David S Schrump

National Cancer Institute (USA), 베서스다, Maryland, United States

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Publications (130)706.6 Total impact

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    ABSTRACT: Although microRNAs (miRs) have been implicated in the pathogenesis of various human malignancies, limited information is available regarding mechanisms by which these noncoding RNAs contribute to initiation and progression of tobacco-induced esophageal cancers. In this study, array and quantitative reverse transcriptase-PCR techniques were used to examine miR expression in immortalized esophageal epithelia (IEE) and esophageal adenocarcinoma (EAC) cells cultured in normal media with or without cigarette smoke condensate (CSC). Under relevant exposure conditions, CSC significantly decreased miR-217 expression in these cells. Endogenous levels of miR-217 expression in cultured EAC cells (EACC)/primary EACs were significantly lower than those observed in IEE/ paired normal esophageal tissues. RNA crosslink immunoprecipitation, quantitative reverse transcriptase-PCR (qRT-PCR) and immunoblot experiments demonstrated direct interaction of miR-217 with kallikrein 7 (KLK7), encoding a putative oncogene not previously implicated in EAC. Repression of miR-217 correlated with increased levels of KLK7 in primary EACs, particularly those from smokers. Chromatin and methylated DNA immunoprecipitation experiments demonstrated that CSC-mediated repression of miR-217 coincided with DNMT3b-dependent hypermethylation and decreased occupancy of nuclear factor 1 within the miR-217 genomic locus. Deoxyazacytidine induced miR-217 expression and downregulated KLK7 in EACC; deoxyazacytidine also attenuated CSC-mediated miR-217 repression and upregulation of KLK7 in IEE and EACC. Overexpression of miR-217 significantly decreased, whereas overexpression of KLK7 increased proliferation, invasion and tumorigenicity of EACC. Collectively, these data demonstrate that epigenetic repression of miR-217 contributes to the pathogenesis of EAC via upregulation of KLK7 and suggest that restoration of miR-217 expression may be a novel treatment strategy for these malignancies.Oncogene advance online publication, 23 February 2015; doi:10.1038/onc.2015.10.
    Oncogene 02/2015; DOI:10.1038/onc.2015.10 · 8.56 Impact Factor
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    ABSTRACT: Context: Ectopic ACTH/CRH syndrome is a rare cause of Cushing syndrome (CS), especially in children. The localization, work-up, and management of ACTH/CRH secreting tumors are discussed. Setting: A retrospective study was conducted of patients under 21 years of age evaluated at the National Institutes of Health (NIH) for CS and diagnosed with ectopic ACTH/CRH secreting tumors during the period 2009-2014. Patients: Seven patients with ectopic ACTH/CRH syndrome are included in this study, median age 13.6 years (range 1-21), 3 female. Measurements: Clinical, biochemical, radiological features, treatment and histological findings are described. Results: Seven patients were found to have ACTH/CRH secreting tumors with neuroendocrine features. The site of the primary lesion varied: pancreas (3), thymus (2), liver (1), right lower pulmonary lobe (1). Patients underwent biochemical evaluation for CS, including diurnal serum cortisol and ACTH levels, urinary free cortisol levels (UFC), and CRH stimulation tests. All patients underwent radiological investigations including MRI, CT and PET scan; imaging with octreotide and 68gallium DOTA-TATE scans were performed in individual cases. Five patients underwent inferior petrosal sinus sampling; 4 patients had sampling for ACTH levels from additional sites. Three patients underwent transsphenoidal surgery (TSS), and 3 patients required bilateral adrenalectomy. 3 patients (43%) died due to metastatic disease, demonstrating the high mortality rate. One of the unique findings in these seven patients is that in each case, their neuroendocrine tumors were ultimately proven to be co-secreting ACTH and CRH. This explains the enigmatic presentation, in which 3 patients initially thought to have Cushing's disease (CD) with corresponding pituitary hyperplasia underwent TSS prior to the correct localization of the causative tumor. Conclusions: Ectopic ACTH/CRH co-secreting tumors are extremely rare in children and adolescents. Its diagnosis is frequently missed and is sometimes confused with CD due to the effect of CRH on the pituitary.
