Hepatocellular carcinoma: expression of basement membrane glycoproteins. An immunohistochemical approach

The identification and characterization of collagenous and non-collagenous glycoproteins have made it possible to use specific antibodies as tools for the topographical localization of the various connective tissue components, and thus to follow the progression of parenchymal-stromal interactions. This investigation is an approach to the study of in vivo relationships between basement membrane components (type IV collagen, laminin) and neoplastic cells of hepatocellular carcinoma. Ten cases of hepatic carcinomas were analysed and paraffin-embedded sections were immunostained with anti-laminin and anti-type IV collagen antibodies. The avidin-biotin-peroxidase complex technique was used. In well differentiated neoplasms with hepatic tumour cells organized in a trabecular pattern lined by sinusoid structures, type IV collagen was always detected at the sinusoidal level. Laminin was evident only in two cases with a prominent intraparenchymal vascular bed. In less differentiated neoplasms, sinusoids were almost absent and only large tumour vessels were positive for both laminin and type IV collagen. At the interface between tumour tissue and the surrounding stroma, some carcinomatous elements were surrounded by laminin and type IV collagen. Our data further support the hypothesis that basement membrane phenotypic expression may be influenced both by the degree of tumour differentiation and by the characteristics of the micro-environment.     

Basement membrane proteins in the spleen: immunohistochemical demonstration and relation to reticulin

In the present study immunohistochemical staining has shown that the ring fibres of the human spleen contain the major basement membrane components, type IV collagen and laminin. The superiority of immunohistochemical methods in demonstrating basement membrane material in the spleen is emphasized. The results are compared with the demonstration of reticular fibres by Gomori's reticulin stain. The findings provide further information about the relationship between basement membrane material and reticular fibres in human spleen. The nature of splenic ring fibres is discussed in the light of the scientific literature.     

Alveolar basement membrane breaks down in diffuse alveolar damage: An immunohistochemical study

Sequential structural changes of the alveoli in diffuse alveolar damage (DAD) were examined by immunohistochemical methods. Lung specimens obtained at autopsy from 52 patients with DAD were stained with antibodies to laminin, 7S collagen (7S) and type IV collagen (type IV) for alveolar basement membrane, to von Willebrand factor, CD-31 and thrombomodulin (TM) for the alveolar capillary endothelial cell, and to epithelial membrane antigen and surfactant apo-protein (PE-10) for the alveolar epithelium. Forty-two of the patients had the exudative form of DAD; 10 of the patients had the proliferative form of DAD. The results were summarized as follows: (i) laminin was most easily impaired both in the epithelial and capillary basement membrane in the early exudative stage; (ii) following laminin, 7S and type IV in the capillary basement membrane were also injured in the early exudative stage, and recovered in the proliferative stage; (iii) subsequently, 7S and type IV in the epithelial basement membrane were also impaired in the late exudative stage, and remained impaired even in the proliferative stage; and (iv) alveolar epithelium regenerated almost completely in the late exudative stage, but staining for TM in the alveolar capillary recovered in the proliferative stage. Because the alveolar basement membrane must govern the homeostasig of alveolar tissue architecture, it was concluded that its preservation is necessary to avoid the abnormal remodeling of the alveoli in the reparative stage of DAD, if the patient survives the acute episodes of the disease.     

Differential basement membrane composition in multiple epithelioid haemangioendotheliomas of liver and lung

We report a case of epithelioid haemangioendothelioma involving both lung and liver. The tumour cells were positive for factor-VIII-related antigen. Immunohistochemical analysis of various basement membrane components in tumour tissue of lung and liver showed striking differences. In the liver tumour there was selective expression of collagen IV, with minimal and focal amounts of laminin and basement membrane-associated heparan sulphate proteoglycan. In the lung tumour nodules, in contrast, all these basement membrane components were present. These patterns of basement membrane expression closely resemble those of normal liver and lung basement membrane respectively. We suggest that this provides evidence that epithelioid haemangioendothelioma arises from local endothelial cell proliferation and that it supports the assumption of a multicentric rather than metastatic origin when multiple tumour deposits are found.     

