PubMed Health⌕ Search

Biomedical subjects

K H Robért

Publications and source records attributed to K H Robért.

8 recordsLinked to original sources
PubMed1993

Chemotaxis and haptotaxis of human malignant mesothelioma cells: effects of fibronectin, laminin, type IV collagen, and an autocrine motility factor-like substance.

A human malignant pleural mesothelioma cell line (STAV) was studied with respect to production of the extracellular matrix components laminin, type IV collagen, and fibronectin, and interactions with these proteins in vitro. We also analyzed STAV cell serum-free conditioned medium with respect to the possible presence of "autocrine motility factor-like" substance. Sodium dodecylsulfate-polyacrylamide gel electrophoresis of biosynthetically labeled STAV serum-free conditioned medium showed that STAV cells released several proteins into the medium, including components with molecular weights of 850,000, 540,000 and 440,000. Using Western blotting we identified these proteins as laminin, type IV collagen, and fibronectin, respectively. By immunocytochemistry laminin, type IV collagen, and fibronectin were detected as a matrix surrounding the cells. Plastic culture dishes coated with microgram quantities of laminin, type IV collagen, and fibronectin induced attachment and spreading of STAV cells. Laminin, type IV collagen, and fibronectin stimulated directional (chemotactic) migration of STAV cells in Boyden chambers fitted with 8 microns filters. The same cells also migrated to insoluble step gradients of filter-bound extracellular matrix components (haptotaxis). When STAV serum-free conditioned medium was separated by using fast protein liquid chromatography Superose 6 gel filtration, two motility-inducing protein peaks were detected. The first peak contained proteins with molecular weight > 220,000 that had both chemotactic and haptotactic properties, while the second peak contained material with apparent molecular weights of approximately 67,000 that had chemotactic and chemokinetic (random motility) but not haptotactic properties. Analysis of the M(r) 67,000 material indicated that it was a heat-sensitive and trypsin-digestible protein. The production of both soluble and insoluble extracellular matrix components by human mesothelioma cells and the motile response to these molecules as well as the production of a M(r) 67,000 autocrine motility factor-like substance may be important for the highly invasive motile behavior of this tumor.

Cell Adhesion↗
PubMed1991

Nucleokinesis: distinct pattern of cell translocation in response to an autocrine motility factor-like substance or fibronectin.

Human lung adenocarcinoma cells develop bipolar shape with prominent pseudopodia (greater than or equal to 200 microns) when cultured in the presence of autocrine motility factor (AMF)-like substance or on fibronectin-coated substrata. AMF was partially purified from a human lung adenocarcinoma cell line and has a peak biological activity at a molecular mass of 67 kDa. Using time-lapse photography, we observed that during AMF- or fibronectin-induced cell translocation, the nuclei of some bipolar cells are transported to the opposite end of the cell, while gross cell shape and position remain unchanged. Following this nuclear movement, which we call "nucleokinesis," the posterior pseudopodium is retracted behind the nucleus. Thus, extension of a pseudopodium followed by nucleokinesis in the same direction and retraction of the cell body behind the nucleus is a normal motile sequence in translocating bipolar cells. This suggests that nucleokinesis is a distinct step in whole-cell translocation of bipolar cells on biological substrata and that pseudopodia can be used as nuclear transport organs. In contrast, adenocarcinoma cells cultured on artificial substrata and in the absence of AMF display a fibroblast-like motility pattern with the nucleus centrally located within the migrating cell.

Adenocarcinoma↗
PubMed1989

Serum-dependent growth patterns of two, newly established human mesothelioma cell lines.

Two cell lines with different in vitro growth patterns were established from the pleural fluid of a patient with malignant epithelial pleural mesothelioma. The cell line established in RPMI 1640 supplemented with human AB serum had an epithelial morphology, while the cell line established in fetal calf serum-supplemented medium had a fibroblast-like morphology. Exposure of the fibroblast-like cell line to human AB serum-containing medium resulted in a nearly complete transformation of the morphology to the epithelial-like phenotype, and the epithelial-like cell line changed its phenotype to fibroblast-like upon exposure to fetal calf serum-supplemented medium. Both cell lines formed colonies in soft agarose and secreted hyaluronic acid into the culture medium. In both cell lines all the metaphases studied lacked chromosomes 5 and 9, demonstrating the same clonal origin. However, one marker and a missing chromosome 11 were found only in the fibroblast-like cell line. We conclude that human AB serum supplement can be used for the establishment of human tumor cell lines, and that the choice of serum can affect the in vitro morphology of the established mesothelioma cell lines. The mechanisms behind the different growth patterns seem to be a selective stimulation of different subpopulations of malignant cells as well as induction of changes in the morphology of individual cells.

Biomarkers, Tumor↗
PubMed1988

Clonal analysis of the response of HL-60 cells to retinoic acid and vitamin D in the presence or absence of leukocyte-conditioned medium.

