Hamdan, Feda Hisham Mohd

[["dc.bibliographiccitation.firstpage","394"],["dc.bibliographiccitation.journal","EBioMedicine"],["dc.bibliographiccitation.lastpage","405"],["dc.bibliographiccitation.volume","40"],["dc.contributor.author","Patzak, Melanie S."],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Patil, Shilpa"],["dc.contributor.author","Hamdan, Feda H."],["dc.contributor.author","Goetze, Robert G."],["dc.contributor.author","Brunner, Marius"],["dc.contributor.author","Gaedcke, Jochen"],["dc.contributor.author","Kitz, Julia"],["dc.contributor.author","Jodrell, Duncan I."],["dc.contributor.author","Richards, Frances M."],["dc.contributor.author","Pilarsky, Christian"],["dc.contributor.author","Gruetzmann, Robert"],["dc.contributor.author","Rümmele, Petra"],["dc.contributor.author","Knösel, Thomas"],["dc.contributor.author","Hessmann, Elisabeth"],["dc.contributor.author","Ellenrieder, Volker"],["dc.contributor.author","Johnsen, Steven A."],["dc.contributor.author","Neesse, Albrecht"],["dc.date.accessioned","2019-07-09T11:50:10Z"],["dc.date.available","2019-07-09T11:50:10Z"],["dc.date.issued","2019"],["dc.description.abstract","BACKGROUND: Cytosolic 5'-nucleotidase 1A (NT5C1A) dephosphorylates non-cyclic nucleoside monophosphates to produce nucleosides and inorganic phosphates. Here, we investigate NT5C1A expression in pancreatic ductal adenocarcinoma (PDAC) and its impact on gemcitabine metabolism and therapeutic efficacy. METHODS: NT5C1A expression was determined by semiquantitative immunohistochemistry using tissue microarrays. Gemcitabine metabolites and response were assessed in several human and murine PDAC cell lines using crystal violet assays, Western blot, viability assays, and liquid chromatography tandem mass-spectrometry (LC-MS/MS). FINDINGS: NT5C1A was strongly expressed in tumor cells of a large subgroup of resected PDAC patients in two independent patient cohorts (44-56% score 2 and 8-26% score 3, n = 414). In contrast, NT5C1A was expressed at very low levels in the tumor stroma, and neither stromal nor tumoral expression was a prognostic marker for postoperative survival. In vitro, NT5C1A overexpression increased gemcitabine resistance by reducing apoptosis levels and significantly decreased intracellular amounts of cytotoxic dFdCTP in +NT5C1A tumor cells. Co-culture experiments with conditioned media from +NT5C1A PSCs improved gemcitabine efficacy in tumor cells. In vivo, therapeutic efficacy of gemcitabine was significantly decreased and serum levels of the inactive gemcitabine metabolite dFdU significantly increased in mice bearing NT5C1A overexpressing tumors. INTERPRETATION: NT5C1A is robustly expressed in tumor cells of resected PDAC patients. Moreover, NT5C1A mediates gemcitabine resistance by decreasing the amount of intracellular dFdCTP, leading to reduced tumor cell apoptosis and larger pancreatic tumors in mice. Further studies should clarify the role of NT5C1A as novel predictor for gemcitabine treatment response in patients with PDAC."],["dc.identifier.doi","10.1016/j.ebiom.2019.01.037"],["dc.identifier.pmid","30709769"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15875"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59716"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","2352-3964"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-nd/4.0"],["dc.subject.ddc","610"],["dc.title","Cytosolic 5'-nucleotidase 1A is overexpressed in pancreatic cancer and mediates gemcitabine resistance by reducing intracellular gemcitabine metabolites."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3130"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Nucleic Acids Research"],["dc.bibliographiccitation.lastpage","3145"],["dc.bibliographiccitation.volume","45"],["dc.contributor.author","Nagarajan, Sankari"],["dc.contributor.author","Bedi, Upasana"],["dc.contributor.author","Budida, Anusha"],["dc.contributor.author","Hamdan, Feda H."],["dc.contributor.author","Mishra, Vivek Kumar"],["dc.contributor.author","Najafova, Zeynab"],["dc.contributor.author","Xie, Wanhua"],["dc.contributor.author","Alawi, Malik"],["dc.contributor.author","Indenbirken, Daniela"],["dc.contributor.author","Knapp, Stefan"],["dc.contributor.author","Chiang, Cheng-Ming"],["dc.contributor.author","Grundhoff, Adam"],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Scheel, Christina H."],["dc.contributor.author","Wegwitz, Florian"],["dc.contributor.author","Johnsen, Steven A."],["dc.date.accessioned","2018-11-07T10:25:04Z"],["dc.date.available","2018-11-07T10:25:04Z"],["dc.date.issued","2017"],["dc.description.abstract","Bromodomain-containing protein 4 (BRD4) is a member of the bromo-and extraterminal (BET) domain-containing family of epigenetic readers which is under intensive investigation as a target for anti-tumor therapy. BRD4 plays a central role in promoting the expression of select subsets of genes including many driven by oncogenic transcription factors and signaling pathways. However, the role of BRD4 and the effects of BET inhibitors in non-transformed cells remain mostly unclear. We demonstrate that BRD4 is required for the maintenance of a basal epithelial phenotype by regulating the expression of epithelial-specific genes including TP63 and Grainy Head-like transcription factor-3 (GRHL3) in non-transformed basal-like mammary epithelial cells. Moreover, BRD4 occupancy correlates with enhancer activity and enhancer RNA (eRNA) transcription. Motif analyses of cell context-specific BRD4-enriched regions predicted the involvement of FOXOtranscription factors. Consistently, activation of FOXO1 function via inhibition of EGFR-AKT signaling promoted the expression of TP63 and GRHL3. Moreover, activation of Src kinase signaling and FOXO1 inhibition decreased the expression of FOXO/BRD4 target genes. Together, our findings support a function for BRD4 in promoting basal mammary cell epithelial differentiation, at least in part, by regulating FOXO factor function on enhancers to activate TP63 and GRHL3 expression."],["dc.identifier.doi","10.1093/nar/gkw1276"],["dc.identifier.isi","000398376200026"],["dc.identifier.pmid","27980063"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14764"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42778"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1362-4962"],["dc.relation.issn","0305-1048"],["dc.rights","CC