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B Persky

Publications and source records attributed to B Persky.

15 recordsLinked to original sources
PubMed1990

Artificial matrix barriers: a diffusion study utilizing dextrans and microspheres.

Eight artificial matrices (AMs) were evaluated for the ability to restrict the passage of diffusion probes. Three AMs were composed exclusively of interstitial type I collagen (Col I) and differed from each other in thickness only. Four AMs consisted of reconstituted basement membrane (RBM) -coated polycarbonate filters (containing 10 microns diameter pores) and also only differed in thickness. One AM consisted of an uncoated 10 microns pore polycarbonate filter. The diffusion probes were uncharged fluorescein isothiocyanate-labeled dextrans, having molecular weights of 17,900, 42,000, 71,200, and 148,900 and negatively charged latex microspheres, having diameters of 0.08, 0.30, and 0.95 microns. Probes were applied to the AMs, incubated for 72 hr at 37 degrees C, and then analyzed spectrophotometrically. Dextran passage was increasingly restricted for Col I matrices as either molecular weight or collagen thickness increased (range 7% to 0.7%). Thin RBM-coated filters were more permeable to dextrans (range 100% to 30%) than Col I matrices. The diffusion rate of microspheres for Col I matrices (range 3.5% to 0) was similar to both thick and thin RBM-coated filters (range 4% to 0). The uncoated filter permitted the most diffusion for both dextrans and microspheres (range 100% to 7%). These data demonstrate that the AMs presented in this study will allow direct observation of the degradative and migratory potential of cells in vitro as they interact with various extracellular matrices.

Animals↗
PubMed1990

A quantitative assessment of F-actin content and distribution in untreated and butyric acid treated murine melanoma B16a tumour cells: a fluorescence image analysis study.

Image analysis of phallacidin, a fluorescent stoichiometric probe to F-actin, permitted the cytoskeletal-associated actin 'F-actin' to be visualized morphologically and to be divided into two groups, diffuse and filamentous. The filamentous actin group was categorized further into four subgroups according to the intensity of the phallacidin probe. F-actin groups and subgroups of untreated cells and cells treated with 1.5 mM butyrate acid were analysed independently. Butyric acid treatment significantly increased total actin, defined as diffuse actin, plus filamentous subgroup actins 1-4. Specifically, butyric acid-treatment increased filamentous subgroup actin 1.

Actins↗
PubMed1990

The influence of ethanol on cell membrane fluidity, migration, and invasion of murine melanoma cells.

The short-term effects of ethanol (85.4, 170.8, and 256.2 mM) on cellular viability, proliferation, migration, and invasion were investigated on murine melanoma cells. Experiments with the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene indicated that the two highest concentrations of ethanol induced low microviscosity (high lipid fluidity). Cellular viability and proliferation, as determined by the incorporation of [3H]IdUR, were unaffected by all three concentrations of ethanol. A membrane migration assay and a collagen type IV invasion assay evaluated cellular migration and invasion, respectively. For B16F10 and K1735 cells, the migration rate was significantly increased by 170.8 and 256.2 mM concentrations of ethanol. Although the invasion of B16F10 cells was not affected, invasion of K1735 cells was inhibited by 170.8 and 256.2 mM ethanol. The effect of ethanol on the cytoskeleton was monitored by fluorescent staining of F-actin. In contrast to untreated cells, F-actin staining of 256.2 mM ethanol-treated cells showed spike-like projections from the cell surface. Our findings suggest that ethanol can influence cell migration and invasion in vitro, as well as F-actin organization.

Actins↗
PubMed1989

Immunohistochemical and ultrastructural study of human melanoma colonies grown in soft agar.

