Phosphorylation of histones in cells treated with hypertonic and acidic media.

Factors in the extracellular environment, specifically hypertonic or acidic growth media, are shown to alter the modification of histones in several cell lines. For histone 2A, changes in modification were visible in the mass pattern and were found to be primarily changes in phosphorylation. The increased modification of the core histones was quickly reversed when cells were returned to normal medium.

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Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166257 ◽

1996 ◽

Vol 54 ◽

pp. 758-759

Author(s):

D. W. Fairbain ◽

M.D. Standing ◽

K.L. O'Neill

Keyword(s):

Heat Shock ◽

Cell Lines ◽

Chromatin Condensation ◽

Membrane Integrity ◽

Resistant Cell ◽

Membrane Blebbing ◽

Late Loss ◽

Induced Apoptosis ◽

Dying Cells ◽

In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

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Identification and Characterization of the Genes Encoding the Core Histones and Histone Variants of Neurospora crassa

Genetics ◽

10.1093/genetics/160.3.961 ◽

2002 ◽

Vol 160 (3) ◽

pp. 961-973 ◽

Cited By ~ 1

Author(s):

Shan M Hays ◽

Johanna Swanson ◽

Eric U Selker

Keyword(s):

Neurospora Crassa ◽

Histone Variants ◽

Null Alleles ◽

Histone Genes ◽

Histone H4 ◽

Coding Regions ◽

The Core ◽

Genomic Arrangement ◽

Genes Encoding ◽

Core Histones

Abstract We have identified and characterized the complete complement of genes encoding the core histones of Neurospora crassa. In addition to the previously identified pair of genes that encode histones H3 and H4 (hH3 and hH4-1), we identified a second histone H4 gene (hH4-2), a divergently transcribed pair of genes that encode H2A and H2B (hH2A and hH2B), a homolog of the F/Z family of H2A variants (hH2Az), a homolog of the H3 variant CSE4 from Saccharomyces cerevisiae (hH3v), and a highly diverged H4 variant (hH4v) not described in other species. The hH4-1 and hH4-2 genes, which are 96% identical in their coding regions and encode identical proteins, were inactivated independently. Strains with inactivating mutations in either gene were phenotypically wild type, in terms of growth rates and fertility, but the double mutants were inviable. As expected, we were unable to isolate null alleles of hH2A, hH2B, or hH3. The genomic arrangement of the histone and histone variant genes was determined. hH2Az and the hH3-hH4-1 gene pair are on LG IIR, with hH2Az centromere-proximal to hH3-hH4-1 and hH3 centromere-proximal to hH4-1. hH3v and hH4-2 are on LG IIIR with hH3v centromere-proximal to hH4-2. hH4v is on LG IVR and the hH2A-hH2B pair is located immediately right of the LG VII centromere, with hH2A centromere-proximal to hH2B. Except for the centromere-distal gene in the pairs, all of the histone genes are transcribed toward the centromere. Phylogenetic analysis of the N. crassa histone genes places them in the Euascomycota lineage. In contrast to the general case in eukaryotes, histone genes in euascomycetes are few in number and contain introns. This may be a reflection of the evolution of the RIP (repeat-induced point mutation) and MIP (methylation induced premeiotically) processes that detect sizable duplications and silence associated genes.

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Gastrin regulates growth of human pancreatic cancer in a tonic and autocrine fashion

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1996.270.5.r1078 ◽

1996 ◽

Vol 270 (5) ◽

pp. R1078-R1084 ◽

Cited By ~ 12

Author(s):

J. P. Smith ◽

A. Shih ◽

Y. Wu ◽

P. J. McLaughlin ◽

I. S. Zagon

Keyword(s):

Gene Expression ◽

Pancreatic Cancer ◽

Cell Lines ◽

Cancer Cell ◽

Pancreatic Cancer Cell ◽

Cancer Cell Lines ◽

Human Pancreatic Cancer ◽

Growth Media ◽

Human Pancreatic Cancer Cell ◽

Cell Extracts

The gastrointestinal peptides gastrin and cholecystokinin (CCK) stimulate growth of human pancreatic cancer through a CCK-B/gastrin- like receptor. In the present study we evaluated whether growth of human pancreatic cancer is endogenously regulated by gastrin. Immunohistomical examination of BxPC-3 cells and tumor xenografts revealed specifc gastrin immunoreactivity. Gastrin was detected by radioimmunoassay in pancreatic cancer cell extracts and in pancreatic cancer cell extracts and in the growth media. With use of reverse-transcriptase polymerase chain reaction gastrin gene expression was detected in both cultured BxPC-3 cancer cells and transplanted tumors, as well as seven addition human pancreatic cancer cell lines. Growth of BxPC-3 human pancreatic cancer cell in serum-free medium was inhibited by the addition of the CCK-B/gastrin receptor antagonist L-365,260, and gastrin treatment reversed the inhibitory effect of the antagonist. A selective gastrin antibody (Ab repressed growth of BxPC-3 cells. Gastrin immunoreactivity was detected in fresh human pancreatic cancer specimens but not in normal human pancreatic tissue. These data provide the first evidence that growth of a human pancreatic cancer is tonically stimulated by the autocrine production of gastrin. Evidence for the ubiquity of this system was provided by the detection of gastrin gene expression in multiple human pancreatic cancer cell lines and detection of gastrin in cell lines and fresh pancreatic tumors.

