Mouse Model Of Carcinoma Research Articles

Pre-clinical lung squamous cell carcinoma mouse models to identify novel biomarkers and therapeutic interventions.

Primary lung carcinoma or lung cancer (LC) is classified into small-cell or non-small-cell (NSCLC) lung carcinoma. Lung squamous cell carcinoma (LSCC) is the second most common subtype of NSCLC responsible for 30% of all LCs, and its survival remains low with only 24% of patients living for five years or longer post-diagnosis primarily due to the advanced stage of tumors at the time of diagnosis. The pathogenesis of LSCC is still poorly understood and has hampered the development of effective diagnostics and therapies. This review highlights the known risk factors, genetic and epigenetic alterations, miRNA biomarkers linked to the development and diagnosis of LSCC and the lack of therapeutic strategies to target specifically LSCC. We will also discuss existing animal models of LSCC including carcinogen induced, transgenic and xenograft mouse models, and their advantages and limitations along with the chemopreventive studies and molecular studies conducted using them. The importance of developing new and improved mouse models will also be discussed that will provide further insights into the initiation and progression of LSCC, and enable the identification of new biomarkers and therapeutic targets.

Accumulation and neuroprotective effects of lithium on hepatocellular carcinoma mice model

AimThe peripheral tumor growth is accompanied by the accumulation of inflammatory mediators in the blood that can negatively influence blood-brain barrier function and neuronal structure and develop the cancer-associated depression. The aim of the study was to evaluate the neurobiological effects of lithium on hepatocellular carcinoma mice model. MethodsIn this study we analyzed the locomotor activity of lithium-treated tumor-bearing mice using the Phenomaster instrument. Inductively coupled plasma mass-spectral analysis was used to determine lithium levels in blood, brain, liver, kidneys, tumors and muscle tissues. The prefrontal cortex neurons ultrastructure was assessed by transmission electron microscopy. Expression of BDNF, GRP78, EEA1, LAMP1, and LC3 beta in neurons was determined by immunohistochemical analysis. ResultsA decrease in locomotor activity was found in animals with tumors. At the same time, the low expression levels of the neurotrophic factor BDNF and early endosomal marker EEA1 were revealed, as well as the decreased amount of synaptic vesicles and synapses was shown. Signs of endoplasmic reticulum stress and autophagy development in neurons of animals with tumors were noted. Lithium carbonate administration had a corrective effect on animal’s behavior and the prefrontal cortex neurons structure. ConclusionsIn summary, lithium can restore the neuronal homeostasis in tumor-bearing mice.

Endothelial cells are a key target of IFN-g during response to combined PD-1/CTLA-4 ICB treatment in a mouse model of bladder cancer

To explore mechanisms of response to combined PD-1/CTLA-4 immune checkpoint blockade (ICB) treatment in individual cell types, we generated scRNA-seq using a mouse model of invasive urothelial carcinoma with three conditions: untreated tumor, treated tumor, and tumor treated after CD4+ Tcell depletion. After classifying tumor cells based on detection of somatic variants and assigning non-tumor cell types using SingleR, we performed differential expression analysis, overrepresentation analysis, and gene set enrichment analysis (GSEA) within each cell type. GSEA revealed that endothelial cells were enriched for upregulated IFN-g response genes when comparing treated cells to both untreated cells and cells treated after CD4+ Tcell depletion. Functional analysis showed that knocking out IFNgR1 in endothelial cells inhibited treatment response. Together, these results indicated that IFN-g signaling in endothelial cells is a key mediator of ICB induced anti-tumor activity.

High-Fat Mouse Model to Explore the Relationship between Abnormal Lipid Metabolism and Enolase in Pancreatic Cancer.

