RESUMO
From a mouse triple-negative breast cancer cell line, 4T1, we previously established 4T1.3 clone with a high capacity to metastasize to bone after its orthotopic injection into mammary fat pad of immunocompetent mice. Subsequent analysis demonstrated that the interaction between cancer cells and fibroblasts in a bone cavity was crucial for bone metastasis focus formation arising from orthotopic injection of 4T1.3 cells. Here, we demonstrated that a member of the adhesion G-protein-coupled receptor (ADGR) family, G-protein-coupled receptor 56 (GPR56)/adhesion G-protein-coupled receptor G1 (ADGRG1), was expressed selectively in 4T1.3 grown in a bone cavity but not under in vitro conditions. Moreover, fibroblasts present in bone metastasis sites expressed type III collagen, a ligand for GPR56/ADGRG1. Consistently, GPR56/ADGRG1 proteins were detected in tumor cells in bone metastasis foci of human breast cancer patients. Deletion of GPR56/ADGRG1 from 4T1.3 cells reduced markedly intraosseous tumor formation upon their intraosseous injection. Conversely, intraosseous injection of GPR56/ADGRG1-transduced 4T1, TS/A (mouse breast cancer cell line), or MDA-MB-231 (human breast cancer cell line) exhibited enhanced intraosseous tumor formation. Furthermore, we proved that the cleavage at the extracellular region was indispensable for GPR56/ADGRG1-induced increase in breast cancer cell growth upon its intraosseous injection. Finally, inducible suppression of Gpr56/Adgrg1 gene expression in 4T1.3 cells attenuated bone metastasis formation with few effects on primary tumor formation in the spontaneous breast cancer bone metastasis model. Altogether, GPR56/ADGRG1 can be a novel target molecule to develop a strategy to prevent and/or treat breast cancer metastasis to bone.
Assuntos
Neoplasias Ósseas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Mamárias Experimentais/genética , Receptores Acoplados a Proteínas G/genética , Animais , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Linhagem Celular Tumoral , Proliferação de Células/genética , Colágeno Tipo III/metabolismo , Feminino , Deleção de Genes , Humanos , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos Endogâmicos BALB C , Camundongos SCID , Ligação Proteica , Receptores Acoplados a Proteínas G/metabolismo , Carga Tumoral/genéticaRESUMO
Macrophages in lungs can be classified into two subpopulations, alveolar macrophages (AMs) and interstitial macrophages (IMs), which reside in the alveolar and interstitial spaces, respectively. Accumulating evidence indicates the involvement of IMs in lung metastasis, but the roles of AMs in lung metastasis still remain elusive. An i.v. injection of a mouse hepatocellular carcinoma (HCC) cell line, BNL, caused lung metastasis foci with infiltration of AMs and IMs. Comprehensive determination of arachidonic acid metabolite levels revealed increases in leukotrienes and PGs in lungs in this metastasis model. A 5-lipoxygenase (LOX) inhibitor but not a cyclooxygenase inhibitor reduced the numbers of metastatic foci, particularly those of a larger size. A major 5-LOX metabolite, LTB4, augmented in vitro cell proliferation of human HCC cell lines as well as BNL cells. Moreover, in this lung metastasis course, AMs exhibited higher expression levels of the 5-LOX and LTB4 than IMs. Consistently, 5-LOX-expressing AMs increased in the lungs of human HCC patients with lung metastasis, compared with those without lung metastasis. Furthermore, intratracheal clodronate liposome injection selectively depleted AMs but not IMs, together with reduced LTB4 content and metastatic foci numbers in this lung metastasis process. Finally, IMs in mouse metastatic foci produced CCL2, thereby recruiting blood-borne, CCR2-expressing AMs into lungs. Thus, AMs can be recruited under the guidance of IM-derived CCL2 into metastatic lungs and can eventually contribute to the progression of lung metastasis by providing a potent arachidonic acid-derived tumor growth promoting mediator, LTB4.
