Monoclonal antibodies to laminin reveal the heterogeneity of basement membranes in the developing and adult mouse tissues.

Two monoclonal antibodies raised against laminin isolated from a mouse parietal yolk sac cell line were used for immunohistochemical studies of basement membranes of the mouse embryo and various fetal and adult tissues. No immunoreactivity with either of the two monoclonal antibodies could be detected in the preimplantation-stage embryos, although it has been shown that these embryos contain extracellular laminin reactive with the conventional polyclonal antilaminin antibodies. Reichert's membrane in early postimplantation stages of development reacted with the monoclonal antibody LAM-I but not with the antibody LAM-II. However, from day 8 of pregnancy onward the Reichert's membrane reacted with both antibodies. Basement membranes of the embryo proper were unreactive with both monoclonal antibodies until day 12 of pregnancy. By day 14 some basement membranes of the fetal tissues became reactive with one or both monoclonal antibodies, whereas others remained still unreactive. In the 17-d fetus and the newborn mouse most of the basement membranes reacted with both monoclonal antibodies, whereas others still reacted with only one. Similar heterogeneity in the immunoreactivity of basement membranes of various tissues was noted in the adult mouse as well. These results indicate that the immunoreactivity of laminin in the extracellular matrix changes during development and that the basement membranes in various anatomic locations display heterogeneity even in the adult mouse.

5-Hydroxyindoleacetic acid in the lumbar fluid: a specific indicator of spinal cord injury.

In cats, 19 days after the lower thoracic cord was injllred, the concentrations of 5-hydroxytryptamine and its metabolite 5-hydroxyindoleacetic acid in the lumbosacral cord and that of 5-hydroxyindoleacetic acid in the lumbar fluid decreased. At the same time the concentrations of these substances in the cord above the lesion and that of 5-hydroxyindoleacetic acid in the cisternal fluid was not significantly altered. Since high concentrations of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid are present in the human lumbosacral cord, it appears that the concentration of 5-hydroxyincdoleacetic acid in the lumbar fluid of animals and man reflects the biochemical changes of 5-hydroxytryptamine in the spinal cord.

Development of teratomas from embryos transplanted into outbred and inbred adult hamsters.

Six- to 8 1/2-day inbred MHA/SsLak and outbred Syrian golden hamster embryos and 14-day fetal lungs, testes, and portions of small intestine were transplanted into cheek pouches or under kidney capsules of adult recipients. Embryonic grafts gave rise to benign teratomas, irrespective of the age of the embryo, transplantation site, and the strain or stock of recipient. Fetal lung and testis grew little in extrauterine sites, whereas fetal intestine formed large mucus-filled cysts lined with proliferating and apparently functionally active epithelium.

Yolk sac carcinoma grown from rat egg cylinders.

Eight-day rat egg cylinders transplanted in toto under the kidney capsules of adult histocompatible recipients gave rise to small nodules composed of parietal yolk sac cells surrounded by Reichert's membrane-like material. These yolk sac cells could grow and give rise to malignant, transplantable tumors identical to mouse yolk sac carcinomas derived from teratocarcinoma. The sera of rats with yolk sac tumors contained elevated concentrations of alpha1 fetoprotein.

Isoelectric focusing of alpha-L-fucosidase from human embryonal carcinoma.

Isoelectric focusing profiles of alpha-L-fucosidase recovered from human embryonal carcinoma (EC) and seminoma were compared with those of mouse germ cell tumor-derived stem cells and some human somatic cell neoplasms in an attempt to determine whether EC cells could be used as a source of human basic isoelectric forms of the enzyme previously identified in normal and malignant mouse embryonic cells. alpha-L-Fucosidase activity in all human tumors was associated with isoelectric forms in the isoelectric point (pl) range between approximately 4.5 and 7, corresponding to the range seen in normal human tissues. The basic isoelectric forms (pl values, 7.5-9.5) that predominate in the embryonic isoelectric focusing pattern in mouse were not found in human neoplasms. The present data illustrate another difference between human and mouse EC and show that mouse EC cells are not a complete replica of equivalent human tumor cells.

