Both XPA and DNA polymerase eta are necessary for the repair of doxorubicin-induced DNA lesions

Moraes, Maria Carolina Strano; Quinet, Annabel; Carvalho, Helotônio; Guecheva, Temenouga Nikolova; Agnoletto, Mateus H.; Henriques, João Antônio Pêgas; Sarasin, Alain; Stary, Anne; Saffi, Jenifer; Menck, Carlos Frederico Martins

doi:10.1016/j.canlet.2011.09.019

Cited by 31 publications

(27 citation statements)

References 37 publications

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“…After 18 h, these samples were treated with 100 nM staurosporine (Sigma) or mock-treated with the same concentration of DMSO (zero time). Thereafter, the impedance was continuously measured according to the manufacturer's instructions and as previously described [59]. Three independent biological replicate experiments were performed, each with technical triplicates.…”

Section: Methodsmentioning

confidence: 99%

The Intronic Long Noncoding RNA ANRASSF1 Recruits PRC2 to the RASSF1A Promoter, Reducing the Expression of RASSF1A and Increasing Cell Proliferation

et al. 2013

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The down-regulation of the tumor-suppressor gene RASSF1A has been shown to increase cell proliferation in several tumors. RASSF1A expression is regulated through epigenetic events involving the polycomb repressive complex 2 (PRC2); however, the molecular mechanisms modulating the recruitment of this epigenetic modifier to the RASSF1 locus remain largely unknown. Here, we identify and characterize ANRASSF1, an endogenous unspliced long noncoding RNA (lncRNA) that is transcribed from the opposite strand on the RASSF1 gene locus in several cell lines and tissues and binds PRC2. ANRASSF1 is transcribed through RNA polymerase II and is 5′-capped and polyadenylated; it exhibits nuclear localization and has a shorter half-life compared with other lncRNAs that bind PRC2. ANRASSF1 endogenous expression is higher in breast and prostate tumor cell lines compared with non-tumor, and an opposite pattern is observed for RASSF1A. ANRASSF1 ectopic overexpression reduces RASSF1A abundance and increases the proliferation of HeLa cells, whereas ANRASSF1 silencing causes the opposite effects. These changes in ANRASSF1 levels do not affect the RASSF1C isoform abundance. ANRASSF1 overexpression causes a marked increase in both PRC2 occupancy and histone H3K27me3 repressive marks, specifically at the RASSF1A promoter region. No effect of ANRASSF1 overexpression was detected on PRC2 occupancy and histone H3K27me3 at the promoter regions of RASSF1C and the four other neighboring genes, including two well-characterized tumor suppressor genes. Additionally, we demonstrated that ANRASSF1 forms an RNA/DNA hybrid and recruits PRC2 to the RASSF1A promoter. Together, these results demonstrate a novel mechanism of epigenetic repression of the RASSF1A tumor suppressor gene involving antisense unspliced lncRNA, in which ANRASSF1 selectively represses the expression of the RASSF1 isoform overlapping the antisense transcript in a location-specific manner. In a broader perspective, our findings suggest that other non-characterized unspliced intronic lncRNAs transcribed in the human genome might contribute to a location-specific epigenetic modulation of genes.

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Section: Methodsmentioning

confidence: 99%

The Intronic Long Noncoding RNA ANRASSF1 Recruits PRC2 to the RASSF1A Promoter, Reducing the Expression of RASSF1A and Increasing Cell Proliferation

et al. 2013

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“…Not surprisingly, high POLH expression associated with significantly shorter survival, in a group of platinum treated non-small cell lung cancer patients (Ceppi et al, 2009). Moreover, the kinase inhibitor LY294002 enhanced the killing of cells deficient in Pol η, synergistically with the chemotherapeutic agent doxorubicin (Moraes et al, 2012) underscoring the ability of Pol η to regulate cellular response to these agents.…”

Section: Polhmentioning

confidence: 99%

Translesion DNA Polymerases and Cancer

Makridakis¹,

Reichardt²

2012

Front. Gene.

