scholarly journals Metabolic convergence on lipogenesis in RAS, BCR-ABL, and MYC-driven lymphoid malignancies

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Daniel F. Liefwalker ◽  
Meital Ryan ◽  
Zhichao Wang ◽  
Khyatiben V. Pathak ◽  
Seema Plaisier ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
De Novo ◽  
Metabolic Profiles ◽  
Human Cell Lines ◽  
Murine Models ◽  
Lymphoid Malignancies ◽  
Transgenic Murine Models

Abstract Background Metabolic reprogramming is a central feature in many cancer subtypes and a hallmark of cancer. Many therapeutic strategies attempt to exploit this feature, often having unintended side effects on normal metabolic programs and limited efficacy due to integrative nature of metabolic substrate sourcing. Although the initiating oncogenic lesion may vary, tumor cells in lymphoid malignancies often share similar environments and potentially similar metabolic profiles. We examined cells from mouse models of MYC-, RAS-, and BCR-ABL-driven lymphoid malignancies and find a convergence on de novo lipogenesis. We explore the potential role of MYC in mediating lipogenesis by 13C glucose tracing and untargeted metabolic profiling. Inhibition of lipogenesis leads to cell death both in vitro and in vivo and does not induce cell death of normal splenocytes. Methods We analyzed RNA-seq data sets for common metabolic convergence in lymphoma and leukemia. Using in vitro cell lines derived in from conditional MYC, RAS, and BCR-ABL transgenic murine models and oncogene-driven human cell lines, we determined gene regulation, metabolic profiles, and sensitivity to inhibition of lipogenesis in lymphoid malignancies. We utilize preclinical murine models and transgenic primary model of T-ALL to determine the effect of lipogenesis blockade across BCR-ABL-, RAS-, and c-MYC-driven lymphoid malignancies. Statistical significance was calculated using unpaired t-tests and one-way ANOVA. Results This study illustrates that de novo lipid biogenesis is a shared feature of several lymphoma subtypes. Using cell lines derived from conditional MYC, RAS, and BCR-ABL transgenic murine models, we demonstrate shared responses to inhibition of lipogenesis by the acetyl-coA carboxylase inhibitor 5-(tetradecloxy)-2-furic acid (TOFA), and other lipogenesis inhibitors. We performed metabolic tracing studies to confirm the influence of c-MYC and TOFA on lipogenesis. We identify specific cell death responses to TOFA in vitro and in vivo and demonstrate delayed engraftment and progression in vivo in transplanted lymphoma cell lines. We also observe delayed progression of T-ALL in a primary transgenic mouse model upon TOFA administration. In a panel of human cell lines, we demonstrate sensitivity to TOFA treatment as a metabolic liability due to the general convergence on de novo lipogenesis in lymphoid malignancies driven by MYC, RAS, or BCR-ABL. Importantly, cell death was not significantly observed in non-malignant cells in vivo. Conclusions These studies suggest that de novo lipogenesis may be a common survival strategy for many lymphoid malignancies and may be a clinically exploitable metabolic liability. Trial registration This study does not include any clinical interventions on human subjects.

scholarly journals Metabolic Convergence on Lipogenesis in RAS, BCR-ABL, and MYC-driven Lymphoid Malignancies

2020 ◽  
Author(s):  
Daniel Liefwalker ◽  
Meital Ryan ◽  
Ian Lai ◽  
Adriane Mosley ◽  
Gabrielle Dewson ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Subjects ◽  
Trial Registration ◽  
Metabolic Profiles ◽  
Murine Models ◽  
Clinical Interventions ◽  
Lymphoid Malignancies ◽  
Transgenic Murine Models

