Surface biochemical changes accompanying primary infection with Rous sarcoma virus. II. Proteolytic and glycosidase activity and sublethal autolysis

The salubrious effect of tamoxifen [correction of Tamaxifen] on serum marker enzymes, glycoproteins, and lysosomal enzymes level in breast cancer woman

Tumour markers correlate strongly with prognosis based on tumour burden and surgical resectability. If chemotherapy is extremely effective in certain stage of the disease, the sensitive marker may be of great use in monitoring disease response and drug treatment. Hence, this study was launched to evaluate the changes in tumour marker enzymes like lactate dehydrogenase (LDH), glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase, and acid phosphatase in before and after 3 and 6 months tamoxifen treated breast cancer patients. In addition, the changes in serum glycoproteins viz., hexose, hexosamine, and sialic acid and lysosomal enzymes such as N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, and beta-D-glucuronidase were analysed in these patients. These values were compared with their age matched healthy control subjects. At 6 months evaluation, the tamoxifen treated postmenopausal breast cancer women showed a statistically significant decreased (p < 0.001, 0.05 respectively) levels of LDH, SGOT, SGPT, alkaline and acid phosphatases than their baseline values. Similarly, the levels of hexose, hexosamine, and sialic acid and N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, and beta-D-glucuronidase were decreased significantly (p < 0.001) in tamoxifen received postmenopausal women. The result of this study suggested that tamoxifen potentially retard the metastasis of breast cancer as well as the bone demineralisation in postmenopausal breast cancer women. Thus, tamoxifen may also have its antitumour activity through its beneficial effects on tumour marker enzymes and serum proteins in breast cancer women.

Neoplastic alteration of a membrane-associated sialidase of rat liver

Rat liver particulate fraction contains two types of membrane-associated and gangliosides-hydrolyzing sialidase, which have been shown to be identical to two membrane-associated sialidases of rat brain (I and II) chromatographically, immunologically and in substrate specificity. Chromatography on AH-Sepharose 4B of the membrane sialidases of rat primary hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (MeDAB) further revealed that hepatocarcinogenesis induces a marked decrease in sialidase II but no decrease in sialidase I. Using antisera against sialidases I and II of rat brain, immunoprecipitation studies of the solubilized particulate fractions of rat liver and MeDAB-hepatoma gave results similar to those obtained chromatographically. Using the same immunological technique, sialidase II but not sialidase I was found to be decreased in AH109 A hepatoma and in regenerating and fetal liver.

Collagen breakdown during acute lung injury

Injury to the capillary endothelium and to alveolar epithelial cells of the lung may result in damage to the underlying collagen of the extracellular matrix. To examine this possibility, whole body irradiation, bleomycin injections, and exposure to hyperoxia were used to induce various types of lung damage in mice. The morphology of the lung and the cellular and protein content of bronchoalveolar lavage fluid were used to assess injury. Collagen breakdown was assessed from the hydroxyproline concentrations in bronchoalveolar lavage fluid. When lung cell injury was observed, protein leaked in to alveoli and hydroxyproline was detected in bronchoalveolar lavage fluid. An increase in hydroxyproline followed endothelial damage by irradiation and was greatly increased when type 1 epithelial cell necrosis also occurred after bleomycin injection or hyperoxia. Maximal concentrations of hydroxyproline occurred in mice showing respiratory distress after six days of hyperoxia. Concentrations returned to zero during the subsequent phases of cell regeneration and fibrosis seen after bleomycin injection and irradiation. There was little change in the cellular components of bronchoalveolar lavage fluid at any time. The results indicate that collagen breakdown occurs during acute lung injury and can be quantified in terms of the hydroxyproline concentration in lavage fluid. Such a change in the extracellular matrix might influence the subsequent division and differentiation of regenerating cells during repair.

Metabolic iteration, evolution and cognition in cellular proliferation

A model for cellular proliferation is described according to which proliferation ensues when metabolism evolves towards commitment to DNA synthesis, and inhibition of proliferation occurs when enzymic interactions are iterated within a few metabolic pathways, another limiting factor being the supply of metabolites. The model successfully describes cellular growth and division as a 'cognitive process' based on interaction within enzymic elements and the genome, and affords an explanation in these terms of some empirical phenomena which have previously been understood only as isolated observations.

