Polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma: distinct architectural composition revealed by collagen IV, laminin and their integrin ligands (alpha2beta1 and alpha3beta1)

MicroRNAs expression pattern related to mast cell activation and angiogenesis in paraffin-embedded salivary gland tumors

The aim of this study was evaluate the expression profile of microRNAs related to mast cells activation and angiogenesis in salivary glands tumors.

METHOD

We have analyzed the expression of miR-9, miR-16, miR-17, miR-132, miR-195 and miR-221 by real-time RT-PCR, in 11 adenoid cystic carcinomas, 9 mucoepidermoid carcinomas and 11 pleomorphic adenomas. Immunohistochemical investigation was performed to detect mast cells tryptase and CD-34 for microvessels biomarkers. miR-16, miR-17, miR-132, miR-195 and miR-221 showed a decreased expression, whereas miR-9 showed an increased expression in most cases compared to normal tissues. However, in all tumors studied only miR-9 showed a statistical significant negative correlation with microvessel density (p=0.001). It was observed a higher density of mast cells in mucoepidermoid carcinomas (10.55 cells/mm2) when compared to adenoid cystic carcinomas (6.27 cells/mm2) and between mucoepidermoid carcinomas and pleomorphic adenomas (5.97células/mm2). miR-17, miR-132, miR-195 and miR-221 seem to play an important role as tumor suppressor in salivary gland tumors. In addition, the significant correlation between mast cell and microvessel density contributes to the growth and pathogenesis of these tumors and they may become strong therapeutic targets in the future.

Involvement of PSMD10, CDK4, and Tumor Suppressors in Development of Intrahepatic Cholangiocarcinoma of Syrian Golden Hamsters Induced by Clonorchis sinensis and N-Nitrosodimethylamine

Background

Clonorchis sinensis is a group-I bio-carcinogen for cholangiocarcinoma (CCA). Although the epidemiological evidence links clonorchiasis and CCA, the underlying molecular mechanism involved in this process is poorly understood. In the present study, we investigated expression of oncogenes and tumor suppressors, including PSMD10, CDK4, p53 and RB in C. sinensis induced hamster CCA model.

Methods

Different histochemical/immunohistochemical techniques were performed to detect CCA in 4 groups of hamsters: uninfected control (Ctrl.), infected with C. sinensis (Cs), ingested N-nitrosodimethylamine (NDMA), and both Cs infected and NDMA introduced (Cs+NDMA). The liver tissues from all groups were analyzed for gene/protein expressions by quantitative PCR (qPCR) and western blotting.

Principal Findings

CCA was observed in all hamsters of Cs+NDMA group with well, moderate, and poorly differentiated types measured in 21.8% ± 1.5%, 13.3% ± 1.3%, and 10.8% ± 1.3% of total tissue section areas respectively. All CCA differentiations progressed in a time dependent manner, starting from the 8^th week of infection. CCA stroma was characterized with increased collagen type I, mucin, and proliferative cell nuclear antigen (PCNA). The qPCR analysis showed PSMD10, CDK4 and p16INK4 were over-expressed, whereas p53 was under-expressed in the Cs+NDMA group. We observed no change in RB1 at mRNA level but found significant down-regulation of RB protein. The apoptosis related genes, BAX and caspase 9 were found downregulated in the CCA tissue. Gene/protein expressions were matched well with the pathological changes of different groups except the NDMA group. Though the hamsters in the NDMA group showed no marked pathological lesions, we observed over-expression of Akt/PKB and p53 genes proposing molecular interplay in this group which might be related to the CCA initiation in this animal model.

Conclusions/Significance

The present findings suggest that oncogenes, PSMD10 and CDK4, and tumor suppressors, p53 and RB, are involved in the carcinogenesis process of C. sinensis induced CCA in hamsters.

Clonorchis sinensis is a helminth parasite and a carcinogenic agent for cholangiocarcinoma (CCA) or bile duct cancer in humans. Though a large and compelling body of evidence suggests an association between C. sinensis and CCA, the mechanism underlying at the genetic/proteomic level is little known. To explore the underlying molecular mechanism we investigated a number of genes/proteins in C. sinensis induced hamster CCA model. Here C. sinensis induced CCA successfully in all hamsters when introduced with N-nitrosodimethylamine. The histopathology confirmed the development of CCA and detected excessive collagen fibers, mucin and cell division related protein. The quantitative PCR analysis showed increased levels of oncogenes PSMD10, CDK4 and decreased level of tumor suppressor gene p53. The western blot analysis observed significant decrease of another tumor suppressor called RB protein. Genes/protein expressions were matched well with the pathological changes of CCA hamster. The present study suggests that oncogenes, PSMD10 and CDK4, and tumor suppressors gene p53 and protein RB, are involved in the carcinogenesis process of C. sinensis induced CCA in hamsters.

