Immune checkpoint inhibitors (ICI) have improved the prognosis of non-small-cell lung cancer (NSCLC) but can also cause immune-related adverse events (irAEs), which can be life-threatening and have a complex management. Currently, there is a need for molecular and clinical markers to predict irAEs occurrence and outcome. Clinical characteristics of 762 patients with stage IV NSCLC receiving first- or second-line PD-(L)1 inhibitors were analyzed. Additionally, blood samples of 8 patients with irAEs were analyzed at baseline (BL) and at the time of toxicity (TT) in comparison with 8 matched control samples from patients with similar clinical characteristics and ICI exposure, but no irAEs. The expression of 12 genes involved in the immune response (GATA3, TBX21, MKI67, CD247, FAS, FASLv1, FOXP3, GzmB, IFNγ, PD1, PRF1, RORgt) was absolutely quantified in PAXgene blood RNA samples using RT-PCR and plasmid standards. IrAEs occurred in 176/762 cases (23%), with a similar frequency for ICI monotherapy or chemoimmunotherapy (24% vs. 22%). CTCAE severity was grade 1 in 11%, grade 2 in 41%, grade 3 in 37%, grade 4 in 10%, and 2 events were lethal (1%). Frequently affected were endocrine glands (21%), lungs (17%), musculoskeletal system (17%), colon (15%) and liver (15%). All other organs were less commonly affected (15%). IrAEs occurrence showed a significant association with a better ECOG performance status (28% vs. 18% for PS 0 vs. 1, p = 0.006), PD-L1 positivity (25% vs. 14%, p = 0.009), and a lower neutrophil-to-lymphocyte ratio (NLR, 28% vs. 19% with the median 6.2 as cut-off, p = 0.004). Blood cell gene expressions in patients with irAEs was slightly higher for 7/12 immunologically relevant genes at TT, and for 11/12 genes at BL, but not significantly different (p≥0.07). No substantial changes in gene expression were noted between BL and TT in each group (mean fold change for the irAEs group = 0.82, for the controls = 0.84, p ≥0.07). IrAEs under PD-(L)1 inhibitors occur more frequently in patients with PD-L1-positive NSCLC, a better ECOG PS, and a lower NLR. No relationship between the blood expression of selected immunologically relevant genes and irAEs occurrence was noted.

BackgroundMetastatic non-small-cell lung cancers (NSCLC) with PD-L1 tumor proportion score (TPS) ≥ 50% are immune reactive neoplasms with sensitivity to first-line pembrolizumab monotherapy. However, reliable biomarkers to identify patients who benefit from this line of treatment are still lacking.MethodsWe retrospectively analyzed baseline blood samples of newly diagnosed stage IV NSCLC patients with PD-L1 TPS ≥50% who received pembrolizumab monotherapy and experienced rapid progression (RP, progression-free survival [PFS] <3 months, n=17), or a durable benefit under treatment (DB, [PFS] >6 months, n=27). The expression for 13 genes (PD1, FOXP3, CD247, PRF1, GZMB, TBX21, MKI67, HLA-DRA, FAS, FASLG, GATA3, RORγt, IFNγ) of special immunologic interest was quantified in absolute terms using real-time PCR from reverse-transcribed whole blood RNA.ResultsPatients in the DB group had a significantly higher percentage of lymphocytes (Ly%, 15.7% vs 11.8%; p= 0.004), a lower neutrophil-to-lymphocyte ratio (NLR, 5.0 vs. 7.8, p=0.011), a higher absolute lymphocyte count (ALC, 1.49 vs 1.22 x103/μl; p =0.043) and a higher overall expression of PD1 (2,204 vs. 1,671 x103 copies/μg blood RNA, p=0.016) in peripheral blood compared to the RP group. Adjustment for the Ly% of each sample revealed that patients in the RP had a higher relative expression of FOXP3 and TBX21 compared to these in the DB group (6,150 vs. 3,531 x103 copies/μg RNA, p= 0.003; and 80,776 vs. 61,361 x103 copies/μg RNA, p= 0.023, respectively).ConclusionsDurable clinical response to pembrolizumab monotherapy in NSCLC is associated with higher absolute counts and percentages of lymphocytes, a