cytochalasin-b and Neoplasms

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Asparaginase; Cell Division; Cyclic AMP; Cycloleucine; Cytochalasin B; Drug Therapy, Combination; Emetine; Growth Inhibitors; In Vitro Techniques; Mice; Neoplasms; Puromycin Aminonucleoside

Topics: Animals; Cell Adhesion; Cell Membrane; Cell Separation; Chick Embryo; Cornea; Cytochalasin B; Cytoplasmic Granules; Desmosomes; Embryo, Mammalian; Extracellular Space; Humans; Neoplasms

Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) are of interest as a new vector for the delivery of therapeutic agents into the tumor microenvironment. Cell-free EV-based therapy has a number of advantages over cell-based therapy, since the use of EVs allows avoiding potential undesirable transformation associated with MSCs. MSC-derived EVs can transfer natural proteins with immunomodulatory or antitumor properties. The aim of this study was to produce vesicles from mesenchymal stem cells with simultaneous overexpression of TRAIL, PTEN and IFN-β1 and analyze its antitumor and immunomodulatory properties. In this work, a stable line of human adipose tissue-derived mesenchymal stem cells (hADSCs) with simultaneous overexpression of TRAIL, PTEN and IFN-β1 was produced. To obtain this cell line hADSCs were genetically modified with a genetic multicistronic cassette encoding TRAIL, PTEN, and IFN-β1 genes separated with a self-cleaving P2A peptide nucleotide sequence. Membrane vesicles (CIMVs) were obtained from genetically modified hADSCs using cytochalasin B treatment. Antitumor and immunomodulatory properties of the CIMVs were analyzed in vitro. It was shown that CIMVs isolated from genetically modified hADSCs overexpressing TRAIL, PTEN and IFN-β1 genes are able to activate human immune cells and induce apoptosis in various types of carcinomas in vitro. Thus, the immunomodulatory and antitumor properties of CIMVs were shown. However, further studies on animal models in vivo are required.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cytochalasin B; Extracellular Vesicles; Gene Expression Regulation, Neoplastic; Humans; Immunomodulation; Immunophenotyping; Interferon-beta; Lymphocyte Activation; Mesenchymal Stem Cells; Neoplasms; PTEN Phosphohydrolase; RNA, Messenger; T-Lymphocytes; TNF-Related Apoptosis-Inducing Ligand

To elucidate the interactions, uptake mechanisms and cytotoxicity profile of glucose-functionalized gold nanoparticles (2GF-GNPs), for expanding and advancing the recently proposed technology of metabolic-based cancer detection to a variety of cancer diseases.. Several cell types with different metabolic features were used to assess the involvement of GLUT-1 and different endocytosis pathways in 2GF-GNP uptake, and the cytotoxicity profile of 2GF-GNPs.. Cellular uptake of 2GF-GNP strongly correlated with GLUT-1 surface expression, and occurred mainly through clathrin-mediated endocytosis. 2GF-GNPs showed no toxic effect on cell cycle and proliferation.. These findings promote development of metabolic-based cancer detection technologies, and suggest that 2GF-GNPs may enable specific cancer detection in a wide range of tumors characterized by high GLUT-1 expression.

Topics: A549 Cells; Cell Cycle; Cell Proliferation; Contrast Media; Cytochalasin B; Endocytosis; Gene Expression Regulation, Neoplastic; Glucose; Glucose Transporter Type 1; Gold; Humans; Metal Nanoparticles; Neoplasms; Tomography, X-Ray Computed

Continuing study of the ethyl acetate (EtOAc) extract of the cultured soft coral Sinularia brassica afforded five new withanolides, sinubrasolides H-L (1-5). The structures of the new compounds were elucidated on the basis of spectroscopic analysis. The cytotoxicities of new compounds 1-5 and a known compound sinubrasolide A (6) against the proliferation of a limited panel of cancer cell lines were assayed. The anti-inflammatory activities of compounds 1-6 were evaluated by measuring their ability to suppress N-formyl-methionyl-leucyl-phenyl-alanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release in human neutrophils.

