scholarly journals NSD2 Regulates Pro-Metastatic Gene PTP4A3 through Chromatin Remodeling in Multiple Myeloma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 28-28
Author(s):  
Phyllis SY Chong ◽  
Jing Yuan Chooi ◽  
Julia Lim ◽  
Wee-Joo Chng
Keyword(s):  
Chromatin Remodeling ◽  
Conflicts Of Interest ◽  
Interaction Analysis ◽  
Myeloma Cell ◽  
Protein Protein Interaction ◽  
Downstream Target ◽  
Poor Survival Outcome ◽  
Oncogenic Driver ◽  
Novel Strategy ◽  
Targeting Effect

Nuclear receptor-binding SET domain 2 (NSD2) is the primary oncogenic driver and represent a good druggable target due to its universal overexpression in t(4;14) MM. However, given the challenges in the development of small molecule inhibitors against NSD2, we took on a discovery approach to characterize NSD2 interactome as an alternative strategy to target NSD2. We employed SILAC-based mass-spectrometry coupled with gene ontology analysis to uncover the spectrum of NSD2-interacting proteins which are relevant in t(4;14) MM. Validation using in silico protein-protein interaction analysis and immunoprecipitation confirmed that SMARCA2, a bromodomain-containing chromatin remodeler, interacts with NSD2 independent of the SWI/SNF complex. SMARCA2 is primarily expressed in t(4;14) cell lines, and functional assays indicated that dual inhibition of SMARCA2 and NSD2 impairs growth of t(4;14)+ cells. Next, we performed RNA sequencing which led to the identification of PTP4A3 as a downstream target of NSD2 that is co-regulated by SMARCA2. Mechanistically, SMARCA2 is required for the recruitment of NSD2 to PTP4A3 promoter, leading to a transcriptionally permissive state for expression. Importantly, upregulation of PTP4A3 is sufficient for the activation of MYC, which is crucial for t(4;14) myelomagenesis. PFI-3, which belongs to the class of bromodomain and extra-terminal motif protein inhibitors (BETi), displaced SMARCA2 and NSD2 occupancy from PTP4A3 promoter, and selectively inhibited t(4;14) myeloma cell viability. Interestingly, PFI-3 treatment did not perturb the levels of NSD2 nor SMARCA2, rather, the targeting effect is achieved through their occupancy on oncogenes. Finally, high expression of NSD2 and SMARCA2 were predictive of poor survival outcome in a large cohort of myeloma patients. Collectively, we demonstrated a proof-of-concept of how histone modifying enzyme and chromatin remodeling complex cooperatively caused an altered epigenetic state in myelomagenesis through the regulation of an important myeloma gene. Our study proposed that the pharmacological inhibition of SMARCA2 may represent a novel strategy to target t(4;14) myeloma cells using BETi and also explore as combinational therapy with anti-myeloma agents that are currently in the clinics. Disclosures No relevant conflicts of interest to declare.

scholarly journals Nuclear Heparanase Regulates Chromatin Remodeling, Gene Expression and PTEN Tumor Suppressor Function

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2038
Author(s):  
Rada Amin ◽  
Kaushlendra Tripathi ◽  
Ralph D. Sanderson
Keyword(s):  
Tumor Suppressor ◽  
Chromatin Remodeling ◽  
Target Genes ◽  
Myeloma Cell ◽  
Chromatin Accessibility ◽  
Tumor Suppressor Function ◽  
Suppressor Activity ◽  
Downstream Target ◽  
Suppressor Function ◽  
Chromatin Opening

Heparanase (HPSE) is an endoglycosidase that cleaves heparan sulfate and has been shown in various cancers to promote metastasis, angiogenesis, osteolysis, and chemoresistance. Although heparanase is thought to act predominantly extracellularly or within the cytoplasm, it is also present in the nucleus, where it may function in regulating gene transcription. Using myeloma cell lines, we report here that heparanase enhances chromatin accessibility and confirm a previous report that it also upregulates the acetylation of histones. Employing the Multiple Myeloma Research Foundation CoMMpass database, we demonstrate that patients expressing high levels of heparanase display elevated expression of proteins involved in chromatin remodeling and several oncogenic factors compared to patients expressing low levels of heparanase. These signatures were consistent with the known function of heparanase in driving tumor progression. Chromatin opening and downstream target genes were abrogated by inhibition of heparanase. Enhanced levels of heparanase in myeloma cells led to a dramatic increase in phosphorylation of PTEN, an event known to stabilize PTEN, leading to its inactivity and loss of tumor suppressor function. Collectively, this study demonstrates that heparanase promotes chromatin opening and transcriptional activity, some of which likely is through its impact on diminishing PTEN tumor suppressor activity.