higher expression of PD-1, and a relative downregulation of FOXP3 and TBX21 in the peripheral blood prior to therapy start. Ongoing work aims to validate these findings in larger patient cohorts, evaluate longitudinal changes under treatment, and analyze the potential clinical utility in other NSCLC patient subsets.Legal entity responsible for the studyThoraxklinik Heidelberg.FundingGerman Center for Lung Research (DZL).DisclosureM. Thomas: Financial Interests, Institutional, Funding: AstraZeneca; Financial Interests, Institutional, Funding: Bristol Myers Squibb; Financial Interests, Institutional, Funding: Roche; Financial Interests, Institutional, Funding: Takeda; Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Advisory Board: Bristol Myers Squibb; Financial Interests, Personal, Advisory Board: Boehringer Ingelheim; Financial Interests, Personal, Advisory Board: Celgene; Financial Interests, Personal, Advisory Board: Chugai; Financial Interests, Personal, Advisory Board: Lilly; Financial Interests, Personal, Advisory Board: MSD; Financial Interests, Personal, Advisory Board: Novartis; Financial Interests, Personal, Advisory Board: Pfizer; Financial Interests, Personal, Advisory Board: Roche; Financial Interests, Personal, Advisory Board: Takeda; Financial Interests, Personal, Advisory Board: Sanofi; Financial Interests, Personal, Advisory Board: Beigene; Financial Interests, Personal, Advisory Board: GlaxoSmithKline. P. Christopoulos: Financial Interests, Institutional, Funding: AstraZeneca; Financial Interests, Institutional, Funding: Novartis; Financial Interests, Institutional, Funding: Roche; Financial Interests, Institutional, Funding: Takeda; Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Advisory Board: Boehringer Ingelheim; Financial Interests, Personal, Advisory Board: Chugai; Financial Interests, Personal, Advisory Board: Kite; Financial Interests, Personal, Advisory Board: Novartis; Financial Interests, Personal, Advisory Board: Pfizer; Financial Interests, Personal, Advisory Board: Roche; Financial Interests, Personal, Advisory Board: Takeda. All other authors have declared no conflicts of interest. BackgroundMetastatic non-small-cell lung cancers (NSCLC) with PD-L1 tumor proportion score (TPS) ≥ 50% are immune reactive neoplasms with sensitivity to first-line pembrolizumab monotherapy. However, reliable biomarkers to identify patients who benefit from this line of treatment are still lacking. Metastatic non-small-cell lung cancers (NSCLC) with PD-L1 tumor proportion score (TPS) ≥ 50% are immune reactive neoplasms with sensitivity to first-line pembrolizumab monotherapy. However, reliable biomarkers to identify patients who benefit from this line of treatment are still lacking. MethodsWe retrospectively analyzed baseline blood samples of newly diagnosed stage IV NSCLC patients with PD-L1 TPS ≥50% who received pembrolizumab monotherapy and experienced rapid progression (RP, progression-free survival [PFS] <3 months, n=17), or a durable benefit under treatment (DB, [PFS] >6 months, n=27). The expression for 13 genes (PD1, FOXP3, CD247, PRF1, GZMB, TBX21, MKI67, HLA-DRA, FAS, FASLG, GATA3, RORγt, IFNγ) of special immunologic interest was quantified in absolute terms using real-time PCR from reverse-transcribed whole blood RNA. We retrospectively analyzed baseline blood samples of newly diagnosed stage IV NSCLC patients with PD-L1 TPS ≥50% who received pembrolizumab monotherapy and experienced rapid progression (RP, progression-free survival [PFS] <3 months, n=17), or a durable benefit under treatment (DB, [PFS] >6 months, n=27). The expression for 13 genes (PD1, FOXP3, CD247, PRF1, GZMB, TBX21, MKI67, HLA-DRA, FAS, FASLG, GATA3, RORγt, IFNγ) of special immunologic interest was quantified in absolute terms using real-time PCR from reverse-transcribed whole blood RNA. ResultsPatients in the DB group