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DNA repair has been regarded as an important barrier to carcinogenesis. The newly discovered field of translesion synthesis (TLS) has made it apparent that mammalian cells need distinct polymerases to efficiently and accurately bypass DNA lesions. Perturbation of TLS polymerase activity by mutation, loss of expression, etc. is expected to result in the accumulation of mutations in cells exposed to specific carcinogens. Furthermore, several TLS polymerases can modulate cellular sensitivity to chemotherapeutic agents. TLS genes and TLS gene variations may thus be attractive pharmacologic and/or pharmacogenetic targets. We review herein current data with regards to the potential contribution of the primary TLS polymerase genes to cancer, their interaction with pharmacologic agents, and identify areas of interest for further research.

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“…17-19 Another way of acquiring resistance to genotoxic agents is through pathways that allow the cell to tolerate the DNA damage by performing translesion DNA synthesis (TLS) past the offending lesion instead of performing repair. 20-22 DNA damage tolerance pathways are utilized when DNA adducts are not repaired prior to S-phase or when the repair mechanism requires a specialized polymerase to complete the repair process (e.g. nucleotide excision repair of cross-linked DNA).…”

Section: Introductionmentioning

confidence: 99%

“…16, 35-39 Importantly, recent studies have shown that Y-family polymerases, particularly human DNA polymerase eta (hpol η), participate in mechanisms that promote resistance to anti-cancer treatments, such as cisplatin and doxorubicin. 20-22 We have attempted to identify novel inhibitors of DNA polymerase activity by utilizing a previously reported fluorescence-based assay that measures polymerase-catalyzed strand displacement, which is dependent upon nucleotidyl transfer by the enzyme. 40 We screened a targeted collection of over 300 compounds that were designed to target nucleic acid-interacting proteins and enzymes.…”

Section: Introductionmentioning

confidence: 99%

N-Aroyl Indole Thiobarbituric Acids as Inhibitors of DNA Repair and Replication Stress Response Polymerases

Coggins

Maddukuri²,

Penthala³

et al. 2013

ACS Chem. Biol.

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Using a robust and quantitative assay, we have identified a novel class of DNA polymerase inhibitors that exhibits some specificity against an enzyme involved in resistance to anti-cancer drugs, namely human DNA polymerase eta (hpol η). In our initial screen, we identified the indole thiobarbituric acid (ITBA) derivative 5-((1-(2-bromobenzoyl)-5-chloro-1H-indol-3-yl)methylene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (ITBA-12) as an inhibitor of the Y-family DNA member hpol η, an enzyme that has been associated with increased resistance to cisplatin and doxorubicin treatments. An additional seven DNA polymerases from different sub-families were tested for inhibition by ITBA-12. Hpol η was the most potently inhibited enzyme (30 ± 3 μM), with hpol β, hpol γ and hpol κ exhibiting comparable but higher IC50 values of 41 ± 24 μM, 49 ± 6 μM and 59 ± 11 μM, respectively. The other polymerases tested had IC50 values closer to 80 μM. Steady-state kinetic analysis was used to investigate the mechanism of polymerase inhibition by ITBA-12. Based on changes in the Michaelis constant, it was determined that ITBA-12 acts as an allosteric (or partial) competitive inhibitor of dNTP binding. The parent ITBA scaffold was modified to produce 20 derivatives and establish structure-activity relationships by testing for inhibition of hpol η. Two compounds with N-naphthoyl Ar-substituents, ITBA-16 and ITBA-19, were both found to have improved potency against hpol η with IC50 values of 16 ± 3 μM and 17 ± 3 μM, respectively. Moreover, the specificity of ITBA-16 was improved relative to ITBA-12. The presence of a chloro substituent at position 5 on the indole ring appears to be crucial for effective inhibition of hpol η, with the indole N-1-naphthoyl and N-2-naphthoyl analogs being the most potent inhibitors of hpol η. These results provide a framework from which second-generation ITBA derivatives may be developed against specialized polymerases that are involved in mechanisms of radio- and chemo-resistance.

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Both XPA and DNA polymerase eta are necessary for the repair of doxorubicin-induced DNA lesions

Cited by 31 publications

References 37 publications

The Intronic Long Noncoding RNA ANRASSF1 Recruits PRC2 to the RASSF1A Promoter, Reducing the Expression of RASSF1A and Increasing Cell Proliferation

The Intronic Long Noncoding RNA ANRASSF1 Recruits PRC2 to the RASSF1A Promoter, Reducing the Expression of RASSF1A and Increasing Cell Proliferation

Translesion DNA Polymerases and Cancer

N-Aroyl Indole Thiobarbituric Acids as Inhibitors of DNA Repair and Replication Stress Response Polymerases

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