Showing papers on "Cell culture published in 1969"
TL;DR: An understanding of how normal cells and normal animals prevent expression of endogenous viral information would appear to offer one of the best hopes for the control of naturally occurring cancers.
Abstract: Evidence from sero-epidemiological studies and from cell culture studies supports the hypothesis that the cells of many, and perhaps all, vertebrates contain information for producing C-type RNA viruses. It is postulated that the viral information (the virogene), including that portion responsible for transforming a normal cell into a tumor cell (the oncogene), is most commonly transmitted from animal to progeny animal and from cell to progeny cell in a covert form. Carcinogens, irradiation, and the normal aging process all favor the partial or complete activation of these genes. An understanding of how normal cells and normal animals prevent expression of endogenous viral information would appear to offer one of the best hopes for the control of naturally occurring cancers.
799 citations
TL;DR: A continuous cell line of highly contact-inhibited cells (NIH/3T3) has been developed from NIH Swiss mouse embryo cultures and its growth properties are similar to those of 3T3 and BALB/3 T3.
Abstract: A continuous cell line of highly contact-inhibited cells (NIH/3T3) has been developed from NIH Swiss mouse embryo cultures. Its growth properties are similar to those of 3T3 and BALB/3T3. Although 3T3 is relatively insensitive to focus formation by murine sarcoma viruses, cloned lines of both NIH/3T3 and BALB/3T3 have been isolated that are highly sensitive to sarcoma virus focus formation and leukemia virus growth. The sensitivity and specificity are comparable to those found with primary embryo cells. MSV-transformed lines of NIH/3T3 have been obtained.
755 citations
TL;DR: Radioactive RNA introduced into “target” cells can be induced to form hybrids with nuclear DNA and the location of these hybrids can be detected by autoradiography.
Abstract: Radioactive RNA introduced into “target” cells can be induced to form hybrids with nuclear DNA. The location of these hybrids can be detected by autoradiography.
619 citations
TL;DR: Several tissue culture cell lines that were transformed by a tumor virus have been found to react with an agglutinin, while under identical conditions their untransformed parent cell lines did notagglutinate.
Abstract: Several tissue culture cell lines that were transformed by a tumor virus have been found to react with an agglutinin, while under identical conditions their untransformed parent cell lines did not agglutinate. Since a short treatment of the parent cell line with low concentrations of proteases exposed the same agglutinin receptor sites in a fashion indistinguishable from the transformed cells, it is proposed that both viral and chemical transformation produce changes in the architecture of the membrane, identical to those of the proteases.
512 citations
TL;DR: Results indicate that the surface membrane of transformed cells contains sites that interact with the alpha-MG binding sites of ConA, that such sites can be found on the surface membranes of normal cells after treatment with trypsin, and that the change in the surface structure from normal to transformed occurs in cells that are abortively transformed.
Abstract: It has been shown that the carbohydrate-binding protein concanavalin A (ConA) can agglutinate leukemic cells and cells transformed by polyoma virus, simian virus 40, chemical carcinogens, and X-irradiation. This protein did not agglutinate normal cells under the same conditions. The agglutination was reversed by competition with α-methyl-D-glucopyranoside (α-MG), a carbohydrate that strongly binds to ConA, but not by the carbohydrates α-methyl-L-fucopyranoside or N-acetylglucosamine, with no binding or weak binding to ConA. Destruction of the α-MG binding sites of the native protein by removal of bivalent metal ions abolished the agglutination produced by the native protein. The treatment of cells with trypsin resulted in the agglutination of normal cells by ConA and a decrease of agglutinability of transformed cells. When nonagglutinating untransformed 3T3 cells were infected with simian virus 40 and normal rat cells were infected with polyoma virus, the infected cells became agglutinable several days after virus infection. The percentage of cells agglutinated, about 50 per cent, was much higher than the percentage of cells hereditarily transformed. The results indicate that the surface membrane of transformed cells contains sites that interact with the α-MG binding sites of ConA, that such sites can be found on the surface membrane of normal cells after treatment with trypsin, and that the change in the surface structure from normal to transformed occurs in cells that are abortively transformed.