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    ABSTRACT: Mithramycin is a neoplastic antibiotic synthesized by various Streptomyces bacteria. It is under investigation as a chemotherapeutic treatment for a wide variety of cancers. Ongoing and forthcoming clinical trials will require pharmacokinetic analysis of mithramycin in humans, both to see if target concentrations are achieved and to optimize dosing and correlate outcomes (response/toxicity) with pharmacokinetics. Two published methods for mithramycin quantitation exist, but both are immunoassays that lack current bioanalytical standards of selectivity and sensitivity. To provide an upgraded and more widely applicable assay, a UPLC-MS/MS method for quantitation of mithramycin in human plasma was developed. Solid-phase extraction allowed for excellent recoveries (>90%) necessary for high throughput analyses on sensitive instrumentation. However, a ∼55% reduction in analyte signal was observed as a result of plasma matrix effects. Mithramycin and the internal standard chromomycin were separated on a Waters Acquity BEH C18 column (2.1×50mm, 1.7μm) and detected using electrospray ionization operated in the negative mode at mass transitions m/z 1083.5→268.9 and 1181.5→269.0, respectively, on an AB Sciex QTrap 5500. The assay range was 0.5-500ng/mL and proved to be linear (r(2)>0.996), accurate (≤10% deviation), and precise (CV<15%). Mithramycin was stable in plasma at room temperature for 24h, as well as through three freeze-thaw cycles. This method was subsequently used to quantitate mithramycin plasma concentrations from patients enrolled on two clinical trials at the NCI.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 09/2014; 970C:95-101. DOI:10.1016/j.jchromb.2014.08.021 · 2.78 Impact Factor
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    ABSTRACT: Purpose:This phase I/II study sought to determine the safety and maximum-tolerated dose (MTD) of a novel schedule of belinostat, a histone deacetylase inhibitor administered prior to and in combination with cisplatin (P), doxorubicin (A) and cyclophosphamide (C) in thymic epithelial tumors (TET). Anti-tumor activity, pharmacokinetics, and biomarkers of response were also assessed. Experimental Design:Patients with advanced, unresectable TET received increasing doses of belinostat as a continuous intravenous infusion over 48-hours with chemotherapy in 3-week cycles. In phase II, belinostat at the MTD was used. Results:26 patients were enrolled (thymoma: 12; thymic carcinoma: 14). Dose-limiting toxicities at 2000 mg/m2 belinostat were grade 3 nausea and diarrhea and grade 4 neutropenia and thrombocytopenia, respectively, in two patients. 24 patients were treated at the MTD of 1000 mg/m2 with chemotherapy (P 50 mg/m2 on day 2; A 25 mg/m2 on days 2, 3; C 500 mg/m2 on day 3). Objective response rates in thymoma and thymic carcinoma were 64% [95% confidence interval: 30.8%-89.1%] and 21% (4.7%-50.8%) respectively. Modulation of pharmacodynamic markers of HDAC-inhibition and declines in regulatory T cell (Tregs) and exhausted CD8+ T cell populations were observed. Decline in Tregs was associated with response (p=0.0041) and progression-free survival (p=0.021). Declines in TIM-3+ CD8+T cells were larger in responders than non-responders (p=0.049). Conclusions:This study identified the MTD of belinostat in combination with PAC and indicates that the combination is active and feasible in TETs. Immunomodulatory effects on regulatory T cells and TIM3+ CD8+ T cells warrant further study.
    Clinical Cancer Research 09/2014; 20(21). DOI:10.1158/1078-0432.CCR-14-0968 · 8.19 Impact Factor
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    ABSTRACT: BackgroundA prospective randomized trial was conducted to compare the impact of systemic chemotherapy versus multi-modality therapy (complete cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), and systemic chemotherapy) on overall survival (OS) in patients with gastric carcinomatosis.Methods Patients with measurable metastatic gastric adenocarcinoma involving the peritoneum, and resectable to “no evidence of disease” were randomized to gastrectomy, metastasectomy, HIPEC, and systemic FOLFOXIRI (GYMS arm) or FOLFOXIRI alone (SA arm).ResultsSeventeen patients were enrolled (16 evaluable); 7 of 9 patients in the multi-modality GYMS arm achieved complete cytoreduction (CCR0). Median OS was 11.3 months in the GYMS arm and 4.3 months in the SA arm. Four patients in the GYMS arm survived >12 months, 2 patients close to 2 years at last follow-up, and 1 patient more than 4 years, with 2 of these patients still alive. No patient in the SA arm lived beyond 11 months. All patients surviving beyond 12 months in the surgery arm achieved complete cytoreduction and had an initial Peritoneal Cancer Index (PCI) of ≤15.Conclusion Maximal cytoreductive surgery combined with regional (HIPEC) and systemic chemotherapy in selected patients with gastric carcinomatosis and limited disease burden can achieve prolonged survival. J. Surg. Oncol. © 2014 Wiley Periodicals, Inc.
