Immunohistochemical detection of laminin in 98 human breast carcinomas: a light and electron microscopic study

The Basement Membranes in Sarcomatoid Carcinomas. An Immunohistochemical Study

Aims

Eight sarcomatoid carcinomas from various anatomical locations were investigated by immunohistochemical staining to laminin, type IV collagen and heparan sulfate proteoglycan, to study the characteristics of basement membranes at the interface between carcinomatous and sarcomatous tissues.

Methods

Paraffin wax embedded tissue sections from representative tumor samples have been stained with specific antibodies, using the peroxidase-antiperoxidase technique.

Results

In all cases several interruptions or discontinuities of the basement membrane staining pattern were seen. In 4 cases, larger defects or complete loss of staining was also noted. At these places, the boundaries between carcinomatous and sarcomatous tissue were often blurred.

Conclusions

Disruption and loss of basement membranes at interface between carcinomatous and sarcomatous tissues is a frequent finding in sarcomatoid carcinomas. These changes could be consistent with an epithelial origin of the sarcomatous component in these tumors by means of an epithelial-mesenchymal conversion mechanism.

In vitro regulation of hepatocellular carcinoma cell viability, apoptosis, invasion, and AEG-1 expression by LY294002

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, and is characterized by advanced clinical stages at diagnosis and very poor prognosis.

SUBJECTS AND METHODS

This study investigated the effects of PI3K inhibitor, LY294002, on suppression of astrocyte elevated gene-1 (AEG-1) and regulation of HCC cell viability, apoptosis, and invasion in vitro. Cell lines derived from normal liver and HCC were treated with LY294002 and evaluated by RT-PCR, western blot, cell viability, migration, and invasion assays.

RESULTS

The data showed that AEG-1 mRNA and protein were overexpressed in HCC cells, compared to the normal liver cells. LY294002 treatment of HCC cells significantly reduced tumor cell viability, but promoted apoptosis. Tumor cell migration and invasion assays showed that LY294002 treatment also decreased the capacity of HCC cell migration and invasion. Molecularly, LY294002 treatment down-regulated AEG-1 expression, AKT and GSK3β phosphorylation, and expression of cyclinD1, CDK4, VEGF and Bcl2, but up-regulated Bax and c-Myc expression.

CONCLUSION

The data from this study demonstrated usefulness of LY294002 for effective control of HCC. Future studies should investigate the effects of LY294002 on HCC cells in vivo before initiating clinical trials in HCC patients.

Loss of myoepithelium is variable in solid papillary carcinoma of the breast

AIMS

Reports on the frequency of myoepithelial loss in solid papillary carcinoma (SPC) of the breast, an unusual variant of papillary carcinoma with a solid pattern of expansile growth, have been strikingly contradictory. The aim was to clarify the frequency of myoepithelial loss in cases of SPC diagnosed at our institution.

METHODS AND RESULTS

Eleven cases of SPC with available blocks or unstained slides were retrieved from the M. D. Anderson archives or obtained from outside contributors. Immunohistochemistry for smooth muscle actin (SMA) and p63 was evaluated on the circumscribed nests that appeared to be non-invasive by haematoxylin and eosin morphology. Three of the 11 cases (27%) were positive for both SMA and p63 at the periphery of all such foci, whereas eight cases (73%) lacked staining for both myoepithelial markers in at least one focus. Of these eight cases, one was diagnosed with only microinvasion, yet metastatic tumour resembling the circumscribed primary SPC was identified in two ipsilateral axillary lymph nodes.

CONCLUSIONS

SPC of the breast frequently lacks myoepithelial markers at the tumour-stromal interface in spite of a circumscribed non-invasive appearance. Metastases from such tumours are infrequent, but can occur in cases that lack myoepithelial marker expression by immunohistochemistry.

Current Practical Applications of Diagnostic Immunohistochemistry in Breast Pathology

In recent years, immunohistochemistry has assumed an increasingly prominent role in diagnostic breast pathology. Immunohistochemistry is now frequently used in the evaluation of many epithelial proliferations of the breast. Common applications include the use of myoepithelial markers to evaluate for stromal invasion, E-cadherin to distinguish between ductal and lobular neoplasia, high molecular weight cytokeratins to differentiate usual ductal hyperplasia from ductal carcinoma in situ, immunohistochemical profiles to characterize site of origin of metastatic carcinomas, and cytokeratin stains to detect metastases in sentinel lymph nodes. Recent advances, practical considerations, and potential pitfalls in the use of immunohistochemistry in these five diagnostic categories are discussed herein.

Biotherapeutic approaches to pancreatic cancer

The incidence of adenocarcinoma of the pancreas has risen steadily over the past four decades. Since pancreatic cancer is usually diagnosed at an advanced stage and because of the lack of effective therapies, the prognosis of such patients is extremely poor. Despite advances in our understanding of the molecular biology of pancreatic cancer, the systemic treatment of this disease remains unsatisfactory. Conventional chemotherapy has not produced dramatic improvements in response rates or patient survival. New treatment strategies are clearly needed. This paper will review emerging therapies for pancreatic carcinoma. A deeper understanding of the molecular biology of cell growth and proliferation, as well as of neoplastic cell transformation, has led to advances in several areas, including the use of hormones and antihormones as adjuvant therapy; inhibition of tumour growth and metastasis by inhibitors of matrix metalloproteases and angiogenesis, and by small molecules, such as retinoids, which interfere with progression through the cell cycle; immunotherapy with monoclonal antibodies; disruption of intracellular signal transduction with farnesyltransferase inhibitors; and, finally, gene therapy with specifically designed vaccines.

Prostatic stem cells

Multipotent cells within the epithelial compartment, together with phenotypically 'plastic' mesenchyma cells (stromal stem cells), provide a repository of protected genetic information from which the structure, stability and functionality of the prostate gland can be maintained. However, mere preservation of cells in a non-dividing state is insufficient to provide the necessary reservoir of information from which the structure and function of the prostate gland can be retained or recreated. Rather, there is a constant dynamic interaction, at the level of information exchange, between stem cells (whether epithelial or mesenchymal) and their surrounding environment (both humoral and physical). Thus, with respect to epithelial stem cells, these reside within environmental 'niches' which allow their controlled and limited proliferation while preserving genomic integrity. Similar 'mesenchymal niches' are also predicted to occur, although not yet identified, thus providing the multipotent source from which the full spectrum of stromal phenotypes might be regenerated. Recent data from studies of the haematopoietic and hepato-biliary systems indicate that the potential scope of stem cells far exceeds the immediate phenotypic complement of those tissues within which they originate, being dependent upon their precise environment as well as their genomic integrity.

