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)

Laminin and type VII collagen distribution in different types of human lung carcinoma: correlation with expression of keratins 14, 16, 17 and 18.

The expression patterns of basement membrane components and keratin intermediate filament proteins were studied in normal human bronchial epithelium and 56 lung carcinomas using monoclonal antibodies to laminin, type VII collagen and the individual keratins 14, 16, 17 and 18. In normal lung, laminin and type VII collagen were present between the epithelium and the lamina propria of bronchi and bronchioles. Keratin 14 was expressed in the basal cells, keratin 17 in the basal and some suprabasal cells and keratin 18 in the columnar cells of the bronchi and bronchioles. Keratin 16 was not present in normal bronchial epithelium. Laminin was found in all subtypes of lung carcinoma, but type VII collagen was present only in squamous cell carcinomas, where it showed a reduction in expression with decreasing differentiation. Type VII collagen was not identified in adenocarcinomas, small cell carcinomas or carcinoids. Antibodies to basal cell keratins 14 and 17 also displayed positivity only in squamous cell carcinomas, although no correlation with the degree of differentiation could be observed. Keratin 16 appeared to be a marker of the squamous phenotype, rather than of hyperproliferation. The keratin 18 marker for columnar epithelial cells showed a reaction pattern opposite to that of the basal cell keratins, being extensively present in adenocarcinomas, small cell carcinomas and carcinoids, with less expression in squamous cell carcinomas. This study shows a correlation between the presence of type VII collagen and the basal cell keratins 14 and 17, and a negative correlation between these components and keratin 18. These findings are likely to be useful in identifying lung cancer subtypes.

Distribution patterns of type VII collagen in normal and malignant human tissues.

The distribution of basement membrane type VII collagen was detected immunohistochemically and compared in normal human organs and their neoplastic derivatives using monoclonal antibody LH7.2. In normal tissues, type VII collagen was found to be restricted to the basement membrane surrounding or underlying combined epithelia, such as those lining breast, prostate, and bronchus, which are composed of a basal and luminal cell layer, and stratified epithelia, such as larynx, esophagus, trachea, vagina, ectocervix, and epidermis. No type VII collagen was found in the "simple' epithelia lining the major part of the gastrointestinal tract (GI) tract, such as liver, stomach, and intestine, or around blood vessels, muscle, and nerve fibers, which are surrounded, however, by a basement membrane containing type IV collagen and laminin. When tested in benign and malignant local tumors, antibody LH7.2 showed staining patterns partly similar to those observed in the corresponding normal tissues. This resulted in a well-circumscribed positive reaction around ducts in carcinomas in situ of the breast, in benign prostate tumors, in pleomorphic adenomas, and in a negative reaction in tumors of the GI tract. Furthermore type VII collagen was predominantly seen in carcinomas with a squamous differentiation, such as squamous carcinomas of the lung, head and neck, vulva, and vagina. These results indicate that the presence of type VII collagen in malignant tumors is correlated with (squamous) differentiation rather than with the origin of the tumor. With tumor progression, an increased presence of type VII collagen, as compared with normal urinary bladder, was found in infiltrating transitional cell carcinomas. Thus, although in general invasive and metastatic tumors do not express extensively type VII collagen, exceptions to this rule exist in bladder cancer, squamous carcinomas of the lung, tumors of the head and neck region, female genital tract tumors, and in some adenocarcinomas of the breast.

Basal cell-specific and hyperproliferation-related keratins in human breast cancer.

In normal breast tissue and in noninvasive breast carcinomas, various keratin-14 antibodies were reactive predominantly with the basal/myoepithelial cell layer, although mainly in terminal and larger ducts luminal cells sometimes also were stained. A similar reaction pattern was found with an antibody directed against keratin 17, although this antibody was more often found negative than keratin 14 in the pre-existing myoepithelial cells in intraductal carcinomas. Furthermore antibodies reactive with hyperproliferation-related keratins 6 and 16 were used. One of these (LL025) was completely negative in normal breast tissue and noninvasive breast carcinomas. However 10% of the invasive carcinomas were diffusely or focally positive with this latter antibody, while in 18 of 115 cases of invasive breast carcinomas studied, a basal cell phenotype was detected. A relatively high concordance was found between the carcinomas immunostaining with the basal cell and the hyperproliferation-related keratins, but not between these markers and the proliferation marker Ki-67. This supports the conclusion that basal cells in breast cancer may show extensive proliferation, and that absence of Ki-67 staining does not mean that (tumor) cells are not proliferating.

