Cancer Metastasis In Mice Research Articles

Abstract 4129: Mitochondria-targeted antioxidant MitoQ inhibits human breast cancer metastasis in mice

Abstract In oncology, the occurrence of distant metastases often marks the transition from curative to palliative care. Such outcome is highly predictable for triple-negative and HER2-positive breast cancer patients, even if tumors are detected early, and there is no treatment to prevent metastasis. Here, considering that mitochondria are bioenergetic sensors of the tumor microenvironment, we report in preclinical mouse models that human breast cancer relapse is not a fatality: local recurrence and metastatic dissemination can be prevented by MitoQ, a mitochondria-targeted antioxidant that already underwent Phase I safety and Phase II efficacy trials in humans for pathologies other than cancer. Metastatic prevention was confirmed in the MMTV-PyMT model of spontaneously metastatic mouse breast cancer. After oral delivery, MitoQ was effective at nanomolar concentrations at which nonmalignant cells were spared. In anticipation of future clinical trials, a robust signature of the response to MitoQ was defined, applicable to bulk primary tumor biopsies. Citation Format: Tania Capeloa, Pierre Sonveaux. Mitochondria-targeted antioxidant MitoQ inhibits human breast cancer metastasis in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4129.

Magnetic Resonance Imaging as a Tool for Monitoring Intratibial Growth of Experimental Prostate Cancer Metastases in Mice.

Bone metastases cause morbidity and mortality in several human cancer forms. Experimental models are used to unravel the mechanisms and identify possible treatment targets. The location inside the skeleton complicates accurate assessment. This study evaluates the performance of magnetic resonance imaging (MRI) of prostate cancer tumors growing intratibially in mice. MRI detected intratibial tumor lesions with a sensitivity and specificity of 100% and 89%, respectively, compared to histological evaluation. Location and some phenotypical features could also be readily detected with MRI. Regarding volume estimation, the correlation between MRI and histological assessment was high (p < 0.001, r = 0.936). In conclusion, this study finds MRI to be a reliable tool for in vivo, non-invasive, non-ionizing, real-time monitoring of intratibial tumor growth.

Elevated FBXL6 expression in hepatocytes activates VRK2-transketolase-ROS-mTOR-mediated immune evasion and liver cancer metastasis in mice.

Metastatic hepatocellular carcinoma (HCC) is the most lethal malignancy and lacks effective treatment. FBXL6 is overexpressed in human hepatocellular carcinoma (HCC), but whether this change drives liver tumorigenesis and lung metastasis in vivo remains unknown. In this study, we aimed to identify FBXL6 (F-Box and Leucine Rich Repeat Protein 6) as a key driver of HCC metastasis and to provide a new paradigm for HCC therapy. We found that elevated FBXL6 expression in hepatocytes drove HCC lung metastasis and was a much stronger driver than Kras mutation (KrasG12D/+;Alb-Cre), p53 haploinsufficiency (p53+/-) or Tsc1 loss (Tsc1fl/fl;Alb-Cre). Mechanistically, VRK2 promoted Thr287 phosphorylation of TKT and then recruited FBXL6 to promote TKT ubiquitination and activation. Activated TKT further increased PD-L1 and VRK2 expression via the ROS-mTOR axis, leading to immune evasion and HCC metastasis. Targeting or knockdown of TKT significantly blocked FBXL6-driven immune evasion and HCC metastasis in vitro and in vivo. Notably, the level of active TKT (p-Thr287 TKT) was increased and was positively correlated with the FBXL6 and VRK2 expression levels in HCC patients. Our work provides novel mechanistic insights into FBXL6-driven HCC metastasis and suggests that targeting the TKT-ROS-mTOR-PD-L1/VRK2 axis is a new paradigm for treating patients with metastatic HCC with high FBXL6 expression.

Retracted: The Effect and Related Mechanism of Action of Astragalus Compatible with Curcumin against Colon Cancer Metastasis in Mice.

[This retracts the article DOI: 10.1155/2022/9578307.].