Response of mouse lung to crocidolite asbestos. 1. Minimal fibrotic reaction to short fibres

To determine the relationship between the development of pulmonary fibrosis and the size of deposited asbestos, we prepared a pure sample of short crocidolite fibres and instilled 0.5 mg of 0.1 mg to the lungs of mice. Animals were killed up to 20 weeks later with 3H thymidine injected 1 h before death. By bronchoalveolar lavage, there was a rapid transient increase in polymorph neutrophils (PMN) and in glucosaminidase levels; alveolar macrophage (AM) numbers were elevated in the 0.5 mg group for eight weeks. Most fibres were phagocytized by AM, many of which were heavily laden and cleared from the lung over the 20 week period. Some fibres were seen in type 1 epithelial cells, frequently associated with cell injury. From cell kinetic studies, a very brief proliferative response was seen in bronchiolar epithelial and Type 2 alveolar epithelial cells. A greater response was seen in interstitial fibroblasts which showed increased labelling up to two weeks after 0.5 mg asbestos. However no granulomas were seen and very little fibrosis was found by morphology or by biochemistry at any time after 0.5 mg; no fibrosis was seen after instilling 0.1 mg. The results show that a high dose of exclusively short asbestos fibres produces minimal lung injury and fibrosis in spite of long standing macrophage-fibre interaction in the alveoli.

Glycosidases in normal and regenerating chicken liver, hepatoma Mc-29, Rous sarcoma, in turkey poult liver and hemocytoblastomes, provoked by the leukosis virus strain Mc-31

Four glycosidases (beta-galactosidase, alpha-mannosidase, alpha-fucosidase and beta-N-acetylglucosaminidase) were studied in chicken normal and regenerating liver, in turkey poult liver and in virus induced avian tumors--chicken hepatoma (strain Mc-29), Rous sarcoma (strain Schmidt-Ruppin) and turkey poult hemocytoblastoma nodules (strain Mc-31). The multiple forms of beta-N-acetylglucosaminidase were assayed as well. A particular enzyme pattern was found in the tumor lines under investigation. A characteristic property of hepatoma cells was the elevation of beta-galactosidase activity and of the former enzyme and that of beta-N-acetylglucosaminidase for the hemocytoblastoma. In Rous sarcoma the glycosidase activities (except that of alpha-fucosidase) were much lower, compared to the other two solid tumors. All enzyme activities were compared with those in the normal liver of the corresponding avian species, and with the liver of tumor bearing fowls and with regenerating chicken liver. Unlike the rat liver in the avian normal and tumor tissues the percentual ratio between the multiple forms A and B of beta-N-acetylglucosaminidase was found to be 30:70%.

Significance of glycosidase patterns in lymphoid cells

Characteristic patterns of cell bound lysosomal glycosidases were found in different lymphoblastoid cell lines derived from Epstein-Barr virus-transformed lymphocytes. The enzyme pattern resembled that found in normal lymphocytes from healthy individuals except for a marked increase in alpha-L-fucosidase. beta-D-Glucuronidase on the contrary markedly decreased in the lymphoblastoid cells. Burkitt's lymphoma cells on the other hand showed glycosidase patterns that were quite distinct from those in lymphoblastoid cells. Each lymphoma cell line showed a characteristic pattern. This is one indication of a heterogeneous origin of these tumors. Glycosidase patterns may be used to roughly distinguish different lymphoid cell lines.

