Key Spec Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|Vrt||ICC, IF, WB, ChIP||M||Purified||Monoclonal Antibody|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||Maintain for 1 year at 2 to 8°C from date of shipment. For maximum recovery of product, centrifuge the original vial prior to removing the cap.|
|Material Size||200 µg|
|Reference overview||Application||Species||Pub Med ID|
|In vivo measurement of dose distribution in patients' lymphocytes: helical tomotherapy versus step-and-shoot IMRT in prostate cancer.|
Zwicker, F; Swartman, B; Roeder, F; Sterzing, F; Hauswald, H; Thieke, C; Weber, KJ; Huber, PE; Schubert, K; Debus, J; Herfarth, K
Journal of radiation research 56 239-47 2015
In radiotherapy, in vivo measurement of dose distribution within patients' lymphocytes can be performed by detecting gamma-H2AX foci in lymphocyte nuclei. This method can help in determining the whole-body dose. Options for risk estimations for toxicities in normal tissue and for the incidence of secondary malignancy are still under debate. In this investigation, helical tomotherapy (TOMO) is compared with step-and-shoot IMRT (SSIMRT) of the prostate gland by measuring the dose distribution within patients' lymphocytes. In this prospective study, blood was taken from 20 patients before and 10 min after their first irradiation fraction for each technique. The isolated leukocytes were fixed 2 h after radiation. DNA double-stranded breaks in lymphocyte nuclei were stained immunocytochemically using anti-gamma-H2AX antibodies. Gamma-H2AX foci distribution in lymphocytes was determined for each patient. Using a calibration line, dose distributions in patients' lymphocytes were determined by studying the gamma-H2AX foci distribution, and these data were used to generate a cumulative dose-lymphocyte histogram (DLH). Measured in vivo (DLH), significantly fewer lymphocytes indicated low-dose exposure (less than 40% of the applied dose) during TOMO compared with SSIMRT. The dose exposure range, between 45 and 100%, was equal with both radiation techniques. The mean number of gamma-H2AX foci per lymphocyte was significantly lower in the TOMO group compared with the SSIMRT group. In radiotherapy of the prostate gland, TOMO generates a smaller fraction of patients' lymphocytes with low-dose exposure relative to the whole body compared with SSIMRT. Differences in the constructional buildup of the different linear accelerator systems, e.g. the flattening filter, may be the cause thereof. The influence of these methods on the incidence of secondary malignancy should be investigated in further studies.
|Co-visualization of DNA damage and ion traversals in live mammalian cells using a fluorescent nuclear track detector.|
Kodaira, S; Konishi, T; Kobayashi, A; Maeda, T; Ahmad, TA; Yang, G; Akselrod, MS; Furusawa, Y; Uchihori, Y
Journal of radiation research 56 360-5 2015
The geometric locations of ion traversals in mammalian cells constitute important information in the study of heavy ion-induced biological effect. Single ion traversal through a cellular nucleus produces complex and massive DNA damage at a nanometer level, leading to cell inactivation, mutations and transformation. We present a novel approach that uses a fluorescent nuclear track detector (FNTD) for the simultaneous detection of the geometrical images of ion traversals and DNA damage in single cells using confocal microscopy. HT1080 or HT1080-53BP1-GFP cells were cultured on the surface of a FNTD and exposed to 5.1-MeV/n neon ions. The positions of the ion traversals were obtained as fluorescent images of a FNTD. Localized DNA damage in cells was identified as fluorescent spots of γ-H2AX or 53BP1-GFP. These track images and images of damaged DNA were obtained in a short time using a confocal laser scanning microscope. The geometrical distribution of DNA damage indicated by fluorescent γ-H2AX spots in fixed cells or fluorescent 53BP1-GFP spots in living cells was found to correlate well with the distribution of the ion traversals. This method will be useful for evaluating the number of ion hits on individual cells, not only for micro-beam but also for random-beam experiments.
|TIMELESS Forms a Complex with PARP1 Distinct from Its Complex with TIPIN and Plays a Role in the DNA Damage Response.|
Young, LM; Marzio, A; Perez-Duran, P; Reid, DA; Meredith, DN; Roberti, D; Star, A; Rothenberg, E; Ueberheide, B; Pagano, M
Cell reports 13 451-9 2015
PARP1 is the main sensor of single- and double-strand breaks in DNA and, in building chains of poly(ADP-ribose), promotes the recruitment of many downstream signaling and effector proteins involved in the DNA damage response (DDR). We show a robust physical interaction between PARP1 and the replication fork protein TIMELESS, distinct from the known TIMELESS-TIPIN complex, which activates the intra-S phase checkpoint. TIMELESS recruitment to laser-induced sites of DNA damage is dependent on its binding to PARP1, but not PARP1 activity. We also find that the PARP1-TIMELESS complex contains a number of established PARP1 substrates, and TIMELESS mutants unable to bind PARP1 are impaired in their ability to bind PARP1 substrates. Further, PARP1 binding to certain substrates and their recruitment to DNA damage lesions is impaired by TIMELESS knockdown, and TIMELESS silencing significantly impairs DNA double-strand break repair. We hypothesize that TIMELESS cooperates in the PARP1-mediated DDR.