Pancreatic cancer: a review of emerging therapies

The incidence of adenocarcinoma of the pancreas has risen steadily over the past 4 decades. Since pancreatic cancer is diagnosed at an advanced stage, and because of the lack of effective therapies, the prognosis of such patients is extremely poor. Despite advances in our understanding of the molecular biology of pancreatic cancer, the systemic treatment of this disease remains unsatisfactory. Conventional chemotherapy has not produced dramatic improvements in response rates or patient survival. New treatment strategies are clearly needed. This paper reviews emerging therapies for pancreatic carcinoma. A more profound understanding of the molecular biology of cell growth and proliferation, as well as of neoplastic cell transformation, has led to advances in several areas, including the use of somatostatin analogues and antiandrogens as adjuvant therapy; inhibition of tumour growth and metastasis by inhibitors of matrix metalloproteinases and angiogenesis, and by small molecules such as retinoids, which interfere with progression through the cell cycle; immunotherapy with monoclonal antibodies; disruption of intracellular signal transduction with farnesyltransferase inhibitors; and finally gene therapy with specifically designed vaccines.

Effect of matrix metalloproteinase inhibition on pancreatic cancer invasion and metastasis: an additive strategy for cancer control

OBJECTIVE

To investigate the effect of a matrix metalloproteinase (MMP) inhibitor, BB-94, on the viability, invasion, and metastases of pancreatic cancer.

SUMMARY BACKGROUND DATA

Inhibitors of MMPs, enzymes that degrade extracellular matrix, have been tested as single chemotherapeutic agents for pancreatic cancer.

METHODS

Capan1 and AsPC1 cell lines were studied. BB-94 cytotoxicity was evaluated by cell proliferation assays. Production of MMP2 and MMP9 in conditioned media was demonstrated by gelatin zymography. The in vitro effect of BB-94 on cell invasion was assayed using invasion chambers. Hepatic metastases from pancreatic cancer were induced by intrasplenic injections of Capan1 or AsPC1 cells in nude mice. The in vivo effect of BB-94 on liver metastases was evaluated by comparing animals receiving BB-94 treatment with controls receiving vehicle alone. Variables measured included death rate and tumor burden (liver-to-body weight ratio).

RESULTS

BB-94 was not cytotoxic between 3 and 3,000 ng/mL. Zymography demonstrated production of MMP2 and MMP9 by both cell lines, with complete inhibition of these enzymes by BB-94 at 48 ng/mL. Invasion chamber assays showed that BB-94 (48-400 ng/mL) impeded cell invasion in vitro compared with untreated controls. In vivo, BB-94 prevented death or reduced the death rate from hepatic metastases in animals injected with Capan1 or AsPC1 cells. BB-94 treatment resulted in significant reductions in hepatic tumor burden compared with untreated controls.

CONCLUSIONS

Inhibition of MMP reduces both growth of pancreatic cancer metastases and the death rate. These actions do not reflect cytotoxicity but rather result from impaired cancer cell attachment, migration, and organ invasion. MMP inhibitors may provide an additive effect to cytotoxic agents in multidimensional treatment regimens for pancreatic cancer.

Areas of sinusoidal surface hepatocyte nuclear predominance in type C chronic hepatitis

AIMS/BACKGROUND

Thick hepatic plates have been considered one of the morphological characteristics of hepatocyte regeneration in cirrhotic nodules. They can be recognized by the sinusoidal surface predominance of their nuclei. We have investigated the prevalence of this in HBV and HCV infections.

METHODS AND RESULTS

This feature was more frequently present in type C chronic hepatitis with low activity of inflammation and low grade of fibrosis, than with type B chronic hepatitis. Additionally, this area of sinusoidal surface hepatocyte nuclear predominance (ASSHNP) was seen in zone II, rather than in periportal zones, in type C chronic hepatitis. Clinical data were analyzed statistically. Immunohistochemical reactivity of type IV collagen, laminin, Ulex europaeus agglutinin 1 lectin (UEA-1), and factor VIII-related antigen were increased in ASSHNP. Immunohistochemical staining of Ki-67 antigen was performed in order to assess the regenerative capacity of this area and showed a low level of regeneration. Ultrastructure of this area in type C chronic hepatitis showed a decrease in the number of mitochondria and an increase of nuclear pleomorphism together with basement membrane formation in the space of Disse.

CONCLUSION

Although the cause of these abnormalities was not clarified in this study, it is suggested that they are related to chronic hepatitis C virus (HCV) infection per se, rather than regeneration or inflammatory activity. These changes may be significant in HCV-associated hepatocarcinogenesis.

Histological and biological characteristics of microinvasion in mammary carcinomas < or = 2 cm in diameter

Fifty-two mammary carcinomas, 2 cm or less in diameter, were examined in order to clarify the morphology and biology of microinvasion. The morphological characteristics of microinvasion of carcinomas include: (i) a loss of myoepithelial cells and a rupture with concomitant loss of collagen IV and laminin in the basement membrane of involved mammary glands; and (ii) budding of carcinomas from the rupture into the stroma. When microinvasion was defined as a rupture of < 200 microm in the basement membrane with invasion, the number of microinvasions per 1 mm of basement membrane was larger in the tumors in which the area of invasion was larger. The prevalence of microinvasion showed a significant correlation with lymph node metastasis and the rate of histological deviation, while no correlation of expression of either estrogen receptors or progesterone receptors and c-erbB-2 protein was found. The study clarified that the early invasion of mammary carcinomas could be detected by the immunohistochemical method using anti-smooth muscle actin, laminin and collagen IV antibodies. The study also suggested that microinvasion might be an indicator of lymph node metastasis in mammary carcinomas < or = 2 cm diameter.

The matrix metalloproteinases and their inhibitors in pancreatic cancer. From molecular science to a clinical application

The matrix metalloproteinases (MMPs) and their tissue-specific inhibitors (TIMPs) are described and their roles in tumor invasion and metastasis are reviewed. The expression and activity of the MMPs and TIMPs in pancreatic cancer is reported and illustrated with immunohistochemistry and in situ hybridization. The role of MMP inhibitors (MMPIs) is reviewed in vivo and the use of novel MMPIs, e.g., BB94 (Batimastat) and BB2516 (Marimastat); in animal experiments are also described. Finally, the preliminary results from a phase 2 trial of BB2516 (Marimastat) in pancreatic cancer are reported.

