Mouse Model Of Metastatic Cancer Research Articles

Abstract 6429: A surrogate to the anti-IL1RAP antibody nadunolimab induces tumor microenvironment changes to the metastatic lung and reduces metastatic lesions in mouse models of metastatic cancer

Abstract Interleukin-1 Receptor Accessory Protein (IL1RAP) is a coreceptor for the IL-1 receptor (IL1R1) and is required for IL-1α and IL-1β signaling. IL1RAP is expressed in the tumor microenvironment (TME); on cancer cells, stromal cells and on infiltrating immune cells in several types of cancers, including non-small cell lung cancer (NSCLC), pancreatic cancer (PDAC), triple-negative breast cancer (TNBC) and in metastatic lesions. Nadunolimab (CAN04) is a fully humanized ADCC-enhanced IgG1 antibody targeting IL1RAP and blocking both IL-1α and IL-1β signaling, currently evaluated in combination with chemotherapy in phase I/II clinical trials in NSCLC and PDAC (NCT03267316) and in TNBC (NCT05181462). Interim efficacy data are available for PDAC and NSCLC and are stronger than expected from chemotherapy alone based on historical controls; in a total of 73 PDAC patients, median iPFS is 7.2 months and median OS 12.7 months, while in a total of 30 NSCLC patients, a response rate of 53% is achieved, resulting in median PFS of 6.8 months. Microenvironmental IL1RAP-dependent IL-1 signaling contributes to tumorigenesis, tumor invasiveness and an immune-suppressive TME, partly driven by infiltration and induction of myeloid-derived suppressor cells (MDSCs). We have thus used the MDSC-rich 4T1 murine mammary tumor TNBC model to study metastatic lesions and TME modulation in 4T1 metastatic lungs upon treatment with a mouse surrogate antibody to nadunolimab. Infiltration of gMDSC/Ly6G+ cells was very prominent in metastatic lungs from mice with orthotopically implanted 4T1 breast cancer cells compared to lungs from naive mice. Interestingly, infiltrating Ly6G+ cells from metastatic lungs had a distinctly upregulated IL1RAP expression compared to Ly6G+ cells from naïve lungs. Treatment with the nadunolimab surrogate antibody significantly reduced the number of lung metastases and induced prominent changes in the lung microenvironment where nanostring analysis showed global changes in adhesion and migration-related genes, as well as genes associated with cell activation. The effect on metastasis was not confined to the 4T1 model since a reduction of metastatic tumor cells after treatment with the mouse surrogate antibody was also observed in the murine B16-F10-luc i.v. model. Together these data indicate that targeting IL1RAP is an effective way to modulate the TME and counteract the suppressive environment in metastatic tissue, and ultimately may reduce the potential for metastatic tumors in cancer patients. Citation Format: Elin Jaensson Gyllenbäck, Camilla Rydberg Millrud, Petter Skoog, Caitríona Grönberg, David Liberg. A surrogate to the anti-IL1RAP antibody nadunolimab induces tumor microenvironment changes to the metastatic lung and reduces metastatic lesions in mouse models of metastatic cancer. [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 6429.

Development of Preclinical Ultrasound Imaging Techniques to Identify and Image Sentinel Lymph Nodes in a Cancerous Animal Model.

Simple SummaryBowel cancer is the fourth most common cancer in the UK. Treatment is dominated by major surgery because current imaging modalities cannot accurately determine lymph node involvement or vascular invasion. Although potentially curative, surgery carries a high risk of short- and long-term morbidity, including stoma formation. Optimized pre-treatment imaging would decrease the number of bowel cancer patients requiring major surgery. Such imaging would also be equally applicable to other cancers where local resection could significantly improve patient quality of life without compromising long-term outcomes (e.g., melanoma, head and neck cancers, gastro-esophageal, bladder). In this study, we created two mouse models (tumor and control) and used the resolution of high-frequency ultrasound imaging and parameters calculated from dynamically contrast-enhanced ultrasound to predict the likelihood of draining lymph nodes to be involved in the disease.Lymph nodes (LNs) are believed to be the first organs targeted by colorectal cancer cells detached from a primary solid tumor because of their role in draining interstitial fluids. Better detection and assessment of these organs have the potential to help clinicians in stratification and designing optimal design of oncological treatments for each patient. Whilst highly valuable for the detection of primary tumors, CT and MRI remain limited for the characterization of LNs. B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) can improve the detection of LNs and could provide critical complementary information to MRI and CT scans; however, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines advise that further evidence is required before US or CEUS can be recommended for clinical use. Moreover, knowledge of the lymphatic system and LNs is relatively limited, especially in preclinical models. In this pilot study, we have created a mouse model of metastatic cancer and utilized 3D high-frequency ultrasound to assess the volume, shape, and absence of hilum, along with CEUS to assess the flow dynamics of tumor-free and tumor-bearing LNs in vivo. The aforementioned parameters were used to create a scoring system to predict the likelihood of a disease-involved LN before establishing post-mortem diagnosis with histopathology. Preliminary results suggest that a sum score of parameters may provide a more accurate diagnosis than the LN size, the single parameter currently used to predict the involvement of an LN in disease.

