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E Moczar

Publications and source records attributed to E Moczar.

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Effects of glycosaminoglycans and extracellular matrix components on metastatic rat rhabdomyosarcoma tumor and myoblast cell proliferation.

Experiments were performed to determine the relative effects of glycosaminoglycans and extracellular matrix components alone or in association with various substrates, including extracellular matrix, on the proliferation of rat rhabdomyosarcoma (RMS) cell lines of different metastatic potential and nontumorigenic rat myoblast L6 cells. The assays used various substrates: tissue culture plastic, type I and IV collagen, fibronectin, laminin and extracellular matrix deposited by corneal endothelial cells. In control experiments, tumor cells grew faster on fibronectin and extracellular matrix than on the other substrates, and their proliferation rate was decreased slightly by laminin. Collagens were growth-inhibitory only for the highly metastatic line. The proliferation rate of L6 myoblasts was not greatly affected by the different substrates. The addition of exogenous glycosaminoglycans to the culture medium modified cell proliferation on the various substrates. Heparin inhibited the growth of all the cell lines tested, independent of the substrate. When cultured on laminin substrate the proliferation rates of the cell lines were depressed by addition of heparan sulfate to the medium, and this effect was more pronounced in the metastatic RMS lines. Chondroitin sulfate and dermatan sulfate enhanced the growth rates of the tumorigenic cells when cultured on collagen type I surfaces. Hydrocortisone, which induces myogenic differentiation, decreased the cell proliferation rates of all the cell lines tested and intensified the inhibitory effects of heparin when added simultaneously to the culture medium. The results showed that glycosaminoglycans and other matrix components can affect the proliferation rates of rhabdomyosarcoma cell lines.

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Hyaluronate-binding proteins in weakly and highly metastatic variants of rat rhabdomyosarcoma cells.

Weakly (RMS8) and highly (RMS0) metastatic rat rhabdomyosarcoma cells were assayed for their interaction with hyaluronate. The cells in subconfluent cultures were incubated with 35S methionine, the cells were fractionated and the labelled proteins were separated by affinity chromatography on hyaluronate-Sepharose and by HPLC. The RMS8 cells expressed about twice the amount of labelled hyaluronate-binding proteins seen in the RMS0 cells. The molecular sizes of the main hyaluronate-binding proteins were similar in both cell types. Unlike the RMS0 cells, the RMS8 cells took up exogenous, radioactively labelled hyaluronate at 4 degrees C in a saturable and specific way with high affinity. Cells were also incubated with 3H glucosamine. The isolation of the glycosaminoglycans from these cultures by ion-exchange chromatography indicated that the RMS8 cells retained more endogenous 3H hyaluronate in their pericellular domain than did the RMS0 cells. The attachment of trypsinized cells could be inhibited with exogenous hyaluronate, indicating that the proteins with affinity for hyaluronate may act as hyaluronate-binding sites on these cells.

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PubMedDate not supplied

Modulation of proteoglycan metabolism by hydrocortisone and by growth factors in rhabdomyosarcoma cell lines of different metastatic potentials.

Glycosaminoglycans of cultured nickel-induced rat rhabdomyosarcoma cell lines with different metastatic potentials, grown in the presence or in the absence of hydrocortisone and of growth factor (EDF and EDGF) were investigated comparatively. The newly formed [35S]sulphate and [3H]glucosamine-labelled glycosaminoglycans were analysed in the extra-, peri- and intra-cellular compartments of the following cell lines: the strongly metastatic and colonizing 9-4/0 parental line, the very weakly metastatic and weakly colonizing subline 8 and the very weakly metastatic but colonizing subline 13a2. The cell surface of the weakly metastatic 8 and 13a2 lines was richer at least 5 and 2 times respectively in sulphated glycosaminoglycan label than the surface of the strongly metastatic 9-4/0 parental line. Hydrocortisone provoked an approximately four-fold increase in the label of the sulphated cell surface glycosaminoglycans of the 9-4/0 line. The pattern of the labelled cell surface glycosaminoglycans of these cells become similar to that of cells from the very weakly invading subline 8. Hydrocortisone induced only minor changes in the distribution of the glycosaminoglycans in the 8 and 13a2 lines, and at the same time, their proliferation rate and differentiation state was only slightly affected by this drug. Conversely to hydrocortisone, EGF increases the proliferation of the 9-4/0 line and also increases the label in sulphated cell surface glycosaminoglycans. This increase is about 50 per cent of that obtained by hydrocortisone. Thus, the accumulation of the glycosaminoglycan label on the cell surface is not directly related to the cell growth in the case of these cells. The results suggest that sulphated cell surface glycosaminoglycans, especially chondroitin sulphate, are involved in the inhibition of metastasis formation of the rhabdomyosarcoma cell lines studied.

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PubMedDate not supplied

Comparative study on Lewis lung tumour lines with 'low' and 'high' metastatic capacity. III. Glycosaminoglycan synthesis, transport and degradation in cell lines.

The glycosaminoglycans (GAGs) of low (LM) and highly metastatic (HM) cell lines of the Lewis lung tumour (3LL) were compared using [3H]glucosamine labelling techniques. The GAGs isolated from nuclei, cytoplasm, pericellular fractions and medium were analysed by cellulose acetate electrophoresis and by digestion with specific enzymes, and the following conclusions were drawn. 1. Increased cellular uptake and incorporation of [3H]glucosamine into glycoconjugates of the cytoplasm was a typical feature of the highly metastatic cell line after a 48-h labelling. However, there was no elevated radioactivity in glycolipids. 2. Radioactivity of the purified GAGs was two and three times higher in nuclear and cytoplasmic fractions of HM cells than in those of LM cells. There was much less difference between the two cell lines in the pericellular fractions. 3. A definite change from chondroitin sulphate to dermatan sulphate dominancy was recorded in each GAG fraction. Higher heparan sulphate labelling was observed in the cytoplasmic and pericellular GAGs of HM cultures. 4. In the post-labelling period about three times more GAG was present in the extracellular compartment of the HM cultures compared with the LM cultures. 5. In the LM cultures the total GAG-associated radioactivity decreased by 73 per cent in the 48-h chase period whereas in the HM cultures it decreased by only 30 per cent. This indicates a higher rate of GAG degradation in the LM cultures.

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