Transcriptional Repression by Binding of Poly(ADP-ribose) Polymerase to Promoter Sequences

Soldatenkov, Viatcheslav A.; Chasovskikh, Sergey; Potaman, Vladimir N.; Трофимова, Ирина; Smulson, Mark E.; Dritschilo, Anatoly

doi:10.1074/jbc.m108551200

Cited by 104 publications

(112 citation statements)

References 41 publications

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“…Reports indicate that PARP-1, itself, can interact with gene promoters (16)(17)(18), and so we asked whether PARP-1 could be detected at the BRCA1 promoter by ChIP. We were able to detect association of PARP-1 with the BRCA1 promoter in untreated A549 cells (Fig.…”

Section: Resultsmentioning

confidence: 99%

Inhibition of poly(ADP-ribose) polymerase down-regulates BRCA1 and RAD51 in a pathway mediated by E2F4 and p130

Hegan¹,

Lü²,

Stachelek³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

186

111

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Inhibitors of poly(ADP-ribose) polymerase (PARP) are in clinical trials for cancer therapy, on the basis of the role of PARP in recruitment of base excision repair (BER) factors to sites of DNA damage. Here we show that PARP inhibition to block BER is toxic to hypoxic cancer cells, in which homology-dependent repair (HDR) is known to be down-regulated. However, we also report the unexpected finding that disruption of PARP, itself, either via chemical PARP inhibitors or siRNAs targeted to PARP-1, can inhibit HDR by suppressing expression of BRCA1 and RAD51, key factors in HDR of DNA breaks. Mechanistically, PARP inhibition was found to cause increased occupancy of the BRCA1 and RAD51 promoters by repressive E2F4/p130 complexes, a pathway prevented by expression of HPV E7, which disrupts p130 activity, or by siRNAs to knock down p130 expression. Functionally, disruption of p130 by E7 expression or by siRNA knockdown also reverses the cytotoxicity and radiosensitivity associated with PARP inhibition, suggesting that the down-regulation of BRCA1 and RAD51 is central to these effects. Direct measurement of HDR using a GFP-based assay demonstrates reduced HDR in cells treated with PARP inhibitors. This work identifies a mechanism by which PARP regulates DNA repair and suggests new strategies for combination cancer therapies.DNA repair | hypoxia P oly(ADP-ribose) polymerases (PARPs) comprise a family of enzymes that catalyze ADP ribosylation of a variety of cellular factors (1-4). PARP-1 is thought to play a key role in DNA repair, primarily by modifying chromatin factors at sites of DNA damage and thereby recruiting repair factors. Inhibitors of PARP have attracted interest for cancer therapy because cancer cells deficient in BRCA1 or BRCA2 due to inactivating mutations are sensitive to PARP inhibition (5-8). This has been attributed to the role of PARP in recruiting base excision repair (BER) factors that remove damaged bases and fix single-strand breaks (SSBs) (1). SSBs persisting into S-phase produce replication fork collapse, requiring BRCA1-and BRCA2-mediated homology-dependent repair (HDR) for resolution (5, 9, 10).In prior work, we found that hypoxia suppresses HDR in human cells via transcriptional down-regulation of BRCA1 and RAD51 (11-15). Hence, we hypothesized that cancer cells in hypoxia, with acquired deficiency in HDR, might have increased sensitivity to PARP inhibition. Work presented here confirms this hypothesis, showing that PARP inhibitors are more cytotoxic to hypoxic than to normoxic cells. Because hypoxia causes BRCA1 and RAD51 down-regulation by stimulating E2F4/p130 occupancy of the BRCA1 and RAD51 promoters, we asked whether disruption of p130 function via expression of human papillomavirus (HPV) E7 would reverse the sensitivity of hypoxic cells to PARP inhibition. We found that E7 expression, as predicted, does confer resistance to PARP inhibitors on hypoxic cells, but surprisingly, it also blocks the toxicity of PARP inhibition in normoxic cells.As a basis for this effect, we present eviden...

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Section: Resultsmentioning

confidence: 99%

Inhibition of poly(ADP-ribose) polymerase down-regulates BRCA1 and RAD51 in a pathway mediated by E2F4 and p130

Hegan¹,

Lü²,

Stachelek³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

186

111

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“…Similar binding of a single PARP-1 molecule to the end of a hairpin arm was observed in experiments with the three-way DNA junction model (Figs. 1a and 1b) (34). However, review of previous experiments using the three-way junction model and a cruciform structure suggests that the binding of a single PARP-1 molecule to the end of a hairpin arm was a rare event, while the binding of the PARP-1 monomer directly to the junction was not observed.…”

