Homotypic cell-cell adhesion molecules and tumor invasion.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
M Mareel
Publications and source records attributed to M Mareel.
E-cadherin expression: a counterbalance for cancer cell invasion.
Invasion, eventually leading to metastasis, is presented as the result of a balance between the activation of 2 sets of genes, coined i+ (invasion promotor) and i- (invasion suppressor) genes. Experiments in vitro have indicated that the homotypic homophilic epithelial cell--cell adhesion molecule E-cadherin (L-CAM; uvomorulin; cell CAM 120/80; Arc-1; rrl antigen) is an i- gene product. In several cell families, manipulation of E-cadherin at the level of the protein by antibody-mediated inactivation, at the level of the mRNA by antisense DNA transfection, and at the level of the genome by sense DNA transfection respectively resulted in induction and suppression of invasiveness. Nude mouse tumors from non-invasive homogeneously E-cadherin-positive cell populations were found to be invasive and metastatic. These tumors expressed E-cadherin in a heterogeneous manner, the undifferentiated cells being negative; but tumor-derived cells in culture were again E-cadherin-positive, indicating downregulation of this protein by host factors. Several types of human cancers showed a similar heterogeneity suggesting a relationship between downregulation of E-cadherin and invasion. Our current research focus is on the factors responsible for E-cadherin downregulation in experimental and human cancers.
Animals↗
Interleukin-1 is a motility factor for human breast carcinoma cells in vitro: additive effect with interleukin-6.
Interleukin-1 beta (Il-1 beta) and interleukin-1 alpha (Il-1 alpha) were shown to act as motility factors for the human breast carcinoma cell lines SK-BR-3 and ZR-75-1 in vitro. Both cytokines induced transition from the stationary to the motile phenotype (spreading). Il-1 beta stimulated translocation, shape change and random migration (chemokinesis) of SK-BR-3 cells as demonstrated by time-lapse video recordings and by a modified Boyden chamber assay. Interleukin-6 (Il-6) stimulated spreading of the SK-BR-3 cells; an additive effect with Il-1 beta on spreading and fast plasma membrane movements was evidenced. In the SK-BR-3 cell line, the signal transduction of Il-1 beta and Il-6 differed, since only the effect of Il-6 on spreading was sensitive to pertussis toxin. Both Il-1 beta and Il-6 required protein synthesis to stimulate spreading, since cycloheximide inhibited the effect of the cytokines. Induction of an autocrine loop of Il-6 in the SK-BR-3 cells by Il-1 beta was unlikely, since after stimulation with Il-1 beta, no induction of Il-6 activity was measured, nor was inhibition of stimulated spreading seen in the presence of an antiserum against Il-6. Addition of Il-8 or of an antiserum against Il-8 did not affect spreading. We concluded that Il-1 and Il-6 could act as motility factors for human breast carcinoma cells, in both an independent and an additive way.(ABSTRACT TRUNCATED AT 250 WORDS)
Breast Neoplasms↗
Methods of study of the invasion of malignant C3H-mouse fibroblasts into embryonic chick heart in vitro.
Methods of study of tumour invasiveness in vitro were investigated using the interactions between malignant virally transformed C3H mouse fibroblasts (MO4) with fragments from embryonic chick heart. Invasion of MO4 cells into the heart tissue could be demonstrated in all three-dimensional cultures. On the contrary, seeding of MO4 cells on top of a monolayer of heart cells did not mimic invasion. Precultured heart fragments were more suitable for the study of the early phase of invasion than freshly cut ones because they presented healthy well-delineated borders. Aggregates of MO4 cells proved more suitable than suspensions or monolayer fragments because they were amenable to quantitation, were not traumatized or treated with enzymes during harvest. They allowed precise control of the initial site of contact with the heart tissue. The nature of the culture medium predominantly affected the growth of the MO4 population. This factor influenced the pattern of invasion quantitatively, but did not alter the invasive capacity of the MO4 cells itself. In cultures on adhesive substrates the interaction between the MO4 cells and the heart tissue was complicated by the fact that both also interacted with the aritficial substrate. Shaker cultures appeared better than comparable static cultures because they allowed better aeration and so delayed central necrosis.
Animals↗
Invasion of malignant C3H mouse fibroblasts from aggregates transplanted into the auricles of syngenic mice.
Spheroid aggregates of malignant fibroblasts (MO4), shown to be invasive in vitro, were implanted subcutaneously into the auricle of the external ear of syngenic C3H mice. The course of early invasion into the surrounding tissues and the formation of tumours was studied in serial sections of auricles fixed 6 h to 30 days after implantation. MO4 cells are first observed to make contact with the surrounding tissues after 6 h. They exhibit, cytoplasmic extensions and spread from the original aggregate. During the first day invading MO4 cells preferentially follow tissue crevices created by the inoculation procedure. Later they also invade the surrounding tissues. Polymorphonuclear leucocytes, and later monocytes infiltrate the aggregate, which is completely destroyed after 4 days. Palpable tumours arise from MO4 cells that have left the original implant and invaded the tissues of the auricles. These observations indicate that invasion of malignant cells is important for the take of a transplant.