had a significantly higher percentage of lymphocytes (Ly%, 15.7% vs 11.8%; p= 0.004), a lower neutrophil-to-lymphocyte ratio (NLR, 5.0 vs. 7.8, p=0.011), a higher absolute lymphocyte count (ALC, 1.49 vs 1.22 x103/μl; p =0.043) and a higher overall expression of PD1 (2,204 vs. 1,671 x103 copies/μg blood RNA, p=0.016) in peripheral blood compared to the RP group. Adjustment for the Ly% of each sample revealed that patients in the RP had a higher relative expression of FOXP3 and TBX21 compared to these in the DB group (6,150 vs. 3,531 x103 copies/μg RNA, p= 0.003; and 80,776 vs. 61,361 x103 copies/μg RNA, p= 0.023, respectively). Patients in the DB group had a significantly higher percentage of lymphocytes (Ly%, 15.7% vs 11.8%; p= 0.004), a lower neutrophil-to-lymphocyte ratio (NLR, 5.0 vs. 7.8, p=0.011), a higher absolute lymphocyte count (ALC, 1.49 vs 1.22 x103/μl; p =0.043) and a higher overall expression of PD1 (2,204 vs. 1,671 x103 copies/μg blood RNA, p=0.016) in peripheral blood compared to the RP group. Adjustment for the Ly% of each sample revealed that patients in the RP had a higher relative expression of FOXP3 and TBX21 compared to these in the DB group (6,150 vs. 3,531 x103 copies/μg RNA, p= 0.003; and 80,776 vs. 61,361 x103 copies/μg RNA, p= 0.023, respectively). ConclusionsDurable clinical response to pembrolizumab monotherapy in NSCLC is associated with higher absolute counts and percentages of lymphocytes, a higher expression of PD-1, and a relative downregulation of FOXP3 and TBX21 in the peripheral blood prior to therapy start. Ongoing work aims to validate these findings in larger patient cohorts, evaluate longitudinal changes under treatment, and analyze the potential clinical utility in other NSCLC patient subsets. Durable clinical response to pembrolizumab monotherapy in NSCLC is associated with higher absolute counts and percentages of lymphocytes, a higher expression of PD-1, and a relative downregulation of FOXP3 and TBX21 in the peripheral blood prior to therapy start. Ongoing work aims to validate these findings in larger patient cohorts, evaluate longitudinal changes under treatment, and analyze the potential clinical utility in other NSCLC patient subsets.

CT scans are the gold standard to measure treatment success of Non-Small Cell Lung Cancer (NSCLC) therapies. In recent years, liquid biopsies became an adequate diagnostic tool especially in advanced disease stages. Here, we investigated very early tumor response of patients receiving chemotherapy or targeted therapies using a panel of already established and explorative liquid biomarkers. Blood samples from patients were taken at baseline and day + 1 for the chemotherapy cohort (n = 25) and at baseline, day +7 and +14 for the targeted therapy cohort (n = 25). DNA mutational load, a panel of 17 microRNAs, glycodelin, glutathione disulfide, glutathione, soluble caspase-cleaved keratin 18 (M30 antigen) and soluble keratin 18 (M65 antigen) were measured using serum and plasma from patients. Baseline and first follow-up CT scan were evaluated by an experienced radiologist and correlated with biomarker data. In the majority of patients a decrease in glycodelin abundance as well as mutational load coincided with clinical response as assessed by CT scan. Consequently, an increase of these biomarkers implicated progressive disease. Among the measured miRNAs, miR-103, miR-628-3p, and let-7e showed largely similar behavior within individual patients upon treatment initiation. The abundance of these miRNAs increased in responding patients and in a subset of patients experiencing tumor progression. Similar observations were seen for the apoptosis markers while the best results were obtained with the detection of M65. Taken together, several investigated biomarkers showed high potential for an early response capturing in defined NSCLC cohorts.