Malignant tumors have become a major social health problem that seriously threatens human health, among which pancreatic cancer has a high degree of malignancy, difficult diagnosis and treatment, short survival time, and high mortality. More and more attention has been paid to abnormal lipid metabolism as a momentous carcinogenesis mechanism. Here, we explored the relationship between abnormal lipid metabolism, enolase, and pancreatic cancer by clinical data analysis. A high-fat mouse model was constructed, and then, a subcutaneous tumorigenesis mouse model of carcinoma of pancreatic cells and a metastatic neoplasm mouse pattern of pancreatic carcinoma cells injected through the tail vein were constructed to explore whether abnormal lipid metabolism affects the progression of pancreatic cancer in mice. We constructed a high-lipid model of pancreatic carcinoma cell lines and knockdown and overexpressed enolase in pancreatic carcinoma cell lines and investigated whether high lipid regulates epithelial-mesenchymal transition (EMT) by upregulating enolase (ENO), thereby promoting the cells of pancreatic carcinoma to invade and migrate. Triglycerides, total cholesterol, free cholesterin, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and neuron-specific enolase (NSE) from pancreatic cancer patients and nonpancreatic cancer patients were tested. The differences in blood lipids between patients with and without pancreatic carcinoma were compared, and the correlation between blood lipids and neuron-specific enolase was analyzed. We confirmed that the serum triglyceride level of pancreatic cancer patients at initial diagnosis is overtopping nonpancreatic cancer patients, and the neuron-specific enolase level of patients with pancreatic carcinoma is better than nonpancreatic carcinoma sufferers. Triglyceride level is positively correlated with neuron-specific enolase level, and serum triglyceride level has predictive value for pancreatic cancer. Hyperlipidemia can promote tumor growth and increase the expression levels of ENO1, ENO2, and ENO3 in subcutaneous tumor formation of pancreatic cancer in mice. Additional hyperlipidemia promoted pancreatic carcinoma metastasis in the lung in mice injected through the tail vein, which confirmed that hyperlipidemia accelerated the process of EMT by increasing the expression of ENO1, ENO2, and ENO3, therefore promoting the pancreatic cancer cell metastasis.

Genomic and Transcriptomic Landscape of an Oral Squamous Cell Carcinoma Mouse Model for Immunotherapy.

The immune checkpoint inhibitor (ICI), anti-programmed death-1 (anti-PD-1), has shown moderate efficacy in some patients with head and neck squamous cell carcinoma (HNSCC). Because of this, it is imperative to establish a mouse tumor model to explore mechanisms of antitumor immunity and to develop novel therapeutic options. Here, we examined the 4-nitroquinoline-1-oxide (4NQO)-induced oral squamous cell carcinoma (OSCC) model for genetic aberrations, transcriptomic profiles, and immune cell composition at different pathologic stages. Genomic exome analysis in OSCC-bearing mice showed conservation of critical mutations found in human HNSCC. Transcriptomic data revealed that a key signature comprised of immune-related genes was increased beginning at the moderate dysplasia stages. We first identified that macrophage composition in primary tumors differed across pathologic stages, leading to an oncogenic evolution through a change in the M1/M2 macrophage ratio during tumorigenesis. We treated the 4NQO-induced OSCC-bearing mice with anti-PD-1 and agonistic anti-CD40, which modulated multiple immune responses. The growth of tumor cells was significantly decreased by agonistic anti-CD40 by promoting an increase in the M1/M2 ratio. By examining cross-species genomic conservation in human and mouse tumors, our study demonstrates the molecular mechanisms underlying the development of OSCC and the regulation of contributing immune-related factors, and aims to facilitate the development of suitable ICI-based treatments for patients with HNSCC.

MitoQ combats tumor cell progression in Ehrlich ascites carcinoma mice: A crosstalk between mitochondrial oxidative status, mitophagy, and NF-κB signaling

Despite the clinical advances in cancer treatment, the high mortality rate is still a great challenge, requiring much effort to find new and efficient cancer therapies. AimsThe present evidence investigated the potential antiproliferative impact of the mitochondrial-targeted antioxidant, Mitoquinol (MitoQ), on a mouse model of Ehrlich ascites carcinoma (EAC). Main methodsMice-bearing tumors were administered two doses of MitoQ (0.3 mg & 0.5 mg/kg; i.p daily) or doxorubicin (2 mg/kg; i.p daily) for 20 days. Key findingsEAC mice revealed exacerbated mitochondrial reactive oxygen species (mtROS) and impaired mitochondrial membrane potential (△Ψm). Dysfunctional mitophagy was observed in EAC mice, along with boosting aerobic glycolysis. In addition, tumor cells exhibited higher proliferation rates, thereby stimulating cell cycle, invasion, and angiogenesis biomarkers together with suppressing proapoptotic proteins, events that might be correlated with activation of NF-κB signaling. The administration of MitoQ combated tumor cell survival and dissemination in EAC mice as evidenced by reducing tumor volumes and weights and increasing the number of necrotic areas in histopathological assessment. MitoQ also repressed tumor cell cycle, invasion, and angiogenesis via preventing cyclin D1 mRNA, MMP-1, and CD34 levels as well as VEGF protein expression. These observations were associated with the abrogation of mtROS overproduction and enhancement of the mitophagy proteins, PINK1/Parkin levels, followed by inhibition of NADH dehydrogenase. Notably, NF-κB signaling was modulated. SignificanceThis study suggests that MitoQ combated tumor cell survival and progression in EAC mice by maintaining mtROS and restoring mitophagy, thereby attenuation of NF-κB activation.

