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  • 1
    In: British Journal of Haematology, Wiley
    Abstract: The DNA damage response (DDR) is the cellular process of preserving an intact genome and is often deregulated in lymphoma cells. The ataxia telangiectasia and Rad3‐related (ATR) kinase is a crucial factor of DDR in the response to DNA single‐strand breaks. ATR inhibitors are agents that have shown considerable clinical potential in this context. We characterized the activity of the ATR inhibitor elimusertib (BAY 1895344) in a large panel of lymphoma cell lines. Furthermore, we evaluated its activity combined with the clinically approved PI3K inhibitor copanlisib in vitro and in vivo. Elimusertib exhibits potent anti‐tumour activity across various lymphoma subtypes, which is associated with the expression of genes related to replication stress, cell cycle regulation and, as also sustained by CRISPR Cas9 experiments, CDKN2A loss. In several tumour models, elimusertib demonstrated widespread anti‐tumour activity stronger than ceralasertib, another ATR inhibitor. This activity is present in both DDR‐proficient and DDR‐deficient lymphoma models. Furthermore, a combination of ATR and PI3K inhibition by treatment with elimusertib and copanlisib has in vitro and in vivo anti‐tumour activity, providing a potential new treatment option for lymphoma patients.
    Type of Medium: Online Resource
    ISSN: 0007-1048 , 1365-2141
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2023
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  • 2
    In: Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 22, No. 12_Supplement ( 2023-12-01), p. C144-C144
    Abstract: Background. PIM kinases (PIM1, PIM2, PIM3) are serine threonine kinases that function in multiple biological processes including cell cycle regulation, cell survival and proliferation. They also mediate resistance to anti-tumour agents comprising PI3K inhibitors. PIM1 overexpression and mutations are common in diffuse large B cell lymphoma (DLBCL) and PIM1 overexpression has been validated as a rational therapeutic target particularly in ABC and MCD subtypes. PIM1 overexpression is also found in mantle cell lymphoma (MCL). We investigated the pharmacological inhibition of PIM using the small molecule MEN1703/SEL24 in a large panel of lymphoma cell lines. Methods. Anti-proliferative activity was assessed by MTT assay at 72h: MEN1703/SEL24 was tested in 7 ABC-DLBCL, 19 germinal centre-B cell-like (GCB)-DLBCL, nine MCL, six marginal zone lymphoma (MZL), one primary mediastinal, four MZL ibrutinib-and PI3K-resistant models and one canine lymphoma. Cell cycle and apoptosis assays were done by flow cytometry. RNA-Seq was performed on two ABC- and two GCB-DLBCL cell lines treated with MEN1703/SEL24 or DMSO for 4, 8, 12h, followed by limma and functional annotation analysis with gene set enrichment analysis (GSEA). Results. MEN1703/SEL24 showed anti-proliferative activity in all lymphoma histotypes tested (IC50 median = 593 nM; range = 30 - 10,193 nM). MCL (IC50 median = 108 nM; range = 53 - 412 nM) and ABC-DLBCL (IC50median = 994 nM; range = 30 - 1756 nM) were the most sensitive histotypes; among them OCI-Ly-10 (30 nM) and OCI-Ly-3 (142 nM) had mutated PIM1. GCB-DLBCLs comprised the least sensitive cell lines (IC50 median = 961 nM; range = 252 - 10,193 nM) accounting for 8/11 cell lines with IC50 in the upper percentile. More importantly, MEN1703/SEL24 was active in MZL cell lines with acquired resistance to idelalisib, copanlisib and ibrutinib (IC50 median = 367 nM; range = 273 - 410 nM). MEN1703/SEL24 induced apoptosis in 6/6 cell lines and minor G1 arrest in 1/6 cell lines. In DLBCL cell lines more sensitive to MEN1703/SEL24 treatment, RNA-Seq and GSEA revealed differential modulation of immune, MYC and E2F targets. Conclusions. MEN1703/SEL24 shows robust preclinical activity in B cell lymphomas of different histotypes. RNA-Seq indicates that MEN1703/SEL24 modulates the transcriptome of highly responsive DLBCL cell lines differently from poorly responsive cells, providing novel clues to mechanisms involved in sensitivity to PIM inhibitors and supporting a potential for clinical development in this indication. Citation Format: Afua A. Mensah, Alessandro Ghiringhelli, Giulio Sartori, Filippo Spriano, Chiara Tarantelli, Luciano Cascione, Andrea Rinaldi, Alberto A. Arribas, Daniela Bellarosa, Monica Binaschi, Francesco Bertoni. MEN1703/SEL24, a potent PIM inhibitor, demonstrates promising anti-tumour activity in activated B cell like diffuse large B cell lymphoma, mantle cell lymphoma and marginal zone lymphoma cells [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C144.