Topics: Animals; Anthozoa; Anti-Inflammatory Agents; Antineoplastic Agents; Cell Line, Tumor; Cytochalasin B; Humans; Models, Molecular; Neoplasms; Neutrophils; Pancreatic Elastase; Superoxides; Withanolides

The dose-responses of micronuclei (MN) in binucleated (BN) and mononucleated (MONO) lymphocytes cultivated with cytochalasin B (CBMN-assay) were studied. Irradiation of lymphocytes was performed in vitro (donor A) at the single dose of 1 and 2 Gy of (60)Co y-rays, or in vivo, during whole-body exposure of a cancer patient (donor B) to (60)Co γ-rays each day at a single dose of 0.115 Gy up to a total dose of 1.15 Gy. The linear dose-response for MN was determined in both BN and MONO lymphocytes of donor B. It means that when CBMN assay is applied, the MN in MONO cells represent those preexisted in vivo before each exposure. On the contrary, in lymphocytes of donor A irradiated in vitro an essential elevated MN yield with an - increased dose was observed only in BN lymphocytes. A slight dose dependent elevation of MN in MONO cells seems to be due to either their division before cytochalasin was introduced in the culture medium or their insensitivity to the CB block of cytokinesis.

Topics: Adult; Cobalt Radioisotopes; Cytochalasin B; Dose-Response Relationship, Radiation; Gamma Rays; Humans; Lymphocytes; Male; Micronuclei, Chromosome-Defective; Neoplasms

Background Despite inherent differences between the cytoskeletal networks of malignant and normal cells, and the clinical antineoplastic activity of microtubule-directed agents, there has yet to be a microfilament-directed agent approved for clinical use. One of the most studied microfilament-directed agents has been cytochalasin B, a mycogenic toxin known to disrupt the formation of actin polymers. Therefore, this study sought to expand on our previous work with the microfilament-directed agent, along with other less studied cytochalasin congeners. Materials and Methods We determined whether cytochalasin B exerted significant cytotoxic effects in vitro on adherent M109 lung carcinoma and B16BL6 and B16F10 murine melanomas, or on suspension P388/ADR murine leukemia cells. We also examined whether cytochalasin B, its reduced congener 21, 22-dihydrocytochalasin B (DiHCB), or cytochalasin D could synergize with doxorubicin (ADR) against ADR-resistant P388/ADR leukemia cells, and produce significant cytotoxicity in vitro. For in vivo characterization, cytochalasins B and D were administered intraperitoneally (i.p.) to Balb/c mice challenged with drug sensitive P388-S or multidrug resistant P388/ADR leukemias. Results Cytochalasin B demonstrated higher cytotoxicity against adherent lung carcinoma and melanoma cells than against suspension P388/ADR leukemia cells, as assessed by comparative effects on cell growth, and IC₅₀ and IC₈₀ values. Isobolographic analysis indicated that both cytochalasin B and DiHCB demonstrate considerable drug synergy with ADR against ADR-resistant P388/ADR leukemia, while cytochalasin D exhibits only additivity with ADR against the same cell line. In vivo, cytochalasins B and D substantially increased the life expectancy of mice challenged with P388/S and P388/ADR leukemias, and in some cases, produced long-term survival. Conclusion Taken together, it appears that cytochalasins have unique antineoplastic activity that could potentiate a novel class of chemotherapeutic agents.

Topics: Animals; Antineoplastic Agents; Cell Survival; Cytochalasin B; Cytochalasin D; Cytochalasins; Doxorubicin; Drug Synergism; Leukemia P388; Lung Neoplasms; Melanoma; Mice; Mice, Inbred BALB C; Neoplasms; Tumor Cells, Cultured

This study confirmed that the frequency of human lymphocyte biomarkers measured with the cytokinesis-block micronucleus cytome (CBMNcyt) assay, is associated with age, sex, and lifestyle factors. Cytogenetic analysis was carried out on samples from 100 healthy individuals living in Bosnia and Herzegovina. Cells were cytologically scored for viability status, defined by the proportion of necrotic and apoptotic cells; mitotic status, corresponding to the proportion and ratios of mono-, bi- and multinucleated cells; the nuclear division index and chromosomal damage, determined by the presence of micronuclei, nucleoplasmic bridges or nuclear buds of bi-nucleated cells. Ageing is positively associated with the frequency of cytogenetic biomarkers. The micronucleus frequency in females was significantly higher than the micronucleus frequency in males. The micronucleus frequency is positively associated with family history of cancer. Furthermore, it is positively correlated with smoking: the frequency is higher in male subjects with a smoking habit than in female smokers. However, alcohol is observed to decrease the frequency of apoptotic cells in human lymphocytes. The frequency of micronuclei was positively correlated with exposure to medication. Lastly, the frequency of nuclear buds and apoptotic and necrotic cells negatively correlated with exposure to radiation.