ANGPTL2-mediated epigenetic repression of MHC-I in tumor cells accelerates tumor immune evasion.

Loss or downregulation of major histocompatibility complex class I (MHC-I) contributes to tumor immune evasion. We previously demonstrated that angiopoietin-like protein 2 (ANGPTL2) promotes tumor progression using a Xp11.2 translocation renal cell carcinoma (tRCC) mouse model. However, molecular mechanisms underlying ANGPTL2 tumor-promoting activity in the tRCC model remained unclear. Here, we report that ANGPTL2 deficiency in renal tubular epithelial cells slows tumor progression in the tRCC mouse model and promotes activated CD8+ T-cell infiltration of kidney tissues. We also found that Angptl2-deficient tumor cells show enhanced interferon γ-induced expression of MHC-I and increased susceptibility to CD8+ T-cell-mediated anti-tumor immune responses. Moreover, we provide evidence that the ANGPTL2-α5β1 integrin pathway accelerates polycomb repressive complex 2-mediated repression of MHC-I expression in tumor cells. These findings suggest that ANGPTL2 signaling in tumor cells contributes to tumor immune evasion and that suppressing that signaling in tumor cells could serve as a potential strategy to facilitate tumor elimination by T-cell-mediated anti-tumor immunity.

Pharmacological targeting of netrin-1 inhibits EMT in cancer.

Epithelial-to-mesenchymal transition (EMT) regulates tumour initiation, progression, metastasis and resistance to anti-cancer therapy1-7. Although great progress has been made in understanding the role of EMT and its regulatory mechanisms in cancer, no therapeutic strategy to pharmacologically target EMT has been identified. Here we found that netrin-1 is upregulated in a primary mouse model of skin squamous cell carcinoma (SCC) exhibiting spontaneous EMT. Pharmacological inhibition of netrin-1 by administration of NP137, a netrin-1-blocking monoclonal antibody currently used in clinical trials in human cancer (ClinicalTrials.gov identifier NCT02977195 ), decreased the proportion of EMT tumour cells in skin SCC, decreased the number of metastases and increased the sensitivity of tumour cells to chemotherapy. Single-cell RNA sequencing revealed the presence of different EMT states, including epithelial, early and late hybrid EMT, and full EMT states, in control SCC. By contrast, administration of NP137 prevented the progression of cancer cells towards a late EMT state and sustained tumour epithelial states. Short hairpin RNA knockdown of netrin-1 and its receptor UNC5B in EPCAM+ tumour cells inhibited EMT in vitro in the absence of stromal cells and regulated a common gene signature that promotes tumour epithelial state and restricts EMT. To assess the relevance of these findings to human cancers, we treated mice transplanted with the A549 human cancer cell line-which undergoes EMT following TGFβ1 administration8,9-with NP137. Netrin-1 inhibition decreased EMT in these transplanted A549 cells. Together, our results identify a pharmacological strategy for targeting EMT in cancer, opening up novel therapeutic interventions for anti-cancer therapy.

The effect of m2 peptide targeted nanoliposomes containing crocin on induction of phenotypic change in tumor macrophages to M1 state

AimsCrocin has immunomodulatory and anticancer effects. In this study, crocin was used to induce the M1 phenotype in mouse tumor macrophages. Main methodsA targeted liposomal formulation with m2 peptide was prepared and characterized to deliver crocin to the M2 macrophages present in the tumor environment. RT-qPCR and IHC were performed for in vitro and in vivo (in C26 colon carcinoma mouse model at a dose of 50 mg/kg) assessment of M1 induction, respectively. Key findingsIn vitro results indicated that liposome modified with m2 peptide was non-toxic to macrophages and had an improved uptake by macrophages compared to the non-targeted formulation and induced M1 phenotype through an IL6-independent pathway. M2 peptide- modified liposome showed considerable tumor accumulation and anti-tumor effects and significantly shifted the phenotype of tumor macrophages towards an anti-tumor M1 phenotype. SignificanceProbably the remarkable anti-tumor responses observed in this study with m2 peptide-targeted liposomal formulations containing crocin were due to the enhanced delivery of crocin to the tumor macrophage and the subsequent initiation of anti-tumor immune responses.