Abstract Background Metabolic re-programming is a central feature in many cancer subtypes and a hallmark of cancer. Many therapeutic strategies attempt to exploit this feature, although often having unintended side effects on normal metabolic programs and limited efficacy due to integrative nature of metabolic substrate sourcing. Although the initiating oncogenic lesion may vary, in lymphoid malignancies tumor cells often share similar environments and potentially similar metabolic profiles. Methods We searched publicly available data sets for common metabolic convergence in lymphoma and leukemia. Using in vitro cell lines derived in from conditional MYC, RAS, and BCR-ABL transgenic murine models we examine metabolic profiles of lipogenesis. We then utilize preclinical murine models and transgenic primary model of T-ALL to determine the effect of lipogenesis blockade across BCR-ABL, RAS, and c-MYC-driven lymphoid malignancies. Statistical significance was calculated using unpaired T tests and one-way ANOVA. Results We find that de novo lipid biogenesis is a shared feature of several lymphoma subtypes. Using cell lines derived in from conditional MYC, RAS, and BCR-ABL transgenic murine models we demonstrate shared responses to inhibition of lipogenesis by the acetyl-coA carboxylase inhibitor 5-(Tetradecloxy)-2-furic Acid (TOFA). We identify specific cell death responses to TOFA in vitro and in vivo and demonstrate delayed engraftment and progression in vivo in transplanted lymphoma cell lines. We also observed delayed progression of T-ALL in a primary transgenic mouse model upon TOFA administration. In a panel of human cell lines, we demonstrate sensitivity to TOFA treatment as a feature of MYC high expressing lymphoma cell lines. Conclusions These studies indicate that inhibition of lipogenesis may be a common survival strategy for many lymphomas and that high MYC expression is predictive of sensitivity to blockade of fatty acid synthesis. Trial Registration This study does not include any clinical interventions on human subjectsTrial RegistrationThis study does not include any clinical interventions on human subjects

scholarly journals IMMU-14. ONCOLYTIC VIRUS EXPRESSING A POSITIVE IMMUNE CHECKPOINT MODULATOR AS A THERAPEUTIC APPROACH FOR DIPG

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi122-vi122
Author(s):  
Virginia Laspidea ◽  
Montse Puigdelloses ◽  
Ignacio Iñigo-Marco ◽  
Marc Garcia-Moure ◽  
Iker Ausejo ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cell Death ◽  
Cell Lines ◽  
Oncolytic Virus ◽  
Murine Models ◽  
Antitumoral Effect ◽  
Infected Cells

Abstract Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor, being the leading cause of pediatric death caused by cancer. We previously showed that administration of the oncolytic virus Delta-24-RGD to DIPG murine models was safe and led to an increase in the median survival of these animals. However, not all the animals responded, underscoring the need to improve this therapy. In order to increase the antitumoral effect of the virus, we have engineered Delta-24-RGD with the costimulatory ligand 4-1BBL (Delta24-ACT). 4-1BB is a costimulatory receptor that promotes the survival and expansion of activated T cells, and the generation and maintenance of memory CD8+ T cells. In this project, we evaluated the oncolytic effect of Delta24-ACT and the antitumor immune response in DIPG murine models. In vitro, Delta24-ACT was able to infect and induce cell death in a dose-dependent manner in murine DIPG cell lines. In addition, Delta24-ACT was able to replicate in these tumor cells and to express viral proteins. Moreover, infected cells expressed 41BBL in their membranes. Delta24-ACT could induce immunogenic cell death due to an increased secretion of ATP and calreticulin translocation to the membrane of infected cells (in no-infected cells it located in the ER), DAMPs that can trigger the immune response activation. In vivo, Delta24-ACT demonstrated to be safe in all the tested doses and was able to induce a significant increase in the median survival of the treated animals. Moreover, long-term survivors display immunological memory. Delta24-ACT treatment led to antitumoral effect in DIPG murine cell lines in vitro. Of significance, we have demonstrated that in vivo administration of Delta24-ACT is safe and results in an enhanced antitumor effect. Future in vivo studies will explore the underlying immune mechanism of the virus.

scholarly journals P06.01 Delta24-ACT oncolytic adenovirus as a therapeutic approach for DIPG

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii36-iii36
Author(s):  
V Laspidea ◽  
M Puigdelloses ◽  
M García-Moure ◽  
I Iñigo-Marco ◽  
J Gallego ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Cell Lines ◽  
In Vivo Studies ◽  
Immunogenic Cell Death ◽  
Murine Models ◽  
Antitumoral Effect ◽  
Infected Cells

