Biomedical subjects

E B Lane

Publications and source records attributed to E B Lane.

At least 109 records · Page 6Linked to original sources

PubMed1991

Patterns of cytokeratin expression in human gingival epithelia.

Specimens of human gingiva were collected from teenage and adult subjects and frozen sections were stained with an extensive panel of monoclonal antibodies with defined specificities for individual cytokeratins. The results indicated different and distinctive patterns of keratin expression by the oral gingival, oral sulcular and the junctional epithelia. It was observed that epithelium with staining characteristics of sulcular epithelium extended over the gingival crest onto the oral surface of the gingiva. Junctional epithelium showed the unusual pattern of co-expression of keratins typical of the stratifying and of the simple epithelial phenotypes. The patterns of gingival keratin expression are compared with those of other mucosal epithelia. The findings are discussed in relation to mechanisms that may determine or influence the junctional epithelial phenotype.

Adolescent↗

PubMed1991

Cytokeratins, smooth muscle actin and vimentin in human normal salivary gland and pleomorphic adenomas. Immunohistochemical studies with particular reference to myoepithelial and basal cells.

The distribution of immunostaining in normal major salivary gland and in 12 pleomorphic adenomas was studied using monospecific monoclonal antibodies to a number of cytokeratins, including cytokeratin 14, to smooth muscle actin and vimentin. A number of these antibodies enabled a distinction to be made between structural components of the normal gland, and to relate this to the different structures of pleomorphic adenomas. In the normal gland, the luminal duct cells expressed cytokeratins 7, 8, 18 and 19. Three antibodies were of particular value for the characterization of normal myoepithelial and basal cells; while the antibody to smooth muscle actin and the cytokeratin antibody Ks8.12 mutually exclusively stained the myoepithelial (basket) cells and the basal duct (light) cells, respectively, the recently established monospecific antibodies to cytokeratin 14 showed specific immunostaining with both cell types. These three antibodies left luminal cells virtually unstained. Ck 13 was found occasionally in single luminal excretory duct cells. Antibodies to cytokeratins 1/2, 10 and 10/11 did not show any staining in the normal gland. In the pleomorphic adenomas, the staining pattern of the two-layered tubular formation resembled that of the normal gland ducts: tumour luminal cells showed the characteristic, although more irregular, expression of cytokeratins 7, 8, 18 and 19; the outer cells resembled normal ductal basal cells with their anti-cytokeratin 14/Ks8.12-epitope staining and in that they virtually lacked staining for smooth muscle actin. Trabecular formations and cells in myxoid areas were reactive with Ks8.12 and for cytokeratin 14, occasionally also for cytokeratins 7, 18 and 19. Epidermoid cell islets expressed mainly cytokeratin 14 and inconsistently the squamous epithelial cytokeratin 13 and the epidermal cytokeratin 10/11. Vimentin was found in cells of myxoid areas. The results support the postulate that some of the normal duct basal cells act as reserve cells and can give rise to tumour formation with a primitive myxoid or trabecular pattern and a more differentiated tubular or epidermoid configuration.

Actins↗

PubMed1991

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.

Antibodies, Monoclonal↗

PubMed1991

Cytokeratin expression patterns in metastatic transitional cell carcinoma of the urinary tract. An immunohistochemical study comparing local tumor and autologous metastases.

The cytokeratin (CK) expression patterns of local, ie, primary or recurrent, high-grade-malignant transitional cell carcinomas (TCCs) of the human urinary tract and autologous lymphogenic and hematogenic metastases (n = 33) were compared. Special attention was paid to CK expression in the tumor invasion front and other areas where tumor-stroma interaction occurred to visualize cell populations with a metastatic phenotype. For this purpose, polypeptide-specific monoclonal antibodies to CKs 4, 7, 8, 10, 13, 14, 16, 17, 18, and 19 were used, employing the immunoperoxidase method. Results show that: 1) An increased expression of CK8 and CK18 is seen in the TCC tumor cells at the interface with peritumoral stroma in the tumor invasion front and with intratumoral stroma ('interface phenomenon'). Other than reflecting a quantitative change, this phenomenon might be explained by unmasking of CK8 and CK18 epitopes occurring in these regions. 2) Although in general the expression of CK13 in local TCC is decreased with increase of histopathologic parameters for progression, ie, grade and stage, an extensive proportion of CK13-positive tumor cells still can be found in some TCCs, even in metastases. 3) Morphologically recognizable types of aberrant differentiation in TCC, i.e., pseudosarcomatous or squamous differentiation and marked loss of differentiation, show altered expression of many of the CKs studied.

