scholarly journals The ubiquitin ligase RNF5 determines acute myeloid leukemia growth and susceptibility to histone deacetylase inhibitors

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ali Khateb ◽  
Anagha Deshpande ◽  
Yongmei Feng ◽  
Darren Finlay ◽  
Joo Sang Lee ◽  
...  

AbstractAcute myeloid leukemia (AML) remains incurable, largely due to its resistance to conventional treatments. Here, we find that increased abundance of the ubiquitin ligase RNF5 contributes to AML development and survival. High RNF5 expression in AML patient specimens correlates with poor prognosis. RNF5 inhibition decreases AML cell growth in culture, in patient-derived xenograft (PDX) samples and in vivo, and delays development of MLL-AF9–driven leukemogenesis in mice, prolonging their survival. RNF5 inhibition causes transcriptional changes that overlap with those seen upon histone deacetylase (HDAC)1 inhibition. RNF5 induces the formation of K29 ubiquitin chains on the histone-binding protein RBBP4, promoting its recruitment to and subsequent epigenetic regulation of genes involved in AML maintenance. Correspondingly, RNF5 or RBBP4 knockdown enhances AML cell sensitivity to HDAC inhibitors. Notably, low expression of both RNF5 and HDAC coincides with a favorable prognosis. Our studies identify an ERAD-independent role for RNF5, demonstrating that its control of RBBP4 constitutes an epigenetic pathway that drives AML, and highlight RNF5/RBBP4 as markers useful to stratify patients for treatment with HDAC inhibitors.

2020 ◽  
Author(s):  
Ali Khateb ◽  
Anagha Deshpande ◽  
Yongmei Feng ◽  
Joo Sang Lee ◽  
Ikrame Lazar ◽  
...  

ABSTRACTAcute myeloid leukemia (AML) remains incurable, largely due to its resistance to conventional treatments. Here, we found that increased expression and abundance of the ubiquitin ligase RNF5 contributes to AML development and survival. High RNF5 expression in AML patients correlated with poor prognosis. RNF5 inhibition decreased AML cell growth in culture and in vivo, and blocked development of MLL-AF9–driven leukemogenesis in mice, prolonging their survival. RNF5 inhibition led to transcriptional changes that overlapped with those seen upon HDAC1 inhibition. RNF5 induced the formation of K29 ubiquitin chains on the histone-binding protein RBBP4, promoting its recruitment and subsequent epigenetic regulation of genes involved in AML development and maintenance. Correspondingly, RNF5 or RBBP4 knockdown enhanced the sensitivity of AML cells to histone deacetylase (HDAC) inhibitors. Notably, low expression of RNF5 and HDAC coincided with a favorable prognosis. Our studies identified ERAD-independent role for RNF5, demonstrating that its control of RBBP4 constitutes an epigenetic pathway that drives AML while highlighting RNF5/RBBP4 as markers to stratify patients for treatment with HDAC inhibitors.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 31-32
Author(s):  
Ali Khateb ◽  
Anagha Deshpande ◽  
Yongmei Feng ◽  
Ikrame Lazar ◽  
Joo Sang Lee ◽  
...  

Acute myeloid leukemia (AML) remains an incurable blood cancer largely due to rapid emergence of resistance to conventional treatments. Thus, new therapeutic modalities are greatly needed to halt AML development. Here, using genetic and xenograft mouse models, we reveal that inhibition of the ubiquitin ligase RNF5 in human AML cell lines and in MLL-AF9-driven AML severely decreased the leukemogenic potential of those cells and prolonged survival of model leukemic mice. These findings suggest the possibility that targeting a single gene, namely RNF5, could effectively inhibit different AML subtypes. We initially focused on RNF5 as its expression is upregulated in AML patient cohorts as well as in AML-derived cell lines compared with normal hematopoietic cells. Furthermore, high RNF5 expression in AML patient specimens correlated with poor prognosis, relapse and short overall patient survival. By contrast, specimens from AML patients who responded to therapy exhibited low RNF5 levels. In vitro, RNF5 loss impaired the clonogenic potential of MLL-AF9-transduced bone marrow cells and markedly attenuated growth and survival of AML but not CML or T-ALL cell lines, in which RNF5 is also highly expressed. High-throughput screen and bioinformatics analysis identified RNF5 and ER-associated degradation (ERAD) components, as augmenting AML cell sensitivity to histone deacetylase (HDAC) inhibition. Indeed, inhibition of RNF5 sensitized AML cells to HDAC inhibitors. Correspondingly, a favorable prognosis was observed in AML patients exhibiting low expression of RNF5 and HDAC. Collectivity, our studies identify a potential new therapeutic modality based on targeting RNF5 to inhibit AML and suggest that RNF5 expression could serve as a prognostic marker and means to stratify patients for treatment with HDAC inhibitors. Disclosures Ofran: AbbVie: Membership on an entity's Board of Directors or advisory committees. Vuori:Bionano Genomics: Membership on an entity's Board of Directors or advisory committees.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuejie Jiang ◽  
Ling Jiang ◽  
Jiaying Cheng ◽  
Fang Chen ◽  
Jinle Ni ◽  
...  