Nanoparticulate Cationic Poly(amino acid)s Block Cancer Metastases by Destructing Neutrophil Extracellular Traps

Cancer metastasis that is resistant to conventional therapies has become a major cause of patient death. Recent reports indicate that the neutrophil extracellular trap (NET) is closely associated with cancer distant metastases, and the cell-free DNA of NETs has been identified as the ligand of the transmembrane protein CCDC25 of cancer cells, acting as a chemokine to induce cancer cell migration to distant organs. In this work, we present the poly(aspartic acid) based-cationic materials to interfere with the interaction between NET-DNA and CCDC25, and furthermore to inhibit NET-DNA-mediated cancer cell chemotaxis and migration. Because of a stronger binding affinity to DNA and favorable retention in the liver, nanoparticulate poly(aspartic acid) derivatives (cANP) efficiently reduce the level of hepatic NET-DNA infiltration, leading to a significant suppression of cancer metastases in mice and several human metastatic models. Moreover, the cANP exhibits no toxicity to organs of animals during the entire treatment. Thus, this work suggests a strategy for controlling cancer metastases, which will benefit patients in clinics.

Chronic Exposure to Low Levels of Parabens Increases Mammary Cancer Growth and Metastasis in Mice.

Methylparaben (MP) and propylparaben (PP) are commonly used as food, cosmetic, and drug preservatives. These parabens are detected in the majority of US women and children, bind and activate estrogen receptors (ER), and stimulate mammary tumor cell growth and invasion in vitro. Hemizygous B6.FVB-Tg (MMTV-PyVT)634Mul/LellJ female mice (n = 20/treatment) were exposed to MP or PP at levels within the US Food and Drug Administration's "human acceptable daily intake." These paraben-exposed mice had increased mammary tumor volume compared with control mice (P < 0.001) and a 28% and 91% increase in the number of pulmonary metastases per week compared with the control mice, respectively (P < 0.0001). MP and PP caused differential expression of 288 and 412 mammary tumor genes, respectively (false discovery rate < 0.05), a subset of which has been associated with human breast cancer metastasis. Molecular docking and luciferase reporter studies affirmed that MP and PP bound and activated human ER, and RNA-sequencing revealed increased ER expression in mammary tumors among paraben-exposed mice. However, ER signaling was not enriched in mammary tumors. Instead, both parabens strongly impaired tumor RNA metabolism (eg, ribosome, spliceosome), as evident from enriched KEGG pathway analysis of differential mammary tumor gene expression common to both paraben treatments (MP, P < 0.001; PP, P < 0.01). Indeed, mammary tumors from PP-exposed mice had an increased retention of introns (P < 0.05). Our data suggest that parabens cause substantial mammary cancer metastasis in mice as a function of their increasing alkyl chain length and highlight the emerging role of aberrant spliceosome activity in breast cancer metastasis.

The quorum sensing peptide EntF* promotes colorectal cancer metastasis in mice: a new factor in the host-microbiome interaction

BackgroundColorectal cancer, one of the most common malignancies worldwide, is associated with a high mortality rate, mainly caused by metastasis. Comparative metagenome-wide association analyses of healthy individuals and cancer patients suggest a role for the human intestinal microbiota in tumor progression. However, the microbial molecules involved in host-microbe communication are largely unknown, with current studies mainly focusing on short-chain fatty acids and amino acid metabolites as potential mediators. Quorum sensing peptides are not yet considered in this context since their presence in vivo and their ability to affect host cells have not been reported so far.ResultsHere, we show that EntF*, a metabolite of the quorum sensing peptide EntF produced by Enterococcus faecium, is naturally present in mice bloodstream. Moreover, by using an orthotopic mouse model, we show that EntF* promotes colorectal cancer metastasis in vivo, with metastatic lesions in liver and lung tissues. In vitro tests suggest that EntF* regulates E-cadherin expression and consequently the epithelial-mesenchymal transition, via the CXCR4 receptor. In addition, alanine-scanning analysis indicates that the first, second, sixth, and tenth amino acid of EntF* are critical for epithelial-mesenchymal transition and tumor metastasis.ConclusionOur work identifies a new class of molecules, quorum sensing peptides, as potential regulators of host-microbe interactions. We prove, for the first time, the presence of a selected quorum sensing peptide metabolite in a mouse model, and we demonstrate its effects on colorectal cancer metastasis. We believe that our work represents a starting point for future investigations on the role of microbiome in colorectal cancer metastasis and for the development of novel bio-therapeutics in other disease areas.

