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Biomedical subjects

A Albini

Publications and source records attributed to A Albini.

At least 145 records · Page 8Linked to original sources
PubMed1989

Growth of cells from esophageal squamous cell carcinoma biopsies in a reconstituted basement membrane.

Cells from esophageal carcinoma biopsies were cultured on or inside a three-dimensional basement membrane matrix (matrigel). Their growth was compared to cells derived from control esophageal biopsies. Cells from both normal and neoplastic tissue attached poorly to tissue culture plastic. Matrigel coating improved adhesion and growth. When cells were grown inside a matrigel matrix, a striking difference was noticed between carcinoma cells and controls. Carcinoma cells grew invasively in the three-dimensional substrate and digested the matrix after a few weeks; control cells did not grow and only a few necrotic cells were visible with time. Matrigel provided a better growth substrate than plastic for esophageal derived cells and discriminated between carcinoma-derived and control cells when used as a three-dimensional growth substrate. Our studies suggest a possible use of matrigel for the selective growth of tumor cells derived directly from tissue biopsies.

Basement Membrane↗
PubMed1988

Differential regulation of growth and invasiveness of MCF-7 breast cancer cells by antiestrogens.

Estrogen increases the ability of the estrogen-dependent MCF-7 human breast cancer cell line to both proliferate and invade through an artificial basement membrane. In studying the response of MCF-7 cells to various antiestrogens, we found that 4-hydroxytamoxifen and tamoxifen inhibited cell proliferation but increased their invasiveness. In contrast, the structurally unrelated benzothiophene antiestrogens, LY117018 and LY156758, were potent antiproliferative agents which did not stimulate invasiveness. The differential effects of these antiestrogenic agents on invasion correlated with changes in production of collagenase IV, while no significant change was seen in the chemotactic activity of the cells. Invasiveness was increased by 17 beta-estradiol or 4-hydroxytamoxifen after a few hours of treatment and was rapidly lost when 17 beta-estradiol was withdrawn. Stimulation of invasiveness with 17 beta-estradiol was blocked by the antiestrogen, LY117018. Cells from the MDA-MB-231 line which lacks estrogen receptors were not affected by estrogen or antiestrogen in terms of proliferation or invasion. These studies indicate that the invasiveness of MCF-7 cells is regulated by antiestrogens through the estrogen receptor and may be mediated by collagenase IV activity. Antiestrogens which reduce both the proliferation and invasiveness of these cells may be interesting new candidates for clinical application.

Breast Neoplasms↗
PubMed1988

High chemotactic motility and growth in hard agar of a variant of RSV-transformed fibroblasts are lost in late passages.

Cloning efficiency in hard agar (0.6%) and high chemotactic migration toward fibroblast conditioned medium have been shown to characterize metastatic tumor cells. We studied growth in 0.6% agar and chemotaxis of two lines of Rous Sarcoma virus-transformed Balb/c3T3 cells, B77/3T3 (low metastatic) and AA12 (high metastatic), and compared them to their non-transformed counterpart, in order to verify whether these properties were maintained during several subcultivations. Cells were cryopreserved at early passages and thawed for experiments. Both assays were performed on freshly thawed cells (4-6 weeks in culture) and on cells which had been cultured 15-20 weeks after thawing. B77/3T3, which are tumorigenic but low metastatic and which have a very low cloning efficiency in hard agar (0.1-1%), showed a chemotactic response to Balb/c3T3 conditioned medium about two-fold higher than control Balb/c3T3. This response did not change with time in culture. AA12 cells, a genetic unstable variant of B77/3T3 selected for its growth in hard agar (0.6%), had a high cloning efficiency in hard agar and showed a high chemotactic motility (three-fold the controls). High growth in 0.6% agar and high chemotaxis of AA12 were lost in late passages, where cells behaved as the controls. It seems that besides the already reported variation in anchorage-independent growth, genetically unstable tumor cells can also have important variations in chemotactic motility during subcultivations.

Agar↗
PubMed1988

Invasive activity and chemotactic response to growth factors by Kaposi's sarcoma cells.

Kaposi's sarcoma (KS) is a relatively low grade neoplasm, classically occurring in the skin of elderly men. A more virulent and invasive form of Kaposi's sarcoma has been described in patients with acquired immune deficiency syndrome (AIDS). The origin and identification of the tumor cells in these lesions is controversial. Here we have studied the behavior of cells derived from KS lesions in an in vitro assay which measures the ability of cells to invade through a reconstituted basement membrane. In agreement with previous work, KS cells obtained under selective culture conditions were invasive showing activity comparable to that of malignant tumor cells. Normal fibroblasts, smooth muscle cells, and endothelial cells did not demonstrate invasive behavior under the same experimental conditions. To characterize further the nature of the KS cells we tested the chemotactic response of cells from the most invasive line to a variety of growth factors and compared their response to those of fibroblasts, smooth muscle, and endothelial cells. These studies suggest that normal cells respond to a unique repertoire of chemotactic factors. The chemotactic response of the KS cells most closely resembled that of smooth muscle cells and was quite distinct from endothelial cells. These results indicate that the KS-derived cultures contain invasive cells with a smooth muscle cell-like phenotype.