Adenoid cystic carcinoma of cervix: two cases report and review of the literature

Adenoid cystic carcinoma of the cervix is a rare and aggressive tumor with fatal outcome. In this paper we report two cases of primary adenoid cystic carcinoma and a review of literature. A 80 years old woman, admitted to our hospital with postmenopausal bleeding and hydrorrhea. Gynealogical examination showed a cervical stenotic with the presence of a tumor processus. Biopsy of cervical growth was done. 80-year-old woman presented with vaginal bleeding with pelvic pain. Physical examination revealed a friable mass in the cervix. Incisional biopsy was performed. In the both cases the diagnosis of adenoid cystic carcinoma of the cercix was confirmed. Adenoid cystic carcinoma of the cervix is clinically and radiologically similar to other tumors of the cervix but the diagnosis can only be made by histological examination.

Adenoid cystic carcinoma: An unusual presentation

The adenoid cystic carcinoma is a relatively rare epithelial tumor of the major and minor salivary glands, accounting for about 1% of all malignant tumor of the oral and maxillofacial regions. Peak incidence occurs between the 5^th and 6^th decades of life. The clinical and pathological findings typical of this tumor include slow growth, peri-neural invasion, multiple local recurrences and distant metastasis. Herein, we report a case of adenoid cystic carcinoma of oropharynx with unusual clinical presentation. The diagnosis of this case and importance of cytology in diagnosing such cases is discussed.

Immunohistochemical analysis of laminin expression in adenoid cystic carcinoma

BACKGROUND AND OBJECTIVES

This study aims at the observation of the immunohistochemical expression of laminin in adenoid cystic carcinoma (ACC) of salivary gland origin and to analyze the distribution of laminin in various components of the tumor and correlate the expression of laminin with the growth and differentiation of the tumor.

MATERIALS AND METHODS

THIRTY CASES OF ACC WERE SUBJECTED TO IMMUNOHISTOCHEMICAL STUDY USING POLYCLONAL ANTIHUMAN LAMININ PRIMARY ANTIBODY, DISTRIBUTION OF LAMININ IN EACH CASE OF ACC WAS OBSERVED IN THE FOLLOWING AREAS: Intracellularly, inner borders of the pseudocystic spaces, within the lumen of the pseudocysts, around the tumor islands and in the intervening stroma.

RESULTS

Laminin positivity was observed in the inner aspect of the pseudocystic spaces in 15 cases, within the lumen of pseudocystic spaces in 22 cases, in the intervening stroma in 20 cases, bordering the tumor islands in 16 cases and intracellularly in 4 cases.

INTERPRETATION AND CONCLUSION

Based on these observations, it can be assumed that laminin plays a major role in proliferation of the tumor cells and in pseudocyst formation. Thus, laminin might play a significant role in the growth and differentiation of ACC and also help in assessing the prognosis of the tumor.

Polymorphous low grade adenocarcinoma has a consistent p63+/p40- immunophenotype that helps distinguish it from adenoid cystic carcinoma and cellular pleomorphic adenoma