Immunohistochemical localization of basement membrane type VII collagen and laminin in neoplasms of the head and neck

The distribution pattern of the basement membrane components type VII collagen and laminin, was studied immunohistochemically in normal human head and neck tissues and in a series of benign and malignant tumours from the same site. Using monoclonal antibodies, a basement membrane containing type VII collagen and laminin could be demonstrated beneath the epithelial cell layer in 16 normal head and neck tissues from different localizations. Unlike type VII collagen, laminin was also abundantly present around blood vessels and muscle fibres. With respect to 42 squamous cell carcinomas studied, type VII collagen and laminin were present in basement membranes surrounding small and large tumour fields, independent of the tumour grade. Type VII collagen was demonstrated in the cytoplasm of tumour cells in 36% of the cases, while the antibody to laminin displayed a basement membrane staining pattern mainly. Both antibodies showed a staining gradient in more than half of the cases, with strong staining in the centre of the tumour and weakening of the staining towards the tumour periphery. In a series of 22 salivary gland tumours consisting of 19 pleomorphic adenomas and three adenoid cystic carcinomas, the distribution pattern of type VII collagen and laminin was very heterogeneous. Laminin was present in 17 and type VII collagen in 10 of 19 cases of pleomorphic adenoma, mostly scattered throughout the tumour fields. In the tumours positive for type VII collagen areas with little or no positivity were also found. A correlation between type VII collagen positivity and the presence of basal cell keratin 14 positivity was noticed in the majority of cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Alterations in expression of basement membrane proteins during tumour progression in oral mucosa

Expression of three basement membrane proteins—collagen IV, laminin and fibronectin—was studied in normal, hyperplastic, dysplastic and neoplastic conditions of the oral mucosa using immunohistochemistry. Collagen IV and laminin exhibited similar staining patterns, while fibronectin showed a different pattern of expression. The expression of collagen IV and laminin also demonstrated an inverse correlation between staining intensity, thickness and basement membrane continuity in various stages of tumour progression. In contrast to the continuous and intense staining of basement membrane in normal oral mucosa with collagen IV and laminin antibodies, severe dysplasia and carcinoma exhibited discontinuous, thin and weakly stained basement membrane. The expression of fibronectin showed a direct correlation with extent of tumour progression. In normal mucosa, expression of fibronectin was almost absent, whereas in carcinoma intense expression of fibronectin was evident in the basment membrane and basal cells. These results emphasize the value of basement membrane proteins as biological markers for assessing oral carcinogenesis.     

Distribution of basement membrane laminin and type IV collagen in human reactive lymph nodes

The location of two basement membrane components, laminin and the 7-S domain of type IV collagen, was studied in human lymph nodes using the peroxidase-antiperoxidase method. Basement membrane antigens were present on the walls of blood vessels and of marginal, trabecular and medullary sinuses. Thin, fragmented fibre-like staining was present also in parenchyma outside the germinal centres, in a pattern overlapping with reticular fibres as seen on conventional reticulin stains. This finding suggests that basement membrane components are a part of the reticular fibres of lymph nodes, or are closely associated with them.     

Metastatic chordoma of the breast: an extremely rare lesion mimicking mucinous cancer

Metastases in the breast are rare, with metastatic chordoma being one of the rarest. To our knowledge, only one such case has previously been published in the literature. We report a case of a 74-year-old woman who presented with a palpable lump in her right breast. The lump was mammographically suggestive of mucinous breast cancer because it was a solitary, small, circular, and moderately dense lesion yielding abundant mucoid aspirate. The tumor resembled mucinous carcinoma upon histologic and immunohistochemical examination: it had a mucinous stroma, and the tumor cells strongly expressed epithelial markers. However, the patient had previously undergone surgery for a recurrent sacral chordoma. In addition to the clinical history, the presence of typical physaliferous cells expressing neither estrogen receptors nor cytokeratin 7, but staining positively for S-100 protein, allowed the proper diagnosis. Although extremely rare, metastatic chordoma may represent a challenge in the differential diagnosis of breast lesions. Discriminating metastases of mucin-producing tumors in the breast from primary mucinous carcinomas is important with regard to the striking difference in prognosis of these lesions.     

Loss of basement membrane components laminin and type IV collagen parallels the progression of oral epithelial neoplasia

Aims : To determine the immunohistochemical localization of basement membrane components laminin and type IV collagen in premalignant and malignant lesions of the oral epithelium.  

Methods and results

Formalin-fixed tissue sections of 12 epithelial hyperplasias with no dysplasia and 30 dysplasias, clinically diagnosed as leukoplakia and/or erythroplakia, as well as 50 invasive squamous cell carcinomas, were stained with mouse monoclonal antibodies to human laminin and type IV collagen. Statistical analysis showed that there was a linear trend for discontinuous distribution of laminin from epithelial hyperplasia to epithelial dysplasia and invasive squamous cell carcinoma ( P  < 0.001). Laminin staining showed a linear trend for discontinuity with increasing grade of dysplasia ( P  < 0.05) and was more frequently discontinuous in areas of deep tumour invasion than in central or superficial areas ( P  < 0.05). Brush-shaped thickening and reduplication of the basement membrane were also identified.  