    Journal of Surgical Oncology 09/2014; 110(3). DOI:10.1002/jso.23633 · 2.84 Impact Factor
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    ABSTRACT: Although implicated in the pathogenesis of several chronic inflammatory disorders and hematologic malignancies, telomerase mutations have not been thoroughly characterized in human cancers. The present study was performed to examine the frequency and potential clinical relevance of telomerase mutations in esophageal carcinomas.
    PLoS ONE 07/2014; 9(7):e101010. DOI:10.1371/journal.pone.0101010 · 3.53 Impact Factor
  • David S Schrump
    The Annals of thoracic surgery 03/2014; 97(3):1045. DOI:10.1016/j.athoracsur.2013.12.031 · 3.45 Impact Factor
  • Cancer Research 08/2013; 73(8 Supplement):3071-3071. DOI:10.1158/1538-7445.AM2013-3071 · 9.28 Impact Factor
  • Cancer Research 08/2013; 73(8 Supplement):675-675. DOI:10.1158/1538-7445.AM2013-675 · 9.28 Impact Factor
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    ABSTRACT: Here, we report that kinase-dead IKKα knockin mice develop spontaneous lung squamous cell carcinomas (SCCs) associated with IKKα downregulation and marked pulmonary inflammation. IKKα reduction upregulated the expression of p63, Trim29, and keratin 5 (K5), which serve as diagnostic markers for human lung SCCs. IKKα(low)K5(+)p63(hi) cell expansion and SCC formation were accompanied by inflammation-associated deregulation of oncogenes, tumor suppressors, and stem cell regulators. Reintroducing transgenic K5.IKKα, depleting macrophages, and reconstituting irradiated mutant animals with wild-type bone marrow (BM) prevented SCC development, suggesting that BM-derived IKKα mutant macrophages promote the transition of IKKα(low)K5(+)p63(hi) cells to tumor cells. This mouse model resembles human lung SCCs, sheds light on the mechanisms underlying lung malignancy development, and identifies targets for therapy of lung SCCs.
    Cancer cell 04/2013; 23(4):527-540. DOI:10.1016/j.ccr.2013.03.009 · 25.29 Impact Factor
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    ABSTRACT: MicroRNAs are critical mediators of stem cell pluripotency, differentiation, and malignancy. Limited information exists regarding microRNA alterations that facilitate initiation and progression of human lung cancers. In this study, array techniques were used to evaluate microRNA expression in normal human respiratory epithelia and lung cancer cells cultured in the presence or absence of cigarette smoke condensate (CSC). Under relevant exposure conditions, CSC significantly repressed miR-487b. Subsequent experiments demonstrated that miR-487b directly targeted SUZ12, BMI1, WNT5A, MYC, and KRAS. Repression of miR-487b correlated with overexpression of these targets in primary lung cancers and coincided with DNA methylation, de novo nucleosome occupancy, and decreased H2AZ and TCF1 levels within the miR-487b genomic locus. Deoxy-azacytidine derepressed miR-487b and attenuated CSC-mediated silencing of miR-487b. Constitutive expression of miR-487b abrogated Wnt signaling, inhibited in vitro proliferation and invasion of lung cancer cells mediated by CSC or overexpression of miR-487b targets, and decreased growth and metastatic potential of lung cancer cells in vivo. Collectively, these findings indicate that miR-487b is a tumor suppressor microRNA silenced by epigenetic mechanisms during tobacco-induced pulmonary carcinogenesis and suggest that DNA demethylating agents may be useful for activating miR-487b for lung cancer therapy.