    Type of Medium: Online Resource
    ISSN: 1538-8514
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2023
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  • 3
    In: Haematologica, Ferrata Storti Foundation (Haematologica), Vol. 107, No. 11 ( 2022-04-28), p. 2685-2697
    Abstract: PI3Kδ inhibitors are active in patients with lymphoid neoplasms and a first series of them have been approved for the treatment of multiple types of B-cell lymphoid tumors, including marginal zone lymphoma (MZL). The identification of the mechanisms underlying either primary or secondary resistance is fundamental to optimize the use of novel drugs. Here we present a model of secondary resistance to PI3Kδ inhibitors obtained by prolonged exposure of a splenic MZL cell line to idelalisib. The VL51 cell line was kept under continuous exposure to idelalisib. The study included detailed characterization of the model, pharmacological screens, silencing experiments, and validation experiments on multiple cell lines and on clinical specimens. VL51 developed resistance to idelalisib, copanlisib, duvelisib, and umbralisib. An integrative analysis of transcriptome and methylation data highlighted an enrichment of upregulated transcripts and low-methylated promoters in resistant cells, including IL-6/STAT3- and PDGFRA-related genes and surface CD19 expression, alongside the repression of the let-7 family of miRNA, and miR-125, miR-130, miR-193 and miR-20. The IL-6R blocking antibody tocilizumab, the STAT3 inhibitor stattic, the LIN28 inhibitor LIN1632, the PDGFR inhibitor masitinib and the anti-CD19 antibody drug conjugate loncastuximab tesirine were active compounds in the resistant cells as single agents and/or in combination with PI3Kδ inhibition. Findings were validated on additional in vitro lymphoma models and on clinical specimens. A novel model of resistance obtained from splenic MZL allowed the identification of therapeutic approaches able to improve the antitumor activity of PI3Kδ inhibitors in B-cell lymphoid tumors.
    Type of Medium: Online Resource
    ISSN: 1592-8721 , 0390-6078
    Language: Unknown
    Publisher: Ferrata Storti Foundation (Haematologica)
    Publication Date: 2022
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  • 4
    In: Blood Cancer Discovery, American Association for Cancer Research (AACR), Vol. 1, No. 3_Supplement ( 2020-11-01), p. PO-46-PO-46
    Abstract: Background: PI3Kδ is expressed in B cells and has a central role in the B-cell receptor signaling. Copanlisib is a highly selective PI3Kδ and PI3Kα inhibitor, and it is currently under clinical development in indolent lymphomas including marginal zone lymphoma (MZL). Copanlisib is Food and Drug Administration (FDA) approved for the treatment of patients with relapsed or refractory follicular lymphoma. Nevertheless, a subset of patients can eventually relapse due to acquired resistance. A better understanding of resistance mechanisms could help to design improved therapies; hence, we generated MZL cell lines resistant to copanlisib. Materials and Methods: Cells were kept on copanlisib (IC90) until acquisition of resistance (RES) or with no drug (parental, PAR). Stable resistance was confirmed by MTT assay after 3 weeks of drug-free culture. Multidrug resistance phenotype was ruled out by confirming sensitivity to vincristine. Cells underwent transcriptome profiling (RNA-Seq) and immunophenotypic analysis. Results: The RES models were obtained from VL51 cell line with over 50-fold times higher IC50s than PAR counterparts. Of note, the copanlisib-resistant lines showed decreased sensitivity to other PI3K inhibitors such as duvelisib (50-fold) and idelalisib (5-fold) and to the BTK inhibitor ibrutinib (15-fold), suggesting that the mechanism observed here might drive resistance to other downstream B-cell receptor inhibitors. Gene expression profiles of RES showed the upregulation of cytokine signaling (IL1A, IL1B, CXCR4), NFkB (LTA, TNF), MAPK (RASGRP4, RASGRP2), and JAK-STAT (STAT3, JAK3) signaling pathways and negative regulators of apoptosis (CD44, JUN). Conversely, repressed genes in RES were involved in cell adhesion (ITGA4, ITGB1), antigen presentation (HLAs), and IFN response (PARP12, GBP6). Consistent with the overexpression of antiapoptotic signaling genes, RES cells exhibited also resistance to the BCL2-inhibitor venetoclax, either as a single as in combination with copanlisib. Flow cytometry confirmed the CXCR4 upregulation and the downregulation of CD49d (ITGA4), paired with reduced CD20 and CD81 surface expression. In accordance, addition of a CXCR4 inhibitor overcame resistance to