Tumor Growth In Animal Models Research Articles

Biodegradable chitin nanofiber-alginate dialdehyde hydrogel: An injectable, self-healing scaffold for anti-tumor drug delivery

Injectable hydrogels fabricated from natural polymers have attracted increasing attentions for their potential in biomedical application owing to the biocompatibility and biodegradability. A new class of natural polymer based self-healing hydrogel is constructed through dynamic covalent bonds. The injectable self-healing hydrogels are fabricated by introducing alginate aldehyde to form Schiff base bonds with the chitin nanofibers. These hydrogels demonstrate excellent self-healing properties, injectability, and pH-responsive sol-gel transition behaviors. As a result, they can serve as carriers to allow an effective encapsulation of doxorubicin (DOX) for drug delivery. Furthermore, these hydrogels exhibit excellent biocompatibility and degradability in vitro and in vivo. The sustained release of DOX from the hydrogels effectively suppresses tumor growth in animal models without causing significant systemic toxicity, suggesting their potential application in anti-tumor therapies.

Poria acid inhibit the growth and metastasis of renal cell carcinoma by inhibiting the PI3K/akt/NF-κb signaling pathway

BackgroundPoria acid (PAC) is a triterpene compound found in Poria cocos, a traditional Chinese medicine (TCM). The current study aims to explore the therapeutic effects and potential mechanisms of PAC on the migration and proliferation of human renal cell carcinoma (RCC) cells as well as tumor growth in animal model. MethodsCell viability and proliferative capacity of normal renal cells and RCC cells were investigated by MTT assay. In addition, 786-O cells were divided into four groups and treated with different concentrations of PAC (0, 20, 40, and 60 μM) for 48 h. Cell scratch test and cell invasion assay were performed to evaluate the effects of PAC on the invasion and migration of RCC cells, respectively. The effects of PAC on apoptosis of RCC cells and expression levels of PI3K/Akt/NF-kB signaling pathway-related biomarkers were investigated using TUNEL staining and Western blotting methods, respectively. Effects of PAC on the inhibitory activity of RCC tumor in mice were evaluated in a 786-O CDX model. ResultsThe study found that PAC inhibited the viability of RCC cells in a dose-dependent manner, as demonstrated by in vitro cell assays (p < 0.05). However, PAC showed no significant inhibitory effect on normal renal cells (p > 0.05). PAC also significantly inhibited the migration and invasion of RCC via EMT/MMP signaling pathways (p < 0.05). Immunofluorescence and immunoblotting results showed that PAC induced the apoptosis of RCC, which was accompanied by changes in the expression levels of apoptosis-related proteins (p < 0.05). Moreover, PAC significantly downregulated the PI3K/Akt/NF-kB signaling pathway in a concentration-dependent manner (p < 0.05). The effect of PAC on RCC apoptosis was dramatically reversed by 740Y–P (PI3K agonist) (p < 0.05) but significantly enhanced in the presence of LY294002 (PI3K inhibitor) (p < 0.05). The results of in vivo experiment also demonstrated that the antitumor activity of PAC was achieved by affecting the PI3K/Akt/NF-kB signaling pathway. ConclusionsPAC can effectively suppress the proliferation, invasion and migration of RCC cells, and exhibit anti-tumor effects in RCC model by inhibiting the PI3K/Akt/NF-kB signaling pathway.

Semaphorin 3A causes immune suppression by inducing cytoskeletal paralysis in tumour-specific CD8+ T cells

Semaphorin-3A (SEMA3A) functions as a chemorepulsive signal during development and can affect T cells by altering their filamentous actin (F-actin) cytoskeleton. The exact extent of these effects on tumour-specific T cells are not completely understood. Here we demonstrate that Neuropilin-1 (NRP1) and Plexin-A1 and Plexin-A4 are upregulated on stimulated CD8+ T cells, allowing tumour-derived SEMA3A to inhibit T cell migration and assembly of the immunological synapse. Deletion of NRP1 in both CD4+ and CD8+ T cells enhance CD8+ T-cell infiltration into tumours and restricted tumour growth in animal models. Conversely, over-expression of SEMA3A inhibit CD8+ T-cell infiltration. We further show that SEMA3A affects CD8+ T cell F-actin, leading to inhibition of immune synapse formation and motility. Examining a clear cell renal cell carcinoma patient cohort, we find that SEMA3A expression is associated with reduced survival, and that T-cells appear trapped in SEMA3A rich regions. Our study establishes SEMA3A as an inhibitor of effector CD8+ T cell tumour infiltration, suggesting that blocking NRP1 could improve T cell function in tumours.