Topics: Adolescent; Adult; Age Factors; Aged; Aging; Alcohol Drinking; Apoptosis; Bosnia and Herzegovina; Cell Division; Cell Survival; Cytochalasin B; Cytokinesis; DNA Damage; Environmental Exposure; Female; Humans; Incidence; Life Style; Lymphocytes; Male; Micronuclei, Chromosome-Defective; Micronucleus Tests; Middle Aged; Neoplasms; Sex Factors; Smoking; Young Adult

Chromosomal instability could be one of primary causes for malignant cell transformation. The objective of the present study was to evaluate the spontaneous genetic damages in circulated lymphocytes of newly diagnosed cancer patients by using cytokinesis-block micronucleus (CBMN) assay, with respect to the factors that might affect micronucleus frequency (i.e. age, gender, smoking habits and cancer sites). Micronuclei (MN) are small nuclei that are originated from chromosome fragments or whole chromosomes. The analyzed samples included 44 untreated cancer patients (19 females and 25 males with mean age of 60.89 years) with different cancer sites (12 patients with breast cancer, 5 with uterine cancer and 27 with cancer of pharynx). Control group included 40 healthy donors (28 females and 12 males with mean age of 43.95 years). The mean baseline MN frequency was significantly higher (p < 0.001) in cancer patients (15.18 +/- 5.05 MN/1000 BN cells ranging from 4 to 27) than the baseline frequency in healthy controls (6.45 +/- 2.75 MN/1000 BN cells, ranging from 1 to 11). There was no gender difference in baseline MN frequency in cancer patients and healthy controls. Moreover, the MN frequency did not significantly differ among cancer sites, and between smokers and non-smokers in both patient and control samples. In conclusion, untreated cancer patients may be associated with an increase of chromosomal instability in peripheral blood lymphocytes, irrespective of gender, cigarette smoking and cancer sites.

Topics: Adult; Aged; Aged, 80 and over; Aging; Breast Neoplasms; Chromosomal Instability; Cytochalasin B; Cytokinesis; Female; Humans; Leukocytes, Mononuclear; Male; Micronuclei, Chromosome-Defective; Micronucleus Tests; Middle Aged; Neoplasms; Organ Specificity; Pharyngeal Neoplasms; Sex Characteristics; Smoking; Uterine Neoplasms

Metabolic control analysis of tumor glycolysis has indicated that hexokinase (HK) and glucose transporter (GLUT) exert the main flux control (71%). To understand why they are the main controlling steps, the GLUT and HK kinetics and the contents of GLUT1, GLUT2, GLUT3, GLUT4, HKI, and HKII were analyzed in rat hepatocarcinoma AS-30D and HeLa human cervix cancer. An improved protocol to determine the kinetic parameters of GLUT was developed with D-[2-(3)H-glucose] as physiological substrate. Kinetic analysis revealed two components at low- and high-glucose concentrations in both tumor cells. At low glucose and 37 degrees C, the V(max) was 55 +/- 20 and 17.2 +/- 6 nmol (min x mg protein)(-1), whereas the K(m) was 0.52 +/- 0.7 and 9.3 +/- 3 mM for hepatoma and HeLa cells, respectively. GLUT activity was partially inhibited by cytochalasin B (IC(50) = 0.44 +/- 0.1; K(i) = 0.3 +/- 0.1 microM) and phloretin (IC(50) = 8.7 microM) in AS-30D hepatocarcinoma. At physiological glucose, GLUT1 and GLUT3 were the predominant active isoforms in HeLa cells and AS-30D cells, respectively. HK activity in HeLa cells was much lower (60 mU/mg protein) than that in AS-30D cells (700 mU/mg protein), but both HKs were strongly inhibited by G6P. HKII was the predominant isoform in AS-30D carcinoma and HeLa cells. The much lower GLUT V(max) and catalytic efficiency (V(max)/K(m)) values in comparison to those of G6P-sensitive HK suggested the transporter exerts higher control on the glycolytic flux than HK in cancer cells. Thus, GLUT seems a more adequate therapeutic target.