Postnatal centralization of muscle fibre nuclei in centronuclear myopathy.

Postnatal centralization of muscle fibre nuclei, which were previously located subsarcolemmally, is described in a case of centronuclear myopathy (CNM) in a male patient with generalized muscle weakness since birth. A muscle biopsy was taken at the age of 11 months; no particular abnormalities were observed at this stage apart from an unusual variation in fibre size. A distinctly below average muscle fibre diameter, increased endomysial connective tissue, and features typical for CNM were found in a biopsy taken 9 yr later. Immunohistochemical studies using antibodies to desmin, vimentin, laminin and type IV collagen revealed altered staining patterns compared with normal fibres. The abnormalities in the patterns of cytoskeletal proteins point to a defective regulation of the composition and organization of the cytoskeletal network during development, paralleled by abnormalities in the extracellular matrix.

Detection of basement membrane components and basal cell keratin 14 in noninvasive and invasive carcinomas of the breast.

Using immunohistochemistry, the distribution patterns of basement membrane components type VII collagen (monoclonal antibody LH7.2), type IV collagen, and laminin were investigated in normal and malignant human breast tissue and compared with that of keratin 14 (monoclonal antibody LL002), which is expressed only by the basal (myoepithelial) cells in the secretory epithelia of the mammary gland. In normal breast tissue as well as in intraductal carcinomas, a more or less continuous basement membrane was observed at the epithelial stromal interface. Unlike laminin and type IV collagen, type VII collagen was not detected in the basement membrane of blood vessels. The keratin 14 antibody stained the basal cell layer of normal ducts and ducts with in situ cancer. In 85% of the invasive carcinomas no basement membrane or basal cells were detected. In 13 cases, however, laminin, type IV collagen, and/or type VII collagen were detected around tumor nests and individual tumor cells. Five of these tumors also showed a positive reaction with the keratin 14 antibody. In five cases keratin 14 expression was found without detectable basement membrane components. It is concluded that 18 of 103 invasive ductal breast carcinomas examined in this study exhibit a basal cell phenotype as determined from the expression of keratin and the deposition of basement membrane components.

Heterogeneous responses of B-cell tumours to anti-Ig and anti-idiotypic antibodies.

Anti-Ig antibodies can have two opposing effects on B-cell proliferation, resulting either in stimulation or inhibition. We have examined the proliferative response of 30 B-cell tumours to anti-Ig in the presence and absence of B-cell growth factor. Three reaction patterns were observed. In 12 cases a dose-dependent synergism between anti-Ig and B-cell growth factor was present in the induction of proliferation, in ten cases anti-Ig did not induce any response, and in eight cases anti-Ig suppressed the B-cell growth factor (BCGF)-induced proliferation. Similar responses to anti-Ig were found in the absence of BCGF. When these B-cell tumours were typed for expression of Ig isotypes, HLA class II antigens, several B-cell markers, activation markers, complement receptors, Fc receptors, cell size, and cell cycle phase, no correlation could be found with the proliferative response of these tumour B cells to anti-Ig. T cells or T-cell factors were not involved, because T-cell depletion did not change the tumour B-cell proliferative response to incubation with anti-Ig. The observed inhibition of proliferation did not correlate with the expression of Fc receptors, indicating the involvement of suppressor mechanisms other than the cross-linking of Fc receptors with surface immunoglobulins. Tumour B cells, for which monoclonal anti-idiotypic antibodies (MoAb anti-id) were available, responded to MoAb anti-id in the same way as they did to anti-Ig. In view of the treatment of B-cell malignancies with MoAb anti-id, the question of whether these responses in vitro correlate with in vivo clinical outcome of anti-id therapy is of interest. So far our data show that the proliferative response of B-cell tumours to anti-Ig or MoAb anti-id is heterogeneous and cannot be linked to phenotype, is T cell-independent, and is most likely an intrinsic property of the malignant cell.

Attachment of origins of replication to the nuclear matrix and the chromosomal scaffold.

We have investigated the attachment of DNA to the nuclear matrix and chromosomal scaffold in synchronized bovine liver cells. Label incorporated at the onset of the S phase remained preferentially associated with the matrix during the subsequent G1 phase and with a residual protein structure from dehistonized chromosomes during mitosis. On the other hand label incorporated during mid or late S phase was about equally distributed over the DNA molecule after a chase into the G1 phase. These results suggest that DNA is attached to the nuclear matrix and chromosome scaffolds by the origins of replication.