scholarly journals Replication Protein A Availability during DNA Replication Stress Is a Major Determinant of Cisplatin Resistance in Ovarian Cancer Cells

2018 ◽  
Vol 78 (19) ◽  
pp. 5561-5573 ◽  
Author(s):  
François Bélanger ◽  
Emile Fortier ◽  
Maxime Dubé ◽  
Jean-François Lemay ◽  
Rémi Buisson ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dna Replication ◽  
Cancer Cells ◽  
Cisplatin Resistance ◽  
Protein A ◽  
Replication Stress ◽  
Replication Protein A ◽  
Replication Protein ◽  
Ovarian Cancer Cells ◽  
Dna Replication Stress

scholarly journals Enhancer of mRNA Decapping protein 4 (EDC4) interacts with replication protein a (RPA) and contributes to Cisplatin resistance in cervical Cancer by alleviating DNA damage

Hereditas ◽  
2020 ◽  
Vol 157 (1) ◽  
Author(s):  
Xiaoling Wu ◽  
Youwen Zhong ◽  
Qing Chen ◽  
Xin Zhang ◽  
Hua Zhang
Keyword(s):  
Cervical Cancer ◽  
Dna Damage ◽  
Cell Growth ◽  
Cancer Cells ◽  
Cisplatin Resistance ◽  
Protein A ◽  
Replication Protein A ◽  
Replication Protein ◽  
Mrna Decapping ◽  
Cervical Cancer Cells

Abstract Background Cervical cancer (CC) is the third most common gynecological malignancy around the world. Cisplatin is an effective drug, but cisplatin resistance is a vital factor limiting the clinical usage of cisplatin. Enhancer of mRNA decapping protein 4 (EDC4) is a known regulator of mRNA decapping, which was related with genome stability and sensitivity of drugs. This research was to investigate the mechanism of EDC4 on cisplatin resistance in CC. Two human cervical cancer cell lines, HeLa and SiHa, were used to investigate the role of EDC4 on cisplatin resistance in vitro. The knockdown or overexpression of EDC4 or replication protein A (RPA) in HeLa or SiHa cells was performed by transfection. Cell viability was analyzed by MTT assay. The growth of cancer cells was evaluated by colony formation assay. DNA damage was measured by γH2AX (a sensitive DNA damage response marker) immunofluorescent staining. The binding of EDC4 and RPA was analyzed by immunoprecipitation. Results EDC4 knockdown in cervical cancer cells (HeLa and SiHa) enhanced cisplatin sensitivity and cisplatin induced cell growth inhibition and DNA damage. EDC4 overexpression reduced DNA damage caused by cisplatin and enhanced cell growth of cervical cancer cells. EDC4 could interact with RPA and promote RPA phosphorylation. RPA knockdown reversed the inhibitory effect of EDC4 on cisplatin-induced DNA damage. Conclusion The present results indicated that EDC4 is responsible for the cisplatin resistance partly through interacting with RPA in cervical cancer by alleviating DNA damage. This study indicated that EDC4 or RPA may be novel targets to combat chemotherapy resistance in cervical cancer. Graphical abstract

scholarly journals MTA2 sensitizes gastric cancer cells to PARP inhibition by induction of DNA replication stress

2021 ◽  
Vol 14 (10) ◽  
pp. 101167
Author(s):  
Jinwen Shi ◽  
Xiaofeng Zhang ◽  
Jin'e Li ◽  
Wenwen Huang ◽  
Yini Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Dna Replication ◽  
Cancer Cells ◽  
Replication Stress ◽  
Parp Inhibition ◽  
Gastric Cancer Cells ◽  
Dna Replication Stress

scholarly journals Stabilization of a G-Quadruplex from Unfolding by Replication Protein A Using Potassium and the Porphyrin TMPyP4

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Aishwarya Prakash ◽  
Fabien Kieken ◽  
Luis A. Marky ◽  
Gloria E. O. Borgstahl
Keyword(s):  
Dna Replication ◽  
Protein A ◽  
Thermal Stabilization ◽  
Replication Protein A ◽  
Replication Protein ◽  
Unique Problem ◽  
Ssdna Binding ◽  
Binding Domains ◽  
G Quadruplex ◽  
Stabilization Effect