Topics: Animals; Biological Transport; Catalysis; Cell Line, Tumor; Cell Proliferation; Cold Temperature; Cytochalasin B; Cytosol; Female; Glucose; Glucose Transport Proteins, Facilitative; Glucose-6-Phosphate; Glycolysis; HeLa Cells; Hexokinase; Humans; Insulin; Isoenzymes; Kinetics; Mitochondria; Neoplasms; Phloretin; Phosphorylation; Rats; Rats, Wistar

The recent development of an electronic test system based on silicon sensor-chips allows the continuous parallel recording of relative changes in extracellular acidification, oxygen consumption and electric impedance in living cells. The objective of this proof-of-principle study therefore, was to clarify whether this system can also be applied to live tissue slices thus providing a device for an ultimately envisioned chemosensitivity testing apparatus for individualized treatment schemes in cancer therapy. A prototype of the testing apparatus equipped with six individual measuring devices has been used to simultaneously analyze changes in extracellular acidification, oxygen consumption and electronic impedance in live liver tissue and compared to data obtained from a tumor cell line. In contrast to tumor cells, tissue slices showed low rates of extracellular acidification but high rates of oxygen consumption. Monitoring of electrical impedance values, reflecting cellular morphology, revealed that the compact cell structure of the tissue slices was able to function as electric insulator and actively change the impedance values of the system. Exposure of tumor cells to 1 microM cytochalasin B, a fungal metabolite known to interact with the cytoskeleton and influence glucose metabolism, resulted in the rapid decline of extracellular acidification, increased oxygen consumption rates and increased values in capacitance. In tissue slices upon addition of 1 microM cytochalasin B, a decline of both extracellular acidification and electrical impedance was observed within 1 h. Determination of ATP content in the tissue slices revealed that decreasing ATP content paralleled diminishing oxygen consumption. This new technique offers the possibility of generating metabolic profiles for cells and tissues by studying oxygen consumption, extracellular acidification and electrical impedance.

Topics: Acid-Base Equilibrium; Adenosine Triphosphate; Animals; Cell Line, Tumor; Cytochalasin B; Electric Impedance; Evaluation Studies as Topic; Extracellular Fluid; Male; Metabolism; Monitoring, Physiologic; Neoplasms; Oxygen Consumption; Rats

Although we have reported that Toll-like receptor (TLR) 4 is involved in OK-432-induced anti-cancer immunity, its detailed mechanism remained uncertain. We hypothesized that OK-432 may first be captured, dissolved by phagocytes, and then active components released from the cells may stimulate TLR4. This hypothesis was examined by the current in vitro experiments. We used TS-2 MoAb which recognizes OK-PSA, an active component of OK-432. First, we observed that OK-432-induced cytokine production by dendritic cells (DCs) and macrophages was significantly inhibited by cytochalasin B, a phagocytosis inhibitor. Immunofluorescence staining by using TS-2 clearly demonstrated that OK-432 was captured and dissolved by these cells. OK-PSA was detected in the supernatants derived from OK-432-treated DC culture by ELISA with TS-2. The supernatants from OK-432-treated DC culture, but not from untreated DC culture, increased NF-kappaB activity in TLR4-expressing cells. The increased NF-kappaB activity was inhibited by TS-2. These findings elucidated the mechanism mediated by phagocytosis and TLR4 signaling in the OK-432 action.