|HMGB1 facilitates repair of mitochondrial DNA damage and extends the lifespan of mutant ataxin-1 knock-in mice.|
Ito, H; Fujita, K; Tagawa, K; Chen, X; Homma, H; Sasabe, T; Shimizu, J; Shimizu, S; Tamura, T; Muramatsu, S; Okazawa, H
EMBO molecular medicine 7 78-101 2015
Mutant ataxin-1 (Atxn1), which causes spinocerebellar ataxia type 1 (SCA1), binds to and impairs the function of high-mobility group box 1 (HMGB1), a crucial nuclear protein that regulates DNA architectural changes essential for DNA damage repair and transcription. In this study, we established that transgenic or virus vector-mediated complementation with HMGB1 ameliorates motor dysfunction and prolongs lifespan in mutant Atxn1 knock-in (Atxn1-KI) mice. We identified mitochondrial DNA damage repair by HMGB1 as a novel molecular basis for this effect, in addition to the mechanisms already associated with HMGB1 function, such as nuclear DNA damage repair and nuclear transcription. The dysfunction and the improvement of mitochondrial DNA damage repair functions are tightly associated with the exacerbation and rescue, respectively, of symptoms, supporting the involvement of mitochondrial DNA quality control by HMGB1 in SCA1 pathology. Moreover, we show that the rescue of Purkinje cell dendrites and dendritic spines by HMGB1 could be downstream effects. Although extracellular HMGB1 triggers inflammation mediated by Toll-like receptor and receptor for advanced glycation end products, upregulation of intracellular HMGB1 does not induce such side effects. Thus, viral delivery of HMGB1 is a candidate approach by which to modify the disease progression of SCA1 even after the onset.
|SETD2 loss-of-function promotes renal cancer branched evolution through replication stress and impaired DNA repair.|
Kanu, N; Grönroos, E; Martinez, P; Burrell, RA; Yi Goh, X; Bartkova, J; Maya-Mendoza, A; Mistrík, M; Rowan, AJ; Patel, H; Rabinowitz, A; East, P; Wilson, G; Santos, CR; McGranahan, N; Gulati, S; Gerlinger, M; Birkbak, NJ; Joshi, T; Alexandrov, LB; Stratton, MR; Powles, T; Matthews, N; Bates, PA; Stewart, A; Szallasi, Z; Larkin, J; Bartek, J; Swanton, C
Oncogene 34 5699-708 2015
Defining mechanisms that generate intratumour heterogeneity and branched evolution may inspire novel therapeutic approaches to limit tumour diversity and adaptation. SETD2 (Su(var), Enhancer of zeste, Trithorax-domain containing 2) trimethylates histone-3 lysine-36 (H3K36me3) at sites of active transcription and is mutated in diverse tumour types, including clear cell renal carcinomas (ccRCCs). Distinct SETD2 mutations have been identified in spatially separated regions in ccRCC, indicative of intratumour heterogeneity. In this study, we have addressed the consequences of SETD2 loss-of-function through an integrated bioinformatics and functional genomics approach. We find that bi-allelic SETD2 aberrations are not associated with microsatellite instability in ccRCC. SETD2 depletion in ccRCC cells revealed aberrant and reduced nucleosome compaction and chromatin association of the key replication proteins minichromosome maintenance complex component (MCM7) and DNA polymerase δ hindering replication fork progression, and failure to load lens epithelium-derived growth factor and the Rad51 homologous recombination repair factor at DNA breaks. Consistent with these data, we observe chromosomal breakpoint locations are biased away from H3K36me3 sites in SETD2 wild-type ccRCCs relative to tumours with bi-allelic SETD2 aberrations and that H3K36me3-negative ccRCCs display elevated DNA damage in vivo. These data suggest a role for SETD2 in maintaining genome integrity through nucleosome stabilization, suppression of replication stress and the coordination of DNA repair.