copanlisib. Conclusions: We created a model of secondary resistance to the PI3K inhibitor copanlisib, derived from an MZL cell line. This model will help in clarifying mechanisms of resistance to the drug and to evaluate alternative therapeutic approaches. Indeed, we already identified novel potential targets, such as IL1 and CXCR4, that might be exploited in overcoming resistance to copanlisib and are worthy of further investigation. Citation Format: Alberto J. Arribas, Sara Napoli, Luciano Cascione, Eugenio Gaudio, Roberta Bordone-Pittau, Marilia Barreca, Giulio Sartori, Chiara Tarantelli, Filippo Spriano, Andrea Rinaldi, Anastasios Stathis, Georg Stussi, Davide Rossi, Emanuele Zucca, Francesco Bertoni. Mechanisms of resistance to the PI3K inhibitor copanlisib in marginal zone lymphoma [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-46.
    Type of Medium: Online Resource
    ISSN: 2643-3230 , 2643-3249
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
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  • 5
    In: Blood Cancer Discovery, American Association for Cancer Research (AACR), Vol. 1, No. 3_Supplement ( 2020-11-01), p. PO-07-PO-07
    Abstract: Introduction: Gains affecting chromosome 11 are recurrent events in lymphomas. The 11q24.3 gain occurs in 25% of diffuse large B-cell lymphoma (DLBCL), and it is associated with the overexpression of two ETS transcription factors, ETS1 and FLI1 (Blood 2013). Here, we have focused on the latter to identify the network of FLI1 regulated genes in GCB DLBCL. Methods: GCB and ABC cell lines. Gene expression data were obtained from public datasets GSE98588, phs001444.v2.p1, GSE95013, GSE10846, and EGAS00001002606. Anti-FLI1 antibody - ChIP Grade (ab15289). ChIP-Seq for FLI1 paired with transcriptome analysis (RNA-Seq) after FLI1 silencing (siRNA) was performed. Sequencing was carried out using the NextSeq 500 (Illumina). Detection of peaks was analyzed using HOMER (v2.6); differential expressed genes were identified using moderated t-test (limma R-package) and functionally annotated with g:Profiler. Results: The analysis of DLBCL cell lines showed that FLI1 protein levels were higher in GCB (n=12) than ABC (n=8) cell lines and was more commonly expressed at high levels in GCB (n= 414) than ABC (n= 518) DLBCL clinical specimens. Integration of identified binding sites from ChIP-Seq with RNA-Seq from GCB DLBCL cell lines (OCI-Ly1 and VAL) with genetically silenced FLI1 allowed the identification of putative FLI1 direct targets. The FLI1 negatively regulated genes included tumor-suppressor genes involved in negative regulation of cell cycle and p53 cascade. Among the FLI1 positively regulated targets we found genes annotated for immune response, MYC targets and B cell receptor, TNF-alpha and IL2 signaling pathways. Of note, direct targets of FLI1 overlapped with those genes regulated by ETS1, the other transcription factor co-gained in DLBCL, suggesting a functional convergence within the ETS family. ASB2 was downregulated after FLI1 silencing and had FLI1 binding sites in both promoter region and distal enhancer regions. Furthermore, ASB2 is known to promote NF-kB activation in T-cell acute lymphoblastic leukemia and might be an essential gene in DLBCL cells according to a genetic screening. Consistently, ASB2 gene silencing was toxic in GCB DLBCL lines. We observed inhibition of NF-kB pathway by a strong protein downregulation of RELB, along with increased IκBα upon ASB2 and FLI1 silencing, although with no differences in NF-kB2 levels. Only FLI1 silencing caused downregulation of NF-kB1 and RELA protein levels, but no effect on these two proteins was observed upon ASB2 silencing. These results indicate that FLI1 regulates either the classic NF-kB pathway at transcriptional level or the alternative pathway, via ASB2, in GCB DLBCL. Conclusions: FLI1 is expressed at higher levels in GCB than ABC DLBCL and directly regulates a network of biologically crucial genes and processes in DLBCL, contributing to the regulation of NF-kB pathway in GCB DLBCL. ASB2, a subunit of a multimeric E3 ubiquitin ligase complex, is a novel FLI1 direct target, and its inhibition might represent a therapeutic approach for GCB DLBCL. Citation Format: Giulio Sartori, Sara Napoli, Luciano Cascione, Elaine Y.L. Chung, Valdemar Priebe, Alberto J. Arribas, Andrea Rinaldi, Michela Dall'Angelo, Mattia Forcato, Silvio Bicciato, Margot Thome, Francesco Bertoni. The FLI1 direct target ASB2 promotes NF-KB pathway activation in diffuse large B-cell lymphoma of the germinal center B-cell type [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-07.