Brief Report: Acetaminophen Reduces Neoadjuvant Chemoimmunotherapy Efficacy in Patients With NSCLC by Promoting Neutrophil Extracellular Trap Formation: Analysis From a Phase 2 Clinical Trial

IntroductionNeoadjuvant chemoimmunotherapy has recently been the standard of care for resectable locally advanced NSCLC. Factors affecting the neoadjuvant immunotherapy efficacy, however, remain elusive. Metabolites have been found to modulate immunity and associate with immunotherapeutic efficacy in advanced tumors. Therefore, we aimed to investigate the impact of plasma metabolites on the pathologic response after neoadjuvant chemoimmunotherapy. MethodsPatients with stage IIIA (N2) NSCLC who underwent neoadjuvant chemoimmunotherapy in a prospective phase 2 clinical trial (NCT04422392) were enrolled. Metabolomic profiling of the plasma before treatment was performed using liquid chromatography–mass spectrometry. A Lewis lung carcinoma mouse model was further used to investigate the underlying mechanisms. Proteomics and multiplexed immunofluorescence of the mice tumor were performed. ResultsA total of 39 patients who underwent three cycles of anti–programmed cell death-protein 1 (anti–PD-1) (sintilimab) and chemotherapy were included. The level of acetaminophen (APAP) was found to be significantly elevated in patients who did not achieve major pathologic response. The level of APAP remained an independent predictor for major pathologic response in multivariate logistic analysis. In the Lewis lung carcinoma mouse model, combination of APAP and anti–PD-1 treatment significantly reduced the treatment efficacy compared with anti–PD-1 treatment alone. Proteomics of the tumor revealed that myeloid leukocyte activation and neutrophil activation pathways were enriched after APAP treatment. Tumor microenvironment featuring analysis also revealed that the combination treatment group was characterized with more abundant neutrophil signature. Further multiplexed immunofluorescence confirmed that more neutrophil extracellular trap formation was observed in the combination treatment group. ConclusionsAPAP could impair neoadjuvant chemoimmunotherapy efficacy in patients with NSCLC by promoting neutrophil activation and neutrophil extracellular trap formation.

Gender Differences in a Mouse Model of Hepatocellular Carcinoma Revealed Using Multi-Modal Imaging.

The worldwide incidence of hepatocellular carcinoma (HCC) continues to rise, in part due to poor diet, limited exercise, and alcohol abuse. Numerous studies have suggested that the loss or mutation of PTEN plays a critical role in HCC tumorigenesis through the activation of the PI3K/Akt signaling axis. The homozygous knockout of PTEN in the livers of mice results in the accumulation of fat (steatosis), inflammation, fibrosis, and eventually progression to HCC. This phenotype bears a striking similarity to non-alcoholic steatohepatitis (NASH) which is thought to occupy an intermediate stage between non-alcoholic fatty liver disease (NAFLD), fibrosis, and HCC. The molecular and physiological phenotypes that manifest during the transition to HCC suggest that molecular imaging could provide a non-invasive screening platform to identify the hallmarks of HCC initiation prior to the presentation of clinical disease. We have carried out longitudinal imaging studies on the liver-specific PTEN knockout mouse model using CT, MRI, and multi-tracer PET to interrogate liver size, steatosis, inflammation, and apoptosis. In male PTEN knockout mice, significant steatosis was observed as early as 3 months using both magnetic resonance spectroscopy (MRS) and computed tomography (CT). Enhanced uptake of the apoptosis tracer 18F-TBD was also observed in the livers of male PTEN homozygous knockout mice between 3 and 4 months of age relative to heterozygous knockout controls. Liver uptake of the inflammation tracer [18F]4FN remained relatively low and constant over 7 months in male PTEN homozygous knockout mice, suggesting the suppression of high-energy ROS/RNS with PTEN deletion relative to heterozygous males where the [18F]4FN liver uptake was elevated at early and late time points. All male PTEN homozygous mice developed HCC lesions by month 10. In contrast to the male cohort, only 20% (2 out of 10) of female PTEN homozygous knockout mice developed HCC lesions by month 10. Steatosis was significantly less pronounced in the female PTEN homozygous knockout mice relative to males and could not accurately predict the eventual occurrence of HCC. As with the males, the [18F]4FN uptake in female PTEN homozygous knockout mice was low and constant throughout the time course. The liver uptake of 18F-TBD at 3 and 4.5 months was higher in the two female PTEN knockout mice that would eventually develop HCC and was the most predictive imaging biomarker for HCC in the female cohort. These studies demonstrate the diagnostic and prognostic role of multi-modal imaging in HCC mouse models and provide compelling evidence that disease progression in the PTEN knockout model is highly dependent on gender.