Assuntos
Carcinoma Hepatocelular/metabolismo , Leucotrieno B4/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Pulmonares/metabolismo , Pulmão/metabolismo , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patologia , Animais , Araquidonato 5-Lipoxigenase/metabolismo , Ácido Araquidônico/farmacologia , Líquido da Lavagem Broncoalveolar , Carcinoma Hepatocelular/patologia , Linhagem Celular , Linhagem Celular Tumoral , Inibidores de Ciclo-Oxigenase/farmacologia , Humanos , Leucotrienos/metabolismo , Neoplasias Hepáticas/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Neoplasias Pulmonares/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos Alveolares/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
CCL4, a CC chemokine, previously known as macrophage inflammatory protein (MIP)-1ß, has diverse effects on various types of immune and nonimmune cells by the virtue of its interaction with its specific receptor, CCR5, in collaboration with related but distinct CC chemokines such as CCL3 and CCL5, which can also bind CCR5. Several lines of evidence indicate that CCL4 can promote tumor development and progression by recruiting regulatory T cells and pro-tumorigenic macrophages, and acting on other resident cells present in the tumor microenvironment, such as fibroblasts and endothelial cells, to facilitate their pro-tumorigenic capacities. These observations suggest the potential efficacy of CCR5 antagonists for cancer treatment. On the contrary, under some situations, CCL4 can enhance tumor immunity by recruiting cytolytic lymphocytes and macrophages with phagocytic ability. Thus, presently, the clinical application of CCR5 antagonists warrants more detailed analysis of the role of CCL4 and other CCR5-binding chemokines in the tumor microenvironment.
Assuntos
Quimiocina CCL4/metabolismo , Transdução de Sinais , Microambiente Tumoral , Animais , Quimiocina CCL4/imunologia , Humanos , Macrófagos/imunologia , Receptores CCR5/metabolismo , Linfócitos T Reguladores/imunologiaRESUMO
Neutrophils are the most abundant circulating leukocytes in humans. Neutrophil infiltration into tumor tissues has long been observed but its roles have been ignored due to the presumed short life cycle and metabolic incompetence of neutrophils. Recent advances in neutrophil biology research have revealed that neutrophils have a longer life cycle with a potential to express various bioactive molecules. Clinical studies have simultaneously unraveled an increase in the neutrophil-lymphocyte ratio (NLR), a ratio of absolute neutrophil to absolute lymphocyte numbers in cancer patient peripheral blood and an association of higher NLR with more advanced or aggressive disease. As a consequence, tumor-associated neutrophils (TANs) have emerged as important players in tumor microenvironment. The elucidation of the roles of TANs, however, has been hampered by their multitude of plasticity in terms of phenotypes and functionality. Difficulties are further enhanced by the presence of a related cell population-polymorphonuclear leukocyte (PMN)-myeloid-derived suppressor cells (MDSCs)-and various dissimilar aspects of neutrophil biology between humans and mice. Here, we discuss TAN biology in various tumorigenesis processes, and particularly focus on the context-dependent functional heterogeneity of TANs.
Assuntos
Carcinogênese/genética , Neoplasias/sangue , Infiltração de Neutrófilos/genética , Neutrófilos/patologia , Linhagem da Célula/genética , Humanos , Contagem de Leucócitos , Contagem de Linfócitos , Células Supressoras Mieloides/patologia , Neoplasias/genética , Neoplasias/patologia , Células Neoplásicas Circulantes/patologia , Microambiente Tumoral/genéticaRESUMO
An intravenous administration of a high-dose antigen (Ag) can induce immune tolerance and suppress the immune response, but the mechanism remains unclear. We recently proved that a combined i.v. administration of OVA and IL-2-anti-IL-2 Ab immune complexes (IL-2 ICs) efficiently expands OVA-specific Treg cells in the thymus and induces their migration into peripheral blood, by using OVA-specific TCR Tg-expressing DO11.10 mice. Here, we demonstrate that the expanded OVA-specific Treg cells rapidly move into the air pouch after OVA injection in DO11.10 mice. The migration was inhibited by blocking the axis of a chemokine receptor, CCR2. Moreover, prior treatment with OVA and IL-2 ICs enhanced OVA-specific Treg-cell migration and inhibited OVA-induced delayed-type hypersensitivity (DTH) reactions in the skin of BM chimeric mice with 15% of T cells expressing OVA-specific TCR. Blocking the CCR2 axis reversed this suppression of DTH in these mice. Furthermore, prior treatment with OVA and IL-2 ICs effectively reduced DTH reactions even in WT mice possessing only a very small population of OVA-specific T cells. Thus, the treatment with Ag and IL-2 ICs can efficiently expand Ag-specific Treg cells with the capacity to migrate and reduce localized immune responses.