Abstract Background Epigenetic dysregulation plays important roles in leukemogenesis and the progression of acute myeloid leukemia (AML). Histone acetyltransferases (HATs) and histone deacetylases (HDACs) reciprocally regulate the acetylation and deacetylation of nuclear histones. Aberrant activation of HDACs results in uncontrolled proliferation and blockade of differentiation, and HDAC inhibition has been investigated as epigenetic therapeutic strategy against AML. Methods Cell growth was assessed with CCK-8 assay, and apoptosis was evaluated by flow cytometry in AML cell lines and CD45 + and CD34 + CD38- cells from patient samples after staining with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI). EZH2 was silenced with short hairpin RNA (shRNA) or overexpressed by lentiviral transfection. Changes in signaling pathways were detected by western blotting. The effect of chidamide or EZH2-specific shRNA (shEZH2) in combination with adriamycin was studied in vivo in leukemia-bearing nude mouse models. Results In this study, we investigated the antileukemia effects of HDAC inhibitor chidamide and its combinatorial activity with cytotoxic agent adriamycin in AML cells. We demonstrated that chidamide suppressed the levels of EZH2, H3K27me3 and DNMT3A, exerted potential antileukemia activity and increased the sensitivity to adriamycin through disruption of Smo/Gli-1 pathway and downstream signaling target p-AKT in AML cells and stem/progenitor cells. In addition to decreasing the levels of H3K27me3 and DNMT3A, inhibition of EZH2 either pharmacologically by chidamide or genetically by shEZH2 suppressed the activity of Smo/Gli-1 pathway and increased the antileukemia activity of adriamycin against AML in vitro and in vivo. Conclusions Inhibition of EZH2 by chidamide has antileukemia activity and increases the chemosensitivity to adriamycin through Smo/Gli-1 pathway in AML cells (Fig. 5). These findings support the rational combination of HDAC inhibitors and chemotherapy for the treatment of AML.


Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3847-3856 ◽  
Author(s):  
Takahiro Maeda ◽  
Masayuki Towatari ◽  
Hiroshi Kosugi ◽  
Hidehiko Saito

Abstract Histone deacetylase inhibitors (HDACIs) have been used to focus on the effects of inducing gene expression through the acetylation of histones which results in chromatin remodeling. The study explored whether HDACIs could induce the expression of costimulatory/adhesion molecules on acute myeloid leukemia (AML) cells, thereby effectively inducing tumor immunity. The expression of CD80, CD86, human leukocyte antigen (HLA)-DR, HLA-ABC, and intracellular adhesion molecule–1 (ICAM-1) was tested in human AML cell lines after the addition of HDACI, sodium butyrate (SB). Generally, increased expression of CD86 was observed by SB treatment in a majority of cell lines, and ICAM-1 was expressed in fewer cell lines. Essentially the same results were obtained using other HDACIs such as FR901228, trichostatin A, and trapoxin A. Quantitation of transcripts of CD86 accompanied with RNA synthesis inhibition assay and nuclear run-on assay revealed that SB up-regulates the CD86 expression transcriptionally. Furthermore, chromatin immunoprecipitation experiments showed that HDACI treatment caused remarkable acetylation on histone H3 and H4 at CD86 promoter chromatin in vivo. In 30 clinical AML samples, CD86 expression was significantly increased (P < .001) by SB treatment, and the expression of HLA-DR and ICAM-1 was moderately increased (P < .05) by SB treatment. Finally, the allogeneic mixed leukocyte reaction (allo-MLR) against HL60 cells pretreated with SB was enhanced 4-fold compared with allo-MLR obtained with non-treated HL60 cells. These results suggest that the immunotherapeutic use of HDACIs may become a novel tool for treatment of AML.


