scholarly journals Intratumoral Administration of a Novel Cytotoxic Formulation with Strong Tissue Dispersive Properties Regresses Tumor Growth and Elicits Systemic Adaptive Immunity in In Vivo Models

2020 ◽  
Vol 21 (12) ◽  
pp. 4493
Author(s):  
Lewis H. Bender ◽  
Franco Abbate ◽  
Ian B. Walters
Keyword(s):  
Tumor Growth ◽  
Adaptive Immunity ◽  
Tumor Regression ◽  
Checkpoint Inhibitors ◽  
Local Treatment ◽  
Cytotoxic Agents ◽  
Tumor Growth Inhibition ◽  
In Vivo Models ◽  
Drug Dispersion

The recent development of immune-based therapies has improved the outcome for cancer patients; however, adjuvant therapies remain an important line of treatment for several cancer types. To maximize efficacy, checkpoint inhibitors are often combined with cytotoxic agents. While this approach often leads to increased tumor regression, higher off target toxicity often results in certain patients. This report describes a novel formulation comprising a unique amphiphilic molecule, 8-((2-hydroxybenzoyl)amino)octanoate (SHAO), that non-covalently interacts with payloads to increase drug dispersion and diffusion when dosed intratumorally (IT) into solid tumors. SHAO is co-formulated with cisplatin and vinblastine (referred to as INT230-6). IT dosing of the novel formulation achieved greater tumor growth inhibition and improved survival in in vivo tumor models compared to the same drugs without enhancer given intravenously or IT. INT230-6 treatment increased immune infiltrating cells in injected tumors with 10% to 20% of the animals having complete responses and developing systemic immunity to the cancer. INT230-6 was also shown to be synergistic with programmed cell death protein 1 (PD-1) antibodies at improving survival and increasing complete responses. INT230-6 induced significant tumor necrosis potentially releasing antigens to induce the systemic immune-based anti-cancer attack. This research demonstrates a novel, local treatment approach for cancer that minimizes systemic toxicity while stimulating adaptive immunity.

Evaluation of the multi-kinase inhibitor regorafenib in the Pediatric Preclinical Testing Consortium osteosarcoma, rhabdomyosarcoma, and Ewing sarcoma in vivo models.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 10038-10038
Author(s):  
Douglas James Harrison ◽  
Jonathan Benjamin Gill ◽  
Michael Roth ◽  
Wendong Zhang ◽  
Beverly Teicher ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Ewing Sarcoma ◽  
Kinase Inhibitor ◽  
Objective Response ◽  
Primary Treatment ◽  
Tumor Growth Inhibition ◽  
Oral Gavage ◽  
Preclinical Testing ◽  
In Vivo Models

10038 Background: Regorafenib is a multi-kinase inhibitor, developed by adding a fluorine atom to the phenyl ring of sorafenib. Regorafenib inhibits multiple kinases including BRAF, FGFR1, KIT, PDGFRB, RAF, RET, and VEGFR1-3, many at a higher potency than sorafenib. Prior studies within the Pediatric Preclinical Testing Consortium (PPTC) demonstrated sorafenib exhibited intermediate activity for tumor growth inhibition in more than 50% of the sarcoma models tested at a dose of 60mg/kg by oral gavage daily (5 days/wk for 6 consecutive weeks). The in vivo effects of regorafenib were studied in the PPTC osteosarcoma (OS), rhabdomyosarcoma (Rh) and Ewing (EW) sarcoma xenograft models. Methods: The in vivo anticancer effects of regorafenib were assessed in a panel of 6 osteosarcoma models (OS2, OS9, OS31, OS33, OS36, OS60), two rhabdomyosarcoma models (Rh30, Rh41), and one Ewing sarcoma model (EW5). Regorafenib was administered by oral gavage at a dose of 30 mg/kg/day given daily for 21 consecutive days. Time to event and tumor volume responses were defined and analyzed utilizing standard PPTC statistical methods. Results: Regorafenib induced significant improvements in event-free survival (EFS) compared to control in 100% (9/9) of sarcoma models tested. Most models showed pronounced slowing of tumor growth compared to control during the 21 days of regorafenib treatment, with tumor growth generally approximating control rates soon after completion of regorafenib treatment. Three out of 8 sarcoma models demonstrated EFS T/C values > 2 (1/6 OS, 2/2 Rh, 0/1 EW). Minimum relative tumor volumes ranged from 0.74 to 1.60, with no models meeting criteria for objective response. Conclusions: Regorafenib induced modest inhibition of tumor growth in the PPTC sarcoma models evaluated. The overall pattern of response to the multi-kinase inhibitor regorafenib against the PPTC sarcoma models appears similar to that of the kinase inhibitor sorafenib, with pronounced slowing of tumor growth in some models that is limited to the period of agent administration being the primary treatment effect.