Abstract BACKGROUND Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor, being the leading cause of pediatric death caused by cancer. We previously showed that administration of the oncolytic virus Delta-24-RGD to DIPG murine models was safe and led to an increase in the median survival of these animals. However, not all the animals responded, underscoring the need to improve this therapy. In order to increase the antitumoral effect of the virus, we have engineered Delta-24-RGD with the costimulatory ligand 4-1BBL (Delta24-ACT). 4-1BB is a costimulatory receptor that promotes the survival and expansion of activated T cells, and the generation and maintenance of memory CD8+ T cells. In this project, we evaluated the oncolytic effect of Delta24-ACT and the antitumor immune response in DIPG murine models. MATERIALS AND METHODS We use the NP53 and XFM murine DIPG cell lines. Flow cytometry was used to assess cell infectivity and ligand expression. We analyzed viral replication using a method based in hexon detection, and viral cytotoxic effect using the MTS assay. For immunogenic cell death analysis, we measured ATP secretion by a luminometric assay and calreticulin location by flow cytometry and immunofluorescence. For in vivo studies, cells and virus were injected in the pons of the mice, using the screw-guided system. RESULTS In vitro, Delta24-ACT was able to infect and induce cell death in a dose-dependent manner in murine DIPG cell lines. In addition, Delta24-ACT was able to replicate in these tumor cells and to express viral proteins. Moreover, infected cells expressed 41BBL in their membranes. Delta24-ACT could induce immunogenic cell death due to an increased secretion of ATP and calreticulin translocation to the membrane of infected cells (in no-infected cells it located in the ER), DAMPs that can trigger the immune response activation. In vivo, Delta24-ACT demonstrated to be safe in all the tested doses and was able to induce a significant increase in the median survival of the treated animals. Moreover, long-term survivors display immunological memory. CONCLUSIONS Delta24-ACT treatment led to antitumoral effect in DIPG murine cell lines in vitro. Of significance, we have demonstrated that in vivo administration of Delta24-ACT is safe and results in an enhanced antitumor effect. Future in vivo studies will explore the underlying immune mechanism of the virus.

scholarly journals Sarcoma IL-12 overexpression facilitates NK cell immunomodulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mary Jo Rademacher ◽  
Anahi Cruz ◽  
Mary Faber ◽  
Robyn A. A. Oldham ◽  
Dandan Wang ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Lines ◽  
Nk Cell ◽  
Autologous Tumor ◽  
Murine Models ◽  
Lentiviral Transduction ◽  
Ifn Γ ◽  
Human Sarcoma

AbstractInterleukin-12 (IL-12) is an inflammatory cytokine that has demonstrated efficacy for cancer immunotherapy, but systemic administration has detrimental toxicities. Lentiviral transduction eliciting IL-12-producing human sarcoma for autologous reintroduction provides localized delivery for both innate and adaptive immune response augmentation. Sarcoma cell lines and primary human sarcoma samples were transduced with recombinant lentivirus engineering expression of human IL-12 (hu-IL-12). IL-12 expressing sarcomas were assessed in vitro and in vivo following implantation into humanized NSG and transgenic human IL-15 expressing (NSG.Tg(Hu-IL-15)) murine models. Lentiviral transduction (LV/hu-IL-12) of human osteosarcoma, Ewing sarcoma and rhabdomyosarcoma cell lines, as well as low-passage primary human sarcomas, engendered high-level expression of hu-IL-12. Hu-IL-12 demonstrated functional viability, eliciting specific NK cell-mediated interferon-γ (IFN-γ) release and cytotoxic growth restriction of spheroids in vitro. In orthotopic xenograft murine models, the LV/hu-IL-12 transduced human sarcoma produced detectable IL-12 and elicited an IFN-γ inflammatory immune response specific to mature human NK reconstitution in the NSG.Tg(Hu-IL-15) model while restricting tumor growth. We conclude that LV/hu-IL-12 transduction of sarcoma elicits a specific immune reaction and the humanized NSG.Tg(Hu-IL-15) xenograft, with mature human NK cells, can define in vivo anti-tumor effects and systemic toxicities. IL-12 immunomodulation through autologous tumor transduction and reintroduction merits exploration for sarcoma treatment.

scholarly journals Therapeutic evaluation of palbociclib and its compatibility with other chemotherapies for primary and recurrent nasopharyngeal carcinoma