Carcinoma, Transitional Cell↗

PubMed1990

Retrovirus-mediated transgenic keratin expression in cultured fibroblasts: specific domain functions in keratin stabilization and filament formation.

With retrovirus-mediated gene transfer, we used intact and deleted keratin proteins to investigate the molecular basis of intermediate filament function. Three levels of assembly show a different stringency for the involvement of individual keratin domains: protein accumulation requires the alpha helix domains; stable filament formation additionally requires both N- and C-terminal domains of either one of the two interacting keratins, suggesting that head to tail homotypic interaction is important for effective elongation; and higher order organization of the cytoplasmic network depends on correct type I-type II pairing of keratins. The presence of two distinct interaction sites along potentially different axes may explain the characteristic morphology of keratin intermediate filament networks.

Animals↗

PubMed1990

An investigation of cytokeratin expression in skin epithelial cysts and some uncommon types of cystic tumours using chain-specific antibodies.

The differentiation state of skin epithelial cysts and some uncommon types of epithelial skin tumours was investigated by immunohistochemical staining, mainly using cytokeratin (CK) polypeptide-specific monoclonal antibodies. Samples of interfollicular epidermis, hair follicles and eccrine sweat glands were included as reference tissues. The CK reactivity in epidermoid cysts and milia is not restricted to CKs involved in epidermal-type differentiation, i.e. CK1, 5, 10 and 14, but in addition CK16, a hyperproliferative keratinocyte marker is suprabasally expressed. CK1 and 10 are other prominent suprabasal markers, while CK14 seems to be preferentially expressed in the basal cell layer. Of the non-epidermal CKs, only CK4 was focally or more extensively detected in about 50% of the cases. In terms of CK reactivity, keratinization of trichilemmal cysts corresponds to the keratinization of the anagen-phase hair follicle in the isthmus. The CK reactivity is again restricted to CK1, 5, 10, 14 and 16. However, the CK1 as well as CK10 reactivity is subject to serious limitations, since both CKs were only convincingly observed in foci of terminal differentiation. Eccrine hydrocystoma obligatorily expresses a complex CK set, including CK7, 8, 14, 18 and 19. This CK set perfectly corresponds to the CK composition observed in acini of eccrine sweat glands. In addition, a discontinuous CK4 and 16 reactivity was seen in about 50% of the sites, while CK1 and 10 displayed a strictly focal appearance. On the other hand, syringoma produces in its distinct structures, a CK pattern reminiscent of the one observed in eccrine sweat gland ducts and includes CK1, 5, 10, 14, 16 and 19.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

PubMed1990

Heterogeneity in spinal radial glia demonstrated by intermediate filament expression and HRP labelling.

Considerable evidence indicates that radial glial cells play an active role in guiding growing neurites during development of the vertebrate CNS. In this paper we describe subpopulations of radial glial in the spinal cord of the axolotl. Amphibians maintain radial glia throughout life, and subpopulations are described using anatomical criteria following filling of individual cells with horseradish peroxidase and immunocytochemical staining with a range of intermediate filament antibodies. Radial glial cells in specific regions of the spinal cord stain with a range of antibodies specific to human keratins 8 and 18, and to glial fibrillary acid protein (GFAP). Some of these antibodies show selective localized to specific regions of individual glial cell processes. Immunoblotting analysis indicates that two keratins are present in the axolotl CNS corresponding to the two earliest embryonic keratins of vertebrates, keratin 8 and 18. Comparisons of molecular weight indicate that these may correspond to keratins identified in Xenopus laevis, the genes of which have been cloned. Axolotl GFAP is also identified in Western blots and may be present in two forms of differing molecular weight. These results are discussed in terms of the likely role of radial glial cells, and comparisons are drawn between the keratin and GFAP types seen in the axolotl spinal cord and of those in other vertebrate groups.

Ambystoma↗

PubMed1990

Localization of the gene for human simple epithelial keratin 18 to chromosome 12 using polymerase chain reaction.

Many human genes encoding keratin intermediate filament proteins are clustered on chromosomes 17 (the type I genes) and 12 (the type II genes). Some have not yet been localized, notably the genes for the primary embryonic keratins 8 and 18, normally expressed in simple epithelia: this is because the numerous pseudogenes for these keratins have made it difficult to identify the true functional gene in each case. Through the use of human-specific primers from within introns of the published gene sequence for human type I keratin 18, human genomic DNA has been specifically amplified using the polymerase chain reaction. A single reaction product was obtained. DNA from a characterized series of mouse-human somatic cell hybrid lines was tested for the presence of sequences able to initiate the chain reaction from these primers, and the presence or absence of this genomic DNA PCR product allowed us to assign a gene for human keratin 18 to chromosome 12 unambiguously. This differs from the location of other human type I keratins on chromosome 17 and may indicate the early divergence of the genes for stratifying cell keratins from that of simple, or embryonic, keratin 18.