Polymorphous low grade adenocarcinoma (PLGA) is a tumor of minor salivary glands that exhibits considerable morphologic overlap with adenoid cystic carcinoma and cellular pleomorphic adenoma, especially in small biopsy specimens. Unlike these other tumor types. PLGAs do not harbor a myoepithelial component, yet their frequent positivity for p63 diminishes the usefulness of this particular myoepithelial marker as a discriminating immunostain. p40 is an antibody that recognizes ΔNp63, a p63 isoform that is more specific for true myoepithelial differentiation. As such, p40 immunostaining could help distinguish PLGAs from adenoid cystic carcinomas and pleomorphic adenomas. In this study, p63 and p40 immunohistochemistry was performed on paraffin embedded, formalin fixed tissue from 11 PLGAs, 101 adenoid cystic carcinomas, and 31 pleomorphic adenomas. All 11 PLGAs (100 %) were positive for p63 but completely negative for p40. Among adenoid cystic carcinomas, 91 of 101 (90 %) were positive for p63 and 90/101 (89 %) were positive for p40. The single discordant p63+/p40- adenoid cystic carcinoma exhibited solid architecture and high grade features not typically seen in PLGA. Among pleomorphic adenomas, 21/31 (68 %) were positive for p63 and 13/31 (42 %) were positive for p40. For the pleomorphic adenomas, the discordant p63+/p40- staining pattern was seen only in the overtly mesenchymal chondromyxoid stroma. The cellular epithelial component of the pleomorphic adenomas demonstrated concordant p63+/p40+ or p63-/p40- immunophenotypes. PLGA consistently exhibits a p63+/p40- immunophenotype that can help distinguish it from adenoid cystic carcinoma and cellular pleomorphic adenoma, tumors that characteristically demonstrate concordant p63 and p40 immunostaining patterns. A p63/p40 immunohistochemical panel can provide a valuable tool for making the distinction between these morphologically similar but clinically divergent entities.

Polymorphous low-grade adenocarcinoma: an analysis of epidemiological studies and hints for pathologists

Background

This study is an analysis of the prevalence of polymorphous low grade adenocarcinoma (PLGA) in epidemiological surveys of salivary tumors published in the English language from 1992 to 2012.

Methods

These surveys included studies from different researchers, countries and continents. The 57 surveys for which it was possible to calculate the percentage of PLGAs among all malignant minor salivary gland tumors (MMSGT) were included in this review.

Results

The statistical analyses show significant differences in the PLGA percentage by time period, country and continent in the studies included in this review. The percentage of PLGAs among MMSGTs varied among the studies, ranging from 0.0% to 46.8%. PLGA rates have varied over the period studied and have most recently increased. The frequency of reported PLGA cases also varied from 0.0% to 24.8% by the country in which the MMSGT studies were performed. The PLGA percentages also varied significantly by continent, with frequencies ranging from 3.9% in Asia to 20.0% in Oceania

Conclusion

Based on these results, we concluded that although the accuracy of PLGA diagnoses has improved, they remain a challenge for pathologists. To facilitate PLGA diagnoses, we have therefore made some suggestions for pathologists regarding tumors composed of single-layer strands of cells that form all of the histological patterns present in the tumor, consistency of the cytological appearance and uniformly positive CK7, vimentin and S100 immunohistochemistry, which indicate a single PLGA phenotype.

Virtual slide

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1059098656858324

Immunoexpression of α2β1, α3β1, and α5β1 integrins in pleomorphic adenoma and adenoid cystic carcinoma

The aim of the present study was to compare the expression of α2β1, α3β1, and α5β1 integrins between 28 pleomorphic adenomas (PAs) and 10 adenoid cystic carcinomas (ACCs), and investigate differences in the expression of these integrins according to histologic subtypes of ACCs. It was taken into consideration the presence or absence, distribution, and localization of integrin immunoexpression. There was immunoreactivity in the intercellular contacts of the strands, nests, and solid sheets of PAs, as well as in the luminal and nonluminal cells of the duct-like structures, with a predominant immunoexpression in the luminal cells. The immunoexpression in ACCs varied with histologic subtype of the tumor. It was verified for a tendency of absence and/or reduced expression of all integrins in the solid subtype of ACCs. In general, PAs revealed a more diffuse and remarkable immunoexpression of all studied integrins than ACCs. The reduced integrins expression in ACC may be related to a lesser degree of cell differentiation in this neoplasm. Moreover, the absence and/or reduced expression of the studied integrins in solid ACC suggest a possible role in pathogenesis and more aggressive biological behavior of this histologic subtype.