2020 ◽  
Author(s):  
zhichao xue ◽  
Vivian Wai Yan Lui ◽  
Yongshu Li ◽  
Jia Lin ◽  
Chanping You ◽  
...  
Keyword(s):  
Cell Death ◽  
Nasopharyngeal Carcinoma ◽  
Cell Lines ◽  
Chemotherapeutic Drugs ◽  
Induce Cell Cycle Arrest ◽  
Ki 67 ◽  
Concurrent Treatment ◽  
Xenograft Models

Abstract Background: Recent genomic analyses revealed that druggable molecule targets were detectable in approximately 6% of patients with nasopharyngeal carcinoma (NPC). However, a dependency on dysregulated CDK4/6–cyclinD1 pathway signaling is an essential event in the pathogenesis of NPC. In this study, we aimed to evaluate the therapeutic efficacy of a specific CDK4/6 inhibitor, palbociclib, and its compatibility with other chemotherapeutic drugs for the treatment of NPC by using newly established xenograft models and cell lines derived from primary, recurrent, and metastatic NPC. Methods: We evaluated the efficacies of palbociclib monotherapy and concurrent treatment with palbociclib and cisplatin or suberanilohydroxamic acid (SAHA) in NPC cell lines and xenograft models. RNA sequencing was then used to profile the drug response–related pathways. Palbociclib-resistant NPC cell lines were established to determine the potential use of cisplatin as a second-line treatment after the development of palbociclib resistance. We further examined the efficacy of palbociclib treatment against cisplatin-resistant NPC cells. Results: In NPC cells, palbociclib monotherapy was confirmed to induce cell cycle arrest in the G1 phase in vitro . Palbociclib monotherapy also had significant inhibitory effects in all six tested NPC tumor models in vivo , as indicated by substantial reductions in the total tumor volumes and in Ki-67 proliferation marker expression. In NPC cells, concurrent palbociclib treatment mitigated the cytotoxic effect of cisplatin in vitro . Notably, concurrent treatment with palbociclib and SAHA synergistically promoted NPC cell death both in vitro and in vivo . This combination also further inhibited tumor growth by inducing autophagy-associated cell death. NPC cell lines with induced palbociclib or cisplatin resistance remained sensitive to treatment with cisplatin or palbociclib, respectively. Conclusions: Our study findings provide essential support for the use of palbociclib as an alternative therapy for NPC and increase awareness of the effective timing of palbociclib administration with other chemotherapeutic drugs. Our results provide a foundation for the design of first-in-human clinical trials of palbociclib regimens in patients with NPC.

scholarly journals Anticancer Activity of Cynomorium coccineum

Cancers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 354 ◽  
Author(s):  
Mouna Sdiri ◽  
Xiangmin Li ◽  
William Du ◽  
Safia El-Bok ◽  
Yi-Zhen Xie ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Anticancer Activity ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cell Cycle Progression ◽  
Cycle Progression

The extensive applications of Cynomorium species and their rich bioactive secondary metabolites have inspired many pharmacological investigations. Previous research has been conducted to examine the biological activities and numerous interesting pharmaceutical activities have been reported. However, the antitumor activities of these species are unclear. To understand the potential anticancer activity, we screened Cynomorium coccineum and Cynomorium songaricum using three different extracts of each species. In this study, the selected extracts were evaluated for their ability to decrease survival rates of five different cancer cell lines. We compared the cytotoxicity of the three different extracts to the anticancer drug vinblastine and one of the most well-known medicinal mushrooms Amaurederma rude. We found that the water and alcohol extracts of C. coccineum at the very low concentrations possessed very high capacity in decreasing the cancer cells viability with a potential inhibition of tumorigenesis. Based on these primitive data, we subsequently tested the ethanol and the water extracts of C. coccineum, respectively in in vitro and in vivo assays. Cell cycle progression and induction of programmed cell death were investigated at both biological and molecular levels to understand the mechanism of the antitumor inhibitory action of the C. coccineum. The in vitro experiments showed that the treated cancer cells formed fewer and smaller colonies than the untreated cells. Cell cycle progression was inhibited, and the ethanol extract of C. coccineum at a low concentration induced accumulation of cells in the G1 phase. We also found that the C. coccineum’s extracts suppressed viability of two murine cancer cell lines. In the in vivo experiments, we injected mice with murine cancer cell line B16, followed by peritoneal injection of the water extract. The treatment prolonged mouse survival significantly. The tumors grew at a slower rate than the control. Down-regulation of c-myc expression appeared to be associated with these effects. Further investigation showed that treatment with C. coccineum induced the overexpression of the tumor suppressor Foxo3 and other molecules involved in inducing autophagy. These results showed that the C. coccineum extract exerts its antiproliferative activity through the induction of cell death pathway. Thus, the Cynomorium plants appear to be a promising source of new antineoplastic compounds.