Assuntos
Complexo Antígeno-Anticorpo/imunologia , Quimiocinas/imunologia , Interleucina-2/imunologia , Ovalbumina/imunologia , Linfócitos T Reguladores/imunologia , Administração Intravenosa , Animais , Complexo Antígeno-Anticorpo/administração & dosagem , Movimento Celular/efeitos dos fármacos , Movimento Celular/imunologia , Proliferação de Células/efeitos dos fármacos , Quimiocinas/metabolismo , Feminino , Citometria de Fluxo , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/prevenção & controle , Inflamação/genética , Inflamação/imunologia , Interleucina-2/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Transgênicos , Ovalbumina/administração & dosagem , Receptores CCR2/deficiência , Receptores CCR2/genética , Receptores CCR2/imunologia , Linfócitos T Reguladores/metabolismo , Timo/imunologia , Timo/metabolismo , Timo/patologiaRESUMO
Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization.
Assuntos
Desoxicitidina/análogos & derivados , Interleucina-8/metabolismo , Neovascularização Patológica/induzido quimicamente , Neovascularização Patológica/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/efeitos adversos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Relação Dose-Resposta a Droga , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , NF-kappa B/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Espécies Reativas de Oxigênio/metabolismo , Resultado do Tratamento , Regulação para Cima/efeitos dos fármacos , GencitabinaRESUMO
Patients with inflammatory bowel diseases often develop colon carcinoma. Combined treatment of azoxymethane (AOM) and dextran sulfate sodium (DSS) recapitulates colitis-associated cancer in mice. AOM/DSS-induced tumor formation was reduced in CCL3- or its specific receptor, CCR5-deficient mice despite the presence of a massive infiltration of inflammatory cells. However, AOM/DSS-induced type I collagen-positive fibroblast accumulation in the colon was reduced in CCL3- or CCR5-deficient mice. This was associated with depressed expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF), which is expressed mainly by fibroblasts. Moreover in vitro, CCL3 induced fibroblasts to proliferate and to enhance HB-EGF expression. Furthermore, CCR5 blockade reduced tumor formation together with reduced fibroblast accumulation and HB-EGF expression, even when administered after the development of multiple colon tumors. Thus, CCL3-CCR5-mediated fibroblast accumulation may be required, in addition to leukocyte infiltration, to induce full-blown colitis-associated carcinogenesis. Our studies shed light on a therapeutic potential of CCR5 antagonist for patients with colitis-associated cancer.
Assuntos
Carcinogênese/metabolismo , Quimiocina CCL3/metabolismo , Colite/metabolismo , Neoplasias do Colo/metabolismo , Fibroblastos/metabolismo , Receptores CCR5/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Carcinogênese/patologia , Colite/patologia , Neoplasias do Colo/patologia , Feminino , Fibroblastos/patologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Chemokines were initially identified as bioactive substances, which control the trafficking of inflammatory cells including granulocytes and monocytes/macrophages. Moreover, chemokines have profound impacts on other types of cells associated with inflammatory responses, such as endothelial cells and fibroblasts. These observations would implicate chemokines as master regulators in various inflammatory responses. Subsequent studies have further revealed that chemokines can regulate the movement of a wide variety of immune cells including lymphocytes, natural killer cells, and dendritic cells in both physiological and pathological conditions. These features endow chemokines with crucial roles in immune responses. Furthermore, increasing evidence points to the vital effects of several chemokines on the proliferative and invasive properties of cancer cells. It is widely acknowledged that cancer develops and progresses to invade and metastasize in continuous interaction with noncancerous cells present in cancer tissues, such as macrophages, lymphocytes, fibroblasts, and endothelial cells. The capacity of chemokines to regulate both cancerous and noncancerous cells highlights their crucial roles in cancer development and progression. Here, we will discuss the roles of chemokines in carcinogenesis and the possibility of chemokine targeting therapy for the treatment of cancer.