Expression of collagenase (MMP2), stromelysin (MMP3) and tissue inhibitor of the metalloproteinases (TIMP1) in pancreatic and ampullary disease

It is now recognised that epithelial-stromal interactions are important in a wide range of disease processes including neoplasia and inflammation. Metalloproteinases are central to matrix degradation and remodelling, which are key events in tumour invasion and metastasis and may also be involved in tissue changes occurring in chronic inflammation. Immunohistochemistry was performed on sections from 50 patients with pancreatic cancer (n = 27), ampullary cancer (n = 12), low bile duct cancer (n = 3), neuroendocrine tumours (n = 3) and chronic pancreatitis (n = 5), using antibodies raised against collagenase (MMP2), stromelysin (MMP3) and tissue inhibitor of metalloproteinase (TIMP1) and developed using the avidin-biotin complex method. Abundance of MMP2, MMP3 and TIMP1 was greater in pancreatic and ampullary cancer than any other pathology and immunoreactivity in the malignant epithelial cells in pancreatic and ampullary cancer was greater than in the stromal tissues (in pancreatic cancer: MMP2 100% vs 37%, MMP3 93% vs 15%, TIMP1 93% vs 4%, P < 0.0001). There were strong correlations between the immunoreactivity of the two antibodies for MMP2 (P < 0.0001), between MMP2 and TIMP1 (P < 0.0001) and between MMP3 and TIMP1 (P < 0.0001). The immunoreactivity for TIMP1 in pancreatic and ampullary cancers with lymph node metastases was significantly less compared with those cases without lymph node metastases (P < 0.02) and there was an association between increased immunoreactivity for MMP2 and the degree of tumour differentiation (P < 0.01). The results implicate MMP2, MMP3 and TIMP1 in the invasive phenotype of pancreatic and ampullary cancer.

Immunocytochemical study of type IV collagen and laminin in canine mammary tumours

We performed an immunohistochemical study of the basement membrane (BM) proteins laminin and type IV collagen in 35 canine mammary tumours, histologically classified according to the World Health Organization's suggested classification. Laminin and type IV collagen were seen in extracellular locations but only laminin was present in epithelial and myoepithelial cells and chondrocytes. The BM was always continuous in adenomas and fibroadenomas. In the 20 malignant tumours studied, the basement membrane was continuous in one, discontinuous in five, and virtually absent in 14. When present, the BM of malignant tumours varied in width and distribution in the same area. The benign and malignant mixed tumours did not have BM separating epithelial and newly-formed mesenchymal structures. In areas of abundant myoepithelial cells in complex and mixed tumours, both benign and malignant, there were groups of BM fragments which differed in length and thickness and occasionally formed tangles. We have called these 'membranous thickets'. Our results indicate that myoepithelial cells are the main source of the BM proteins laminin and type IV collagen in canine mammary tumours.

Prognostic significance of autoantibodies to laminin in the sera of breast cancer patients: a preliminary report

Interactions between cancer cells and laminin play an important role in the metastatic cascade. The aim of this retrospective study was to evaluate the presence and the prognostic significance of autoantibodies to laminin in sera of patients with breast cancer. Our study population consisted of 71 high-risk primary breast cancer patients (median follow-up, 6 years). IgG, IgA and IgM were analysed at the time of surgery and before any treatment was given. Concentrations were measured by enzyme immunoassay with a highly purified antigen. IgG, IgA and IgM anti-laminin median values were, respectively 117%, 130% and 97% of normal absorbance. Higher concentrations of IgM to laminin were found in pre-menopausal patients as compared with post-menopausal patients (p < 0.001). Patients with high concentrations of IgG to laminin had lower disease-free (p = 0.003) and overall survival rates (p = 0.003). In breast cancer, assay of IgG to laminin could thus provide a cheap and easy prognostic index available for all patients.

Distribution of laminin, type IV collagen and fibronectin in the invasive component of breast carcinoma

Laminin, type IV collagen and fibronectin were examined immunohistochemically in the invasive component of breast carcinomas. Laminin was expressed around the invasive carcinoma cell nests in 38 (54%) of 71 cases. Immunoreactivity for type IV collagen was observed around the invasive carcinoma cell nests or the stroma apart from carcinoma cells in 44 (80%) of 55 cases. Fibronectin was strongly expressed in the stroma only in 75 (99%) of 76 cases. The expression of laminin significantly correlated with tubular formation in the invasive carcinoma cell nests and showed a tendency to be correlative to estrogen receptor (ER) and progesterone receptor (PgR) of carcinoma tissue, but no correlation among laminin expression, histological type, the age of patients, tumor size and lymph node metastasis was noted. Type IV collagen and fibronectin did not correlate to any clinicopathological factors such as histological type, grade of differentiation, the age of patients, tumor size, lymph node metastasis, ER and PgR status. No concordant expression of these extracellular matrices was seen.

Immunohistologic analysis of invasive phenotype in breast carcinoma. A clinicopathologic study

Acetone-fixed, cryostat sections of 81 snap-frozen invasive breast carcinomas were immunostained with monoclonal antibodies to Cathepsin D (CD), a protease believed to mediate extracellular matrix dissolution, and Type IV collagen, a constituent of basal lamina (BL). Most cases (48/81, 53%) exhibited focal, patchy BL distribution (1+) around tumor cell nests, although subsets with diffuse continuous (2+) peritumoral sheets (15/81, 19%) or near complete absence (0+, 23/81, 28%) were also observed. Elaboration of BL was correlated with favorable morphologic differentiation (0+ BL-57% poorly differentiated vs. 2+ BL-13% poorly differentiated, p = .01), absence of nodal or systemic metastases (0+ BL-78% metastatic vs. 2+ BL-40% metastatic, p = .02), and improved disease-free survival (0+ BL-63% recurred vs. 2+ BL-20% recurred, p = .05). In addition, neoplastic cells expressed CD more frequently in tumors which lacked detectable BL synthesis (0+ BL-91% CD+ vs. 2+ BL-57% CD+, p = .03). The observed relationships between morphologic growth pattern, BL synthesis and CD expression imply conventional grading in large parts reflects activity or extent of host tissue invasion by a given neoplasm. Widespread but heterogeneous distribution of BL in breast tumors also suggests partial equilibrium between neoplastic and host tissues in most cases.

Non palpable breast carcinomas. Histological and immunohistochemical studies of 160 cases

A series of 160 impalpable breast carcinomas was collected from 1979 to 1991. Mammographs showed microcalcifications (64%), or opaque images (36%). Surgical specimens were X-rayed during the intervention in order (i) to ascertain that the lesions detected on mammographs were removed, and (ii) to guide the pathologist in sampling tissue fragment for an appropriate microscopic evaluation of the lesions. During the intervention, the peroperation histological diagnosis was correct in 63% of the cases, whereas malignancies were underscored in 37%. No false positive diagnosis was recorded. A large majority (92%) of false diagnoses stated during surgery were in situ carcinomas diagnosed as epitheliosis and invasive carcinomas diagnosed as in situ carcinomas. In 63% of the cases the axillary lymph node could be removed during the first intervention. In 91% of the cases "in sano" margins of resection were evaluated as such during the intervention. The size of tumors ranged from 1 to 60 mm (m = 10 mm - SD = 8.45), 70% measuring less than 10 mm. Carcinomas were in situ (23.75%), microinvasive (13.75%) and invasive (62.5%). Carcinomas were ductal (78.1%), lobular (18.7%) and of other types (14.2%). A majority of intraductal carcinoma (68%) were comedocarcinomas. Invasive carcinomas accounted for grade I in 37% of the cases, grade II in 56%, grade III in 7%, ductal carcinomas and for tubular carcinomas in 15%. Immunodetection could be performed on frozen sections in 78 cases. Tumors were receptor positive in 58% of the cases. The greater growth fraction (Ki-67) and higher detection of HER-2/neu oncogene product were observed in comedocarcinomas. Diploid tumors accounted for 52% of those evaluated (n = 48).