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Cytotoxicity Study of Textile Fabrics Impregnated With CuO Nanoparticles in Mammalian Cells

International Journal of Toxicology ◽

10.1177/1091581817736712 ◽

2017 ◽

Vol 36 (6) ◽

pp. 478-484 ◽

Cited By ~ 9

Author(s):

Gagandeep Singh ◽

James Beddow ◽

Christopher Mee ◽

Lidia Maryniak ◽

Eadaoin M. Joyce ◽

...

Keyword(s):

Cell Lines ◽

Mammalian Cells ◽

Dermal Fibroblast ◽

Copper Oxide Nanoparticles ◽

Growth Media ◽

Indirect Contact ◽

Cuo Nps ◽

Mammalian Cell Lines ◽

Textile Fabrics ◽

Hdf Cells

Copper and copper compounds have multifunctional properties (antibacterial, antiviral, and antifungal) with promising applications. Copper in its nanoparticle (Cu NPs) forms has been widely used in various industrial and commercial applications. In the current research, the cytotoxic effects of textile fabrics impregnated with copper oxide nanoparticles (CuO NPs) were studied in mammalian cell lines. CuO NPs were impregnated onto textile substrates using 2 different techniques: the sonochemical generation and impregnation of NPs from metal complexes ( insitu) and a “throwing the stones” technology using commercially prepared CuO NPs. The cytotoxicity of these 2 textile fabric types was assayed on human dermal fibroblast (HDF) cells and human hepatocellular carcinoma cells (HepG2) and was evaluated by indirect contact using an MTT assay. The impregnated fabrics were not exposed to the cells, rather their leachates were used to test cytotoxicity. The fabrics were soaked into the growth media for up to 7 days, and the leachates from day 1 and day 7 were incubated with the cell lines for 24 hours prior to the testing. The discharge or leaching from antimicrobial nanomaterials into the surroundings and surface waters is posing a serious environmental threat, which needs to be addressed. Hence, with regard to product safety, it is a good approach to study the fabric leachates rather than the intact material. The results showed that CuO NPs are not toxic to HDF cells. However, cytotoxicity was seen in HepG2 cells with cell viability decreasing by 20% to 25% for all the fabrics after 24 hours.

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Thermodynamic Studies of the Core Histones: pH and Ionic Strength Effects on the Stability of the (H3−H4)/(H3−H4)2System†

Biochemistry ◽

10.1021/bi9518858 ◽

1996 ◽

Vol 35 (6) ◽

pp. 2037-2046 ◽

Cited By ~ 44

Author(s):

Vassiliki Karantza ◽

Ernesto Freire ◽

Evangelos N. Moudrianakis

Keyword(s):

Ionic Strength ◽

Thermodynamic Studies ◽

The Core ◽

Core Histones ◽

The Stability

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DNA tumor virus oncoproteins and retinoblastoma gene mutations share the ability to relieve the cell's requirement for cyclin D1 function in G1.

The Journal of Cell Biology ◽

10.1083/jcb.125.3.625 ◽

1994 ◽

Vol 125 (3) ◽

pp. 625-638 ◽

Cited By ~ 176

Author(s):

J Lukas ◽

H Müller ◽

J Bartkova ◽

D Spitkovsky ◽

A A Kjerulff ◽

...

Keyword(s):

