable issues such as fixation and antigen retrieval, while for HER2neu testing, it is the use of low-cost non-validated antibodies and interpretative errors. These deficiencies can however, be rectified by (i) distributing the accountability and responsibility to surgeons and oncologist, (ii) certification of centres for testing in oncology, and (iii) initiation of a national EQA system (EQAS) programme that will help with economical solutions and identifying the centres of excellence and instill a system for reprimand of poorly performing laboratories.

Understanding preanalytical variables and their effects on clinical biomarkers of oncology and immunotherapy

Identifying a suitable course of immunotherapy treatment for a given patient as well as monitoring treatment response is heavily reliant on biomarkers detected and quantified in blood and tissue biospecimens. Suboptimal or variable biospecimen collection, processing, and storage practices have the potential to alter clinically relevant biomarkers, including those used in cancer immunotherapy. In the present review, we summarize effects reported for immunologically relevant biomarkers and highlight preanalytical factors associated with specific analytical platforms and assays used to predict and gauge immunotherapy response. Given that many of the effects introduced by preanalytical variability are gene-, transcript-, and protein-specific, biospecimen practices should be standardized and validated for each biomarker and assay to ensure accurate results and facilitate clinical implementation of newly identified immunotherapy approaches.

Breast Cancer Reporting in Lagos, Nigeria: Implications for Training and Education in Africa

PURPOSE

To assess the completeness and accuracy of breast cancer pathologic reporting in Nigeria.

MATERIALS AND METHODS

The histologic parameters provided in breast cancer pathology reports at a large teaching hospital in Nigeria were assessed. The corresponding slides were reviewed after the United Kingdom Royal College of Pathologists guidelines, and results were compared.

RESULTS

Out of 115 breast cancer cases, histologic type of breast carcinoma was concordant with the review type in 53.1% of cases and discordant in 46.9%. Grading was stated in 89.62% of cases, of which 50.5% were correctly graded, 35.8% were under-graded, and 8.5% were over-graded. Poor fixation and omission of the mitotic count were the main reasons for discordant grades. A comment on lymph node status was included in 40% of cases, and lymphovascular invasion was not commented on in 97.4% of cases. Only 26% of the tumors had hormone receptors and/or HER2 tested.

CONCLUSION

Some essential histologic parameters were absent from the histologic reports, and where present, a proportion were inaccurate. Attention to specimen fixation and method of grading and familiarity with uncommon breast cancer types are required; all can be facilitated by education and training. The use of a template/proforma is recommended to ensure cancer data set parameters are included in the pathology reports.

A review of preanalytical factors affecting molecular, protein, and morphological analysis of formalin-fixed, paraffin-embedded (FFPE) tissue: how well do you know your FFPE specimen?

CONTEXT

Formalin fixation and paraffin embedding is a timeless, cost-efficient, and widely adopted method of preserving human tissue biospecimens that has resulted in a substantial reservoir of formalin-fixed, paraffin-embedded blocks that represent both the pathology and preanalytical handling of the biospecimen. This reservoir of specimens is increasingly being used for DNA, RNA, and proteomic analyses.

OBJECTIVE

To evaluate the impact of preanalytical factors associated with the formalin fixation and paraffin embedding process on downstream morphological and molecular endpoints.

DATA SOURCES

We surveyed the existing literature using the National Cancer Institute's Biospecimen Research Database for published reports investigating the potential influence of preanalytical factors associated with the formalin fixation and paraffin embedding process on DNA, RNA, protein, and morphological endpoints.

CONCLUSIONS

Based on the literature evidence, the molecular, proteomic, and morphological endpoints can be altered in formalin-fixed, paraffin-embedded specimens by suboptimal processing conditions. While the direction and magnitude of effects associated with a given preanalytical factor were dependent on the analyte (DNA, RNA, protein, and morphology) and analytical platform, acceptable conditions are highlighted, and a summary of conditions that could preclude analysis is provided.

Standardization of Diagnostic Immunohistochemistry: Literature Review and Geisinger Experience

Context

Immunohistochemistry has become an indispensable ancillary technique in anatomic pathology laboratories. Standardization of every step in preanalytic, analytic, and postanalytic phases is crucial to achieve reproducible and reliable immunohistochemistry test results.

Objective

To standardize immunohistochemistry tests from preanalytic, analytic, to postanalytic phases.

Data Sources

Literature review and Geisinger (Geisinger Medical Center, Danville, Pennsylvania) experience.

