Orthotopic Tumor Growth Research Articles

HIF1A signaling selectively supports proliferation of breast cancer in the brain

Blood-borne metastasis to the brain is a major complication of breast cancer, but cellular pathways that enable cancer cells to selectively grow in the brain microenvironment are poorly understood. We find that cultured circulating tumor cells (CTCs), derived from blood samples of women with advanced breast cancer and directly inoculated into the mouse frontal lobe, exhibit striking differences in proliferative potential in the brain. Derivative cell lines generated by serial intracranial injections acquire selectively increased proliferative competency in the brain, with reduced orthotopic tumor growth. Increased Hypoxia Inducible Factor 1A (HIF1A)-associated signaling correlates with enhanced proliferation in the brain, and shRNA-mediated suppression of HIF1A or drug inhibition of HIF-associated glycolytic pathways selectively impairs brain tumor growth while minimally impacting mammary tumor growth. In clinical specimens, brain metastases have elevated HIF1A protein expression, compared with matched primary breast tumors, and in patients with brain metastases, hypoxic signaling within CTCs predicts decreased overall survival. The selective activation of hypoxic signaling by metastatic breast cancer in the brain may have therapeutic implications.

Tumor cell endogenous HIF-1α activity induces aberrant angiogenesis and interacts with TRAF6 pathway required for colorectal cancer development

Hypoxia and inflammation are key factors for colorectal cancer tumorigenesis. The colonic epithelium belongs to the tissues with the lowest partial pressure of oxygen in the body, and chronic inflammation is associated with an increased chance to develop colon cancer. How the colonic epithelium responds to hypoxia and inflammation during tumorigenesis remains to be elucidated. Here we show, that murine colon adenocarcinoma cells with attenuated response to hypoxia, due to a knock-down (KD) of HIF-1α, produce smaller and less hypoxic tumors in an orthotopic mouse model when compared to tumors induced with control cells. HIF-1α-KD tumors showed more functional perfused vasculature associated with increased levels of vessel-stabilizing factors and reduced levels of proangiogenic factors, including extracellular matrix protein Cyr61/CCN1. Intratumoral injection of Cyr61 in HIF-1α-KD tumors revealed an in increased vessel permeability and tumor hypoxia. Further bioinformatics analysis identified a possible interaction between HIF-1α and TRAF6, an upstream effector of the NF-κB pathway that was confirmed by coimmunoprecipitation in MC-38 and CT26 colon adenocarcinoma cells and in situ by proximity ligation assay. Down-regulation of TRAF6 resulted in virtual abrogation of orthotopic tumor growth. Subcutaneous TRAF6-KD tumors were smaller and contained reduced vessel size and differently polarized macrophages. These data demonstrate that the tumor cell response to increased hypoxia in the colon leads to promotion of nonfunctional angiogenesis, regulated by both hypoxia and TRAF6 pathways.

The Antidiabetic Agent Acarbose Improves Anti-PD-1 and Rapamycin Efficacy in Preclinical Renal Cancer.

Simple SummaryAlthough immune-stimulatory and targeted therapies benefit many patients with metastatic kidney cancer, a sizeable proportion of patients fail to respond. Recent studies in mice demonstrate that nutrient-limiting dietary interventions can improve responses to chemotherapy. However, these studies did not investigate effects on metastasis, and the impact of these interventions on the response to immunotherapy or targeted therapies in kidney cancer is unknown. We therefore studied the effects of a glucose-limiting drug called acarbose, which is used to treat type 2 diabetes, in a spontaneously-metastasizing mouse model of kidney cancer. We found that acarbose slowed kidney cancer growth and promoted protective immune responses. In combination with either an immunotherapy or a targeted therapy used clinically to treat kidney cancer, acarbose led to improved treatment outcomes and reduced lung metastases. Our findings contribute to the emerging idea of using nutrition-based interventions to enhance responses to cancer treatments. Although immune checkpoint inhibitors and targeted therapeutics have changed the landscape of treatment for renal cell carcinoma (RCC), most patients do not experience significant clinical benefits. Emerging preclinical studies report that nutrition-based interventions and glucose-regulating agents can improve therapeutic efficacy. However, the impact of such agents on therapeutic efficacy in metastatic kidney cancer remains unclear. Here, we examined acarbose, an alpha-glucosidase inhibitor and antidiabetic agent, in a preclinical model of metastatic kidney cancer. We found that acarbose blunted postprandial blood glucose elevations in lean, nondiabetic mice and impeded the growth of orthotopic renal tumors, an outcome that was reversed by exogenous glucose administration. Delayed renal tumor outgrowth in mice on acarbose occurred in a CD8 T cell-dependent manner. Tumors from these mice exhibited increased frequencies of CD8 T cells that retained production of IFNγ, TNFα, perforin, and granzyme B. Combining acarbose with either anti-PD-1 or the mammalian target of rapamycin inhibitor, rapamycin, significantly reduced lung metastases relative to control mice on the same therapies. Our findings in mice suggest that combining acarbose with current RCC therapeutics may improve outcomes, warranting further study to determine whether acarbose can achieve similar responses in advanced RCC patients in a safe and likely cost-effective manner.