Combination of TLR9 agonist lefitolimod/MGN1703 with checkpoint inhibitors for cancer immunotherapy.

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 634-634 ◽  
Author(s):  
Manuel Schmidt ◽  
Kerstin Kapp ◽  
Barbara Volz ◽  
Detlef Oswald ◽  
Burghardt Wittig
Keyword(s):  
Tumor Growth ◽  
Colon Carcinoma ◽  
Checkpoint Inhibitors ◽  
Immune Surveillance ◽  
Phase Iii ◽  
Tumor Growth Inhibition ◽  
Tumor Models ◽  
Pilot Studies ◽  
Murine Tumor

634 Background: TLR9 agonists are potent activators of the immune system via induction of cellular and humoral responses. Preclinical and ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. Lefitolimod/MGN1703 is a covalently-closed dumbbell-like immune surveillance reactivator (ISR) with a broad immunomodulatory potential. After promising data from a phase II trial (IMPACT) as maintenance therapy after first-line induction chemotherapy in patients with metastatic colorectal cancer lefitolimod is recently evaluated in a phase III trial in mCRC patients (IMPALA). Methods: It was previously shown that lefitolimod can reduce tumor growth in several murine tumor models. Since the mode-of-action of lefitolimod starts upstream of the initiation points of checkpoint inhibitors aCTLA-4 or aPD-1/aPD-L1 a combinatory approach may result in an enhanced anti-tumor effect. Therefore, we employed two syngeneic murine tumor models: One with s.c. inoculation of CT26 cells and another with s.c. A20 cell challenge. Multiple doses of lefitolimod were injected s.c. or i.tu. Results: In the colon carcinoma CT26 model i.p. injection of aPD-L1 had no effect on the tumor growth, whereas peritumoral injection of lefitolimod led to a slowed tumor growth. The tumor growth was further inhibited by the combination (tumor growth inhibition, TGI - aPD-L1: no, lefitolimod: 28%, combination: 48%) resulting in prolonged survival of the mice. This combinatory effect was even more pronounced in the lymphoma A20 model: Injections of anti-PD-1 (i.p.) or lefitolimod (i.tu.) alone had a moderate anti-tumor effect which was vastly increased by the combination (TGI - aPD-1: 46%, lefitolimod: 50%, combination: 99%). Conclusions: In conclusion, we showed that lefitolimod, a member of dSLIM family of TLR9 agonists and an ISR, can enhance the limited anti-tumor effects of checkpoint inhibitors in pilot studies in murine colon carcinoma and lymphoma tumor models in vivo. These data show the promising potential for the combination with checkpoint inhibitors. In fact, a clinical trial in cooperation with MD Anderson evaluating the benefit of lefitolimod in combination with ipilimumab is currently ongoing.

Targeting Corticotroph HDAC and PI3-Kinase in Cushing Disease

2020 ◽  
Vol 106 (1) ◽  
pp. e232-e246 ◽  
Author(s):  
Dongyun Zhang ◽  
Robert Damoiseaux ◽  
Lilit Babayan ◽  
Everett Kanediel Rivera-Meza ◽  
Yingying Yang ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Symptom Relief ◽  
Academic Medical Center ◽  
Xenograft Model ◽  
Tumor Growth Inhibition ◽  
Transcriptional Level ◽  
Acth Secretion ◽  
Cushing Disease ◽  
In Vivo Models

