scholarly journals Specific G1-S phase cell cycle block by beryllium as demonstrated by cytofluorometric analysis

1983 ◽  
Vol 216 (3) ◽  
pp. 773-776 ◽  
Author(s):  
D N Skilleter ◽  
R J Price ◽  
R F Legg
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cell Line ◽  
S Phase ◽  
Cell Cycle Analysis ◽  
Phase Cell ◽  
Cell Cycle Block ◽  
Synchronized Cultures

Inhibition of cell division by beryllium (Be2+) has been examined in synchronized cultures of a liver-derived cell line (BL9L cells) using cytofluorometric cell cycle analysis. Results show that a selective dose-related block of the G1-pre-S transition is produced, with other periods of the cell cycle appearing relatively insensitive.

Cell cycle arrest caused by CLN gene deficiency in Saccharomyces cerevisiae resembles START-I arrest and is independent of the mating-pheromone signalling pathway

1990 ◽  
Vol 10 (12) ◽  
pp. 6482-6490
Author(s):  
F R Cross
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Cell Cycle Arrest ◽  
S Phase ◽  
Signalling Pathway ◽  
Phase Cell ◽  
Glucose Medium ◽  
Coding Sequence ◽  
Cycle Arrest

Null mutations in three genes encoding cyclin-like proteins (CLN1, CLN2, and CLN3) in Saccharomyces cerevisiae cause cell cycle arrest in G1 (cln arrest). In cln1 cln2 cln3 strains bearing plasmids containing the CLN3 (also called WHI1 or DAF1) coding sequence under the transcriptional control of a galactose-regulated promoter, shift from galactose to glucose medium (shutting off synthesis of CLN3 mRNA) allowed completion of cell cycles in progress but caused arrest in the ensuing unbudded G1 phase. Cell growth was not inhibited in arrested cells. Cell division occurred in glucose medium even if cells were arrested in S phase during the initial 2 h of glucose treatment, suggesting that CLN function may not be required in the cell cycle after S phase. However, when the coding sequence of the hyperactive C-terminal truncation allele CLN3-2 (formerly DAF1-1) was placed under GAL control, cells went through multiple cycles before arresting after a shift from galactose to glucose. These results suggest that the C terminus of the wild-type protein confers functional instability. cln-arrested cells are mating competent. However, cln arrest is distinct from constitutive activation of the mating-factor signalling pathway because cln-arrested cells were dependent on the addition of pheromone both for mating and for induction of an alpha-factor-induced transcript, FUS1, and because MATa/MAT alpha (pheromone-nonresponsive) strains were capable of cln arrest in G1 (although a residual capacity for cell division before arrest was observed in MATa/MAT alpha strains). These results are consistent with a specific CLN requirement for START transit.

scholarly journals HPO iron chelator, CP655, causes the G1/S phase cell cycle block via p21 upregulation

2020 ◽  
Vol 8 (4) ◽  
pp. 568-583
Author(s):  
Damini Tewari ◽  
Katie Lloyd‐Jones ◽  
Robert C. Hider ◽  
Helen Collins
Keyword(s):  
Cell Cycle ◽  
Iron Chelator ◽  
S Phase ◽  
Phase Cell ◽  
Cell Cycle Block

scholarly journals Cell cycle arrest caused by CLN gene deficiency in Saccharomyces cerevisiae resembles START-I arrest and is independent of the mating-pheromone signalling pathway.

1990 ◽  
Vol 10 (12) ◽  
pp. 6482-6490 ◽  
Author(s):  
F R Cross
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Cell Cycle Arrest ◽  
S Phase ◽  
Signalling Pathway ◽  
Phase Cell ◽  
Glucose Medium ◽  
Coding Sequence ◽  
Cycle Arrest

Null mutations in three genes encoding cyclin-like proteins (CLN1, CLN2, and CLN3) in Saccharomyces cerevisiae cause cell cycle arrest in G1 (cln arrest). In cln1 cln2 cln3 strains bearing plasmids containing the CLN3 (also called WHI1 or DAF1) coding sequence under the transcriptional control of a galactose-regulated promoter, shift from galactose to glucose medium (shutting off synthesis of CLN3 mRNA) allowed completion of cell cycles in progress but caused arrest in the ensuing unbudded G1 phase. Cell growth was not inhibited in arrested cells. Cell division occurred in glucose medium even if cells were arrested in S phase during the initial 2 h of glucose treatment, suggesting that CLN function may not be required in the cell cycle after S phase. However, when the coding sequence of the hyperactive C-terminal truncation allele CLN3-2 (formerly DAF1-1) was placed under GAL control, cells went through multiple cycles before arresting after a shift from galactose to glucose. These results suggest that the C terminus of the wild-type protein confers functional instability. cln-arrested cells are mating competent. However, cln arrest is distinct from constitutive activation of the mating-factor signalling pathway because cln-arrested cells were dependent on the addition of pheromone both for mating and for induction of an alpha-factor-induced transcript, FUS1, and because MATa/MAT alpha (pheromone-nonresponsive) strains were capable of cln arrest in G1 (although a residual capacity for cell division before arrest was observed in MATa/MAT alpha strains). These results are consistent with a specific CLN requirement for START transit.