Induction of CRBN(Cereblon) mRNA Expression by Baicalein

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 5025-5025
Author(s):  
Zi Ma ◽  
Rui bo Zhang ◽  
Li He ◽  
Chao ping Xu ◽  
Ding xin Zhou ◽  
...  
Keyword(s):  
Maintenance Therapy ◽  
Mrna Expression ◽  
Conflicts Of Interest ◽  
Myeloma Cell ◽  
Dependent Manner ◽  
Myeloma Cells ◽  
Novel Strategy ◽  
Induced Apoptosis ◽  
Cell Inhibition ◽  
Effective Drugs

Abstract Abstract 5025 The CRBN gene that encodes the cereblon protein is found on the short arm at position p26. 3 of human chromosome 3. Cereblon is a primary target of thalidomide teratogenicity and required for the anti-myeloma activity of lenalidomide and pomalidomide. CRBN depletion myeloma cells become highly resistant to both lenalidomide and pomalidomide. Baicalein, a component of Scutellaria radix from HLJDT, not only suppressed proliferation and induced apoptosis of myeloma cells by down-regulating interleukin −6(IL-6) and XIAP gene expression, but also inhibited the signaling cascades mediated by IL-6 and facilitated myeloma cell inhibition induced by dexamethasone. In clinic, we found that treatment of thlidomide- or lenalidomide-resistant myeloma patients by applying Huang-Lian-Jie-Du-Tang (HLJDT) can induce hematological remission. The precise molecular mechanism of HLJDT exerts its anti-tumor effects remains unclear. Here, by RT-PCR, we demonstrated that treatment of U266 cells and primary myeloma cells with 20μM baicalein can induce CRBN mRNA expression in time-dependent manner. As lenalidomide and thlidomide are effective drugs for maintenance therapy with the advantage of oral administration. It was particularly active in patients with higher cereblon expression. Thus, the combination of HLJDT with thlidomide or lenalidomide may be a novel strategy of maintenance therapy for myeloma patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Actin-Related Protein 6 (Arp6) Influences Double-Strand Break Repair in Yeast

2021 ◽  
Vol 1 (2) ◽  
pp. 225-238
Author(s):  
Mohsen Hooshyar ◽  
Daniel Burnside ◽  
Maryam Hajikarimlou ◽  
Katayoun Omidi ◽  
Alexander Jesso ◽  
...  
Keyword(s):  
Dna Damage ◽  
Chromatin Remodeling ◽  
Genetic Interaction ◽  
Interaction Analysis ◽  
Strand Break ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Dna Damaging Agents ◽  
Repair Efficiency ◽  
Chromosomal Breaks

DNA double-strand breaks (DSBs) are the most deleterious form of DNA damage and are repaired through non-homologous end-joining (NHEJ) or homologous recombination (HR). Repair initiation, regulation and communication with signaling pathways require several histone-modifying and chromatin-remodeling complexes. In budding yeast, this involves three primary complexes: INO80-C, which is primarily associated with HR, SWR1-C, which promotes NHEJ, and RSC-C, which is involved in both pathways as well as the general DNA damage response. Here we identify ARP6 as a factor involved in DSB repair through an RSC-C-related pathway. The loss of ARP6 significantly reduces the NHEJ repair efficiency of linearized plasmids with cohesive ends, impairs the repair of chromosomal breaks, and sensitizes cells to DNA-damaging agents. Genetic interaction analysis indicates that ARP6, MRE11 and RSC-C function within the same pathway, and the overexpression of ARP6 rescues rsc2∆ and mre11∆ sensitivity to DNA-damaging agents. Double mutants of ARP6, and members of the INO80 and SWR1 complexes, cause a significant reduction in repair efficiency, suggesting that ARP6 functions independently of SWR1-C and INO80-C. These findings support a novel role for ARP6 in DSB repair that is independent of the SWR1 chromatin remodeling complex, through an apparent RSC-C and MRE11-associated DNA repair pathway.

scholarly journals Targeting AKT/mTOR and Bcl-2 for Autophagic and Apoptosis Cell Death in Lung Cancer: Novel Activity of a Polyphenol Compound

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 534
Author(s):  
Sucharat Tungsukruthai ◽  
Onrapak Reamtong ◽  
Sittiruk Roytrakul ◽  
Suchada Sukrong ◽  
Chanida Vinayanwattikun ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Proteomic Analysis ◽  
Interaction Analysis ◽  
Time Dependent ◽  
The Novel ◽  
Protein Protein Interaction ◽  
Autophagy Induction ◽  
Acidic Vesicle