Animals↗
Heparan sulfate at the surface of HeLa cells.
HeLa cells, labeled with Na235SO4, release into the culture medium 35SO4 bound to plasma membrane vesicles next to 35SO4-glycoproteins and free 35SO4. Plasma membrane vesicles, experimentally produced by treatment with formaldehyde, contain 35SO4 and their surface can be stained with high iron diamine. Scanning of chromatograms of the trypsinate from labeled cells demonstrates radioactivity on the spot of heparan sulfate. It is concluded that HeLa cells synthesize heparan sulfate, which is incorporated at the plasma membrane and released by shedding of small vesicles.
Cell Membrane↗
Comparative studies of two types of "spontaneous" malignant alteration of ST/A mouse lung fibroblasts propagated in vitro.
Two types of apparently spontaneous malignant alterations of fibroblastlike ST/a mouse lung cells (ST-L cells) grown in vitro are described. One type is characterized by a high tumorigenic potential of the altered cells in nonconditioned syngeneic recipients, a fibroblastlike morphology with cell surface showing very few microvilli by scanning electron-microscopy (SEM), and a growth pattern typical of nontransformed cells. These cells were described as R- cells. The other type is characterized bya low tumorigenic potential in non-conditioned, immunocompetent syngeneic recipients, rounding up of the cells which by SEM showed numerous microvilli on the surface, and a growth pattern typical of transformed cells. These cells were described as round cells or R+ cells. In immunoincompetent mice, R+ cells readily produced sarcomas, which grew faster than those produced by R- cells. Both types of ST-L cells expressed murine leukemia virus (MuLV) when tested in a peroxidase anti-p30 plaque test. The concentration of murine leukemia virus envelope glycoprotein (gp70) has previously (5) been shown to be threefold higher in R+ cells compared to R- cells. Furthermore, round-cell transformation was accompanied by the development of crossreacting rejection antigens protective against a secondary shallenge with Ehrlich ascites tumor and with syngeneic dimethylbenzanthracene induced ST/a mouse leukemia (STABAL). A similar protection was obtained by preimmunization with a cloned embryonic feral mouse cell line (SC-1) infected with ST-L virus as well as with virus-free SC-1 cells, suggesting the presence of rejection antigens both of viral (gp70) and nonviral origin.
Animals↗
Morphology and 125I-concentration of embryonic chick thyroids cultured in an atmosphere of oxygen.
In vitro culture of whole thyroid glands may lead to loss of differentiation and function. Comparison by histology, histoautoradiography and gammacounting of 125I-concentration, of 12 to 13 days old embryonic chick thyroids, cultured on a gyratory shaker either in an atmosphere of 5% CO2 and air or of 95% O2 and 5% CO2, shows that a high concentration of O2 maintains the morphological and functional integrity of the thyroids for at least 4 days.
Animals↗
Methyl (5-(2-thienylcarbonyl)-1H-benzimidazole-2-yl) carbamate, (R17934), a synthetic microtubule inhibitor, prevents malignant invasion in vitro.
The effect of malignant invasion of methyl (5-(2-thienylcarbonyl)-1H-benzimidazole-2-yl) carbamate, (R17934), a microtubule inhibitor, was examined in organotypical co-cultures of mouse sarcoma virus transformed cells (MO4) and embryonic chick tissues. In contrast with control cultures, 1 microgram/ml R17934 prevented invasion of MO4 cells into the host tissue. Since mitostatic doses of 5-fluorouracil did not inhibit invasion, we presumed that the anti-invasive properties of R17934 were correlated with a loss of microtubule mediated directional cell migration.
Antineoplastic Agents↗
Colloidal iron binding to the surface of HeLa cells, spreading in monolayer culture.
We have used the colloidal iron (CI) binding technique, adapted for transmission electron microscopy, for semiquantitative evaluation of the negative charge density at the surface of HeLa cells in monolayer culture. The surface area increases when HeLa cells spread on the substrate. This increase brings about a decrease in the thickness of the CI rim, indicating a decrease in negative surface charge density. This phenomenon implicates lowering of the electrostatic repulsion, and explains the formation of intercellular contacts at the level of spread parts of the cell. Because of lack of penetration, CI particles are absent in regions of cose apposition between cells and between cells and substrates. Absence of CI binding in broader intercellular or cell-substrate spaces was explained through masking of the anionic groups.
Cell Membrane↗
Invasion of malignant cells into 51Cr-labeled host tissues in organotypical culture.
We have attempted to quantitate malignant invasion in vitro. Therefore we adapted the 51Cr-release cytotoxicity test to organotypical culture systems, that proved useful for morphological analysis of invasion. We counted 51Cr-release from labeled fragments of embryonic chick heart and mesonephros, cultured either on semi-solid or in fluid medium, during their invasion by HeLa cells. Although demonstrated morphologically, malignant invasion did not bring about significant changes of 51Cr-release as compared to control cultures without HeLa cells. The failure of the 51Cr-release test in our experimental device might shed some light on the mechanisms of malignant invasion.
Animals↗
Invasion of malignant cells into cultured embryonic substrates.