Conclusions

This review article delineates some critical points in preanalytic, analytic, and postanalytic phases; reiterates some important questions, which may or may not have a consensus at this time; and updates the newly proposed guidelines on antibody validation from the College of American Pathologists Pathology and Laboratory Quality Center. Additionally, the article intends to share Geisinger's experience with (1) testing/optimizing a new antibody and troubleshooting; (2) interpreting and reporting immunohistochemistry assay results; (3) improving and implementing a total immunohistochemistry quality management program; and (4) developing best practices in immunohistochemistry.

The effects of under 6 hours of formalin fixation on hormone receptor and HER2 expression in invasive breast cancer: a systematic review

OBJECTIVES

A systematic review of the literature was performed to identify whether minimum formalin fixation time may be reduced for reliable immunohistochemical assessment of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2).

METHODS

PubMed, EMBASE, and the Cochrane Library were systematically searched for studies addressing effects of brief tissue fixation (<6 hours) on the analysis of ER, PR, or HER2 expression in patients with breast cancer.

RESULTS

Five publications reported effects of brief fixation on ER, PR, or HER2 expression. Four studies showed similar receptor expression of short fixation compared with recommended fixation time (6-72 hours). One publication found that a minimum fixation time of 6 to 8 hours is necessary for reliable ER results.

CONCLUSIONS

Available data on the effect of brief fixation on receptor status are limited. However, brief fixation of very highly expressing breast cancers does not seem to alter ER, PR, and HER2 status. Nevertheless, scoring inconsistencies have been observed. Further research is required in larger study populations with more low-expressing cases for future validation.

Multispectral imaging and pathology: seeing and doing more

BACKGROUND

The current appreciation of the biological complexity of disease has led to increasing demands on pathologists to provide clinically relevant, quantitative morphological and molecular information while preserving cellular and tissue context. This can be technically challenging, especially when signals of interest are colocalized. With fluorescence-based methods, sensitivity and quantitative reliability may be compromised by spectral cross-talk between labels and by autofluorescence. In brightfield microscopy, overlapping chromogenic signals pose similar imaging difficulties.

APPROACH

These challenges can be addressed using commercially available multispectral imaging technologies attached to standard microscope platforms, or alternatively, integrated into whole-slide scanning instruments.

ASSESSMENT

Multispectral techniques, along with other developments in digital analysis, will allow pathologists to deliver appropriate quantitative and multiplexed analyses in a reproducible and timely manner. Caveats apply - as the complexity of the sample preparation and analysis components increases, commensurate attention must be paid to the use of appropriate controls for all stages of the process.

Systematic review on hormone receptor testing in breast cancer

Assessment of hormone receptors (estrogen and progesterone) helps to direct therapy for women with breast cancer. Immunohistochemistry is most commonly used to assess hormone receptor status and it is essential that these tests are performed accurately and reliably within and across laboratories. The overall purpose of this guideline is to improve the quality and accuracy of hormone receptor testing and its utility as a prognostic and predictive marker for invasive and in situ breast cancer. Medline, EMBASE, the Cochrane Database of Systematic Reviews, and abstracts from the San Antonio Breast Cancer Symposium were searched. An environmental scan of the internet and of international guideline developers and key organizations was performed. Preanalytic elements such as the collection, fixation, and storage of samples, and analytic elements such as selection of antibodies and scoring methods that seem to offer the best results for immunohistochemical assessment of hormone receptors are presented. Proficiency testing or quality assurance of immunohistochemistry is described.

Mice with inactivation of aryl hydrocarbon receptor-interacting protein (Aip) display complete penetrance of pituitary adenomas with aberrant ARNT expression

Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene have been shown to predispose to pituitary adenoma predisposition, a condition characterized by growth hormone (GH)-secreting pituitary tumors. To study AIP-mediated tumorigenesis, we generated an Aip mouse model. Heterozygous mice developed normally but were prone to pituitary adenomas, in particular to those secreting GH. A complete loss of AIP was detected in these lesions, and full penetrance was reached at the age of 15 months. No excess of any other tumor type was found. Ki-67 analysis indicated that Aip-deficient tumors have higher proliferation rates compared with Aip-proficient tumors, suggesting a more aggressive disease. Similar to human AIP-deficient pituitary adenomas, immunohistochemical studies showed that expression of aryl hydrocarbon receptor nuclear translocator 1 or 2 (ARNT or ARNT2) protein was lost in the mouse tumors, suggesting that mechanisms of AIP-related tumorigenesis involve aberrant ARNT function. The Aip(+/-) mouse appears to be an excellent model for the respective human disease phenotype. This model constitutes a tool to further study AIP-associated pituitary tumorigenesis and may be potentially valuable in efforts to develop therapeutic strategies to treat pituitary adenomas.