The Effect and Related Mechanism of Action of Astragalus Compatible with Curcumin against Colon Cancer Metastasis in Mice.

Colon cancer (CC) is the third most common tumor worldwide. Colon carcinogenesis is strongly linked to inflammation. The initiation and progression of colon cancer may be influenced by epigenetic processes. Cancer metastasis is a multistep process involving several genes and their products. During tumor metastasis, cancer cells first enhance their proliferative capacity by lowering autophagy and apoptosis, and then, their capacity is stimulated by boosting tumors' ability to take nutrients from the outside via angiogenesis. Traditional treatment focuses on eliminating tumor cells by triggering cell death or activating the immune system, which often results in side effects or chemoresistance recurrence. On the contrary, Chinese medicine theory considers the patient's entire inner system and aids in tumor shrinkage while also taking into account the mouse' general health. Because many Chinese herbal medicines (CHM) are consumed as food, using edible CHMs as a diet resource therapy for colon cancer treatment is a viable option. Two traditional Chinese herbs, Astragalus membranaceus and Curcuma zedoaria, are commonly utilized jointly in colon cancer preventive therapy. As a result, the anticancer effect of astragalus and curcumin (AC) on colon cancer suppression in an 18-week AOM-DSS colon cancer mouse model is investigated in this research. These findings may offer a scientific foundation for investigating colon cancer diagnostic biomarkers and therapeutic application of AC in colon cancer treatment. These studies also highlighted the potential effect and mechanism of AC in the treatment of colon cancer, as well as providing insight into how to effectively use it.

Modeling Human Prostate Cancer Metastasis in Mice via Resection of Subcutaneous Allografts.

The 5-year survival rate for patients diagnosed with distant metastatic prostate cancer in the United States is 30.6%. Therefore, there is a great need to develop in vivo model systems to study prostate cancer metastasis and to test potential therapeutics. Most murine prostate cancer metastatic models involve intracardiac or intraosseous implantation of cancer cells, which bypass the early stages of tumor cell migration and invasion. Herein we provide a detailed protocol for a novel method of resecting subcutaneous prostate cancer allografts in immunocompetent mice to produce spontaneous metastases and describe a pilot study using this method of tumor resection. Intact male FVB/NCrl mice (n = 9) were inoculated subcutaneously with Myc-CaP cells. Tumors were surgically resected, and mice were monitored for tumor recurrence. Animals were euthanized or died, and a full set of tissues was collected for histopathologic examination. Tumors took an average of 44 days (range 23–61) to reach 1.7 cm in any direction. All tumors were resectable, and resection of the tumors increased the study length by 70 days (range 30–121). One mouse was euthanized early of an unrelated cause, and of eight remaining mice, four developed tumor recurrence at the site of resection. One mouse developed bone metastases, one mouse developed metastases to the abdominal cavity, and two mice showed signs of local invasion. This study demonstrates that resection of subcutaneous Myc-CaP cell allografts in mice results in local tumor recurrence and the development of distant metastases, providing a new model system to study prostate cancer metastasis in vivo.

Exclusion of NUMB Exon12 Controls Cancer Cell Migration through Regulation of Notch1-SMAD3 Crosstalk.

NUMB is an endocytic adaptor protein that contains four isoforms (p65, p66, p71 and p72) due to alternative splicing regulation. Here, we show that NUMB exon12 (E12)-skipping isoforms p65/p66 promote epithelial to mesenchymal transition (EMT) and cancer cell migration in vitro, and facilitate cancer metastasis in mice, whereas E12-included p71/p72 isoforms attenuate these effects. Mechanistically, p65/p66 isoforms significantly increase the sorting of Notch1 through early endosomes (EEs) for enhanced Notch1 activity. In contrast, p71/p72 isoforms act as negative regulators of Notch1 by ubiquitylating the Notch1 intracellular domain (N1ICD) and promoting its degradation. Moreover, we observed that the interaction between N1ICD and SMAD3 is important for their own stabilization, and for NUMB-mediated EMT response and cell migration. Either N1ICD or SMAD3 overexpression could significantly recuse the migration reduction seen in the p65/p66 knockdown, and Notch1 or SMAD3 knockdown rescued the migration advantage seen in the overexpression of p66. Taken all together, our study provides mechanistic insights into the opposite regulation of Notch1-SMAD3 crosstalk by NUMB isoforms and identifies them as critical regulators of EMT and cancer cell migration.