An immunohistochemical and ultrastructural study of human melanoma colonies grown in soft agar for up to 50 days was performed. Three morphological variants of developing tumor colonies are reported: 1) large light colonies, 2) small dark colonies, and 3) smooth-edged colonies. The large light colony variant is the most frequently observed in the soft agar assay (approximately 70%), followed by the dark colony variant (approximately 27%), and the smooth-edged colony variant (approximately 3%). Major morphological characteristics are associated with each variant, as shown with light microscopy (LM) and transmission electron microscopy (TEM). Both LM and TEM analyses demonstrated that the large light colony variant was hypomelanotic and contained a microfibrillar extracellular matrix (ECM). The small dark colony variant was found to be hypermelanotic and contained a less demonstrable ECM. The smooth-edged variant has an encapsulated periphery, no demonstrable ECM, and tightly packed cells with desmosome-like junctions. In order to characterize further the ECM in the most commonly observed variant, the large light colony, specific antibodies to fibronectin (FN) and collagen types IV and V (COLs IV and V) were applied and observed with immunofluorescence microscopy and immunoperoxidase. In paraffin sections of melanoma colonies, FN was observed associated with both the cell surface and the ECM. However, no specific staining was seen for COLs IV and V. In addition, ruthenium red was used to preserve and selectively bind to glycosaminoglycans (GAGs) and proteoglycans (PGs). TEM studies reveal GAG-like granules stained with ruthenium red in the fibrillar ECM and a dotted, punctate staining of the cell surface. Understanding the biological and architectural composition of developing melanoma tumor colonies in soft agar could contribute to the development of more efficient chemotherapeutic strategies.

Agar↗
PubMed1989

The effects of retinoic acid and butyric acid on in vitro migration by murine B16a cells: a quantitative scanning electron microscopic study.

Retinoic acid (RA) and butyric acid (BA) were investigated for their effect on in vitro migration of highly metastatic murine B16a melanoma cells. These potential antitumor agents are known to alter the cytoskeleton. Our initial studies determined the 72 h cytostatic/cytotoxic concentrations of RA (1 X 10(-6) M 1 greater than 1 X 10(-5) M) and BA (1.5 mM)/ greater than 2.0 mM). Cytostasis by RA and BA was confirmed by autoradiography and radioisotope incorporation. For migration assays, cells were plated on 3 and 5 microns diameter pore polycarbonate membranes. Complete media was added containing RA or BA at time of plating. For BA pretreatment studies, BA was added to cells for 72 h prior to plating cells in fresh BA on the membranes. Top and bottom surface of the membranes were examined after 72 h of incubation by scanning electron microscopy. Although RA and BA induced cells on top of the membrane to change morphology as shown by phase, transmission and scanning electron microscopy, only BA enhanced the deformability of cells to allow for passage through the 3 micron diameter pores. Butyric acid enhanced migration through 3 micron diameter pore membrane by 511%. For 5 micron diameter pore membranes, 55.2% of the plated number of untreated early passage cells migrated to the bottom surface as compared to 57.3% for BA-treated cells and 14.9% for RA-treated cells. However, if cellular proliferation over the 72 h period was factored in, BA increased migration by 456% over the controls and pretreatment of cells with BA for 72 h prior to plating increased migration by 893%. Without considering proliferation, RA inhibited migration by 75% over controls. The decrease in migration observed in RA-treated cells was due to an inhibitory effect on cellular migration and a decrease in proliferation.

Animals↗
PubMed1988

Inhibition by human recombinant tissue inhibitor of metalloproteinases of human amnion invasion and lung colonization by murine B16-F10 melanoma cells.