State of the art in antigen retrieval for immunohistochemistry

The masking effects of antigens by chemical fixation, processing, embedding media interactions, represent a serious problem for immunohistochemical purposes. Fortunately, different approaches in antigen retrieval exist. These techniques are relatively recent and continuously expanding. This review focuses on the present state of the art in antigen retrieval methods for immunohistochemistry in light and electron microscopy. Moreover, a brief discussion on the chemical aspects of fixation, mechanism of retrieval, as well as its efficacy, is given.

The effects of fixation, processing and evaluation criteria on immunohistochemical detection of hormone receptors in breast cancer

A task force of the Japanese Breast Cancer Society has proposed a recommendation for adequate evaluation of hormone receptors in routine practice, in order to standardize handling of tissues, staining techniques and scoring systems. As a part of the study, several examinations were conducted to detect the effect of technical problems, including the influence of fixation time and other fixation and processing conditions, on the immunoreactivity for ERalpha. There is little influence of prolonged fixation on the immunoreactivity for ERalpha, except for cases in which particularly over-fixed blocks are used. A delay in the onset of fixation could decrease the immunohistochemical findings of steroid receptors, compared with shorter or longer fixation, and the situation is similar to the fixation of a whole large surgical specimen in formalin in a big bucket. Incomplete fixation might be an important cause of heterogeneiety of immunoreactivity for ERalpha. Manual and automated immunohistochemical (IHC) staining by DAKO (Glostrup, Denmark) and Biogenex (San Ramon, CA) and automated IHC staining by Ventana Medical Systems (Tucson, AZ) each employ different methods. Using a scoring system, in which the proportion of cells stained in each specimen was recorded as 0, less than 1%, 1% or more and less than 10%, and 10% or more, the intermethod variability of those IHC staining methods exhibited substantial multi-rater kappa values concerning the ER and PgR (kappa for ER according to the percentage of positive cells=0.67; PgR=0.72). Concerning intermethod consistency, the scoring system based on the percentage of positive cells was advantageous over other scoring systems, based on the intensity of nuclear staining. Using double staining, patients with ER-positive and HER2-positive tumors can be classified as those with co-expressed tumors and those with differently expressed tumors. As such, the co-expressed tumor might be resistant to antiestrogen therapy in ERalpha-positive and HER2-positive breast cancer and double staining might lead to the development of new therapeutic strategies for hormone and HER2-positive breast cancer.

Recommendations for improved standardization of immunohistochemistry

Immunohistochemistry (IHC) continues to suffer from variable consistency, poor reproducibility, quality assurance disparities, and the lack of standardization resulting in poor concordance, validation, and verification. This document lists the recommendations made by the Ad-Hoc Committee on Immunohistochemistry Standardization to address these deficiencies. Contributing factors were established to be underfixation and irregular fixation, use of nonformalin fixatives and ancillary fixation procedures divested from a deep and full understanding of the IHC assay parameters, minimal or absent IHC assay optimization and validation procedures, and lack of a standard system of interpretation and reporting. Definitions and detailed guidelines pertaining to these areas are provided.

Interstitial Cajal-like cells in human gallbladder

We describe here an interstitial Cajal-like cell type (ICLC) in human gallbladder, resembling the archetypal enteric interstitial cells of Cajal. Gallbladder ICLC were demonstrated in fresh preparations (tissue cryosections) using methylene-blue, and fixed specimens in Epon semi-thin sections stained with toluidine blue or transmission electron microscopy (TEM). The positive diagnosis of gallbladder ICLC was further verified by immunohistochemistry: CD117/c-kit, CD34, and another 16 antigens: vimentin, desmin, nestin, alpha-smooth muscle actin, NK-1, S-100, PGP-9.5, tau protein, chromogranin A, NSE, GFAP, CD1a, CD62-P, CD68, estrogen and progesterone receptors. Double immunostaining was performed for CD117, CD34 and CD117 and nestin, respectively. In fresh specimens, the spatial density of gallbladder ICLC was 100-110 cells/mm(2). ICLC mainly appeared beneath the epithelium and in muscularis (about 7%, and approximately 5%, respectively). In toto, ICLC represent in gallbladder approximately 5.5% of subepithelial cells. TEM showed that diagnostic criteria were fulfilled by ICLC. Moreover, TEM indicated that the main ultrastructural distinctive feature for ICLC, the cell processes, develop into the characteristic shape at a relatively early stage of development. It remains to be established if, in humans, ICLC are involved in gallbladder (dis)functions (e.g. pace-making, secretion (auto-, juxta- and/or paracrine), intercellular signaling, or stone formation).