Abstract 623: Investigating potential off-target effects of the dual Rac and Cdc42 inhibitor MBQ-167

Abstract Metastasis is a major cause of death in epithelial cancers, largely because of a lack of effective treatments. The metastatic inhibitor MBQ-167 was developed to target the Rho GTPases Rac and Cdc42, which promote cell cycle progression, proliferation, survival, migration/invasion, and thus, metastasis. Our published data show that MBQ-167 inhibits the activation of Rac and Cdc42 with ~100 nM IC50, and subsequently inhibits their effector p21-activated kinase (PAK) activation by autophosphorylation. In metastatic cancer cells, MBQ-167 induces a loss of cell polarity, followed by detachment from the substrate, and subsequent apoptosis (anoikis). The objective herein was to determine the potential off-target effects of MBQ-167. Therefore, the effect of MBQ-167 on the triple negative breast cancer kinome was investigated using a Human Phospho-Kinase Array for 45 phospho proteins. MDA-MB-231 cells treated with MBQ-167 for 24 h at 200 nM demonstrated no difference in phosphorylation of off-target kinases. However, phospho (p)-CREB and p-c-Jun transcription factor levels increased by ~3-fold in the cells that remained attached following MBQ-167 treatment. This was confirmed by Western blot for p-CREB and p-c-Jun as well as their transcriptional targets (Cyclin D1, survivin, ZEB1). However, a time-course analysis via Western blot revealed that this increase in CREB and c-Jun activity is transient. Western blotting of the attached and detached cell populations of MDA-MB-231 cells following MBQ-167 treatment for 24, 48, or 96 h demonstrated decreased c-Jun/p-c-jun, and CREB and Jun targets in the detached cell population. Moreover, the detached cells demonstrated additional decreases in phospho forms of ERK1/2, Akt, mTOR, beta catenin and STAT3, which have all been implicated in Rac/PAK signaling; as well as reduced expression of the anti-apoptotic proteins Bcl2, BCL-XL, and MCl-1. Therefore, we posit that the initial upregulation of transcription factors in response to MBQ-167 is a transient reaction to its strong Rac/Cdc42/PAK inhibition. Prolonged treatment with MBQ-167 causes a massive deregulation of cancer drivers and pro-survival proteins to ultimately result in anoikis. We attempted to create a MBQ-167 resistant cell population by treating MDA-MB-231 cells with ascending concentrations of MBQ-167 over time, but were unable to recover any live cells. Therefore, we conclude that MBQ-167 is a direct and specific inhibitor of Rac and Cdc42 and that potential off-target effects of MBQ-167 are only temporary, where 100% of the metastatic cancer cells treated with MBQ-167 ultimately undergo apoptosis. Collectively, our data on the mechanism of action of MBQ-167 and its efficacy in vitro and in vivo in mouse models of metastatic cancer demonstrate that MBQ-167 is a viable anti-metastatic cancer inhibitor for further development as an experimental therapeutic. Citation Format: Hector M. Picon, Maria Del Mar Maldonado, Surangani F. Dharmawardhane Flanagan. Investigating potential off-target effects of the dual Rac and Cdc42 inhibitor MBQ-167 [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 623.