Raloxifene inhibits pancreatic adenocarcinoma growth by interfering with ER\u03b2 and IL-6/gp130/STAT3 signaling

PurposeCurrently, the exact role of estrogen receptor (ER) signaling in pancreatic cancer is unknown. Recently, we showed that expression of phosphorylated ERβ correlates with a poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). Here, we hypothesized that raloxifene, a FDA-approved selective ER modulator (SERM), may suppress PDAC tumor growth by interfering with ERβ signaling. To test this hypothesis, we studied the impact of raloxifene on interleukin-6/glycoprotein-130/signal transducer and activator of transcription-3 (IL-6/gp130/STAT3) signaling.MethodsHuman PDAC cell lines were exposed to raloxifene after which growth inhibition was assessed using a BrdU assay. ER knockdown was performed using siRNAs specific for ERα and ERβ. The effects of raloxifene on IL-6 expression and STAT3 phosphorylation in PDAC cells were assessed by ELISA and Western blotting, respectively. In addition, raloxifene was administered to an orthotopic PDAC tumor xenograft mouse model, after which tumor growth was monitored and immunohistochemistry was performed.ResultsRaloxifene inhibited the in vitro growth of PDAC cells, and this effect was reversed by siRNA-mediated knockdown of ERβ, but not of ERα, indicating ER isotype-specific signaling. We also found that treatment with raloxifene inhibited the release of IL-6 and suppressed the phosphorylation of STAT3Y705 in PDAC cells. In vivo, we found that orthotopic PDAC tumor growth, lymph node and liver metastases as well as Ki-67 expression were reduced in mice treated with raloxifene.ConclusionsInhibition of ERβ and the IL-6/gp130/STAT3 signaling pathway by raloxifene leads to potent reduction of PDAC growth in vitro and in vivo. Our results suggest that ERβ signaling and IL-6/gp130 interaction may serve as promising drug targets for pancreatic cancer and that raloxifene may serve as an attractive therapeutic option for PDAC patients expressing the ERβ isotype.

Nanotheranostics With the Combination of Improved Targeting, Therapeutic Effects, and Molecular Imaging.

There is an increasing interest in the design of targeted carrier systems with combined therapeutic and diagnostic modalities. Therapeutic modalities targeting tumors with single ligand-based targeting nanocarriers are insufficient for proficient delivery and for targeting two different surface receptors that are overexpressed in cancer cells. Here, we evaluated an activated nanoparticle delivery system comprising fucoidan/hyaluronic acid to improve therapeutic efficacy. The system comprised polyethylene glycol-gelatin-encapsulated epigallocatechin gallate (EGCG), poly (D,L-lactide-co-glycolide; PLGA), and stable iron oxide nanoparticles (IOs). The latter enables targeting of prostate cancers in their molecular images. We demonstrate the transfer of nanoparticles and their entry into prostate cancer cells through ligand-specific recognition. This system may prove the benefits of drug delivery that enhances the inhibition of cell growth through apoptosis induction. Moreover, the improved targeting of nanotheranostics significantly suppressed orthotopic prostate tumor growth and more accurately targeted tumors compared with systemic combination therapy. In the presence of nanoparticles with iron oxides, the hypointensity of the prostate tumor was visualized on a T2-weignted magnetic resonance image. The diagnostic ability of this system was demonstrated by accumulating fluorescent nanoparticles in the prostate tumor from the in vivo imaging system, computed tomography. It is suggested that theranostic nanoparticles combined with a molecular imaging system can be a promising cancer therapy in the future.

Blockade of the Short Form of Prolactin Receptor Induces FOXO3a/EIF-4EBP1-Mediated Cell Death in Uterine Cancer.