Autophagic cell death (ACD) is an alternative death mechanism in resistant malignant cancer cells. In this study, we demonstrated how polyphenol stilbene compound PE5 exhibits potent ACD-promoting activity in lung cancer cells that may offer an opportunity for novel cancer treatment. Cell death caused by PE5 was found to be concomitant with dramatic autophagy induction, as indicated by acidic vesicle staining, autophagosome, and the LC3 conversion. We further confirmed that the main death induction caused by PE5 was via ACD, since the co-treatment with an autophagy inhibitor could reverse PE5-mediated cell death. Furthermore, the defined mechanism of action and upstream regulatory signals were identified using proteomic analysis. Time-dependent proteomic analysis showed that PE5 affected 2142 and 1996 proteins after 12 and 24 h of treatment, respectively. The crosstalk network comprising 128 proteins that control apoptosis and 25 proteins involved in autophagy was identified. Protein–protein interaction analysis further indicated that the induction of ACD was via AKT/mTOR and Bcl-2 suppression. Western blot analysis confirmed that the active forms of AKT, mTOR, and Bcl-2 were decreased in PE5-treated cells. Taken together, we demonstrated the novel mechanism of PE5 in shifting autophagy toward cell death induction by targeting AKT/mTOR and Bcl-2 suppression.

scholarly journals Distinct Compartmentalization of NF-κB Activity in Crypt and Crypt-Denuded Lamina Propria Precedes and Accompanies Hyperplasia and/or Colitis following Bacterial Infection

2011 ◽  
Vol 80 (2) ◽  
pp. 753-767 ◽  
Author(s):  
Parthasarathy Chandrakesan ◽  
Ishfaq Ahmed ◽  
Anisha Chinthalapally ◽  
Pomila Singh ◽  
Shanjana Awasthi ◽  
...  
Keyword(s):  
Lamina Propria ◽  
Dietary Intervention ◽  
Inbred Mice ◽  
Content Type ◽  
Downstream Target ◽  
Inflammatory Protein ◽  
Chemotactic Protein ◽  
Extracellular Signal ◽  
Crypt Hyperplasia ◽  
Novel Strategy

ABSTRACTCitrobacter rodentiuminduces transmissible murine colonic hyperplasia (TMCH) and variable degrees of inflammation and necrosis depending upon the genetic background. UtilizingC. rodentium-induced TMCH in C3H/HeNHsd inbred mice, we observed significant crypt hyperplasia on days 3 and 7 preceding active colitis. NF-κB activity in the crypt-denuded lamina propria (CLP) increased within 24 h postinfection, followed by its activation in the crypts at day 3, which peaked by day 7. Increases in interleukin-α1 (IL-1α), IL-12(p40), and macrophage inflammatory protein 1α (MIP-1α) paralleled NF-κB activation, while increases in IL-1α/β, IL-6/IL-12(p40)/granulocyte colony-stimulating factor (G-CSF)/keratinocyte-derived chemokine (KC)/monocyte chemotactic protein 1 (MCP-1), and MIP-1α followed NF-κB activation leading to significant recruitment of neutrophils to the colonic mucosa and increased colonic myeloperoxidase (MPO) activity. Phosphorylation of the crypt cellular and nuclear p65 subunit at serines 276 and 536 led to functional NF-κB activation that facilitated expression of its downstream target, CXCL-1/KC, during TMCH. Distinct compartmentalization of phosphorylated extracellular signal-regulated kinase 1 and 2 ([ERK1/2] Thr180/Tyr182) and p38 (Thr202/Tyr204) in the CLP preceded increases in the crypts. Inhibition of ERK1/2 and p38 suppressed NF-κB activity in both crypts and the CLP. Dietary administration of 6% pectin or 4% curcumin inC. rodentium-infected mice also inhibited NF-κB activity and blocked CD3, F4/80, IL-1α/β, G-CSF/MCP-1/KC, and MPO activity in the CLP while not affecting NF-κB activity in the crypts. Thus, distinct compartmentalization of NF-κB activity in the crypts and the CLP regulates crypt hyperplasia and/or colitis, and dietary intervention may be a novel strategy to modulate NF-κB-dependent protective immunity to facilitate crypt regeneration followingC. rodentium-induced pathogenesis.

Protein–protein interaction analysis using an affinity peptide tag and hydrophilic polystyrene plate

2007 ◽  
Vol 128 (2) ◽  
pp. 354-361 ◽  
Author(s):  
Y KUMADA ◽  
C ZHAO ◽  
R ISHIMURA ◽  
H IMANAKA ◽  
K IMAMURA ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Interaction Analysis ◽  
Protein Protein Interaction ◽  
Polystyrene Plate ◽  
Affinity Peptide ◽  
Peptide Tag
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