Assuntos
Quimiocinas/imunologia , Regulação Neoplásica da Expressão Gênica , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Animais , Antineoplásicos/química , Movimento Celular , Células Dendríticas/imunologia , Progressão da Doença , Células Endoteliais/citologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Fatores Imunológicos/química , Inflamação , Leucócitos/citologia , Macrófagos/imunologia , Camundongos , Metástase Neoplásica , Neoplasias/patologia , Transdução de SinaisRESUMO
Regular exercise has recognized health benefits, partly because it reportedly lowers the levels of the oxidation products of proteins and DNA at rest, in contrast with the effect of acute exercise. However, when we compared oxidative response markers in active middle-aged subjects with those in sedentary ones, the level of urinary 8-OHdG was higher in active subjects. Because neutrophils are the first line of defense against a variety of infectious diseases, we then compared the cell density, functions and apoptosis of neutrophils in active subjects with those in sedentary ones. The cell density of neutrophils and phagocytosis of opsonized zymosan by neutrophils were higher in active subjects, being similar with the reported effects of acute exercise. To determine any beneficial effects of oxidative stress in active subjects, we then compared the levels of antibodies against 4-hydroxy-2-nonenal adducts in active subjects with those in sedentary ones, because 4-hydroxy-2-nonenal is one of the most common bioactive aldehyde products of oxidative stress, and because the IgM class of antibodies against oxidized low-density lipoprotein is associated with atheroprotective properties. The level of the IgM but not the IgG class of antibodies against 4-hydroxy-2-nonenal adducts was higher in active subjects. Overall, this study revealed that our active middle-aged subjects showed both oxidative responses and a higher IgM response to reactive carbonyl derivatives, possibly providing a basis for a health benefit by exercise in our active subjects.
Assuntos
Exercício Físico/fisiologia , Neutrófilos/imunologia , Estresse Oxidativo/imunologia , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Idoso , Aldeídos/imunologia , Anticorpos/sangue , Anticorpos/imunologia , Formação de Anticorpos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/urina , Humanos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/imunologiaRESUMO
We found previously that neutrophil-depleted mice exhibited significant blockading of both the regular estrous cycle and cyclic changes of steroid hormone levels. In this study, we aimed at elucidation of the underlying mechanism. To examine the possibility that an increase in bacteria in the vaginal vault of neutrophil-depleted mice causes blockading of the estrous cycle, we treated neutrophil-depleted mice with antibiotics but failed to restore the estrous cycle. We then examined another possibility that neutrophils regulate the estrous cycle via opioid peptides, because opioid peptides regulate steroidogenesis in theca and granulosa cells in the ovaries, and because neutrophils contain opioid peptides. In support of this possibility, naloxone, an opioid antagonist, blocked the estrous cycle and a µ opioid receptor agonist restored the estrous cycle in neutrophil-depleted mice. Pro-opiomelanocortin was immunohistochemically detected in peripheral blood neutrophils but not in ones that had infiltrated into the ovaries. i.v. injection of anti-MIP-2 polyclonal Ab caused blockading of the estrous cycle, whereas MIP-2 was detected in the ovaries, suggesting a role of MIP-2 in the regulation of the estrous cycle. Moreover, i.v. injection of MIP-2 decreased the pro-opiomelanocortin signal in peripheral blood neutrophils and caused blockading of the estrous cycle. Together, these results suggest that neutrophils maintain the estrous cycle via opioid peptides.