    The Journal of clinical investigation 03/2013; 123(3):1241-61. DOI:10.1172/JCI61271 · 15.39 Impact Factor
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    ABSTRACT: INTRODUCTION:: Although thymic epithelial tumors (TETs) commonly infiltrate mediastinal structures, cardiac involvement is uncommon and has not been systematically studied. The purpose of this study was to describe our single-institution experience of the clinical presentation, treatment, and follow-up of cardiac involvement in patients with TETs. METHODS:: A single-institution retrospective review of cardiac involvement among patients with TETs from 2008 to 2012. RESULTS:: The frequency of cardiac involvement was 4%. All five patients with confirmed cardiac disease had left heart involvement. Only one patient was symptomatic. Myocardial invasion was the most common mode of involvement followed by transvenous spread. Surgical resection of the involved area was attempted in three patients: in one, surgery was aborted because of extensive myocardial involvement; in the other two patients, resection was incomplete. Surgery averted a potentially catastrophic hemodynamic complication in one patient. However, cardiac tumor recurred in both patients who underwent incomplete resection. One patient underwent radiation therapy resulting in complete regression of an aortic root mass. CONCLUSIONS:: This study represents the most comprehensive review of cardiac involvement in patients with TETs. In contrast to previous single-case reports, we found a preponderance of asymptomatic presentation, left heart involvement, and myocardial invasion. Dynamic cardiovascular magnetic resonance imaging should be considered in cases when cardiac involvement is suspected. Although immediate surgical resection is indicated for impending hemodynamic compromise, long-term palliation with surgery for myocardial involvement seems poor, especially when complete resection cannot be performed. Radiation therapy should be considered in selected patients.
    Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 02/2013; 8(2):246-249. DOI:10.1097/JTO.0b013e31827bd931 · 4.55 Impact Factor
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    ABSTRACT: 3-Deazaneplanocin A (DZNep) has been shown to have anti-cancer activity in numerous cancer types and its continued preclinical, and eventual clinical, drug development will require rapid and sensitive bioanalytical methods in order to quantitate this drug for pharmacokinetic analyses. The ultra HPLC with positive thermospray tandem mass spectrometric (LC-MS/MS) detection affords the most sensitive (limit of quantitation 5ng/mL) and rapid (3min run time) bioanalytical method to date for DZNep. Due to the polar nature of this drug and the internal standard (tubercidin), a hydrophilic-interaction column (HILIC) was used. The method was accurate, with less than 10% deviation from nominal values, as well as precise, where both within-day and between-day precisions were less than 15%. A liquid-liquid extraction procedure was able to recover ∼90% of drug from a small volume (50μL) of mouse plasma. This method was successfully applied to a pharmacokinetic study in mice intravenously injected with DZNep.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 01/2013; DOI:10.1016/j.jchromb.2013.01.003 · 2.78 Impact Factor
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    ABSTRACT: Epigenetic aberrations offer dynamic and reversible targets for cancer therapy; increasingly, alteration via overexpression, mutation, or rearrangement is found in genes that control the epigenome. Such alterations suggest a fundamental role in carcinogenesis. Here, we consider three epigenetic mechanisms: DNA methylation, histone tail modification and non-coding, microRNA regulation. Evidence for each of these in lung cancer origin or progression has been gathered, along with evidence that epigenetic alterations might be useful in early detection. DNA hypermethylation of tumor suppressor promoters has been observed, along with global hypomethylation and hypoacetylation, suggesting an important role for tumor suppressor gene silencing. These features have been linked as prognostic markers with poor outcome in lung cancer. Several lines of evidence have also suggested a role for miRNA in carcinogenesis and in outcome. Cigarette smoke downregulates miR-487b, which targets both RAS and MYC; RAS is also a target of miR-let-7, again downregulated in lung cancer. Together the evidence implicates epigenetic aberration in lung cancer and suggests that targeting these aberrations should be carefully explored. To date, DNA methyltransferase and histone deacetylase inhibitors have had minimal clinical activity. Explanations include the possibility that the agents are not sufficiently potent to invoke epigenetic reversion to a more normal state; that insufficient time elapses in most clinical trials to observe true epigenetic reversion; and that doses often used may provoke off-target effects such as DNA damage that prevent epigenetic reversion. Combinations of epigenetic therapies may address those problems. When epigenetic agents are used in combination with chemotherapy or targeted therapy it is hoped that downstream biological effects will provoke synergistic cytotoxicity. This review evaluates the challenges of exploiting the epigenome in the treatment of lung cancer.