Clinical significance of laminin deposition and T-cell infiltration in oral cancer

Biopsied specimens from 55 patients with squamous cell carcinoma (SCC) of the oral cavity were examined immunohistopathologically as to the clinical significance of basement membrane (BM) deposition and T-cell infiltration at the tumor-stromal border using monoclonal anti-laminin and anti-CD3 antibodies. According to the immunoreactivity, all specimens could be divided into three groups: group A, a continuous linear pattern of positive staining for BM around tumor nests; group B, an alteration of BM deposition around tumor nests with T cell infiltration into those tumor nests; and group C, an alteration of BM deposition around tumor nests without T cell infiltration into those tumor nests. These groups were correlated with clinical manifestations, such as tumor size, tumor regression rate with induction chemotherapy, and regional lymph node metastatic rate. In these groups, tumors classified as group C showed a trend toward resistance to chemotherapy and high metastatic characteristics. Tumors classified as group B, which showed the same alteration of BM deposition as a result of T cell infiltration into the tumor nests, showed a sufficient tumor regression rate with chemotherapy. The visualization of the staining for BM laminin and T cells in oral SCC appeared not only to increase our understanding of the biologic and clinical behavior of individual tumors, but could be a prognostic indicator.

Myoepithelial and basement membrane antigens in benign and malignant human breast tumors

Serial cryostat sections of 160 human breast lesions and of 9 lymph-node metastases were studied by indirect immunofluorescence. We used monoclonal antibodies (MAbs) to lining-epithelium-specific keratin 8 and to myoepithelium-specific keratin 17 in combination with polyclonal and monoclonal antibodies to major basement membrane components, laminin, collagen type IV, entactin/nidogen, and large heparan sulfate proteoglycan (perlecan) core protein. Continuous basement membranes adjacent to a basal layer of keratin-17-positive myoepithelial cells were typical for normal, benign and in situ carcinomatous structures. In invasive and metastatic structures, always formed by keratin-8-positive tumor cells, basement membranes were found only rarely and with conspicuous fragmentations. This lack of basement membranes correlated with loss of myoepithelium identified by staining for keratin 17. In comedo structures of invasive ductal carcinomas and in papillary carcinomas, fibrovascular complexes with numerous blood vessels and deposition of basement membrane material were often seen in the stroma. Immunomorphological analysis of 41 cases of doubtful diagnosis at intra-operative biopsy was also performed. A combination of MAbs to keratins 8 and 17, and to basement membrane components, made it possible to distinguish between morphologically similar benign and malignant proliferations and to detect single-cell invasion of the stroma. This combination of antibodies may be recommended as an auxiliary immunomorphological tool for differential diagnosis of intra-operative breast biopsies in dubious cases.

Distribution of basement membranes in primary and metastatic carcinomas of the prostate

The presence of periacinar and pericellular basement membranes (BMs) has been reported recently in common prostatic adenocarcinomas. In this study we extended our investigations of BMs on lymph node and hematogenous metastases, primary prostatic cancer with unusual histologic features, and posttreatment tumors. In contrast to prostatic malignancies that derive from the transitional epithelium (squamous cell carcinoma, prostatic transitional cell carcinoma) and prostatic involvement by bladder cancer, inconspicuous stromal changes and distinct BM formations at the site of tumor invasion were observed in carcinomas deriving from the secretory epithelium (papillary ductal carcinoma) and from the basal cell (basal cell carcinoma). Even highly malignant anaplastic and small cell carcinomas, as well as irradiated and/or hormonally treated tumors, showed distinct BM formations in contact with the stroma. The same observations could be made in lymphatic and hematogenous metastases of different anatomic sites. These findings indicate that prostatic malignancies may retain BMs even in high-grade lesions, metastases, posttreatment tumors, and variants of prostatic adenocarcinoma.

An immunohistochemical study of the breast using antibodies to basal and luminal keratins, alpha-smooth muscle actin, vimentin, collagen IV and laminin. Part I: Normal breast and benign proliferative lesions

The distribution of simple epithelial (K8/18/19) and basal (myoepithelial) (K5/14) keratins, alpha-smooth-muscle actin, vimentin, collagen IV and laminin in normal mammary glands and in benign proliferative lesions was studied using monoclonal antibodies (mAbs). These antibodies (Abs) identified myoepithelial cells and luminal cells specifically. In lesions with adenosis and papillomas, the two-layered formation resembled that of normal glands with a purely myoepithelial-epithelial differentiation. In scleradenotic lesions, the main cell was of myoepithelial immunophenotype with intermixed trabecular-tubular proliferations of simple-type epithelium. The sclerosis seems to be the result of an irregular basal lamina synthesis by the myoepithelial cells. In contrast to these lesions, epitheliosis represents a purely intraluminal cell proliferation of clearly simple epithelial immunophenotype and of cells with a basal keratin phenotype, lacking myoepithelial differentiation antigen actin. The basal keratin type epithelium may represent post-stem or intermediate cells developing into luminal epithelium. Epitheliosis appears to be a purely epithelial hyperplasia with striking similarity to the regeneration of normal breast epithelium. The different proliferative patterns may give an explanation for differences in potential cancer risks of patients with these lesions.

Pseudoangiosarcomatous carcinoma: a clinicopathological study of seven cases

Seven cases of carcinoma mimicking angiosarcoma occurring in skin (3 cases), breast (3) and lung (1) are described. The cutaneous, pulmonary and one of the breast carcinomas were poorly differentiated and squamous in type; the other two breast tumours were poorly differentiated ductal carcinomas with focal squamous differentiation. Histologically, the pseudoangiosarcomatous pattern was due to complex anastomosing channels and spaces lined by neoplastic cells. The spaces contained hyaluronic acid. The neoplastic cells exhibited cytokeratin positivity but yielded negative results with the endothelial cell markers, factor VIII-related antigen and CD 34 (QB-END/10). Two breast tumours showed binding of UEA-1. Ultrastructurally, unequivocal epithelial differentiation was demonstrated in six of the cases. Pathogenetically, these tumours appeared to be variants of acantholytic squamous cell carcinoma. Recognition of this unusual form of carcinoma is important, as an incorrect diagnosis of angiosarcoma may lead to inappropriate treatment and prognostication.