Cucurbitacin B inhibits TGF-β1-induced epithelial–mesenchymal transition (EMT) in NSCLC through regulating ROS and PI3K/Akt/mTOR pathways

BackgroundLung cancer is the leading cause of cancer mortality worldwide, and most of the patients after treatment with EGF-TKIs develop drug resistance, which is closely correlated with EMT. Cucurbitacin B (CuB) is a natural product of the Chinese herb Cucurbitaceae plant, which has a favorable role in anti-inflammation and anti-cancer activities. However, the effect of CuB on EMT is still far from fully explored. In this study, the inhibition effect of CuB on EMT was investigated.MethodsIn this study, TGF-β1 was used to induce EMT in A549 cells. MTS assay was used to detect the cell viability of CuB co-treated with TGF-β1. Wound healing assay and transwell assay were used to determine the migration and invasion capacity of cells. Flow cytometry and fluorescence microscope were used to detect the ROS level in cells. Western blotting assay and immunofluorescence assay were used to detect the proteins expression. Gefitinib was used to establish EGF-TKI resistant NSCLC cells. B16-F10 intravenous injection mice model was used to evaluate the effect of CuB on lung cancer metastasis in vivo. Caliper IVIS Lumina and HE staining were used to detect the lung cancer metastasis of mice.ResultsIn this study, the results indicated that CuB inhibited TGF-β1-induced EMT in A549 cells through reversing the cell morphology changes of EMT, increasing the protein expression of E-cadherin, decreasing the proteins expression of N-cadherin and Vimentin, suppressing the migration and invasion ability. CuB also decreased the ROS production and p-PI3K, p-Akt and p-mTOR expression in TGF-β1-induced EMT in A549 cells. Furthermore, Gefitinib resistant A549 cells (A549-GR) were well established, which has the EMT characteristics, and CuB could inhibit the EMT in A549-GR cells through ROS and PI3K/Akt/mTOR pathways. In vivo study showed that CuB inhibited the lung cancer metastasis effectively through intratracheal administration.ConclusionCuB inhibits EMT in TGF-β1-induced A549 cells and Gefitinib resistant A549 cells through decreasing ROS production and PI3K/Akt/mTOR signaling pathway. In vivo study validated that CuB inhibits lung cancer metastasis in mice. The study may be supporting CuB as a promising therapeutic agent for NSCLC and Gefitinib resistant NSCLC.

Haploinsufficient tumor suppressor PRP4K is negatively regulated during epithelial-to-mesenchymal transition.

The pre‐mRNA processing factor 4 kinase (PRP4K, also known as PRPF4B) is an essential gene. However, reduced PRP4K expression is associated with aggressive breast and ovarian cancer phenotypes including taxane therapy resistance, increased cell migration and invasion in vitro, and cancer metastasis in mice. These results are consistent with PRP4K being a haploinsufficient tumor suppressor. Increased cell migration and invasion is associated with epithelial‐to‐mesenchymal transition (EMT), but how reduced PRP4K levels affect normal epithelial cell migration or EMT has not been studied. Depletion of PRP4K by small hairpin RNA (shRNA) in non‐transformed mammary epithelial cell lines (MCF10A, HMLE) reduced or had no effect on 2D migration in the scratch assay but resulted in greater invasive potential in 3D transwell assays. Depletion of PRP4K in mesenchymal triple‐negative breast cancer cells (MDA‐MB‐231) resulted in both enhanced 2D migration and 3D invasion, with 3D invasion correlated with higher fibronectin levels in both MDA‐MB‐231 and MCF10A cells and without changes in E‐cadherin. Induction of EMT in MCF10A cells, by treatment with WNT‐5a and TGF‐β1, or depletion of eukaryotic translation initiation factor 3e (eIF3e) by shRNA, resulted in significantly reduced PRP4K expression. Mechanistically, induction of EMT by WNT‐5a/TGF‐β1 reduced PRP4K transcript levels, whereas eIF3e depletion led to reduced PRP4K translation. Finally, reduced PRP4K levels after eIF3e depletion correlated with increased YAP activity and nuclear localization, both of which are reversed by overexpression of exogenous PRP4K. Thus, PRP4K is a haploinsufficient tumor suppressor negatively regulated by EMT, that when depleted in normal mammary cells can increase cell invasion without inducing full EMT.

