scholarly journals The bromodomain and extra-terminal domain degrader MZ1 exhibits preclinical anti-tumoral activity in diffuse large B-cell lymphoma of the activated B cell-like type

2021 ◽  
Vol 2 (6) ◽  
pp. 586-601
Author(s):  
Chiara Tarantelli ◽  
Eleonora Cannas ◽  
Hillarie Ekeh ◽  
Carmelo Moscatello ◽  
Eugenio Gaudio ◽  
...  

Aim: Bromodomain and extra-terminal domain (BET) proteins are epigenetic readers that play a fundamental role in transcription regulation. Preclinical and early clinical evidence sustain BET targeting as an anti-cancer approach. BET degraders are chimeric compounds comprising of a BET inhibitor, which allows the binding to BET bromodomains, linked to a small molecule, binder for an E3 ubiquitin ligase complex, triggering BET proteins degradation via the proteasome. These degraders, called proteolysis-targeting chimeras (PROTACs), can exhibit greater target specificity compared to BET inhibitors and overcome some of their limitations, such as the upregulation of the BET proteins themselves. Here are presented data on the anti-tumor activity and the mechanism of action of the BET degrader MZ1 in diffuse large B cell lymphoma (DLBCL) of the activated B-cell like (ABC, ABC DLBCL), using a BET inhibitor as a comparison. Methods: Established lymphoma cell lines were exposed for 72 h to increasing doses of the compounds. Cell proliferation was evaluated by using an 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazoliumbromide (MTT) assay. Fluorescent-Activated Cell Sorter (FACS) analysis was performed to measure apoptotic activation and RNA sequencing (RNA-Seq) to study the transcriptional changes induced by the compounds. Results: MZ1, and not its negative control epimer cisMZ1, was very active with a median half maximal inhibitory concentration (IC50) of 49 nmol/L. MZ1 was more in vitro active than the BET inhibitor birabresib (OTX015). Importantly, MZ1 induced cell death in all the ABC DLBCL cell lines, while the BET inhibitor was cytotoxic only in a fraction of them. BET degrader and inhibitor shared partially similar changes at transcriptome level but the MZ1 effect was stronger and overlapped with that caused cyclin-dependent kinase 9 (CDK9) inhibition. Conclusions: The BET degrader MZ1 had strong cytotoxic activity in all the ABC DLBCL cell lines that were tested, and, at least in vitro, it elicited more profound effects than BET inhibitors, and encourages further investigations.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 294-294
Author(s):  
Enrico Derenzini ◽  
Patrizia Mondello ◽  
Yuxuan Liu ◽  
Mary Scallion ◽  
Zahra Asgari ◽  
...  

Abstract MYC overexpression is a poor prognostic predictor in Diffuse Large B-Cell Lymphoma (DLBCL). MYC-targeting with bromodomain and extraterminal protein family (BET) inhibitors is a promising strategy for the treatment of MYC-driven cancers, including lymphomas. However, preclinical and emerging data from early clinical trials demonstrated a modest antiproliferative activity in vitro and in vivo. We hypothesized that BET inhibition may induce feedback survival mechanisms preventing or attenuating cell death that could be exploited for designing future, more effective, combination strategies. In a high-throughput combinatorial drug screening experiment, we found that phosphatidylinositol 3-kinase (PI3K) pathway inhibitors enhanced the antiproliferative effects of BET inhibitors (JQ1, I-BET 151, CPI-203) with a strong class effect. JQ1 upregulated the mRNA expression of several upstream components of the PI3K pathway, including PIK3CA, PIK3R1, PDK1 in a large panel of DLBCL and Burkitt lymphoma cell lines. These effects translated in increased pathway activation as demonstrated by increased levels of the phosphorylated forms of downstream targets GSK3α/β, TSC2, P70S6K, and by increased concentrations of chemokines known to be regulated by PI3K in cell culture supernatants (CCL3 and CCL4). This effect was reversed by submicromolar doses of the PI3K inhibitor BKM-120. MYC silencing recapitulated the effects of BET inhibitors on PI3K pathway gene expression, activation and chemokine secretion. These data indicate that BET inhibition induces PI3K activation by a MYC-dependent feedback. We also observed transcriptional upregulation of the antiapoptotic gene Myeloid Leukemia 1 (MCL-1) following BET inhibition or MYC depletion, suggesting a second MYC-dependent mechanism. RNAi-mediated MCL-1 silencing or co-treatment with a small molecule MCL-1 inhibitor (UMI-77) enhanced the effects of BET inhibitors in DLBCL cell lines by inducing apoptosis. Using SILAC-based quantitative mass spectrometry, we found that BET inhibitors at submicromolar doses downregulated several E2 ubiquitin conjugating enzymes including UBE2C. RNAi mediated UBE2C knockdown induced MCL-1 upregulation in DLBCL cells. The enhanced in vitro effect of combining BETi and PI3Ki was reproduced in TMD8 mouse xenografts. To our knowledge, this is the first study demonstrating MYC-dependent regulation of the PI3K pathway, MCL-1 and the ubiquitin system upon BET inhibition. Our study revealed previously unknown mechanisms of action of BET inhibitors uncovering novel MYC-dependent survival feedback loops, and providing a framework for future combination strategies. Disclosures Zelenetz: Gilead Sciences: Research Funding.


