scholarly journals Molecular disruption of DNA polymerase β for platinum sensitisation and synthetic lethality in epithelial ovarian cancers

Oncogene ◽  
2021 ◽  
Author(s):  
Reem Ali ◽  
Adel Alblihy ◽  
Islam M. Miligy ◽  
Muslim L. Alabdullah ◽  
Mansour Alsaleem ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Dna Polymerase ◽  
Synthetic Lethality ◽  
Ovarian Cancer Cells ◽  
Dna Polymerase Β ◽  
Mesenchymal Transition ◽  
Platinum Sensitivity ◽  
Cycle Arrest ◽  
Ovarian Cancers

AbstractTargeting PARP1 [Poly(ADP-Ribose) Polymerase 1] for synthetic lethality is a new strategy for BRCA germ-line mutated or platinum sensitive ovarian cancers. However, not all patients respond due to intrinsic or acquired resistance to PARP1 inhibitor. Development of alternative synthetic lethality approaches is a high priority. DNA polymerase β (Polβ), a critical player in base excision repair (BER), interacts with PARP1 during DNA repair. Here we show that polβ deficiency is a predictor of platinum sensitivity in human ovarian tumours. Polβ depletion not only increased platinum sensitivity but also reduced invasion, migration and impaired EMT (epithelial to mesenchymal transition) of ovarian cancer cells. Polβ small molecular inhibitors (Pamoic acid and NSC666719) were selectively toxic to BRCA2 deficient cells and associated with double-strand breaks (DSB) accumulation, cell cycle arrest and increased apoptosis. Interestingly, PARG [Poly(ADP-Ribose) Glycohydrolase] inhibitor (PDD00017273) [but not PARP1 inhibitor (Olaparib)] was synthetically lethal in polβ deficient cells. Selective toxicity to PDD00017273 was associated with poly (ADP-ribose) accumulation, reduced nicotinamide adenine dinucleotide (NAD+) level, DSB accumulation, cell cycle arrest and increased apoptosis. In human tumours, polβ-PARG co-expression adversely impacted survival in patients. Our data provide evidence that polβ targeting is a novel strategy and warrants further pharmaceutical development in epithelial ovarian cancers.

scholarly journals Poly(ADP-ribose) Polymerase Activity Prevents Signaling Pathways for Cell Cycle Arrest after DNA Methylating Agent Exposure

2005 ◽  
Vol 280 (16) ◽  
pp. 15773-15785 ◽  
Author(s):  
Julie K. Horton ◽  
Donna F. Stefanick ◽  
Jana M. Naron ◽  
Padmini S. Kedar ◽  
Samuel H. Wilson
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Cell Cycle Arrest ◽  
Signaling Pathways ◽  
Dna Polymerase ◽  
S Phase ◽  
Dna Polymerase Β ◽  
Cycle Arrest ◽  
Parp Activity ◽  
Inhibition Of Dna Synthesis

Mouse fibroblasts, deficient in DNA polymerase β, are hypersensitive to monofunctional DNA methylating agents such as methyl methanesulfonate (MMS). Both wild-type and, in particular, repair-deficient DNA polymerase β null cells are highly sensitized to the cytotoxic effects of MMS by 4-amino-1,8-naphthalimide (4-AN), an inhibitor of poly(ADP-ribose) polymerase (PARP) activity. Experiments with synchronized cells suggest that exposure during S-phase of the cell cycle is required for the 4-AN effect. 4-AN elicits a similar extreme sensitization to the thymidine analog, 5-hydroxymethyl-2′-deoxyuridine, implicating the requirement for an intermediate of DNA repair. In PARP-1-expressing fibroblasts treated with a combination of MMS and 4-AN, a complete inhibition of DNA synthesis is apparent after 4 h, and by 24 h, all cells are arrested in S-phase of the cell cycle. Continuous incubation with 4-AN is required to maintain the cell cycle arrest. Caffeine, an inhibitor of the upstream checkpoint kinases ATM (ataxia telangiectasia-mutated) and ATR (ATM and Rad3-related), has no effect on the early inhibition of DNA synthesis, but cells are no longer able to maintain the block after 8 h. Instead, the addition of caffeine leads to arrest of cells in G2/M rather than S-phase after 24 h. Analysis of signaling pathways in cell extracts reveals an activation of Chk1 after treatment with MMS and 4-AN, which can be suppressed by caffeine. Our results suggest that inhibition of PARP activity results in sensitization to MMS through maintenance of an ATR and Chk1-dependent S-phase checkpoint.

scholarly journals Sulforaphane induces cell cycle arrest by protecting RB-E2F-1 complex in epithelial ovarian cancer cells

2010 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Christopher S Bryant ◽  
Sanjeev Kumar ◽  
Sreedhar Chamala ◽  
Jay Shah ◽  
Jagannath Pal ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Epithelial Ovarian Cancer ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Ovarian Cancer Cells ◽  
Cycle Arrest

Silencing of miR-1246 Induces Cell Cycle Arrest and Apoptosis in Cisplatin-Resistant Ovarian Cancer Cells by Promoting ZNF23 Transcription

2021 ◽  
pp. 1-13
Author(s):  
Lu Cai ◽  
Qian Zhang ◽  
Lili Du ◽  
Feiyun Zheng
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cell Cycle Progression ◽  
Luciferase Reporter ◽  
Cycle Phase ◽  
Ovarian Cancer Cells ◽  
Tunel Staining ◽  
Cycle Arrest