Laminin expression by two clones isolated from the colon carcinoma cell line LoVo that differ in metastatic potential and basement-membrane organization

In the present report we describe the characteristics of 2 clones, E2 and C5, isolated from the human colon adenocarcinoma cell line LoVo. When grafted to immunosuppressed newborn rats, these clones formed tumors that varied with regard to differentiation rate, basement-membrane organization and lung metastatic potential. Production and distribution of laminin by E2, C5 and related tumors was studied by immunohistochemistry with an anti-laminin monoclonal antibody 4C12 (MAb 4C12). In lowly metastatic E2-derived tumors, strong regular stainings were observed which were strictly peri-tumoral and corresponded to the basal lamina. Since the antibody interacted with human laminin (the graft) but not with rat laminin (the host), this result indicated that basement-membrane laminin was supplied mainly by tumor-cell synthesis. In highly metastatic C5-derived tumors, the staining obtained with MAb 4C12 was peri-cellular and unorganized. Laminin synthesis by E2 and C5 cells in sub-cultures or soon after dissociation from explanted tumors was studied by metabolic labelling with 35S-methionine under steady-state conditions followed by immunoprecipitation and SDS-PAGE. High-molecular-weight laminin comprised by disulfide-linked A and B chains, i.e., heterotrimeric laminin, was found in cell lysates and in the secretion medium of cell lines and tumor cells. In addition, B1B2 dimers and free B chains were observed in cell lysates. Quantitatively, laminin expression by E2 and C5 clones or tumor cells was not significantly different. These findings suggest that basement-membrane defects in invasive clone LoVo C5 were not due to laminin under-expression.

Distribution of individual components of basement membrane in human colon polyps and adenocarcinomas as revealed by monoclonal antibodies

Double-label immunofluorescence was used to monitor basement-membrane composition and integrity in 22 human colon polyps, 36 adenocarcinomas and 2 metastases. Cryostat sections were stained with polyclonal anti-laminin anti-serum combined with monoclonal antibodies (MAbs) to all major basement-membrane components (laminin, entactin/nidogen, collagen type IV and large heparan sulfate proteoglycan), as well as to keratin 8. In all adenocarcinomas, including mucinous, basement membranes were altered more at the invasive front than in the parenchyma. The degree of this alteration was inversely correlated with the level of tumor differentiation. An uncoordinated loss of basement membrane components (dissociation of markers), previously described by us in rat colon adenocarcinomas, was also found in human tumors. In the great majority of adenocarcinomas a pronounced stromal reaction was seen. It was manifested by the presence of fibrillar deposits of basement-membrane components, mainly of collagen type IV and/or heparan sulfate proteoglycan. This reaction was never observed in polyps and may be derived from myofibroblasts reported to accumulate in colon cancer stroma. The combined use of antibodies to basement-membrane components and to a specific keratin may constitute an adequate immunohistochemical test for the presence of invasion, and may be useful in the histologic analysis of polyps, especially in dubious cases.

Co-ordinate expression of the alpha-6 integrin laminin receptor sub-unit and laminin in breast cancer

Interactions between cells and extracellular matrices are mediated in part by a family of heterodimeric molecules known as integrins. We have investigated, using immunohistology, the distribution of six integrin alpha sub-units in normal breast tissue and 26 breast carcinomas. Alpha-1 integrin (collagen/laminin receptor sub-unit) was detected in myoepithelium, but not in luminal epithelium nor in most (20/26) carcinomas. Its expression on fibroblasts was enhanced in desmoplastic stroma. Both benign and malignant epithelium showed uniform positive staining for alpha-2 (collagen receptor sub-unit) and for alpha-3 (collagen/fibronectin/laminin receptor sub-unit). All epithelium was negative for alpha-4 (sub-unit of a fibronectin receptor). Epithelial staining for alpha-5 (fibronectin receptor sub-unit) was weak in all samples. Alpha-6 (sub-unit of two integrin laminin receptors) showed conspicuous changes in all invasive carcinomas. In normal tissues, there was weak staining of epithelial cytoplasm with alpha-6 antibody and moderate cell membrane staining. Strongest staining was present in a basement membrane distribution. In carcinomas, loss of cytoplasmic and cell membrane staining was variable, but basal membrane staining was diminished or absent in all tumours. Loss of basal membrane staining for alpha-6 integrin corresponded closely to loss of immunoreactivity for its ligand laminin in invasive breast cancer.

Basement membranes in fetal, adult normal, hyperplastic and neoplastic human prostate

The distribution of the various basement membrane (BM) components (type IV collagen, laminin and heparan sulphate proteoglycan) was studied in fetal, adult normal, hyperplastic and neoplastic prostates in formalin- and ethanol-fixed paraffin-embedded specimens. Stromal, epithelial and neoplastic BMs expressed differential susceptibility to pepsin treatment, suggesting conformational differences in the expression of epitopes on BM proteins in distinct anatomical structures and various lesions of the human prostate. In fetal prostate the acinar BM was regular and continuous in contrast to normal adult prostate and various hyperplastic conditions where the acinar BM was locally thickened or unreactive to the anti-BM antibodies. The localization pattern of BM components in grade I and grade II phases of prostatic cancer did not differ essentially from those found in various hyperplastic lesions. Regardless of the histopathological grade of malignancy, prostatic carcinoma cells were surrounded by distinct pericellular and periacinar membranes which were present even at points of contact with the stroma. This suggests that stroma invasion is invariably associated with neoplastic BM formations. Immunohistochemical evidence of the stromal or epithelial origin of neoplastic BMs could not be found. However, the consistent extracellular distribution of neoplastic BM components in contact with the stroma indicates that the elaboration of BM material requires a stromal influence.

Fel d I allergen distribution in cat fur and skin

Immunohistochemical procedures were performed to ascertain Fel d I antigen (Ag) distribution in cat fur and skin biopsy specimens and to analyze Fel d I allergen concentrations in fur. One hundred strands of fur and 24 skin biopsy specimens (6 by 4 by 3 mm) from shaved areas were collected from 11 different cats. Freshly depilated hairs were immunostained by free-floating monoclonal anti-Fel d I, avidin-biotin-peroxidase complex, and either processed for scanning electron microscopic examination or mounted on glass slides for computer-assisted densitometric analysis (SAMBA system). Skin biopsy specimens were promptly frozen and sectioned just before the immunohistochemical processing. Densitometric analysis of fur demonstrated that immunoprecipitate concentrations were tenfold higher at the root than at the tip. However, this finding may be explained by decrease of the thickness of the hair cortex that varied in similar proportions. The Ag accumulated on the strand surface but may focally penetrate into the medulla through the scale-like cortical interstices. In skin biopsy specimens, Fel d I Ag was found in epithelial squamous cells, within the epidermis and hair follicles, on the surface of the epidermis and hair follicles, and in sebaceous gland cells. These data suggest that Fel d I Ag is produced by sebaceous cells and, to a lesser extent, by basal squamous epithelial cells and that it is stored mainly on the surface of the epidermis and fur.