Background: Currently, there is no possibility to detect early tumor response in lung cancer patients within the first days after chemotherapy (CTx) or tyrosine kinase inhibitor (TKI) therapy induction. Using the current gold standard for therapy monitoring, i.e. the measurement of morphologic differences according to RECIST 1.1 by CT and MRI, changes are detected only after weeks or months. Thus, patients may undergo eventually ineffective treatment and suffer from unnecessary toxicity, with both causing relevant costs. This highlights the importance of early response detection to guide and optimize therapy. Monitoring treatment response with diffusion-weighted and dynamic contrast perfusion MR imaging has been proposed for some time as a new powerful tool that will allow determining tumor response much earlier than RECIST. Trial design: This is an observational, prospective, multicenter, non-randomized, open clinical study. 150 patients with non-squamous NSCLC undergoing systemic treatment receive MRI before and after 1st-line therapy. The first follow-up (FU) MRI for patients undergoing chemotherapy is performed 24 hours post treatment. Patients treated with TKIs undergo MRI at days 7 and 14 after therapy induction. A thoracic MRI protocol is performed, including navigated diffusion-weighted imaging with the acquisition of 6 b-values, while the evaluation will focus on the non-perfusion sensitive b-values 400 and 800 (online calculated trace images) and the apparent diffusion coefficient (ADC). Software-based analysis of user-defined ROIs is used to assess the ADC value inside the tumor. ROIs are put in the solid part of the tumorous lesion. So far, 54 patients (28 TKI, 26 CTx) have been included. Findings will be correlated with routinely performed FU CT-imaging and the clinical outcome during FU visits. Further, an accompanying biomarker program aims to elucidate ultra-early blood-bound signs of apoptosis in correlation with MRI signals. This multicenter study will address the unmet clinical need of ultra-early detection of therapy response in NSCLC in order to translate this promising approach into broad clinical practice. Legal entity responsible for the study: Claus Peter Heussel. Funding: German Center for Lung Research (DZL). Disclosure: H-U. Kauczor: Grant: Siemens; Speakers bureau: Boehringer Ingelheim, Philips; Grant, speakers' bureau: Bracco, Bayer. M. Thomas: Speaker: Lilly, BMS, MSD, Roche, Pfizer, AstraZeneca; Advisory board: Lilly, BMS, MSD, Roche, Pfizer, AstraZeneca, Cellgene, Mediolanum. H. Golpon: Advisory boards: Roche, AstraZeneca, Boehringer Ingelheim, BMS. A. Tufman: Advisory boards: Roche, AstraZeneca, Boehringer Ingelheim. C.P. Heussel: Consultation or other fees: Schering-Plough, Pfizer, Basilea, Boehringer Ingelheim, Novartis, Roche, Astellas, Gilead, MSD, Lilly, Intermune, Fresenius; Research funding: Siemens, Pfizer, MeVis, Boehringer Ingelheim; Lecture fees: Gilead, Essex, Schering-Plough, AstraZeneca, Lilly, Roche, MSD, Pfizer , Bracco, Meda Pharma, Intermune, Chiesi, Siemens, Covidien, Pierre Fabre, Boehringer Ingelheim, Grifols, Novartis, Basilea, Bayer. F. Bozorgmehr: Research funding: BMS; Honoraria: MSD, Novartis. All other authors have declared no conflicts of interest.

Defects in DNA repair genes are increasingly recognized as a defining molecular feature of a subset of patients with prostate cancer [1.Pritchard C.C. Mateo J. Walsh M.F. et al.Inherited DNA-repair gene mutations in men with metastatic prostate cancer.N Engl J Med. 2016; 375: 443-453Crossref PubMed Scopus (937) Google Scholar]. Poly (ADP-ribose) polymerase (PARP) inhibitors have been shown to have clinical activity in this subgroup [2.Mateo J. Carreira S. Sandhu S. et al.DNA-repair defects and olaparib in metastatic prostate cancer.N Engl J Med. 2015; 373: 1697-1708Crossref PubMed Scopus (1504) Google Scholar]), but other compounds including platinum also warrant exploration [3.Hager S. Ackermann C.J. Joerger M. et al.Anti-tumour activity of platinum compounds in advanced prostate cancer—a systematic literature review.Ann Oncol. 2016; 27: 975-984Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar, 4.Cheng H.H. Pritchard C.C. Boyd T. et al.Biallelic inactivation of BRCA2 in platinum-sensitive metastatic castration-resistant prostate cancer.Eur Urol. 2016; 69: 992-995Abstract Full Text Full Text PDF PubMed Scopus (206) Google Scholar]. We report here the remarkable clinical course of a patient with a germline BRCA2 mutation treated with the PARP inhibitor olaparib. The patient was diagnosed in June 2013 at the age of 60 years with primary metastatic prostate cancer and skeletal involvement. Because of the family history, genetic testing was recommended. A deleterious germline BRCA2 mutation was detected that was later confirmed in the primary tumor by targeted next-generation sequencing. After neoadjuvant hormonal therapy, the patient underwent a radical prostatectomy in line with emerging evidence [5.Culp S.H. Schellhammer P.F. Williams MB. Might men diagnosed with metastatic prostate cancer benefit from definitive treatment of the primary tumor? A SEER-based study.Eur Urol. 2014; 65: 1058-1066Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar] and received radiotherapy of the pelvic bone. Androgen deprivation therapy was continued, and the patient rapidly developed castration resistance after 4 months (Figure 1A). The therapy was switched to abiraterone and resulted in transient disease control for 10 months. The patient was subsequently treated with enzalutamide and the prostate-specific