scholarly journals Caspase-2 regulates S-phase cell cycle events to protect from DNA damage accumulation independent of apoptosis

2021 ◽  
Author(s):  
Ashley Boice ◽  
Raj Kumari Pandita ◽  
Karla Lopez ◽  
Melissa J Pourpak ◽  
Chloe I Charendoff ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
S Phase ◽  
Phase Cell ◽  
Replication Forks ◽  
Cycle Arrest ◽  
Dividing Cells ◽  
Caspase 2 ◽  
Stalled Replication Forks

In addition to its classical role in apoptosis, accumulating evidence suggests that caspase-2 has non-apoptotic functions, including regulation of cell division. Loss of caspase-2 is known to increase proliferation rates but how caspase-2 is regulating this process is currently unclear. We show that caspase-2 is activated in dividing cells in G1- and early S-phase. In the absence of caspase-2, cells exhibit numerous S-phase defects including delayed exit from S-phase, S-phase-associated chromosomal aberrations, and increased DNA damage following S-phase arrest. In addition, caspase-2-deficient cells have a higher frequency of stalled replication forks, decreased DNA fiber length, and impeded progression of DNA replication tracts. This indicates that caspase-2 reduces replication stress and promotes replication fork protection to maintain genomic stability. These functions are independent of the pro-apoptotic function of caspase-2 because blocking caspase-2-induced cell death had no effect on cell division or DNA damage-induced cell cycle arrest. Thus, our data supports a model where caspase-2 regulates cell cycle events to protect from the accumulation of DNA damage independently of its pro-apoptotic function.

5-Nitro-Thiophene-Thiosemicarbazone Derivatives Present Antitumor Activity Mediated by Apoptosis and DNA Intercalation

2019 ◽  
Vol 19 (13) ◽  
pp. 1075-1091 ◽  
Author(s):  
Karla Mirella Roque Marques ◽  
Maria Rodrigues do Desterro ◽  
Sandrine Maria de Arruda ◽  
Luiz Nascimento de Araújo Neto ◽  
Maria do Carmo Alves de Lima ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Antitumor Activity ◽  
Cell Line ◽  
Mitochondrial Membrane ◽  
In Vitro Cytotoxicity ◽  
Dna Intercalation ◽  
Phase Cell ◽  
Fluorescence Studies ◽  
In Silico Studies

Background: Considering the need for the development of new antitumor drugs, associated with the great antitumor potential of thiophene and thiosemicarbazonic derivatives, in this work we promote molecular hybridization approach to synthesize new compounds with increased anticancer activity. Objective: Investigate the antitumor activity and their likely mechanisms of action of a series of N-substituted 2-(5-nitro-thiophene)-thiosemicarbazone derivatives. Methods: Methods were performed in vitro (cytotoxicity, cell cycle progression, morphological analysis, mitochondrial membrane potential evaluation and topoisomerase assay), spectroscopic (DNA interaction studies), and in silico studies (docking and molecular modelling). Results: Most of the compounds presented significant inhibitory activity; the NCIH-292 cell line was the most resistant, and the HL-60 cell line was the most sensitive. The most promising compound was LNN-05 with IC50 values ranging from 0.5 to 1.9 µg.mL-1. The in vitro studies revealed that LNN-05 was able to depolarize (dose-dependently) the mitochondrial membrane, induceG1 phase cell cycle arrest noticeably, promote morphological cell changes associated with apoptosis in chronic human myelocytic leukaemia (K-562) cells, and presented no topoisomerase II inhibition. Spectroscopic UV-vis and molecular fluorescence studies showed that LNN compounds interact with ctDNA forming supramolecular complexes. Intercalation between nitrogenous bases was revealed through KI quenching and competitive ethidium bromide assays. Docking and Molecular Dynamics suggested that 5-nitro-thiophene-thiosemicarbazone compounds interact against the larger DNA groove, and corroborating the spectroscopic results, may assume an intercalating interaction mode. Conclusion: Our findings highlight 5-nitro-thiophene-thiosemicarbazone derivatives, especially LNN-05, as a promising new class of compounds for further studies to provide new anticancer therapies.