Ultrastructural differentiation of a clonal human embryonal carcinoma cell line in vitro.

A cloned human embryonal carcinoma (EC) cell line 2102Ep derived from a testicular teratocarcinoma was characterized by means of electron microscopy and immunohistochemistry. These EC cells when plated at high cell density grow mostly as undifferentiated cells displayed relatively little pleomorphism. Eighty-five to 90% of these cells contain keratin in the form of peridesmosomal tonofilaments. Cell populations of the same clonal line plated at a low cell density contain, in addition to undifferentiated EC cells, large cells displaying complex cytoplasmic architecture, more complex junctions, and intracytoplasmic keratin in the form of bundles. Some of these cells also react with antibodies to human chorionic gonadotropin indicative of trophoblastic differentiation. Furthermore, some cells form "morules" which are multicellular aggregates composed of a core of EC cells and an attenuated, more differentiated outer cell layer. These data thus point out not only some similarities but also even more prominent differences between human and mouse EC cells.

Immunohistochemical localization of the mouse stage-specific embryonic antigen 1 in human tissues and tumors.

Normal human tissues and various human tumors were surveyed by immunohistochemical techniques for expression of the stage-specific embryonic antigen 1 (SSEA-1). The antibody reacted with many normal and neoplastic human tissues. In most instances, equivalent human and mouse tissues expressed SSEA-1; however, different tissue localization patterns were sometimes seen between these two species. Most SSEA-1-positive tumors originate from tissues that normally expressed this antigen; however, some breast and ovarian tumors are SSEA-1 positive, and these organs are SSEA-1 negative. SSEA-1-positive tumors were composed of both immunoreactive and nonreactive tumor cells. These data show that SSEA-1, initially defined as a mouse embryonic antigen, represents a heterogenetic antigen present in many normal human tissues. It is retained on many but not all neoplastic cells originating in these normal tissues and also appears on the surface of some tumor cells developing in SSEA-1-negative tissues.

Induction of testicular sarcomas in Fischer rats by intratesticular injection of nickel subsulfide.

Nickel subsulfide (Ni3S2) was injected in various amounts into the testis of adult Fischer rats for the study of the acute and chronic effects of Ni3S2 on testicular cells. Rats given injections of 0.6 to 10 mg of Ni3S2 developed an immediate inflammatory response at the site of injection, followed by a delayed, slowly evolving coagulation necrosis of seminiferous tubules and interstitial cells. The extent of testicular necrosis was dose dependent, but at doses of 5 or 10 mg of Ni3S2 the rats invariably developed subtotal destruction of the testis. The testis became atrophic, without regeneration of seminiferous tubules. No damage was seen in the other testis, and no systemic effects were noted. Malignant testicular neoplasms developed in 16 of 19 rats within 20 months after an injection of 10 mg of Ni3S2. These neoplasms were classified by light and electron microscopy as fibrosarcomas, malignant fibrous histiocytomas, and rhabdomyosarcomas. None of the testicular neoplasms was derived from germ cells or genital cord cells. The occurrence of rhabdomyosarcomas in the testis, an organ normally devoid of striated muscle, suggests that Ni3S2 induces malignant transformation of undifferentiated, pluripotential mesenchymal cells.

Differential expression of the zinc finger gene TCF17 in testicular tumors.

TCF17, the human homologue of the rat zinc finger gene Kid1, is highly expressed in neurons derived from the retinoic acid-treated human embryonal carcinoma (EC) cell line, NTERA-2. This differentiation-related up-regulation of TCF17 prompted us to investigate its expression during human spermatogenesis and in human testicular germ cell tumors considered to be precursors of EC. Expression of TCF17 increases as spermatogonia differentiate into spermatocytes, indicating that this gene is developmentally regulated during spermatogenesis. TCF17 mRNA levels are high in carcinoma in situ and in seminoma, a tumor derived from carcinoma in situ but still of low-grade malignancy. However, TCF17 expression is decreased in highly malignant EC. The differential regulation of TCF17 during neoplastic germ cell differentiation may be of predictive value in germ cell tumor diagnosis.