Topics: Animals; Cytochalasin B; Dendritic Cells; Humans; In Vitro Techniques; Macrophages, Peritoneal; Membrane Glycoproteins; Mice; Neoplasms; Phagocytosis; Picibanil; Receptors, Cell Surface; Signal Transduction; Toll-Like Receptor 4; Toll-Like Receptors

Response of quiescent (Q) and total tumor cells in solid tumors to reactor neutron beam irradiation with two different cadmium (Cd) ratios was examined in terms of micronucleus (MN) frequency and apoptosis frequency, using four different tumor cell lines.. C57BL mice bearing EL4 tumors, C3H/He mice bearing SCC VII or FM3A tumors, and Balb/c mice bearing EMT6/KU tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. Thirty min after i.p. injection of sodium borocaptate-10B (BSH), or 3 h after oral administration of p-boronophenylalanine-10B (BPA), the tumors were irradiated with neutron beams. The tumors without 10B-compound administration were irradiated with neutron beams or gamma-rays. This neutron beam irradiation was performed using neutrons with two different Cd ratios. The tumors were then excised, minced, and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the MN frequency in cells without BrdU labeling (=Q cells) was determined using immunofluorescence staining for BrdU. Meanwhile, for apoptosis assay, 6 h after irradiation, tumor cell suspensions obtained in the same manner were fixed, and the apoptosis frequency in Q cells was also determined with immunofluorescence staining for BrdU. The MN and apoptosis frequencies in total (P + Q) tumor cells were determined from the tumors that were not pretreated with BrdU.. Without 10B-compounds, the sensitivity difference between total and Q cells was reduced by neutron beam irradiation. Under our particular neutron beam irradiation condition, relative biological effectiveness (RBE) of neutrons was larger in Q cells than in total cells, and the RBE values were larger for low Cd-ratio than high Cd-ratio neutrons. With 10B-compounds, both frequencies were increased for each cell population, especially for total cells. BPA increased both frequencies for total cells more than BSH did. Nevertheless, the sensitivity of Q cells treated with BPA was lower than that of Q cells treated with BSH. Whether based on the MN frequency or the apoptosis frequency, similar results concerning the sensitivity difference between total and Q cells, the values of RBE, and the enhancement effect by the use of 10B-compound were obtained.. Apoptosis frequency, as well as the MN frequency, can be applied to our method for measuring the Q cell response to reactor neutron beam irradiation within solid tumor in which the ratio of apoptosis to total cell death is relatively high, as in EL4 tumor. The absolute radiation dose required to achieve the same endpoint for Q cells is much higher than that for total cells when combined with 10B-compound, especially with BPA.

Topics: Animals; Apoptosis; Borohydrides; Boron Compounds; Boron Neutron Capture Therapy; Bromodeoxyuridine; Cadmium; Carcinoma, Squamous Cell; Cytochalasin B; Fluorescent Antibody Technique; Lymphoma; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Micronucleus Tests; Neoplasms; Neutrons; Phenylalanine; Radiation Tolerance; Radiation-Sensitizing Agents; Radiobiology; Radioisotopes; Relative Biological Effectiveness; Sarcoma, Experimental; Sulfhydryl Compounds; Tumor Cells, Cultured

This study indicated that by adding cytochalasin B (6 micrograms/ml) at 24 h, the lymphocyte culture time for micronucleus (MN) assay could be shortened to 64 h. In both unirradiated and ex-vivo irradiated (2 Gy) lymphocytes from three populations, we found that the differences in MN yield obtained by our modified cytokinesis-blocked time frame and that recommended by Fenech and Morley (1985) were insignificant (P = 0.66-0.87). We believe that the shorter assay time may enhance the applicability of MN assay for the rapid assessment of ionizing radiation overexposures.

Topics: Analysis of Variance; Cells, Cultured; Cytochalasin B; Humans; Lymphocytes; Micronucleus Tests; Mutagens; Neoplasms

We established an in vitro cytokinesis-block micronucleus assay of human tumours for estimation of the proportion of cells undergoing mitosis (the dividing fraction, DF), the time for the number of nuclei to double and the radiosensitivity in terms of the micronucleus frequency, based on a concept described previously. Under certain conditions, the nuclear number doubling time (NNDT) was considered to represent the potential doubling time. Tumour specimens obtained at surgery were disaggregated into single-cell suspensions and were directly cultured in the presence of cytochalasin B with or without irradiation. At various intervals, the percentage of multinucleate cells (the plateau value represented the DF), the average number of nuclei per cell and the number of micronuclei in binucleate cells were determined. DF and NNDT values were obtained in 58 of the 73 tumours investigated, and the micronucleus frequency was obtained in 54 of these 58 tumours. The DF ranged from 4.1% to 71% and the NNDT ranged from 3.1 to 83 days. A DF > or = 20% was associated with a higher recurrence rate in patients undergoing curative operation. A correlation was found between the NNDT and the time to relapse in patients with recurrent disease. The average number of micronuclei per binucleate cell at 2 Gy of irradiation (after subtraction of the value at 0 Gy) ranged from 0.052 to 0.35. Tumours which produced more micronuclei after irradiation showed a better response to radiotherapy. This assay can be readily performed on human tumours and appears to have promise as a predictive assay for radiation therapy.