Gadd45g initiates embryonic stem cell differentiation and inhibits breast cell carcinogenesis

Many self-renewal-promoting factors of embryonic stem cells (ESCs) have been implicated in carcinogenesis, while little known about the genes that direct ESCs exit from pluripotency and regulate tumor development. Here, we show that the transcripts of Gadd45 family genes, including Gadd45a, Gadd45b, and Gadd45g, are gradually increased upon mouse ESC differentiation. Upregulation of Gadd45 members decreases cell proliferation and induces endodermal and trophectodermal lineages. In contrast, knockdown of Gadd45 genes can delay mouse ESC differentiation. Mechanistic studies reveal that Gadd45g activates MAPK signaling by increasing expression levels of the positive modulators of this pathway, such as Csf1r, Igf2, and Fgfr3. Therefore, inhibition of MAPK signaling with a MEK specific inhibitor is capable of eliminating the differentiation phenotype caused by Gadd45g upregulation. Meanwhile, GADD45G functions as a suppressor in human breast cancers. Enforced expression of GADD45G significantly inhibits tumor formation and breast cancer metastasis in mice through limitation of the propagation and invasion of breast cancer cells. These results not only expand our understanding of the regulatory network of ESCs, but also help people better treatment of cancers by manipulating the prodifferentiation candidates.

Blocking Short-Form Ron Eliminates Breast Cancer Metastases through Accumulation of Stem-Like CD4+ T Cells That Subvert Immunosuppression.

The discovery that SF-Ron promotes antitumor immune responses has significant clinical implications. Therapeutic antibodies targeting full-length Ron may not be effective for immunotherapy; poor efficacy of such antibodies in trials may be due to their inability to block SF-Ron. Our data warrant trials with inhibitors targeting SF-Ron in combination with immunotherapy. This article is highlighted in the In This Issue feature, p. 2945.

Fascin Inhibition As a Novel Therapeeutic Strategy in Diffuse Large B-Cell Lymphoma

Fascin is an actin bundling protein used to form cellular projections (e.g. filipodia) involved in cell motility and invasion. Cancer cells often upregulate fascin, and in many cancer types this is associated with poor prognosis, likely due to increased invasive and metastatic potential. We have developed fascin inhibitors that prevent actin bundling and block breast cancer metastasis in mice. Here we explored the potential role of fascin inhibition in lymphoma. We have shown that fascin is upregulated in 44% of canine B-cell (n=62) and 57% of T-cell lymphoma cases (n=28), and that increased fascin expression is correlated with worse overall survival (p=0.03). B-cell lymphoma cases had a median survival time of 388 days while that of T-cell cases was 263 days. We have further shown that a fascin inhibitor, NP-G2-044, kills human and canine diffuse large B-cell lymphoma (DLBCL) cells in vitro, and in vivo in mice bearing canine DLBCL xenografts, with GI50s ranging from 5 to 200uM. Animal toxicology studies (performed by Charles River Laboratories) show no hematologic or other toxicity in dogs and rats at concentrations up to 1,000 mg/kg/day for 28 days; these doses are much higher than the doses needed to achieve concentrations that kill lymphoma in vivo . Therefore, we are planning clinical studies in pet dogs with lymphoma to establish proof of principle prior to a human clinical trial. Collectively, our results demonstrate that fascin is a potential new therapeutic target in DLBCL. DisclosuresHuang:Novita: Equity Ownership, Patents & Royalties: Cornell University and Novita Pharmaceutical has patient on the fascin described here. .