antigen (PSA) value increased again after 6 months. A positron emission tomography/computed tomography (CT) with a 68Ga-prostate-specific membrane antigen (PSMA) ligand in July 2015 showed tracer uptake in a mediastinal lymph node and progression of the bone metastases. Therapy was changed to docetaxel (75 mg/m2) followed by a significant PSA increase from 162 to 504 ng/ml after six cycles. The patient reported increasing bone pain in the sternum, right iliac crest, and right shoulder with a palpable swelling in the area of the distal clavicle of about 30 mm thickness. Based on the TOPARP-A study [2.Mateo J. Carreira S. Sandhu S. et al.DNA-repair defects and olaparib in metastatic prostate cancer.N Engl J Med. 2015; 373: 1697-1708Crossref PubMed Scopus (1504) Google Scholar] results, the therapy was changed to olaparib monotherapy in January 2016. The patient rapidly became pain-free, discontinued analgetics, and resumed full-time professional activities. The palpable swelling in the right clavicular area had completely resolved clinically, and after 12 weeks on olaparib, the PSA value had declined from 504 to 49 ng/ml. However, CT scans taken in April 2016 showed a massive progression of sclerotic skeletal metastases during the olaparib treatment (Figure 1B and C). The patient reported worsening of conditions with bone pain, night sweats, and general fatigue. A second positron emission tomography/CT scan with the 68Ga-PSMA ligand in June 2016 confirmed the sclerotic bone lesions to represent rapidly progressive skeletal metastases (Figure 1D). Remarkably, a mediastinal lymph node metastasis with high tracer uptake in July 2015 showed no accumulation of the PSMA ligand after 20 weeks of olaparib (Figure 1E and F). To reconcile the rapid development of resistance to the PARP inhibitor in the bone, we performed next-generation sequencing of a panel of 49 genes (ACPv2; Ion Torrent Technology) using DNA isolated from the primary tumor. A pathogenic somatic mutation in the pleckstrin homology domain of the AKT1 gene (E17K; allele frequency 25.6%) was discovered that leads to a constitutive activation of the AKT1 protein kinase. Activated AKT has previously been reported to impair the effectiveness of PARP inhibition, and AKT inhibition can be safely combined with olaparib to induce tumor responses [6.Michalarea V. Roda D. Drew Y. et al.Phase I trial combining the PARP inhibitor olaparib (Ola) and AKT inhibitor AZD5363 (AZD) in germline (g)BRCA and non-BRCA mutant (m) advanced cancer patients (pts) incorporating noninvasive monitoring of cancer mutations.Cancer Res. 2016; 76: CT010-CT011Google Scholar]. Our findings urge for careful attention to heterogeneous oncological responses and the development of acquired resistance in men with advanced prostate cancer and mutations in DNA repair genes treated with olaparib. While mechanisms of resistance to PARP inhibition such as AKT1 mutations are beginning to emerge, increasing the effectiveness of PARP inhibitors as well as combination therapies should be considered. The Medical Faculty Heidelberg of the University of Heidelberg Medical School (no grant number).

Analysis of spatially distinct regions revealed a considerable histological and molecular heterogeneity of lung adenocarcinomas (ADCs). The predominant histological growth pattern and driver gene alterations (e.g. in EGFR and KRAS) have been shown to be of high prognostic and therapeutic relevance. This project aimed to examine the spatial distributions of EGFR and KRAS mutation frequencies in the various histological growth patterns of ADCs. Central tumor sections from 19 ADCs were subdivided into 467 tumor segments of 5x5 mm. The segments were evaluated separately in order to enable a systematic analysis of histological and molecular markers within and between patients. We determined the predominant histological growth patterns and the variant allele frequencies (VAFs) of EGFR and KRAS in each segment by digital PCR. We further quantified the absolute cell counts and proportions of tumor and non-neoplastic cells in all segments in order to examine the cellular fractions and allow a precise normalization of VAFs. Histopathological classification revealed morphological intratumor heterogeneity with more than one histological growth pattern in 16 of the 19 cases. The 467 malignant segments exhibited a mean tumor cell fraction of 28% with an extensive variability within and between the individual cases. The predominant solid pattern revealed the significantly lowest fraction of tumor cells. Furthermore, EGFR and KRAS VAFs were measured by digital PCR and normalized to the cellular fractions of the respective segment. While driver gene mutations were detected in >99% of malignant segments, we found a heterogeneous spatial distribution of normalized VAFs: Some cases showed ubiquitously low or high mutant allele frequencies, others revealed regions with focally elevated frequencies and driver gene amplifications. In addition, we found a significant correlation between mutated allele frequencies and histological patterns. Micropapillary and solid patterns harbored higher mutant allele frequencies compared to lepidic and papillary histologies. Correlation analysis did not show an association between the tumor size and the normalized VAF or driver gene amplification. Our findings indicate that driver gene mutations are present with high levels of inter- and intratumor heterogeneity throughout all ADC samples tested. Allele frequencies correlated with histological growth patterns, but not with tumor size.