Animals↗

PubMed1990

Antibody markers of basal cells in complex epithelia.

In the course of immunohistochemical studies it has become apparent that there is a distinct phenotype of keratin expression that is shared by basal epithelial cells in a variety of different tissues. A basal cell can be defined as a cell in contact with a basal lamina but with no free luminal surface; this distinguishes it from a simple epithelial cell, which has a free luminal surface as well as basal lamina contact, and from stratifying suprabasal keratinocytes, which have neither basal lamina contact nor free luminal surface. All basal cells, whether they are in glandular ductal or secretory epithelia, or in stratified squamous epithelia, express the keratin pair K5 and K14. In this paper we describe monoclonal and polyclonal antibodies that are monospecific for both keratins 14 and 5 or are specific for denaturation-sensitive epitopes unique to basal cells, including five new monoclonal antibodies: LL001 and LL002 (to keratin 14), 2.1.D7 (to keratins 5, 6 and 8), and LH6 and LH8 (conformation-specific basal cell markers). These antibodies have been used to monitor the distribution of the basal cell phenotype and to demonstrate the expression of keratins 5 and 14 in this cell type, in both stratified epithelia and mixed epithelial glands. The consistent association of this keratin pair with basal cells suggests a possible specific function for these keratin in reinforcing epithelia under physical stress, whilst expression of these keratins may conflict with the differentiated functions of most simple epithelial cells.

Amino Acid Sequence↗

PubMed1990

Distribution of cytokeratin polypeptides in human transitional cell carcinomas, with special emphasis on changing expression patterns during tumor progression.

The expression of cytokeratin (CK) polypeptides was studied in 59 transitional cell carcinomas (TCC) of the urinary tract of different grade and stage. Using a panel of 14 polypeptide-specific monoclonal CK-antibodies we identified immunohistochemically 8 different CKs separately, ie, CKs 4, 7, 8, 10, 13, 14, 18, and 19, while in immunoblotting studies CK5 expression was detected indirectly by using the antibody RCK102, recognizing CK5 + 8. In low-grade TCCs (G1-G2), the CK distribution was comparable to that in normal urothelium, however with a variable expression of CK13 in the different tumors and a uniform distribution of CK7. In higher-grade TCCs (G3), a decrease in CK13 expression was observed, particularly in the areas of muscle invasion. Furthermore, the appearance and increasing expression of CK14 (not present in normal urothelium or G1 TCCs) with higher grade and stage was striking. With tumor progression changes in epitope configurations of CK8 and CK18 were detected, as concluded from immunohistochemical assays with the panel of monoclonal antibodies for each of these two CKs. In extreme cases this resulted in differential staining patterns of the invasive and noninvasive components within one tumor. In 7 of 32 G3 TCCs, some of which showed areas with evident squamous differentiation, a decrease in the expression of CK7 and/or CK8 was seen. We conclude that tumor progression in TCCs is associated with discrete changes of CK expression, which can be detected using monoclonal antibodies.

Antibodies, Monoclonal↗

PubMed1990

Embryonic simple epithelial keratins 8 and 18: chromosomal location emphasizes difference from other keratin pairs.

The keratins 8 and 18 of simple epithelia differ from stratified epithelial keratins in tissue expression and regulation. To examine the specific properties of human keratin 8, we cloned and sequenced the cDNA from a placental mRNA expression library and defined the optimum state of such clones for expression in bacterial plasmid vectors. Using the polymerase chain reaction we identified and sequenced three introns and located the single active gene for keratin 8, out of a background of 9 to 24 pseudogenes, on chromosome 12. This chromosome contains several genes for type II keratins and also the gene for keratin 18, the type I keratin that is coexpressed with keratin 8. This location of both members of a keratin pair on a single chromosome is thus far unique among the keratin genes; it is consistent with the hypothesis that keratins 8 and 18 may be closer to an ancestral keratin gene than the keratins of more highly differentiated epithelia.

Amino Acid Sequence↗

PubMed1990

Vimentin and keratin are expressed in the neurogenic tissue of the rabbit embryo during primary neurulation.