2019 ◽  
Vol 116 (34) ◽  
pp. 16981-16986 ◽  
Author(s):  
Claudio Scuoppo ◽  
Jiguang Wang ◽  
Mirjana Persaud ◽  
Sandeep K. Mittan ◽  
Katia Basso ◽  
...  

To repurpose compounds for diffuse large B cell lymphoma (DLBCL), we screened a library of drugs and other targeted compounds approved by the US Food and Drug Administration on 9 cell lines and validated the results on a panel of 32 genetically characterized DLBCL cell lines. Dasatinib, a multikinase inhibitor, was effective against 50% of DLBCL cell lines, as well as against in vivo xenografts. Dasatinib was more broadly active than the Bruton kinase inhibitor ibrutinib and overcame ibrutinib resistance. Tumors exhibiting dasatinib resistance were commonly characterized by activation of the PI3K pathway and loss of PTEN expression as a specific biomarker. PI3K suppression by mTORC2 inhibition synergized with dasatinib and abolished resistance in vitro and in vivo. These results provide a proof of concept for the repurposing approach in DLBCL, and point to dasatinib as an attractive strategy for further clinical development in lymphomas.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5494-5494 ◽  
Author(s):  
Willy Berlier ◽  
Karine Aguera ◽  
Anne-Marie Chevrier ◽  
Fanny Gallix ◽  
Alexandra Traverse-Glehen ◽  
...  