    Frontiers in Oncology 01/2013; 3:261. DOI:10.3389/fonc.2013.00261
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    ABSTRACT: Cigarette smoke (CS) is a leading cause of death worldwide. The aryl hydrocarbon receptor (AHR) is partially responsible for tobacco-induced carcinogenesis although the underlying mechanisms involving early effector genes have yet to be determined. Here, we report that adrenomedullin (ADM) significantly contributes to the carcinogenicity of tobacco activated AHR. CS and AHR activating ligands induced ADM in vitro and in vivo but not in AHR-deficient fibroblasts and mice. Ectopic transfection of AHR rescued ADM expression in AHR-/- fibroblasts while AHR blockage with siRNA in wild type cells significantly decreased ADM expression. AHR regulates ADM expression through two intronic xenobiotic response elements located close to the start codon in the ADM gene. Using tissue microarrays we showed that ADM and AHR were coupregulated in lung tumor biopsies from smoker patients. Microarray metaanalysis of 304 independent microarray experiments showed that ADM is elevated in smokers and smokers with cancer. Additionally, ADM coassociated with a subset of AHR responsive genes and efficiently differentiated patients with lung cancer from non-smokers. In a novel preclinical model of CS-induced tumor progression, host exposure to CS extracts significantly elevated tumor ADM while systemic treatment with the ADM antagonist NSC16311 efficiently blocked tobacco-induced tumor growth. In conclusion, ADM significantly contributes the carcinogenic effect of AHR and tobacco combustion products. We suggest that therapeutics targeting the AHR/ADM axis may be of clinical relevance in the treatment of tobacco-induced pulmonary malignancies.
    Cancer Research 09/2012; 72(22). DOI:10.1158/0008-5472.CAN-12-0818 · 9.28 Impact Factor
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    ABSTRACT: Cigarette smoking at diagnosis or during therapy correlates with poor outcome in patients with lung and esophageal cancers, yet the underlying mechanisms remain unknown. In this study, we observed that exposure of esophageal cancer cells to cigarette smoke condensate (CSC) led to upregulation of the xenobiotic pump ABCG2, which is expressed in cancer stem cells and confers treatment resistance in lung and esophageal carcinomas. Furthermore, CSC increased the side population of lung cancer cells containing cancer stem cells. Upregulation of ABCG2 coincided with increased occupancy of aryl hydrocarbon receptor, Sp1, and Nrf2 within the ABCG2 promoter, and deletion of xenobiotic response elements and/or Sp1 sites markedly attenuated ABCG2 induction. Under conditions potentially achievable in clinical settings, mithramycin diminished basal as well as CSC-mediated increases in AhR, Sp1, and Nrf2 levels within the ABCG2 promoter, markedly downregulated ABCG2, and inhibited proliferation and tumorigenicity of lung and esophageal cancer cells. Microarray analyses revealed that mithramycin targeted multiple stem cell-related pathways in vitro and in vivo. Collectively, our findings provide a potential mechanistic link between smoking status and outcome of patients with lung and esophageal cancers, and support clinical use of mithramycin for repressing ABCG2 and inhibiting stem cell signaling in thoracic malignancies.