486 citations
TL;DR: A cell line established in vitro from a spontaneous myeloid leukemia of SL strain mice was cytologically identified as myeloblast, and its normal differentiation appeared to be completely blocked in mass culture.
Abstract: A cell line was established in vitro from a spontaneous myeloid leukemia of SL strain mice. This cell line was cytologically identified as myeloblast, and its normal differentiation appeared to be completely blocked in mass culture. When the line cells were seeded in soft agar with a conditioned medium from normal cells, either macrophages or neutrophil granulocytes appeared from a single clone. The rate of formation of colonies containing differentiated cells always increased with an increase in the concentration of conditioned medium. The conditioned medium from this line cell was not as effective as was that from normal cells in inducing differentiation.
482 citations
TL;DR: A striking morphological change was observed in the cells adapted to culture growth; they appeared as mature neurons, while the cells of the tumor appeared as immature neuroblasts.
Abstract: Clonal lines of neurons were obtained in culture from a mouse neuroblastoma. The neuroblastoma cells were adapted to culture growth by the animal-culture alternate passage technique and cloned after single-cell plating. The clonal lines retained the ability to form tumors when injected back into mice. A striking morphological change was observed in the cells adapted to culture growth; they appeared as mature neurons, while the cells of the tumor appeared as immature neuroblasts.
Acetylcholinesterase and the enzymes for the synthesis of neurotransmitters, cholineacetylase and tyrosine hydroxylase were assayed in the tumor and compared with brain levels; tyrosine hydroxylase was found to be particularly high, as described previously in human neuroblastomas. The three enzymes were found in the clonal cultures at levels comparable to those found in the tumors. Similarly, there were no remarkable differences between the three clones examined.
461 citations
TL;DR: Aryl hydrocarbon hydroxylase from rat liver metabolizes a variety of polycyclic hydrocarbons and is inducible in fetal cell cultures derived from whole hamster, mouse, rat, and chick.
422 citations
TL;DR: Mouse bone marrow cells in suspension were separated into a number of fractions on the basis of cell density by equilibrium density gradient centrifugation, or on the based of cell size by velocity sedimentation, to demonstrate that cells in some fractions formed more colonies in vivo than in the culture system.
Abstract: Mouse bone marrow cells in suspension were separated into a number of fractions on the basis of cell density by equilibrium density gradient centrifugation, or on the basis of cell size by velocity sedimentation. After each type of separation, the cells from the various fractions were assayed for their ability to form macroscopic spleen colonies in irradiated recipient mice, and for their ability to form colonies in a cell culture system. The results from either separation technique demonstrate that cells in some fractions formed more colonies in vivo than in the culture system, while cells in other fractions formed more colonies in culture than in the spleen. The results of control experiments indicate that this separation of the two types of colony-forming cells was not an artifact of the separation procedures. From these experiments it was concluded that the population of cells which form colonies in culture under the conditions used is not identical to the population of cells detected by the spleen colony assay.
405 citations
TL;DR: Two cell lines were derived from an embryonal rhabdomyosarcoma and each line consisted of 2 cytologic types resembling those of the original tumor—spindle cells and large multinucleated cells.
Abstract: Two cell lines were derived from an embryonal rhabdomyosarcoma. Cells of both lines grew as monolayers in liquid medium and formed colonies in agar medium. Each line consisted of 2 cytologic types resembling those of the original tumor—spindle cells and large multinucleated cells. No myofibrils could be demonstrated in the cells by light or by electron microscopy nor were virus particles detected. Cells of both lines probably contained myosin-ATPase and cells of line #2 contained myoglobin. Chromosome studies of cell line #1 revealed a stem-line of 51 chromosomes with a consistent karyotype. Three passages of cell line #2 were studied, and no evidence of a stem-line was noted. Chromosome counts ranged from 45 to 170, and consistent marker chromosomes in most cells were present in the form of large metacentrics in the C group.
302 citations
TL;DR: Mouse tumor C1300 has been established in tissue culture and cell attachment can induce morphological differentiation from an anaplastic round cell to a cell which has many properties of a mature neuron.