Topics: Adenocarcinoma; Brain Neoplasms; Carcinoma; Carcinoma, Squamous Cell; Carcinoma, Transitional Cell; Cell Division; Cell Nucleus; Cell Survival; Cytochalasin B; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Humans; Micronucleus Tests; Neoplasms; Predictive Value of Tests; Prognosis; Radiation Tolerance; Remission Induction; Sarcoma; Treatment Outcome; Tumor Cells, Cultured

The micronucleus (MN) test has been carefully characterized in four human tumour cell lines of widely differing radiosensitivity. Two radioresistant bladder carcinoma cell lines (MGH-U1 and RT112), one sensitive medulloblastoma cell line (D283MED) and a sensitive neuroblastoma cell line (HX142) were used. The number of MN per Gy of ionising radiation was 0.13 for HX142, 0.17 for D283MED, 0.21 for RT112 and 0.26 for MGH-U1. This does not rank the cell lines in the same order of radiosensitivity as clonogenic cell survival where the surviving fraction at 2 Gy (SF2) was 0.11 for HX142, 0.2 for D283MED, 0.62 for RT112 and 0.53 for MGH-U1. This discrepancy between MN formation and cell death leaves doubt as to the potential usefulness of the MN test as a rapid assay of radiosensitivity but it has potential implications for the mechanistic basis of radiosensitivity in these cells.

Topics: Cell Death; Cell Division; Cell Survival; Cytochalasin B; Humans; Medulloblastoma; Micronuclei, Chromosome-Defective; Neoplasms; Neuroblastoma; Radiation Tolerance; Tumor Cells, Cultured; Urinary Bladder Neoplasms

Ascorbate ions induced a polarization peak in the intracellular fluorescein fluorescence polarization spectra of asynchronous populations of a variety of cancer cell types from human and animal biopsy material or in cells grown in vivo and/or in vitro. The appearance of this polarization peak at 510 nm on excitation at 470 nm (P510 peak) indicates the transition of mitochondria from the condensed (active) into orthodox (resting) conformation. In contrast, no effects of ascorbate ions were observed in the polarization spectra of various normal cell lines. This apparent differential response seems to be caused by the effects of ascorbate ions on several steps of the altered energy metabolism in cancer cells. It appeared not to be due to a defective mechanism responsible for the conformational changes in the mitochondria. In YMDR cells resistant to the antitumor drug methylene-dimethanesulphonate (MDMS), HeLa cells pretreated with colcemid, and YMDS cells pretreated with cytochalasin B, the transition of mitochondria into orthodox conformation could not be induced by ascorbate ions. Thus, it is possible that tumors also pretreated with other drugs become resistant to growth inhibitory effects of ascorbate ions. Induction of the fluorescein emission polarization peak at 510 nm in cells from biopsies or from in vitro-induced malignancies could be used as an additional criterion for malignant transformation.

Topics: 2,4-Dinitrophenol; Ascorbic Acid; Calcium; Cell Line; Cyclic AMP; Cytochalasin B; Demecolcine; Dinitrophenols; Energy Metabolism; Fluorescence Polarization; Glycolysis; Humans; Hydrogen-Ion Concentration; Interphase; Methyl Methanesulfonate; Mitochondria; Neoplasms

Micronucleation was induced by vincristine, colcemid, and colcemid in combination with cytochalasin B in cells of a human metastatic breast carcinoma cell line (MDA MB 231). Cells treated with the latter combination were enucleated subsequently by centrifugation in the presence of cytochalasin B. The resulting "microcell" fraction was fused with mitotic human primary fibroblasts or mitotic HeLa cells using polyethyleneglycol (PEG). The success of the microcell-mediated chromosome transfer thus could be demonstrated as premature condensation in the mitotic recipient of the transferred micronuclei. This technique of cytogenetic analysis allowed a fast and simple control of the influence of different conditions on micronucleation and fusion of micronuclei with recipient cells. It could be shown that microcell-mediated chromosome transfer from human tumor cells into human normal, as well as human tumor, recipient cells is practicable if the techniques figured out by the present study are employed.