Abstract Context Cushing disease (CD) is a life-threatening disorder. Therapeutic goals include symptom relief, biochemical control, and tumor growth inhibition. Current medical therapies for CD by and large exert no action on tumor growth. Objective To identify drugs that inhibit corticotroph tumor adrenocorticotropic hormone (ACTH) secretion and growth. Design High throughput screen employing a novel “gain of signal” ACTH AlphaLISA assay. Setting Academic medical center. Patients Corticotroph tumor tissues from patients with CD. Interventions None. Main outcome measures Potent inhibitors of corticotroph tumor ACTH secretion and growth. Results From a kinase inhibitor library, we identified the dual PI3K/HDAC inhibitor CUDC-907 as a potent inhibitor of murine and human corticotroph tumor ACTH secretion (median effective concentration 1-5 nM), and cell proliferation (median inhibitory concentration 5 nM). In an in vivo murine corticotroph tumor xenograft model, orally administered CUDC-907 (300 mg/kg) reduced corticotroph tumor volume (TV [cm3], control 0.17 ± 0.05 vs CUDC-907 0.07 ± 0.02, P < .05) by 65% and suppressed plasma ACTH (ACTH [pg/mL] control 206 ± 27 vs CUDC-907 47 ± 7, P < .05) and corticosterone (corticosterone [ng/mL] control 180 ± 87 vs CUDC-907 27 ± 5, P < .05) levels by 77% and 85% respectively compared with controls. We also demonstrated that CUDC-907 acts through HDAC1/2 inhibition at the proopiomelanocortin transcriptional level combined with its PI3K-mediated inhibition of corticotroph cell viability to reduce ACTH secretion. Conclusions Given its potent efficacy in in vitro and in vivo models of CD, combined with proven safety and tolerance in clinical trials, we propose CUDC-907 may be a promising therapy for CD.

The Bcl-2 Family Inhibitor ABT-263 Shows Significant Anti-Tumor Efficacy in Models of B Cell Non-Hodgkin’s Lymphoma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 825-825
Author(s):  
Alex R. Shoemaker ◽  
Michael J. Mitten ◽  
Anatol Oleksijew ◽  
Jacqeuline M. O’Connor ◽  
Baole Wang ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Growth Inhibition ◽  
B Cell ◽  
Cell Lymphoma ◽  
Cytotoxic Agents ◽  
Tumor Growth Inhibition ◽  
Complete Regression ◽  
Mantle Cell

Abstract ABT-263 is an orally bioavailable small molecule inhibitor of Bcl-2 family proteins with a Ki of ≤ 1 nM against Bcl-2, Bcl-XL, and Bcl-w. Non-Hodgkin’s B-cell lymphomas represent clinically relevant disease targets for this molecule due, in part, to strong expression of Bcl-2 often associated with various types of NHL (frequently involving a t(14;18) translocation including the Bcl-2 locus). ABT-263 exhibits sub-micromolar in vitro activity against a variety of NHL cell lines. DoHH-2 and WSU-DLCL2 are two B-cell NHL lines harboring the t(14;18) translocation that exhibit differential in vitro sensitivity to ABT-263. Granta-519 is a mantle cell lymphoma line with the characteristic t(11;14)(q13:q32) translocation resulting in overexpression of cyclin D1. ABT-263 has an EC50 of approximately 150 nM in the Granta-519 cell line. Here we present efficacy data evaluating the activity of ABT-263 in several NHL xenograft models. ABT-263 has significant in vivo anti-tumor efficacy in established flank tumor models both as monotherapy and in combination with cytotoxic agents. The efficacy of ABT-263 at 100 mg/kg/day, p.o., q.d. ×21 was evaluated as monotherapy and in combination with etoposide, vincristine, modified CHOP, R-CHOP, bortezomib, rapamycin, and rituximab. Results show that ABT-263 significantly inhibits tumor growth as a monotherapy (~50–60% tumor growth inhibition) and enhances the efficacy of these cytotoxic agents in combination therapy. Statistically significant enhancement of tumor growth inhibition was observed for each combination relative to monotherapy treatment. Efficacy was maintained even when therapy was initiated on larger (~500 mm3) tumors. Combinations of ABT-263 + rapamycin and ABT-263 + rituximab result in complete regression of a significant percentage of established B cell lymphoma tumors for a sustained period of time in vivo. The combination of ABT-263 + R-CHOP resulted in complete regression of 100% of the tumors in the mantle cell lymphoma model. The strong in vitro potency and tumor regressions seen in vivo suggest that ABT-263 has great potential for the oral treatment of NHL B-cell lymphomas.

scholarly journals Nanoparticle-complexed antimiRs for inhibiting tumor growth and metastasis in prostate carcinoma and melanoma