Abstract: Mouse tumor C1300 has been established in tissue culture. The cells have a round cell morphology in both the subcutaneous tumor and in suspension culture. However, when given a surface on which to attach, they send out processes up to 3 mm in length and assume the morphology of mature neurons. The attached cells are stained by the Bodian silver procedure for neurons, whereas the cells grown in suspension are not. Electron microscopy reveals that the attached cells contain neurofilaments, neurotubules, and densecore vesicles indicative of nerve fibers. Both free-floating and attached cells have tyrosine hydroxylase activity characteristic of sympathetic nervous tissue. Apparently cell attachment can induce morphological differentiation from an anaplastic round cell to a cell which has many properties of a mature neuron.
TL;DR: Cells of a genetic variant of the hamster fibroblast line BHK 21 which lack inosinic pyrophosphorylase activity ( IPP - cells) and therefore cannot normally incorporate [ 3 H]hypoxanthine were grown in mixed culture.
Abstract: Cells of a genetic variant of the hamster fibroblast line BHK 21 which lack inosinic pyrophosphorylase activity ( IPP - cells) and therefore cannot normally incorporate [ 3 H]hypoxanthine were grown in mixed culture with cells of BHK 21 sublines which have inosinic pyrophosphorylase activity ( IPP + cells). If not in contact with IPP + cells, IPP - cells do not incorporate added [ 3 H]hypoxanthine into nucleic acid. IPP + cells always do incorporate [ 3 H]hypoxanthine and IPP - cells when in direct or indirect contact with IPP + cells also incorporate the isotope. Cell to cell contact appears to be essential for this gain of a metabolic function by IPP - cells. The possible molecular basis and general implications of the phenomenon are discussed.
TL;DR: Tissue culture cells of a Rous virus-induced rat tumor undergo syncytium formation when placed in contact with mouse embryo cell cultures infected with murine leukemia viruses, which can be used as a cytopathic end point for isolating and titrating these viruses in tissue culture.
Abstract: Tissue culture cells of a Rous virus-induced rat tumor undergo syncytium formation when placed in contact with mouse embryo cell cultures infected with murine leukemia viruses. This phenomenon can be used as a cytopathic end point for isolating and titrating these viruses in tissue culture. The principle should be applicable to detection of leukemia viruses of other species.
TL;DR: After irradiation in the plateau phase of growth, not only do these human cells recover from sub-lethal radiation damage, but potentially lethal damage is repaired if the cells are allowed to remain in the stationary phase for some time after irradiation.
Abstract: WHEN monolayer cultures of mammalian cells are allowed to reach the stationary or plateau phase of growth, overall DNA synthesis decreases markedly. This is chiefly a result of the appearance of many non-proliferating cells which remain in the presynthetic (G1) stage of the cell cycle, while the cell concentration remains approximately constant because the lowered rate of cell division is balanced by the sloughing of dead cells into the nutrient medium1,2. Such cultures are interesting to radiobiologists because they represent an in vitro cell renewal system which has several of the characteristics of human malignant tumours. When Chinese hamster cells were irradiated in the plateau phase of growth, the slope of the survival curve was similar to that obtained with exponentially growing cultures, but the cells did not accumulate and repair sub-lethal damage3. I have investigated the effects of radiation on stationary cultures of a line of cells derived from normal human liver (Chang)4. After irradiation in the plateau phase of growth, not only do these human cells recover from sub-lethal radiation damage, but potentially lethal damage is repaired if the cells are allowed to remain in the stationary phase for some time after irradiation.
TL;DR: Adenovirus type 12 infects baby hamster kidney cells (BHK21), but does not multiply in these cells, and replication of Ad 12 DNA cannot be detected by equilibrium sedimentation in CsCl density gradients or by DNA-DNA hybridization on membrane filters.
TL;DR: This chapter reviews a series of experiments that utilize muscle cell cultures as a model for studying some of the inherent properties of differentiating cells and shows that the changes, which take place in the growth characteristics during establishment of cell lines, may be distinct from the differentiation characteristics of these lines.