Single-cell RNA sequencing reveals enhanced antitumor immunity after combined application of PD-1 inhibitor and Shenmai injection in non-small cell lung cancer

BackgroundImmune checkpoint inhibitors (ICIs) have altered the clinical management of non-small cell lung cancer (NSCLC). However, the low response rate, severe immune-related adverse events (irAEs), and hyperprogressive disease following ICIs monotherapy require attention. Combination therapy may overcome these limitations and traditional Chinese medicine with immunomodulatory effects provides a promising approach. Shenmai injection (SMI) is a clinically effective adjuvant treatment for cancer with chemotherapy and radiotherapy. Therefore, the combined effects and mechanisms of SMI and programmed death-1 (PD-1) inhibitor against NSCLC was focused on this study.MethodsA Lewis lung carcinoma mouse model and a lung squamous cell carcinoma humanized mouse model were used to investigate the combined efficacy and safety of SMI and PD-1 inhibitor. The synergistic mechanisms of the combination therapy against NSCLC were explored using single-cell RNA sequencing. Validation experiments were performed using immunofluorescence analysis, in vitro experiment, and bulk transcriptomic datasets.ResultsIn both models, combination therapy alleviated tumor growth and prolonged survival without increasing irAEs. The GZMAhigh and XCL1high natural killer (NK) cell subclusters with cytotoxic and chemokine signatures increased in the combination therapy, while malignant cells from combination therapy were mainly in the apoptotic state, suggesting that mediating tumor cell apoptosis through NK cells is the main synergistic mechanisms of combination therapy. In vitro experiment confirmed that combination therapy increased secretion of Granzyme A by NK cells. Moreover, we discovered that PD-1 inhibitor and SMI combination blocked inhibitory receptors on NK and T cells and restores their antitumoral activity in NSCLC better than PD-1 inhibitor monotherapy, and immune and stromal cells exhibited a decrease of angiogenic features and attenuated cancer metabolism reprogramming in microenvironment of combination therapy.ConclusionsThis study demonstrated that SMI reprograms tumor immune microenvironment mainly by inducing NK cells infiltration and synergizes with PD-1 inhibitor against NSCLC, suggested that targeting NK cells may be an important strategy for combining with ICIs.4EoQVoCxPUSr8SKnFMutzeVideo

Immunotherapy Targeting CCR8+ Regulatory T Cells Induces Antitumor Effects via Dramatic Changes to the Intratumor CD8+ T Cell Profile.

Regulatory T cells (Tregs) contribute to the formation of a tumor-immunosuppressive microenvironment. CCR8 is reportedly selectively expressed in tumor Tregs, and an anti-CCR8 Ab can exert potent antitumor effects by eliminating intratumor Tregs in murine tumor models. In this study, we analyzed changes to intratumor immunity after anti-CCR8 Ab administration, especially in CD8+ T cells, which are involved in cancer cell killing, using the CT26 colorectal carcinoma mouse model. Immunophenotyping of tumor-infiltrating cells by mass cytometry after Ab administration on day 5 of tumor inoculation revealed that CD8+ T cell subsets were dramatically altered in the CCR8 Ab-treated group, with an increase in naive cells and nonexhausted effector cells and a decrease in exhausted cells with high expression levels of TOX. These results were corroborated with flow cytometry analysis. Delayed administration of the anti-CCR8 Ab on day 9 or 12, when the amount of CCR8+ Tregs and CD8+ T cell exhaustion were more progressed, also resulted in a decrease in exhausted CD8+ T cells, leading to tumor regression. Finally, we confirmed that high CCR8+ Treg infiltration was associated with high TOX expression in CD8+ T cells in human cancer patients. In conclusion, administration of an anti-CCR8 Ab can dramatically alter the activation and exhaustion state of intratumor CD8+ T cells, resulting in strong antitumor effects. In cancer patients with an advanced tumor-immunosuppressive environment, CD8+ T cell exhaustion has progressed along with CCR8+ Treg induction. Therefore, targeted depletion of CCR8+ Tregs is expected to be effective in these patients.