scholarly journals Viral Cross-Class Serpin Inhibits Vascular Inflammation and T Lymphocyte Fratricide; A Study in Rodent Models In Vivo and Human Cell Lines In Vitro

PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e44694 ◽  
Author(s):  
Kasinath Viswanathan ◽  
Ilze Bot ◽  
Liying Liu ◽  
Erbin Dai ◽  
Peter C. Turner ◽  
...  
Keyword(s):  
Cell Lines ◽  
T Lymphocyte ◽  
Human Cell ◽  
Vascular Inflammation ◽  
Rodent Models ◽  
Human Cell Lines

Purified, Fermented, Extract of Triticum Aestivum Has Significant Independent Lymphomacidal Activity and Augments the Activity of Rituximab

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2857-2857
Author(s):  
Laura Newell ◽  
Joseph Tuscano ◽  
Robert o'Donnell ◽  
Yunpeng Ma
Keyword(s):  
Triticum Aestivum ◽  
T Cells ◽  
Cell Death ◽  
Cell Lines ◽  
Nude Mice ◽  
Mechanism Of Action ◽  
Wheat Germ ◽  
The United States

Abstract Abstract 2857 Background: Non-Hodgkin's lymphoma (NHL) affects over 400,000 people in the United States and its incidence increases with age. Treatment options include cytotoxic chemotherapy, which is often poorly tolerated by elderly patients, and monoclonal antibody (mAb) therapy. Nearly 70% of NHL patients eventually die of the disease. Development of effective alternate treatments with favorable toxicity profiles is necessary. Fermented wheat germ extract (FWGE) has shown anticancer potential in laboratory animals as well as in some small clinical studies; it is produced under GMP conditions in Europe and sold as Avemar™. The mechanism of action of FWGE is unclear, but is thought to involve metabolic pathways involved in tumor cell death. We examined the effects of FWGE on NHL and found significant lymphomacidal activity using in vitro and in vivo assays. We then further purified and characterized the active components of FWGE in order to develop a more potent form and to understand the mechanism of action, physiologic, and immunologic properties. Methods: FWGE was produced by fermenting purified wheat germ (Triticum aestivum) with Baker's yeast. The FWGE was further purified by removing insoluble material, precipitating proteins, freeze drying, fractionating with Sepharose and Sephadex columns, and then dialyzing to remove small molecules. The resultant fermented wheat germ proteins (FWGP) were assessed for in vitro cytotoxicity and pro-apoptotic activity using a panel of NHL cell lines. In vivo lymphomacidal activity was assessed in nude mice bearing Raji lymphoma xenografts. Mice were treated with increasing daily doses of FWGE by gastric lavage and compared to untreated controls as well as the commercially available fermented wheat germ product, Avemar. Results: In vitro killing assays with FWGE (regardless of the source) demonstrated lymphomacidal properties in three NHL cell lines (Jurkat, Raji, and Ramos). Pre-treatment of FWGE with heat or proteinase K reduced the lymphomacidal activity, suggesting that the active component was a protein. Nude mice bearing Raji lymphoma xenografts treated with FWGE confirmed the lymphomacidal properties of FGWE; there was no detectable toxicity as assessed by observation, mouse weight, or blood counts. The purified low molecular weight proteins (FWGP) also demonstrated lymphomacidal properties by cytotoxicity assays and murine NHL models, but at 1/1000th of the original dose. When FWGP was combined with rituximab, there was enhanced in vitro lymphomacidal activity, with over a 4000-fold reduction in the IC50. FWGP-induced NHL cell death was mediated by caspase-3-dependent apoptosis. FWGP augmented the host immune effector mechanisms, including ADCC and CDC, along with potent activation of NK-T cells (CD3/69/16), CD4+ T-cells and monocytes. Conclusions: FWGE can be easily produced and has cytotoxic effects in in vitro assays and in vivo. The purified FWGP are quantifiable, and are 10–1000 times more potent than FWGE. The mechanism of FWGP activity is based on direct pro-apoptotic effects as well as augmentation of host immune mediators. FWGP has activity against various subtypes of NHL. Studies are ongoing to further characterize the immune effects and anti-cancer properties of FWGP, as is planning for a human clinical trial +/− rituximab in patients with NHL. Disclosure: No relevant conflicts of interest to declare.