BY-NC 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc/4.0"],["dc.title","BRD4 promotes p63 and GRHL3 expression downstream of FOXO in mammary epithelial cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","98"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Clinical Epigenetics"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Schneider, Deborah"],["dc.contributor.author","Chua, Robert L"],["dc.contributor.author","Molitor, Nicole"],["dc.contributor.author","Hamdan, Feda H"],["dc.contributor.author","Rettenmeier, Eva M"],["dc.contributor.author","Prokakis, Evangelos"],["dc.contributor.author","Mishra, Vivek K"],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Wegwitz, Florian"],["dc.contributor.author","Johnsen, Steven A"],["dc.contributor.author","Kosinsky, Robyn L"],["dc.date.accessioned","2019-07-09T11:51:58Z"],["dc.date.available","2019-07-09T11:51:58Z"],["dc.date.issued","2019"],["dc.description.abstract","Abstract Background Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide, and deciphering underlying molecular mechanism is essential. The loss of monoubiquitinated histone H2B (H2Bub1) was correlated with poor prognosis of CRC patients and, accordingly, H2Bub1 was suggested as a tumor-suppressive mark. Surprisingly, our previous work revealed that the H2B ubiquitin ligase RING finger protein 40 (RNF40) might exert tumor-promoting functions. Here, we investigated the effect of RNF40 loss on tumorigenic features of CRC cells and their survival in vitro. Methods We evaluated the effects of RNF40 depletion in several human CRC cell lines in vitro. To evaluate cell cycle progression, cells were stained with propidium iodide and analyzed by flow cytometry. In addition, to assess apoptosis rates, caspase 3/7 activity was assessed in a Celigo® S-based measurement and, additionally, an Annexin V assay was performed. Genomic occupancy of H2Bub1, H3K79me3, and H3K27ac was determined by chromatin immunoprecipitation. Transcriptome-wide effects of RNF40 loss were evaluated based on mRNA-seq results, qRT-PCR, and Western blot. To rescue apoptosis-related effects, cells were treated with Z-VAD-FMK. Results Human CRC cell lines displayed decreased cell numbers in vitro after RNF40 depletion. While the differences in confluence were not mediated by changes in cell cycle progression, we discovered highly increased apoptosis rates after RNF40 knockdown due to elevated caspase 3/7 activity. This effect can be explained by reduced mRNA levels of anti-apoptotic and upregulation of pro-apoptotic BCL2 family members. Moreover, the direct occupancy of the RNF40-mediated H2B monoubiquitination was observed in the transcribed region of anti-apoptotic genes. Caspase inhibition by Z-VAD-FMK treatment rescued apoptosis in RNF40-depleted cells. However, knockdown cells still displayed decreased tumorigenic features despite the absence of apoptosis. Conclusions Our findings reveal that RNF40 is essential for maintaining tumorigenic features of CRC cells in vitro by controlling the expression of genes encoding central apoptotic regulators."],["dc.identifier.doi","10.1186/s13148-019-0698-x"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16251"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60054"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","BioMed Central"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","The E3 ubiquitin ligase RNF40 suppresses apoptosis in colorectal cancer cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","1142"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Cancers"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Flebbe, Hannah"],["dc.contributor.author","Hamdan, Feda H."],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Kitz, Julia"],["dc.contributor.author","Gaedcke, Jochen"],["dc.contributor.author","Ghadimi, B. Michael"],["dc.contributor.author","Johnsen, Steven A."],["dc.contributor.author","Grade, Marian"],["dc.date.accessioned","2019-08-14T10:46:50Z"],["dc.date.available","2019-08-14T10:46:50Z"],["dc.date.issued","2019"],["dc.description.abstract","Epigenetic alterations play a central role in cancer development and progression. The acetylation of histone 3 at lysine 27 (H3K27ac) specifically marks active genes. While chromatin immunoprecipitation (ChIP) followed by next-generation sequencing (ChIP-seq) analyses are commonly performed in cell lines, only limited data are available from primary tumors. We therefore examined whether cancer-specific alterations in H3K27ac occupancy can be identified in primary rectal cancer. Tissue samples from primary rectal cancer and matched mucosa were obtained. ChIP-seq for H3K27ac was performed and differentially occupied regions were identified. The expression of selected genes displaying differential occupancy between tumor and mucosa were examined in gene expression data from an independent patient cohort. Differential expression of four proteins was further examined by immunohistochemistry. ChIP-seq for H3K27ac in primary rectal cancer and matched mucosa was successfully performed and revealed differential binding on 44 regions. This led to the identification of genes with increased H3K27ac, i.e., RIPK2, FOXQ1, KRT23, and EPHX4, which were also highly upregulated in primary rectal cancer in an independent dataset. The increased expression of these four proteins was confirmed by immunohistochemistry. This study demonstrates the feasibility of ChIP-seq-based epigenome mapping of primary rectal cancer and confirms the value of H3K27ac occupancy to predict gene expression differences."],["dc.identifier.doi","10.3390/cancers11081142"],["dc.identifier.pmid","31404997"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16348"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62383"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.relation.issn","2072-6694"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Epigenome Mapping Identifies Tumor-Specific Gene Expression in Primary Rectal Cancer"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]