Abstract: Publisher Summary This chapter reviews a series of experiments that utilize muscle cell cultures as a model for studying some of the inherent properties of differentiating cells. A main outcome of the experiments is the establishment of myogenic cell lines that are able to multiply for extended periods in culture and retain their capacity to differentiate. It is not clear why some of the attempts to establish myogenic lines resulted in the loss of the cells by degeneration and cessation of multiplication whereas others were successful. This experience is common for many kinds of mammalian or avian cells serially passaged in vitro. The establishment of myogenic cell lines is of special interest with relevance to this phenomenon as it shows that the changes, which take place in the growth characteristics during establishment of cell lines, may be distinct from the differentiation characteristics of these lines. The possibility of cloning and thus performing analyses and experiments on homogeneous populations of one kind of cell makes this system valuable and versatile for studying many aspects of cell differentiation. Differentiated primary cultures always contain a population of mononucleated cells that do not participate in fusion. The relative proportion between the amount of mononucleated and multinucleated cells is variable and is influenced by culture conditions. Also, under identical culture conditions, clones produced by different cell lines differ considerably in their mononucleated cell content.
TL;DR: This cell culture system should be useful in studying the inheritance of the diabetic gene(s), the pathogenesis of the diabetes state, and the relationship between aging and diabetes, both of which decrease plating efficiency.
Abstract: This work concerns the effect of age and the diabetic gene(s) on the growth capacity of skin fibroblasts in culture. Cells from normal subjects and the progeny of conjugal diabetics have similar lifespans after multiple passages in mass culture. The combined lifespans in vitro are inversely proportional to the age of the donor. When individual cells are plated, more of those from normal subjects are able to form colonies. The difference in plating efficiency is apparent when first tested after 20 generations of growth, persists at 30 and 40 generations, but disappears after 50 generations. This cell culture system should be useful in studying the inheritance of the diabetic gene(s), the pathogenesis of the diabetic state, and the relationship between aging and diabetes, both of which decrease plating efficiency.
TL;DR: The idea that chromosome damage may not be the major cause of cell killing is suggested by the observations that frequency of first division lethal sectoring showed no age dependence and multipolar mitosis appeared to account for a significant proportion of non-surviving clones at low doses.
Abstract: SummaryProliferation kinetics of x-irradiated mouse L-P59 fibroblasts were studied by constructing cell pedigrees from photographic records. Parameters of proliferation showed marked age dependence; early G1 cells were most resistant and late S-G2 cells were most sensitive in terms of reduction in probability of division, increase in generation time, and induction of abnormal mitotic figures (multipolar and incomplete mitoses). Division probabilities were higher at first division than at subsequent divisions, and cell death in some pedigrees was absent until the fourth generation or later. Prolongation in generation time occurred during several post-irradiation divisions, most noticeably in abortive clones. The idea that chromosome damage may not be the major cause of cell killing is suggested by the observations that (1) frequency of first division lethal sectoring showed no age dependence; (2) multipolar mitosis appeared to account for a significant proportion of non-surviving clones at low doses.
TL;DR: Mouse interferon preparations derived from three different tissue sources- brain, serum, and monolayer cell cultures-all proved effective and it is suggested that Interferon itself (or a factor closely associated withinterferon) is the active moiety in these preparations.
Abstract: Repeated administration of potent mouse interferon preparations increased the survival of Balb/c and C 57/B1(6) mice inoculated with 2,000-3,000 RC(19) and EL(4) tumor cells. Only 7/188 (3.7%) untreated mice (or mice treated with control preparations) survived more than 22 days after intraperitoneal inoculation of RC(19) tumor cells. None survived more than 60 days. In contrast, 101/103 (98%) interferon-treated mice survived beyond 22 days, and sixteen (15%) survived more than 60 days. None of these 16 surviving mice show any sign of tumor at present. Three mice (of the 16) from an early experiment are alive ten months after inoculation of RC(19) tumor cells. Mouse interferon preparations derived from three different tissue sources- brain, serum, and monolayer cell cultures (with Newcastle disease virus and West Nile virus as interferon-inducing agents)-all proved effective. A purified preparation of mouse brain interferon was as effective as crude brain interferon. Human amniotic membrane interferon and control tissue preparations were without effect. These findings suggest that interferon itself (or a factor closely associated with interferon) is the active moiety in these preparations.
