scholarly journals Downregulation of RIF1 Enhances Sensitivity to Platinum-Based Chemotherapy in Epithelial Ovarian Cancer (EOC) by Regulating Nucleotide Excision Repair (NER) Pathway

2018 ◽  
Vol 46 (5) ◽  
pp. 1971-1984 ◽  
Author(s):  
Yong-Bin Liu ◽  
Ying Mei ◽  
Zheng-Wen Tian ◽  
Jing Long ◽  
Chen-Hui Luo ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Epithelial Ovarian Cancer ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Online Databases ◽  
Platinum Based Chemotherapy ◽  
Nucleotide Excision ◽  
Induced Apoptosis ◽  
Platinum Chemotherapy

Background/Aims: Rap1 interacting factor 1 (RIF1) was deemed to be involved in replication timing regulation and DNA damage response. However, little is known about the role of RIF1 in malignancies. Thus, this study aimed to investigate whether the expression of RIF1 is relevant to the response of epithelial ovarian cancer (EOC) patients to cisplatin chemotherapy and its underlying mechanism. Methods: Immunohistochemistry was used for detecting the expression of RIF1 in 72 human ovarian cancer tissues followed by association analysis of RIF1 expression with patients’ responses to platinum-based chemotherapy. The survival analysis of ovarian patients based on platinum chemotherapy was analyzed using online databases. RNA interference of RIF1 was carried out in OVCAR3 and A2780 cell lines, to determine the effect of lacking RIF1 expression on cellular responses to cisplatin by using MTS assay. The nucleotide excision repair (NER) capacity of these cells was assessed by using host-cell reactivation and UV sensitivity assay. Western Blot analysis was carried out to determine the effect of RIF1 on the proteins of NER and apoptosis signaling pathway by using RIF1 knockdown cells. BALB/c nude mice model was used for detection of response to cisplatin in vivo. Results: RIF1 expression was significantly associated with the response of ovarian patients to platinum-based chemotherapy (P< 0.01). In cohorts from online databases, high expression of RIF1 was associated with higher mortality of EOC patients based on platinum chemotherapy (P < 0.01). RIF1 knockdown increased sensitivity to cisplatin in EOC in vitro and in vivo. Deletion of RIF1 impaired the NER activity by inhibiting the NER proteins in ovarian cancer cells. Besides, knockdown of RIF1 enhanced cisplatin-induced apoptosis. Conclusions: RIF1 plays an important role in regulating the expression of NER proteins, which in turn contributes to cellular response to cisplatin and EOC patients’ response to platinum-based chemotherapy. RIF1 knockdown also promotes cisplatin-induced apoptosis. RIF1 may serve as a novel biomarker for predicting platinum-based chemosensitivity and the prognosis of EOC patients.

scholarly journals Nucleotide Excision Repair in Human Cells

2013 ◽  
Vol 288 (29) ◽  
pp. 20918-20926 ◽  
Author(s):  
Jinchuan Hu ◽  
Jun-Hyuk Choi ◽  
Shobhan Gaddameedhi ◽  
Michael G. Kemp ◽  
Joyce T. Reardon ◽  
...  
Keyword(s):  
Nucleotide Excision Repair ◽  
Genomic Dna ◽  
Excision Repair ◽  
Human Cells ◽  
Naked Dna ◽  
Nucleotide Excision ◽  
Uv Photoproducts ◽  
Mutant Cells

Nucleotide excision repair is the sole mechanism for removing the major UV photoproducts from genomic DNA in human cells. In vitro with human cell-free extract or purified excision repair factors, the damage is removed from naked DNA or nucleosomes in the form of 24- to 32-nucleotide-long oligomers (nominal 30-mer) by dual incisions. Whether the DNA damage is removed from chromatin in vivo in a similar manner and what the fate of the excised oligomer was has not been known previously. Here, we demonstrate that dual incisions occur in vivo identical to the in vitro reaction. Further, we show that transcription-coupled repair, which operates in the absence of the XPC protein, also generates the nominal 30-mer in UV-irradiated XP-C mutant cells. Finally, we report that the excised 30-mer is released from the chromatin in complex with the repair factors TFIIH and XPG. Taken together, our results show the congruence of in vivo and in vitro data on nucleotide excision repair in humans.

scholarly journals Sequential Assembly of the Nucleotide Excision Repair Factors In Vivo

2001 ◽  
Vol 8 (1) ◽  
pp. 213-224 ◽  
Author(s):  
Marcel Volker ◽  
Martijn J Moné ◽  
Parimal Karmakar ◽  
Anneke van Hoffen ◽  
Wouter Schul ◽  
...  
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Nucleotide Excision ◽  
Sequential Assembly

scholarly journals Growth Retardation, Early Death, and DNA Repair Defects in Mice Deficient for the Nucleotide Excision Repair Enzyme XPF

2004 ◽  
Vol 24 (3) ◽  
pp. 1200-1205 ◽  
Author(s):  
Ming Tian ◽  
Reiko Shinkura ◽  
Nobuhiko Shinkura ◽  
Frederick W. Alt
Keyword(s):  
Dna Repair ◽  
Nucleotide Excision Repair ◽  
Uv Irradiation ◽  
Excision Repair ◽  
Genetic Defect ◽  
Growth Defect ◽  
Human Genetic Disease ◽  
Nucleotide Excision ◽  
Deficient Mice