Intratumoral Biosynthesis of Gold Nanoclusters by Pancreatic Cancer to Overcome Delivery Barriers to Radiosensitization.

Nanoparticle delivery to solid tumors is a prime challenge in nanomedicine. Here, we approach this challenge through the lens of biogeochemistry, the field that studies the flow of chemical elements within ecosystems as manipulated by living cellular organisms and their environments. We leverage biogeochemistry concepts related to gold cycling against pancreatic cancer, considering mammalian organisms as drivers for gold nanoparticle biosynthesis. Sequestration of gold nanoparticles within tumors has been demonstrated as an effective strategy to enhance radiotherapy; however, the desmoplasia of pancreatic cancer impedes nanoparticle delivery. Our strategy overcomes this barrier by applying an atomic-scale agent, ionic gold, for intratumoral gold nanoparticle biosynthesis. Our comprehensive studies showed the cancer-specific synthesis of gold nanoparticles from externally delivered gold ions in vitro and in a murine pancreatic cancer model in vivo; a substantial colocalization of gold nanoparticles (GNPs) with cancer cell nuclei in vitro and in vivo; a strong radiosensitization effect by the intracellularly synthesized GNPs; a uniform distribution of in situ synthesized GNPs throughout the tumor volume; a nearly 40-day total suppression of tumor growth in animal models of pancreatic cancer treated with a combination of gold ions and radiation that was also associated with a significantly higher median survival versus radiation alone (235 vs 102 days, respectively).

Drug monomers from Salvia miltiorrhiza Bge. promoting tight junction protein expression for therapeutic effects on lung cancer

Salvia miltiorrhiza Bge. is a traditional Chinese medicine (TCM) that has been used for treatment of various diseases, including cancer by activating blood circulation and removing blood stasis. Tanshinone (TanIIA) and cryptotanshinone (CPT) are major lipophilic compounds extracted from the root of Salvia miltiorrhiza Bge., which are considered to be the effective compounds affecting the efficacy of the anti-tumor therapy of Salvia miltiorrhiza Bge. We have explored the mechanism of CPT and TanIIA exerting inhibition in non-small cell lung cancer (NSCLC) to provide experimental data support for guiding the translational development and clinical application of anti-tumor components of TCM. The subcutaneous tumor model and in vitro culture model of A549 cells was constructed to evaluate CPT and TanIIA's tumour-inhibitory effect respectively. RNA sequencing (RNA-seq) and bioinformatics analysis were conducted to identify differentially expressed genes (DEGs) and signalling pathways related to CPT and TanIIA treatment. qRT-PCR and Western blot were used to explore the mechanism of CPT and TanIIA intervention on NSCLC. Both CPT and TanIIA significantly inhibited the proliferation of A549 tumor cells and tumor growth in animal models. After intervention, the migration ability decreased and the level of apoptosis increased. RNA-seq results showed that both CPT and TanIIA could cause gene differential expression, miR-21-5p as one of the most significant gene expression differences between the two groups, and could act on cell connectivity. CPT and TanIIA play a regulatory role in regulating tight junction proteins (Occludin and ZO1), and Occludin mRNA and protein levels were reduced in an in vitro miR-21-5p overexpression A549 cell model. The mechanisms may be related to the reduction of miR-21-5p expression to increase the level of promoted tight junction protein expression for the purpose of inhibiting proliferation and invasion of NSCLC.

Inhibition of orthotopic castration-resistant prostate cancer growth and metastasis in mice by JC VLPs carrying a suicide gene driven by the PSA promoter.

Metastatic castration-resistant prostate cancer (mCRPC) is challenging to treat. Virus-like particles (VLPs), originating from JC polyomavirus (JCPyV) and carrying a suicide gene driven by the PSA promoter (PSAtk-VLPs), can inhibit tumor growth in animal models of human prostate cancer. However, the efficacy of suppression of orthotopic PCa growth and metastasis by PSAtk-VLPs remains undetermined. Here, we established an iRFP stable expression CRPC cell line suitable for deep-tissue observation using fluorescence molecular tomography (FMT). These cells were implanted into murine prostate tissue, and PSAtk-VLPs were systemically administered via the tail vein along with the prodrug ganciclovir (GCV), allowing for the real-time observation of orthotopic prostate tumor growth and CRPC tumor metastasis. Our findings demonstrated that systemic PSAtk-VLPs administration with GCV and subsequent FMT scanning facilitated real-time observation of the suppressed growth in mouse iRFP CRPC orthotopic tumors, which further revealed a notable metastasis rate reduction. Systemic PSAtk-VLPs and GCV administration effectively inhibited orthotopic prostate cancer growth and metastasis. These findings suggest the potential of JCPyV VLPs as a promising vector for mCRPC gene therapy. Conclusively, systemically administered JCPyV VLPs carrying a tissue-specific promoter, JCPyV VLPs can protect genes within the bloodstream to be specifically expressed in specific organs.