Biopsy↗
PubMed1988

Factors regulating basement membrane invasion by tumor cells.

Basement membranes serve as significant barriers to the passage of tumor cells but ones which metastatic cells can pass. This involves the production of a cascade of proteases leading to the activation of a specific collagenase that degrades the unique collagen network in basement membrane. Breast cancer cells, when estrogen dependent, show a requirement for estrogen for invasive activity. However, when these cells progress to an estrogen independent state and increased malignancy, they express an invasive phenotype constitutively. Studies with various anti-estrogens suggest that these responses are mediated via the estrogen receptor. Anti-estrogens lacking agonist activity suppress invasiveness as well as growth of the breast cancer cells.

Basement Membrane↗
PubMed1988

Decline of fibroblast chemotaxis with age of donor and cell passage number.

Human dermal fibroblasts have a limited life span in culture, which is manifested by a progressive decline of their proliferative activity. Here we show by the Boyden Chamber assay that the chemotactic response of human fibroblasts to fibroblast-conditioned medium and fibronectin declines during cellular aging in vitro and in vivo. The chemotactic response of human embryonic fibroblasts (HEF) declined progressively after the 25th passage. Virtually no chemotactic activity could be observed after the 40th passage in culture. Fibroblasts cultures from donors aged between 70-90 years had lost chemotactic activity by the 15th passage. Cells from patients suffering from progeroid syndromes of premature aging showed, even in early passages, a very low chemotactic response (20% of the HEF) and lost their chemotactic activity after a few subcultures. The response to the chemoattractant fibronectin also decreased with aging. Immunofluorescence studies indicated that the decline in chemotactic activity was accompanied by the formation of a thicker fibronectin network in the extracellular matrix of senescent human fibroblasts and progeroid cells than that observed in early passage embryonic cultures. Since fibroblast chemotaxis and synthesis of connective tissue components probably play an important role in tissue repair, our results could contribute to an understanding of age-related differences in the healing of skin wounds.

Aged↗
PubMed1987

A rapid in vitro assay for quantitating the invasive potential of tumor cells.

We have reconstituted a matrix of basement membrane onto a filter in a Boyden chamber and assessed the ability of various malignant and nonmalignant cells to penetrate through the coated filter. Cells from all the malignant cell lines tested were able to cross the matrix in 5-6 h, whereas human fibroblasts as well as mouse 3T3 and 10T1/2 cell lines, which are not tumorigenic, were not invasive. In addition, normal primary prostate epithelial cells and benign prostatic hyperplasia cells were not invasive when tested in this assay, whereas malignant prostate carcinoma cells were highly invasive. Parallel experiments with these prostatic cells using the intrasplenic assay for metastasis detection in the nude mouse confirmed the benign behavior of the former cells and the metastatic phenotype of the latter ones. These results suggest that this in vitro test allows the rapid and quantitative assessment of invasiveness and a means to screen for drugs which alter the invasive phenotype of tumor cells.

Animals↗
PubMed1987

Chemotaxis of 3T3 and SV3T3 cells to fibronectin is mediated through the cell-attachment site in fibronectin and a fibronectin cell surface receptor.

Fibronectin (FN) is a multidomain extracellular matrix protein that induces attachment and chemotactic migration of fibroblastic cells. In this study we analyzed the molecular determinants involved in the FN-induced chemotactic migration of normal and SV40-transformed 3T3 cells. Two different monoclonal antibodies to the cell-binding site of FN blocked chemotaxis to a 140-kD FN fragment (Ca 140) containing the cell-binding domain. A monoclonal antibody to a determinant distant from the cell-binding site did not affect chemotaxis. A synthetic tetrapeptide, RGDS, which represents the major cell-attachment sequence, was able to compete with FN and the Ca 140 fragment in chemotaxis assays, but this peptide itself had no significant chemotactic activity. A larger peptide encompassing this sequence, GRGDSP, was chemotactic, while the peptide GRGESP, where a glutamic acid residue was substituted for aspartic acid, was inactive. Chemotactic migration could be prevented in a dose-dependent manner by a rabbit polyclonal antiserum to a 140-kD cell surface FN receptor. This antibody was more effective on normal than on transformed 3T3 cells. Neither the anti-FN receptor antiserum nor a monoclonal antibody to the cell-binding site of FN blocked migration induced by another potent chemoattractant, platelet-derived growth factor. These data indicate that FN-induced chemotaxis of 3T3 and SV3T3 cells is mediated via the RGDS cell-attachment site of FN and the 140-kD cell surface FN receptor. The interaction is specific and can be altered by transformation.