Against the commonly held belief that differential expression of keratins is a sign of neurogenic commitment amongst ectodermal cells of the early vertebrate embryo we show here that the same keratins (8 and 18) are expressed in the epidermal ectoderm and the neurectoderm throughout primary neurulation of the early rabbit embryo, i.e. between 8.5 and 11 days post conceptionem (d.p.c.). However, keratin expression decreases during this developmental period and, by the time primary neurulation is completed, keratin expression is virtually absent in the cells of the neural tube. Vimentin expression is weak, at first, but increases in a reciprocal manner as compared to the decreasing keratin expression until it has reached a high and stable level of expression in the established neural tube of the 10 to 11 day old rabbit embryo.

Animals↗

PubMed1990

Use of keratin antibodies in tumor diagnosis.

The tissue specific expression shown by intermediate filament proteins, their ease of extraction and their antigenicity has led to the use intermediate filament antibodies in diagnostic pathology, particularly antibodies to keratin intermediate filaments because of the predominant involvement of epithelia in cancers. We review the principles of differentiation-specific keratin expression and detail 100 of the best-known monoclonal antibodies to keratins which are currently in use: in many circumstances antibodies can now be reliably used as in situ markers of keratin expression. We also suggest a database scheme for better dissemination of information on available monoclonal antibodies to keratins in the future.

Antibodies, Monoclonal↗

PubMed1989

Transient expression of simple epithelial keratins by mesenchymal cells of regenerating newt limb.

Structural proteins of the intermediate filament family are an early indicator of differentiation before organogenesis becomes apparent. Keratin intermediate filaments are characteristically expressed only by epithelial and not by mesenchymal cells. Here we show, using monoclonal antibodies, a transient expression of the keratin pair 8 and 18 in a population of mesenchymal cells in the regenerating newt limb, specifically in the undifferentiated progenitor cells (blastemal cells) which give rise to the new tissues. These keratins are also expressed in cultured limb cells that can differentiate into muscle. In contrast no reactivity with anti-keratin 8 and 18 antibodies was observed in the newt limb bud at an early stage of development, indicating a molecular difference between the developing and regenerating limb. The molecular weights of the newt proteins detected by these antibodies are very similar to those of human keratins 8 and 18, further supporting the immunocytochemical evidence that the newt homologs of these keratins are expressed in blastemal cells. This is the first demonstration of keratin expression in mesenchymal progenitor cells in an adult animal.

Animals↗

PubMed1989

Keratin 19: predicted amino acid sequence and broad tissue distribution suggest it evolved from keratinocyte keratins.

The type I keratin 19 is unusual in its tissue distribution in that under normal circumstances it does not seem to be restricted, as the other keratins are, to expression in either stratified or simple epithelia. In addition to the previously reported distribution of keratin 19 in human tissues, we have observed keratin 19 in epidermal basal cells, in a defined region of the hair follicle, and in nipple epidermis. We noticed that expression of keratin 19 appears to be especially characteristic of regions of labile or variable cellular differentiation as indicated by the presence of multiple keratin phenotypes in close proximity to each other. Using a monoclonal antibody recognizing keratin 19 (LP2K) to screen a human placenta cDNA expression library, we have isolated, cloned, and sequenced cDNA coding for full-length human keratin 19, as confirmed by its reactivity with several other known anti-keratin 19 monoclonal antibodies and by the near identity of its sequence with that of the bovine keratin 19 homologue. This similarity extends to both proteins being truncated at the C-terminal end to only 13 amino acids beyond the rod domain. Although the amino acid homology over the N-terminal and helical rod domains is particularly high, the human and bovine proteins diverge substantially over the short C-terminal domain, which suggests that this region has no conserved function. Comparison with other type I keratins indicates that the closest evolutionary neighbors of keratin 19 are keratinocyte keratins, probably 13 and 14, and not the simple epithelial keratin 18. Assessing the histochemistry and sequence data together, we propose that the cell may use this apparently deficient keratin as a "neutral" keratin. While unimpaired in its ability to polymerize (keeping the cell integrated into the epithelial sheet via filament-desmosome networks), keratin 19 expression does not irrevocably commit a cell to any one of the local differentiation options. Such predicted differentiational flexibility may also imply vulnerability to transformation.

Amino Acid Sequence↗

PubMed1989

Expression of intermediate filament proteins in fetal and adult human lung tissues.