Two monoclonal antibodies identify antigens preferentially expressed on normal human breast cells versus breast cancer cells

In order to obtain antibodies with specificity toward normal mammary epithelial antigenic determinants, we immunized BALB/c mice with normal milk cells and screened the hybridomas against an undifferentiated breast cancer cell line H466B, peripheral blood lymphocytes and normal fibroblasts. Two hybridomas were generated, which produced BA6 (IgG1) and CA4 (IgM) monoclonal antibodies (MAbs). These MAbs did not react with 5 breast cancer cell lines. In cryostat sections of normal human breast tissue, BA6 was reactive with 6/6 and CA4 was reactive with 12/13 specimens both showing an apical staining of epithelial cells. Conversely staining of malignant cells in breast cancer biopsies was observed in 4/33 specimens with BA6 and in 4/19 specimens with CA4. Computerized image analysis (SAMBA) of immunostained sections showed homogeneous distribution of staining, with a high percentage of stained cell surfaces in normal breast (mean percentages of positive surfaces : BA6 : 75% and CA4 : 82%) while, in malignant samples, staining was heterogeneous, with a mean percentage of positive surface of 25% for BA6 and 12% for CA4. Both MAbs reacted strongly with human milk fat globule membranes (HMFGM) and skimmed milk. FPLC size exclusion chromatography of skimmed milk showed that CA4 and BA6 reactive materials eluted in distinct peaks in high molecular weight ranges. Electrophoretic separation of HMFGM followed by CA4 staining detected a high molecular weight reactive band (Mr 380-600 kDa). CA4 and BA6 reactivity was reduced by protease treatment of the antigen but was not affected by neuraminidase digestion, by methanol extraction or by Na-metaperiodate oxidation. After perchloric acid treatment of HMFGM, BA6 activity was lost while the CA4 activity was found in the soluble fraction. The results reported suggest that the two MAbs identify two distinct novel epitopes of normal breast cells.

Monoclonal antibodies for radioimmunoscintigraphy of breast cancer

Breast cancer is the leading cause of cancer deaths among females, and it is estimated that each year, one in ten American women will be newly diagnosed as having the disease. It is therefore not surprising, that a great deal of effort has been made to better understand the biology of breast cancer, and that investigators keep up the search for new tools to better characterize, diagnose and treat these tumours. In this regard, the introduction of the hybridoma technique in 1975 by Kohler and Milstein has lead to an extensive work in the characterization of monoclonal and polyclonal antibodies against breast cancers. A large number of antibodies has been raised to different epitopes present in normal and neoplastic breast tissue; but unfortunately we have yet to find a highly sensitive and specific monoclonal antibody for breast cancer that can successfully be used for scintigraphic detection of nodal metastases and for radioimmunotherapy treatment of this disease. As possible radioimmunodiagnostics, antibodies are known which react with the following antigens: (1) cytoskeletal proteins (2) breast cell products (3) steroid receptors (4) putative tumor-associated antigens (5) oncogene products (6) pregnancy-related products (7) basement membrane antigens (8) degradative enzymes (9) cell receptors for extracellular matrix molecules (10) multidrug resistance gene product (p-glycoprotein) (11) proliferative markers.

Immunohistochemical study of jaw cysts: different existence of keratins in odontogenic and non-odontogenic epithelial linings

Keratins and secretory component (SC) were immunohistochemically examined in fresh tissue samples from 45 odontogenic and 35 non-odontogenic cysts. Lining epithelia of almost all cases contained keratins which reacted with polyclonal antibodies (Dako, Bio-Science), and no difference could be found between the two groups of lesions. By staining with two monoclonal antibodies against keratins, i.e., RGE53 (Bio-Science) and RKSE60 (Bio-Science), it was revealed that the epithelia of non-odontogenic cysts, which were columnar epithelium in most cases, had fully and positively reacted with RGE53, while none of the cases was positive for RKSE60. In contrast, the squamous linings of odontogenic cysts except for two cases did not react with RGE53, and few cases possessed RKSE60-reactive keratin. SC was also contradictory. All non-odontogenic cysts exhibited SC. Regarding each pair of non-odontogenic and odontogenic cysts covered with RGE53 and SC-positive, and RKSE60-negative squamous epithelium, it seemed reasonable from the staining results to conclude that the squamous linings were metaplastic from the columnar epithelium. Based on the results, concomitant examinations of SC with keratins will be helpful in deciding the epithelial derivation of jaw cysts.

Distribution of laminin in the murine pituitary

The distribution and cellular localization of the glycoprotein laminin were investigated by light and electron microscopic immunocytochemistry in the adult murine pituitary gland. Immunoblots confirmed that laminin was the only protein in the pituitary gland of the adult male mouse to react with antilaminin serum. Laminin immunoreactivity was demonstrated at the light microscopic level simultaneously with that of beta-follicle stimulating hormone (beta-FSH) and beta-luteinizing hormone (beta-LH). In addition to its distribution is basal laminae, laminin immunoreactivity was coincidently expressed in gonadotrophs with the immunoreactivities of beta-FSH and beta-LH. Electron microscopic immunocytochemistry was employed on aldehyde-fixed sections embedded in L.R. White. Sites of binding of primary antisera to laminin were identified with affinity-purified secondary antisera directly coupled to 20 nm particles of colloidal gold. Three antisera recognizing laminin were compared and found to result in an identical pattern of immunoreactivity. Laminin was found extracellularly only in formed basal laminae in all three lobes of the pituitary and was not found in extracellular matrices of connective tissue. Laminin immunoreactivity was also found intracellularly in gonadotrophs but in none of the other endocrine or non-endocrine cells of the anterior lobe. Within gonadotrophs, only secretory granules were labeled. The majority, but not all, secretory granules were labeled in each of the gonadotrophs examined, and the proportion of granules labeled with laminin could not be increased by doubling the concentration of anti-laminin serum. Laminin immunoreactivity segregated with the subset of secretory granules containing beta-FSH. In contrast, laminin immunoreactivity was absent in the smaller subset of secretory granules that contain serotonin.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation between laminin and type IV collagen distribution in breast carcinomas, and estrogen receptors expression, lymph node and vascular involvement