|Ablation of the p16(INK4a) tumour suppressor reverses ageing phenotypes of klotho mice.|
Sato, S; Kawamata, Y; Takahashi, A; Imai, Y; Hanyu, A; Okuma, A; Takasugi, M; Yamakoshi, K; Sorimachi, H; Kanda, H; Ishikawa, Y; Sone, S; Nishioka, Y; Ohtani, N; Hara, E
Nature communications 6 7035 2015
The p16(INK4a) tumour suppressor has an established role in the implementation of cellular senescence in stem/progenitor cells, which is thought to contribute to organismal ageing. However, since p16(INK4a) knockout mice die prematurely from cancer, whether p16(INK4a) reduces longevity remains unclear. Here we show that, in mutant mice homozygous for a hypomorphic allele of the α-klotho ageing-suppressor gene (kl(kl/kl)), accelerated ageing phenotypes are rescued by p16(INK4a) ablation. Surprisingly, this is due to the restoration of α-klotho expression in kl(kl/kl) mice and does not occur when p16(INK4a) is ablated in α-klotho knockout mice (kl(-/-)), suggesting that p16(INK4a) is an upstream regulator of α-klotho expression. Indeed, p16(INK4a) represses α-klotho promoter activity by blocking the functions of E2Fs. These results, together with the observation that the expression levels of p16(INK4a) are inversely correlated with those of α-klotho throughout ageing, indicate that p16(INK4a) plays a previously unrecognized role in downregulating α-klotho expression during ageing.
|Resveratrol Induced Premature Senescence Is Associated with DNA Damage Mediated SIRT1 and SIRT2 Down-Regulation.|
Kilic Eren, M; Kilincli, A; Eren, Ö
PloS one 10 e0124837 2015
The natural polyphenolic compound resveratrol (3,4,5-trihydroxy-trans-stilbene) has broad spectrum health beneficial activities including antioxidant, anti-inflammatory, anti-aging, anti-cancer, cardioprotective, and neuroprotective effects. Remarkably, resveratrol also induces apoptosis and cellular senescence in primary and cancer cells. Resveratrol's anti-aging effects both in vitro and in vivo attributed to activation of a (NAD)-dependent histone deacetylase family member sirtuin-1 (SIRT1) protein. In mammals seven members (SIRT1-7) of sirtuin family have been identified. Among those, SIRT1 is the most extensively studied with perceptive effects on mammalian physiology and suppression of the diseases of aging. Yet no data has specified the role of sirtuins, under conditions where resveratrol treatment induces senescence. Current study was undertaken to investigate the effects of resveratrol in human primary dermal fibroblasts (BJ) and to clarify the role of sirtuin family members in particular SIRT1 and SIRT2 that are known to be involved in cellular stress responses and cell cycle, respectively. Here, we show that resveratrol decreases proliferation of BJ cells in a time and dose dependent manner. In addition the increase in senescence associated β-galactosidase (SA-β-gal) activity and methylated H3K9-me indicate the induction of premature senescence. A significant increase in phosphorylation of γ-H2AX, a surrogate of DNA double strand breaks, as well as in levels of p53, p21CIP1 and p16INK4A is also detected. Interestingly, at concentrations where resveratrol induced premature senescence we show a significant decrease in SIRT1 and SIRT2 levels by Western Blot and quantitative RT-PCR analysis. Conversely inhibition of SIRT1 and SIRT2 via siRNA or sirtinol treatment also induced senescence in BJ fibroblasts associated with increased SA-β-gal activity, γ-H2AX phosphorylation and p53, p21CIP1 and p16INK4A levels. Interestingly DNA damaging agent doxorubicin also induced senescence in BJ fibroblasts associated with decreased SIRT1/2 levels. In conclusion our data reveal that resveratrol induced premature senescence is associated with SIRT1 and SIRT2 down regulation in human dermal fibroblasts. Here we suggest that the concomitant decline in SIRT1/2 expression in response to resveratrol treatment may be a cause for induction of senescence, which is most likely mediated by a regulatory mechanism activated by DNA damage response.
|Dexamethasone acts as a radiosensitizer in three astrocytoma cell lines via oxidative stress.|
Redox biology 5 388-97 2015
Glucocorticoids (GCs), which act on stress pathways, are well-established in the co-treatment of different kinds of tumors; however, the underlying mechanisms by which GCs act are not yet well elucidated. As such, this work investigates the role of glucocorticoids, specifically dexamethasone (DEXA), in the processes referred to as DNA damage and DNA damage response (DDR), establishing a new approach in three astrocytomas cell lines (CT2A, APP.PS1 L.1 and APP.PS1 L.3). The results show that DEXA administration increased the basal levels of gamma-H2AX foci, keeping them higher 4h after irradiation (IR) of the cells, compared to untreated cells. This means that DEXA might cause increased radiosensitivity in these cell lines. On the other hand, DEXA did not have an apparent effect on the formation and disappearance of the 53BP1 foci. Furthermore, it was found that DEXA administered 2h before IR led to a radical change in DNA repair kinetics, even DEXA does not affect cell cycle. It is important to highlight that DEXA produced cell death in these cell lines compared to untreated cells. Finally and most important, the high levels of gamma-H2AX could be reversed by administration of ascorbic acid, a potent blocker of reactive oxygen species, suggesting that DEXA acts by causing DNA damage via oxidative stress. These exiting findings suggest that DEXA might promote radiosensitivity in brain tumors, specifically in astrocytoma-like tumors.