Small-molecule targeted recruitment of a nuclease to cleave an oncogenic RNA in a mouse model of metastatic cancer

As the area of small molecules interacting with RNA advances, general routes to provide bioactive compounds are needed as ligands can bind RNA avidly to sites that will not affect function. Small-molecule targeted RNA degradation will thus provide a general route to affect RNA biology. A non-oligonucleotide-containing compound was designed from sequence to target the precursor to oncogenic microRNA-21 (pre-miR-21) for enzymatic destruction with selectivity that can exceed that for protein-targeted medicines. The compound specifically binds the target and contains a heterocycle that recruits and activates a ribonuclease to pre-miR-21 to substoichiometrically effect its cleavage and subsequently impede metastasis of breast cancer to lung in a mouse model. Transcriptomic and proteomic analyses demonstrate that the compound is potent and selective, specifically modulating oncogenic pathways. Thus, small molecules can be designed from sequence to have all of the functional repertoire of oligonucleotides, including inducing enzymatic degradation, and to selectively and potently modulate RNA function in vivo.

PC-2 A liposomal formulation of HIF-1α inhibitor echinomycin inhibits growth and metastasis of experimental model of breast cancer

PC-2 A liposomal formulation of HIF-1α inhibitor echinomycin inhibits growth and metastasis of experimental model of breast cancer

The Selective Tie2 Inhibitor Rebastinib Blocks Recruitment and Function of Tie2Hi Macrophages in Breast Cancer and Pancreatic Neuroendocrine Tumors.

Tumor-infiltrating myeloid cells promote tumor progression by mediating angiogenesis, tumor cell intravasation, and metastasis, which can offset the effects of chemotherapy, radiation, and antiangiogenic therapy. Here, we show that the kinase switch control inhibitor rebastinib inhibits Tie2, a tyrosine kinase receptor expressed on endothelial cells and protumoral Tie2-expressing macrophages in mouse models of metastatic cancer. Rebastinib reduces tumor growth and metastasis in an orthotopic mouse model of metastatic mammary carcinoma through reduction of Tie2+ myeloid cell infiltration, antiangiogenic effects, and blockade of tumor cell intravasation mediated by perivascular Tie2Hi/Vegf-AHi macrophages in the tumor microenvironment of metastasis (TMEM). The antitumor effects of rebastinib enhance the efficacy of microtubule inhibiting chemotherapeutic agents, either eribulin or paclitaxel, by reducing tumor volume, metastasis, and improving overall survival. Rebastinib inhibition of angiopoietin/Tie2 signaling impairs multiple pathways in tumor progression mediated by protumoral Tie2+ macrophages, including TMEM-dependent dissemination and angiopoietin/Tie2-dependent angiogenesis. Rebastinib is a promising therapy for achieving Tie2 inhibition in cancer patients. Mol Cancer Ther; 16(11); 2486-501. ©2017 AACR.

Ketogenic Therapies on Cancer Cachexia in a Mouse Model of Metastatic Cancer

While most cancer deaths are a result of metastatic disease, 20% directly result from cachexia. Cancer cachexia is characterized by the loss of skeletal muscle mass, with or without fat loss, that cannot be fully reversed by conventional nutritional support and results in progressive functional impairment. There are many models of cancer cachexia, but none are ideal as they do not address all aspects of this multifaceted syndrome. The VM‐M3 model is a syngeneic mouse model derived from a spontaneous brain tumor which, when implanted subcutaneously, results in rapid and systemic metastasis throughout the body, including to the liver, lungs, brain, kidneys, and spleen. Male and female VM‐M3 mice were assessed for cancer cachexia phenotype. Tumor progression, organ metastasis, skeletal muscle and adipose tissue recomposition, systemic inflammation, anorexia, albumin, blood urea nitrogen, and other clinical metabolites were evaluated. VM‐M3 male and female models both present rapid systemic metastasis (31 and 32‐day mean survival) with similar progressive increases in primary tumor weight in males and females, respectively. A progressive decrease in calf skeletal muscle weight was seen from week 2 (10% and 12% reduction) to end of life (19% and 23%), with a 40% and 26% reduction in quadriceps weight at end of life for males and females, respectively. Intraperitoneal white adipose tissue displayed progressive wasting with a 20% reduction for both male and females at week 2 and an 82% and 100% reduction for male and females, respectively. Prolonged systemic inflammation was identified via elevated spleen weight (9‐ and 10‐fold increase, respectively), elevated white blood cells counts, and elevated TNF‐α and IL‐6 at week 2 and end of life. Male and female VM‐M3 mice also presented anorexia, hypoalbumin, elevated blood urea nitrogen, and reduced total protein. Dietary interventions were developed to treat this multifaceted model of metastasis induced cancer cachexia. Ketogenic diet and synthetic ketogenic agents (R,S 1,3‐butanediol acetoacetate diester) were administered via diet to determine their ability to attenuate cachexic phenotype (altered tumor progression, skeletal muscle, adipose tissue, systemic inflammation, and additional cachexic biomarkers).Support or Funding InformationScivation Inc.