Secretion of collagen I and tenascin is modulated by laminin-111 in 3D culture of human adenoid cystic carcinoma cells

Adenoid cystic carcinoma is a frequent malignant salivary gland neoplasm with high levels of recurrence and metastasis. This neoplasm expresses prominent extracellular matrix (ECM). We are studying regulatory mechanisms underlying secretion of ECM molecules in adenoid cystic carcinoma. We have previously demonstrated that laminin modulates the phenotype of a human adenoid cystic carcinoma (CAC2) cell line. Thus, this molecule would be a good candidate to regulate secretion of ECM molecules in these cells. Here we analysed the role played by laminin-111 [formerly laminin-1; Aumailley et al. (2005). Matrix Biol. 24, 326] stimulating secretory activity of CAC2 cells. Three-dimensional cultures of cells in laminin-111 (treated) or agarose (controls) were studied by light and electron microscopy. Ultrastructural analysis of CAC2 cells grown within laminin-111 showed pseudocysts filled with secretory-like material. Cells exhibited prominent and dilated endoplasmic reticulum and coated and uncoated vesicles. Ultrastructural findings suggested that laminin-111 induced secretory activity in CAC2 cells. We further investigated this point by light microscopy, immunofluorescence and confocal microscopy. Histochemistry showed periodic acid-Schiff (PAS)-positive diastase-resistant material in CAC2 cells treated by laminin-111. This material could represent laminin-induced secretion of ECM molecules. We searched for collagen I and tenascin in CAC2 cells treated by laminin-111. Confocal microscopy and immunoblot showed that laminin-111 enhanced secretion of collagen I and tenascin in CAC2 cells. We suggest that laminin-111 modulates secretion of collagen I and tenascin in cells derived from human adenoid cystic carcinoma.

Expression of beta-1 integrin in human developing salivary glands and its parallel relation with maturation markers: In situ hybridisation and immunofluorescence study

BACKGROUND AND OBJECTIVE

Salivary gland development entails co-ordinated processes involving complex molecular interactions in which integrins have a fundamental role. The integrins are a family of heterodimeric transmembrane receptors comprising alpha and beta subunits that mediate intercellular and extracellular signals involved in the organisation of cells in tissues and organs during development. The beta-1 integrin in particular have been implicated in proliferation and differentiation of cells involved in the development of epithelial tissues. To understand the role of beta-1 integrin in salivary gland development we have studied its expression in human foetal tissues.

DESIGN

In situ hybridisation was used to compare the expression and localisation of integrin beta-1 with differentiation markers in developing human salivary glands obtained from foetuses of 8-24 weeks gestation.

RESULTS

Integrin beta-1 first appeared during bud stage in a few cells and its distribution increased as salivary gland morphogenesis progressed. This increased pattern of beta-1 integrin expression was coincident with the appearance of the differentiation markers CK14, CK low MW and smooth-muscle actin.

CONCLUSIONS

The developmentally regulated expression of integrin beta-1 in association with the establishment of a mature phenotype indicated by salivary gland tissue differentiation markers is suggestive of its role in salivary gland morphogenesis.

SIKVAV, a laminin alpha1-derived peptide, interacts with integrins and increases protease activity of a human salivary gland adenoid cystic carcinoma cell line through the ERK 1/2 signaling pathway

Adenoid cystic carcinoma is a frequently occurring malignant salivary gland neoplasm. We studied the induction of protease activity by the laminin-derived peptide, SIKVAV, in cells (CAC2) derived from this neoplasm. Laminin alpha1 and matrix metalloproteinases (MMPs) 2 and 9 were immunolocalized in adenoid cystic carcinoma cells in vivo and in vitro. CAC2 cells cultured on SIKVAV showed a dose-dependent increase of MMP9 as detected by zymography and colocalization of alpha3 and alpha6 integrins. Small interfering RNA (siRNA) knockdown of integrin expression in CAC2 cells resulted in decreased adhesion to the peptide. SIKVAV affinity chromatography and immunoblot analysis showed that alpha3, alpha6, and beta1 integrins were eluted from the SIKVAV column, which was confirmed by mass spectrometry and a solid-phase binding assay. Small interfering RNA experiments also showed that these integrins, through extracellular signal-regulated kinase (ERK) 1/2 signaling, regulate MMP secretion induced by SIKVAV in CAC2 cells. We propose that SIKVAV increases protease activity of a human salivary gland adenoid cystic carcinoma cell line through alpha3beta1 and alpha6beta1 integrins and the ERK 1/2 signaling pathway.