Hypomethylation of DRD2 promotes breast cancer through the FLNA-ERK pathway

We investigated the effect of stem cell marker dopamine receptor D2 (DRD2) on the proliferation of hormone-receptor-negative breast cancer cells. High-throughput DNA methylation sequencing on an 850 K chip was used to pre-screen breast cancer tissues with significant methylation differences. The expression of DRD2 in breast cancer and normal breast tissues, and clinical risk factors, were detected by pyrophosphoric acid validation and immunohistochemistry. In vitro and in vivo experiments verified the possible molecular signaling pathways. DRD2 promoter region was hypomethylated in hormone-receptor-negative breast cancer or with high-risk factors compared to the normal tissues. The proliferation of breast cancer cells was enhanced after DRD2 was upregulated and decreased after DRD2 was downregulated. In vivo experiments found that tumor growth and the expression of antigen KI-67 (Ki67) and the cluster of differentiation 31 (CD31) were improved by the overexpression of DRD2 and inhibited by the down expression of DRD2. In vivo and in vitro experiments demonstrated the phosphorylation of filamin A and extracellular signal-regulated kinase (FLNA-ERK) was influenced by the expression of DRD2, suggesting DRD2 plays a role in the FLNA-ERK signaling pathway. Methylation inhibitors (5-aza-2-deoxycytidine, 5-azadc) partially reversed the inhibitory effect of DRD2 down expression on cell proliferation, migration, and tumor growth in animal models, indicating that inhibition of DRD2 methylation promotes cancer development. This study demonstrated the DRD2 promoter region is hypomethylated in hormone-receptor-negative breast cancer or with high-risk factors. The methylation status of the DRD2 promoter and FLNA-ERK signaling pathway and the DRD2 expression in breast cancer treatment need to be considered.

Safety and efficacy of HB0025, an anti-PD-1/VEGF bispecific antibody fusion protein, in patients with advanced solid tumors: Preliminary results from an FIH trial.

2589 Background: HB0025 is a recombinant humanized anti-PD-L1 monoclonal antibody-VEGFR1 fusion Protein. Nonclinical data both in vitro and vivo have shown high-affinity binding to both targets as well as the inhibition of tumor growth in animal models. Here, we present preliminary safety and efficacy data from a dose escalation phase I study of HB0025. Methods: Eligible patients(pts) were ≥18 years old (ECOG PS 0–1) who had advanced solid tumors (NSCLC, gynecological tumors, digestive system tumors, etc.) and failed standard treatment. This phase 1 dose escalation includes accelerated titration (0.01, 0.03, 0.1 and 0.3mg/kg) and conventional 3+3 dose escalation (1.0, 3.0, 6.0, 10, 12, 20, and 30.0 mg/kg). HB0025 is administered intravenously every 14 days (Q2W). Objectives include evaluation of safety, pharmacokinetics (PK), pharmacodynamics (PD), immunogenicity, and antitumor activity. Adverse events (AEs) were reported with CTCAE v5.0 and DLTs were evaluated within a 28-day window. Results: As of Aug 30th 2022, 30 pts including 8 male and 22 female from Caucasian and Mongoloid have received HB0025 at doses of 0.01 mg/kg (n=1), 0.03 mg/kg (n=2), 0.1 mg/kg (n=1), 0.3 mg/kg (n=1),1.0 mg/kg (n=3), 3.0 mg/kg (n=7), 6.0mg/kg (n=7), 10.0 mg/kg (n=5), and 12.0mg/kg (n=3) Q2W. Overall, the median age was 55 years and the median lines of previous treatment was four. Of the 22 evaluable pts dosed at ≥ 3 mg/kg Q2W, the ORR was 9.1% (2/22) and the disease control rate (DCR) was 50% [11/22]. Among the 2 responders, a CR (colorectal ca) pt whose prior therapy was no immune checkpoint inhibitor (ICI) or bevacizumab have continued more than 36 weeks; and a PR (NSCLC) pt with duration more than 18 weeks whose tumor was 60.2% regression and prior ICI failure. Till the date of submission, the therapy was continuing for the CR and PR pts. Treatment-related adverse events (TRAEs) occurred in 83.3% of pts. The grade 3 TRAEs occurred in 20% [6/30] and treatment-related SAEs occurred in 13.3% [4/30]. One DLT occurred in the 12.0mg/kg cohort. No death occurred related to HB0025. TRAEs leading to treatment discontinuation occurred in 13.3% of pts [4/30]. The most frequent TRAEs were hypertriglyceridemia (23.3%), hypercholesterolemia (23.3%), anemia (16.7%), alanine aminotransferase increase (16.7%), and proteinuria (13.3%). Conclusions: HB0025 shows manageable safety and promising anti-tumor activity in pts with various solid tumors. To better characterize the risk-benefit profile, HB0025 is currently enrolled at 20.0 mg/kg Q2W and is being explored at doses 10 mg/kg in expansion cohorts. The future data, including PK, PD and ADA will be presented. Clinical trial information: NCT04678908 .