    Type of Medium: Online Resource
    ISSN: 2643-3230 , 2643-3249
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
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  • 6
    In: Journal of Clinical Medicine, MDPI AG, Vol. 12, No. 2 ( 2023-01-04), p. 399-
    Abstract: Inhibitors of phosphatidylinositol 3-kinase (PI3K) and Bruton tyrosine kinase (BTK) represent a recognized option for the treatment of patients affected by indolent B cell lymphomas. However, small molecules as single agents show limited success in their ability in inducing complete responses, with only partial remission achieved in most patients, suggesting the need for combination therapies. IRAK4 is a protein kinase downstream of the Toll-like receptor signaling (TLR), a driver pathway of secondary tumor° resistance in both hematological and solid tumor malignancies. Activation of IRAK4 upon TLRs and IL-1 receptor (IL-1R) stimulation and through the adaptor protein MYD88 initiates a signaling cascade that induces cytokine and survival factor expression mediated by the transcription factor NF-κB. MYD88-L265P encoding mutations occur in diffuse large B-cell lymphomas, in lymphoplasmacytic lymphomas and in few marginal zone lymphomas (MZL). The IRAK4 inhibitor emavusertib (CA-4948) has shown early safety and clinical activity in lymphoma and leukemia patients. In this preclinical study, we assessed emavusertib effectiveness in MZL, both as single agent and in combination with targeted agents, with a particular focus on its capability to overcome resistance to BTK and PI3K inhibitors. We showed that the presence of MYD88 L265P mutation in bona fide MZL cell lines confers sensitivity to the IRAK4 inhibitor emavusertib as single agent. Emavusertib-based combinations improved the sensitivity of MZL cells to BTK and PI3K inhibitors, including cells with a secondary resistance to these agents. Emavusertib exerted its activity via inhibition of NF-κB signaling and induction of apoptosis. Considering the early safety data from clinical trials, our study identifies the IRAK4 inhibitor emavusertib as a novel compound to be explored in trials for patients with MYD88-mutated indolent B cell lymphomas as single agent and as combination partner with BTK or PI3K inhibitors in unselected populations of patients.
    Type of Medium: Online Resource
    ISSN: 2077-0383
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
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  • 7
    In: Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 22, No. 12_Supplement ( 2023-12-01), p. B170-B170
    Abstract: Background. Nemtabrutinib is a reversible, ATP competitive tyrosine kinase inhibitor of BTK and of several other kinases, including LYN and MEK1 (Reiff et al, Cancer Discov 2018). Nemtabrutinib has shown preclinical and clinical activity in chronic lymphocytic leukemia (CLL), also against tumors bearing mutations affecting the C481 amino acid of BTK (Reiff et al, Cancer Discov 2018; Eradat et al, ICML 2023), which is commonly mutated in patients treated with 1st and 2nd generation inhibitors such as ibrutinib, acalabrutinib, zanubrutinib (Thompson & Tam, Blood 2023). Based on these data, a phase 3 trial is comparing the drug against chemo-immunotherapy in untreated-CLL patients (NCT05624554). Phase 1/2 studies are currently exploring nemtabrutinib in various B-cell lymphomas as single-agent (NCT05673460, NCT04728893) and combined with the ROR1-targeting antibody drug conjugate zilovertamab vedotin (NCT05458297). Due to the ability of nemtabrutinib to block multiple kinases, we exposed a large series of lymphoma cell lines to nemtabrutinib to understand the lymphomas that might most benefit. Methods. Nemtabrutinib (MedChemExpress) was assessed for its anti-proliferative activity at 72h across 54 cell lines, comprising germinal-center B-cell like (GCB) DLBCL (n.