Galectin-3 immunoprofile in adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma of salivary glands

Adenoid cystic carcinoma (ACC) and polymorphous low-grade adenocarcinoma (PLGA) are malignant neoplasms of salivary glands, which are similar in histologic patterns but very different in clinical behavior, treatment and prognosis. Galectin-3 is a multifunctional protein of a growing family of beta-galactoside-binding animal lectins, which is implicated in a variety of biological events such as tumor cell adhesion, proliferation, differentiation and angiogenesis. This protein was found to be implicated in cellular transformation and a correlation between its expression and cancer progression and metastasis has been described. The aim of this study was to determine the galectin-3 immunoprofile in 14 cases of ACC (2 cases of tubular subtype, 4 cases of solid subtype and 8 cases of cribriform subtype) and in 12 cases of PLGA with different histologic patterns, including lobular, tubular and cribriform aspects. Moreover, slides of normal salivary glands were included. In normal salivary glands there was strong nuclear and cytoplasmic staining for galectin-3 in ductal luminal cells. ACC showed specific staining in luminal cells mainly in the nuclei. In the tubular subtype of ACC, galectin-3 strongly stained luminal cells of the ductiform structures. The cribriform and solid subtypes showed a few positive luminal cells of small ducts present in the cribriform structures and in solid nests respectively. In the cases of PLGA, independent of the histologic architecture, all tumor cells revealed a positive cytoplasmic reaction. Galectin-3 expression seems to be related to cell differentiation more than to tumor progression and prognosis in the neoplasms studied.

Pleomorphic adenoma and adenoid cystic carcinoma: in vitro study of the impact of TGFbeta1 on the expression of integrins and cytoskeleton markers of cell differentiation

Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) are the commonest benign and malignant salivary gland tumours respectively. Interactions between cells and extracellular matrix of PA and ACC, partially mediated by integrins, are important in their biology. The expression of integrins is regulated by numerous factors, amongst them, transforming growth factor beta1 (TGFbeta1). Our study investigated the effects of TGFbeta1 on the expression of integrin beta subunits in vitro and on the expression of cytoskeletal proteins of cells derived from PA and ACC. The expression of cytoskeletal differentiation markers and integrins was assessed using immunofluorescence. ELISA assays were employed to quantitate the expression integrins and MTT assays evaluated the mitochondrial activity of cells stimulated with TGFbeta1. PA cells showed increased expression of integrins and de novo expression of differentiation markers upon TGFbeta1 stimulation. ACC cells were less responsive to such stimulation. This may reflect important differences in the biological behaviour of benign and malignant cells.

Malignancy-related 67kDa laminin receptor in adenoid cystic carcinoma. Effect on migration and beta-catenin expression

Adenoid cystic carcinoma is a malignant salivary gland neoplasm with recurrence and metastasis. We studied the expression of a malignancy-related non-integrin laminin receptor, the 67LR, in this neoplasm. Immunohistochemistry showed 67LR in adenoid cystic carcinoma. This receptor binds a sequence of laminin beta1 chain, the YIGSR peptide. We studied the effect of 67LR and YIGSR in cells (CAC2) from adenoid cystic carcinoma. Three-dimensional cultures of cells embedded into either laminin-111 gel (controls) or YIGSR-enriched laminin-111 (treated) were prepared and studied by light microscopy. CAC2 cells treated with YIGSR appeared fibroblast-like, while control cells were epithelioid. Blockage of 67LR by antibody abolished YIGSR effect in three-dimensional cultures. We analysed the relevance of 67LR and YIGSR on beta-catenin expression in CAC2 cells. Immunofluorescence and immunoblot showed that YIGSR decreased beta-catenin, while blockage of 67LR restored the presence of this molecule. The 67LR and YIGSR induced fibroblast-like morphology in CAC2 cells, with disruption of cell-cell contacts and decrease of beta-catenin. These features resemble epithelial-mesenchymal transition (EMT). EMT also increases cell migration. In monolayer assays YIGSR increased migration of CAC2 cells. We conclude that 67LR and YIGSR are involved in epithelial-mesenchymal transition, modulation of beta-catenin expression, and migratory activity of CAC2 cells.

Expression of laminin 5 basement membrane components in invading and recurring adenoid cystic carcinoma of the head and neck

OBJECTIVE

Adenoid cystic carcinoma (ACC) of the head and neck grows slowly with structural differentiation, however, this tumor nevertheless also shows a highly invasive potential and a high recurrence rate. Extracellular matrices have been suggested to play an important role in the differentiation and growth of ACC. The aim of this study is to understand the roles of laminin 5 basement membrane (BM) components, including collagen IV and laminin gamma2 for the high degree of invasiveness and the recurrence of ACC.