Intermittent Fasting Primes the Tumor Microenvironment and Improves Nanomedicine Delivery in Hepatocellular Carcinoma.

Fasting has many health benefits, including reduced chemotherapy toxicity and improved efficacy. It is unclear how fasting affects the tumor microenvironment (TME) and tumor-targeted drug delivery. Here the effects of intermittent (IF) and short-term (STF) fasting are investigated on tumor growth, TME composition, and liposome delivery in allogeneic hepatocellular carcinoma (HCC) mouse models. To this end, mice areinoculated either subcutaneously or intrahepatically with Hep-55.1C cells and subjected to IF for 24 d or to STF for 1 d. IF but not STF significantly slows down tumor growth. IF increases tumor vascularization and decreases collagen density, resulting in improved liposome delivery. In vitro, fasting furthermore promotes the tumor cell uptake of liposomes. These results demonstrate that IF shapes the TME in HCC towards enhanced drug delivery. Finally, when combining IF with liposomal doxorubicin treatment, the antitumor efficacy of nanochemotherapy isfound to be increased, while systemic side effects arereduced. Altogether, thesefindings exemplify that the beneficial effects of fasting on anticancer therapy outcomes go beyond modulating metabolism at the molecular level.

Establishment of image-guided radiotherapy of orthotopic hepatocellular carcinoma mouse model.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Recently, developments in radiotherapy technology have led to radiotherapy becoming one of the main therapeutics of HCC. Therefore, a suitable animal model for radiotherapy of the orthotopic HCC mouse model is urgently needed. In the present study, Hepa1-6 cells were injected into the liver of C57BL/6 mice in situ to mimic the pathological characteristics of the original HCC. Tumor formation was monitored by applying magnetic resonance imaging techniques and verified by H&E histopathological staining, AFP staining, and Ki67 staining. A single dose of 10 Gy X-ray was applied to simulate clinical radiotherapy plans using image-guided radiotherapy (IGRT) equipment. The efficiency of radiotherapy was then assessed by examining tumor size and weight one week after radiation. Cleaved-caspase3 staining and TUNEL were used to assess apoptosis in tumor tissues. Intrahepatic tumor development was detected in the liver according using MRI. A high-density shadow could be seen 10 days after cell injection, which indicated the formation of HCC in vivo. The tumors grew steadily bigger, and underwent precision radiotherapy 20 days after injection. The typical pathological characteristics of HCC, such as large, deeply stained nuclei and irregular cell size, were visible with H&E staining. After radiotherapy, significantly higher expression of the immunohistochemical markers Ki67 and AFP were detected in tumor tissue than in the nearby normal tissue. Compared with the control group, the tumor volume (p = 0.05) and weight (p < 0.05) of the irradiated group were significantly reduced. In addition, a higher frequency of apoptosis was identified in irradiated HCC tumor tissue using the TUNEL and cleaved-caspase3 staining assay. In a well-established orthotopic HCC model, MRI was utilized to monitor the formation of tumors, and IGRT was used to simulate clinical radiotherapy. The present study could provide a suitable preclinical system for HCC radiotherapy-related studies.

Carbonic Anhydrase IX Targeting Mn(II)-Based Magnetic Resonance Molecular Imaging Probe for Hypoxia Tumors.