=18), activated B-cell like (ABC) DLBCL (n.=8), mantle cell lymphoma (MCL) (n.=10), marginal zone lymphoma (MZL) (n.=6), CLL (n.=2), plus other two derived from B- and eight from T-cell (n.=8) lymphomas. Results. The median IC50 for nemtabrutinib was 1.4 µM (95%CI, 0.8-2.3 µM) across all 54 lymphoma cell lines tested. Higher activity was found in B (median-IC50, 1.1 µM) compared to T (median IC50, 22.6 µM) cell lymphomas. Strong anti-lymphoma activity was observed in CLL cell lines (median IC50, 389 nM), MCL (median IC50, 627 nM), in one primary mediastinal B cell lymphoma (815 nM) and one canine diffuse large B-cell lymphoma cell line (389 nM). No difference was seen between ABC (median IC50, 1 µM) and GCB (median IC50, 1.2 µM) DLBCL. In DLBCL, nemtabrutinib anti-tumor activity was not affected by the presence of inactive TP53, BCL2 and/or MYC translocations.  Taking advantage of publicly available ibrutinib data, we observed that nemtabrutinib and the 1st generation BTK inhibitor behaved similarly across 45 lymphoma cell lines (Pearson correlation r=0.5, P=0.001), especially in MCL (r=0.8, P=0.005) and ABC-DLBCL (r=0.75, P=0.039), but not in GCB-DLBCL, in which only nemtabrutinib was active. Further analyses integrating baseline transcriptome and mutational data are underway. Conclusions. Nemtabrutinib showed anti-tumor activity across B-cell lymphomas, higher in some histotypes (including MCL, CLL). The pattern of anti-tumor activity was only partially overlapping by what achieved by the BTK inhibitor ibrutinib: while MCL and ABC-DLBCL responded similarly, activity in GCB-DLBCL was seen only with nemtabrutinib. Citation Format: Giulio Sartori, Filippo Spriano, Luciano Cascione, Chiara Tarantelli, Alberto J. Arribas, Luca Aresu, Davide Rossi, Giovanna Damia, Massimo Broggini, Francesco Bertoni. The in vitro anti-tumor activity of the multi-kinase inhibitor nemtabrutinib (ARQ-531, MK-1026) is seen across multiple B-cell lymphoma subtypes, only partially overlapping with what achieved by single BTK inhibition [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B170.
    Type of Medium: Online Resource
    ISSN: 1538-8514
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2023
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  • 8
    In: Cancer Immunology Research, American Association for Cancer Research (AACR), Vol. 10, No. 12 ( 2022-12-02), p. 1525-1541
    Abstract: During melanoma metastasis, tumor cells originating in the skin migrate via lymphatic vessels to the sentinel lymph node (sLN). This process facilitates tumor cell spread across the body. Here, we characterized the innate inflammatory response to melanoma in the metastatic microenvironment of the sLN. We found that macrophages located in the subcapsular sinus (SS) produced protumoral IL1α after recognition of tumoral antigens. Moreover, we confirmed that the elimination of LN macrophages or the administration of an IL1α-specific blocking antibody reduced metastatic spread. To understand the mechanism of action of IL1α in the context of the sLN microenvironment, we applied single-cell RNA sequencing to microdissected metastases obtained from animals treated with the IL1α-specific blocking antibody. Among the different pathways affected, we identified STAT3 as one of the main targets of IL1α signaling in metastatic tumor cells. Moreover, we found that the antitumoral effect of the anti-IL1α was not mediated by lymphocytes because Il1r1 knockout mice did not show significant differences in metastasis growth. Finally, we found a synergistic antimetastatic effect of the combination of IL1α blockade and STAT3 inhibition with stattic, highlighting a new immunotherapy approach to preventing melanoma metastasis.