The human tissue inhibitor of metalloproteinases (TIMP) is a glycoprotein with a molecular weight of 28,000. It appears to be ubiquitous in human mesoderm tissues and has previously been shown to be identical to the collagenase inhibitor isolated from human skin fibroblasts. TIMP inhibits type I- and IV-specific collagenases and other neutral metalloendoproteinases that may be responsible for the degradation of extracellular matrix in tumor cell metastasis. In this work we have utilized recombinant human TIMP (rTIMP) obtained by expression of its cDNA gene (Carmichael et al., Proc. Natl. Acad. Sci. USA, 83:2407, 1986). The rTIMP is shown to have similar inhibition properties as natural TIMP against human skin fibroblast collagenase. In an in vitro amnion invasion assay system, rTIMP inhibited the invasion of B16-F10 murine melanoma cells through the human amniotic membrane at an identical concentration to that reported previously for natural TIMP. The mechanism by which rTIMP inhibits amniotic membrane invasion was compared to the mechanism by which the fibronectin receptor binding peptide RGDS and the aminin receptor binding peptide YIGSR inhibit amnion invasion. RGDS and YIGSR inhibited strong binding of the tumor cells to the amniotic membrane. In contrast rTIMP did not inhibit the cell adhesion step in amnion invasion, but actually increased the number of tumor cells that were tightly bound to the amnion. Thus rTIMP appears to inhibit a later step in the amnion invasion process, following B16-F10 cell adhesion. C57BL/6 mice treated with i.p. injections of rTIMP every 12 h for 6.5 days showed a significant inhibition of metastatic lung colonization by B16-F10 murine melanoma cells. While the rTIMP inhibited the number of metastatic lung tumors formed, it had no significant effect on the size of the lung tumors. Furthermore, tumors grown s.c. in mice receiving 12-h i.p. injections of rTIMP for 6.5 days, as in the in vivo colonization assay, showed no difference in size from controls. Thus the anticolonization effect of rTIMP appears not be due to an effect on tumor growth, but on the invasion step itself. The inhibition of lung colonization in C57BL/6 mice by rTIMP is one of the first examples showing an antimetastatic effect of a selective metalloproteinase inhibitor in a mammalian animal model, and supports an essential role for metalloproteinase(s) in the extravasation and invasion of tumor cells during lung colonization by blood-borne tumor cells.

Amnion↗
PubMed1987

Morphological characterization of cellular and extracellular components of 7,12 dimethylbenz[a]anthracene induced melanoma tumours.

Subcutaneous tumours were induced in castrated golden Syrian hamsters by 7,12 dimethylbenz[a]anthracene (DMBA), an agent known to produce papillomas and carcinomas. The morphological characteristics of the cellular and extracellular constituents of the chemically-induced tumours were indicative of melanoma. Tumours were induced by three injections of DMBA into the jugular vein over a 3 month period. Dermal tumour development within the dorsal integument and groin region ultimately projected into the epidermis and occurred during the 3 month period subsequent to the last DMBA injection. Suspect melanoma tumours were excised and processed for light microscopic (LM) and transmission electron microscopic (TEM) studies. Histochemical staining methods facilitated the characterization of the differentiated tumour components in this hamster melanoma model. The model presented could allow observations from initial melanoma transformation events through advanced stages of metastasis within a window of 7 months.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

A comparative study on in vitro invasion rates by melanoma cells in the human amniotic basement membrane model versus in vivo tumor nodule formation in C57BL6 mice.

Invasion by murine B16-F10 melanoma cells was studied using the human amniotic basement membrane (HABM) assay. B16-F10 cells were collected after a single passage through the amnion and grown to near confluency. The cycle of plating, passaging, collecting, and culturing B16-F10 cells was repeated five times. The invasion rate for B16-F10 cells remained relatively unchanged after six passages through the amnion. Injection of first-passage B16-F10 cells into C57BL6 mice resulted in 29 lung tumors per animal whereas sixth-passage cells resulted in 300+ lung tumors. While there exists no correlation of the number of cells penetrating the amnion with colonization number, lung colonization appears correlated with increased number of passages through the amnion.

Amnion↗
PubMed1986

Inhibition of proteolytic enzymes in the in vitro amnion model for basement membrane invasion.

The ability of B16-F10 mouse melanoma cells to cross an amnion basement membrane was determined in the presence of strong inhibitors of both serine and cysteine proteases. The concentrations of inhibitors were at orders of magnitude higher than their Ki values to serine and cysteine proteases implicated in metastasis, thus ensuring a complete inhibition for tumor secreted proteases such as cathepsin B-like proteases, plasminogen activators, and plasmin. Under these conditions of high serine and cysteine protease inhibitor concentrations, no significant decrease in B16-F10 melanoma cell invasion through the amnion was observed. Separate experiments showed that the inhibitors were neither toxic to the cells nor degraded. The results show that neither tumor cell secreted cathepsin B-like proteases nor plasminogen activator have a controlling role in basement membrane crossing in this metastatic model. A possible role for tumor cell membrane proteases in basement membrane invasion, in which the substrates of the protease bind to receptor sites near a membrane associated proteolytic activity, is not eliminated.