Abnormal activity of human prolactin (PRL) and its membrane-associated receptor (PRLR) contributes to the progression of uterine carcinoma. However, the underlying mechanisms are not well understood, and current means of targeting the PRL/PRLR axis in uterine cancer are limited. Our integrated analyses using The Cancer Genome Atlas and Genotype-Tissue Expression (GTEx) databases demonstrated that a short form of PRLR (PRLR_SF) is the isoform predominantly expressed in human uterine cancers; expression of this PRLR_SF was elevated in uterine cancers in comparison with cancer-free uterine tissues. We hypothesized that the overexpression of PRLR_SF in uterine cancer cells contributes, in part, to the oncogenic activity of the PRL/PRLR axis. Next, we employed G129R, an antagonist of human PRL, to block the PRL/PRLR axis in both PTEN wt and PTEN mut orthotopic mouse models of uterine cancer. In comparison with control groups, treatment with G129R as monotherapy or in combination with paclitaxel resulted in a significant reduction of growth and progression of orthotopic uterine tumors. Results from protein profiling of uterine cancer cells and in vivo tumors revealed a set of new downstream targets for G129R. Our results showed that G129R induced sub-G0 population arrest, decreased nascent protein synthesis, and initiated FOXO3a/EIF-4EBP1-mediated cell death in both PTEN wt and PTEN mut uterine cancer cells. Collectively, our results show a unique pattern of PRLR_SF expression predominantly in uterine cancer. Moreover, FOXO3a and EIF-4EBP1 are important mediators of cell death following G129R treatment in uterine cancer models.

Protein Kinase C Alpha (PKCα) overexpression leads to a better response to retinoid acid therapy through Retinoic Acid Receptor Beta (RARβ) activation in mammary cancer cells.

Retinoids have proved to be effective for hematologic malignancies treatment but till nowadays, their use as single agent for the solid tumor's management is still controversial. All-trans retinoic acid (ATRA), the main active metabolite of vitamin A, exerts non-genomic interactions with different members of the protein kinase C (PKC) family, recognized modulators of different tumor progression pathways. To determine whether a group of patients could become benefited employing a retinoid therapy, in this study we have evaluated whether PKCα expression (a poor prognosis marker in breast cancer) could sensitizes mammary cells to ATRA treatment. PKCα overexpression was achieved by stable transfection and confirmed by western blot. Transfected PKC functionality was determined by nuclear translocation-induction and confocal microscopy. In vitro proliferation was evaluated by cell counting and cell cycle distribution was analyzed by flow cytometry. In vivo studies were performed to evaluate orthotopic tumor growth and experimental lung colonization. Retinoic acid response elements (RARE) and AP1 sites-dependent activity was studied by gene reporter assays and retinoic acid receptors (RARs) were measured by RT-qPCR. Our findings suggest that high PKCα levels improve the differentiation response to ATRA in a RAR signaling-dependent manner. Moreover, RARβ expression appears to be critical to induce ATRA sensitization, throughout AP1 trans-repression. Here we propose that retinoids could lead a highly personalized anticancer treatment, bringing benefits to patients with aggressive breast tumors resulting from high PKCα expression but, an adequate expression of the RARβ receptor is required to ensure the effect on this process.

A Natural Flavone Tricin from Grains Can Alleviate Tumor Growth and Lung Metastasis in Colorectal Tumor Mice.

Tricin, a flavone isolated from rice bran, has been shown to be chemopreventive in a colorectal cancer (CRC) mouse model. This study aimed to illustrate the inhibitory activities of tricin in colon cancer cells and in a metastatic CRC mouse model. BALB/c mice injected with mouse Colon26-Luc cells into the rectum wall were treated with tricin (37.5 mg/kg) daily for 18 days. Orthotopic colon tumor growth and metastasis to lungs were assessed by in vivo bioluminescence imaging. Results showed that tricin suppressed Colon-Luc cells motility and downregulated phosphorylated Akt, Erk1/2 and NF-κB expressions of human colon cancer HT-29 cells. While tricin treatment suppressed tumor growth and lung metastasis as well as altered the populations of myeloid-derived suppressor cells and regulatory T cells in spleens. In summary, the tumor microenvironment modulatory and anti-metastatic effects of tricin in colon cancer mouse model were shown for the first time, suggesting the potential development of tricin-containing food supplements for CRC patients.

Abstract 1936: Immunoproteasome inhibitors for the treatment of ALL

Abstract The t(4;11)(q21;q23) chromosomal translocation that creates MLL-AF4 fusion protein confers a poor prognosis protein in infant acute lymphoblastic leukemia (ALL). This translocation also sensitizes cells to proteasome inhibitors bortezomib and carfilzomib, which are approved by the FDA for the treatment of multiple myeloma. Clinical activity of bortezomib in combination with standard chemotherapy has been documented in several clinical trials of ALL patients, and a case of a single-agent activity against relapsed leukemia driven by MLL-AF4 translocation has been described. However, toxicities of bortezomib and carfilzomib may be unacceptable to pediatric patients. We found that the overwhelming majority of proteasomes in this subtype of ALL are lymphoid tissue specific immunoproteasomes. Cells with MLL-AF4 translocations were sensitive to pharmacologically relevant concentrations of specific immunoproteasome inhibitor ONX-0914. Furthermore, ONX-0914 dramatically delayed growth of orthotopic xenograft tumors in mice. Thus, immunoproteasomes are therapeutic targets in ALL; replacing bortezomib and carfilzomib with immunoproteasome inhibitors in ALL should reduce toxicities associated with inhibition of the proteasomes in non-lymphoid tissues. Citation Format: Tyler W. Jenkins, Sondra Downey-Kopyscinski, William C. Colley, Jennifer L. Fields, Steven N. Fiering, Alexei F. Kisselev. Immunoproteasome inhibitors for the treatment of ALL [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1936.