TL;DR: A transplantable tumor of inbred mice was obtained by inoculating BALB/c mice subcutaneously with SV40‐transformed mouse kidney (mKS‐A) cells, and sera from the tumor‐bearing mice contained antibodies to the SV40 T‐antigen.
Abstract: A transplantable tumor of inbred mice was obtained by inoculating BALB/c mice subcutaneously with SV40-transformed mouse kidney (mKS-A) cells. Tumors were produced by mKS-A cells in the 71st cell culture passage, but not by cells in the 26th passage. The tumor line has been serially passed in BALB/c mice 14 times. In vitro cell culture lines were derived from tumors after 1, 2, 8, 10 and 12 passages in mice. The tumors, as well as the In vitro tumor cell lines, contained SV40 T-antigen, and sera from the tumor-bearing mice contained antibodies to the SV40 T-antigen. SV40 was rescued from the In vitro tumor cell lines after fusion with green monkey kidney (CV-1) cells in the presence of UV-irradiated Sendai virus.
The In vitro tumor cell lines derived from mouse passages 8, 10 and 12 were used as SV40 virus; 2) SV40-transformed cell lines; 3) primary mouse (BALB/c or Yale Swiss) kidney cells, or 4) primary mouse (BALB/c or Yale Swiss) embryo cells. These results showed that the tumor line and the In vitro tumor cell lines have the transplantation antigen.
TL;DR: Mouse spleen cells were found to associate in cell clusters during the primary immune response to sheep erythrocytes in vitro, and the integrity of cell clusters was required for the proliferation of antibody-forming cells, and prevention of clusters by mechanical means or by excess antibody blocked the immune response.
Abstract: Mouse spleen cells were found to associate in cell clusters during the primary immune response to sheep erythrocytes in vitro. About 10% of the cell clusters had the following unique properties; (a) they contained most, if not all, antibody-forming cells, (b) they contained only cells forming antibody to one antigen when cell cultures were immunized with two antigens, (c) the cells in clusters reaggregated specifically after dispersion, and (d) the specific reaggregation of clusters appeared to be blocked by antibody to the antigen. The integrity of cell clusters was required for the proliferation of antibody-forming cells, and prevention of clustering by mechanical means or by excess antibody blocked the immune response. Antibody and antigenic determinants on the surfaces of cells probably provide the basis for interaction. The unique microenvironment of cell clusters was essential for the primary immune response in vitro.
TL;DR: The results indicate that transcription of immunoglobulin genes takes place during a limited part of the mitotic cycle.
Abstract: In synchronized human lymphoid cell lines, production of immunoglobulins G and M is greatest during the late Gl and S phases of the cell cycle. Little immunoglobulin appears immediately before, during, and immediately after mitosis. The results indicate that transcription of immunoglobulin genes takes place during a limited part of the mitotic cycle.
TL;DR: The evidence presented here demonstrates that the murine leukemia virus genome must be present in the original embryo cultures, and the possibility that the genetic information for making murines leukemia virus is present in a repressed form in every mouse embryo cell is discussed.
Abstract: BALB/c mouse embryo cells maintained in tissue culture on a schedule of rapid transfer at high cell density develop into tumorigenic lines that have lost contact inhibition of cell division. After several months in culture, certain of these lines begin to release mouse leukemia virus. This virus has properties indistinguishable from those of virus found in adult BALB/c mice. The evidence presented here demonstrates that the murine leukemia virus genome must be present in the original embryo cultures. The possibility that the genetic information for making murine leukemia virus is present in a repressed form in every mouse embryo cell is discussed.
TL;DR: Mouse leukemic cells (L5178Y) in suspension culture were irradiated and the extent of single-strand breaks and double-Strand cuts of DNA was estimated by sucrose gradient centrifugation.
TL;DR: The interaction of (32)P-labeled adenovirus type 2 and HeLa or KB cells has been examined during early infection and the kinetics of virus uncoating to deoxyribonuclease-sensitive products, the partial characterization by gradient centrifugation, and the distribution of these products in the extranuclear and nuclear portions of infected cells are reported.