Conclusions

Alterations in the distribution of laminin and type IV collagen in oral premalignant and malignant lesions indicate that the loss of continuity of the subepithelial basement membrane parallels the progression of the neoplastic transformation process in oral epithelium.     

Quantitative assessment of basement membranes in soft tissue tumours. Computerized image analysis of laminin and type IV collagen

Basement membranes (BMs) in 201 soft tissue tumours were quantified using computerized image analysis of tissues immunostained for laminin and type IV collagen. The purpose of the study was to compare and quantify the extent of BM deposition in a large and varied group of benign and malignant tumours. Laminin and type IV collagen gave similar results. The difference between benign and malignant was statistically highly significant (P=0·0001), with greater deposition in benign tumours. BM deposition was homogeneous in benign tumours and heterogeneous in sarcomas and appeared to correlate with the degree of differentiation. Some poorly differentiated sarcomas showed cytoplasmic laminin staining but little or no extracellular BM. Immunohistochemical evaluation of BM has some advantages over electron microscopy; specialized equipment is not needed and since large samples can be studied with little sampling error, heterogeneity can be studied more readily. Subjective visual assessment gives a good overall indication of the extent of BM deposition and in many situations is likely to be a suitable alternative to image analysis. Because of staining heterogeneity, BM immunohistochemistry is unlikely to be of significant value in the diagnosis of specific types of sarcoma. © 1998 John Wiley & Sons, Ltd.     

A comparison of antibodies to type VII and type IV collagen laminin and amnion as epidermal basement membrane markers

We have compared four monoclonal antibodies which label basement membrane components using an indirect immunoperoxidase method in frozen sections of skin biopsies. The antibodies LH 7.2 and GB3 showed expression limited to epidermal and adnexal basement membrane. Antibodies to laminin and type IV collagen also decorated dermal blood vessels and stromal components. The antibodies LH 7.2 and GB3 are more suitable for labelling epidermal basement membrane in the study of cutaneous lesions.     

Immunohistochemical localization of macromolecules of the basement membrane and the peritumoral stroma in human laryngeal carcinomas

Forty laryngeal carcinomas were studied by immunofluorescence with specific antisera against components of the basement membrane (type IV collagen and laminin) as well as antisera against connective tissue antigens (type V collagen and fibronectin). The basement membrane surrounding well-differentiated squamous cell carcinomas showed an appearance similar to that seen beneath normal epithelium. In contrast, marked alterations of the basement membrane were constantly observed around infiltrating and poorly-differentiated carcinomas. The staining of connective tissue components in most cases was as intense in carcinomas as in normal laryngeal mucosa. The use of antibodies to basement membrane components may help to elucidate the mechanism of invasion of connective tissues by malignant cells.     

Changes in vascular basement membrane in the endometrium of Norplant users

Progestogen-only contraception is almost invariably associated with changes in menstrual bleeding patterns. Changes in the endometrial vasculature, and in particular an increase in vascular fragility, may contribute to this bleeding. In this study, endometrial vascular density and endothelial cell basement membrane components were examined using immunohistochemistry before and after insertion of Norplant. Endometrial vascular density was increased from a mean (+/- SEM) of 189.6 +/- 7.0 vessels/mm2 during the control cycle to 253.9 +/- 80.7 vessels/mm2 at 2-13 weeks of Norplant exposure, and to 212.7 +/- 12.9 vessels/mm2 at 14-42 weeks. During the control cycle, a mean of 161.4 +/- 4.5 vessels/mm2 stained for collagen IV (85% of all vessels), while at 2-13 weeks, 144.5 +/- 13.0 vessels/mm2 stained for collagen IV (57% of all vessels) (t ratio = 2.08, P = 0.0057). By 14-42 weeks, 71% of vessels (151.0 +/- 9.8) vessels/mm2 were surrounded by collagen IV. This was not significantly different from control values (t ratio = 2.03). Endometrial vascular laminin was also reduced following Norplant insertion, from a mean of 176.0 +/- 4.2 vessels/mm2 in the control cycle (93% of vessels), to 156.3 +/- 6.7 vessels/mm2 at 2-13 weeks of exposure (57% of vessels) (t ratio = 2.08, P = 0.01). By 14-42 weeks of exposure to Norplant, 162.5 +/- 9 vessels/mm2 (76%) stained for laminin. This was not significantly different from control values (t ratio = 2.04). Endometrial vascular heparan sulphate proteoglycan (HSPG) was reduced from 58.6 +/- 3.0 vessels/mm2 during the control cycle (31% of vessels) to 43.6 +/- 5.6 vessels/mm2 (only 17% of vessels) at 2-13 weeks (t ratio = 2.08, P = 0.025). At 14-42 weeks, only 19% of vessels stained for HSPG (41.3 +/- 5.8 vessels/mm2; t ratio = 2.04, P = 0.009).     