Endothelial p130cas Confers Resistance to Anti-Angiogenesis Therapy

Adaptive resistance to vascular endothelial growth factor (VEGF)–targeted therapies occurs frequently among cancer patients. To investigate the underlying mechanisms, we established an array of orthotopic mouse models of ovarian cancer with adaptive resistance to anti-VEGF antibodies (AVAs). Genomic profiling showed an important role of endothelial p130cas in AVA resistant tumors. AVA treatment induced internalization of a p130cas/VEGFR2/TNKS1BP1 (a tankyrase-1–binding protein) complex in endothelial cells and initiated cell death and autophagy; knockdown of LC3B or caspase-10 reversed cells’ resistance to AVA treatment. Targeting host p130cas reduced the growth of AVA-resistant orthotopic ovarian tumors. Genomic ablation of vascular p130cas in p130casflox/floxTie2Cre mice significantly prolonged survival of mice carrying syngeneic ovarian tumors with adaptive resistance to AVA therapy. In ovarian cancer patients, higher p130cas expression in tumor-associated vasculature was associated with higher mortality. Collectively, these findings have important implications to guide future therapeutic strategies to overcome resistance to anti-angiogenic therapy.

Abstract 2442: Identification of a novel role for the β-catenin/CBP signaling in epigenetic regulation of the N-glycosylation gene, DPAGT1, in head and neck cancer

Abstract Aberrant activation of the DPAGT1 gene, encoding an essential enzyme in the metabolic pathway of protein N-glycosylation, has been shown to be associated with head and neck squamous cell carcinoma (HNSCC). We have shown that DPAGT1 inhibits intercellular adhesion and functions in a positive feedback loop with Wnt/β-catenin signaling, and that the nuclear β-catenin/CBP signaling underlies the progression of HNSCC to advanced disease. However, the tumor promoting effects of DPAGT1 and its molecular links to the nuclear β-catenin/CBP axis are not well defined. We carried out genomic and functional analyses of DPAGT1 perturbation in indolent (CAL27) and metastatic (HSC-3) HNSCC cells, and in orthotopic HSC-3-derived xenografts in mice. We further generated and annotated DPAGT1 inhibition signature in HSC-3 cells and interrogated it in TCGA HNSCC. We then examined the effects of inhibition of β-catenin-CBP interaction with E7386 on DPAGT1 expression using ChIP-seq and computational approaches. E7386, a novel β-catenin/CBP modulator displays activity profile that closely overlaps with that of ICG-001, but exhibits ~50 - 100-fold lower EC50 values. Ectopic expression of DPAGT1 in indolent CAL27 cells induced epithelial-to-mesenchymal transition (EMT) which coincided with increased abundance of active β-catenin. Partial knockdown of DPAGT1 with siRNA in metastatic HSC-3 cells inhibited EMT, diminished cell migration and enhanced intercellular adhesion. Inhibition of the DPAGT1 enzyme activity using tunicamycin interfered with orthotopic tongue tumor growth and metastasis. DPAGT1 knockdown in HSC-3 cells defined DPAGT1-activated gene signature as enriched in pro-tumorigenic signaling pathways, including stem cell-like genes. Integrative analysis of the DPAGT1-activated genes in TCGA validated the association of DPAGT1 activity with the EMT transcription factors, ZEB1, Twist1/2 and Slug. ChIP-seq analyses without and with the E7386 treatment revealed reduced occupancy of H3K4me3 at two DPAGT1 transcription start sites following the E7386 treatment. In conclusion, our studies align aberrant activation of DPAGT1 with the induction of EMT and stem cell associated genes and suggest a novel role of β-catenin/CBP/MLL1 in the epigenetic regulation DPAGT1 and protein N-glycosylation in HNSCC. Citation Format: Khalid A. Alamoud, Vinay Kartha, Huamei Yang, Andrew Tilston-Lunel, Anthony Federico, Manish Bais, Takachi Owa, Kenichi Nomoto, Xalarabos Varelas, Stefano Monti, Maria A. Kukuruzinska. Identification of a novel role for the β-catenin/CBP signaling in epigenetic regulation of the N-glycosylation gene, DPAGT1, in head and neck cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2442.