Creatine promotes metastatic dissemination

The molecular regulation of cancer metastasis is not fully understood. In this issue of Cell Metabolism, Zhang etal. (2021) discover that creatine promotes cancer metastasis in mice by promoting activation of the MPS1-Smad2/3 axis.

Activation of TMEM16A Ca2+-activated Cl− channels by ROCK1/moesin promotes breast cancer metastasis

IntroductionTransmembrane protein 16A (TMEM16A) is a Ca2+-activated chloride channel that plays a role in cancer cell proliferation, migration, invasion, and metastasis. However, whether TMEM16A contributes to breast cancer metastasis remains unknown. ObjectiveIn this study, we investigated whether TMEM16A channel activation by ROCK1/moesin promotes breast cancer metastasis. MethodsWound healing assays and transwell migration and invasion assays were performed to study the migration and invasion of MCF-7 and T47D breast cancer cells. Western blotting was performed to evaluate the protein expression, and whole-cell patch clamp recordings were used to record TMEM16A Cl− currents. A mouse model of breast cancer lung metastasis was generated by injecting MCF-7 cells via the tail vein. Metastatic nodules in the lung were assessed by hematoxylin and eosin staining. Lymph node metastasis, overall survival, and metastasis-free survival of breast cancer patients were assessed using immunohistochemistry and The Cancer Genome Atlas dataset. ResultsTMEM16A activation promoted breast cancer cell migration and invasion in vitro as well as breast cancer metastasis in mice. Patients with breast cancer who had higher TMEM16A levels showed greater lymph node metastasis and shorter survival. Mechanistically, TMEM16A promoted migration and invasion by activating EGFR/STAT3/ROCK1 signaling, and the role of the TMEM16A channel activity was important in this respect. ROCK1 activation by RhoA enhanced the TMEM16A channel activity via the phosphorylation of moesin at T558. The cooperative action of TMEM16A and ROCK1 was supported through clinical findings indicating that breast cancer patients with high levels of TMEM16A/ROCK1 expression showed greater lymph node metastasis and poor survival. ConclusionOur findings revealed a novel mechanism underlying TMEM16A-mediated breast cancer metastasis, in which ROCK1 increased TMEM16A channel activity via moesin phosphorylation and the increase in TMEM16A channel activities promoted cell migration and invasion. TMEM16A inhibition may be a novel strategy for treating breast cancer metastasis.

Oligosaccharides from fucosylated glycosaminoglycan prevent breast cancer metastasis in mice by inhibiting heparanase activity and angiogenesis

The invasion and metastasis of tumor cells are the hallmarks of malignant diseases and the greatest obstacle to overcome. Heparanase-mediated degradation of heparan sulfate (HS) is the critical process for tumor angiogenesis and metastasis, therefore, heparanase become an attractive target for cancer research. Herein, we reported a native fucosylated glycosaminoglycan (nHG) extracted from sea cucumber Holothuria fuscopunctata and a depolymerized nHG (dHG) and its contained oligosaccharides (hs17, hs14, hs11, hs8 and hs5), acting as heparanase inhibitors. nHG and its derivatives have the ability to bind with heparanase directly, leading to significant inhibition of heparanase activity. Moreover, their apparent binding affinity to heparanase was comparable to their inhibitory effect, which was elevated along with the increase of chain length, similar to the effect of heparins. In addition, oligosaccharides inhibited the migration and invasion of 4T1 mammary carcinoma cells and human umbilical vein endothelial cells (HUVECs) and also suppressed tube formation in Matrigel matrix and angiogenesis in the chick chorioallantoic membrane (CAM) assay. In the metastatic mouse model, oligosaccharides exhibited practical antimetastatic effects on 4T1 mammary carcinoma cells. According to the reported anticoagulant activity and the low bleeding tendency of dHG and its oligosaccharides, the use of the oligosaccharides may lead to better effects on tumor patients with thrombosis tendency.