Animals↗
PubMed1986

17 beta-estradiol regulates and v-Ha-ras transfection constitutively enhances MCF7 breast cancer cell interactions with basement membrane.

The interaction of a line of human breast carcinoma cells (MCF7) with basement membrane components, particularly laminin, was altered by exposure of the cells to estrogen as well as by transfection of the cells with the v-Ha-ras oncogene. In both cases, the cells show a greater ability to attach to a laminin substrate, to migrate to laminin, to grow in the presence of a basement membrane matrix, and to cross barriers of reconstituted basement membrane. These responses were associated with an increase in the expression of laminin receptors. It is postulated that the increase in the invasive behavior of the cells treated with estrogen or transfected with v-Ha-ras is related to the increased number of laminin receptors and their interaction with laminin. Estrogen had no discernible effect on the v-Ha-ras transfected cells. It appears that in the MCF7 cells, the malignant phenotype is under hormonal control and that this control is bypassed after v-Ha-ras transfection.

Basement Membrane↗
PubMed1985

SV40 transformed fibroblasts recognize the same 140 kD fibronectin chemotactic fragment as non-transformed cells.

SV40-virus-transformed human embryonal fibroblasts show an enhanced chemotactic response to the glycoprotein fibronectin. However, they recognize the same chemotactic active region as non-transformed fibroblasts. The result suggests that an enhancement of chemotaxis by fibroblasts which have been transformed with Simian Virus 40 is due not to the utilization of further chemotactic domains in the molecule, but to an increased sensitivity of the cells to the chemoattractant.

Cell Transformation, Viral↗
PubMed1985

Comparison of the chemotactic response to conditioned medium of BALB/c3T3 fibroblasts and their SV 40 transformants.

The chemotactic migration of transformed cells out of their tissue of origin might represent an essential component of tumor invasion and metastasis. In the Boyden chamber assay SV 40 virus-transformed BALB-c3T3 fibroblast (SV/3T3) showed an increased chemotactic response to fibroblasts-conditioned medium in comparison to non-transformed BALB/c3T3 cells. This was verified for a large range of incubation times and cell densities. Fibroblast-conditioned medium contains components of the extracellular matrix of connective tissue. Since organs rich in connective tissue are often the site of metastasis, the enhanced chemotaxis of virus-transformed cells to conditioned medium could contribute to explain the malignancy of these cells.

Animals↗
PubMed1985

The fibroblastic nature of dermatofibrosarcoma protuberans: morphological investigations in vivo and in vitro.

Six cases of dermatofibrosarcoma protuberans were studied ultrastructurally. Biopsy material from all six cases as well as cell cultures derived from four cases were examined. In all cases, the tumor cells in vivo and in vitro were related to fibroblasts. The two cases with histiocytoid features and a small spiral pattern exhibited numerous lipid vacuoles but no histiocytic cell markers. In these two cases, cultured cells contained a higher number of intracytoplasmic vacuoles than the control fibroblasts. Two other cases exhibited some basement-membrane-like material surrounding tumor cells. All of the investigated cell strains obtained from the tumors showed synthesis of collagenous proteins similar to that found in fibroblasts. However, the level of total collagen was reduced, and type-III collagen was absent. The morphological variations in these cases of dermatofibrosarcoma protuberans appeared to be related to the histological pattern and may reflect the heterogeneity of normal fibroblasts.

Adult↗
PubMed1985

Dermatofibrosarcoma protuberans: altered collagen metabolism in cell culture.

Dermatofibrosarcoma protuberans is a low-grade malignant tumor that grows invasively but rarely forms metastases. Its origin is still controversial. We characterized the synthesis of collagen in detail in cells which were obtained from dermatofibrosarcoma protuberans tumors by enzymatic tissue disintegration. Similar to fibroblasts, all tumor cell strains produced considerable amounts of collagen. However, the rate was reduced compared to normal skin fibroblasts. Cells grown from the tumors synthesized type I collagen, but no type II could be detected. After serial passaging the cultures started to produce type III collagen, which is probably due to a slow overgrowth by normal fibroblasts.

Cells, Cultured↗
PubMed1985

Collagenolytic cleavage products of collagen type I as chemoattractants for human dermal fibroblasts.

The chemoattractive properties of collagen in native (triple-helical) and denatured (random coil) conformation were compared in a Boyden chamber type assay to those of collagen fragments derived from cleavage with mammalian or bacterial collagenase using human embryonic dermal fibroblasts as target cells. Chemotaxis to native collagen required low collagen concentrations because fibril formation at high concentrations and at physiological pH and ionic strength prevented chemoattractiveness. Chemotaxis of denatured collagen was comparable to that of native collagen in solution. Cleavage of native collagen with mammalian collagenase increased, digestion with bacterial collagenase abolished its chemotactic activity. It is thought that these data may reflect the in vivo situation during inflammation and wound repair.

Cells, Cultured↗