Laminin and 67 kD laminin binding protein in mouse B16 melanoma cells and 3T3 fibroblast spheroids.

Multicellular spheroids which promote cell-cell and cell-matrix interactions were prepared in culture with mouse B16 melanoma cells (pigmented or non pigmented) alone or mixed with mouse 3T3 fibroblasts. Their volume and proliferation or necrosis rate were evaluated. As measured by dot blot immunoassay, laminin was mainly produced by fibroblasts rather than by melanoma cells.

Tumor cell surface-associated binding site for the M(r) 72,000 type IV collagenase.

We have studied the capacity of two human breast adenocarcinoma cells, MDA-MB231 and MCF-7, to bind exogenous M(r) 72,000 type IV collagenase by both morphological and radioreceptor binding assays. By indirect immunofluorescence, staining with a specific anti-M(r) 72,000 type IV collagenase antibody was strongly induced when cells were preincubated with the purified enzyme. Scatchard plot analysis indicated the existence of a binding site for the M(r) 72,000 type IV collagenase with high affinity for both cell lines (Kd = 2 x 10(-9) M).

Acyclovir vs isoprinosine (immunovir) for suppression of recurrent genital herpes simplex infection.

Objective: To compare the efficacy and safety of oral acyclovir (400 mg twice daily) with oral isoprinosine (500 mg twice daily) in the suppression of recurrent genital herpes.

Design: Double-blind, double-dummy, randomised, controlled, parallel group trial.

Setting: 13 centres in UK, Belgium and Germany.

Galactose alpha 1-3 galactose and anti-alpha galactose antibody in normal and pathological pregnancies.

The galactose alpha 1-3 galactose (Gal alpha 1-3 Gal) residue is a carbohydrate widely distributed in many non-human mammals. Since Gal alpha 1-3 Gal residues are described on the cell surface of tumor cells, we have examined the possibility of their expression on human trophoblastic cells at different stages of placental implantation and in various pregnancy-associated conditions. Using immunohistochemical methods, Gal alpha 1-3 Gal was demonstrated on interstitial and vascular trophoblast during pregnancy.

Fibronectin promotes lung colony formation in the mouse by B16 melanoma cells spheroids.

By microscopical observation and using an original method of automatic image analysis, we studied on histological sections the rate of lung colony formation after intravenous injection into the mouse of B16 melanoma cells previously cultivated in vitro as pure or mixed spheroids (B16 + 3T3 fibroblasts). The preincubation in vitro of pure spheroids with fibronectin significantly increased the percentages of lung section area occupied by tumors and the relative number of internal lung colonies. This effect of fibronectin was even more obvious when mixed spheroids were injected.

The human placenta becomes haemochorial at the 13th week of pregnancy.

Histological specimens of recent implantation sites are the basis of our current concept on human embryo implantation and placental development. In the Carnegie Collection maternal red blood cells were detected early in the primitive intervillous space (10th-12th day after conception). These cells were localized to the trophoblastic lacunae and originated from distended peripheral maternal sinusoids (Kaufmann, 1981).

The stimulation of fibroblasts' collagen synthesis by neoplastic cells is modulated by the extracellular matrix.

Human fibroblasts cocultured with neoplastic MCF7 cells produce increased amounts of collagen. A maximal stimulation requires direct cell-cell contacts between tumor cells and fibroblasts. However, this effect could be reproduced, although to a lesser extent, by medium conditioned by MCF7 cells, suggesting that it is mediated by a factor produced by MCF7 cells and secreted, at least partly, under a soluble form (Noël et al.

A histologic study of the extracellular matrix during the development of glomerulosclerosis in murine chronic graft-versus-host disease.

The development of glomerulosclerosis was studied in murine chronic graft-versus-host disease (GvHD), which is a model for human systemic lupus erythematosus. The authors investigated the distribution patterns of six components of the extracellular matrix (ECM), i.e.

Basement membrane components (matrigel) promote the tumorigenicity of human breast adenocarcinoma MCF7 cells and provide an in vivo model to assess the responsiveness of cells to estrogen.

The ability to transplant human tumors into athymic nude mice allows studies of tumor cells in vivo. However, after s.c.

[Human placental implantation].

Like malignant tumor cells, cells of the trophoblast, of the blastocyst and of the hemochorial placenta are highly invasive. This invasiveness is essential for implantation and penetration of the epithelial and connective tissues of the endometrium. According to Hertig's data and the observations (henceforth classical) of the Carnegie Foundation, it is commonly admitted that trophoblastic cells penetrate rapidly the blood vessels of the maternal endometrium, open them and allow the establishment of a communication between maternal circulation and fetal tissues from the 20th day after fertilization.

Influence of laminin or fibroblasts upon colony formation in the mouse by B16 melanoma cell spheroids: a morphometric analysis.

By microscopical observation and using an original morphometric method, we analyzed on histological sections the rate of lung colony formation after the intravenous injection into the mouse of B16 melanoma cells previously cultivated in vitro as aggregates. After the injection of B16 pure spheroids, superficial lung colonies were more numerous than internal lung colonies. After the injection of mixed spheroids (B16 + 3T3 fibroblasts), the size of colony sections was increased.

Modulation of collagen and fibronectin synthesis in fibroblasts by normal and malignant cells.

The influence of various normal and malignant human cells on the level of collagen synthesis by human fibroblasts was tested in coculture. As revealed by immunoperoxidase staining, in cocultures with breast adenocarcinoma cells (MCF7, SA52, T47D) fibroblasts synthesized collagen while tumor cells did not. Fibroblasts displayed increased collagen production without change in the overall protein synthesis.

Evaluation of in vitro reconstituted basement membrane assay to assess the invasiveness of tumor cells.