Section: Resultsmentioning

confidence: 98%

“…Extending our previous observations showing that PARP-1 can bind to hairpin containing regions in a three-way junction heteroduplex of DNA, we have focused on identifying the site of attachment of PARP-1 in this region (34).…”

Section: Resultsmentioning

confidence: 99%

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DNA transitions induced by binding of PARP‐1 to cruciform structures in supercoiled plasmids

et al. 2005

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Background: Poly(ADP-ribose)polymerase-1 (PARP-1) binds to single and double-stranded breaks in DNA, but less well known is its affinity for undamaged DNA. Previously, we have shown that PARP-1 also binds to the hairpin structures in DNA models. The mechanism underlying these interactions remains to be defined. Methods: We analyzed atomic force microscopy (AFM) images of complex of PARP-1 proteins with supercoiled plasmids containing cruciform structures. Using volume measurement analysis of molecules of PARP-1, we determined the numbers of PARP-1 molecules interacting with supercoiled DNA plasmids containing one cruciform structure. We also determined the extent of supercoiling of plasmids.

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“…On the other hand, PARP controls activation of a number of transcription factors, i.e. nuclear factor-kappa B, activator protein-1, signal transducer and activator of transcription-1, octamer-1 and p53 protein via direct binding, poly(ADPribosyl)ation or both [8,9]. This, in turn, up-regulates numerous genes [9,10], including those implicated in the pathogenesis of peripheral diabetic neuropathy (PDN), such as endothelin-1 [11], cyclooxygenase-2 [12,13] and inflammatory genes [14].…”

mentioning

confidence: 99%

Evaluation of orally active poly(ADP-ribose) polymerase inhibitor in streptozotocin-diabetic rat model of early peripheral neuropathy

Szabó

Pacher

et al. 2004

Diabetologia

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Aims/hypothesis. Poly(ADP-ribose) polymerase activation depletes NAD + and high-energy phosphates, activates protein kinase C, and affects gene expression in various tissues. This study was designed to characterise the effects of the potent, orally active poly(ADP-ribose) polymerase inhibitor PJ34 in the Wistar rat model of early diabetic neuropathy. Methods. Control and streptozotocin-diabetic rats were maintained with or without PJ34 treatment (30 mg·kg −1 ·day −1 ) for two weeks, after two weeks without treatment. Endoneurial blood flow was assessed by hydrogen clearance; metabolites and highenergy phosphates were assayed by enzymatic spectrofluorometric methods; and poly(ADP-ribose) was detected by immunohistochemistry.Results. Blood glucose concentrations were increased to a similar extent in untreated and PJ34-treated diabetic rats compared with controls. Intense poly(ADPribose) immunostaining was observed in the sciatic nerve of diabetic rats, but not in other groups. Final sciatic motor nerve conduction velocity and digital sensory nerve conduction velocity were reduced by 24% and 22% respectively in diabetic rats compared with controls (p<0.01 for both), and both were 98% corrected by PJ34 (p<0.01 vs diabetic group for both).In contrast, with PJ34 treatment, nerve blood flow showed a modest (17%) increase, and vascular conductance showed a tendency to increase. Free mitochondrial and cytosolic NAD + :NADH ratios, assessed from the glutamate and lactate dehydrogenase systems, phosphocreatine concentrations, and phosphocreatine:creatine ratios were decreased in diabetic rats and essentially normalised by PJ34. In both untreated and PJ34-treated diabetic rats, nerve glucose, sorbitol and fructose were increased to a similar extent. PJ34 did not affect any variables in control rats. Conclusions/interpretation. Short-term poly(ADP-ribose) polymerase inhibitor treatment reverses functional and metabolic abnormalities of early diabetic neuropathy. Complete normalisation of nerve blood flow is not required for correction of motor or sensory nerve conduction velocities, provided that a therapeutic agent can restore nerve energy state via direct action on Schwann cells.Keywords Energy state · Motor and sensory nerve conduction · Nerve blood flow · Oxidative and nitrosative stress · Peripheral diabetic neuropathy · PJ34 · Poly(ADP-ribose) polymerase · Rat · Sorbitol pathway of glucose metabolism · Streptozotocindiabetes

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Transcriptional Repression by Binding of Poly(ADP-ribose) Polymerase to Promoter Sequences

Cited by 104 publications

References 41 publications

Inhibition of poly(ADP-ribose) polymerase down-regulates BRCA1 and RAD51 in a pathway mediated by E2F4 and p130

Inhibition of poly(ADP-ribose) polymerase down-regulates BRCA1 and RAD51 in a pathway mediated by E2F4 and p130

DNA transitions induced by binding of PARP‐1 to cruciform structures in supercoiled plasmids

Evaluation of orally active poly(ADP-ribose) polymerase inhibitor in streptozotocin-diabetic rat model of early peripheral neuropathy

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