A review on the role of SNHG8 in human disorders.

Small nucleolar RNA host gene 8 (SNHG8) is a long non-coding RNA that has physiological roles in epithelial and muscle satellite cells. This lncRNA has been reported to be over-expressed in a variety of cancer cell lines. Its silencing has attenuated tumor growth in animal models of cancers. SNHG8 can be served as a molecular sponge for some miRNAs to regulate their target genes. miR-634/ZBTB20, miR-335-5p/PYGO2, miR588/ATG7, miR-152/c-MET, miR-1270/BACH1, miR-491/PDGFRA, miR-512-5p/TRIM28, miR-149-5p/PPM1F, miR-542-3p/CCND1/CDK6, miR-656-3p/SERBP1, miR-656-3p/SATB1, miR-1270/S100A11 and miR-384/HOXB7 are examples of molecular axes being regulated by SNHG8 in the context of cancer. Moreover, it can affect pathogenesis of atherosclerosis, chronic cerebral ischemia, acute gouty arthritis, ischemic stroke and myocardial infarction through modulation of a number of molecular axes such as SNHG8/miR-384/Hoxa13/FAM3A and miR-335/RASA1 as well as NF-κB signaling pathway. The current review aims at summarization of the role of SNHG8 in diverse human disorders.

Abstract 639: Prevention of pancreatitis and subsequent pancreatic cancer and fibrosis development by PI3Kγ inhibition

Abstract Anti-inflammatory, immunosuppressive macrophages play significant roles in promoting both tumorigenesis and fibrosis. Wound-healing type macrophages accumulate in sites of tissue injury, such as the cirrhotic liver, where they can induce oxidative damage and secrete immunosuppressive and pro-fibrotic factors that lead to oncogenesis. These innate immune cells are also major cellular producers of PDGFB and TGF-β1, which stimulate fibroblasts to secrete extracellular matrix proteins, such as collagen, and which also promote metastatic progression of neoplastic diseases. Chronic liver and pancreatic inflammation are significant risk factors for the development of hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC), respectively. We have determined that the myeloid cell specific PI3K isoform PI3Kγ promotes the accumulation of myeloid cells and their immune suppressive polarization within the tumor microenvironment (TME), and that this kinase thereby promotes tumor growth in animal models of cancer, including PDAC. Genetic and pharmacological inhibition of PI3Kγ suppresses tumor growth and reduces fibrosis that is associated with PDAC and other tumors. Targeting immune suppressive myeloid cells represent an emerging approach within the field of cancer immunotherapy and fibrosis treatment; indeed, inhibition of PI3Kγ by the therapeutic eganelisib has shown beneficial effects, including increased overall and progression-free survival in clinical trials for melanoma, head and neck carcinoma, urothelial carcinoma and triple negative breast carcinoma. In this project, we are exploringWe examined the effect of whether PI3Kγ inhibition can in cancer prevention using mouse models of prevent cancer development by suppressing damaging chronic hepatic and pancreatic inflammation, associated fibrosis, and progression towards tumorigenesis using models of HCC and PDAC. We found that PI3Kγ inhibition prevented prevents acute and chronic inflammation and that promotes normal tissue loss and development of fibrosis in mouse models of chronic pancreatitis and liver inflammation. Studies are underway to determine iOur studies indicate thatf PI3Kγ inhibition can also prevent the development of pancreatic and liver carcinoma that results fromin response to chronic inflammation and fibrosis. Our These studies thus far suggest the a potential role of for PI3Kγ inhibition in the prevention of cancer development by preventing the chronic inflammation that leads towards fibrosis and carcinogenesis. The results of these studies could be applied to the future design of clinical trials with using clinical PI3Kγ inhibitors. Citation Format: Anghesom Ghebremedhin, Judith Varner, Marc Paradise. Prevention of pancreatitis and subsequent pancreatic cancer and fibrosis development by PI3Kγ inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 639.