The expression patterns of intermediate filament proteins in fetal and normal or nonpathological adult human lung tissues are described using (chain-specific) monoclonal antibodies. In early stages of development (9-10 weeks and 25 weeks of gestation) only so-called simple cytokeratins such as cytokeratins 7 (minor amounts). 8, 18 and 19 are detected in bronchial epithelial cells. At later stages of development, the cytokeratin expression patterns become more complex. The number of bronchial cells positive for cytokeratin 7 increases, but basal cells in the bronchial epithelium remain negative. These latter cells show, however, expression of cytokeratin 14 in the third trimester of gestation. Developing alveolar epithelial cells express cytokeratins 7, 8, 18 and 19. In adult human bronchial epithelium cytokeratins 4 (varying amounts), 7, 8, 13 (minor amounts), 14, 18 and 19 can be detected, with the main expression of cytokeratins 7, 8, and 18 in columnar cells and the main expression of cytokeratin 14 in basal cells. Vimentin is detected in all mesenchymal tissues. In addition, fetal lung expresses vimentin in bronchial epithelium, however, to a lesser extent with increasing age, resulting in the expression of vimentin in only few scattered bronchial cells at birth. Also in adult bronchial epithelium the expression of vimentin is noticed in part of the basal and columnar epithelial cells. Desmin filaments, present in smooth muscle cells of the lung, appear to alter their protein structure with age. In early stages of development smooth muscle cells surrounding blood vessels are partly reactive with some cytokeratin antibodies and with a polyclonal desmin antibody. At week 9-10 and week 25 of gestation a monoclonal antibody to desmin, however, is not reactive with blood vessel smooth muscle cells but is only reactive with smooth muscle cells surrounding bronchi. With increasing age the reactivity of cytokeratin antibodies with smooth muscle cells in blood vessels decreases, while the reactivity with the monoclonal desmin antibody increases. Our results show that during differentiation profound changes in the intermediate filament expression patterns occur in the different cell types of the developing lung.

Antibodies, Monoclonal↗

PubMed1989

Cytokeratin expression of the odontogenic epithelia in dental follicles and developmental cysts.

The patterns of cytokeratin expression in the epithelium of 5 dental follicles, 7 dentigerous cysts, 5 odontogenic keratocysts, 3 nasopalatine cysts and an epidermoid cyst have been studies using a panel of monoclonal antibodies. The epithelium of dental follicles and of developmental odontogenic cysts strongly expressed keratins 5 and 19 and showed weaker expression of keratins typical of stratified non-cornified and of simple epithelia. Staining with mAbs against the latter keratins varied with the degree of epithelial differentiation. Nasopalatine cysts strongly expressed simple epithelial keratins and the epidermoid cyst strongly expressed a marker of cornification. Odontogenic cysts thus appear to differ in their pattern of keratin expression from other oral developmental cysts and all derivatives of odontogenic epithelia appear to share similar basic patterns of cytokeratin expression.

Antibodies, Monoclonal↗

PubMed1989

Keratin expression in human mammary epithelial cells cultured from normal and malignant tissue: relation to in vivo phenotypes and influence of medium.

The luminal and basal epithelial cells in the human mammary gland can be distinguished in tissue sections on the basis of the pattern of keratins they express. Moreover, the invasive cells in primary carcinomas show a keratin profile that corresponds to that of the dominant luminal cell (7, 8, 18, 19). When homogeneous populations of luminal epithelial cells from milk or from breast cancer metastases are cultured the profile of keratin expression seen in vivo is maintained. We have therefore used monospecific antibodies reactive with individual keratins to examine the phenotype of cells cultured in three different media from reduction mammoplasty tissue that contains both luminal and basal cells. The phenotype of cells cultured from primary breast cancers in one of these media (MCDB170) has also been examined. In characterizing cell phenotypes, antibodies to a polymorphic epithelial mucin (PEM) expressed in vivo by luminal cells, and to smooth muscle (a) actin, expressed in vivo by basal cells, have also been used. Our results show that proliferation of different cell phenotypes is selected for in different media. In milk mix (MX) developed for growth of luminal cells from milk, only the luminal cell phenotype proliferates (for only 1 or 2 passages). In medium MCDB 170, which was developed for long-term growth of human mammary epithelial cells from reduction mammoplasty organoids, cells from the basal layer proliferate, while in MM medium the basal phenotype dominates, but a few cells with the luminal phenotype are found. Around passage 3, in medium MCDB 170, most cells senesce and a subpopulation of cells proliferates on further passage. These cells retain expression of the basal epithelial keratins but also express some features characteristic of luminal epithelial cells, suggesting that the basal layer may contain a stem cell that can develop along the luminal lineage. In culture, however, they do not express keratin 19, which in vivo is a feature of the fully differentiated luminal cell. The cells cultured from primary breast cancer in medium MCDB 170 have a similar keratin profile to that of the normal cells cultured in this medium. They do not express keratin 19, even though the invasive cells in primary cancers homogeneously express this keratin in vivo. The invasive phenotype, which in its keratin profile corresponds to the differentiated luminal cell and that of the metastatic cancer lines, cannot be cultured from primary breast cancers using MX, which supports proliferation of the corresponding normal cell.

Breast↗