Abstract PS17-24: Inhibition of short-form ron eliminates breast cancer metastases through an immune-mediated mechanism

Abstract Metastatic breast cancer is the overwhelming cause of breast cancer mortality and is still incurable. The rapid development of immunotherapy is an exciting new area of research in metastatic breast cancer. However, the extreme immunosuppressive tumor environment poses a major challenge. A better understanding of how the immune system can be harnessed against metastatic cancer is required to improve patient outcomes. We previously showed that expression of the receptor tyrosine kinase Ron in the host, rather than Ron's tumor expression, contributed to tumor-associated immunosuppression and duo inhibition of Ron and CTLA-4 significantly reduced metastatic outgrowth. However, the actual mechanism remains unclear. The present study provides evidence that the N-terminal truncated isoform, short-form Ron (SF-Ron), is the major contributor in suppressing the anti-tumor immune responses and promoting metastatic outgrowth. Genetic deletion of host SF-Ron nearly eliminated breast cancer metastasis in mice, lead to systemic immune-activation, increased recruitment of lymphocytes to the site of metastasis, and augmented tumor-specific T-cell responses. Lack of SF-Ron also leads to the accumulation of CD4+ T-cells in the metastatic lungs and endowed with anti-tumor potential. Importantly, mice treated with small molecule Ron kinase inhibitor that targets both Ron and SF-Ron, produced significantly higher, active, tumor-specific CD8+ T-cells. Our study indicates that blocking Ron, especially the SF-Ron, remodels the metastatic lung microenvironment to enhance anti-tumor immunity. This study sheds light on the potential non-redundant roles of full-length and SF-Ron isoforms in mediating breast cancer metastasis and anti-tumor immune responses; and highlights the relevance of combining Ron inhibitors with immunotherapeutic agents to potentially improve treatment efficacy for metastatic breast cancer patients. Citation Format: Shu-Chin Alicia Lai, Harika Gundlapalli, Huseyin A Ekiz, Alana L Welm. Inhibition of short-form ron eliminates breast cancer metastases through an immune-mediated mechanism [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS17-24.

Rational design of non-toxic GOx-based biocatalytic nanoreactor for multimodal synergistic therapy and tumor metastasis suppression.

Rationale: Glucose oxidase (GOx)-based biocatalytic nanoreactors can cut off the energy supply of tumors for starvation therapy and deoxygenation-activated chemotherapy. However, these nanoreactors, including mesoporous silica, calcium phosphate, metal-organic framework, or polymer nanocarriers, cannot completely block the reaction of GOx with glucose in the blood, inducing systemic toxicity from hydrogen peroxide (H2O2) and anoxia. The low enzyme loading capacity can reduce systemic toxicity but limits its therapeutic effect. Here, we describe a real 'ON/OFF' intelligent nanoreactor with a core-shell structure (GOx + tirazapamine (TPZ))/ZIF-8@ZIF-8 modified with the red cell membrane (GTZ@Z-RBM) for cargo delivery.Methods: GTZ@Z-RBM nanoparticles (NPs) were prepared by the co-precipitation and epitaxial growth process under mild conditions. The core-shell structure loaded with GOx and TPZ was characterized for hydrate particle size and surface charge. The GTZ@Z-RBM NPs morphology, drug, and GOx loading/releasing abilities, system toxicity, multimodal synergistic therapy, and tumor metastasis suppression were investigated. The in vitro and in vivo outcomes of GTZ@Z-RBM NPs were assessed in 4T1 breast cancer cells.Results: GTZ@Z-RBM NPs could spatially isolate the enzyme from glucose in a physiological environment, reducing systemic toxicity. The fabricated nanoreactor with high enzyme loading capacity and good biocompatibility could deliver GOx and TPZ to the tumors, thereby exhausting glucose, generating H2O2, and aggravating hypoxic microenvironment for starvation therapy, DNA damage, and deoxygenation-activated chemotherapy. Significantly, the synergistic therapy effectively suppressed the breast cancer metastasis in mice and prolonged life without systemic toxicity. The in vitro and in vivo results provided evidence that our biomimetic nanoreactor had a powerful synergistic cascade effect in treating breast cancer.Conclusion: GTZ@Z-RBM NPs can be used as an 'ON/OFF' intelligent nanoreactor to deliver GOx and TPZ for multimodal synergistic therapy and tumor metastasis suppression.