Contribution of alpha-D-galactopyranosyl end groups to attachment of highly and low metastatic murine fibrosarcoma cells to various substrates

There are much greater numbers of cell surface terminal, non-reducing alpha-D-galactorpyranosyl groups in highly malignant (metastatic) cells than are found in low malignant cells derived from the same murine fibrosarcoma. We have examined the contribution of these residues to attachment of the cells to various collagens and to plastic. Removal of these carbohydrate groups with alpha-galactosidase or blocking them with lectins from Griffonia simplicifolia seeds or with anti-blood group B antiserum all dramatically inhibited the attachment of both the highly malignant and the low malignant cells. Following removal with the enzyme, the alpha-D-galactopyranosyl end groups were rapidly resynthesized. This resynthesis was inhibited by tunicamycin, an inhibitor of de novo glycoprotein synthesis. This antibiotic also impaired cell attachment and, when used in addition to treatment with alpha-galactosidase, it inhibited cell attachment more than did treatment with the enzyme alone. The effects of all treatments on cell attachment were greater for the highly malignant than for the low malignant cells. With the latter cells, inhibition by lectin was seen only in the absence of serum, whereas the adhesion of highly malignant cells was affected in both the presence and the absence of serum. On their surface membrane the highly malignant cells express much more than do the low malignant cells of a glycoprotein that cross-reacts immunologically with laminin. The basement membrane glycoprotein laminin promotes cell attachment to collagen, and both glycoproteins contain terminal, non-reducing alpha-D-galactopyranosyl groups. Attachment of cells is a requirement for the formation of a metastasis, and thus the laminin-like molecule and the alpha-D-galactopyranosyl end groups (whether on the laminin-related moiety or on other cell surface molecules) may both be important for expression of the most malignant phenotype.

The histochemistry of glycosidases in human benign and malignant breast tissue

Histochemical methods for the localization of four glycosidases (beta-glucuronidase, beta-N-acetyl glucosaminidase, beta-D-galactosidase and alpha-mannosidase) have been applied to 40 cases of human normal and hyperplastic breast tissue and 100 human breast carcinomas. All tissues have been fixed in formol-calcium at 4 degrees C and washed in gum sucrose. beta-Glucuronidase and beta-N-acetyl glucosaminidase have consistently been detected in essentially all cells of normal and hyperplastic tissue. A similar distribution has been found for better differentiated carcinomas but the number of cells with detectable enzyme decreases in the more poorly differentiated tumour. beta-D-Galactosidase and alpha-mannosidase have only been demonstrated in very occasional cells in normal breast tissue. The incidence increases in hyperplastic tissue, and in approximately half the carcinomas many cells have detectable enzyme. The localization of beta-D-galactosidase has not been related to tumour differentiation but the better differentiated carcinomas tend to have few cells with demonstrable alpha-mannosidase. Although it has been suggested that glycosidases can have an effect on membrane function no differences have been found between those carcinomas having a few or many cells with detectable enzyme and the presence or absence of axillary lymph node metastasis. Total enzyme activity cannot be detected in fixed tissue, nor can an accurate quantitative assessment be made, but under the conditions of this study it is possible to conclude that there are differences between normal and malignant breast tissue in the localization of glycosidases.

Approach to the mechanism of Zajdela's hepatoma cell growth inhibition induced by concanavalin A and phytohaemagglutinin

Cell growth of tumour ascites cells was inhibited by concanavalin A, phytohaemagglutinin and Ricinus lectin at 2-100 micrograms/ml. As expected, the Ricinus lectin inhibited the protein synthesis estimated by leucine incorporation and decreased thymidine incorporation, whereas concanavalin A and phytohaemagglutinin stimulate the uptake and the incorporation of both leucine and thymidine, and thus, synthesis of protein and DNA. These results suggest that different mechanisms are involved in the hepatoma cell growth inhibition by the lectins. This difference was not related to the kinetic characteristics of the lectin interactions with the cells which represent a first and necessary step. It was showed that concanavalin A and phytohaemagglutinin as well as chloroquine inhibited the 14C-labelled asialofetuin degradation. We can conclude that Ricinus lectin present a toxic effect whereas both concanavalin A and phytohaemagglutinin show an anti-protease activity.

