Late Mitosis/Early G 1 Phase and Mid-G 1 Phase Are Not Hypersensitive Cell Cycle Phases for Neoplastic Transformation of HeLa X Skin Fibroblast Human Hybrid Cells Induced by Fission-Spectrum Neutrons

Background: Different cellular responses influence the progress of cancer. In this study, we have investigated the effect of hydrogen peroxide and quercetin induced changes on cell viability, apoptosis and oxidative stress in human hepatocellular carcinoma (HepG2) cells. Methods: The effects of hydrogen peroxide and quercetin on cell viability, cell cycle phases and oxidative stress related cellular changes were investigated. Cell viability was assessed by WST-1 assay. Apoptosis rate, cell cycle phase changes and oxidative stress were measured by flow cytometry. Protein expressions of p21, p27, p53, NF-Kβ-p50 and proteasome activity were determined by Western blot and fluorometry, respectively. Results: Hydrogen peroxide and quercetin treatment resulted in decreased cell viability and increased apoptosis in HepG2 cells. Proteasome activity was increased by hydrogen peroxide but decreased by quercetin treatment. Conclusion: Both agents resulted in decreased p53 protein expression and increased cell death by different mechanisms regarding proteostasis and cell cycle phases.

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miRNA-mediated Drug Repurposing Unveiled Potential Candidate Drugs for Prolactinoma Treatment

Neuroendocrinology ◽

10.1159/000515801 ◽

2021 ◽

Author(s):

Büşra Aydin ◽

Sema Arslan ◽

Fatih Bayraklı ◽

Betül Karademir ◽

Kazim Yalcin Arga

Keyword(s):

Cell Cycle ◽

Data Integration ◽

Cell Viability ◽

Drug Repurposing ◽

Serum Prolactin ◽

Drug Candidates ◽

Mirna Level ◽

Level Data ◽

Cell Cycle Phases

Introduction: Prolactinomas, also called lactotroph adenomas, are the most encountered type of hormone-secreting pituitary neuroendocrine tumors (PitNET) in the clinic. The preferred first-line therapy is a medical treatment with dopamine agonists (DA), mainly cabergoline, to reduce serum prolactin levels, tumor volume, and mass effect. However, in some cases, patients have displayed DA-resistance with aggressive tumor behavior or are faced with recurrence after drug withdrawal. Also, currently used therapeutics have notorious side effects and impair the life quality of the patients. Methods: Since the amalgamation of clinical and laboratory data besides tumor histopathogenesis and transcriptional regulatory features of the tumor emerge to exhibit essential roles in the behavior and progression of prolactinomas, in this work, we integrated mRNA and microRNA (miRNA) level transcriptome data that exploit disease-specific signatures in addition to biological and pharmacological data to elucidate a rational prioritization of pathways and drugs in prolactinoma. Results: We identified eight drug candidates through drug repurposing based on mRNA-miRNA level data integration and evaluated their potential through in vitro assays in the MMQ cell line. Seven re-purposed drugs including 5-flourocytosine, nortriptyline, neratinib, puromycin, taxifolin, vorinostat, and zileuton were proposed as potential drug candidates for the treatment of prolactinoma. We further hypothesized possible mechanisms of drug action on MMQ cell viability through analyzing PI3K/Akt signaling pathway and cell cycle arrest via flow cytometry and western blotting. Discussion: We presented the transcriptomic landscape of prolactinoma through miRNA and mRNA level data integration and proposed repurposed drug candidates based on this integration. We validated our findings through testing cell viability, cell cycle phases, and PI3K/Akt protein expressions. Effects of the drugs on cell cycle phases and inhibition of PI3K/Akt pathway by all drugs gave us promising output for further studies using these drugs in the treatment of prolactinoma. This is the first study that reports miRNA-mediated repurposed drugs for prolactinoma treatment via in vitro experiments.