Systemic delivery of glycosylated-PEG-masked oncolytic virus enhances targeting of antitumor immuno-virotherapy and modulates T and NK cell infiltration.

Rationale: Immuno-virotherapy has emerged as a promising approach for cancer treatment, as it directly and cytotoxically eliminates tumors with systemic immune stimulation. However, the clinical efficacy of this approach remains limited by inappropriate delivery routes, robust antiviral responses, and the tumor immunosuppressive microenvironment. Methods: To address these challenges, we propose a surface engineering strategy that masks oncolytic herpes simplex virus (oHSV) with a galactose-polyethylene-glycol (PEG) polymer chain to minimize host antiviral responses and selectively targets tumors by limiting exposure to circulation upon systemic administration. We evaluated the antitumor efficacy of glycosylated-PEG-oHSV by examining tumor growth in animal models and analyzing tumor-infiltrating CD8+T cells and NK cells in the tumor microenvironment (TME). To assess the neutralizing antibody levels after systemic administration of glycosylated-PEG-oHSV, we utilized a mouse model and measured oHSV-specific IgG. Results: We demonstrate that the glycosylated-PEG modified oHSV does not affect the replication of oHSV yet exhibits high specificity to the asialoglycoprotein receptor (ASGPR) overexpressed in hepatocellular carcinoma cells. This results in selectively targeting cancer cells and deep penetration into tumors while avoiding spreading into the brain. Our approach also effectively reduces oHSV-specific neutralizing antibody levels to mitigate host antiviral immune response. Notably, our glycosylated-PEG-oHSV alleviates the immunosuppressive microenvironment within tumors by reducing regulatory T cells, augmenting the infiltration of activated CD8+T cells and NK cells with increasing release of anti-tumor cytokines, to impede tumor progression. Conclusion: Our findings offer a widely applicable and universal strategy to enhance cancer immuno-virotherapy through systemic administration of non-genetically engineered oncolytic viruses. This approach has the potential to overcome the limitations of current immune-virotherapy strategies and may improve clinical outcomes for cancer patients.

Circ_0075960 targets the miR-202-5p/CTNND1 axis to promote the growth and migration of endometrial carcinoma cells via regulating Wnt/β-catenin signaling activity.

Endometrial carcinoma (EC) is one of the most common malignant tumors of the female reproductive tract, involving multiple molecular alterations. Circular RNA (circRNA) dysregulation is frequently observed in EC tissues, suggesting the involvement of circRNA in EC development. We aimed to investigate the role of circ_0075960 in EC. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot assays were applied for expression analysis. CCK-8, EdU, colony formation, flow cytometry and wound healing assays were employed for functional analysis. The predicted binding relationship between miR-202-5p and circ_0075960 or CTNND1 was validated by dual-luciferase reporter experiment. In vivo animal models were constructed in nude mice to verify the role of circ_0075960 in tumor growth. Circ_0075960 and CTNND1 were upregulated, while miR-202-5p was downregulated in EC. Knockdown of circ_0075960 induced EC cell apoptosis, suppressed cell proliferation and migration, and repressed tumor growth in animal models. MiR-202-5p was targeted by circ_0075960 and it directly bound to CTNND1 3'UTR. The inhibition of circ_0075960 knockdown or miR-202-5p enrichment on EC cell proliferation and migration was reversed by miR-202-5p depletion or CTNND1 overexpression, respectively. Circ_0075960 targeted miR-202-5p to positively regulate CTNND1 expression. Moreover, circ_0075960 knockdown weakened the activity of Wnt/β-catenin signaling via targeting the miR-202-5p/CTNND1 axis. Circ_0075960 targets the miR-202-5p/CTNND1 axis to modulate Wnt/β-catenin signaling activity, thus contributing to the malignant development of EC.