Abstract 4109: Unbiased detection of disseminated tumor cells in murine bone marrow

Abstract Approximately 20-30% of prostate cancer patients develop disease recurrence and metastasis years after initial therapy. This is thought to be largely due to the presence of growth-arrested and chemoresistant disseminated tumor cells (DTCs) in secondary sites, such as bone. Bone metastasis is found in 90-100% of prostate cancer patients who succumb to the disease. There are still many gaps in knowledge about the biological mechanisms by which DTCs home to bone, resist chemotherapy, become dormant, and escape dormancy to grow into clinical metastases. As such, it is important to be able to detect, quantify, and study bone marrow DTCs. In particular, it must be possible to do this in metastatic cancer mouse models, which are critical to study the process of tumor dissemination. DTC detection techniques currently exist, usually as either a positive selection or negative selection methodology. Positive selection techniques use markers or cell size to isolate and purify tumor cells out of the bone marrow. Positive selection markers are generally epithelial-specific, such as EpCam, E-cadherin, or Cytokeratin, and therefore may miss cells that lose epithelial marker expression and may gain mesenchymal markers. DTCs can also be as small as or smaller than white blood cells, meaning that positive selection based on size may miss some DTCs. Negative selection enriches for DTCs by removing blood and bone marrow cells from the population, usually using cell-specific markers. A popular strategy is CD45-based depletion, which removes white blood cells, and theoretically leaves behind DTCs. In our hands, this strategy causes loss of DTCs in the depletion process. To capture these heterogeneous and rare DTCs, we have developed a strategy to detect DTCs in murine bone marrow in an un-biased manner. The procedure entails removal of the bone marrow via centrifugation from the long bones (femur and tibia) of mice that have been injected with cancer cells (the injection site may vary depending on the experimental setup). The bone marrow then undergoes red blood cell lysis, and further centrifugation. The white blood cells are then counted, and the bone marrow is spread onto glass slides. The cells on the slide are fixed, permeabilized, and stained (immunofluorescence and RNA fluorescent in situ hybridization can be used). The staining can include any type of marker, including epithelial, mesenchymal, disease-specific, species-specific, or other biologically interesting markers, such as cell cycle markers. The unbiased nature of this procedure is based on the lack of positive or negative selection based on cell size or protein expression. Some DTC loss is noted in this protocol, due to the centrifugation and staining steps, but the cell population on the slide should include all DTC types. Notably, this protocol can be used to detect human or mouse cells in the mouse bone marrow and can thus be used in immune-compromise and immune-competent mouse models of metastasis. Citation Format: Kenneth C. Valkenburg, James R. Hernandez, Sarah R. Amend, James E. Verdone, Michael A. Gorin, Kenneth J. Pienta. Unbiased detection of disseminated tumor cells in murine bone marrow. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4109.

Abstract 1159: Ketosis and hyperbaric oxygen elicit potent anti-cancer effects in vitro and in vivo

Abstract The Warburg effect and tumor hypoxia underlie a unique cancer metabolism characterized by glucose dependency and abnormal mitochondrial function. We have previously shown that this phenotype can be exploited therapeutically by glucose restriction with the ketogenic diet, dietary ketone supplementation, or hyperbaric oxygen (HBOT). We hypothesized that combining these therapies would be an effective non-toxic treatment regimen, so we tested this combination therapy in the VM-M3 mouse model of metastatic cancer. Treated mice exhibited decreased tumor growth rate, decreased metastatic spread to the lungs, kidneys, spleen, adipose, and liver, decreased liver tumor vascularization, and lived twice as long as controls. To further characterize the effects of these therapies, we measured proliferation, viability, ROS production, and expression of key signaling molecules in VM-M3 cells exposed to the following conditions: high glucose (control; 25mM), low glucose (LG; 3mM), ketone supplementation (βHB; 5mM), hyperbaric oxygen (HBOT; 90 min, 2.5 ATA), or combination therapy (LG+BHB+HBOT). Proliferation of VM-M3 cells was measured with trypan blue hemocytometry and was significantly decreased from controls at 24, 48, 72, and 96 hours. Viability of VM-M3 cells was measured by fluorescence microscopy with calcein and EthD-1 and was decreased by 19.2% in LG, 12.5% in βHB, and 38.2% in LG+βHB+HBOT treated cells compared to control. ROS (superoxide) production was measured by fluorescent microscopy with DHE and was increased by 46% in HBOT and by 48% in LG+βHB+HBOT treated cells. Treatment with βHB significantly decreased expression of HIF-1α and pAkt compared to control as measured with western blot. HBOT also inhibited HIF-1α expression but increased pAkt expression in vitro. This study strongly supports further investigation into mechanisms of action and the use of these metabolic therapies as a potential cancer treatment. Citation Format: Angela Poff, Nathan Ward, Thomas Seyfried, Dominic D'Agostino. Ketosis and hyperbaric oxygen elicit potent anti-cancer effects in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1159. doi:10.1158/1538-7445.AM2015-1159

Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy.

The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies – the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation – could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (βHB), hyperbaric oxygen (HBOT), or combination therapy (LG+βHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers.

Evaluating a Dichloroacetate and Metformin Combination in a Mouse Model of Metastatic Cancer

The increased focus on targeting the glycolytic dependency of cancer cells has yielded a number of new therapeutic options with varying promise. Among the therapies currently being investigated thoroughly are dichloroacetate (DCA) and metformin. These agents have been repurposed from other metabolic disorders because of their activities in altering glucose metabolism. Both have exhibited toxicity against a number of cancers without damaging normal tissue, and are also shown to enhance the efficacy of various chemotherapeutics. DCA, an inhibitor of pyruvate dehydrogenase kinase, promotes glucose oxidation through the activation of pyruvate dehydrogenase and subsequent flux of pyruvate through the TCA cycle. Metformin is shown to indirectly activate AMPK through inhibition of complex I of the mitochondrial respiratory chain. We hypothesize that combining these agents will severely alter energy metabolism in tumor cells, resulting in mitochondrial instability and cancer‐specific cell death. We tested the therapeutic efficacy of DCA and metformin in the VM‐M3 model of metastatic cancer. Dietary administration of 500 mg/kg doses of DCA and metformin significantly increased mean survival time (69%, p<.01 and 58%, p<.05 respectively) over untreated control animals. Tumor volume and metastatic spread were reduced in treated animals compared to controls. In vitro incubation with DCA and metformin resulted in a synergistic reduction of VM‐M3 proliferation and viability (p<.05). These data support the further study of a DCA and metformin combination as a potential metabolic therapy for cancer.

Combination ketogenic diet, ketone supplementation, and hyperbaric oxygen therapy inhibits metastatic spread, slows tumor growth, and increases survival time in mice with metastatic cancer (123.7)

Cancers express an energy metabolism characterized by fermentation in the presence of oxygen (Warburg Effect). Mitochondrial dysfunction forces most cancers to require excess glucose for energy and prevents effective ketone metabolism. Abnormal vasculature creates hypoxia which promotes growth and metastasis by activating HIF‐1, further stimulating glycolysis and enhancing the Warburg Effect. The ketogenic diet (KD) is a high fat, low carbohydrate diet that lowers glucose and elevates ketones and slows cancer progression in vivo. Ketones possess inherent anti‐cancer properties, inhibiting cancer cell proliferation and viability in vitro and prolonging survival in vivo. Hyperbaric oxygen therapy (HBOT) increases oxygenation of the tumor, reversing the cancer promoting effects of hypoxia. We have previously shown that KD + HBOT and ketone supplementation slows cancer progression as stand‐alone therapies. We hypothesized that combining these therapies would be a more effective treatment regimen. We tested this combination therapy in the VM‐M3 mouse model of metastatic cancer. Treated mice exhibited decreased tumor growth and metastatic spread to the lungs, kidneys, spleen, adipose, and liver (p<0.05). Treated mice lived 103% longer than controls (p<001). This study suggests that this combination therapy should be further investigated for potential clinical use.Grant Funding Source: Supported by Office of Naval Research and a charitable donation from Scivation Inc.