Topics: Breast Neoplasms; Cell Fusion; Cell Line; Cell Nucleus; Chromosomes, Human; Cytochalasin B; Demecolcine; Female; Genetic Engineering; Genetic Vectors; HeLa Cells; Humans; Neoplasms; Polyethylene Glycols; Vincristine

Human tumor cell lines derived from melanoma, glioblastoma, and carcinoma of the prostate, bladder, and kidney multinucleated in response to growth in cytochalasin B-supplemented medium, whereas cell lines derived from normal prostate, kidney, skin, lung, and other nonmalignant diseases remained predominantly binucleate under comparable conditions. The multinucleate cytochalasin B phenotype was dissociable from the anchorage-independent phenotype of tumor cells, suggesting that these markers of cellular transformation are under separate control. These results suggest that uncontrolled nuclear division by tumor cells may be a general marker of abnormal growth or regulation.

Topics: Cell Line; Cell Nucleus; Cytochalasin B; Glioma; Humans; Male; Melanoma; Neoplasms; Prostate; Prostatic Hyperplasia; Prostatic Neoplasms; Urinary Bladder Neoplasms

Twelve human cell cultures derived from tumors, normal tissues, and derivative cultures transformed by either a RNA tumor virus or chemical carcinogen were examined for their response to cytochalasin B (CB) and the expression of this marker was correlated with growth in soft agar and saturation density in monolayer culture. Cell lines derived from carcinoma of the bladder (T24 and RT4), kidney (Caki-1), prostate (DU 145), and breast (MCF-7) multinucleated when growth in CB-supplemented medium, whereas cell cultures derived from benign bladder epithelium (HCV-29), and normal kidney (Flow 4000) and skin (GM10) remained binucleate under comparable conditions. Human osteosarcoma (HOS) cells transformed by murine sarcoma virus (MSV) or a chemical carcinogen extensively multinucleated in response to CB treatment, relative to a morphological revertant of MSV-transformed HOS and parental HOS cells. CB-induced multinucleation was consistently correlated with the ability of cells to form colonies in soft agar but inconsistently correlated with growth to high saturation densities. These results demonstrate a differential response to CB by normal and transformed human cells and that CB-induced multinucleation provides a convenient and useful in vitro marker for neoplastic transformation.

Topics: Cell Division; Cell Line; Cell Transformation, Neoplastic; Clone Cells; Contact Inhibition; Cytochalasin B; Humans; Mitosis; Neoplasms

Topics: Cell Nucleus; Cell Transformation, Neoplastic; Cells, Cultured; Cytochalasin B; Humans; Neoplasms

When motile cells are incubated with Forssman glycolipid, the antigen is incorporated into the cells' plasma membranes. If cross-linked by antibody, the patched glycolipids cap. This process is sensitive to those drugs that are known to inhibit capping of protein antigens. The results support a flow mechanism for capping.

Topics: Animals; Cell Line; Cell Membrane; Colchicine; Cytochalasin B; Dinitrophenols; Fluorescent Antibody Technique; Forssman Antigen; Glycolipids; Immunologic Capping; Mice; Neoplasms; T-Lymphocytes

Topics: Adult; Aged; Blood Bactericidal Activity; Carcinoma; Cytochalasin B; Female; Humans; Iodoacetates; Lymphoma; Male; Middle Aged; Monocytes; Neoplasms; Staphylococcus; Tuberculosis

Topics: Animals; Colchicine; Cyclic AMP; Cycloheximide; Cytochalasin B; Edetic Acid; Emetine; Immunity, Cellular; Immunization; Mast-Cell Sarcoma; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Neoplasms; Neoplasms, Experimental; Spleen; T-Lymphocytes