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Manfred Kunz ◽  
Madeleine Brandl ◽  
Animesh Bhattacharya ◽  
Lars Nobereit-Siegel ◽  
Alexander Ewe ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Prostate Carcinoma ◽  
Target Genes ◽  
Tumor Therapy ◽  
3D Models ◽  
Tumor Growth Inhibition ◽  
Melanoma Metastasis ◽  
In Vivo Models

Abstract Background MiRNAs act as negative regulators of gene expression through target mRNA degradation or inhibition of its translation. In cancer, several miRNAs are upregulated and play crucial roles in tumorigenesis, making the inhibition of these oncomiRs an interesting therapeutic approach. This can be achieved by directly complementary single-stranded anti-miRNA oligonucleotides (antimiRs). A major bottleneck in antimiR therapy, however, is their efficient delivery. The nanoparticle formation with polyethylenimine (PEI) may be particularly promising, based on the PEI’s ability to electrostatically interact with oligonucleotides. This leads to their protection and supports delivery. In the present study, we explore for the first time PEI for antimiR formulation and delivery. We use the branched low molecular weight PEI F25-LMW for the complexation of different antimiRs, and analyse tumor- and metastasis-inhibitory effects of PEI/antimiR complexes in different tumor models. Results In prostate carcinoma, transfection of antimiRs against miR-375 and miR-141 leads to tumor cell inhibition in 2D- and 3D-models. More importantly, an in vivo tumor therapy study in prostate carcinoma xenografts reveals anti-tumor effects of the PEI/antimiR complexes. In advanced melanoma and metastasis, we identify by a microRNA screen miR-150 as a particularly relevant oncomiR candidate, and validate this result in vitro and in vivo. Again, the systemic application of PEI/antimiR complexes inhibiting this miRNA, or the previously described antimiR-638, leads to profound tumor growth inhibition. These effects are associated with the upregulation of direct miRNA target genes. In a melanoma metastasis mouse model, anti-metastatic effects of PEI/antimiR treatment are observed as well. Conclusions We thus describe PEI-based complexes as efficient platform for antimiR therapy, as determined in two different tumor entities using in vivo models of tumor growth or metastasis. Our study also highlights the therapeutic relevance of miR-375, miR-141, miR-150 and miR-638 as target miRNAs for antimiR-mediated inhibition.

scholarly journals Δ40p53 isoform up-regulates netrin-1/UNC5B expression and potentiates netrin-1 pro-oncogenic activity

2021 ◽  
Vol 118 (36) ◽  
pp. e2103319118
Author(s):  
Yan Sun ◽  
Ambroise Manceau ◽  
Lisa Frydman ◽  
Lucie Cappuccio ◽  
David Neves ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Cancer Progression ◽  
Full Length ◽  
Tumor Growth Inhibition ◽  
In Vivo Models ◽  
Dependence Receptors ◽  
Transcription Factor P53

Netrin-1, a secreted protein recently characterized as a relevant cancer therapeutic target, is the antiapoptotic ligand of the dependence receptors deleted in colorectal carcinoma and members of the UNC5H family. Netrin-1 is overexpressed in several aggressive cancers where it promotes cancer progression by inhibiting cell death induced by its receptors. Interference of its binding to its receptors has been shown, through the development of a monoclonal neutralizing antinetrin-1 antibody (currently in phase II of clinical trial), to actively induce apoptosis and tumor growth inhibition. The transcription factor p53 was shown to positively regulate netrin-1 gene expression. We show here that netrin-1 could be a target gene of the N-terminal p53 isoform Δ40p53, independent of full-length p53 activity. Using stable cell lines, harboring wild-type or null-p53, in which Δ40p53 expression could be finely tuned, we prove that Δ40p53 binds to and activates the netrin-1 promoter. In addition, we show that forcing immortalized human skeletal myoblasts to produce the Δ40p53 isoform, instead of full-length p53, leads to the up-regulation of netrin-1 and its receptor UNC5B and promotes cell survival. Indeed, we demonstrate that netrin-1 interference, in the presence of Δ40p53, triggers apoptosis in cancer and primary cells, leading to tumor growth inhibition in preclinical in vivo models. Finally, we show a positive correlation between netrin-1 and Δ40p53 gene expression in human melanoma and colorectal cancer biopsies. Hence, we propose that inhibition of netrin-1 binding to its receptors should be a promising therapeutic strategy in human tumors expressing high levels of Δ40p53.