Functional pancreatic beta-cell line from SV40 T-antigen transgenic mouse.

Cell line IgSV195, derived from a pancreatic tumor that arose in an SV40 T-antigen transgenic mouse, retains certain morphological and physiological characteristics of pancreatic beta-cells throughout in vitro and in vivo passage. Insulin secretion is stimulated by exposure of these cells to fetal bovine serum and a combination of 3-isobutyl-1-methylxanthine and glutamine but not by concentrations of glucose in the physiological range. Insulin processing appears to be intact. Neither class I nor class II major histocompatibility complex (MHC) antigens are routinely expressed at the cell surface; however, MHC class I--but not class II--encoded gene products are detected after treatment with recombinant interferon-gamma (IFN-gamma) alone or in combination with tumor necrosis factor. Cytolysis of IgSV195 cells by SV40 T-antigen-specific H-2b-restricted lymphocytes is similarly dependent on IFN-gamma pretreatment. These results emphasize that SV40 T-antigen transgenic mice are likely sources of cell lines that retain their differentiated function in vitro. The IgSV195 cell line provides an accessible model in which to investigate the control of gene expression and function of pancreatic beta-cells.

Teratocarcinoma: neoplastic lessons about normal embryogenesis.

Germ cell tumors of the testis and the ovary have been studied extensively in humans and experimental animals. Murine teratocarcinomas proved to be one of the best experimental models for elucidating the histogenesis of these tumors and the nature of their undifferentiated stem cells. These spontaneous and experimentally induced tumors, especially those produced from early postimplantation stage embryos, provided a wealth of data about the differentiation of tumor stem cells and the regulation of their growth. This made it possible to draw parallels between the teratocarcinoma cells and their normal equivalents in the embryo. Cumulative data indicate that neoplastic development of murine embryonic cells is just one of the possible ontogenic pathways these cells can take while proliferating in various developmental fields. The malignancy of teratocarcinoma stem cells is determined genetically but can be regulated epigenetically. Development of stem cells in murine teratocarcinomas parallels events in the normal embryo, suggesting that events in the tumor have their normal regulatory counterparts in the embryo proper. The study of early embryos has provided data relevant for oncology, while the study of murine teratocarcinoma helped elucidate some basic developmental events occurring normally in the embryo.

Detection of plaque-forming cells by a latex bead technique.

A new latex bead technique for measuring the plaque-forming cell (PFC) responses to bacterial antigens is described. This technique has been designed for the study of antigens that cannot be readily coated onto SRBC but may also used for antigens that adsorb onto SRBC as well. Application of the latex based technique for the study of PFC response of hamsters to Treponema reiter antigen is described in detail. Using SIII, an antigen that readily adsorbs to SRBC, we have compared the latex bead technique and the conventional SRBC-PFC technique and found that the latex bead technique is more sensitive than the conventional technique. The technique can be used for direct and indirect PFC assays. Technical details for the optimal performance of the latex bead PFC assay are outlined.

Evaluation of biological response modifiers in the enhancement of tumor uptake of technetium-99m labeled macromolecules. A preliminary report.

Imaging tumors with radioactive monoclonal antibodies remains attractive but continues to be challenging. With the hypothesis that the use of biological response modifiers (BRMs) may augment the tumor uptake, technetium-99m(99mTc)-labeled tumor necrosis factor (TNF) and nuclear histone specific TNT-1-F(ab')2 were evaluated in tumor bearing mice given a single dose of interferon (IFN). Ukrain or pokeweed mitogen as BRMs. As early as 1.5 h post injection (p.i.) of the radioactive macromolecules, the absolute tumor uptake (% administered dose/g) of each agent was enhanced (e.g., TNF, control = 1.8 +/- 0.4, Ukrain = 3.2 +/- 0.5, P = 0.006) and tumor to muscle ratios were elevated (e.g., TNF, control a 4.1 +/- 2.2, interferon 8.3 +/- 2.7, P = 0.01). The absolute tumor uptake remained practically unchanged at 4 h p.i. Generally with BRMs, the blood clearance was rapid and tumor/blood ratios and tumor/muscle ratios were higher than in the control group, increasing to greater than 200% for IFN as a BRM. The early enhancement in tumor uptake of macromolecules, leading to excellent delineation of tumors by scintigraphy is highly encouraging and warrants further studies to explore the full potential of BRMs.