Assuntos
Ciclo Estral/imunologia , Neutrófilos/imunologia , Peptídeos Opioides/fisiologia , Animais , Quimiocina CXCL2/fisiologia , Ciclo Estral/efeitos dos fármacos , Feminino , Camundongos , Camundongos Endogâmicos ICR , Naloxona/farmacologia , Neutropenia/imunologia , Neutropenia/metabolismo , Neutropenia/patologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Peptídeos Opioides/metabolismo , Ovário/imunologia , Ovário/metabolismo , Receptores Opioides mu/agonistas , Receptores Opioides mu/antagonistas & inibidores , beta-Endorfina/metabolismoRESUMO
(1) Background: Although the important role of dietary energy intake in regulating both cancer progression and host immunity has been widely recognized, it remains unclear whether dietary calorie restriction (CR) has any impact on anti-tumor immune responses. (2) Methods: Using an immunogenic B16 melanoma cell expressing ovalbumin (B16-OVA), we examined the effect of the CR diet on B16-OVA tumor growth and host immune responses. To further test whether the CR diet affects the efficacy of cancer immunotherapy, we examined the effect of CR against anti-PD-1 monoclonal antibody (anti-PD-1 Ab) treatment. (3) Results: The CR diet significantly slowed down the tumor growth of B16-OVA without affecting both CD4+ and CD8+ T cell infiltration into the tumor. Although in vivo depletion of CD8+ T cells facilitated B16-OVA tumor growth in the control diet group, there was no significant change in the tumor growth in the CR diet group with or without CD8+ T cell-depletion. Anti-PD-1 Ab treatment lost its efficacy to suppress tumor growth along with the activation and metabolic shift of CD8+ T cells under CR condition. (4) Conclusions: Our present results suggest that a physical condition restricted in energy intake in cancer patients may impair CD8+ T cell immune surveillance and the efficacy of immunotherapy.
Assuntos
Restrição Calórica , Melanoma Experimental , Humanos , Animais , Linfócitos T CD8-Positivos , Ingestão de Energia , Melanoma Experimental/terapia , ImunidadeRESUMO
Anti-human immunodeficiency virus (HIV) drug abacavir (ABC) binds to the specific allele of human leukocyte antigen (HLA-B*57:01) and activates CD8+ T cells by presenting altered abnormal peptides. Here, we examined the effect of ABC-induced altered self-presentation by HLA-B*57:01 on immunogenicity of cancer cells and CD8+ T-cell-dependent anti-tumor immunity. We established human-mouse chimeric HLA-B*57:01-expressing tumor cell lines (B16F10 and 3LL) and tested the anti-tumor effect of ABC in vivo. ABC treatment inhibited the growth of HLA-B*57:01-expressing tumors by a CD8+ T-cell-dependent mechanism. ABC treatment induced CXCR3-dependent infiltration of CD8+ T cells into HLA-B*57:01-expressing tumors, and activated those tumor-infiltrating CD8+ T cells to proliferate and secrete IFN-γ. The activation of CD8+ T cells using drug-induced altered self-presentation may be a new strategy to increase tumor immunogenicity and improve the efficacy of immunotherapy.