Changes in cellular glycoproteins after transformation: identification of specific glycoproteins and antigens in sodium dodecyl sulfate gels

The glycoproteins of whole cells have been analyzed by direct application of radio-iodinated lectins to sodium dodecyl sulfate gels, followed by autoradiography. By use of lectins with different carbohydrate specificities, different sets of glycoproteins have been visualized. The most prominent lectin-binding band in many gels is thelarge, external, transformation-sensitive (LETS) protein. Major glycoprotein differences are revealed when normal and virus-transformed cells are compared. Certain differences, however, are also seen when the glycoproteins are compared from two separately derived simian virus 40 transformants of 3T3 cells, suggesting a degree of clonal variation between these lines that may not relate to transformation. A complementary technique is used to detect specific antigens in sodium dodecyl sulfate gels by direct application of iodinated antibodies. An antiserum specific for the LETS protein is used to identify this antigen in the gels of both normal and transformed cells.

Lysosomal hydrolases of the epidermis. 6. Changes in disease

The activities of 14 acid hydrolases have been measured in normal and diseased human epidermis. Our findings were as follows: (i) Increased hydrolase activity was common in lesions; the clinically uninvolved skin of patients, however, invariably showed normal values. (2) The pattern of change was independent of the nature of the didease, the arylsulphatases and beta-glucosidase usually showing the greatest elevations. (3) The magnitude of the changes differed from disease to disease, being most marked in the lesions of psoriasis. (4) Ichthyosiform erythroderma was exceptional in showing elevated levels of the galactosidases and cathepsins B1 and D. We suggest that (with the exception of ichthyosiform erythroderma) the abnormalities which we have observed may be related to the proliferative rate of the epidermis.

The demonstration of acid phosphatase in cultured 3T3 mouse cells

Acid phosphatase has been demonstrated ultrastructurally in 3T3 and SV40-3T3 mouse cells using sodium beta-glycerophosphate and p-nitrophenyl phosphate as substrate. The former substrate only demonstrates the enzyme in lysosomes and elements of the Golgi apparatus while the latter demonstrates it in the cisternae of the endoplasmic reticulum and in the cell surface as well as at lysosomal sites. The significance of surface acid phosphatase activity is discussed in terms of sublethal autolysis.

[Disturbed distribution of surface glycoconjugates of the plasma cell membrane in psoriasis. Cytochemical detection using the alcianblue-lanthan-reaction (author's transl)]

Lanthanum has been used as a tracer for the intercellular space and the surface coats in different epithelia including human epidermis, however, lanthanum compounds may or may not penetrate into skin specimes and reaction product may or may not be present in the intercellular space. After treatment with alcian blue prior exposure to lanthanum the trilaminar plasma membrane was more regularly stained and a thin coat of reaction product corresponding to superficial glycoconjugates outlined the cell surface and filled the narrow intercellular space in normal epidermis. In psoriatic epidermis the quantity of superficial membrane-bound glycoconjugates was rather reduced, their distribution and compartmentalization was profoundly changed and the outer leaflet of the trilaminar plasma membrane was not always clearly seen, having a "moth-eaten appearance" in some places. These findings show once more that alterations of the cell membranes and their surface architecture are present in psoriasis. They may play a major role in the pathogenesis of the disease, influencing the activities of membrane-bound enzymes and the flow of the epidermal growth control mechanism. The glycocalyx may serve in this mechanism as an accumulator of energy rich compounds or as a receptor site of membrane-bound ezymes. According to our views it represents a "ground substance" of epidermal origin, which controls the social behaviour of the keratinocytes in tissue.

Interaction of concanavalin A with the surface of virus-infected cells

Infection of untransformed cells with a wide-range of non-oncogenic enveloped viruses causes a significant increase in their susceptibility to agglutination by concanavalin A (Con A). The increased Con A agglutinability of these cells is not caused by an increase in the number of Con A sites on the cell surface but involves alteration in the surface properties of infected cells to allow redistribution of Con A receptors to form "patches" following binding of Con A to the cell surface. Similarities between Con A-mediated agglutination of normal cells infected with non-oncogenic viruses and the agglutination response to cells transformed by oncogenic viruses will be reviewed. Finally, the use of Con A as an experimental tool to modify the replication and cytopathogenicity of non-oncogenic viruses grown in mammalian cells will be presented.