Intracellular NAD+ Depletion Enhances Bortezomib-Induced Myeloma Cytotoxicity

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 330-330
Author(s):  
Antonia Cagnetta ◽  
Michele Cea ◽  
Chirag Acharya ◽  
Teresa Calimeri ◽  
Yu-Tzu Tai ◽  
...  
Keyword(s):  
Cell Death ◽  
Synergistic Effect ◽  
Cell Lines ◽  
Caspase 3 ◽  
Statistical Significance ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Nicotinamide Phosphoribosyltransferase

Abstract Abstract 330 Background: Our previous study demonstrated that inhibition of nicotinamide phosphoribosyltransferase (Nampt) acts by severely depleting intracellular NAD+ content and thus eliciting mitochondrial dysfunction and autophagic MM cell death. The proteasome inhibitor Bortezomib induces anti-MM activity by affecting a variety of signaling pathways. However, as with other agents, dose-limiting toxicities and the development of resistance limit its long-term utility. Here, we demonstrate that combining Nampt inhibitor and bortezomb induces synergistic anti-MM cell death both in vitro using MM cell lines or patient CD138+ MM cells and in vivo in a human plasmacytoma xenograft mouse model. Material and Methods: We utilized MM.1S, MM.1R, RPMI-8226, and U266 human MM cell lines, as well as purified tumor cells from patients relapsing after prior therapies. Cell viability and apoptosis assays were performed using Annexin V/PI staining. Intracellular NAD+ level and proteasome activity were quantified after 12, 24, and 48h exposure to single/combination drugs by specific assays. In vitro angiogenesis was assessed by Matrigel capillary-like tube structure formation assay. Immunoblot analysis was performed using antibodies to caspase-8, caspase-9, caspase-3, PARP, Bcl-2, and tubulin. CB-17 SCID male mice (n = 28; 7 mice/EA group) were subcutaneously inoculated with 5.0 × 106 MM.1S cells in 100 microliters of serum free RPMI-1640 medium. When tumors were measurable (3 weeks after MM cell injection), mice were treated for three weeks with vehicle alone, FK866 (30mg/kg 4 days weekly), Bortezomib (0.5 mg/kg twice weekly), or FK866 (30 mg/kg) plus Bortezomib (0.5 mg/kg). Statistical significance of differences observed in FK866, Bortezomib or combination-treated mice was determined using a Student t test. Isobologram analysis was performed using “CalcuSyn” software program. A combination index < 1.0 indicates synergism. Results/Discussion: Combining FK866 and Bortezomib induces synergistic anti-MM activity in vitro against MM cell lines (P<0.005, CI < 1) or patient CD138-positive MM cells (P< 0.004). FK866 plus Bortezomib-induced synergistic effect is associated with: 1)activation of caspase-8, caspase-9, caspase-3, and PARP; 2) improved intracellular NAD+ dissipation; 3) suppression of chymotrypsin-like, caspase-like, and trypsin-like proteolytic activities; 4) inhibition of NF-kappa B signaling; and 5) inhibition of angiogenesis. Importantly, the ectopic overexpression of Nampt rescues this observed synergistic effect; conversely, Nampt knockdown by RNAi significantly enhances the anti-MM effect of bortezomib. In the murine xenograft MM model, low dose combination FK866 (30 mg/kg) and Bortezomib (0.5 mg/kg) is well tolerated, significantly inhibits tumor growth (P < 0.001), and prolongs host survival (2–2.5 months in mice receiving combined drugs, P = 0.001). These findings demonstrate that intracellular NAD+ levels represent a major determinant in the ability of bortezomib to induce apoptosis of MM cells, providing the rationale for clinical protocols evaluating FK866 together with Bortezomib to improve patient outcome in MM. Disclosures: Munshi: Celgene: Consultancy; Millenium: Consultancy; Merck: Consultancy; Onyx: Consultancy.