2016 ◽  
Vol 59 (21) ◽  
pp. 9942-9959 ◽  
Author(s):  
Jesse J. McClure ◽  
Cheng Zhang ◽  
Elizabeth S. Inks ◽  
Yuri K. Peterson ◽  
Jiaying Li ◽  
...  

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5383-5383
Author(s):  
Montserrat Perez-Salvia ◽  
Aldaba Eneko ◽  
Vara Yosu ◽  
Fabre Myriam ◽  
Ferrer Cristina ◽  
...  

Abstract Histone deacetylase 6 (HDAC6) is a protein modifier that is an increasingly attractive pharmacological target. Interestingly, the observation that the HDAC6 knock-out mouse is not lethal, in contrast to those undergoing complete loss of class I, II and III HDACs, suggests that specific HDAC6 inhibitors may be better tolerated than pan-HDAC inhibitors or drugs that target the other HDAC classes. In this regard, the compound ACY-1215 (Rocilinostat), the described selective HDAC6 inhibitors, is undergoing clinical trials for the treatment of multiple myeloma. Taking into account the previous information about HDAC6 inhibitor structures, the structural differences between HDAC6 and other HDAC isoforms and also the structural information of other developed HDAC inhibitors, we have previously designed and synthesized a new potential HDAC6 selective inhibitor, QTX125 with growth inhibitory effects in mantle cell lymphoma (MCL) cell lines, mouse models and ex vivo treatment of primary samples obtained from patients with MCL. Herein, we have extended these findings to show that the newly identified HDAC6 inhibitor QTX125 is also able to inhibit the growth of preclinical models of other B-cell lymphomas such as follicular lymphoma and Burkitt's cell lymphoma, but also of acute acute myeloid leukemia. In addition beyond a-tubulin, a well known HDAC6 target, we have developed a pharmacological and proteomic screening to identify other proteins modified by HDAC6 that can contribute to the described lymphoma and leukemia phenotypes. Disclosures Eneko: Quimatryx: Employment. Yosu:Quimatryx: Employment. Myriam:Oncomatryx: Employment. Cristina:Oncomatryx: Employment. González-Barca:Roche: Speakers Bureau; Celtrion: Consultancy; Gilead: Consultancy; janssen: Consultancy, Speakers Bureau. Fernando:Quimatryx: Consultancy.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 889-889
Author(s):  
Hassiba Chaib ◽  
Thomas Prebet ◽  
Audrey Restouin ◽  
Remy Castellano ◽  
Sandrine Opi ◽  
...  

Abstract Recent studies have highlighted the importance of epigenetic modifications in the pathogenesis of Acute Myeloid Leukemia (AML). This results have been confirmed by the activity of new drug like DNA demethylating agents and histone deacetylase (HDAC) inhibitors in both in vivo and in vitro studies. Recently, Chaetocin, a natural fungal compound, has been identified as the first specific inhibitor of the histone methyltransferase SU(VAR)3–9 which plays a role in heterochromatin gene silencing. In this study, we decided to evaluate Chaetocin as a therapeutic agent in AML in vitro and to explore the related mechanisms. We show that Chaetocin induce dramatic cell death at nanomolar concentrations in U937 and HL60 (97.2% ± 0.4 and 91.6% ± 9 cell death at 100 nM chaetocin, respectively), and to a lesser extend in K562 (67.3% ± 1.6 cell death at 100 nM chaetocin), cell cultures. Cell death occurred at 24 h incubation time which correlated with induction of apoptosis as assessed by Annexin V/7-AAD staining and activation of downstream executioner caspase-3/7. Using transcription low-density array and quantitative RT- PCR, Chaetocin was showed to up-regulate gene transcription such as of the cell cycle inhibitor p21/WAF1 consistent with a role for the targeted SU(VAR)3–9 in heterochromatin gene silencing. In agreement with the recent report of Chaetocin being a promising new antimyeloma agent acting via imposition of oxidative stress, intracellular levels of oxidative species were increased in Chaetocin treated U937 cells in a time- and dose-dependent manner that correlated with induction of cell death. Furthermore, incubation of cells with N-acetyl cysteine, a cell-permeable precursor of intracellular glutathione reductant, prevented chaetocin-induced accumulation of oxidative species, transcription of selected genes (e.g. p21/WAF1), activation of caspase-3, and cell death. Finally, Chaetocin was found to increase the antileukemia activity of HDAC inhibitors and Aracytin, and thus appears as a promising agent for further study as a potential anti-AML therapeutic. Preliminary results obtained in vivo in xenograft models and ex vivo, using blasts of a panel of patients with AML, will be presented.


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