ABSTRACT Xeroderma pigmentosum (XP) is a human genetic disease which is caused by defects in nucleotide excision repair. Since this repair pathway is responsible for removing UV irradiation-induced damage to DNA, XP patients are hypersensitive to sunlight and are prone to develop skin cancer. Based on the underlying genetic defect, the disease can be divided into the seven complementation groups XPA through XPG. XPF, in association with ERCC1, constitutes a structure-specific endonuclease that makes an incision 5′ to the photodamage. XPF-ERCC1 has also been implicated in both removal of interstrand DNA cross-links and homology-mediated recombination and in immunoglobulin class switch recombination (CSR). To study the function of XPF in vivo, we inactivated the XPF gene in mice. XPF-deficient mice showed a severe postnatal growth defect and died approximately 3 weeks after birth. Histological examination revealed that the liver of mutant animals contained abnormal cells with enlarged nuclei. Furthermore, embryonic fibroblasts defective in XPF are hypersensitive to UV irradiation and mitomycin C treatment. No defect in CSR was detected, suggesting that the nuclease is dispensable for this recombination process. These phenotypes are identical to those exhibited by the ERCC1-deficient mice, consistent with the functional association of the two proteins. The complex phenotype suggests that XPF-ERCC1 is involved in multiple DNA repair processes.

scholarly journals Recruitment of the Nucleotide Excision Repair Endonuclease XPG to Sites of UV-Induced DNA Damage Depends on Functional TFIIH

2006 ◽  
Vol 26 (23) ◽  
pp. 8868-8879 ◽  
Author(s):  
Angelika Zotter ◽  
Martijn S. Luijsterburg ◽  
Daniël O. Warmerdam ◽  
Shehu Ibrahim ◽  
Alex Nigg ◽  
...  
Keyword(s):  
Dna Damage ◽  
Nucleotide Excision Repair ◽  
Fluorescent Protein ◽  
Core Protein ◽  
Excision Repair ◽  
Mammalian Cell Lines ◽  
Nucleotide Excision ◽  
Green Fluorescent ◽  
Damaged Dna

ABSTRACT The structure-specific endonuclease XPG is an indispensable core protein of the nucleotide excision repair (NER) machinery. XPG cleaves the DNA strand at the 3′ side of the DNA damage. XPG binding stabilizes the NER preincision complex and is essential for the 5′ incision by the ERCC1/XPF endonuclease. We have studied the dynamic role of XPG in its different cellular functions in living cells. We have created mammalian cell lines that lack functional endogenous XPG and stably express enhanced green fluorescent protein (eGFP)-tagged XPG. Life cell imaging shows that in undamaged cells XPG-eGFP is uniformly distributed throughout the cell nucleus, diffuses freely, and is not stably associated with other nuclear proteins. XPG is recruited to UV-damaged DNA with a half-life of 200 s and is bound for 4 min in NER complexes. Recruitment requires functional TFIIH, although some TFIIH mutants allow slow XPG recruitment. Remarkably, binding of XPG to damaged DNA does not require the DDB2 protein, which is thought to enhance damage recognition by NER factor XPC. Together, our data present a comprehensive view of the in vivo behavior of a protein that is involved in a complex chromatin-associated process.

scholarly journals Centrin 2 Stimulates Nucleotide Excision Repair by Interacting with Xeroderma Pigmentosum Group C Protein

2005 ◽  
Vol 25 (13) ◽  
pp. 5664-5674 ◽  
Author(s):  
Ryotaro Nishi ◽  
Yuki Okuda ◽  
Eriko Watanabe ◽  
Toshio Mori ◽  
Shigenori Iwai ◽  
...  
Keyword(s):  
Nucleotide Excision Repair ◽  
Xeroderma Pigmentosum ◽  
Excision Repair ◽  
Physical Interaction ◽  
C Protein ◽  
Damage Recognition ◽  
C Terminus ◽  
Nucleotide Excision ◽  
Dna Damage Recognition

ABSTRACT Xeroderma pigmentosum group C (XPC) protein plays a key role in DNA damage recognition in global genome nucleotide excision repair (NER). The protein forms in vivo a heterotrimeric complex involving one of the two human homologs of Saccharomyces cerevisiae Rad23p and centrin 2, a centrosomal protein. Because centrin 2 is dispensable for the cell-free NER reaction, its role in NER has been unclear. Binding experiments with a series of truncated XPC proteins allowed the centrin 2 binding domain to be mapped to a presumed α-helical region near the C terminus, and three amino acid substitutions in this domain abrogated interaction with centrin 2. Human cell lines stably expressing the mutant XPC protein exhibited a significant reduction in global genome NER activity. Furthermore, centrin 2 enhanced the cell-free NER dual incision and damaged DNA binding activities of XPC, which likely require physical interaction between XPC and centrin 2. These results reveal a novel vital function for centrin 2 in NER, the potentiation of damage recognition by XPC.

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