scholarly journals Combining the IAP Antagonist Tolinapant with a DNA Hypomethylating Agent Enhances Immunogenic Cell Death in Preclinical Models of T-Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3986-3986
Author(s):  
George A. Ward ◽  
Simone Jueliger ◽  
Martin Sims ◽  
Matthew Davis ◽  
Adam Boxall ◽  
...  
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Cell Lines ◽  
Western Blotting ◽  
Inflammatory Mediators ◽  
Cell Lymphoma ◽  
T Cell Lymphoma ◽  
Immunogenic Cell Death

Abstract Introduction: Tolinapant is a potent, non-peptidomimetic antagonist of cIAP1, cIAP2 and XIAP. In ongoing Phase 2 trial (NCT02503423), tolinapant has shown activity against highly pre-treated peripheral and cutaneous T-cell lymphoma (Samaniego et al., Hematological Oncology, 2019). Hypomethylating agents (HMAs) have also shown clinical responses in some subsets of PTCL (Lemonnier et al., Blood, 2019). Both HMAs and IAP antagonists show immunomodulatory anti-cancer potential in pre-clinical studies. A Phase 1 clinical study investigating the combination of tolinapant and ASTX727 (oral decitabine) in AML is currently in progress (NCT04155580). Here we have undertaken a biomarker-driven approach to understand the potential for induction of immunogenic forms of cell death (ICD), such as necroptosis, by rational combination of our clinical compounds in pre-clinical models of T-cell lymphoma (TCL). Methods: On-target effects of decitabine and tolinapant were measured by analysing levels of DNMT1 and cIAP1, respectively, by Western blotting in mouse and human cell lines. Levels of key apoptosis, necroptosis or pyroptosis biomarkers were also monitored by Western blotting to provide evidence of lytic cell death contributing to a potential immune response. RIPK3- or MLKL-knockout cell lines were generated by CRISPR to demonstrate involvement of necroptosis in drug-induced cell death in a T-cell lymphoma cell line (BW5147.G.1.4) in vitro. Cell death was monitored by viability (CellTiterGlo) or real-time microscopy (IncuCyte) assays. Levels of key inflammatory mediators or DAMPS were measured in tissue culture supernatants and mouse plasma by Luminex assay (Ampersand). Results: Combined treatment of tolinapant and decitabine led to depletion of cIAP1 and DNMT1 in TCL cell lines, demonstrating on-target activity of tolinapant and decitabine, respectively. The combination of tolinapant and decitabine acted synergistically in mouse and human T-cell lymphoma cell lines to reduce viability in proliferation assays. Necroptosis was induced by decitabine or tolinapant alone in mouse TCL cell lines with robust activation of the RIPK1/RIPK3/MLKL necroptosis pathway when caspase activity was inhibited, and the combination of both agents enhanced loss of viability. Furthermore, we demonstrated decitabine treatment led to re-expression of both RIPK3 and MLKL in mouse cell lines, supporting published evidence that methylation can silence these key biomarkers (Koo et al., Cell Research, 2015; Koch et al., Neoplasia, 2021). Enhanced release of chemokine, cytokine and DAMPs was demonstrated with the combination of agents in vitro and in vivo. By removal of key necroptosis pathway components using CRISPR, we confirmed the importance of this lytic cell death pathway by demonstrating that RIPK3 -/- and MLKL -/- T-cell lymphoma (BW5147.G.1.4) cell lines had reduced necroptosis potential after treatment with tolinapant or decitabine alone or in combination; and demonstrate reduced release of inflammatory mediators in vitro. Finally, our in vivo evaluation of the combination of agents in mouse syngeneic models suggested that increased anti-tumour activity and immune-potentiating systemic biomarker modulation can be achieved with a tolerated dosing regimen of both compounds. Conclusion: These data demonstrate that decitabine enhances immunogenic cell death induced by tolinapant through the re-expression of genes in the necroptotic pathway. This finding provides strong rationale to explore this combination clinically. Disclosures Sims: Astex Pharmaceuticals: Current Employment. Davis: Astex Pharmacueticals: Current Employment. Smyth: Astex Pharmaceuticals: Current Employment.

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