Amnion↗
PubMed1985

Scanning electron microscopy of the subarachnoid space in the dog: inflammatory response after injection of defibrinated chicken erythrocytes.

The leptomeningeal reaction and the cerebrospinal fluid reaction of the canine inflammatory response were investigated concurrently. One-half milliliter cerebrospinal fluid (CSF) was withdrawn from the cisterna magna of 17 anesthetized mongrel dogs and analyzed. Using this same spinal tap, control and experimental animals were injected with 0.5 ml sterile saline and 0.5 ml defibrinated chicken erythrocytes, respectively. A second spinal tap was performed 2 to 168 hr later. The CSF from the first spinal tap contained less than 1 WBC/mm3. The cell population was unchanged in the second spinal tap of control animals. In experimental animals, the WBC population increased more than 100-fold by 24 hr. Polymorphonuclear cells (PMNs) appeared in the CSF first, followed by lymphocytes and monocytes. Injected erythrocytes seemed trapped in the subarachnoid space (SAS), especially in the inner sheet of the arachnoid mater. The leptomeninges had a substantial increase in free cells without fibrosis. Pial and leptomeningeal cells of the arachnoid trabeculae appeared swollen. Two hours after injection, chicken erythrocytes were phagocytosed by pial cells, macrophages, and free cells adherent to the leptomeninges. The epiplexus cell populations for saline-control and erythrocyte-experimental animals were similar, suggesting that the choroid plexuses were not a gateway for PMN, lymphocyte, or monocyte infusion into the SAS.

Animals↗
PubMedDate not supplied

The effect of butyric acid and retinoic acid on invasion and experimental metastasis of murine melanoma cells.

The effect of butyric acid (BA) and all trans-retinoic acid (RA) on murine melanoma cells was investigated in vitro and in vivo. The in vitro assays included 3H-IdUR incorporation, adhesion, migration and invasion experiments. Butyric acid decreased 3H-IdUR cellular incorporation within 24 h and increased adhesion as measured by trypsin release of 3H-IdUR labelled cells from either polycarbonate (p.c.) or Matrigel-coated p.c. membranes. Migration and invasion rates after 72 h were quantified by scanning electron microscopy (SEM). The invasion barrier consisted of Matrigel-coated p.c. membranes. Butyric acid significantly enhanced migration and invasion of B16a cells, while RA significantly decreased migration and invasion of B16a and K-1735 cells. Subcutaneous administration of either BA or RA pellets significantly decreased the number of lung nodules in the experimental metastatic assay. The experimental metastatic assay is defined as a tail vein inoculation protocol followed by subsequent lung evaluation.

Animals↗
PubMedDate not supplied

Diffusion of dextrans and microspheres in the human amniotic basement membrane model.

The human amniotic basement membrane model was utilized to determine diffusion ratios of dextrans and beads according to size selectivity. Diffusion through both intact and denuded amnions was determined after 24 and 72 h. Four neutrally charged fluorescein isothiocyanate labeled dextrans, having molecular weights of 17,900, 42,000, 71,200 and 156,000, diffused through the amnion. The amnion functioned as a sieve in that the passage of dextrans was increasingly restricted as molecular weight increased. In contrast, uncharged latex microspheres (1.05 micron +/- 0.07 micron (SD] and fluorescent carboxylated microspheres (1.57 micron +/- 0.13 micron (SD] failed to pass through the amnion. Light and electron microscopy revealed no preformed channels through which the 1.05 micron microspheres could pass through the amnion. Statistical analysis of cross-sectional thickness of individual and similarly treated amnions (intact or denuded) showed a difference in thickness (P = 0.05).

Amnion↗