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Q-FIHC: Quantification of fluorescence immunohistochemistry to analysep63 isoforms and cell cycle phases in human limbal stem cells

Microscopy Research and Technique ◽

10.1002/jemt.20375 ◽

2006 ◽

Vol 69 (12) ◽

pp. 983-991 ◽

Cited By ~ 42

Author(s):

Enzo Di Iorio ◽

Vanessa Barbaro ◽

Stefano Ferrari ◽

Claudio Ortolani ◽

Michele De Luca ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Limbal Stem Cells ◽

Cell Cycle Phases ◽

Fluorescence Immunohistochemistry

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Genetic and Biochemical Evaluation of the Importance of Cdc6 in Regulating Mitotic Exit

Molecular Biology of the Cell ◽

10.1091/mbc.e03-06-0384 ◽

2003 ◽

Vol 14 (11) ◽

pp. 4592-4604 ◽

Cited By ~ 35

Author(s):

Vincent Archambault ◽

Caihong X. Li ◽

Alan J. Tackett ◽

Ralph Wäsch ◽

Brian T. Chait ◽

...

Keyword(s):

Cell Cycle ◽

Mitotic Exit ◽

Terminal Region ◽

Cyclin Dependent Kinase ◽

Replication Control ◽

Mitotic Cyclin ◽

Biochemical Evaluation ◽

Inhibitory Domain ◽

Late Mitosis ◽

Control Protein

We evaluated the hypothesis that the N-terminal region of the replication control protein Cdc6 acts as an inhibitor of cyclin-dependent kinase (Cdk) activity, promoting mitotic exit. Cdc6 accumulation is restricted to the period from mid-cell cycle until the succeeding G1, due to proteolytic control that requires the Cdc6 N-terminal region. During late mitosis, Cdc6 is present at levels comparable with Sic1 and binds specifically to the mitotic cyclin Clb2. Moderate overexpression of Cdc6 promotes viability of CLB2Δdb strains, which otherwise arrest at mitotic exit, and rescue is dependent on the N-terminal putative Cdk-inhibitory domain. These observations support the potential for Cdc6 to inhibit Clb2-Cdk, thus promoting mitotic exit. Consistent with this idea, we observed a cytokinesis defect in cdh1Δ sic1Δ cdc6Δ2–49 triple mutants. However, we were able to construct viable strains, in three different backgrounds, containing neither SIC1 nor the Cdc6 Cdk-inhibitory domain, in contradiction to previous work. We conclude, therefore, that although both Cdc6 and Sic1 have the potential to facilitate mitotic exit by inhibiting Clb2-Cdk, mitotic exit nevertheless does not require any identified stoichiometric inhibitor of Cdk activity.

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Continued initiation of DNA synthesis in arginine-deprived Chinese hamster ovary cells.

The Journal of Cell Biology ◽

10.1083/jcb.73.1.200 ◽

1977 ◽

Vol 73 (1) ◽

pp. 200-205 ◽

Cited By ~ 3

Author(s):

A S Weissfeld ◽

H Rouse

Keyword(s):

Cell Cycle ◽

Dna Synthesis ◽

Chinese Hamster Ovary ◽

Cho Cells ◽

Chinese Hamster Ovary Cells ◽

Chinese Hamster ◽

Cell Multiplication ◽

Ovary Cells ◽

Cell Cycle Phases

When exponentially growing CHO cells were deprived of arginine (Arg), cell multiplication ceased after 12 h, but initiation of DNA synthesis continued: after 48 h of starvation with continuous [3H]thymidine exposure, 85% of the population had incorporated label, as detected autoradiographically. Consideration of the distribution of exponential cells in the various cell cycle phases leads to a calculation that most cells in G1 at the time that Arg was removed, as well as those in S, engaged in some DNA synthesis during starvation. In contrast, isoleucine (Ile)-starved cells did not initiate DNA synthesis, as has been reported by others. Experiments with cells synchronized by mitotic selection confirmed this difference in Arg- and Ile- deprived behavior, but also showed that cells which underwent the mitosis leads to G1 transition during Arg starvation remained arrested in G1 (G0?). The results suggest that Arg-deprived cells continue to maintain some proliferative function(s) while Ile-deprived cells do not.

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