Replication protein A (RPA) plays an essential role in DNA replication by binding and unfolding non-canonical single-stranded DNA (ssDNA) structures. Of the six RPA ssDNA binding domains (labeled A-F), RPA-CDE selectively binds a G-quadruplex forming sequence (5′-TAGGGGAAGGGTTGGAGTGGGTT-3′called Gq23). In K+, Gq23 forms a mixed parallel/antiparallel conformation, and in Na+Gq23 has a less stable (TMlowered by ∼20∘C), antiparallel conformation. Gq23 is intramolecular and 1D NMR confirms a stable G-quadruplex structure in K+. Full-length RPA and RPA-CDE-core can bind and unfold the Na+form of Gq23 very efficiently, but complete unfolding is not observed with the K+form. Studies with G-quadruplex ligands, indicate that TMPyP4 has a thermal stabilization effect on Gq23 in K+, and inhibits complete unfolding by RPA and RPA-CDE-core. Overall these data indicate that G-quadruplexes present a unique problem for RPA to unfold and ligands, such as TMPyP4, could possibly hinder DNA replication by blocking unfolding by RPA.

scholarly journals Formation of a Complex between Nucleolin and Replication Protein a after Cell Stress Prevents Initiation of DNA Replication

2000 ◽  
Vol 149 (4) ◽  
pp. 799-810 ◽  
Author(s):  
Yaron Daniely ◽  
James A. Borowiec
Keyword(s):  
Dna Replication ◽  
Ribosome Biogenesis ◽  
Protein A ◽  
Simian Virus 40 ◽  
Replication Protein A ◽  
Cell Stress ◽  
Replication Protein ◽  
Binding Studies

We used a biochemical screen to identify nucleolin, a key factor in ribosome biogenesis, as a high-affinity binding partner for the heterotrimeric human replication protein A (hRPA). Binding studies in vitro demonstrated that the two proteins physically interact, with nucleolin using an unusual contact with the small hRPA subunit. Nucleolin significantly inhibited both simian virus 40 (SV-40) origin unwinding and SV-40 DNA replication in vitro, likely by nucleolin preventing hRPA from productive interaction with the SV-40 initiation complex. In vivo, use of epifluorescence and confocal microscopy showed that heat shock caused a dramatic redistribution of nucleolin from the nucleolus to the nucleoplasm. Nucleolin relocalization was concomitant with a tenfold increase in nucleolin–hRPA complex formation. The relocalized nucleolin significantly overlapped with the position of hRPA, but only poorly with sites of ongoing DNA synthesis. We suggest that the induced nucleolin–hRPA interaction signifies a novel mechanism that represses chromosomal replication after cell stress.

scholarly journals HOTTIP-miR-205-ZEB2 Axis Confers Cisplatin Resistance to Ovarian Cancer Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Yu-Jie Dong ◽  
Wei Feng ◽  
Yan Li
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Cisplatin Resistance ◽  
Clinical Problem ◽  
Ovarian Cancer Cells ◽  
Stem Cell Markers ◽  
Gene Target ◽  
Gynecological Malignancy ◽  
Clonogenic Potential ◽  
Resistant Cells

Ovarian cancer is a deadly gynecological malignancy with resistance to cisplatin a major clinical problem. We evaluated a role of long non-coding (lnc) RNA HOTTIP (HOXA transcript at the distal tip) in the cisplatin resistance of ovarian cancer cells, using paired cisplatin sensitive and resistant A2780 cells along with the SK-OV-3 cells. HOTTIP was significantly elevated in cisplatin resistant cells and its silencing reversed the cisplatin resistance of resistant cells. HOTTIP was found to sponge miR-205 and therefore HOTTIP silenced cells had higher levels of miR-205. Downregulation of miR-205 could attenuate HOTTIP-silencing effects whereas miR-205 upregulation in resistant cells was found to re-sensitize cells to cisplatin. HOTTIP silencing also led to reduced NF-κB activation, clonogenic potential and the reduced expression of stem cell markers SOX2, OCT4, and NANOG, an effect that could be attenuated by miR-205. Finally, ZEB2 was identified as the gene target of miR-205, thus completing the elucidation of HOTTIP-miR-205-ZEB2 as the novel axis which is functionally involved in the determination of cisplatin resistance in ovarian cancer cells.

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