Targeting CD89 on tumor-associated macrophages overcomes resistance to immune checkpoint blockade

BackgroundDespite the survival benefits observed with immune checkpoint blockade (ICB) treatment—programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1), many patients with cancer have not benefited from these agents because of impaired...

Regional healthy brain activity, glioma occurrence and symptomatology.

It is unclear why exactly gliomas show preferential occurrence in certain brain areas. Increased spiking activity around gliomas leads to faster tumour growth in animal models, while higher non-invasively measured brain activity is related to shorter survival in patients. However, it is unknown how regional intrinsic brain activity, as measured in healthy controls, relates to glioma occurrence. We first investigated whether gliomas occur more frequently in regions with intrinsically higher brain activity. Second, we explored whether intrinsic cortical activity at individual patients’ tumour locations relates to tumour and patient characteristics.Across three cross-sectional cohorts, 413 patients were included. Individual tumour masks were created. Intrinsic regional brain activity was assessed through resting-state magnetoencephalography acquired in healthy controls and source-localized to 210 cortical brain regions. Brain activity was operationalized as: (i) broadband power; and (ii) offset of the aperiodic component of the power spectrum, which both reflect neuronal spiking of the underlying neuronal population. We additionally assessed (iii) the slope of the aperiodic component of the power spectrum, which is thought to reflect the neuronal excitation/inhibition ratio. First, correlation coefficients were calculated between group-level regional glioma occurrence, as obtained by concatenating tumour masks across patients, and group-averaged regional intrinsic brain activity. Second, intrinsic brain activity at specific tumour locations was calculated by overlaying patients’ individual tumour masks with regional intrinsic brain activity of the controls and was associated with tumour and patient characteristics.As proposed, glioma preferentially occurred in brain regions characterized by higher intrinsic brain activity in controls as reflected by higher offset. Second, intrinsic brain activity at patients’ individual tumour locations differed according to glioma subtype and performance status: the most malignant isocitrate dehydrogenase-wild-type glioblastoma patients had the lowest excitation/inhibition ratio at their individual tumour locations as compared to isocitrate dehydrogenase-mutant, 1p/19q-codeleted glioma patients, while a lower excitation/inhibition ratio related to poorer Karnofsky Performance Status, particularly in codeleted glioma patients.In conclusion, gliomas more frequently occur in cortical brain regions with intrinsically higher activity levels, suggesting that more active regions are more vulnerable to glioma development. Moreover, indices of healthy, intrinsic excitation/inhibition ratio at patients’ individual tumour locations may capture both tumour biology and patients’ performance status. These findings contribute to our understanding of the complex and bidirectional relationship between normal brain functioning and glioma growth, which is at the core of the relatively new field of ‘cancer neuroscience’.

456MO METEOR-1: A phase I study of the safety and efficacy of the protein arginine methyltransferase 5 (PRMT5) inhibitor GSK3326595 in advanced solid tumors

PRMT5 methylates arginines in proteins important for tumor development. GSK3326595, a first-in-class selective PRMT5 inhibitor, suppressed tumor growth in animal models. METEOR-1 is a phase I, dose escalation/expansion, 3-part study in patients (pts) with relapsed/refractory solid tumors or non-Hodgkin lymphoma (NHL). Here we describe results from the part 2 dose expansion phase.

PET/MR Imaging of a Lung Metastasis Model of Clear Cell Renal Cell Carcinoma with (2S,4R)-4-[18F]Fluoroglutamine