Abstract L-asparaginase (L-ASPA) displays a strong clinical benefit in the treatment of acute lymphoblastic leukemia (ALL), where it is included in most of current chemotherapy regimen. L-ASPA depletes plasmatic asparagine (ASN), an amino acid essential for the proliferation of leukemic cells. Since these cells are deficient in asparagine synthetase (ASNS), they rely on external (plasmatic) source of ASN and can be starved to death by L-ASP treatment. Several studies evidenced the potential of ASN depletion to treat lymphomas. Indeed, many animal and human lymphoma cell lines have been shown to be sensitive to L-ASPA in vitro. In veterinary medicine, L-ASPA is routinely administered to treat effectively both feline and canine lymphomas (Wypig et al., 2013). L-ASPA regained attention in the treatment of human lymphomas since its adjunction in current chemotherapy regimens significantly improved the outcome of patients with NK/T cell lymphoma (Zou et al., 2014). Some studies also evidenced its benefit in combined chemo or monotherapy for the treatment of B-cell and T-cell lymphomas (Sun et al., 2006; Takahashi et al., 2010). In this study, we assessed the in vitro sensitivity to L-ASPA of 6 lymphoma cell lines and we analyzed ASNS expression in biopsies from 166 cases of lymphomas (130 B-cell lymphomas and 17 T-cell lymphomas). Sensitivity to L-ASPA (expressed as an IC50) was assessed in vitro by measuring the cell viability in the presence of various concentrations of E.coliL-ASPA. ASNS expression in biopsies (TMA, USBiomax, Rockville, MD) was assessed with a validated immunohistochemistry (IHC) method attributing a score to each tumor based on ASNS labeling intensity from 0 (no expression) to 3 (strong expression). Tumors expressing no/low ASNS (scores 0 and 1) were considered potentially sensitive to asparagine depletion. As shown in the following table, all cell lines were proved to be sensitive to L-ASPA. Their in vitrosensitivity exceeded cell lines MOLT-4 (ALL) and HL-60 (AML). Table 1Cell lineSensitivity to L-ASPA (IC50 in IU/mL)HuT-78 (Peripheral T-cell lymphoma,PTCL)0.11 ± 0.02Toledo (Diffuse large B-cell lymphoma, DLBCL)0.19 ± 0.03SU-DHL-8(Diffuse large B-cell lymphoma, DLBCL)0.10 ± 0.04SU-DHL-10(Diffuse large B-cell lymphoma, DLBCL)0.10 ± 0.01REC-1 (Mantle cell lymphoma, MCL)0.15 ± 0.03KHYG-1 (NK/T-cell lymphoma)0.16 ± 0.06MOLT-4 (acute lymphoid leukemia, ALL)0.19 ± 0.07HL-60 (acute myeloid leukemia, AML)0.23 ± 0.02 As shown in the following table, ASNS expression was null/low in 85% in the entire population of patients with B-cell lymphomas. Considering DLBCL, 63% of patients displayed no ASNS expression at all. ASNS expression was also null/low in 88% of patients with T-cell lymphomas (n=17). Table 2ASNS expression (IHC score)Type of lymphoma(% of cases)DLBCL (n=110)Others BCL (n=20)PTCL (n=3)Others TCL (n=14)MCL(n=3)Hodgkin (n=16)Negative (0)62,770,00,057,133,343,8Low positive (1)21,825,066,635,766,656,3Positive (2)7,35,033,37,10,00,0Highly positive (3)8,20,00,00,00,00,0 Globally, these results suggest that L-ASPA is potentially effective for the treatment of several lymphomas. Indeed, B-cell as well as T-cell lymphoma cell lines are sensitive to L-ASP in vitroand the majority of lymphoma tissues express no/low ASNS. Based on our results on ASNS expression in lymphoma biopsies, L-ASPA therapy may be beneficial for up to 85% of patients with DLBCL. Up to 90% of patients with other B-cell lymphomas or T-cell lymphomas may be sensitive to L-ASPA treatment as well. However, L-ASPA has only been used scarcely in the treatment of lymphomas despite promising clinical responses. Its well known serious side-effects (hypersensitivity, coagulation disorders, pancreatitis, and liver failure) render its use hazardous, particularly in older or frail patients. Therefore, the development of a new formulation of L-ASPA with safer profile has to be considered in order to allow the clinical development of L-ASPA in the treatment of aggressive lymphomas. Disclosures Berlier: ERYTECH: Employment, Equity Ownership. Aguera:ERYTECH: Employment. Chevrier:ERYTECH: Employment. Gallix:ERYTECH: Employment. Godfrin:ERYTECH Pharma: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.


2017 ◽  
Author(s):  
Neeraj Jain ◽  
Keenan Hartert ◽  
Saber Tadros ◽  
Warren Fiskus ◽  
Ondrej Havranek ◽  
...  

ABSTRACTThe activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) is characterized by the chronic activation of signaling initiated by immunoglobulin-μ (IgM). By analyzing DNA copy profiles of 1,000 DLBCLs, we identified gains of 18q21.2 as the most frequent genetic alteration in ABC-like DLBCL. We show that these alterations target the TCF4 (E2-2) transcription factor, and that over-expression of TCF4 leads to its occupancy on immunoglobulin gene enhancers and increased expression of IgM at the transcript and protein level. The TCF4 gene is one of the top BRD4-regulated genes in DLBCL. Using a BET proteolysis-targeting chimera (PROTAC) we show that TCF4 and IgM expression can be extinguished, and ABC-like DLBCL cells can be killed in vitro and in vivo. This highlights a novel genetic mechanism for promoting immunoglobulin signaling in ABC-like DLBCL and provides a functional rationale for the use of BET inhibitors in this disease.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xu-Wen Guan ◽  
Hua-Qing Wang ◽  
Wei-Wei Ban ◽  
Zhi Chang ◽  
Hai-Zhu Chen ◽  
...  