Myeloid metaplasia presenting as a breast mass.

A case of myeloid metaplasia presenting as an isolated breast mass in an elderly woman is described. The breast tumor developed 16 years after the initial diagnosis of myelofibrosis and was the only clinically significant sign of the disease necessitating treatment. Ultrastructural examination demonstrated that the lesion consisted of megakaryocytes and immature myeloid cells. This rare lesion, one of a number of manifestations of hematopoietic diseases involving the breast, should be included in the differential diagnosis of stromal breast lesions, especially those containing giant cells.

Protease treatment combined with immunohistochemistry reveals heterogeneity of normal and neoplastic basement membranes.

Heterogeneity of normal tissue and neoplastic basement membranes was investigated immunohistochemically with monoclonal antibodies and polyclonal antisera to laminin and collagen type IV. Cryostat sections of normal and neoplastic human tissues were digested with bacterial protease or trypsin. The duration of digestion and the concentration of enzyme were varied to determine whether laminin and collagen type IV could be removed differentially from basement membranes from distinct anatomic sites. After digestion, the residual antigenicity of glycoprotein was assessed immunohistochemically. Laminin could be removed more easily from all tissues than could collagen IV, and also much more easily from malignant tumors than from benign tumors or normal tissues. On the basis of susceptibility to proteolytic digestion, basement membranes from normal human tissues were classified as susceptible (e.g., heart and smooth muscle of gastrointestinal tract and uterus), moderately resistant (e.g., nerve, skeletal muscle, epithelial basement membrane of skin, smooth muscle of arteries), and very resistant (e.g., glomerulus). Differential susceptibility to proteolytic digestion most likely reflects quantitative and possibly also qualitative differences in the composition of basement membranes.

Immunoblotting of keratin polypeptides extracted from tissues preserved in standard histologic fixatives.

Cytoskeletal polypeptides from fresh placental tissue, tissue stored at -30 degrees C, and tissue fixed in 10% buffered formalin, Bouin's solution, and Carnoy's solution were extracted, separated by electrophoresis, and immunoblotted using monoclonal antibodies immunoreactive with keratin polypeptides. Storage of the placental tissue at -30 degrees C, or fixation in Carnoy's solution did not alter the extractability, migration pattern, or immunoreactivity of the keratin polypeptides. Keratin polypeptides could not be adequately demonstrated in extracts prepared from formalin- or Bouin's solution-fixed tissues. Several unmasking procedures used on tissues before extraction and on nitrocellulose blots before application of primary antibodies failed to unmask keratin polypeptides, either in Coomassie blue-stained gels or in immunoblots reacted with anti-keratin antibodies. These data indicate that Carnoy's solution is the fixative of choice for tissues in which electrophoretic and immunoblotting analyses of keratin polypeptides might be required.

Lectin histochemistry of mouse vagina during the estrous cycle.

Estrous cycle-related histochemical changes in the vaginal epithelium of sexually mature female mice were studied with 30 fluorescein isothiocyanate (FITC)-labeled lectins. On the basis of the staining pattern the lectins were divided into five groups: I, seventeen lectins that reacted with mucinous surface layer of proestrus. This group comprised two subgroups: Ia, seven lectins that reacted exclusively with the mucinous layer, and Ib, ten lectins that reacted with mucinous cells and the underlying squamous epithelium of proestrus; II, two lectins that reacted with squamous epithelium of proestrus only but were unreactive with mucinous cells; III, three lectins that reacted in a phase-specific manner with squamous epithelium; IV, six lectins that showed increased luminal surface reactivity in diestrus and/or metestrus; and V, eleven lectins that were unreactive with vaginal epithelium. These data indicate that the cyclic changes in the morphology of the vaginal epithelium are accompanied by distinct lectin reactivity patterns.