METHODS

Collagen IV and laminin gamma2 were immunohistochemically localized in tissue sections from nine patients with ACCs.

RESULTS

Cribriform structures with pseudocysts were preserved in small invading tumor nests, and the expression of both of collagen IV and laminin gamma2 was observed in the inner border of the pseudocysts and the surrounding area of the tumor nests. In areas of perineural invasion, the BM components continued to be expressed around the long tumor nests. Recurrent tumors consisted of multiple small nests with a few tumor cell layers, and the expression of the BM components was observed on both the inside of the inner tumor cells and the outside of the outer tumor cells, which was an obviously different appearance from that of the primary tumor.

CONCLUSION

ACC appears to possibly grow and invade using the laminin 5 BM matrices while also preserving their differentiated architecture. The laminin 5 BM matrices might play an important role not only in the differentiation and growth, but also in the invasion and recurrence of ACC of the head and neck.

Integrin expression in developing human salivary glands

The development and complete differentiation of salivary glands is a complex process that involves a large number of co-ordinated events. Little is known about the molecular basis for salivary gland development. However, we have reported previously that integrins appear to play a role. Integrins are heterodimeric transmembrane receptors consisting of one alpha and one beta subunit that play a pivotal role in the interaction of cells with the extracellular matrix. Such interactions regulate the organisation of cells of tissues and organs during development as well as cell proliferation and differentiation. Using immunohistochemistry and Western and Northern blot analysis, we mapped the localisation and expression of integrins beta1, beta3 and beta4 in human salivary glands obtained from foetuses ranging from weeks 4-24 of gestation and compared it with adult salivary glands. Integrin beta1 first appeared during the canalisation stage and during the differentiation stage. A message first appeared at week 6 of development. The expression of beta4 integrin protein and message was observed only in the late stage of differentiation. Integrin beta3 was not detected in the developing glands; however, integrins beta1, beta3 and beta4 were all expressed in adult salivary gland tissues. The data suggest that integrins, particularly beta1, have a role to play in salivary gland development and differentiation.

Expression patterns of integrins on pleomorphic adenoma and adenoid cystic carcinoma: study on specimens and in vitro investigation of the effects of extracellular matrix on the expression of these adhesion molecules

BACKGROUND

Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) are neoplasms of distinct behaviour, showing similar origin, cell components and marked presence of extracellular matrix (ECM). Interactions between cells and ECM are important in the biology of tumours, being partially mediated by integrins. This study investigated these interactions on PA and ACC using paraffin-embedded tissue and an in vitro model of these conditions.

METHODS

Expression of integrins in paraffin-embedded samples was assessed by immunohistochemistry. Cells from PA and ACC were characterized using immunofluorescence, and integrin patterns of expression were investigated on cells cultivated on different ECM proteins.

RESULTS

Luminal cells of both PA and ACC were more intensely positive for integrins than myoepithelial cells. In vitro studies revealed that PA cells expressed more integrins than ACC cells regardless the ECM protein present.

CONCLUSIONS

This study revealed particular patterns of integrin expression in both specimens and in vitro models of PA and ACC. This might prove useful for a better understanding of the biology of these lesions.

Laminin-1 and SIKVAV a laminin-1-derived peptide, regulate the morphology and protease activity of a human salivary gland adenoid cystic carcinoma cell line

In a previous paper, we demonstrated that laminin-1 and its derived peptide SIKVAV modulates the morphology of an adenoid cystic carcinoma cell line (CAC2 cells). Light microscopy of CAC2 cells grown in three-dimensional preparations of SIKVAV-enriched laminin-1 showed the presence of pseudocystic spaces. Pseudocysts are hallmarks of adenoid cystic carcinoma in vivo. We hypothesized that these pseudocystic spaces could be due to the protease-inducing/activating role of SIKVAV. Thus, we studied the presence of matrix metalloproteinases (MMPs) in CAC2 cells treated either by laminin-1 or by SIKVAV-enriched laminin-1. Immunohistochemistry and zymography suggested that SIKVAV enhanced the secretion of MMP-2 and MMP-9 in CAC2 cells. We propose that SIKVAV induces pseudocystic formation probably through the secretion of MMPs 2 and 9.