Circulating cell-free DNA (cfDNA) released from cancerous tissues has been found to harbor tumor-associated alterations and to represent the molecular composition of the tumor. Recent advances in technologies, especially in next-generation sequencing, enable the analysis of low amounts of cfDNA from body fluids. We analyzed the exomes of tumor tissue and matched serum samples to investigate the molecular representation of the tumor exome in cfDNA. To this end, we implemented a workflow for sequencing of cfDNA from low serum volumes (200 μl) and performed whole-exome sequencing (WES) of serum and matched tumor tissue samples from six non-small cell lung cancer (NSCLC) patients and two control sera. Exomes, including untranslated regions (UTRs) of cfDNA were sequenced with an average coverage of 68.5x. Enrichment efficiency, target coverage, and sequencing depth of cfDNA reads were comparable to those from matched tissues. Discovered variants were compared between serum and tissue as well as to the COSMIC database of known mutations. Although not all tissue variants could be confirmed in the matched serum, up to 57% of the tumor variants were reflected in matched cfDNA with mutations in PIK3CA, ALK, and PTEN as well as variants at COSMIC annotated sites in all six patients analyzed. Moreover, cfDNA revealed a mutation in MTOR, which was not detected in the matched tissue, potentially from an untested region of the heterogeneous primary tumor or from a distant metastatic clone. WES of cfDNA may provide additional complementary molecular information about clinically relevant mutations and the clonal heterogeneity of the tumors.

Journal of Viral HepatitisVolume 22, Issue S2 p. 33-33 Poster PresentationFree Access P028: Comparative microarray analysis of susceptible hepatoma cell lines upon infection with Hepatitis B (HBV) and Hepatitis delta virus (HDV) First published: 25 June 2015 https://doi.org/10.1111/jvh.26_12425AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume22, IssueS2Special Issue: 15th International Symposium on Viral Hepatitis and Liver Diseases (ISVHLD) held from June 26th to 28th, 2015, in Berlin, GermanyJune 2015Pages 33-33 RelatedInformation

The epigenetic sensor BRD4 (bromodomain protein 4) is a potent target for anti-cancer therapies. To study the transcriptional impact of BRD4 in cancer, we generated an expression signature of BRD4 knockdown cells and found oxidative stress response genes significantly enriched. We integrated the RNA-Seq results with DNA-binding sites of BRD4 generated by chromatin immunoprecipitations, correlated these with gene expressions from human prostate cancers and identified 21 top BRD4 candidate genes among which the oxidative stress pathway genes KEAP1, SESN3 and HDAC6 are represented. Knock down of BRD4 or treatment with the BRD4 inhibitor JQ1 resulted in decreased reactive oxygen species (ROS) production and increased cell viability under H2O2 exposure. Consistently, a deregulation of BRD4 diminished the KEAP1/NRF2 axis and led to a disturbed regulation of the inducible heme oxygenase 1 (HMOX1). Without exogenous stress induction, we also found BRD4 directly targeting the HMOX1 promoter over the SP1-binding sites. Our findings provide insight into the transcriptional regulatory network of BRD4 and highlight BRD4 as signal transducer of the cellular response to oxidative stress.

of cellular growth both 'in vitro' and 'in vivo' models of cancer.Furthermore, GRK2 levels are increased in a very significant proportion of infiltrating ductal carcinoma samples from patients, strongly suggesting that GRK2 is a relevant modulator of tumor survival and progression 331