The crossing of tumor cells through basement membranes represents a critical step in the metastatic process. We have used a reconstituted basement membrane (matrigel) coated on filter in a Boyden chamber to assess the invasive potential of tumor and normal cells. No correlation was found between chemoinvasion in vitro and the metastatic potential in vivo.

Laminin binding and internalization by human and murine mammary gland cell lines in vitro.

We have studied the binding and internalization of Engelbreth-Holm-Swarm mouse sarcoma laminin labeled with colloidal gold (LN-G40) by human and murine mammary gland cell lines. Interactions between the LN-G40 probe and the cells spread on a glass coverslip were monitored with video-enhanced contrast microscopy (Nanovid). Transmission electron microscopy allowed the quantitation of the LN-G40 probe at various cellular locations.

Rat chromosome 5 (q22-23) contains elements that control cell morphology and interactions with the extracellular matrix: a study of normal fibroblast x malignant hepatoma cell hybrids.

Cell interactions with the extracellular matrix are consistently modified in neoplasia. Malignant transformation has been correlated with modifications in the synthesis and distribution of matrix components and with alterations of cell adhesive properties to these components. A particular class of genes, able to suppress the transformed phenotype in normal cells, may be involved in those phenotypic changes.

Arrest of MCF-7 cell migration by laminin in vitro: possible mechanisms.

Laminin, a major basement membrane component, arrested the migration of MCF-7/AZ human breast adenocarcinoma cells that were not invasive in vitro. Migration of invasive MCF-7/6 cells was not affected by laminin. Both cell types expressed the 67 kD laminin receptor, at both mRNA and protein level, but did not express the alpha 6 subunit of the VLA-6 integrin-type laminin receptor.

Efficacy of sustained-release vaginal oestriol in alleviating urogenital and systemic climacteric complaints.

In a double-blind, placebo-controlled study, 109 patients suffering from local and vasomotor postmenopausal complaints were randomly assigned to treatment with either depot vaginal suppositories containing 3.5 mg oestriol (E3) or a placebo. The treatment schedule comprised one vaginal suppository twice weekly for 3 weeks initially, followed by maintenance therapy with one vaginal suppository weekly for the 6-month study period.

Expression of laminin by human fibroblasts, HT1080 fibrosarcoma cells and MCF-7 breast adenocarcinoma cells. Lack of regulation by the cell density and extracellular matrix.

We have cultured normal fibroblasts, fibrosarcoma HT1080 cells and breast adenocarcinoma MCF-7 cells on various substrates (plastic, collagen type I, laminin). All cell types used adhered on the three substrates with, however, a delayed attachment on laminin. On all substrates, cell grew as monolayer with the exception of MCF-7 cells that formed clusters on laminin.

Malignant cell attachment to endothelium of ex vivo perfused human umbilical vein. Modulation by platelets, plasma and fibronectin.

The success of blood-born metastatic spread depends upon a key event: the tumor cell arrest and attachment to the host organ vasculature. In the present study, we have investigated interactions between several normal and cancer cell lines and vascular endothelium in a model of ex vivo perfusion of human umbilical vein. In this system, hydrodynamic parameters are monitored and endothelial cells are kept in their original environment known to modulate their phenotype.

Absence of laminin deposition in breast cancer and metastases except to the brain.

Laminin, a major glycoprotein of basement membrane has been found to play significant roles during invasion and metastases. In this study, we have examined the distribution of laminin in several human brain carcinoma metastases, human breast cancers, skin and lymph node metastases of breast cancer as well as in an in vitro and an in vivo model of invasion. A laminin accumulation was demonstrated a) at the border between human metastatic carcinoma cells and surrounding neural tissue; b) at the invasive edge between MO4 cells (a highly malignant cell line which synthesizes large amounts of laminin) and host tissues of syngenic mice; c) at the front of invasion between MO4 cells and precultured heart fragments in an in vitro model of invasion.

Influence of basement membrane molecules on directional migration of human breast cell lines in vitro.

Spheroidal cell aggregates were prepared from four tumorigenic human breast cell lines (HBL-100 and three MCF-7 variants). Cells from these aggregates were allowed to migrate towards lanes of basement membrane components coated on a glass substratum. Matrigel (reconstituted basement membrane) lanes permanently arrested the migration of one MCF-7 cell line, while migration of the others was permitted.

Evidence that the interaction between circulating IgA and fibronectin is a normal process enhanced in primary IgA nephropathy.

A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found that secretory, polymeric, and, to a much lesser extent, monomeric IgA exhibited elevated FN-BC as compared to their BC to plates coated with bovine serum albumin. This binding was specific since not observed with human IgG or IgM antibodies.

Invasion of reconstituted basement membrane matrix is not correlated to the malignant metastatic cell phenotype.

Interactions between tumor cells and basement membranes represent a critical step in the progression of neoplasia and in the metastatic process. Reconstituted basement membrane matrix, matrigel, has been recently used with the aim of developing an in vitro assay of tumor cell invasiveness. We have extended these studies by comparing the invasiveness of a large series of normal and malignant epithelial and mesenchymal cells of human and animal origin cultured on matrigel.

Effect of catechins and citrus flavonoids on invasion in vitro.

Catechins, a group of flavonoid molecules, inhibit invasion of mouse MO4 cells into embryonic chick heart fragments in vitro. The anti-invasive effects can be ranked as follows: (+)-catechin greater than (-)-epicatechin greater than 3-O-methyl-(+)-catechin greater than 3-O-palmitoyl-(+)-catechin. Most of the catechins are unstable in cell culture media, and their spontaneous rearrangement products tend to bind to extracellular matrix (ECM).