Cell Cycle ◽

Complex Formation ◽

Cyclin D1 ◽

Cell Lines ◽

T Antigen ◽

Regulatory Function ◽

Retinoblastoma Gene ◽

Checkpoint Control ◽

Wild Type ◽

In Cells

The retinoblastoma gene product (pRB) participates in the regulation of the cell division cycle through complex formation with numerous cellular regulatory proteins including the potentially oncogenic cyclin D1. Extending the current view of the emerging functional interplay between pRB and D-type cyclins, we now report that cyclin D1 expression is positively regulated by pRB. Cyclin D1 mRNA and protein is specifically downregulated in cells expressing SV40 large T antigen, adenovirus E1A, and papillomavirus E7/E6 oncogene products and this effect requires intact RB-binding, CR2 domain of E1A. Exceptionally low expression of cyclin D1 is also seen in genetically RB-deficient cell lines, in which ectopically expressed wild-type pRB results in specific induction of this G1 cyclin. At the functional level, antibody-mediated cyclin D1 knockout experiments demonstrate that the cyclin D1 protein, normally required for G1 progression, is dispensable for passage through the cell cycle in cell lines whose pRB is inactivated through complex formation with T antigen, E1A, or E7 oncoproteins as well as in cells which have suffered loss-of-function mutations of the RB gene. The requirement for cyclin D1 function is not regained upon experimental elevation of cyclin D1 expression in cells with mutant RB, while reintroduction of wild-type RB into RB-deficient cells leads to restoration of the cyclin D1 checkpoint. These results strongly suggest that pRB serves as a major target of cyclin D1 whose cell cycle regulatory function becomes dispensable in cells lacking functional RB. Based on available data including this study, we propose a model for an autoregulatory feedback loop mechanism that regulates both the expression of the cyclin D1 gene and the activity of pRB, thereby contributing to a G1 phase checkpoint control in cycling mammalian cells.

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EB1 and EB3 regulate microtubule minus end organization and Golgi morphology

The Journal of Cell Biology ◽

10.1083/jcb.201701024 ◽

2017 ◽

Vol 216 (10) ◽

pp. 3179-3198 ◽

Cited By ~ 35

Author(s):

Chao Yang ◽

Jingchao Wu ◽

Cecilia de Heus ◽

Ilya Grigoriev ◽

Nalan Liv ◽

...

Keyword(s):

Cell Division ◽

Cell Lines ◽

Protein Complexes ◽

Focal Adhesions ◽

Microtubule Organization ◽

The Core ◽

Microtubule Polymerization ◽

Golgi Membranes ◽

Core Components ◽

Knockout Technology

End-binding proteins (EBs) are the core components of microtubule plus end tracking protein complexes, but it is currently unknown whether they are essential for mammalian microtubule organization. Here, by using CRISPR/Cas9-mediated knockout technology, we generated stable cell lines lacking EB2 and EB3 and the C-terminal partner-binding half of EB1. These cell lines show only mild defects in cell division and microtubule polymerization. However, the length of CAMSAP2-decorated stretches at noncentrosomal microtubule minus ends in these cells is reduced, microtubules are detached from Golgi membranes, and the Golgi complex is more compact. Coorganization of microtubules and Golgi membranes depends on the EB1/EB3–myomegalin complex, which acts as membrane–microtubule tether and counteracts tight clustering of individual Golgi stacks. Disruption of EB1 and EB3 also perturbs cell migration, polarity, and the distribution of focal adhesions. EB1 and EB3 thus affect multiple interphase processes and have a major impact on microtubule minus end organization.

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Nuclear RanGAP Is Required for the Heterochromatin Assembly and Is Reciprocally Regulated by Histone H3 and Clr4 Histone Methyltransferase in Schizosaccharomyces pombe

Molecular Biology of the Cell ◽

10.1091/mbc.e05-09-0893 ◽

2006 ◽

Vol 17 (6) ◽

pp. 2524-2536 ◽

Cited By ~ 15

Author(s):

Hitoshi Nishijima ◽

Jun-ichi Nakayama ◽

Tomoko Yoshioka ◽

Ayumi Kusano ◽

Hideo Nishitani ◽

...

Keyword(s):

Schizosaccharomyces Pombe ◽

Histone H3 ◽

Inhibitory Effect ◽

Stable Complex ◽

Gtpase Activating Protein ◽

Ran Gtpase ◽

The Core ◽

Trimeric Complex ◽

Core Histones ◽

Heterochromatin Assembly

Although the Ran GTPase-activating protein RanGAP mainly functions in the cytoplasm, several lines of evidence indicate a nuclear function of RanGAP. We found that Schizosaccharomyces pombe RanGAP, SpRna1, bound the core of histone H3 (H3) and enhanced Clr4-mediated H3-lysine 9 (K9) methylation. This enhancement was not observed for methylation of the H3-tail containing K9 and was independent of SpRna1–RanGAP activity, suggesting that SpRna1 itself enhances Clr4-mediated H3-K9 methylation via H3. Although most SpRna1 is in the cytoplasm, some cofractionated with H3. Sprna1ts mutations caused decreases in Swi6 localization and H3-K9 methylation at all three heterochromatic regions of S. pombe. Thus, nuclear SpRna1 seems to be involved in heterochromatin assembly. All core histones bound SpRna1 and inhibited SpRna1–RanGAP activity. In contrast, Clr4 abolished the inhibitory effect of H3 on the RanGAP activity of SpRna1 but partially affected the other histones. SpRna1 formed a trimeric complex with H3 and Clr4, suggesting that nuclear SpRna1 is reciprocally regulated by histones, especially H3, and Clr4 on the chromatin to function for higher order chromatin assembly. We also found that SpRna1 formed a stable complex with Xpo1/Crm1 plus Ran-GTP, in the presence of H3.

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