Physiological hypoxic conditions in the tumor microenvironment and consequential overexpression of carbonic anhydrase IX (CA IX) are two characteristics shared by numerous types of solid malignant tumors. Early detection with hypoxia assessment is crucial to improve the prognosis and therapy outcomes of hypoxia tumors. Herein, using acetazolamide (AZA) as a CA IX-targeting moiety, we design and synthesize an Mn(II)-based MR imaging probe (named AZA-TA-Mn) incorporating AZA and two Mn(II) chelates of Mn-TyEDTA on a rigid triazine (TA) scaffold. The per Mn relaxivity of AZA-TA-Mn is 2-fold higher than its monomeric Mn-TyEDTA, which allows it for low-dose imaging of hypoxic tumors. In a xenograft mice model of esophageal squamous cell carcinoma (ESCC), a low dosage of AZA-TA-Mn (0.05 mmol/kg) can selectively produce prolonged and stronger contrast enhancement in the tumor compared to the non-specific Gd-DTPA (0.1 mmol/kg). A competition study of co-injection of free AZA and Mn(II) probes confirms the in vivo tumor selectivity of AZA-TA-Mn, resulting in a more than 2.5-fold decreased tumor-to-muscle contrast-to-noise ratio (ΔCNR) at 60 min post-injection. MR imaging results were further supported by the quantitative analysis of Mn tissue levels, as the co-injection of free AZA resulted in significantly reduced Mn accumulation in tumor tissues. Finally, immunofluorescence staining of tissue sections confirms the positive correlation between the tumor accumulation of AZA-TA-Mn and CA IX overexpression. Hence, using CA IX as the hypoxia biomarker, our results illustrate a practical strategy for the development of novel imaging probes for hypoxic tumors.

SAT-240 - Carbohydrate restriction inhibits tumor progression in a hepatocellular carcinoma mouse model

SAT-240 - Carbohydrate restriction inhibits tumor progression in a hepatocellular carcinoma mouse model

Effect of TFF2-MSA on tumor growth and survival in anti-PD-1 treated MC38 and CT26.wt colorectal cancer models by targeting MDSCs.

e15654 Background: Myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment are potential therapeutic targets in immune checkpoint cancer therapy, particularly for cancers that are unresponsive to anti-PD-1 therapy. It has previously been demonstrated that trefoil factor family 2 (TFF2), a secreted anti-inflammatory peptide, can partially suppress MDSC expansion and partially activate tumor immunity through agonism of the CXCR4 receptor. We investigated whether a novel fusion protein, TFF2-murine serum albumin (TFF2-MSA), has single agent activity and can improve on the therapeutic effects of anti-PD-1 in the MC38 and CT26.wt syngeneic mouse models of advanced colorectal cancer (CRC). Methods: Two syngeneic colon carcinoma mouse models were developed using the MC38 and CT26.wt CRC cell lines grafted subcutaneously into C57BL/6 and BALB/C mice, respectively. We generated a recombinant fusion protein, designated TFF2-MSA, which contains murine TFF2 fused to murine serum albumin (MSA), for the purpose of increasing half-life and reducing the frequency of dosing. Mice subsequently received TFF2-MSA, anti-PD-1 antibody (clone 29F.1A12) or combination TFF2-MSA/anti-PD-1. Tumor volume, and survival were measured. At the endpoint, flow cytometry was performed on the draining and axillary lymph nodes, to examine treatment-induced effects on cellular immune profiles. Results: In the MC38 model, on Day 49 of treatment, tumor growth was suppressed (TGI) by TFF2-MSA alone, anti-PD-1 alone, and by combination TFF2-MSA/anti-PD-1 by 50%, 82% and 87% TGI, respectively. The survival rates at 50 days of mice treated with vehicle, TFF2-MSA, anti-PD-1, or combination TFF2-MSA/anti-PD-1 were 20%, 50% and 80%, and 90%, respectively. In the combination TFF2-MSA/anti-PD-1 treated mice, 40% demonstrated a complete response. In the CT26.wt model, tumor growth was suppressed by TFF2-MSA, anti-PD-1 and by combination TFF2-MSA/anti-PD-1 by 17%, 43% and 67%, respectively. Survival in the CT26.wt model at Day 30 treated with vehicle, TFF2-MSA, anti-PD1 and the combination of TFF2-MSA/anti-PD-1 was 0%, 40%, 60% and 60%, respectively. The percentage of exhausted CD8+ T cells was markedly reduced in the draining lymph node by the combination TFF2-MSA/anti-PD-1 treatment, as measured by flow cytometry using antibodies against LAG3, TIM3, and PD-1. Conclusions: TFF2-MSA has single agent activity and is additive to anti-PD-1 antibody checkpoint inhibition in treating syngeneic mouse models of advanced CRC. In a separate abstract, additive effects between TFF2-MSA and anti-PD-1 antibody were also demonstrated in a separate ACKP (Atp4b-Cre; Cdh1-/-; LSL-KrasG12D; Trp53-/-) gastric cancer model, suggesting combination therapy may also be applicable to gastric cancer.