TLR9 agonist lefitolimod to improve antitumor effect of checkpoint inhibitors in vivo.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e14625-e14625 ◽  
Author(s):  
Manuel Schmidt ◽  
Kerstin Kapp ◽  
Barbara Volz ◽  
Detlef Oswald ◽  
Burghardt Wittig
Keyword(s):  
Tumor Growth ◽  
Colon Carcinoma ◽  
Checkpoint Inhibitors ◽  
Phase 1 ◽  
Tumor Growth Inhibition ◽  
Phase 2 ◽  
Tumor Models ◽  
Pilot Studies ◽  
Phase 2 Trial

e14625 Background: TLR9 agonists are potent activators of the immune system via induction of cellular and humoral responses. Preclinical and ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. Lefitolimod/MGN1703 is a covalently-closed dumbbell-like immune surveillance reactivator (ISR) with a broad immunomodulatory potential. Due to promising data from a phase 2 trial (IMPACT) as maintenance therapy after first-line chemotherapy in mCRC patients lefitolimod is recently evaluated in a phase 3 trial in mCRC patients (IMPALA). Furthermore, lefitolimod is currently investigated in a phase 2 trial in SCLC patients (IMPULSE) and in a phase 1 / 2 trial in HIV patients (TEACH). Methods: It was shown that lefitolimod reduces tumor growth in several murine tumor models. Since the mode-of-action of lefitolimod starts upstream of the initiation points of checkpoint inhibitors like anti-CTLA-4 or anti-PD-1/anti-PD-L1 a combinatory approach may result in an enhanced anti-tumor effect. Therefore, two syngeneic murine models were used – a colon carcinoma CT26 and a lymphoma A20 model – for evaluation of the anti-tumor effect in vivo. Results: In the CT26 model treatment with anti-PD-L1 (i.p.) had no effect on the tumor growth, whereas addition of lefitolimod (s.c.) to anti-PD-L1 led to an anti-tumor effect (tumor growth inhibition, TGI 48%) which consequently resulted in prolonged survival of the mice. This combinatory effect was even more pronounced in the A20 model where treatment with anti-PD-1 (i.p.) alone had a moderate anti-tumor effect which was vastly increased by the combination (TGI – anti-PD-1: 46%, anti-PD-1/lefitolimod 99%). Conclusions: In conclusion, we showed that lefitolimod, a member of dSLIM® family of TLR9 agonists and an ISR, can enhance the limited anti-tumor effects of checkpoint inhibitors in pilot studies in murine colon carcinoma and lymphoma tumor models in vivo. These data show the promising potential for the combination with checkpoint inhibitors. Notably, a clinical trial in cooperation with MD Anderson evaluating the benefit of lefitolimod in combination with ipilimumab is currently ongoing.

Melatonin modifies tumor hypoxia and metabolism by inhibiting HIF-1α and energy metabolic pathway in the in vitro and in vivo models of breast cancer

2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Glucose Metabolism ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Carbonic Anhydrases ◽  
In Vivo Models ◽  
Ca Ix ◽  
Gene And Protein Expression

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 

245 Human TLR8 knock-in mice potentiate immunotherapy responses of MC38 syngeneic tumors

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A264-A264
Author(s):  
Shanshan Qi ◽  
Hongjuan Zhang ◽  
Ruilin Sun ◽  
Annie An ◽  
Henry Li ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Growth ◽  
Cancer Immunotherapy ◽  
Tumor Regression ◽  
Tumor Growth Rate ◽  
Tumor Growth Inhibition ◽  
List Type ◽  
Rna Recognition ◽  
Ethical Guidelines ◽  
Ifn Γ