The laminin (Lam) and type IV collagen (Coll IV) and estrogen receptor (ER) immunodetections were assessed in a large series of 400 human breast carcinomas. In all the cases the patient's age, the tumor size, the histological type and grade, the presence or the absence of axillary lymph node metastasis and of vascular invasion in tumor borders, and ER tumor content were recorded. Monoclonal anti-Lam, anti-Coll IV were applied with the avidin-biotin-peroxidase complex and monoclonal anti ER with peroxidase anti-peroxidase complex, on frozen sections. A computerized system of image analysis referred to as SAMBA (TITN) with specific software for tissue sections analysis permitted a multiparametric quantitative analysis of immunostained surfaces. With this system, in each tumor, the cellularity, the percentage of Lam, Coll IV and receptor positive surfaces versus the total cell surface and versus the epithelial (keratin positive) surface, the integrated optical density IOD histograms were obtained and correlated to morphometrical and standard histological data. From this study, it was shown that: (1) Lam and Coll IV immunostained epithelial basement membranes in carcinomas were correlated to the presence of estrogen and progesterone receptor antigenic sites within the tumors, with a significant decrease of the positive staining in ER-ICA negative tumors in comparison to ER-ICA/PR-ICA positive tumors. (2) The combined densitometric and morphometric evaluation demonstrated a decrease of Lam and Coll IV immunostaining in malignant tumors, correlated to (i) the presence of peritumorous vascular invasion and (ii) keratin positive cells in bone marrow (iii) axillary lymph node involvement. It is concluded that the variations in Lam and Coll IV antigens distribution may be relevant indicators of tumor metastatic potential in breast carcinomas and that computerized image analysis enables the standardization of the evaluation antigens distribution.

Stromal changes in early invasive breast carcinoma. An immunohistochemical, histoenzymological and ultrastructural study

The purpose of this work was to detect in periductal connective tissue of breast carcinoma in situ changes induced by intraductal tumor cells before any dehiscence in basement membrane. Histological, electron microscopic, immunohistochemical and histoenzymological methods were used in 3 carcinomas in situ, 4 microinvasive carcinomas and 13 control invasive carcinomas. We could demonstrate a high functional activity of fibroblasts with secretion of mucopolysaccharides and type III collagen around intraductal carcinomas. These changes occurred simultaneously to those of the basement membrane which was either thinning or thickening. Any dehiscence in basement membrane secondarily induced in this periductal stroma the usual changes seen in invasive stroma, peculiarly numerous vascular pedicles, myofibroblasts, elastic material. These periductal stromal changes are interpreted according to recent concepts about the possible influence of tumor cells upon their environment: stimulation of mitotic and metabolic activity of fibroblasts: stimulation of angiogenesis by means of an angiogenic factor.

Gonadectomy induces laminin biosynthesis and basement membrane assembly in anterior pituitary glands of adult rats

Laminin biosynthesis and basement membrane assembly in anterior pituitary glands of gonadectomized rats were studied by immuno-electron microscopy and radioimmunoassay. Three weeks after gonadectomy, rats received intravenous injections of sheep anti-laminin IgG conjugated to horseradish peroxidase, and glands were fixed and processed for microscopy 1 h later. Peroxidase reaction product uniformly labeled all perivascular and glandular epithelial basement membranes. In addition, reaction product was also found in abnormally multi-layered basement membranes seen especially beneath gonadotrophs, and unusual basement membrane-like structures projecting between gonadotrophs were also labeled. Pituitary sections from gonadectomized rats labeled with pre-embedding immunoperoxidase and post-embedding immunogold techniques also localized intracellular laminin within biosynthetic organelles and "light body" vesicles of gonadotrophs. Neither abnormal basement membrane structures nor intracellular laminin were detected in pituitaries of nongonadectomized, control rats. Radioimmunoassays of pituitary homogenates showed nearly twice as much soluble laminin (approximately 15 ng/gland) in gonadectomized rats than in controls (approximately 8 ng/gland), which paralleled gland growth, but serum laminin concentrations did not differ (approximately 10 ng/ml in both groups). When anterior pituitary glands of gonadectomized rats that received injections of anti-laminin IgG-HRP were fixed 5 days after injection, lengths of unlabeled basement membrane were distributed between labeled lengths. This indicated that new basement membrane was "spliced" into old by a process similar to that seen in normal development. Supplementation of gonadectomized rats with testosterone, however, arrested laminin biosynthesis and basement membrane assembly and reversed glandular hypertrophy. These results indicate that, in an absence of sex hormone feedback, renewed synthesis of basement membrane components occurs in the anterior pituitary and is probably necessary to support the additional growth and differentiation of gonadotrophs and other pituitary cells.

Destruction of basement membrane and cell infiltrates in oral lichen planus

Immunohistochemical staining analysis of oral lichen planus (OLP) using monoclonal antibodies (MoAbs) against the components of basement membrane (BM) and infiltrated cells was performed in 27 cases. Integrity of lining epithelial BM was more strictly elucidated by staining for laminin and type IV collagen than by fibronectin. Staining patterns of laminin were similar to type IV collagen. In the cases examined, continuity of BM was proven by laminin staining in 10 cases, partially destructive BM was seen in 9 cases and complete destruction of BM in 8 cases. Dividing OLP into 20 symptomatic (ulcerative/erosive) and 7 asymptomatic (non-ulcerative/-erosive) cases, intact BM could be observed in only 5 cases of the symptomatic group, while 5 cases of the other group possessed undamaged BM. The difference between the two groups was significant. Stromal and epidermal cell infiltrates, which were mainly composed of T cell subsets with accompanying Leu-M5 and 6-positive cells, were correlated with the condition of BM. Stromal Leu-M5+ and Leu-6+ cell infiltrates were clearly more dominant in laminin-negative (BM-destructed) cases than infiltrates in BM-intact cases. This relation was also found in epidermal infiltrates with the same manner of Leu-4 infiltration. From the above, it seems that the integrity of BM is concerned with cell infiltrates and clinical manifestations of OLP.

Laminin-mediated adhesion in metastatic rat rhabdomyosarcoma cell lines involves prominent interactions with the laminin E8 fragment

In vitro attachment assays were carried out to assess adhesion between two basement membrane proteins, type IV collagen and laminin, and rat rhabdomyosarcoma (RMS) cell lines with different metastatic potentials. Whereas cells did not adhere to type IV collagen, adhesion to laminin appeared to be very sensitive as maximal adhesion was achieved in dose-response assays with only nanograms of laminin. Adhesion was mediated by interactions between coated laminin and cell surface components, probably receptors, but not endogenous laminin. Laminin-mediated adhesion of RMS cell lines was compared with that of the MCF-7 (human mammary carcinoma) and the L6 (rat myoblast) cell lines. In dose-response assays, RMS cell lines required 10 times less laminin to reach half-maximal attachment rates than MCF-7 and L6 cell lines. Two laminin fragments, P1 and E8, which are structurally and immunologically distinct as shown by alpha-helix content, SDS-PAGE and monoclonal antibody mapping, supported adhesion by RMS cells and L6 myoblasts, but MCF-7 adhered only to P1. This fragment was 10 times less active than laminin in RMS cell lines. Attachment in dose-response assays and adhesion inhibition studies by antibodies revealed that E8 accounted for the activity of laminin in RMS cell adhesion. Adhesion in the RMS cell lines was dominated by interaction with E8 regardless of metastatic potential.