Abstract 6045: Interferon signaling induces NAD(H) consumption via PARP9/10/14 and sensitizes pancreatic cancer cells to NAMPT inhibition

Abstract Interferons (IFNs) are critical cytokines which, in the tumor microenvironment, have the potential to trigger targetable vulnerabilities. Pancreatic ductal adenocarcinoma (PDAC) has an extensively reprogrammed metabolic network in which nicotinamide adenine dinucleotide (NAD) is required as a co-factor for critical cell processes. NAMPT is the rate-limiting enzyme in the NAD salvage pathway, which is the dominant source of NAD in cancer cells. Findings from clinical trials with NAMPT inhibitors (NAMPTi) suggest the need to identify patient subsets that are highly sensitive to NAD depletion. An NAD assay was used to profile the effect of type I IFN signaling and NAMPTi on NAD levels in a panel of 12 human PDAC models. The effect of this NAD reduction was profiled in vitro with cell proliferation and mitochondrial respiration assays, Incucyte cell imaging, and flow cytometry for DNA damage (pH2A.X assay) and apoptosis (Annexin V assay). After confirmation of the synergy between IFN signaling and NAMPTi, a high throughput screen was performed to identify drugs that are potentiated by reduced NAD levels. Inhibition of PDAC proliferation and induction of DNA damage and apoptosis with the combination treatment was validated in vitro using the same assays previously described. In vivo studies were then performed with orthotopic tumor models (with Luciferase labeling for bioluminescence imaging) and patient-derived xenograft (PDX) models. We found that IFN signaling, present in a subset of PDAC tumors, substantially lowered NAD(H) levels through upregulating the expression of NAD consuming enzymes PARP9, PARP10, and PARP14. IFN and NAMPTi collaboratively reduced NAD levels in PDAC cells, inhibited PDAC cell proliferation and invasion in vitro, and suppressed orthotopic PDAC tumor growth and liver metastasis in vivo. We then identified clinical oncology drugs more potent in PDAC cells with lower NAD levels induced by IFN and NAMPTi, which included DNA-damaging compounds Gemcitabine (GEM) and Paclitaxel (PTX). Mechanistically, the NAD-dependent PARP family members are critical in DNA repair. Their activity can be monitored by measuring PAR abundance, which was substantially reduced by IFNβ and NAMPTi with and without the GEM/PTX combination. NAD(H) reduction and GEM/PTX collaboratively enhanced phosphorylation of CHEK2, a marker of DNA damage response, and triggered PDAC cell apoptosis. All of these findings were rescued by nicotinamide riboside (NR) supplementation (which bypasses the need for rate-limiting NAMPT in NAD synthesis), validating that these findings were due to the effect of on-target NAD(H) reduction. Our findings predict that using PARP9/10/14 as biomarkers will allow the identification of PDAC patients whose tumors have relatively low NAD(H) levels, which we hypothesize would render them vulnerable to combination therapies with NAMPTi and DNA damaging agents. Citation Format: Alexandra M. Moore, Lei Zhou, Shili Xu, Timothy R. Donahue. Interferon signaling induces NAD(H) consumption via PARP9/10/14 and sensitizes pancreatic cancer cells to NAMPT inhibition [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6045.

Overexpression of pyruvate dehydrogenase phosphatase 1 promotes the progression of pancreatic adenocarcinoma by regulating energy-related AMPK/mTOR signaling

BackgroundHuman pyruvate dehydrogenase phosphatase 1 (PDP1) plays an important physiological role in energy metabolism; however, its expression and function in human pancreatic adenocarcinoma (PDAC) remain unknown. This study aimed to investigate the expression pattern and mechanisms of action of PDP1 in human PDAC.MethodsThe expression pattern of PDP1 in PDAC was determined, and its correlation with patient survival was analyzed. Ectopic expression or knockdown of PDP1 was performed, and in vitro proliferation and migration, as well as in vivo tumor growth of PDAC, were measured. The mechanism was studied by biochemical approaches.ResultsPDP1 was overexpressed in human PDAC samples, and high expression of PDP1 correlated with poor overall and disease-free survival of PDAC patients. PDP1 promoted the proliferation, colony formation, and invasion of PDAC cells in vitro and facilitated orthotopic tumor growth in vivo. PDP1 accelerated intracellular ATP production, leading to sufficient energy to support rapid cancer progression. mTOR activation was responsible for the PDP1-induced tumor cell proliferation and invasion in PDAC. AMPK was downregulated by PDP1 overexpression, resulting in mTOR activation and cancer progression.ConclusionOur findings suggested that PDP1 could be a promising diagnostic and therapeutic target for anti-PDAC treatment.