To study malignant invasion, we associated tissue and cell culture fragments, with adhesive and non-adhesive living substrates in vitro (11). Non malignant mesonephros, quail heart and BHK-cells, as well as malignant HeLa-, Hepatoma-, Harding-Passey melanoma-, Py-, TLX5 lymphoma- and Schmidt-Ruppin sarcoma cells, were transplanted into cultured organ fragments of chick embryos and chick blastoderms. Malignant invasion was evaluated on the basis of the following histological criteria: 1. changes in organization of the graft. 2. infiltration of cells from the graft into the substrate, 3. degenerative alterations of the substrate. It was shown that adhesion of the graft to the substrate is a prerequisite for malignant invasion. Invasion into non-adhesive substrates, such as the apical side of epithelia, was never observed. Contrary, all malignant cells did invade into adhesive substrates. Interposition of a vitelline membrane always inhibited the expression of invasiveness. The morphological pattern of invasion depended mainly on the architecture of the substrate and differential resistance of its various components explained well all histological pictures. From the latter observation and from the localization of degenerative changes in the substrate we inferred that malignant cells exert their deleterious effect most probably upon immediate contact with their host.
Animals↗
Histochemical evidence for sulfomucins at the surface of Hela cells.
The nature of the negatively charged groups present at the surface of HeLa cells was further investigated. Therefore we applied a series of light microscopic staining techniques, widely used for the demonstration of epithelial mucosubstances on tissue sections, to HeLa cells from suspension cultures. Our histochemical findings confirmed the presence of carboxylated substances at the surface of these cells. Furthermore we obtained conclusive evidence for the presence of sulfated molecules. Both substances seem to be closely related to epithelial sialomucins and sulfomucins.
Alcian Blue↗
Cytochemistry of colloidal iron binding to the surface of Hela cells and human erythrocytes.
It seems from the literature that colloidal iron (C.I.) binding sites on cell surfaces cannot be completely removed by treatment with Vibrio Colerae alpha-neuraminidase. We wondered if C.I. particles bind to negative groups other than the carboxyl groups of sialic acids. Using HeLa cells from suspension cultures and fresh human erythrocytes, we examined, with the transmission electronmicroscope, the influence of the following enzymatic and histochemical treatments on C.I. staining: alpha-neuraminidase; hyaluronidase; ribonuclease; alpha-amylase; mild methylation (MM); MM + saponification (Sap.); MM + Sap +MM; MM + Sap + alpha-neuraminidase; active methylation (AM); AM + Sap; AM + Sap + AM; AM + Sap + alpha-neuraminiadase; CH3OH (80%); Sap. It seemed from these experiments that the carboxyl groups of alpha-neuraminidase sensitive sialic acids constitute the majority of binding sites for C.I. to these particular cells. The most interesting candidates for the residual binding of C.I. are carboxyl groups of alpha-neuraminidase resistant molecules, sulfon, sulfin, and sulfate groups.
Binding Sites↗
Characterization of spontaneous, chemicak, and viral transformants of a C3H/3T3-type mouse cell line by transplantation into young chick blastoderms.
Cells from a C3H/3T3-type cell line were transplanted into defects of the lower layer of stage-4 chick blastoderms before and after "spontaneous," chemical, and viral transformation. To check the validity of inhibition of lower-layer defect closure as a criterion of malignancy, we compared the behavior of the lower layer toward these cells with their in vitro growth pattern, their capacity to invade embryonic chick skin explants that were organotypicaly cultured, and their tumorigenicity in syngeneic mice. No false-positive results were observed with either test. The study of the in vitro growth pattern gave false-negative results during the early phase of spontaneous transformation, whereas these cells, exhibiting an untransformed growth pattern, were shown to be malignant by the other tests. We concluded that the inhibition of lower-layer defect closure is a reliable, sensitive and rapid test for the detection of malignancy in tissue-cultured cells from any source.
Animals↗
Adhesion of malignant and nonmalignant cells to cultured embryonic substrates.
To study adhesion, which is probably the initial step in malignant invasion, we associated tissue culture fragments with living substrates in vitro. Malignant HeLa, hepatoma, and PY cells, as well as nonmalignant BHK cells, were transplanted into cultured chick blastoderms and organ fragments from chick embryos. Adhesion was evaluated by time-lapse cinematography, by flushing with Tyrode's solution, and by histological examination after fixation. It was shown that the adhesion of these tissue culture fragments depends on the nature of the substrate. Substrates of connective tissue, mesenchyme, and the basal side of epithelia proved to be adhesive. In contrast, the apical side of intact epithelia was nonadhesive. Perforated epithelia allowed adhesion at the site of the perforation. In the presence of dilysine, HeLa cells adhere to the apical side of epithelia and to the dorsal side of the upper layer of the blastoderm. We concluded that the apical side of intact epithelia constitutes an inappropriate substrate for adhesion of a large variety of cells, in vitro as well as in vivo. Alteration of this characteristic in the presence of dilysine indicates that long-range electrostatic repulsion might be responsible for the nonadhesive character of the epithelia.
Animals↗