Mixed glycosidase pretreatment reduces nonspecific binding of antibodies to frozen tissue sections.

Indirect immunohistochemical studies of frozen mouse tissues with mouse monoclonal antibodies yield, in general, suboptimal results primarily because of indiscriminate binding of secondary antibody to all mouse immunoglobulins, i.e., to the monoclonal reagent and to endogenous immunoglobulin nonspecifically trapped in the tissue. To reduce this nonspecific staining, frozen sections of mouse kidney were treated enzymatically. Optimal results were obtained following a 2 hr treatment with 20 mg/ml of mixed glycosidases (MG). This treatment reduced the nonspecific background staining of the interstitial spaces and blood vessels, but did not affect the reactivity of structurally bound immunoglobulin G (IgG) in the glomeruli or alter the reactivity of mouse renal tissue to the monoclonal antibody that recognizes an oligosaccharide antigenic determinant (SSEA-1). Eluates from enzyme-treated frozen tissue sections contained normally immunoreactive IgG in the form of dimers. These data indicate that MG treatment of frozen sections could be safely used to reduce the content of nonstructurally bound immunoglobulins in frozen tissues and thus improve the visualization of specific monoclonal antibody binding.

Glycoproteins of mouse vaginal epithelium: differential expression related to estrous cyclicity.

We used lectin overlay blotting and SDS-PAGE to analyze the estrous cycle-specific expression of mouse vaginal epithelial glycoproteins. Seven lectins chosen for their differential carbohydrate-binding specificity revealed 15 glycoproteins that showed cycle-related expression. Each lectin had a unique binding pattern different from the patterns revealed by other lectins. However, several estrous cycle phase-specific glycoproteins reacted with more than one lectin. The most prominent of these glycoproteins (M(r) 92-95 KD) was weakly expressed in late diestrus and fully expressed only in proestrus, coincident with the transformation of two superficial layers of vaginal squamous epithelium into mucinous cuboidal cells. Electron microscopic lectin histochemistry revealed the glycoproteins in the mucinous granules of surface cuboidal cells and in the lumen of the vagina. Our results illustrate the complexity of glycoconjugate synthesis in mouse vagina and reveal the distinct cycle-specific patterns of individual glycoprotein expression. These cyclic glycoproteins could serve as vaginal biochemical markers for the specific phases of the estrous cycle.

Heterogeneity of basement membranes of the human genitourinary tract revealed by sequential immunofluorescence staining with monoclonal antibodies to laminin.

We used monoclonal antibodies specific for human laminin to analyze immunohistochemically the heterogeneity of the basement membranes in various parts of the genitourinary tract. By indirect immunofluorescence microscopy we show that antibody 3H11 reacts with all epithelial basement membranes in the kidneys, testes, epididymis, prostate, uterus, oviduct, and ovary, as well as the smooth muscle cells, blood vessels, and nerves. Antibody 4E10 reacted with most epithelial basement membranes in these organs but was unreactive with the basement membranes of peripheral glomerular capillary loops and the basement membranes of the oviductal mucosa, seminiferous tubules, straight tubules, and rete testis. Hilar seminiferous tubules were reactive with 4E10. In contrast to 3H11, which reacted with all vascular, subendothelial, and muscular basement membranes, 4E10 reacted only with the subendothelial basement membrane of capillaries and veins. The difference in the distribution of epitopes could be demonstrated in tissue sections sequentially reacted with two monoclonal antibodies, but only if the antibody of restricted reactivity (4E10) was used first. These data show that the heterogeneous expression of distinct epitopes of laminin in basement membranes can be demonstrated in the same tissue section by sequential staining. This heterogeneity of basement membranes most likely reflects conformational differences in the expression of epitopes on the laminin molecule in various anatomic structures.