PurposeMetabolic reprogramming plays an important role in the tumorigenesis of clear cell renal cell carcinoma (ccRCC). Currently, positron emission tomography (PET) reporters are not used clinically to visualize altered glutamine metabolism in ccRCC, which greatly hinders detection, staging, and real-time therapeutic assessment. We sought to determine if (2S,4R)-4-[18F]fluoroglutamine ([18F]FGln) could be used to interrogate altered glutamine metabolism in ccRCC lesions in the lung.ProceduresWe generated a novel ccRCC lung lesion model using the ccRCC cell line UMRC3 stably transfected with GFP and luciferase constructs. This cell line was used for characterization of [18F]FGln uptake and retention by transport analysis in cell culture and by PET/MRI (magnetic resonance imaging) in animal models. Tumor growth in animal models was monitored using bioluminescence (BLI) and MRI. After necropsy, UMRC3 tumor growth in lung tissue was verified by fluorescence imaging and histology.ResultsIn UMRC3 cells, [18F]FGln cell uptake was twofold higher than cell uptake in normal kidney HEK293 cells. Tracer cell uptake was reduced by 60–90% in the presence of excess glutamine in the media and by 20–50% upon treatment with V-9302, an inhibitor of the major glutamine transporter alanine-serine-cysteine transporter 2 (ASCT2). Furthermore, in UMRC3 cells, [18F]FGln cell uptake was reduced by siRNA knockdown of ASCT2 to levels obtained by the addition of excess exogenous glutamine. Conversely, [18F]FGln cellular uptake was increased in the presence of the glutaminase inhibitor CB-839. Using simultaneous PET/MRI for visualization, retention of [18F]FGln in vivo in ccRCC lung tumors was 1.5-fold greater than normal lung tissue and twofold greater than muscle. In ccRCC lung tumors, [18F]FGln retention did not change significantly upon treatment with CB-839.ConclusionsWe report one of the first direct orthotopic mouse models of ccRCC lung lesions. Using PET/MR imaging, lung tumors were easily discerned from normal tissue. Higher uptake of [18F]FGln was observed in a ccRCC cell line and lung lesions compared to HEK293 cells and normal lung tissue, respectively. [18F]FGln cell uptake was modulated by exogenous glutamine, V-9302, siRNA knockdown of ASCT2, and CB-839. Interestingly, in a pilot therapeutic study with CB-839, we observed no difference in treated tumors relative to untreated controls. This was in contrast with cellular studies, where CB-839 increased glutamine uptake.

CircAKT3 promotes cell proliferation, survival and glutamine metabolism of gastric cancer by activating SLC1A5 expression via targeting miR-515-5p.

Gastric cancer (GC) is a common disorder in the population. Numerous studies have reported that the pathogenesis of GC is implicated in the dysregulation of circular RNAs (circRNAs). The aim of this study was to investigate the role and functional mechanism of circ_0000199 (circAKT3) in GC. The expression of circAKT3, miR-515-5p and solute carrier family 1 member 5 (SLC1A5) mRNA was measured by quantitative real-time PCR (qPCR). Cell proliferation was assessed by cell counting kit-8 (CCK-8) assay, colony formation assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. Cell apoptosis was determined by flow cytometry assay and caspase 3/7 activity. The protein levels of glutaminase (GLS), proliferating cell nuclear antigen (PCNA) and cleaved-caspase3 were detected by western blot. The binding relationship between miR-515-5p and circAKT3 or SLC1A5 was verified by dual-luciferase reporter assay or RIP assay. The role of circAKT3 in vivo was investigated by establishing animal models. The abundance of Ki-67 and PCNA was detected by IHC assay. The expression of circAKT3 in GC tissues and cells was enhanced. The knockdown of circAKT3 inhibited GC cell proliferation, survival and glutamine metabolism, as well as tumor growth in animal models. MiR-515-5p was a target of circAKT3, and miR-515-5p suppressed the expression of SLC1A5 by binding to SLC1A5 3'UTR. CircAKT3 relieved the inhibition of miR-515-5p on SLC1A5 expression by targeting miR-515-5p. The effects of circAKT3 knockdown were reversed by miR-515-5p depletion, and the effects of miR-515-5p restoration were abolished by SLC1A5 overexpression. CircAKT3 promotes the malignant development of GC by activating SLC1A5 expression via targeting miR-515-5p.

Circ_KIAA1199 inhibits MSI1 degradation by targeting miR-34c-5p to drive the malignant cell behaviors and tumor growth of colorectal cancer.

Circular RNAs (circRNAs) are important regulators that drive or inhibit cancer initiation and development. Here, we identified the expression and function of a circRNA, circ_KIAA1199, in colorectal cancer (CRC). The expression levels of circ_KIAA1199, microRNA-34c-5p (miR-34c-5p) and Musashi RNA-binding protein 1 (MSI1) mRNA were detected by quantitative real-time PCR. Cell proliferative capacity was assessed by colony formation assay, EdU assay and MTT assay. Cell apoptosis was determined by flow cytometry assay. Cell migration and cell invasion were investigated by transwell assay. The expression of MSI1 protein and proliferation, migration-related markers was detected by western blot. The relationship between miR-34c-5p and circ_KIAA1199 or MSI1 was verified by dual-luciferase reporter assay. Animal models were constructed to ascertain the role of circ_KIAA1199 in vivo. The expression of circ_KIAA1199 was elevated in CRC. Circ_KIAA1199 downregulation suppressed CRC cell proliferation, survival, migration and invasion. MiR-34c-5p was a target of circ_KIAA1199. The effects of circ_KIAA1199 downregulation were reversed by miR-34c-5p deficiency. In addition, MSI1 was a target of circ_KIAA1199, and the inhibitory effects of miR-34c-5p restoration on CRC cell proliferation, survival, migration and invasion were reversed by MSI1 overexpression. Circ_KIAA1199 positively regulated MSI1 expression by targeting miR-34c-5p. Moreover, circ_KIAA1199 knockdown blocked tumor growth in animal models. Circ_KIAA1199 functioned as an oncogene to drive the malignant development of CRC by activating MSI1 via competitively targeting miR-34c-5p.