Abstract: The interaction of (32)P-labeled adenovirus type 2 and HeLa or KB cells has been examined during early infection. The kinetics of virus uncoating to deoxyribonuclease-sensitive products, the partial characterization of three such products by gradient centrifugation, and the distribution of these products in the extranuclear and nuclear portions of infected cells are reported. The results are compatible with the following model. Extracellular virus attaches to a receptor on the plasma membrane. The membrane-bound virus has a half-life of less than 15 min and is transformed to a partly uncoated product which is free inside the cell and about half of which rapidly enters the cell nucleus. This is rapidly transformed, in both cytoplasm and nucleus, to a membrane-bound virion "core." The proteins of the bound "core" are then removed from the intact virus deoxyribonucleic acid (DNA). In the nucleus, viral DNA is the main product and there the overall sequence is completed in about 2 hr.
TL;DR: For example, the authors showed that normal and transformed hamster embryo fibroblasts, which communicate when cultured in medium containing fetal calf serum, appear to lose communication when cultured with medium containing calf serum.
Abstract: Epithelial cells of normal rat (adult) liver and hamster embryo in tissue culture communicate through membrane junctions: the membrane regions of cell contact are highly ion-permeable. Cancerous counterparts of these cells, cells from Morris' and Reuber's liver tumors and from x-ray-transformed embryo cultures, do not communicate under the same experimental conditions. These cells also fail to communicate with contiguous normal cells. Cancerous fibroblastic cells from a variety of tissues, including cells transformed by virus, x-radiation and chemicals, communicate as well as their normal counterparts; this is so for long- and short-term cell cultures. Communication in some fibroblastic cells is sensitive to components of blood serum: normal and transformed hamster embryo fibroblasts, which communicate when cultured in medium containing fetal calf serum, appear to lose communication in medium containing calf serum; the converse holds for hamster (adult) fibroblasts and 3T3 cells.
TL;DR: The unusual cellular trait—IgM specificity—being present on both the biopsy and its derived cell line, indicates the representativeness of the culture line for the in‐vivo tumor in this case.
Abstract: Thirty-five cell lines were established from 47 Burkitt lymphoma biopsies. In different biopsies the modal cell size was found to vary and the tumor was often built up by larger cells if the patients received chemotherapy. In all cases the predominant cell size shifted towards larger values during cultivation. All cells in three biopsies from one patient and in the culture lines derived showed surface reactivity with anti-IgM and antikappa light chain reagents. This trait was maintained in all three lines for about 21 weeks but was lost thereafter. A fourth biopsy—taken after the patient had been treated with cytosine arabinoside—did not have this immunoglobulin reactivity. Chromosomal analysis revealed that one of the IgM reactive lines had 46 as stemline number and normal diploid karyotype, while the nonreactive line had 47 as stemline number with an extra C chromosome in addition to the normal male karyotype. One or two C chromosomes, corresponding in size with pair 10 were formed as markers with subterminal constriction on their long arms. The unusual cellular trait—IgM specificity—being present on both the biopsy and its derived cell line, indicates the representativeness of the culture line for the in-vivo tumor in this case.
TL;DR: In mouse cell lines transformed by SV40 virus, a decrease was observed in the higher ganglioside homologues disialo-ceramidetetrahexoside and monosialo, which indicates that the change is one of the virus-regulated functions, and it is postulated that it relates to the rejection of theirus-transformed cells.
Abstract: In mouse cell lines transformed by SV40 virus, a decrease was observed in the higher ganglioside homologues disialo-ceramidetetrahexoside and monosialo-ceramidetetrahexoside. Such change was observed only in cells which carry the virus genome, and it correlated with increased saturation density in tissue culture and with rejection in immunologically competent syngeneic host. This indicates that the change is one of the virus-regulated functions, and it is postulated that it relates to the rejection of the virus-transformed cells.
TL;DR: The kinetics of repair suggest that, during the repair process, a transient, unstable cellular state occurs which prevents cell division in complete growth medium, and the capacity for repair appears to be dependent on cell age.
Abstract: Less than optimum conditions with regard to cell division after x-irradiation provide the necessary environment in which mammalian cells can repair potentially lethal radiation damage. The kinetics of repair suggest that, during the repair process, a transient, unstable cellular state occurs which prevents cell division in complete growth medium. The capacity for repair appears to be dependent on cell age.