The capacity of retinoic acid (RA) and vitamin D to induce differentiation of HL-60 cells in an agar gel system that permits a high cloning efficiency was studied in the presence or absence of leukocyte-conditioned medium (LCM). Vitamin D was about 10 times more effective in inducing differentiation than RA. LCM significantly increased the differentiation-inductive capacity of both vitamins, although LCM did not have an effect of its own. During the first days of culture, the number of cells per clone increased with either vitamin or LCM alone as compared to control cultures. This suggests that cellular proliferation may be important in the initial phase of the differentiation induction. No synergy in this respect was found between RA and vitamin D in the presence or absence of LCM. Thus it is doubtful whether RA and vitamin D have a true synergistic effect on individual HL-60 cell differentiation as previously described in liquid cultures. Furthermore, the findings suggest that the process of differentiation induction regarding the growing cells in agar gel involves an all-or-none process. The data may also help elucide the observed relationship between the in vitro production of colony stimulating activity and favorable prognosis of AML.

Cell Differentiation↗
PubMedDate not supplied

Interferon induces proliferation in leukemic and normal B-cell subsets.

3H-thymidine incorporation following stimulation with interferon (IFN) in vitro was investigated in cell cultures from peripheral blood of patients with chronic lymphocytic leukemia (CLL), spleens from necro-kidney transplants and healthy blood donors. It was demonstrated, that IFN can induce a proliferative response in some normal as well as leukemic B lymphocyte subsets. The responses were not T-cell dependent. The results indicate, that B-cell subsets that proliferate in the presence of IFN, are present in higher proportions in spleen than in peripheral blood, and that they constitute a portion of the leukemic blood lymphocyte pool in some patients with CLL. We have previously demonstrated, that IFN induces varying degrees of transformation and differentiation in blood lymphocytes from a majority of CLL patients. The functional characteristics of different B-cell subsets, and their heterogeneous distribution in leukemia, may be important for the results of IFN treatment in various malignant B-cell disorders.

B-Lymphocytes↗
PubMedDate not supplied

Production of a motility factor by a newly established lung adenocarcinoma cell line.

We have established and characterised a cell line, designated WART, from a patient with primary adenocarcinoma of the lung. This cell line grows with a doubling time of approximately 15 hours, forms colonies in soft agarose, is tumorigenic in athymic nude mice, and has a complex karyotype with both structural and numerical abnormalities. WART serum free conditioned medium (SFCM) contains a factor which stimulates motile behavior of WART cells. This factor with an apparent molecular weight of 67 kDa induced in an autocrine fashion prominent pseudopodia, and chemotactic and chemokinetic responses. Heparin affinity chromatography, ion exchange and molecular sieve chromatography accompanied by SDS-PAGE analysis showed that the motility inducing activity was associated with a major band with molecular weight 67 kDa. The motility inducing activity of the 67 kDa protein was not sensitive to reduction with either dithiotreitol or mercaptoethanol which distinguishes it from A-2058 melanoma autocrine motility factor (AMF)/autotaxin, HT-1080 fibrosarcoma AMF and scatter factor which lose their biological activity upon reduction. This 67 kDa motility inducing factor did not augment DNA synthesis indicating that its locomotor activity is independent of mechanisms regulating cell growth. Pertusis toxin inhibited the motile response induced by the 67 kDa protein indicating a signal transduction pathway involving G proteins. Due to its production of the motility stimulating protein the cell line could facilitate studies of invasion and metastasis of human lung tumors.

Adenocarcinoma↗
PubMedDate not supplied

A tumor derived motility factor that stimulates cell migration on extracellular matrix.

A factor that stimulates migration of lung carcinoma cells on biological substrata was purified from the human lung adenocarcinoma cell line WART. A partially purified autocrine motility factor-like substance, termed haptotaxin, was added to the lower compartment of Boyden chambers and the filters were coated on the upper, lower or both sides with different concentrations of the extracellular matrix (ECM) components fibronectin, laminin or collagen type IV. These adhesive proteins coated on the lower surface of the filter promoted the migration (haptotaxis) of lung carcinoma cells. This effect was greatly enhanced by the addition of haptotaxin. In contrast, ECM components (including gelatin) coated on the upper surface or on both filter surfaces did not stimulate tumor cell migration. However, the addition of haptotaxin also timulated cell migration under these conditions. Haptotaxin did not stimulate migration on filters coated with bovine serum albumin or on uncoated filters. Haptotaxin could not be absorbed by fibronectin, laminin, collagen type IV or gelatin, and soluble ECM components did not affect the locomotor effect of haptotaxin. Substrata coated with fibronectin, laminin and collagen type IV induced adhesion and spreading of lung carcinoma cells in a dose dependent fashion. Haptotaxin potentiated adhesion and spreading of tumor cells on these substrata but did not in itself mediate adhesion and spreading of the cells. Anti-VLA 2 antibodies inhibited migration to haptotaxin on gelatin and laminin coated filters but did not affect haptotaxin-induced migration on fibronectin or collagen type IV substrata. Anti-VLA-5 monoclonal antibodies inhibited haptotaxin-induced migration on fibronectin coated filters but not such migration on filters coated with other ECM molecules showing that tumor cells must interact specifically with ECM components in order to migrate to haptotaxin.

Adenocarcinoma↗