Abstract A01: Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) for the treatment of bladder cancer

Abstract Bladder cancer remains a leading cause of death and one of the most expensive cancers to treat in the United States. Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) is a personalized therapeutic approach that has the potential to treat bladder cancer at every stage of disease. We have previously demonstrated the ability to expand tumor reactive T cells from transurethral resection, radical cystectomy, and metastatic lymph node tumor specimens collected from bladder cancer patients. In this study, our goal is to investigate different delivery approaches of ACT in vivo to determine the best strategy to decrease tumor burden and advise clinical trial design. Experiments were performed using MB49 murine bladder cancer cells transfected to express ovalbumin (MB49OVA). MB49OVA cells are recognized by OVA-specific OT-I T cells as determined by IFN-gamma production in vitro. Our methods include both subcutaneous and orthotopic bladder tumor models. In vivo, we first tested systemic delivery of OT-I T cells (5.0 × 10e6) by tail vein injection after lymphodepletion with a regimen of cyclophosphamide followed by fludarabine in mice bearing subcutaneous MB49OVA tumors. ACT-treated mice experienced significant tumor regression (p=0.02), improved survival (median survival PBS=47 days, ACT=undefined, p=0.01), and increased tumor infiltration of CD3+, CD4+, and CD8+ T cells. OT-I T cells as well as endogenous OVA-specific CD8+ T cells were detectable in the spleens and tumors of treated mice. Next we tested the efficacy of intravesical delivery of OT-I T cells in mice bearing orthotopic MB49OVA tumors, without prior lymphodepletion. OT-I T cells (4.0 × 10e6) were delivered directly to the bladder via catherization and tumor growth was monitored weekly via ultrasound imaging. Infiltration of CellTrace Violet-labeled OT-I T cells into orthotopic tumors was detected after 3 hours of incubation by flow cytometry analysis of resected tumor. Orthotopic bladder tumor growth was significantly abrogated in ACT-treated mice compared with PBS control-treated mice (p=0.001) and improved survival was observed (median survival PBS=35 days, ACT=undefined). An increase in CD8+ T-cell infiltration was measured in tumors of mice at day 60 post treatment. In order to evaluate the efficacy of TIL transfer in these bladder tumor models, T cells infiltrating subcutaneous MB49OVA tumors were isolated and cultured in vitro in media containing IL-2. After 1 week, bladder TIL demonstrated reactivity against MB49OVA and MB49 parental cells as determined by IFN-gamma production. Future work will implement the adoptive transfer of MB49 TIL for the treatment of orthotopic bladder tumors alone or in combination with anti-PD-L1 therapy. Taken together, these data suggest that ACT using bladder tumor-specific T cells has the potential to reduce bladder tumor burden when given either systemically or intravesically directly into the bladder. Citation Format: Brittany L. Bunch, Jennifer Morse, Sarah Asby, Michael Poch, Shari Pilon-Thomas. Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) for the treatment of bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr A01.

Self-Assembly Protein Superstructures as a Powerful Chemodynamic Therapy Nanoagent for Glioblastoma Treatment

HighlightsA new type of protein nanostructure as a chemodynamic therapy nanoagent was fabricated via proper assembling and crosslinking techniques.The as-fabricated nanostructures could cross the blood–brain barrier, possessing excellent long circulating times and accumulation properties at the tumor site.The RBC@Hb@GOx NPs can be regarded as ‘pure particles of drugs,’ which can produce toxic reactive oxygen species to inhibit the growth of orthotopic brain tumor.

Exopolysaccharide from Cryptococcus heimaeyensis S20 induces autophagic cell death in non-small cell lung cancer cells via ROS/p38 and ROS/ERK signalling.

Objectives Cryptococcus heimaeyensis S20 is found in Antarctica and can produce exopolysaccharides (CHEPS). Here, we explore the anti‐tumour effects of CHEPS on non‐small cell lung cancer (NSCLC).Materials and methodsCell viability was assessed by CCK8 and colony formation assays. Flow cytometry was used to analyse the cell cycle, cell apoptosis and reactive oxygen species (ROS). Cell autophagy was detected by EGFP‐LC3 puncta assay, Lyso‐Tracker Red staining and transmission electron microscopy. mRNA and protein levels were analysed by qRT‐PCR and Western blot. Related mechanisms were confirmed using appropriate inhibitors or shRNA. In vitro results were further confirmed by a tumour xenograft study.ResultsCHEPS inhibited the proliferation of NSCLC cells by inducing S‐ and G2/M‐phase arrest and autophagic cell death, but not apoptosis. CHEPS was less toxic to normal human embryonic lung fibroblasts. CHEPS activated the MAPK pathway in NSCLC cells, and p38 and ERK promoted CHEPS‐induced cell death. Further studies showed that p38 and ERK promoted CHEPS‐induced NSCLC cell autophagy and ERK promoted CHEPS‐induced S‐ and G2/M‐phase arrest. ROS were induced by CHEPS. A ROS scavenger attenuated CHEPS‐induced p38 and ERK activation, autophagy and cell death. Finally, CHEPS reduced orthotopic lung tumour growth without organ‐related toxicity. CHEPS also induced ROS, activated p38 and ERK, and triggered autophagy in vivo.ConclusionsCHEPS induces autophagic cell death and S‐ and G2/M‐phase arrest in NSCLC cells via ROS/p38 and ROS/ERK signalling.