Identification of TAPBPL as a novel negative regulator of T-cell function.

T cell stimulatory and inhibitory molecules are critical for the regulation of immune responses. In this study, we identify a novel T cell co‐inhibitory molecule TAPBPL, whose amino acid sequence shares homology with known B7 family members. TAPBPL protein is expressed on resting and activated T cells, B cells, monocytes, and dendritic cells (DCs), as well as on some tumor tissues. The putative TAPBPL receptor is expressed on activated CD4 and CD8 T cells. A soluble recombinant human TAPBPL‐IgG Fc (hTAPBPL‐Ig) fusion protein inhibits the proliferation, activation, and cytokine production of both mouse and human T cells in vitro. In vivo administration of hTAPBPL‐Ig protein attenuates experimental autoimmune encephalomyelitis (EAE) in mice. Furthermore, an anti‐TAPBPL monoclonal antibody neutralizes the inhibitory activity of hTAPBPL‐Ig on T cells, enhances antitumor immunity, and inhibits tumor growth in animal models. Our results suggest that therapeutic intervention of the TAPBPL inhibitory pathway may represent a new strategy to modulate T cell‐mediated immunity for the treatment of cancer, infections, autoimmune diseases, and transplant rejection.

Mesenchymal Stromal Cell-derived Extracellular Vesicles in Preclinical Animal Models of Tumor Growth: Systematic Review and Meta-analysis.

Mesenchymal stromal cell derived extracellular vesicles (MSC-EVs) have been implicated in the regulation of tumor growth. Studies remain preclinical with effects ranging from inhibition of tumor growth to cancer progression. A systematic review and meta-analysis is needed to clarify the effect of MSC-EVs on tumor growth to facilitate potential translation to clinical trials. A systematic search of the literature (MEDLINE, Embase, and BIOSIS databases to June 1, 2019) identified all pre-clinical controlled studies investigating the effect of MSC-EVs on tumor growth. Study selection and data extraction were performed in duplicate. Potential risk of bias was assessed using the SYRCLE tool. A random effects meta-analysis of reduction in tumor weight/volume (primary outcome) was performed. We identified 29 articles and 22 reported data on tumor responses that were included for meta-analysis. Studies were associated with unclear risk of bias in a large proportion of domains in accordance with the SYRCLE tool for determining risk of bias in preclinical studies. A high risk of bias was not identified in any study. MSC-EVs had a mixed response on tumor progression with some studies reporting inhibition of tumor growth and others reporting tumor progression. Overall, MSC-EVs exerted a non-significant reduction in tumor growth compared to controls (standardized mean difference (SMD) -0.80, 95 % CI -1.64 to 0.03, p = 0.06, I2 = 87 %). Some studies reported increased tumor growth which aligned with their stated hypothesis and some interrogated mechanisms in cancer biology. EVs isolated from MSCs that overexpressed anti-tumor RNAs were associated with significant tumor reduction in meta-analysis (SMD - 2.40, 95 % CI -3.36 to -1.44, p < 0.001). Heterogeneity between studies was observed and included aspects of study design such as enrichment of MSC-EVs with specific anti-tumor molecules, tissue source of MSCs, method of EV isolation, characterization of MSCs and EVs, dosage and administration schedules, and tissue type and source of tumor cells studied. MSC-EVs are associated with mixed effects on tumor growth in animal models of cancer. In studies where anti-tumor RNAs are packaged in EVs, a significant reduction in tumor growth was observed. Reducing heterogeneity in study design may accelerate our understanding of the potential effects of MSC-EVs on cancer. [274 words] Forest plot of MSC-EV effect on tumor growth accordinggenetic modification of EVs in animal studies identified from a systematicreview of the literature. All cohorts from studies with multiple interventiongroups are presented separately with control groups divided equally among thegroups. M, modified; H, hypoxia.