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B B Asch

Publications and source records attributed to B B Asch.

48 records · Page 3Linked to original sources
PubMed1980

Distinction of normal, preneoplastic, and neoplastic mouse mammary primary cell cultures by water nuclear magnetic resonance relaxation times.

Normal, preneoplastic, and neoplastic primary cultures of mouse mammary epithelial cells were distinguishable on the basis of water proton nuclear magnetic resonance (NMR) relaxation times--i.e., spin-lattice relaxation time (T1) and spin-spin relaxation time (T2). T1 values were 916 +/- 24 msec for normal cells, 1,029 +/- 24 msec for preneoplastic cells, and 1,155 +/- 42 msec for neoplastic cells. This method of distinction between normal and neoplastic cells (P less than 0.001) and normal and preneoplastic cells (P less than 0.005) supported previous findings in whole tissues. NMR relaxation times resulted in better distinction between these cell populations than any other technique except direct histology. The T1 and T2 values of water protons in cells grown in primary culture were higher than those of established mouse mammary cancer cell lines. The differences in T1 and T2 did not correlate with cellular hydration. The data suggested a basic difference in water-macromolecular surface interactions among normal, preneoplastic, and neoplastic cells.

Animals↗
PubMed1980

Comparative responses of normal and malignant mouse mammary cells to modulation of surface properties.

We previously demonstrated that epithelial cells growing in primary cultures derived from normal and neoplastic mouse mammary tissues are indistinguishable on the basis of morphology, surface topography, agglutinability by concanavalin A, or of number, cytoplasmic location, or organization of microtubules and actin-containing microfilaments. In the present study, the modulation and interrelationships of these features were investigated using the drugs colchicine and cytochalasin B and the enzymes trypsin, collagenase, and hyaluronidase. Untreated cells of both types were only weakly agglutinable by concanavalin A. Pretreatment of the cells with colchicine, cytochalasin B, or hyaluronidase increased cytoagglutination by the lectin dramatically, whereas neither trypsin nor collagenase significantly altered reactivity of the cells. Binding studies utilizing fluorescein-tagged concanavalin A indicated that the enhanced agglutinability did not correlate with any particular distribution of lectin receptors on the cells. At the doses used, colchicine and cytocholasin B induced disruption of microtubules and microfilament networks, respectively, but no effects on either type of cytoskeletal element were observed after hyaluronidase, trypsin, or collagenase. The increased agglutinability was not associated with any specific surface conformation since scanning electron microscopy revealed that untreated cells and cells exposed to colchicine, hyaluronidase, and collagenase were flat and possessed variable numbers of small microvilli. In contrast, following incubation with cytochalasin B or trypsin, the cells underwent retraction and rounding, and developed complex surface structures such as blebs, ruffles, and filopodia. Thus, no single factor appeared responsible for determining the agglutinable or nonagglutinable state of the mammary cells. Morover, no differences were detected in the surface responses of the normal and malignant cells under any of the conditions used.

Animals↗
PubMed1980

Distinction between preneopastic and neoplastic mammary cell populations in vitro by cytochalasin B-induced multinucleation.

Epithelial cell cultures of normal mammary gland, preneoplastic hyperplastic nodule outgrowth lines, primary tumors, and transplanted tumors, all derived from BALB/c mice, were examined for their response to cytochalasin B to determine if cells of primary mammary tumors multinucleated and if preneoplastic hyperplastic alveolar nodule cells responded differently than cells of primary tumors. Established tumorigenic and nontumorigenic cell lines were also examined as positive and negative controls. The standard assay conditions were optimized at 1 microgram CB per ml for 48 hr. The results, expressed as the mean percentage of cells exhibiting three or more nuclei per cell were: normal mammary cells, 5%; preneoplastic mammary cells, 4%; primary mammary tumor cells, 36%; transplanted mammary tumors, 70%; tumorigenic established cell lines, 80%; and nontumorigenic established cell lines, 5%. The frequency of tumor cells exhibiting multinucleation increased with serial transplantation in vivo and with serial passage in vitro. The results demonstrate that neoplastic cells within a primary tumor exhibit uncontrolled nuclear division and that uncontrolled nuclear division is a distinguishing characteristic between preneoplastic and neoplastic mammary cells.

Animals↗
PubMed1979

Microtubules and actin-containing filaments of normal, preneoplastic, and neoplastic mouse mammary epithelial cells.

The distribution and organization of microtubules (MT's) and actin-containing microfilaments (MF's) were examined in epithelial cells of primary cultures established from normal, preneoplastic, and neoplastic mouse mammary tissues and in cells of three clonal culture lines derived from murine mammary adenocarcinomas. No consistent differences in the cytoskeletal components were found among cell populations of the primary cultures as revealed either by indirect immunofluorescence using antibodies to tubulin and actin or by electron microscopy. Overall, the majority of cells in the three types of primary cultures possessed elaborate complexes of MT's and actin filaments after fluorescent staining with the appropriate antibodies, and abundant MT's and MF's were found in the cells at the ultrastructural level. Similar patterns of MT's and MF's were observed in cells of two of the clonal mammary tumor lines. Cells of the third line, however, exhibited intricate networks of MT's but had a reduction in actin cables detectable by the immunofluorescence procedure. Moreover, MF's were difficult to locate by electron microscopy. The results suggest that the lesion(s) in growth control in the neoplastic mammary cells may not involve any gross alterations in MT's or MF's.