Optimization of estrogen receptor analysis by immunocytochemistry in random periareolar fine-needle aspiration samples of breast tissue processed as thin-layer preparations

Immunostaining of estrogen receptor alpha (ER) in samples of benign breast tissue obtained by random periareolar fine-needle aspiration (RPFNA) is a practical tool for breast cancer chemoprevention trials. The authors report an optimized method of ER immunostaining for use with thin-layer preparations of modified Cytolyt-fixed benign breast tissue acquired by RPFNA. Samples of benign breast tissue and MCF-7 controls processed as thin-layer preparations were tested for the effects of antibody titer, antigen retrieval temperature (90 degrees or 115 degrees C), buffer (20% nuclear decloaker, pH 9.3; 10 mM citrate buffer, pH 6), and blocking solution (0.01% glucose oxidase or 0.3% H2O2) on ER immunostaining. The prevalence of positively stained breast epithelial cells, mean intensity of ER staining, and composite immunostaining score were evaluated for effect of immunostaining protocol. RPFNA samples and MCF-7 cells processed using nuclear decloaker and low-temperature antigen retrieval had more ER-positive cells (P<0.0001) and increased mean staining intensity and weighted staining indices (P<0.05) compared with samples prepared with citrate buffer and high-temperature antigen retrieval. Glucose oxidase increased ER-positive cells in comparison to hydrogen peroxide (P<0.04) when combined with low-temperature antigen retrieval and the use of nuclear decloaker. Staining was negative for all non-immune controls regardless of protocol. The combination of low-temperature antigen retrieval, diluted commercial nuclear decloaker solution, and a glucose oxidase blocking step yielded optimal ER immunostaining for thin-layer preparations of benign breast tissue harvested by RPFNA.

Novel type of interstitial cell (Cajal-like) in human fallopian tube

We describe here--presumably for the first time--a Cajal-like type of tubal interstitial cells (t-ICC), resembling the archetypal enteric ICC. t-ICC were demonstrated in situ and in vitro on fresh preparations (tissue cryosections and primary cell cultures) using methylene-blue, crystal-violet, Janus-Green B or MitoTracker-Green FM Probe vital stainings. Also, t-ICC were identified in fixed specimens by light microscopy (methylene-blue, Giemsa, trichrome stainings, Gomori silver-impregnation) or transmission electron microscopy (TEM). The positive diagnosis of t-ICC was strengthened by immunohistochemistry (IHC; CD117/c-kit+ and other 14 antigens) and immunofluorescence (IF; CD117/c-kit+ and other 7 antigens). The spatial density of t-ICC (ampullar-segment cryosections) was 100-150 cells/mm2. Non-conventional light microscopy (NCLM) of Epon semithin-sections revealed a network-like distribution of t-ICC in lamina propria and smooth muscle meshwork. t-ICC appeared located beneath of epithelium, in a 10-15 microm thick 'belt', where 18+/-2% of cells were t-ICC. In the whole lamina propria, t-ICC were about 9%, and in muscularis approximately 7%. In toto, t-ICC represent ~8% of subepithelial cells, as counted by NCLM. In vitro, t-ICC were 9.9+/-0.9% of total cell population. TEM showed that the diagnostic 'gold standard' (Huizinga et al., 1997) is fulfilled by 'our' t-ICC. However, we suggest a 'platinum standard', adding a new defining criterion- characteristic cytoplasmic processes (number: 1-5; length: tens of microm; thickness: < or =0.5 microm; aspect: moniliform; branching: dichotomous; organization: network, labyrinthic-system). Quantitatively, the ultrastructural architecture of t-ICC is: nucleus, 23.6+/-3.2% of cell volume, with heterochromatin 49.1+/-3.8%; mitochondria, 4.8+/-1.7%; rough and smooth endoplasmic-reticulum (1.1+/-0.6%, 1.0+/-0.2%, respectively); caveolae, 3.4+/-0.5%. We found more caveolae on the surface of cell processes versus cell body, as confirmed by IF for caveolins. Occasionally, the so-called 'Ca2+-release units' (subplasmalemmal close associations of caveolae+endoplasmic reticulum+mitochondria) were detected in the dilations of cell processes. Electrophysiological single unit recordings of t-ICC in primary cultures indicated sustained spontaneous electrical activity (amplitude of membrane potentials: 57.26+/-6.56 mV). Besides the CD117/c-kit marker, t-ICC expressed variously CD34, caveolins 1&2, alpha-SMA, S-100, vimentin, nestin, desmin, NK-1. t-ICC were negative for: CD68, CD1a, CD62P, NSE, GFAP, chromogranin-A, PGP9.5, but IHC showed the possible existence of (neuro)endocrine cells in tubal interstitium. We call them 'JF cells'. In conclusion, the identification of t-ICC might open the door for understanding some tubal functions, e.g. pace-making/peristaltism, secretion (auto-, juxta- and/or paracrine), regulation of neurotransmission (nitrergic/purinergic) and intercellular signaling, via the very long processes. Furthermore, t-ICC might even be uncommitted bipotential progenitor cells.