Loss of types XV and XIX collagen precedes basement membrane invasion in ductal carcinoma of the female breast

Ductal and lobular carcinomas comprise most malignancies of the female breast and the morbidity and mortality associated with breast cancer. During the progression from in situ to invasive stages, tumour cells penetrate the epithelial and vascular basement membranes (BM) to realize full metastatic potential. While the definition of these structures has primarily resulted from analysis of laminin and type IV collagen, characterization of newly discovered BM/BM zone (BMZ) proteins will further elucidate the interactions between tumour cells and the host stroma. We have studied the expression of two non-fibrillar BMZ collagens, the type XV proteoglycan and collagen XIX, in breast cancer where a linear, well-formed BM becomes fragmented and even lost in the progression of epithelial malignancy. In the normal breast, types XV and XIX were found in all BMZ: epithelial, muscle, neural, endothelial, and fat. In in situ lesions, these two collagens, and particularly type XV, were often absent from the BM/BMZ displaying a continuous or just focally disrupted type IV/laminin staining pattern. In contrast, infiltrating ductal carcinomas showed only rare traces of laminin and collagen IV reactivity adjacent to the glands and tumour nests, and similarly there was little if any evidence of types XV and XIX collagen. All four molecules were, however, detected in the interstitium associated with some of the invasive carcinomas. The data suggest that types XV and XIX collagen are lost early in the development of invasive tumours, prior to penetration and eventual dissolution of the epithelial BM. Disappearance of these proteins from the BM/BMZ may signal remodelling of the extracellular matrix to promote tumour cell infiltration.     

Pericellular deposition of basement membrane material in myxoid meningioma: Immunohistochemical evidence for unbalanced production of type IV collagen and laminin

Myxold meningioma seen In a 25-year-old man is presented. Hlstologlcally, Leu 7-positive meningotheliomatous tumor cells were embedded in the alclanophilic myxoid matrix. Characteristically, eosinophilic granular deposition was detected around the tumor cells and the boundary of tumor cells was not clearly defined. The pericellular deposits revealed the nature of the basement membrane with positive reactions by periodic acid-Schlff (PAS) sequence and immunostaining for type IV collagen, which is the major structural component of basement membrane. However, laminin, which is a non-collagenous glycoprotein of the basement membrane, was undetectable, and silver was not impregnated. Similar abnormal deposition of PAS-positive basement membrane-like material was observed in the myxoid stroma of a microcystic meningioma among 72 meninglomas additionally examined. The significance of the discrepant localization of immunoreactive type IV collagen and laminin is discussed.     

Immunocytochemical detection of basement membrane antigens in the histopathological evaluation of laryngeal dysplasia and neoplasia

Immunocytochemical detection of intrinsic components of the basement membrane (type IV collagen and laminin) was performed in biopsies of carcinoma in situ, dysplasia and hyperplasia of the laryngeal mucosa. We found a distinct and continuous basement membrane, containing both laminin and type IV collagen, at the border between epithelial cells and mesenchymal stroma in normal as well as in hyperplastic and dysplastic mucosa. In contrast, irregular discontinuities were found in some cases of carcinoma in situ and in invasive carcinoma. In addition, immunoreactivity for intracytoplasmic basement membrane components was noticed occasionally in neoplastic epithelial cells. In areas of inflammation, infiltration of leucocytes into the epithelium was occasionally accompanied by sharply defined small interruptions of the basement membrane. Our results indicate that immunohistochemical detection of basement membrane components can be of value for the demonstration of microinvasive growth in laryngeal cancer.     

Crush preparation findings of "sarcomatoid" chordoma of the sacrum: report of a case with histologic, immunohistochemical, and ultrastructural correlation.