Immunocytochemical assays in human endometrial carcinomas: a multiparametric computerized analysis and comparison with nonmalignant changes

Immunocytochemical assay (ICAs) were performed on frozen sections from human endometrial samples (n = 89) including normal endometrium, decidua, hyperplasia with and without atypia, and carcinomas. Monoclonal antiestrogen receptor (ER), anti-laminin (Lam), anti-type IV collagen (Coll IV), and anti-Ki67 were applied with avidin-biotin-peroxidase complex or peroxidase-antiperoxidase complex. The results of the ICAs were evaluated through a computerized system of image analysis referred to as SAMBA. It was shown that this system provided for an accurate reliable and reproducible analysis of ICAs in tissue sections. It is concluded that this multiparametric and standardized method of analysis of ICAs can further be applied in correlations with clinical and biochemical data.

Immunodetection in fine-needle aspirates and multiparametric (SAMBA) image analysis. Receptors (monoclonal antiestrogen and antiprogesterone) and growth fraction (monoclonal Ki67) evaluation in breast carcinomas

Immunocytochemical assays (ICA) using monoclonal antiestrogen receptors (ER ICA), antiprogesterone receptors (PR ICA), and monoclonal antibody Ki67 (Ki67 ICA) were performed in 127 breast carcinomas. The immunostaining procedures were applied on frozen tissue sections, tumour imprints, and fine-needle aspirates in order to compare the variations in the distribution of the antigens detected in the three different types of preparations. Positive reactions detected with peroxidase-antiperoxidase and avidinbiotin-peroxidase, and alkaline phosphatase-antialkaline phosphatase complexes were evaluated through a computerized system of image analysis referred to as SAMBA 200 (SAMBA TITN, Grenoble, France). Application programs specifically developed for the analysis of tissue sections and of cytologic preparations were applied. This system allowed a multiparametric, accurate, reliable, reproducible and automatized evaluation of the heterogeneity of the antigenic sites in tumors. For each markers positive cell surface (PS), and integrated and mean optical densities (IOD, MOD) and IOD histograms were compared. It was shown that (1) there was no significant variation in optical densities in cell imprints and aspirates whereas PS significantly (P less than 0.01) differed in both preparations; (2) there were significant differences of the optical densities between tissue sections and cytological preparations, either imprints or aspirates, likely due to randomly cut nuclei in tissue sections; and (3) there was a significant difference between the PS of tissue sections and aspirates but no significant difference between tissue sections and imprints. It is concluded that fine-needle aspiration constitutes a convenient method for cell sampling, reliable for the diagnosis of malignancies. However, it may not reflect the heterogeneity of cell subpopulations in tissue.

Paucity of fibronectin in invasive lobular carcinoma of breast

Fifty-four cases of invasive carcinoma of breast were immunostained for fibronectin and laminin. They included 36 cases of invasive ductal carcinoma and 18 cases of invasive lobular carcinoma. Although there was some heterogeneity within tumours, it was found that whilst the majority of ductal carcinomas (31/36) had abundant fibronectin at cell/stroma boundaries or diffusely throughout stroma, a substantial proportion of lobular carcinomas (12/18) had very little (P less than 0.001). This difference could not be related to differences in laminin immunoreactivity, which was most commonly scanty or absent in both tumour types. It is postulated that the characteristic infiltration pattern of lobular carcinoma may be attributed in part to paucity of stromal fibronectin.

Distribution of basement membrane components in human hepatocellular carcinoma

The distribution of fibronectin (FN), laminin (LAM), and collagen IV (Coll IV), three components of the basement membranes (BM), was investigated in human hepatocellular carcinoma (HCC) and the surrounding uninvolved liver and was compared with the grade of differentiation of the tumor. The following three patterns of BM antigens were observed in HCC: (1) peritrabecular or periacinar, (2) pericellular, and (3) stromal-vascular. In the more differentiated tumors, FN, LAM, and Coll IV were observed in a peritrabecular or periacinar pattern whereas a pericellular pattern was only seen with anti-FN antisera that occasionally stained the content of acini. Double staining showed that the four antigens were usually codistributed. Occasionally, however, there was a different distribution along the BM suggesting an heterogeneity in the composition of BM. In the more anaplastic tumors and in the intrahepatic metastasis, BM components were seen around vessels and in the stroma and they were usually fragmented. The finding that FN can be located pericellularly or within acini supports the concept that FN is synthesized, at least in part, by hepatoma cells. The peritrabecular and periacinar location of Coll IV and LAM suggests a sinusoidal cell derivation of these two antigens. The immunohistochemical staining patterns for BM in HCC reflect the differentiation of the tumor, with differentiated tumors showing a relatively intact BM and poorly differentiated tumors showing a sharply defective BM.

Immunohistochemical localization of laminin in the basement membranes of normal, hyperplastic, and neoplastic human prostate

We examined the effects of fixatives and antibody sources on the immunohistologic localization of laminin in normal and cancer-containing human prostates and studied the localization patterns in carcinomas of varying degrees of histologic differentiation. Two different polyclonal antibodies were localized in paraffin-embedded or cryostat sections of fixed (alcohol, formalin, and paraformaldehyde) or unfixed tissue, using the immunofluorescence (IF) or immunoperoxidase (IP) techniques, with positive and negative controls. We found that the IF reactions were more intense in unfixed or alcohol-fixed sections than in paraformaldehyde-fixed specimens. IP reactions were very weak or absent in fixed and paraffin-embedded sections, but pepsin treatment of these sections resulted in more intense and uniform IP reaction products, stronger than in unfixed or ethanol-fixed cryostat sections. With the IP technique, laminin localization was intense and uniform in the basement membranes (BM) of acini, blood vessels, smooth muscle, and nerve fibers in normal prostate, benign hyperplasia (BPH), and well-differentiated carcinomas. The BM of poorly differentiated carcinomas showed widespread absence of laminin reactivity. In normal BPH and well-differentiated tumors, occasional epithelial cells and their surface and acinar lumina had laminin reactivity. However, in higher grade tumors, numerous neoplastic cells had laminin reactivity in cytoplasm, their surface, and secretory material. Some macrophages and neutrophils also contained laminin reactivity, presumably of degraded laminin. In some moderately and poorly differentiated tumors, the BM of small capillaries did not contain laminin. The BM of larger vessels always had laminin reactivity, even in the higher grade tumors.

Type IV collagen immunostaining and computerized image analysis (SAMBA) in breast and endometrial disorders

Type IV collagen immunostaining was performed on tissue sections from a large series of non-malignant and malignant disorders of the breast and endometrium. The results were analysed by means of a computerized system of image analysis referred to as SAMBA. It was shown that this system provided an accurate, reliable, reproducible, automated and multiparameteric analysis of collagen IV immunoprecipitates. It was concluded that this standardized method of analyses can be routinely used for the measurement of collagen IV, thus enabling correlations to be sought with histopathological and clinical data.