AbstractLoss of CD20 is a major obstacle for the retreatment of relapsed/refractory diffuse large B cell lymphoma (DLBCL) with Rituximab-associated regimens. Histone deacetylation causes gene silencing and inhibits CD20 expression. Chidamide is a novel inhibitor for histone deacetylases (HDACs). We hypothesize that Chidamide could overcome Rituximab-mediated down-regulation of CD20 and facilitate Rituximab-induced killing. In this study, we determine the mechanism of synergy of Chidamide with Rituximab in DLBCL using in vitro and in vivo models. We found that the levels of CD20 protein surface expression on five DLBCL cell lines were significantly and positively correlated with the sensitivities of cells to Rituximab. Treatment with Rituximab significantly reduced CD20 surface expression at the protein levels. RNA sequencing showed that Chidamide significantly increased expression of more than 2000 transcriptomes in DLBCL cells, around 1000 transcriptomes belong to the cell membrane and cell periphery pathways, including MS4A1. Chidamide significantly increased CD20 surface expression in DLBCL cell lines. Combination with Chidamide significantly synergized Rituximab-induced cell death in vitro and significantly inhibited tumour growth in DLBCL-bearing xenograft mice. A patient with relapsed/refractory DLBCL achieved a complete response after three cycles combined treatment with Chidamide and Rituximab. In conclusion, our data demonstrate for the first time that inhibition of HDACs by Chidamide significantly enhanced Rituximab-induced tumour growth inhibition in vitro and in vivo. We propose that CD20 surface expression should be used clinically to evaluate treatment response in patients with DLBCL. Chidamide is a promising sensitizer for the retreatment of DLBCL with Rituximab.


2019 ◽  
Vol 11 (497) ◽  
pp. eaav5599 ◽  
Author(s):  
Neeraj Jain ◽  
Keenan Hartert ◽  
Saber Tadros ◽  
Warren Fiskus ◽  
Ondrej Havranek ◽  
...  

The activated B cell (ABC-like) subtype of diffuse large B cell lymphoma (DLBCL) is characterized by chronic activation of signaling initiated by immunoglobulin μ (IgM). By analyzing the DNA copy number profiles of 1000 DLBCL tumors, we identified gains of 18q21.2 as the most frequent genetic alteration in ABC-like DLBCL. Using integrative analysis of matched gene expression profiling data, we found that the TCF4 (E2-2) transcription factor gene was the target of these alterations. Overexpression of TCF4 in ABC-like DLBCL cell lines led to its occupancy on immunoglobulin (IGHM) and MYC gene enhancers and increased expression of these genes at the transcript and protein levels. Inhibition of TCF4 activity with dominant-negative constructs was synthetically lethal to ABC-like DLBCL cell lines harboring TCF4 DNA copy gains, highlighting these gains as an attractive potential therapeutic target. Furthermore, the TCF4 gene was one of the top BRD4-regulated genes in DLBCL cell lines. BET proteolysis-targeting chimera (PROTAC) ARV771 extinguished TCF4, MYC, and IgM expression and killed ABC-like DLBCL cells in vitro. In DLBCL xenograft models, ARV771 treatment reduced tumor growth and prolonged survival. This work highlights a genetic mechanism for promoting immunoglobulin signaling in ABC-like DLBCL and provides a functional rationale for the use of BET inhibitors in this disease.


2011 ◽  
Vol 29 (15_suppl) ◽  
pp. 8061-8061
Author(s):  
H. A. Eradat ◽  
M. A. Eckardt ◽  
E. Dorfman ◽  
H. Hamidi ◽  
C. Ginther ◽  
...  

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2568-2568
Author(s):  
Yi Zhao ◽  
Yang Han ◽  
Juan Yang ◽  
Shunfeng Hu ◽  
Xin Wang

Abstract: Polo-like kinase 4 (PLK4) is a serine/threonine kinase that plays a critical role in regulating centriole duplication. PLK4 overexpression causes centriole amplification and genomic instability, which is the hallmark of cancer. Thus, PLK4 has been suggested as a tumor promoter role in solid malignancies. CFI-400945 is a highly selective small-molecule inhibitor of PLK4. CFI-400945 treatment results in centriole duplication defects, which leads to mitotic catastrophe and cell death. The antineoplastic effects of CFI-400945 have been reported in many cancers and this inhibitor has entered Phase I clinical trials for solid tumors. However, the role of PLK4 and cellular effects of CFI-40045 in hematological malignancies remains elusive. In the present study, we found that PLK4 expression is up-regulated at both transcriptional and translational levels in diffuse large B-cell lymphoma (DLBCL) cell lines (Fig. 1a, Fig. 1b). DLBCL patients displayed high protein levels of PLK4 as visualized by immunohistochemistry (Fig. 1c). In vitro, treatment of DLBCL cell lines with CFI-400945 induced a decrease in cell proliferation and an increase in cell apoptosis and a block at the G2-M transition in a dose-dependent manner (Fig. 1d, Fig. 1e, Fig. 1f). Furthermore, we found that the antineoplastic effects of CFI-400945 in DLBCL cell lines were due to the increased DNA damage, as observed by increased accumulation of γH2AX through phosphorylation of CHK1/CHK2 (Fig. 1g). Since PLK4 inhibition affects DNA damage, we next aimed to explore the effects of PLK4 expression on sensitivity of DNA damage-inducing drugs (e.g., doxorubicin). We found that silencing of PLK4 via shRNA improve the anti-tumor effects of doxorubicin in DLBCL cell lines (Fig. 1h, Fig. 1i). PLK4 inhibition in combination with doxorubicin significantly increased phosphorylation of H2AX compared to cells treated with doxorubicin alone (Fig. 1j). In summary, our data indicates that PLK4 is aberrantly expressed in DLBCL cell lines and tissues. Targeting PLK4 with the selective inhibitor CFI-400945 suppresses cell proliferation and induces apoptotic deaths and causes DNA damage in vitro. Our findings established PLK4 as a potential therapeutic target in DLBCL. Silencing of PLK4 expression induces accumulation of DNA damage and enhances the cytotoxic effects of doxorubicin. Thus, the levels of PLK4 may serve as a determinant of doxorubicin sensitivity and a predictive biomarker of the patients with DLBCL treated with R-CHOP based therapy. Figure 1 Disclosures No relevant conflicts of interest to declare.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Danxia Zhu ◽  
Cheng Fang ◽  
Wenting He ◽  
Chen Wu ◽  
Xiaodong Li ◽  
...  