    Cancer Research 07/2012; 72(16):4178-92. DOI:10.1158/0008-5472.CAN-11-3983 · 9.28 Impact Factor
  • Cancer Research 06/2012; 72(8 Supplement):2560-2560. DOI:10.1158/1538-7445.AM2012-2560 · 9.28 Impact Factor
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    ABSTRACT: A review of all resections for recurrent or metastatic ACC was performed to identify patients who might benefit from a surgical approach, and to identify factors that might aid in prognosis among patients with metastatic disease. Adrenocortical carcinoma (ACC) is a rare tumor, with frequent recurrences and metastases even after complete resection. Chemotherapy has limited efficacy, and surgical resection of metastatic ACC remains controversial. A retrospective review was performed of all patients who underwent surgical intervention for metastatic ACC in a single tertiary center from 1977 to 2009. All available clinicopathologic data were analyzed to determine potential factors associated with response to treatment and survival. Fifty-seven patients underwent 116 procedures for recurrent or metastatic disease. Twenty-three resections were for liver metastases, 48 for pulmonary metastases, 22 for abdominal disease including local recurrences, and 13 were for metastases at other sites. Median and 5-year survivals from time of first metastasectomy were 2.5 years, and 41%, respectively. The median survival of patients with DFI <12 months was 1.7 years, compared to 6.6 years for patients with DFI >12 months (P = 0.015). Median survival for right versus left-sided primaries was 1.9 years versus 3.8 years (P = 0.03). Liver metastases were more common with right-sided primaries (67% vs. 41%, P = 0.05). Chemotherapy had no impact on survival. Resection of recurrent or metastatic ACC is safe, and may result in prolongation of survival in selected patients with DFI greater than 1 year.
    Journal of Surgical Oncology 06/2012; 105(7):709-13. DOI:10.1002/jso.23015 · 2.84 Impact Factor
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    ABSTRACT: CD4(+)FoxP3(+) regulatory T cells (Tregs) have been shown to suppress T cell-mediated host immune responses against self- and nonself-antigens; however, the impact of CD4(+) Tregs on human antitumor immune responses and their influence on cancer treatment are unknown. In the present study, we explored the factors that influence CD4(+) Treg reconstitution in patients receiving adoptive immunotherapy following conditioning regimens designed to enhance T-cell function and evaluated potential associations between CD4(+) Treg levels and clinical responses to therapy. The analysis of 4 trials employing nonmyeloablative chemotherapy with or without total body irradiation (TBI) before adoptive T-cell transfer revealed that the percentage and number of reconstituting CD4(+)FoxP3(+) Tregs observed in the peripheral blood was higher in nonresponders than in responders. The addition of TBI resulted in a further depletion of CD4(+) Tregs, and the degree of depletion was dependent on the TBI dose. The number of administered doses of IL-2 was found to be positively associated with peripheral Treg reconstitution. These observations provide strong evidence that endogenous CD4(+) Tregs have a negative impact on cancer therapy, and suggest that strategies reducing Treg levels may provide clinical benefit to cancer patients. All 5 clinical trials are registered at www.clinicaltrials.gov as NCT00001832, NCT00096382, NCT00335127, NCT00509496, and NCT00513604.
    Blood 05/2012; 119(24):5688-96. DOI:10.1182/blood-2011-10-386482 · 9.78 Impact Factor
  • David S Schrump
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    ABSTRACT: Lung and esophageal cancers and malignant pleural mesotheliomas are highly lethal neoplasms that are leading causes of cancer-related deaths worldwide. Presently, limited information is available pertaining to epigenetic mechanisms mediating initiation and progression of these neoplasms. The following presentation will focus on the potential clinical relevance of epigenomic alterations in thoracic malignancies mediated by DNA methylation, perturbations in the histone code, and polycomb group proteins, as well as ongoing translational efforts to target epigenetic regulators of gene expression for treatment of these neoplasms. This article is part of a Special Issue entitled: Chromatin in time and space.
    Biochimica et Biophysica Acta 04/2012; 1819(7):836-45. DOI:10.1016/j.bbagrm.2012.03.009 · 4.66 Impact Factor

Publication Stats

4k Citations
706.60 Total Impact Points


  • 1999–2015
    • National Cancer Institute (USA)
      • • Center for Cancer Research
      • • Surgery Branch
      베서스다, Maryland, United States
  • 2005–2014
    • NCI-Frederick
      Maryland, United States
    • Howard Hughes Medical Institute
      Ashburn, Virginia, United States
  • 1999–2012
    • National Institutes of Health
      • • Branch of Surgery
      • • Center for Clinical Research
      Maryland, United States
  • 1998–2007
    • Northern Inyo Hospital
      BIH, California, United States
  • 2003
    • The National Institute of Diabetes and Digestive and Kidney Diseases
      베서스다, Maryland, United States
  • 1996–2000
    • University of Texas MD Anderson Cancer Center
      • Department of Thoracic Cardiovascular Surgery
      Houston, Texas, United States
  • 1997
    • University of Houston
      Houston, Texas, United States