Discovery of Isoplumbagin as a Novel NQO1 Substrate and Anti-Cancer Quinone.

Isoplumbagin (5-hydroxy-3-methyl-1,4-naphthoquinone), a naturally occurring quinone from Lawsonia inermis and Plumbago europaea, has been reported to have anti-inflammatory and antimicrobial activity. Inflammation has long been implicated in cancer progression. In this study, we examined the anticancer effect of chemically synthesized isoplumbagin. Our results revealed that isoplumbagin treatment suppressed cell viability and invasion of highly invasive oral squamous cell carcinoma (OSCC) OC3-IV2 cells, glioblastoma U87 cells, non-small cell lung carcinoma H1299 cells, prostate cancer PC3 cells, and cervical cancer HeLa cells by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Boyden chamber assays. In vivo studies demonstrate the inhibitory effect of 2 mg/kg isoplumbagin on the growth of orthotopic xenograft tumors derived from OSCC cells. Mechanistically, isoplumbagin exerts its cytotoxic effect through acting as a substrate of reduced nicotinamide adenine dinucleotide phosphate [NAD(P)H] dehydrogenase quinone 1 (NQO1) to generate hydroquinone, which reverses mitochondrial fission phenotype, reduces mitochondrial complex IV activity, and thus compromises mitochondrial function. Collectively, this work reveals an anticancer activity of isoplumbagin mainly through modulating mitochondrial dynamics and function.

STAT3 Inhibition by Centipede Scolopendra Extract in Liver Cancer HepG2 Cells and Orthotopic Mouse Models of Hepatocellular Carcinoma

ObjectiveTo observe the effects of Centipede Scolopendra extraction (CSE) on human liver cancer HepG2 cells and the nude mouse tumor model of liver orthotopic transplantation, and to explore the anti-liver cancer mechanism of the extract. MethodsHepG2 cells were respectively treated with CSE250 (250 μg/mL), CSE500 (500 μg/mL) and 5-FU, and control group was established. An enzymatic hydrolysis and acetone precipitation method was used to separate and purify CSE, which was then used to treat HepG2 cells. The CCK8 assay was used to detect the inhibition of cell proliferation and the half maximal inhibitory concentration (IC50) was calculated. Flow cytometry was used to analyze the cell cycle, and western blot was used to detect the expression of signal transduction and activator of transcription 3 (STAT3) pathway-related proteins in HepG2 cells treated with CSE. A nude mouse model with an orthotopic liver tumor was prepared. The mice were randomly divided into four groups, each containing 12 animals: the model group, the 5-FU group, the CSE10 group [10 mg/(kg·d)] and the CSE50 group [50 mg/(kg·d)]. The volume and mass changes in the nude mice with orthotopic transplanted tumors were observed. Western blot method was used to test the protein expression levels of p-STAT3 and p38 mitogen-activated protein kinase (p38MAPK). Tissues from the liver of mice in the model group and the CSE50 group were analyzed by using a protein tyrosine kinase (PTK) chip, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) function enrichment analysis of the differentially expressed proteins was performed. ResultsThis study showed that CSE significantly inhibited the proliferation of HepG2 cells (P < 0.05). After 48 h of CSE treatment, the cell cycle of HepG2 cells manifested as S phase and G2/M phase; p-STAT3 protein levels in the CSE groups were significantly lower than that in the control group (P < 0.05). Analysis of the tumor inhibition in the mice showed that the tumor masses and volume in CSE groups were lower (P < 0.05). The protein levels of p-STAT3 and p38MAPK in CSE50 group and 5-FU group decreased significantly (P < 0.05). PTK antibody chip screening results showed that CSE groups had a bidirectional regulation trend, and there were 23 up-regulated PTKs and six down-regulated PTKs. The GO and KEGG analyses showed that CSE exerted its anticancer effects through regulation of biological processes, including mitogen-activated protein kinase (MAPK) cascade, chemotaxis, cell invasion, cell adhesion, angiogenesis and other biological processes, and through signaling pathways, including the MAPK, phosphatidylinositol-3-kinase/serine threonine protein kinase (PI3K/AKT), and RAS signaling pathways. ConclusionsCSE can effectively inhibite the proliferation of HepG2 cells and effectively inhibite the growth of liver cancer orthotopic transplantation tumor. Its mechanism may be closely related to the regulation of STAT3, MAPK and PI3K/AKT signaling pathways.