We investigated the role of miR-181a in diffuse large B-cell lymphoma (DLBCL) and its potential target genes. miR-181a levels were lower in activated B-cell- (ABC-) like DLBCL cells than that in germinal center B-cell- (GCB-) like DLBCL cells. Overexpression of miR-181a in ABC-like DLBCL cell lines (OCI-LY10 and U2932) resulted in G0/G1 cell cycle arrest, increased apoptosis, and decreased invasiveness. miRNA target prediction programs (miRanda, TargetScan, and miRDB) identified caspase recruitment domain-containing protein 11 (CARD11) as a putative miR-181a target. CARD11 mRNA and protein levels were higher in the ABC-like DLBCL than that in GCB-like DLBCL. Moreover, CARD11 mRNA and protein levels were downregulated in the OCI-LY10 and U2932 cell lines overexpressing miR-181a. Dual luciferase reporter assays confirmed the miR-181a binding site in the CARD11 3′UTR region. OCI-LY10 and U2932 cells transfected with a CARD11 expression vector encoding miR-181a with a mutated binding site showed higher CARD11 protein levels, cell viability, G2/M phase cells, and invasiveness compared to those transfected with a wild-type CARD11 expression vector. Nude mice xenografted with OCI-LY10 cells with overexpressed wild-type miR-181a generated smaller tumors compared to those with overexpressed mutated binding site of CARD11 3′UTR and miR-181a. These results indicate that miR-181a inhibits ABC-like DLBCL by repressing CARD11.


2020 ◽  
Vol 52 (4) ◽  
pp. 401-410
Author(s):  
Mengyu Xi ◽  
Wan He ◽  
Bo Li ◽  
Jinfeng Zhou ◽  
Zhijian Xu ◽  
...  

Abstract Diffuse large B-cell lymphoma (DLBCL) is the most common category and disease entity of non-Hodgkin lymphoma. Osalmide and pterostilbene are natural products with anticancer activities via different mechanism. In this study, using a new synthetic strategy for the two natural products, we obtained the compound DCZ0801, which was previously found to have anti-multiple myeloma activity. We performed both in vitro and in vivo assays to investigate its bioactivity and explore its underlying mechanism against DLBCL cells. The results showed that DCZ0801 treatment gave rise to a dose- and time-dependent inhibition of cell viability as determined by CCK-8 assay and flow cytometry assay. Western blot analysis results showed that the expression of caspase-3, caspase-8, caspase-9 and Bax was increased, while BCL-2 and BCL-XL levels were decreased, which suggested that DCZ0801 inhibited cell proliferation and promoted intrinsic apoptosis. In addition, DCZ0801 induced G0/G1 phase arrest by downregulating the protein expression levels of CDK4, CDK6 and cyclin D1. Furthermore, DCZ0801 exerted an anti-tumor effect by down-regulating the expressions of p-PI3K and p-AKT. There also existed a trend that the expression of p-JNK and p-P38 was restrained. Intraperitoneal injection of DCZ0801 suppressed tumor development in xenograft mouse models. The preliminary metabolic study showed that DCZ0801 displayed a rapid metabolism within 30 min. These results demonstrated that DCZ0801 may be a new potential anti-DLBCL agent in DLBCL therapy.


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