Ovarian cancer (OC) is the most frequent cause of death among patients with gynecologic malignancies. In recent years, the development of cisplatin (DDP) resistance has become an important reason for the poor prognosis of OC patients. Therefore, it is vital to explore the mechanism of DDP resistance in OC. In this study, microRNA-1246 (miR-1246) expression in OC and DDP-resistant OC cells was determined by RT-qPCR, and chemosensitivity to DDP was assessed by the CCK-8 assay. A dual-luciferase reporter assay was performed to confirm the interaction between miR-1246 and zinc finger 23 (<i>ZNF23</i>), while changes in <i>ZNF23</i> expression were monitored by RT-qPCR, immunofluorescence, and western blot assays. Moreover, cell proliferation, cycle phase, and apoptosis were determined by EdU staining, flow cytometry, TUNEL staining, and Hoechst staining. Our data showed that miR-1246 was highly expressed in DDP-resistant OVCAR-3 and TOV-112D cells. Functionally, overexpression of miR-1246 markedly enhanced DDP resistance and cell proliferation, and suppressed cell cycle arrest and apoptosis of OC cells. Inhibition of miR-1246 expression significantly attenuated DDP resistance and cell proliferation, and increased cell cycle arrest and apoptosis in DDP-resistant OC cells. Furthermore, <i>ZNF23</i> was identified as a target gene of miR-1246, and ZNF23 protein expression was notably downregulated in DDP-resistant OC cells. Moreover, overexpression of miR-1246 significantly downregulated the <i>ZNF23</i> levels in OVCAR-3 and TOV-112D cells, and inhibition of miR-1246 upregulated the <i>ZNF23</i> levels in the DDP-resistant OVCAR-3 and TOV-112D cells. In conclusion, miR-1246 might be a novel regulator of DDP-resistant OC that functions by regulating <i>ZNF23</i> expression in DDP-resistant cells, as well as cell proliferation, cell cycle progression, and apoptosis.

CA 125 Production and Release by Ovarian Cancer Cells In Vitro

1998 ◽  
Vol 13 (4) ◽  
pp. 200-206 ◽  
Author(s):  
E.P. Beck ◽  
A. Moldenhauer ◽  
E. Merkle ◽  
F. Kiesewetter ◽  
W. Jäger ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Human Tumor ◽  
Cellular Growth ◽  
Ca 125 ◽  
Ovarian Cancer Cells ◽  
Cell Cycle Distribution ◽  
Cycle Arrest

The antigenic determinant CA 125 is a high molecular weight glycoprotein which is elevated in more than 80% of patients with epithelial ovarian cancer. Despite its good performance as a human tumor marker, only little is known about its physiological function. According to recent publications, CA 125 production and release appear to be related to cellular growth. In order to investigate this putative relationship more closely, we analyzed the pattern of CA 125 production and release by ovarian cancer cells during exponential cell growth, during cell cycle arrest by colchicine and during inhibition of cellular protein synthesis by cycloheximide. The results were correlated with the cell cycle distribution. According to our results, the main determinant of CA 125 release into the culture supernatant is the total cell count. Although cell cycle arrest in the G2 + M phase by means of colchicine treatment resulted in the death of most cells, which was reflected by an increased release of CA 125, no differences in the intracellular production rate between colchicine treated and untreated cells were seen. In contrast, treatment of cells with cycloheximide not only resulted in decreasing cell numbers but also in a complete inhibition of CA 125 production by surviving cells.

scholarly journals The Role of Nitric Oxide in Cancer: Master Regulator or NOt?

2020 ◽  
Vol 21 (24) ◽  
pp. 9393
Author(s):  
Faizan H. Khan ◽  
Eoin Dervan ◽  
Dibyangana D. Bhattacharyya ◽  
Jake D. McAuliffe ◽  
Katrina M. Miranda ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Cell Cycle Progression ◽  
Epithelial To Mesenchymal Transition ◽  
Tumour Microenvironment ◽  
Master Regulator ◽  
Mesenchymal Transition ◽  
Cycle Arrest

Nitric oxide (NO) is a key player in both the development and suppression of tumourigenesis depending on the source and concentration of NO. In this review, we discuss the mechanisms by which NO induces DNA damage, influences the DNA damage repair response, and subsequently modulates cell cycle arrest. In some circumstances, NO induces cell cycle arrest and apoptosis protecting against tumourigenesis. NO in other scenarios can cause a delay in cell cycle progression, allowing for aberrant DNA repair that promotes the accumulation of mutations and tumour heterogeneity. Within the tumour microenvironment, low to moderate levels of NO derived from tumour and endothelial cells can activate angiogenesis and epithelial-to-mesenchymal transition, promoting an aggressive phenotype. In contrast, high levels of NO derived from inducible nitric oxide synthase (iNOS) expressing M1 and Th1 polarised macrophages and lymphocytes may exert an anti-tumour effect protecting against cancer. It is important to note that the existing evidence on immunomodulation is mainly based on murine iNOS studies which produce higher fluxes of NO than human iNOS. Finally, we discuss different strategies to target NO related pathways therapeutically. Collectively, we present a picture of NO as a master regulator of cancer development and progression.

scholarly journals α-Mangostin and Apigenin Induced Cell Cycle Arrest and Programmed Cell Death in SKOV-3 Ovarian Cancer Cells

2019 ◽  
Vol 35 (2) ◽  
pp. 167-179 ◽  
Author(s):  
Teeranai Ittiudomrak ◽  
Songchan Puthong ◽  
Sittiruk Roytrakul ◽  
Chanpen Chanchao
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Ovarian Cancer Cells ◽  
Cycle Arrest
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