    Type of Medium: Online Resource
    ISSN: 2326-6066 , 2326-6074
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2022
    detail.hit.zdb_id: 2732517-9
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  • 9
    In: Journal of Experimental & Clinical Cancer Research, Springer Science and Business Media LLC, Vol. 40, No. 1 ( 2021-11-11)
    Abstract: Diffuse large B-cell lymphoma (DLBCL) comprises at least two main biologically distinct entities: germinal center B-cell (GCB) and activated B-cell (ABC) subtype. Albeit sharing common lesions, GCB and ABC DLBCL present subtype-specific oncogenic pathway perturbations. ABC DLBCL is typically characterized by a constitutively active NF-kB. However, the latter is seen in also 30% of GCB DLBCL. Another recurrent lesion in DLBCL is an 11q24.3 gain, associated with the overexpression of two ETS transcription factors, ETS1 and FLI1. Here, we showed that FLI1 is more expressed in GCB than ABC DLBCL and we characterized its transcriptional network. Methods Gene expression data were obtained from public datasets GSE98588, phs001444.v2.p1, GSE95013 and GSE10846. ChIP-Seq for FLI1 paired with transcriptome analysis (RNA-Seq) after FLI1 silencing (siRNAs) was performed. Sequencing was carried out using the NextSeq 500 (Illumina). Detection of peaks was done using HOMER (v2.6); differential expressed genes were identified using moderated t-test (limma R-package) and functionally annotated with g:Profiler. ChIP-Seq and RNA-Seq data from GCB DLBCL cell lines after FLI1 downregulation were integrated to identify putative direct targets of FLI1. Results Analysis of clinical DLBCL specimens showed that FLI1 gene was more frequently expressed at higher levels in GCB than in ABC DLBCL and its  protein levels were higher in GCB than in ABC DLBCL cell lines . Genes negatively regulated by FLI1 included tumor suppressor genes involved in negative regulation of cell cycle and hypoxia. Among positively regulated targets of FLI1, we found genes annotated for immune response, MYC targets, NF-κB and BCR signaling and NOTCH pathway genes. Of note, direct targets of FLI1 overlapped with genes regulated by ETS1, the other transcription factor gained at the 11q24.3 locus in DLBCL, suggesting a functional convergence within the ETS family. Positive targets of FLI1 included the NF-κB-associated ASB2 a putative essential gene for DLBCL cell survival. ASB2 gene downregulation was toxic in GCB DLBCL cell lines and induced NF-κB inhibition via downregulation of RelB and increased IκBα. Additionally, downregulation of FLI1 , but not ASB2 , caused reduction of NF-κB1 and RelA protein levels. Conclusions We conclude that FLI1 directly regulates a network of biologically crucial genes and processes in GCB DLBCL. FLI1 regulates both the classical NF-κB pathway at the transcriptional level, and the alternative NF-κB pathway, via ASB2. FLI1 and ASB2 inhibition represents a potential novel therapeutic approach for GCB DLBCL.
    Type of Medium: Online Resource
    ISSN: 1756-9966
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
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  • 10
    In: eJHaem, Wiley, Vol. 3, No. 3 ( 2022-08), p. 764-774
    Abstract: Inhibitors of the Bromo‐ and Extra‐Terminal domain (BET) family proteins have strong preclinical antitumor activity in multiple tumor models, including lymphomas. Limited single‐agent activity has been reported in the clinical setting. Here, we have performed a pharmacological screening to identify compounds that can increase the antitumor activity of BET inhibitors in lymphomas. The germinal center B‐cell like diffuse large B‐cell lymphoma (DLBCL) cell lines OCI‐LY‐19 and WSU‐DLCL2 were exposed to 348 compounds given as single agents at two different concentrations and in combination with the BET inhibitor birabresib. The combination partners included small molecules targeting important biologic pathways such as PI3K/AKT/MAPK signaling and apoptosis, approved anticancer agents, kinase inhibitors, epigenetic compounds. The screening identified a series of compounds leading to a stronger antiproliferative activity when given in combination than as single agents: the histone deacetylase (HDAC) inhibitors panobinostat and dacinostat, the mTOR (mechanistic target of rapamycin) inhibitor everolimus, the ABL/SRC (ABL proto‐oncogene/SRC proto oncogene) inhibitor dasatinib, the AKT1/2/3 inhibitor MK‐2206, the JAK2 inhibitor TG101209. The novel finding was the benefit given by the addition of the LRRK2 inhibitor LRRK2‐IN‐1, which was validated in vitro and in vivo. Genetic silencing demonstrated that LRRK2 sustains the proliferation of lymphoma cells, a finding paired with the association between high expression levels and inferior outcome in DLBCL patients. We identified combinations that can improve the response to BET inhibitors in lymphomas, and LRRK2 as a gene essential for lymphomas and as putative novel target for this type of tumors.
    Type of Medium: Online Resource
    ISSN: 2688-6146 , 2688-6146
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2022
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