The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice with Systemic Metastatic Cancer

IntroductionAbnormal cancer metabolism creates a glycolytic-dependency which can be exploited by lowering glucose availability to the tumor. The ketogenic diet (KD) is a low carbohydrate, high fat diet which decreases blood glucose and elevates blood ketones and has been shown to slow cancer progression in animals and humans. Abnormal tumor vasculature creates hypoxic pockets which promote cancer progression and further increase the glycolytic-dependency of cancers. Hyperbaric oxygen therapy (HBO2T) saturates tumors with oxygen, reversing the cancer promoting effects of tumor hypoxia. Since these non-toxic therapies exploit overlapping metabolic deficiencies of cancer, we tested their combined effects on cancer progression in a natural model of metastatic disease.MethodsWe used the firefly luciferase-tagged VM-M3 mouse model of metastatic cancer to compare tumor progression and survival in mice fed standard or KD ad libitum with or without HBO2T (2.5 ATM absolute, 90 min, 3x/week). Tumor growth was monitored by in vivo bioluminescent imaging.ResultsKD alone significantly decreased blood glucose, slowed tumor growth, and increased mean survival time by 56.7% in mice with systemic metastatic cancer. While HBO2T alone did not influence cancer progression, combining the KD with HBO2T elicited a significant decrease in blood glucose, tumor growth rate, and 77.9% increase in mean survival time compared to controls.ConclusionsKD and HBO2T produce significant anti-cancer effects when combined in a natural model of systemic metastatic cancer. Our evidence suggests that these therapies should be further investigated as potential non-toxic treatments or adjuvant therapies to standard care for patients with systemic metastatic disease.

Supplemental ketone metabolic therapy slows tumor growth and increases survival time in mice with metastatic cancer

Metastasis is responsible for 90% of cancer‐related deaths in the U.S. Failure to test therapies in natural pre‐clinical models of metastasis has prevented the effective translation of treatments from lab to clinic. Metastatic cancer cells are highly glycolytic, requiring a large supply of glucose for energy. Mitochondrial dysfunction prevents cancer from efficiently using ketones for energy. Furthermore, ketones inhibit cancer cell proliferation in vitro. The metabolic deficiencies of cancer can be exploited with a ketogenic diet (KD) which lowers glucose and elevates ketones in the blood, a strategy that slows cancer progression in animals and humans. We hypothesized that elevating blood ketones with supplemental ketone administration (SKA) would inhibit cancer progression and enhance efficacy of the KD. We tested this metabolic therapy in the luciferase‐tagged VM‐M3 mouse model of metastatic cancer which spreads naturally in an immunocompetent host, mimicking the natural metastatic phenotype. Mice were fed either ketogenic or standard diet with supplemental ketones (1,3‐butanediol or ketone ester.) Tumor growth was monitored by in vivo bioluminescent imaging. SKA slowed tumor growth and increased survival time by 34–51% when delivered with standard or ketogenic diet. We propose that SKA could enhance the efficacy of standard care and improve the outcome of patients with advanced metastatic disease.Grant Funding Source: Office of Naval Research

RNA-Based Therapeutics: Ready for Delivery?

Delivery of RNA-based therapeutics to specific tissues for treating a variety of diseases faces many hurdles. But with several clinical trials and a slew of studies in animal models underway, the future of RNA-based therapeutics seems bright.

Visualization of GFP-expressing tumors and metastasis in vivo.

We have developed mouse models of metastatic cancer with genetically fluorescent tumors that can be imaged in fresh tissue, in situ, as well as externally. To achieve this capability, we have transduced the green fluorescent protein (GFP) gene, cloned from the bioluminescent jellyfish Aequorea victoria, into a series of human and rodent cancer cell lines that were selected in vitro to stably express GFP in vivo after transplantation to metastatic rodent models. Techniques were also developed for transduction of tumors by GFP in vivo. With this fluorescent tool, we detected and visualized for the first time tumors and metastasis in fresh viable tissue or in situ in host organs down to the single-cell level. GFP tumors on the colon, prostate, breast, brain, liver, lymph nodes, lung, pancreas, bone, and other organs can also be visualized externally, transcutaneously by quantitative whole-body fluorescence optical imaging. Real-time tumor and metastatic growth and angiogenesis and inhibition by representative drugs can be imaged and quantified for rapid antitumor, antimetastatic, and antiangiogenesis drug screening. The GFP-transfected tumor cells enabled a fundamental advance in the visualization of tumor growth and metastasis in real time in vivo.