Identification and Expression Analysis of CD73 Inhibitors in Cervical Cancer

2020 ◽  
Vol 16 ◽  
Author(s):  
Jamshed Iqbal ◽  
Ayesha Basharat ◽  
Sehrish Bano ◽  
Syed Mobasher Ali Abid ◽  
Julie Pelletier ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Western Blot ◽  
Hela Cell ◽  
Cell Line ◽  
Cell Apoptosis ◽  
Immunofluorescence Staining ◽  
Cell Cycle Analysis ◽  
Hela Cell Line ◽  
Cell Line Hela

Aims: The present study was conducted to examine the inhibitory effects of synthesized sulfonylhydrazones on the expression of CD73 (ecto-5′-NT). Background: CD73 (ecto-5′-NT) represents the most significant class of ecto-nucleotidases which are mainly responsible for dephosphorylation of adenosine monophosphate to adenosine. Inhibition of CD73 played an important role in the treatment of cancer, autoimmune disorders, precancerous syndromes, and some other diseases associated with CD73 activity. Objective: Keeping in view the significance of CD73 inhibitor in the treatment of cervical cancer, a series of sulfonylhydrazones (3a-3i) derivatives synthesized from 3-formylchromones were evaluated. Methods: All sulfonylhydrazones (3a-3i) were evaluated for their inhibitory activity towards CD73 (ecto-5′-NT) by the malachite green assay and their cytotoxic effect was investigated on HeLa cell line using MTT assay. Secondly, most potent compound was selected for cell apoptosis, immunofluorescence staining and cell cycle analysis. After that, CD73 mRNA and protein expression were analyzed by real-time PCR and Western blot. Results: Among all compounds, 3h, 3e, 3b, and 3c were found the most active against rat-ecto-5′-NT (CD73) enzyme with IC50 (µM) values of 0.70 ± 0.06 µM, 0.87 ± 0.05 µM, 0.39 ± 0.02 µM and 0.33 ± 0.03 µM, respectively. These derivatives were further evaluated for their cytotoxic potential against cancer cell line (HeLa). Compound 3h and 3c showed the cytotoxicity at IC50 value of 30.20 ± 3.11 µM and 86.02 ± 7.11 µM, respectively. Furthermore, compound 3h was selected for cell apoptosis, immunofluorescence staining and cell cycle analysis which showed promising apoptotic effect in HeLa cells. Additionally, compound 3h was further investigated for its effect on expression of CD73 using qRT-PCR and western blot. Conclusion: Among all synthesized compounds (3a-3i), Compound 3h (E)-N'-((6-ethyl-4-oxo-4H-chromen-3-yl) methylene)-4-methylbenzenesulfonohydrazide was identified as most potent compound. Additional expression studies conducted on HeLa cell line proved that this compound successfully decreased the expression level of CD73 and thus inhibiting the growth and proliferation of cancer cells.

Novel Anthraquinone Derivatives as Dual Inhibitors of Topoisomerase 2 and Casein Kinase 2: In Silico Studies, Synthesis and Biological Evaluation on Leukemic Cell Lines

2019 ◽  
Vol 18 (11) ◽  
pp. 1551-1562 ◽  
Author(s):  
Abbas Kabir ◽  
Kalpana Tilekar ◽  
Neha Upadhyay ◽  
C.S. Ramaa
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Cell Lines ◽  
Biological Evaluation ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Cell Cycle Analysis ◽  
Protein Targets ◽  
Topoisomerase 2 ◽  
Dual Inhibitors

Background: Cancer being a complex disease, single targeting agents remain unsuccessful. This calls for “multiple targeting”, wherein a single drug is so designed that it will modulate the activity of multiple protein targets. Topoisomerase 2 (Top2) helps in removing DNA tangles and super-coiling during cellular replication, Casein Kinase 2 (CK2) is involved in the phosphorylation of a multitude of protein targets. Thus, in the present work, we have tried to develop dual inhibitors of Top2 and CK2. Objective: With this view, in the present work, 2 human proteins, Top2 and CK2 have been targeted to achieve the anti-proliferative effects. Methods: Novel 1-acetylamidoanthraquinone (3a-3y) derivatives were designed, synthesized and their structures were elucidated by analytical and spectral characterization techniques (FTIR, 1H NMR, 13C NMR and Mass Spectroscopy). The synthesized compounds were then subjected to evaluation of cytotoxic potential by the Sulforhodamine B (SRB) protein assay, using HL60 and K562 cell lines. Ten compounds were analyzed for Top2, CK2 enzyme inhibitory potential. Further, top three compounds were subjected to cell cycle analysis. Results: The compounds 3a to 3c, 3e, 3f, 3i to 3p, 3t and 3x showed excellent cytotoxic activity to HL-60 cell line indicating their high anti-proliferative potential in AML. The compounds 3a to 3c, 3e, 3f, 3i to 3p and 3y have shown good to moderate activity on K-562 cell line. Compounds 3e, 3f, 3i, 3x and 3y were found more cytotoxic than standard doxorubicin. In cell cycle analysis, the cells (79-85%) were found to arrest in the G0/G1 phase. Conclusion: We have successfully designed, synthesized, purified and structurally characterized 1- acetylamidoanthraquinone derivatives. Even though our compounds need design optimization to further increase enzyme inhibition, their overall anti-proliferative effects were found to be encouraging.

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