Extracellular material in adenoid cystic carcinoma of the salivary glands: A comparative cytological study with other salivary myoepithelial tumors

The objective of this study was to clarify extracellular materials (ECMs) in adenoid cystic carcinoma (AdCC) and compare these to those found in other salivary gland tumors with myoepithelial differentiation. The ECM was examined with Papanicolaou, May-Grünwald-Giemsa (MGG), and alcian blue stain at pH 2.5. The ECM in AdCC was classified into three types according to their staining patterns: clear, hyalinized, and membrane type. The incidence of clear-type globule material with magenta on MGG was low in other salivary gland tumors with myoepithelial differentiation. The ECM was identified in other salivary gland tumors with myoepithelial differentiation. However, AdCC has the greatest variety of ECM. These findings are useful to understand the character of AdCC and differential diagnosis of the other salivary gland tumors with myoepithelial differentiation.

A study of the extracellular matrix in salivary gland tumors

BACKGROUND

Epithelial-mesenchymal interactions constitute fundamental phenomena in the development and maintenance of the characteristic branching pattern seen in salivary glands. This study was undertaken to discuss the extracellular matrix (ECM) role in morphogenesis and cellular differentiation of salivary gland tumors originating from the intercalated duct.

METHODS

The ECM components, laminin (LN), type IV collagen, fibronectin (FN), and tenascin (TN) were revealed using a streptoavidin-biotin immunohistochemical technique and analyzed in 34 cases of salivary gland tumors: pleomorphic adenoma (PA); myoepithelioma; basal cell adenoma (BCA); polymorphous low grade adenocarcinoma (PLGA); and adenoid cystic carcinoma (ACC).

RESULTS

LN and type IV collagen were present in all tumors, confining well-organized duct-like structures, separating them from the stroma, or surrounding cell clusters. In PA and myoepithelioma, the basement membrane (BM) fragmentation was observed through LN and type IV collagen staining around each individual spindle-shaped cell, which was strictly related to the cell modification. Interestingly, BM interruption could not be seen in the malign tumors, however, was frequently augmented in some cases. LN, type IV collagen, and FN were also found in the stroma of all tumors studied, except for the pseudocystic spaces of ACC, which were only delimited by replicated LN and type IV collagen. TN exhibited a variable expression, being more intense in solid ACC.

CONCLUSIONS

LN and type IV collagen were always present around morphologically well-differentiated duct-like structures in all tumors studied. BM interruption could not be seen in the malign tumors, on the contrary BM production was evident, which is probably related to invasion. FN was present in the stroma of all tumors, but TN was mostly observed in less differentiated and higher degree of malignancy tumors, such as solid ACC.

Salivary gland tumours: immunoexpression of integrins beta 1, beta 3 and beta 4

BACKGROUND

Integrins, heterodimeric transmembranic adhesion molecules composed of alpha and beta subunits, have been implicated in normal and neoplastic biological processes. We investigated the patterns of expression of integrins subunits beta 1, beta 3 and beta 4 in neoplasms derived from the terminal segment of salivary glands in order to understand their expression patterns in the different structures of these tumours.

METHODS

Immunohistochemistry using 'catalized signal amplification' (CSA) detection system was applied to paraffin-embedded specimens of polymorphous low-grade adenocarcinoma, adenoid cystic carcinoma and acinic cell carcinoma. Normal salivary glands were used as controls.

RESULTS

Immunoexpression of integrins showed that neoplastic structures of the tumours studied tend to mimic the patterns seen in the normal structures of salivary glands from which they are derived. Anaplastic cells were negative for all integrins.

CONCLUSIONS

This study revealed detailed topography of integrins in malignant tumours derived from intercalated acinar segment of salivary gland and this might be useful in the diagnosis of these lesions, especially of fine-needle aspiration (FNA) products or small specimens derived form incisional biopsies.

Polymorphous low-grade adenocarcinoma of the vulva and vagina: a tumor resembling adenoid cystic carcinoma

We report the first case of a polymorphous low-grade adenocarcinoma (PLGA) occurring in the vulva and vagina of a 32-year-old woman. This tumor consisted of cellular lobules with distinct cribriform, papillary, and cystic patterns. Owing to its location and its distinct cribriform pattern, this lesion was initially diagnosed as an unusual variant of adenoid cystic carcinoma (ACC). However, this diagnosis was revised to PLGA when it was recognized that the cribriform, papillary and cystic patterns and their concomitant occurrence in the same lesion are characteristic of PLGA. PLGA should be added to the differential diagnosis of vulvar and vaginal neoplasia.