Eicosapentaenoic Acid-Enriched Phospholipids Alleviate Skeletal Muscle Atrophy in Lewis Lung Carcinoma Mouse Model.

Skeletal muscle atrophy is a critical feature of cancer-associated cachexia (CAC) and it is responsible for poor quality of life and high mortality in cancer patients. The previous study demonstrates that eicosapentaenoic acid-enriched phospholipids (EPA-PL) prevent body weight loss in a mouse model of CAC. However, the role of EPA-PL on cancer-induced skeletal muscle atrophy remains unclear. In the present study, a Lewis lung carcinoma (LLC) mouse model is established, then the effect and underlying mechanism of EPA-PL on skeletal muscle atrophy in LLC-bearing mice are investigated. The results reveal that EPA-PL treatment significantly attenuates skeletal muscle atrophy in LLC-bearing mice, as evidenced by suppressing the reductions of skeletal muscle mass, myofiber cross-sectional area, and grip strength. Besides, the study finds that EPA-PL alleviated cancer-induced skeletal muscle atrophy via balancing muscle protein degradation and synthesis, inhibiting type I oxidative muscle fibers atrophy, and promoting mitochondrial function. Furthermore, the results also indicate that EPA-PL may counteract skeletal muscle atrophy in LLC mouse model via a sirtuin 1-dependent mechanism. These findings provide evidence that EPA-PL may be beneficial as a nutritional supplement for prevention and treatment of cancer-induced skeletal muscle atrophy.

Cantharidin suppresses hepatocellular carcinoma development by regulating EZH2/H3K27me3-dependent cell cycle progression and antitumour immune response

BackgroundCantharidin (CTD) is a major ingredient of cantharis (Mylabris phalerata Pallas) and has been used extensively in traditional Chinese medicines. It has been shown to exhibit anticancer activity in multiple types of cancer, especially hepatocellular carcinoma (HCC). However, there is no systematic study on the relationships among the regulatory networks of its targets in HCC therapy. We focused on histone epigenetic regulation and the influence of CTD on the immune response in HCC.MethodsWe performed a comprehensive analysis of novel CTD targets in HCC based on network pharmacology and RNA-seq approaches. The mRNA levels of target genes were analyzed by qRT-PCR, and the corresponding protein levels were confirmed using enzyme-linked immunosorbent assay (ELISA) and immunohistochemical staining (IHC). ChIP-seq data were visualized by IGV software. The associations of gene transcript levels with the cancer immune score and infiltration level were investigated using TIMER. In vivo, the H22 mouse model of hepatocellular carcinoma was established by treatment with CTD and 5-Fu. The immune cell proportions in the blood were elevated in model mice, as shown by flow cytometry.ResultsWe identified 58 targets of CTD, which were involved in various pathways in cancer, including apoptosis, the cell cycle, EMT and immune pathways. Moreover, we found that 100 EMT-related genes were differentially expressed after CTD treatment in HCC cells. Interestingly, our results confirmed that the EZH2/H3K27me3 -related cell cycle pathway is a therapeutic target of CTD in antitumour. In addition, we evaluated the influence of CTD on the immune response. Our data showed that the significantly enriched gene sets were positively correlated with the chemokine biosynthetic and chemokine metabolic modules. The proportions of CD4+/CD8 + T cells and B cells were increased, but the proportion of Tregs was decreased after treatment with CTD in vivo. Moreover, we found that the expression of the inflammatory factor and immune checkpoint genes PD­1/PD-L1 was significantly reduced in the mouse model.ConclusionWe performed a novel integrated analysis of the potential role of CTD in HCC treatment. Our results provide innovative insight into the mechanism by which cantharidin exerts antitumour effects by regulating target genes expression to mediate apoptosis, EMT, cell cycle progression and the immune response in HCC. Based on the effect of CTD on the immune response, it can be used as a potential effective drug to activate antitumour immunity for the treatment of liver cancer.