scholarly journals CONTACT-INHIBITED REVERTANT CELL LINES ISOLATED FROM SV40-TRANSFORMED CELLS

1971 ◽  
Vol 50 (3) ◽  
pp. 691-708 ◽  
Author(s):  
N. Scott McNutt ◽  
Lloyd A. Culp ◽  
Paul H. Black
Keyword(s):  
Cell Lines ◽  
Culture Conditions ◽  
Contact Inhibition ◽  
3T3 Cells ◽  
Nuclear Pleomorphism ◽  
Inhibition Of Growth ◽  
Cell Processes ◽  
In Situ Embedding ◽  
Peripheral Cytoplasm

The ultrastructural appearances of normal 3T3, SV40-transformed 3T3 (SV-3T3), and F1A revertant cell lines are compared. Both confluent and subconfluent cultures are described after in situ embedding of the cells for electron microscopy. There is striking nuclear pleomorphism in F1A revertant cells, with many cells having large nuclei compared to the less variable nuclear morphology of both normal 3T3 and SV-3T3 cells. Under the culture conditions used, deep infoldings of the nuclear envelope are prominent in growing cells, e.g., subconfluent normal 3T3 and confluent SV-3T3 cells. Such infoldings are infrequently seen in cultures which display contact inhibition of growth, e.g., normal 3T3 or F1A revertant cells grown just to confluence. In confluent cultures, the cytoplasmic organelles in revertant cells closely resemble those of normal 3T3 cells. In both normal and revertant cells in confluent culture, the peripheral cytoplasm (ectoplasm) has many 70 A filaments (alpha filaments), which are frequently aggregated into bundles. Alpha filaments are also abundant in the ectoplasm near regions of cell-to-cell apposition and in the motile cell processes (filopodia). The abundance and state of aggregation of alpha filaments correlates with contact inhibition of movement and growth in these cell lines since fewer bundles of alpha filaments are seen in growing cells than in contact-inhibited cells. This observation suggests that these filaments may be an important secondary component in the regulation of contact inhibition of movement and, possibly, of growth in normal and revertant cells.

The Effect of Cell Population Density on Nutrient Uptake and Cell Metabolism: a Comparative Study of Human Diploid and Heteroploid Cell Lines

1972 ◽  
Vol 10 (2) ◽  
pp. 515-524
Author(s):  
J. B. GRIFFITHS
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Dna Synthesis ◽  
Nutrient Uptake ◽  
Cell Lines ◽  
Acid Concentration ◽  
Contact Inhibition ◽  
Inhibition Of Growth ◽  
Extracellular Amino Acid

The possibility that contact inhibition of growth in cultures of human diploid cells is influenced by the effects of cell crowding on nutrient uptake by the cells was investigated. Two human lung cell lines were compared, the diploid line MRC-5 and the heteroploid line L-132. In pre-confluent cultures the ability of these 2 cell types to accumulate amino acids was very similar. Post-confluent L-132 cells showed very little change from the pre-confluent cultures but the ability of MRC-5 cells in post-confluent cultures was greatly reduced. The intracellular concentrations of various amino acids necessary to achieve the maximum rate of protein synthesis were found. These values were identical for sparse and crowded cultures but due to the reduced uptake ability of crowded MRC-5 cells a far higher external amino acid concentration was required in post-confluent cultures. This meant that although amino acids did not become growth-limiting until over 80% utilized in pre-confluent cultures, in post-confluent cultures they became growth-limiting when only 50% utilized. Although protein synthesis was significantly affected by extracellular amino acid concentration and cell crowding, thus contributing towards the effect of contact inhibition of growth, DNA synthesis was shown to be the major metabolic function in contact inhibition. Increased cell density had a very inhibitory effect on DNA synthesis in MRC-5 cultures, but not in L-132 cultures, and this was unaffected by extracellular amino acid and glucose concentration.

scholarly journals Propagation of Arthropod-Borne Rickettsia spp. in Two Mosquito Cell Lines

2007 ◽  
Vol 73 (20) ◽  
pp. 6637-6643 ◽  
Author(s):  
Joyce M. Sakamoto ◽  
Abdu F. Azad
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Spotted Fever ◽  
Culture Conditions ◽  
Spotted Fever Group ◽  
Rickettsia Felis ◽  
Transitional Group ◽  
Mosquito Cell Lines