Development and optimization of orthotopic liver metastasis xenograft mouse models in uveal melanoma

BackgroundPatients with metastatic uveal melanoma (MUM) in the liver usually die within 1 year. The development of new treatments for MUM has been limited by the lack of diverse MUM cell lines and appropriate animal models. We previously reported that orthotopic xenograft mouse models established by direct injection of MUM cells into the liver were useful for the analysis associated with tumor microenvironment in the liver. However, considering that patients with UM metastasize to the liver hematogenously, direct liver injection model might not be suitable for investigation on various mechanisms of liver metastasis. Here, we aim to establish new orthotopic xenograft models via hematogenous dissemination of tumor cells to the liver, and to compare their characteristics with the hepatic injection model. We also determine if hepatic tumors could be effectively monitored with non-invasive live imaging.MethodstdtTomate-labeled, patient-derived MUM cells were injected into the liver, spleen or tail vein of immunodeficient NSG mice. Tumor growth was serially assessed with In Vivo Imaging System (IVIS) images once every week. Established hepatic tumors were evaluated with CT scan and then analyzed histologically.ResultsWe found that splenic injection could consistently establish hepatic tumors. Non-invasive imaging showed that the splenic injection model had more consistent and stronger fluorescent intensity compared to the hepatic injection model. There were no significant differences in tumor growth between splenic injection with splenectomy and without splenectomy. The splenic injection established hepatic tumors diffusely throughout the liver, while the hepatic injection of tumor cells established a single localized tumor. Long-term monitoring of tumor development showed that tumor growth, tumor distribution in the liver, and overall survival depended on the number of tumor cells injected to the spleen.ConclusionWe established a new orthotopic hepatic metastatic xenograft mouse model by splenic injection of MUM cells. The growth of orthotopic hepatic tumors could be monitored with non-invasive IVIS imaging. Moreover, we evaluated the therapeutic effect of a MEK inhibitor by using this model. Our findings suggest that our new orthotopic liver metastatic mouse model may be useful for preclinical drug screening experiments and for the analysis of liver metastasis mechanisms.

Cancer cell-derived interleukin-33 decoy receptor sST2 enhances orthotopic tumor growth in a murine pancreatic cancer model

Proinflammatory interleukin-33 (IL-33) binds to its receptor ST2L and is involved in inflammation and the malignant behavior of cancer cells. However, the role of IL-33-ST2L and the IL-33 decoy receptor sST2 in the tumor microenvironment of pancreatic cancer is unclear. Because we previously reported that sST2 derived from colon cancer cells profoundly influences malignant tumor growth, we hypothesized that sST2 released from pancreatic cancer cells also modulates IL-33-ST2L signaling in the tumor microenvironment, thereby influencing tumor growth. ST2 (ST2L and sST2) expression in mouse pancreatic cancer Panc02 cells was downregulated by shRNAs. mRNA expression levels of IL-33, ST2, cytokines and chemokines in the cells and tumor tissues were examined using real-time PCR. sST2 secretion and the amount of CXCL3 in tumor tissues were measured using ELISA. Tumor growth was investigated after injection of the cells into the pancreas of C57BL/6 mice. MPO+, F4/80+ and CD20+ cells in tumor tissues were detected using immunohistochemistry. Some but not all human and mouse pancreatic cancer cell lines preferentially expressed sST2. Then, we investigated the role of sST2 in orthotopic tumor growth of sST2-expressing mouse pancreatic cancer Panc02 cells in immunocompetent mice. shRNA-mediated knockdown of sST2 expression in the cells suppressed orthotopic tumor growth, which was partially recovered by overexpression of shRNA-resistant sST2 mRNA but was not evident in IL-33 knockout mice. This was associated with decreases in Cxcl3 expression, vessel density and accumulation of cancer-associated neutrophils but not cancer-associated macrophages. Administration of SB225002, an inhibitor of the CXCL3 receptor CXCR2, induced similar effects. Cancer cell-derived sST2 enhances tumor growth through upregulation of CXCL3 via inhibition of IL-33-ST2L signaling in the tumor microenvironment of pancreatic cancer. These results suggest that the sST2 and the CXCL3-CXCR2 axis could be therapeutic targets.