We report on the crush preparation findings of a case of "sarcomatoid" chordoma occurring in the sacral region of a 78-yr-old Chinese male. The smears showed clumps and small cords of polygonal tumor cells containing bubbly cytoplasm and round to oval nuclei. Focally, there were also aggregates of long filamentous spindle cells and stellate bizarre cells with marked nuclear pleomorphism. Occasional tumor cells were seen in association with dense amorphous material. Histologic examination of the excised specimen showed features of the so-called "sarcomatoid" chordoma which consisted of prominent foci of mitotically inactive spindle and pleomorphic cells, in addition to the conventional chordoma areas. An osteosarcoma-like pattern of probably metaplastic nature was also seen within the tumor. Immunohistochemical study showed that most tumor cells expressed cytokeratins. Ultrastructural examination revealed the characteristic rough endoplasmic reticulum-mitochondria complexes. While there are many spindle and pleomorphic cells seen in crush preparations, the distinction from other true high-grade malignancies is important. Recognition of these "pseudoanaplastic" cytologic features also helps to expand the morphologic spectrum of chordoma.     

Methylthioadenosine phosphorylase and activated insulin‐like growth factor‐1 receptor/insulin receptor: potential therapeutic targets in chordoma

Currently there is no effective chemotherapy for chordoma. Recent studies report co‐expression of insulin‐like growth factor‐1 receptor (IGF1R) and its cognate ligand in chordoma, but it is unknown whether this receptor tyrosine kinase is activated in these tumours. Additionally, genetic studies have confirmed frequent deletions of chromosome 9p in chordomas, which encompasses the cyclin‐dependent kinase inhibitor 2A (CDKN2A) locus. Another gene in this region, methylthioadenosine phosphorylase (MTAP), is an essential enzyme of the purine salvage pathway and has therapeutic relevance because MTAP‐deficient cells are particularly sensitive to inhibitors of de novo purine synthesis. We investigated whether these pathways might be potential therapeutic targets for chordoma. Paraffin‐embedded tissue samples from 30 chordomas were analysed by immunohistochemistry for expression of the phosphorylated isoforms of IGF1R or the insulin receptor (pIGF1R/pIR) and selected downstream signalling molecules, including BCL2‐associated agonist of cell death protein (BAD). Expression of CDKN2A and MTAP proteins was also assessed. Skeletal chondrosarcomas, benign notochordal cell tumours, and fetal notochord were studied for comparison. Phosphorylated IGF1R/IR was detected in 41% of chordomas, together with activated downstream signalling molecules, and pIGF1R/pIR was absent in benign notochordal cell tumours and fetal notochord. Thirty‐nine per cent of chordomas were negative for MTAP immunoreactivity. Patients with pIGF1R/pIR‐positive tumours showed significantly decreased median disease‐free survival in multivariate survival analysis (p = 0.036), whereas phosphorylation of BAD at serine‐99 was found to be associated with a favourable prognosis (p = 0.002). Approximately 40% of chordomas demonstrate evidence of activation of the IGF1R/IR signalling pathway or loss of a key enzyme in the purine salvage pathway. Aberrant signalling cascades and disrupted metabolic pathways such as these may represent opportunities for novel targeted therapeutic approaches for the treatment of chordoma. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

An ultrastructural and immunohistochemical study of microcystic meningioma with emphasis on matrix proteins and connexin 26 type gap junctions

Although the histopathological subtypes of meningioma do not themselves appear to have prognostic significance, they are collectively important for defining the overall histopathological entity of microcystic meningioma (MCM) and allowing a distinction from other intracranial tumors, such as capillary hemangioblastoma, glioma, and metastatic renal cell carcinoma showing similar histology. Four cases of MCM were analyzed by conventional histology, immunohistochemistry, and electron microscopy. The present series of MCM was characterized by spindle- or cobweb-shaped tumor cells, characteristically associated small blood vessels, and a peculiar microcystic pattern. Among the microcystic meningeal tumor tissue, small areas of conventional subtypes were identified. Immunohistochemically, tumor cells showed the mesenchymal features of vimentin positivity and a rich distribution of matrix proteins around tumor cells. They lacked epithelial marker positivity but were faintly EMA positive. Ultrastructurally, primitive cellular junctions, desmosomes, and gap junctions were frequently seen between tumor cells. The gap junctions correlated with connexin 26 immunoreactivity. Although lacking an obvious epithelial nature, these features could be interpreted as showing an abortive differentiation mimicking meningothelial (arachnoidal) cells, which, physiologically, regulate cerebrospinal fluid between blood vessels and brain parenchyma.