Actins↗
PubMed1978

Virus-specific markers and virus-like particles in cell lines of tumors produced by CELO virus in Syrian golden hamsters.

Cell lines were established from 2 primary hepatocellular carcinomas (HC's) and 3 sarcomas produced in Syrian golden hamsters inoculated as newborns with chicken embryo lethal orphan (CELO) virus. Cell lines from 2 sarcomas (COT, CMT) and 1 HC (CEHEP) produced CELO virus-specific T-antigen. The antigen was not detected in cells of the third sarcoma line (RCT) until they had undergone more than 34 passages in vitro. Although 5-10% of cells in the second HC line (CILT/2) contained T-antigen during early passages, it was not demonstrable after the fifth subculture. Nevertheless, cells of both HC lines possessed CELO virus tumor-specific transplantation antigen. All 5 cell lines also contained hamster type R particles, and both HC lines had type C and intracytoplasmic type A particles. The percentage of carcinoma cells producing type R particles increased during cultivation in vitro, whereas the number of cells with type A particles decreased. Treatment with dibutyryl cyclic AMP and theophylline enhanced the number of cells producing type C particles in 1 HC line and type R particles in 2 sarcoma lines.

Adenoviridae↗
PubMed1978

Chicken embyro lethal orphan (CELO) virus DNA present in hamster cell lines derived from CELO-induced hepatomas.

The kinetics of renaturation of the isolated DNA fragments of chicken embryo lethal orphan (CELO) virus generated by the restriction enzyme EcoR1 was measured in the presence of DNA extracted from two lines of CELO virus-induced hamster hepatoma cells and from control hamster cells. One hepatoma cell line (CILT-2), which did not produce the CELO virus tumor (T) antigen, lacked sequences from about one-half the virus genome while the other hepatoma cell line (CEHEP), which did produce the CELO virus T antigen, lacked sequences corresponding to one-fifth of the viral genome.

Adenoviridae↗
PubMed1978

Concanavalin A-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary cells.

The concanavalin A (Con A)-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary epithelial cells was examined. Cells freshly dissociated from normal mammary glands, hyperplastic alveolar nodules, or primary mammary adenocarcinomas by collagenase digestion in the presence of bovine serum albumin were strongly agglutinated by low concentrations of Con A. After short-term culture in vitro, however, cells from all three types of tissue were only weakly agglutinated by Con A, as measured by both suspension and hemadsorption assays. By comparison, cells of three established mammary tumor culture lines agglutinated strongly in the presence of the lectin. Treatment of the normal, preneoplastic, and neoplastic mammary cells in primary cultures with either trypsin or collagenase had little or no effect on their agglutinability, whereas hyaluronidase significantly increased their reactivity. Studies with fluorescein-tagged Con A indicated that all three cell types were capable of binding the lectin. The results were consistent with previous evidence suggesting that neoplastic transformation of mouse mammary epithelial cells is not manifested in vitro by several of the alterations in growth patterns, intercellular interactions, and surface properties that usually accompany transformation of fibroblastic cells.

Animals↗
PubMed1969

Accelerated plaque formation by fowlpox virus in the presence of chymotrypsin.

Chymotrypsin enhanced fowlpox virus plaque formation in chick embryo cell cultures. A simplified plaque assay for fowlpox virus is described. Plaques were produced in 3 days when chymotrypsin was included in a serum-free fluid overlay. Plaques were also produced in 5 to 6 days under an agar overlay when a medium containing fetal calf serum was employed. Kinetics of plaque formation were also studied, and it was shown that fowlpox virus plaque diameters grow at a linear rate.

Agar↗
PubMedDate not supplied

The influence of growth factors on the proliferative potential of normal and primary breast cancer-derived human breast epithelial cells.

In previous studies, we developed serum-free, bovine pituitary extract (BPE)-free culture conditions for the growth of normal and neoplastic rat mammary epithelial cells. The present studies were aimed at determining if these culture methods could be used to study the influence of specific growth factors on the proliferative potential of normal human mammary epithelial (HME) cells and cells derived from human breast cancer (HBC) specimens. Our results indicate that normal HME cells in primary culture express stringent requirements for insulin (IN), epidermal growth factor (EGF), and cholera toxin (CT). Of these factors, EGF is most important, with essentially no proliferation taking place in the absence of this factor. By contrast, when cells are grown in serum-free primary culture in the presence of a full complement of growth factors and then subcultured, growth in secondary culture is not influenced by the removal of individual growth factors. Growth in secondary culture in the absence of EGF is mediated by autocrine factors secreted by the cells. However, there is no evidence for autocrine activity that mediates growth in the absence of IN in secondary cultures. Primary culture of HBC cells in serum-free, BPE-free medium revealed two patterns of growth factor requirements. One set of HBC cells expressed identical requirements for IN and EGF in primary culture as normal cells. Likewise, these cells grew in secondary culture in the absence of either factor. The second set of tumors expressed independence of IN for growth in primary culture. These cells grew to confluence in primary culture in the absence of IN and could be subcultured in this medium. All tumor cells examined expressed a requirement for EGF for primary culture growth, whereas none of the HBC cells examined expressed a significant CT requirement. In many cases, growth in the absence of CT exceeded that observed in its presence. Thus, our culture system allows analysis of the growth factor requirements of HME and HBC cells in primary culture. Our results indicate significant differences between HME and HBC cells in this regard. However, the results of secondary culture experiments indicate that the growth factor milieu from which cells are taken can have a profound effect on the requirements for growth factors in culture.

Breast↗