ABSTRACT Rickettsiae are obligate intracellular alphaproteobacteria that include pathogenic species in the spotted fever, typhus, and transitional groups. The development of a standardized cell line in which diverse rickettsiae can be grown and compared would be highly advantageous to investigate the differences among and between pathogenic and nonpathogenic species of rickettsiae. Although several rickettsial species have been grown in tick cells, tick cells are more difficult to maintain and they grow more slowly than insect cells. Rickettsia-permissive arthropod cell lines that can be passaged rapidly are highly desirable for studies on arthropod-Rickettsia interactions. We used two cell lines (Aedes albopictus cell line Aa23 and Anopheles gambiae cell line Sua5B) that have not been used previously for the purpose of rickettsial propagation. We optimized the culture conditions to propagate one transitional-group rickettsial species (Rickettsia felis) and two spotted-fever-group rickettsial species (R. montanensis and R. peacockii) in each cell line. Both cell lines allowed the stable propagation of rickettsiae by weekly passaging regimens. Stable infections were confirmed by PCR, restriction digestion of rompA, sequencing, and the direct observation of bacteria by fluorescence in situ hybridization. These cell lines not only supported rickettsial growth but were also permissive toward the most fastidious species of the three, R. peacockii. The permissive nature of these cell lines suggests that they may potentially be used to isolate novel rickettsiae or other intracellular bacteria. Our results have important implications for the in vitro maintenance of uncultured rickettsiae, as well as providing insights into Rickettsia-arthropod interactions.

scholarly journals CONTACT-INHIBITED REVERTANT CELL LINES ISOLATED FROM SV40-TRANSFORMED CELLS

1973 ◽  
Vol 56 (2) ◽  
pp. 412-428 ◽  
Author(s):  
N. Scott McNutt ◽  
Lloyd A. Culp ◽  
Paul H. Black
Keyword(s):  
Cell Lines ◽  
Transformed Cells ◽  
Cell Periphery ◽  
3T3 Cells ◽  
Heavy Meromyosin ◽  
Thin Sections ◽  
Transformed Cell Line ◽  
Close Relationship ◽  
Loss Of Contact

A comparison is made of the ultrastructure of the cell periphery in three cloned cell lines: untransformed Balb/c 3T3 cells, SV40-transformed Balb/c 3T3 cells, and revertant cells obtained from the transformed cell line by a selection technique utilizing concanavalin A. Both thin-section and surface replication techniques are used for in situ examination of the cell lines. Microfilaments, 70 Å in diameter (called alpha filaments), are abundant in untransformed and revertant cell lines, particularly in the anterior expansions of the cells, which tend to have many microvilli and small pseudopodia. Alpha filaments are diminished in the anterior expansions of transformed cells, which contain large blunt pseudopodia and relatively few microvilli. Surface replicas confirm the impression gained from thin sections that transformed cells have a greater proportion of their cell surface involved in bulging pseudopodia than either untransformed or revertant cells. Since alpha filaments are shown to bind heavy meromyosin and are similar to F-actin, these filaments are thought to be important in cell motility. These observations suggest that a close relationship exists between decreased alpha filaments, bulging pseudopodia, and loss of contact inhibition of movement in transformed cells.

Lectin Binding Studies on RNA Tumor Virus-Infected Cells

1975 ◽  
Vol 33 ◽  
pp. 326-327
Author(s):  
D. C. Hixson
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Culture Conditions ◽  
3T3 Cells ◽  
Binding Studies ◽  
Con A ◽  
Microscopic Studies ◽  
Tumor Virus ◽  
Infected Cells ◽  
Cell Culture Conditions

The abilities of plant lectins to preferentially agglutinate malignant cells and to bind to specific monosaccharide or oligosaccharide sequences of glycoproteins and glycolipids make them a new and important biochemical probe for investigating alterations in plasma membrane structure which may result from malignant transformation. Electron and light microscopic studies have demonstrated clustered binding sites on surfaces of SV40-infected or tryp- sinized 3T3 cells when labeled with concanavalin A (con A). No clustering of con A binding sites was observed in normal 3T3 cells. It has been proposed that topological rearrangement of lectin binding sites into clusters enables con A to agglutinate SV40-infected or trypsinized 3T3 cells (1). However, observations by other investigators have not been consistent with this proposal (2) perhaps due to differences in reagents used, cell culture conditions, or labeling techniques. The present work was undertaken to study the lectin binding properties of normal and RNA tumor virus-infected cells and their associated viruses using lectins and ferritin-conjugated lectins of five different specificities.

Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives of Benzimidazole as Potential Anti-Breast Cancer (MDA-MB-231, MCF-7) Agents.

2020 ◽  
Vol 20 ◽  
Author(s):  
Stefan Dimov ◽  
Anelia Ts. Mavrova ◽  
Denitsa Yancheva ◽  
Biliana Nikolova ◽  
Iana Tsoneva
Keyword(s):  
Breast Cancer ◽  
Cell Lines ◽  
Mechanism Of Action ◽  
Biologically Active ◽  
Breast Cancer Cell Lines ◽  
3T3 Cells ◽  
Fluorescence Study ◽  
Compound 21 ◽  
Mutational Activation ◽  
Mcf 7