Ultrasound-accelerated formalin fixation of tissue improves morphology, antigen and mRNA preservation

Formalin fixation and paraffin embedding are conventional tissue preservation and processing methods used for histologic diagnosis in over 90% of cases. However, formalin fixation has three disadvantages: (1) slow fixation (16-24 h) hinders intraoperative decision making, (2) slow quenching of enzymatic activity causes RNA degradation, and (3) extensive molecule modification affects protein antigenicity. Applying high-frequency, high-intensity ultrasound to the formalin fixative cuts fixation time to 5-15 min. Fixation of various tissues such as lymph node, brain, breast, and prostate suggests that, compared to the conventional method, implementation of ultrasound retains superior and more uniform tissue morphology preservation. Less protein antigenicity is altered so that rapid immunohistochemical reactions occur with higher sensitivity and intensity, reducing the need for antigen retrieval pretreatment. Better RNA preservation results in stronger signals in in situ hybridization and longer RNA fragments extracted from fixed tissues, probably due to rapid inhibition of endogenous RNase activity. Molecules extracted from ultrasound-fixed tissues are of greater integrity and quantity compared to conventionally fixed tissues, and thus better support downstream molecular analyses. Overall, ultrasound-facilitated tissue preservation can provide rapid and improved morphological and molecular preservation to better accommodate both traditional and molecular diagnoses.

Phospho-Akt overexpression in non-small cell lung cancer confers significant stage-independent survival disadvantage

PURPOSE

Akt is a signal transduction protein that plays a central role in inhibiting apoptosis in a variety of cell types including human cancer cells. In cell lines derived from human non-small cell lung cancers (NSCLCs), Akt has been shown to confer chemoresistance by inhibition of apoptosis in response to different chemotherapeutic agents including platinum-based agents, which are often the first-line therapy for NSCLCs. Only 20% to 30% of patients with NSCLC treated with chemotherapy have clinical evidence of response. The purpose of this study is to determine whether or not overexpression of activated Akt [i.e., phosphorylated Akt (pAkt)] is correlated with survival.

EXPERIMENTAL DESIGN

We studied tumors from 61 patients with NSCLC in three tissue microarrays. All patients were followed for a period of 10 years or until death. The arrays were studied immunohistochemically with antibodies against pAkt, p53, and Ki-67.

RESULTS

There was a statistically significant difference in survival between the 14 patients with strong pAkt staining and the 47 patients with weak to absent pAkt staining both by log-rank (P = 0.0416) and Breslow analysis (P = 0.0446). Difference in survival time with respect to pAkt status was also statistically significant even after accounting for stage at diagnosis (P = 0.004). Neither p53 nor Ki-67 was a statistically significant prognostic factor.

CONCLUSIONS

Overexpression of pAkt is an independent prognostic factor. Additional studies of human NSCLCs are warranted to drive the development of targeted tumor-specific antineoplastic therapies.

Tumour-derived TGF-beta1 modulates myofibroblast differentiation and promotes HGF/SF-dependent invasion of squamous carcinoma cells

The development of an altered stromal microenvironment is a common feature of many tumours including squamous cell carcinoma (SCC), and there is increasing evidence that these changes in the stroma, which include increased expression of proteases and cytokines, may actually promote tumour progression. A common finding is that stromal fibroblasts become ‘activated’ myofibroblasts, expressing smooth muscle actin and secreting cytokines, proteases and matrix proteins. We show that myofibroblasts are commonly found in the stroma of oral SCC and are often concentrated at the invasive margin of the tumour. Using oral SCC cells and primary oral fibroblasts, we demonstrate that tumour cells directly induce a myofibroblastic phenotype, and that this transdifferentiation is dependent on SCC-derived TGF-β1. In turn, myofibroblasts secrete significantly higher levels of hepatocyte growth factor/scatter factor compared with fibroblast controls, and this cytokine promotes SCC invasion through Matrigel, a mixture of basement membrane proteins. This is the first time that this double paracrine mechanism has been demonstrated between squamous carcinoma cells and fibroblasts, and emphasises that cancer invasion can be promoted indirectly by the release of tumour-induced host factors from stroma.