BackgroundToll-like receptors (TLRs) serve critical roles in mediating innate immune responses against many pathogens. However, they may also bind to endogenous ligands and lead to the pathogenesis of autoimmunity. Although TLR8 belongs to the same TLR family as TLR7, its role in inflammation and tumor progression is not yet fully understood due to the lack of suitable animal models. In humans, both TLR7 and TLR8 recognize single-stranded self-RNA, viral RNA, and synthetic small molecule agonists.1, 2 However, mouse Tlr8 is non-functional due to the absence of 5 amino acids necessary for RNA recognition. In order to create a mouse model with functional TLR8, we replaced exon 3 of mouse Tlr8 with human TLR8, therefore developing a hTLR8 knock-in (KI) model. Both heterozygous and homozygous hTLR8 KI mice are viable with inflammatory phenotypes, i.e. enlarged spleens and livers, and significantly higher IL-12 p40 levels under TLR8 agonist treatment. In this study, we evaluated the potential use of hTLR8 mice for cancer immunotherapy studies.MethodshTLR8 mice, together with naïve C57BL/6 mice, were inoculated with MC38 syngeneic tumor cells. Tumor bearing mice were grouped at a mean tumor volume of approximately 100 mm3 for treatment with PBS or 10 mg/kg anti-PD-1 (RMP1-14) antibody. At the efficacy endpoint, spleens and tumors were collected for flow cytometry profiling.ResultsAnti-PD-1 treatment of MC38 tumors in naïve C57BL/6 led to moderate tumor growth inhibition (TGI = 54%). Interestingly, anti-PD-1 treatment showed improved efficacy in hTLR8 mice (TGI = 79%), including 2/10 tumors with complete tumor regression. In comparison, non-treated MC38 tumor growth rate was slower in hTLR8 mice than in naïve mice. Anti-PD-1 treated hTLR8 mice also had significantly increased IFN-γ and TNF-a positive CD4+ T cells in the spleen, along with higher numbers of differentiated effector T cells. In addition, hTLR8 mice have activated dendritic cells and macrophages, acting as critical steps in initiation of the inflammatory process, with higher levels of pro-inflammatory cytokines, such as IL-6, IFN-γ, TNF-a, and IL-1β, which may promote Th1 priming and differentiation of T cells into IFN-γ or TNF-a producing cells.ConclusionshTLR8 mice offer a great tool to model cancer immunotherapy in an inflammatory/autoimmunity prone background. Moreover, hTLR8 mice can be effectively used to shift a ‘cold’ tumor phenotype to ‘hot’ tumors in a syngeneic setting.Ethics ApprovalAnimal experiments were conducted in accordance with animal welfare law, approved by local authorities, and in accordance with the ethical guidelines of CrownBio (Taicang).ReferencesKugelberg E. Making mice more human the TLR8 way. Nat Rev Immunol 2014;14:6.Guiducci C, Gong M, Cepika A-M, et al. RNA recognition by human TLR8 can lead to autoimmune inflammation. J Exp Med 2013;210:2903–2919.

scholarly journals BTK Inhibition Reverses MDSC-Mediated Immunosuppression and Enhances Response to Anti-PDL1 Therapy in Neuroblastoma

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 817
Author(s):  
Mehreen Ishfaq ◽  
Timothy Pham ◽  
Cooper Beaman ◽  
Pablo Tamayo ◽  
Alice L. Yu ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Growth ◽  
Checkpoint Inhibitors ◽  
No Production ◽  
Free Survival ◽  
T Cell Infiltration ◽  
Car T ◽  
Checkpoint Inhibitor Therapy

MDSCs are immune cells of myeloid lineage that plays a key role in promoting tumor growth. The expansion of MDSCs in tumor-bearing hosts reduces the efficacy of checkpoint inhibitors and CAR-T therapies, and hence strategies that deplete or block the recruitment of MDSCs have shown benefit in improving responses to immunotherapy in various cancers, including NB. Ibrutinib, an irreversible molecular inhibitor of BTK, has been widely studied in B cell malignancies, and recently, this drug is repurposed for the treatment of solid tumors. Herein we report that BTK is highly expressed in both granulocytic and monocytic murine MDSCs isolated from mice bearing NB tumors, and its increased expression correlates with a poor relapse-free survival probability of NB patients. Moreover, in vitro treatment of murine MDSCs with ibrutinib altered NO production, decreased mRNA expression of Ido, Arg, Tgfβ, and displayed defects in T-cell suppression. Consistent with these findings, in vivo inhibition of BTK with ibrutinib resulted in reduced MDSC-mediated immune suppression, increased CD8+ T cell infiltration, decreased tumor growth, and improved response to anti-PDL1 checkpoint inhibitor therapy in a murine model of NB. These results demonstrate that ibrutinib modulates immunosuppressive functions of MDSC and can be used either alone or in combination with immunotherapy for augmenting antitumor immune responses in NB.

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