|DNA ligase III acts as a DNA strand break sensor in the cellular orchestration of DNA strand break repair.|
Abdou, I; Poirier, GG; Hendzel, MJ; Weinfeld, M
Nucleic acids research 43 875-92 2015
In the current model of DNA SSBR, PARP1 is regarded as the sensor of single-strand breaks (SSBs). However, biochemical studies have implicated LIG3 as another possible SSB sensor. Using a laser micro-irradiation protocol that predominantly generates SSBs, we were able to demonstrate that PARP1 is dispensable for the accumulation of different single-strand break repair (SSBR) proteins at sites of DNA damage in live cells. Furthermore, we show in live cells for the first time that LIG3 plays a role in mediating the accumulation of the SSBR proteins XRCC1 and PNKP at sites of DNA damage. Importantly, the accumulation of LIG3 at sites of DNA damage did not require the BRCT domain-mediated interaction with XRCC1. We were able to show that the N-terminal ZnF domain of LIG3 plays a key role in the enzyme's SSB sensing function. Finally, we provide cellular evidence that LIG3 and not PARP1 acts as the sensor for DNA damage caused by the topoisomerase I inhibitor, irinotecan. Our results support the existence of a second damage-sensing mechanism in SSBR involving the detection of nicks in the genome by LIG3.
|SWI/SNF complexes are required for full activation of the DNA-damage response.|
Smith-Roe, SL; Nakamura, J; Holley, D; Chastain, PD; Rosson, GB; Simpson, DA; Ridpath, JR; Kaufman, DG; Kaufmann, WK; Bultman, SJ
Oncotarget 6 732-45 2015
SWI/SNF complexes utilize BRG1 (also known as SMARCA4) or BRM (also known as SMARCA2) as alternative catalytic subunits with ATPase activity to remodel chromatin. These chromatin-remodeling complexes are required for mammalian development and are mutated in ~20% of all human primary tumors. Yet our knowledge of their tumor-suppressor mechanism is limited. To investigate the role of SWI/SNF complexes in the DNA-damage response (DDR), we used shRNAs to deplete BRG1 and BRM and then exposed these cells to a panel of 6 genotoxic agents. Compared to controls, the shRNA knockdown cells were hypersensitive to certain genotoxic agents that cause double-strand breaks (DSBs) associated with stalled/collapsed replication forks but not to ionizing radiation-induced DSBs that arise independently of DNA replication. These findings were supported by our analysis of DDR kinases, which demonstrated a more prominent role for SWI/SNF in the activation of the ATR-Chk1 pathway than the ATM-Chk2 pathway. Surprisingly, γH2AX induction was attenuated in shRNA knockdown cells exposed to a topoisomerase II inhibitor (etoposide) but not to other genotoxic agents including IR. However, this finding is compatible with recent studies linking SWI/SNF with TOP2A and TOP2BP1. Depletion of BRG1 and BRM did not result in genomic instability in a tumor-derived cell line but did result in nucleoplasmic bridges in normal human fibroblasts. Taken together, these results suggest that SWI/SNF tumor-suppressor activity involves a role in the DDR to attenuate replicative stress and genomic instability. These results may also help to inform the selection of chemotherapeutics for tumors deficient for SWI/SNF function.
|Advancing cancer research: From hallmarks & biomarkers to tumor microenvironment progression|
|Western Blotting Tools|
|White Paper - The Message in the Marks: Deciphering Cancer Epigenetics|
|How can I check the phosphospecificity of my antibody once my protein is already immobilized on a membrane?||You can check for the phosphospecificity of your antibody using Lambda Protein Phosphatase. Simply perform SDS-polyacrylamide gel electrophoresis (SDS-PAGE) on a cell lysate and transfer the proteins to your membrane of choice. Wash the blotted nitrocellulose twice with water. Block the blotted nitrocellulose in freshly prepared TBS containing 1% bovine serum albumin (BSA) and 0.1% Triton X-100 for 1 hour at 20-25°C with constant agitation. Incubate the nitrocellulose in TBS containing 1% bovine serum albumin (BSA), 0.1% Triton X-100 and 2 mM MnCl2, and where dephosphorylation of proteins is desirable, 400 U/ml Lambda Protein Phosphatase for two hours at room temperature, or overnight at 4°C. After incubation, wash the nitrocellulose in PBS-0.1% Tween 20 for 3-5 minutes. Rinse the nitrocellulose in 4-5 changes of water. Continue with your western blotting assay.|