Aims: The purpose was the synthesis of some new thienopyrimidines derivative of 1,3-disubstituted benzimidazoles and the evaluation of their cytotoxicity towards MDA-MB-231 and MCF-7 cell lines as well 3T3 cells. Background: An overexpression or mutational activation of TK receptors EGFR and HER2/neu are characteristic for tumors. It has been found that some thieno[2,3-d]pyrimidines exhibit better inhibitory activity against epidermal growth factor receptor (EGFR/ErbB-2) tyrosine kinase in comparison to aminoquinazolines. Breast cancer activity towards MDAMB-231 and MCF-7 cell lines by inhibiting EGFR was revealed by a novel 2-arylbenzimidazole. This motivated the synthesis of new thienopyrimidines possessing benzimidazole fragment in order to evaluate their cytotoxicity to the above mentioned cell lines. Objective: The objectives were the design and synthesis of a novel series thieno[2,3-d]pyrimidines bearing biologically active moieties as 1,3-disubstituted-benzimidazole heterocycle structurally similar to diaryl ureas in order to evaluate their cytotoxicity against MDA-MB-231, MCF-7 breast cancer cell lines. Methods: N,N-disubstituted benzimidazole-2-one carbonitriles were synthesized by Aza-Michael addition and used as precursors to generate some of the new thieno[2,3-d]pyrimidines in acidic medium. The interaction of chloroethyl-2- thienopyrimidines and 2-amino-benzimidazole resp. benzimidazol-2-one nitriles under solid-liquid transfer catalysis conditions lead to obtaining of new thienopyrimidines. MTT assay for cells survival was performed in order to establish the cytotoxicity of the tested compounds. Fluorescence study was used to elucidate some aspect of mechanism. Results: The effect of nine of the synthesized compounds was investigated towards MDA-MB-231 and MCF-7 cells as well as to 3T3 cells. Thieno[2,3-d]pyirimidine-4-one 16 (IC50 – 0.058 μM) and 21 (IC50 – 0.029 μM) possess high cytotoxicity against MDA-MB-231 cells after 24h. The most toxic against breast cancer MCF-7 cells was compounds 21 (IC50 – 0.074 μM), revealing lower cytotoxicity towards mouse fibroblast 3T3 cells with IC50 – 0.20 μM. SAR analisys was performed. Fluorescence study of the treatment of MDA-MB cells with compound 21 was carried out in order to clarify some aspects of mechanism of action. Conclusion: The relationship between cytotoxicity of compounds 14 and 20 against MCF-7 and 3T3 cells can suggest a similar mechanism of action. The antitumor potential of the tested compounds proves the necessity for further investigation to estimate the exact inhibition pathway in the cellular processes. The fluorescence study of the treatment of MDA-MB cells with compound 21 showed a rapid process of apoptosis.

scholarly journals Trace Amine-Associated Receptor 1 Trafficking to Cilia of Thyroid Epithelial Cells

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1518
Author(s):  
Maria Qatato ◽  
Vaishnavi Venugopalan ◽  
Alaa Al-Hashimi ◽  
Maren Rehders ◽  
Aaron D. Valentine ◽  
...  
Keyword(s):  
Cell Surface ◽  
Cell Lines ◽  
Human Thyroid ◽  
Apical Plasma Membrane ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Trace Amine ◽  
Rat Thyroid

Trace amine-associated receptor 1 (rodent Taar1/human TAAR1) is a G protein-coupled receptor that is mainly recognized for its functions in neuromodulation. Previous in vitro studies suggested that Taar1 may signal from intracellular compartments. However, we have shown Taar1 to localize apically and on ciliary extensions in rodent thyrocytes, suggesting that at least in the thyroid, Taar1 may signal from the cilia at the apical plasma membrane domain of thyrocytes in situ, where it is exposed to the content of the follicle lumen containing putative Taar1 ligands. This study was designed to explore mouse Taar1 (mTaar1) trafficking, heterologously expressed in human and rat thyroid cell lines in order to establish an in vitro system in which Taar1 signaling from the cell surface can be studied in future. The results showed that chimeric mTaar1-EGFP traffics to the apical cell surface and localizes particularly to spherical structures of polarized thyroid cells, procilia, and primary cilia upon serum-starvation. Moreover, mTaar1-EGFP appears to form high molecular mass forms, possibly homodimers and tetramers, in stably expressing human thyroid cell lines. However, only monomeric mTaar1-EGFP was cell surface biotinylated in polarized human thyrocytes. In polarized rat thyrocytes, mTaar1-EGFP is retained in the endoplasmic reticulum, while cilia were reached by mTaar1-EGFP transiently co-expressed in combination with an HA-tagged construct of the related mTaar5. We conclude that Taar1 trafficking to cilia depends on their integrity. The results further suggest that an in vitro cell model was established that recapitulates Taar1 trafficking in thyrocytes in situ, in principle, and will enable studying Taar1 signaling in future, thus extending our general understanding of its potential significance for thyroid autoregulation.

The effect of polysaccharide-based hydrogels on the response of antigen presenting cell lines to immunomodulators

2021 ◽  
Author(s):  
Jin Teng, Melody Chung ◽  
Chi Ming Laurence Lau ◽  
Ying Chau
Keyword(s):  
Immune Responses ◽  
Cell Lines ◽  
Foreign Material ◽  
Antigen Presenting Cell ◽  
Antigen Presenting

Hydrogel presents as foreign material to the host and participates in immune responses which would skew the biofunctions of immunologic loads (antigen and adjuvants) for in-situ DC priming. This study...

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