Assuntos
Antígenos de Neoplasias , Linfócitos T CD8-Positivos , Camundongos , Animais , Linhagem Celular Tumoral , ImunoterapiaRESUMO
AIMS: Cancer metastasis is a major cause of lung cancer-related mortality, so identification of related molecular mechanisms is of interest. Calmodulin-regulated spectrin-associated protein 3 (CAMSAP3) has been implicated in lung cancer malignancies; however, its role in metastatic processes, including invasion and angiogenesis, is largely unknown. MAIN METHOD: The clinical relevance of CAMSAP3 expression in lung cancer was evaluated. The relevance of CAMSAP3 expression to in vitro cell invasion and angiogenesis was assessed in human lung cancer cells and endothelial cells, respectively. The molecular mechanism was identified by qRT-PCR, immunoprecipitation, mass spectrometry, and RNA immunoprecipitation. The in vivo metastatic and angiogenic activities of lung cancer cells were assessed. KEY FINDINGS: Low CAMSAP3 expression was found in malignant lung tissues and strongly correlated with a poor prognosis in lung adenocarcinoma (LUAD). CAMSAP3-knockout NSCLC exhibited high invasive ability, and CAMSAP3 knockout induced HUVEC proliferation and tube formation; these effects were significantly attenuated by reintroduction of exogenous wild-type CAMSAP3. Mechanistically, in the absence of CAMSAP3, the expression of hypoxia-inducible factor-1α (HIF-1α) was upregulated, which increased the levels of downstream HIF-1α targets such as vascular endothelial growth factor A (VEGFA) and matrix metalloproteinases (MMPs) 2 and 9. Proteomic analysis revealed that nucleolin (NCL) bound to CAMSAP3 to regulate HIF-1α mRNA stabilization. In addition, CAMSAP3-knockout lung cancer cells displayed highly aggressive behavior in metastasis and angiogenesis in vivo. SIGNIFICANCE: This study reveals that CAMSAP3 plays a negative regulatory role in lung cancer cell metastatic behavior both in vitro and in vivo through NCL/HIF-1α mRNA complex stabilization.
Assuntos
Neoplasias Pulmonares , Espectrina , Humanos , Espectrina/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Células Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteômica , Linhagem Celular Tumoral , Neoplasias Pulmonares/patologia , Regulação Neoplásica da Expressão Gênica , Pulmão/metabolismo , Invasividade Neoplásica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , NucleolinaRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a biosafety level (BSL)-3 pathogen; therefore, its research environment is limited. Pseudotyped viruses that mimic the infection of SARS-CoV-2 have been widely used for in vitro evaluation because they are available in BSL-2 containment laboratories. However, in vivo application is inadequate. Therefore, animal models instigated with animal BSL-2 will provide opportunities for in vivo evaluation. Hamsters (6-10-week-old males) were intratracheally inoculated with luciferase-expressing vesicular stomatitis virus (VSV)-based SARS-CoV-2 pseudotyped virus. The lungs were harvested 24-72 h after inoculation and luminescence was measured using an in vivo imaging system. Lung luminescence after inoculation with the SARS-CoV-2 pseudotyped virus increased in a dose-dependent manner and peaked at 48 h. The VSV-G (envelope G) pseudotyped virus also induced luminescence; however, a 100-fold concentration was required to reach a level similar to that of the SARS-CoV-2 pseudotyped virus. The SARS-CoV-2 pseudotyped virus is applicable to SARS-CoV-2 respiratory infections in a hamster model. Because of the single-round infectious virus, the model can be used to study the steps from viral binding to entry, which will be useful for future research on SARS-CoV-2 entry without using live SARS-CoV-2 or transgenic animals.
Assuntos
COVID-19 , SARS-CoV-2 , Animais , Cricetinae , Masculino , Taxa Respiratória , Sistema Respiratório , Pseudotipagem ViralRESUMO
Many potent neutralizing SARS-CoV-2 antibodies have been developed and used for therapies. However, the effectiveness of many antibodies has been reduced against recently emerging SARS-CoV-2 variants, especially the Omicron variant. We identified a highly potent SARS-CoV-2 neutralizing antibody, UT28K, in COVID-19 convalescent individuals who recovered from a severe condition. UT28K showed efficacy in neutralizing SARS-CoV-2 in an in vitro assay and in vivo prophylactic treatment, and the reactivity to the Omicron strain was reduced. The structural analyses revealed that antibody UT28K Fab and SARS-CoV-2 RBD protein interactions were mainly chain-dominated antigen-antibody interactions. In addition, a mutation analysis suggested that the emergence of a UT28K neutralization-resistant SARS-CoV-2 variant was unlikely, as this variant would likely lose its competitive advantage over circulating SARS-CoV-2. Our data suggest that UT28K offers potent protection against SARS-CoV-2, including newly emerging variants.
Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , HumanosRESUMO
Bone metastasis is frequently complicated in patients with advanced solid cancers such as breast, prostate and lung cancers, and impairs patients' quality of life and prognosis. At the first step of bone metastasis, cancer cells adhere to the endothelium in bone marrow and survive in a dormant state by utilizing hematopoietic niches present therein. Once a dormant stage is disturbed, cancer cells grow through the interaction with various bone marrow resident cells, particularly osteoclasts and osteoblasts. Consequently, osteoclast activation is a hallmark of bone metastasis. As a consequence, the drugs targeting osteoclast activation are frequently used to treat bone metastasis but are not effective to inhibit cancer cell growth in bone marrow. Thus, additional types of resident cells are presumed to contribute to cancer cell growth in bone metastasis sites. Cancer-associated fibroblasts (CAFs) are fibroblasts that accumulate in cancer tissues and can have diverse roles in cancer progression and metastasis. Given the presence of CAFs in bone metastasis sites, CAFs are emerging as an important cellular player in bone metastasis. Hence, in this review, we will discuss the potential roles of CAFs in tumor progression, particularly bone metastasis.
RESUMO
Patients with triple negative breast cancer (TNBC) is frequently complicated by bone metastasis, which deteriorates the life expectancy of this patient cohort. In order to develop a novel type of therapy for bone metastasis, we established 4T1.3 clone with a high capacity to metastasize to bone after orthotopic injection, from a murine TNBC cell line, 4T1.0. To elucidate the molecular mechanism underlying a high growth ability of 4T1.3 in a bone cavity, we searched for a novel candidate molecule with a focus on a transcription factor whose expression was selectively enhanced in a bone cavity. Comprehensive gene expression analysis detected enhanced Nfe2 mRNA expression in 4T1.3 grown in a bone cavity, compared with in vitro culture conditions. Moreover, Nfe2 gene transduction into 4T1.0 cells enhanced their capability to form intraosseous tumors. Moreover, Nfe2 shRNA treatment reduced tumor formation arising from intraosseous injection of 4T1.3 clone as well as another mouse TNBC-derived TS/A.3 clone with an augmented intraosseous tumor formation ability. Furthermore, NFE2 expression was associated with in vitro growth advantages of these TNBC cell lines under hypoxic condition, which mimics the bone microenvironment, as well as Wnt pathway activation. These observations suggest that NFE2 can potentially contribute to breast cancer cell survival in the bone microenvironment.
RESUMO
During metestrus of the estrous cycle, a number of neutrophils infiltrate into the vaginal vault, presumably due to a neutrophil-specific chemokine, MIP-2, in mice. The physiological role of the infiltrating neutrophils, however, remains largely obscure. In this study we examined the effects of neutrophil depletion on the estrous cycle and steroid hormone levels. When mice were treated with an anti-Gr-1 mAb, they became neutropenic, as assessed as to the number of neutrophils in the peripheral blood. The estrous cycle of such mice was specifically blocked at diestrus irrespective of the phase at which the anti-Gr-1 mAb was administered. The blockade was reversible, because restoration of neutrophils to a normal level caused a restart of the cycle. Immunohistochemical analyses revealed that neutrophils were present mainly on the luminal surface and in the lumen at metestrus and to a lesser extent at diestrus but scarcely in the uterine cervix at any phase, and that the anti-Gr-1 mAb depleted neutrophils but not eosinophils in the vagina. The treatment with the anti-Gr-1 mAb significantly affected the serum 17beta-estradiol and progesterone levels at diestrus after the estrous cycle was blocked. Together, these results suggest that neutrophil infiltration into the vagina is critical in maintaining the estrous cycle through control of steroid hormone levels.
Assuntos
Ciclo Estral/imunologia , Infiltração de Neutrófilos , Neutrófilos/imunologia , Vagina/imunologia , Animais , Anticorpos Monoclonais/imunologia , Estradiol/sangue , Feminino , Procedimentos de Redução de Leucócitos , Camundongos , Camundongos Endogâmicos ICR , Progesterona/sangue , Receptores de Quimiocinas/imunologiaRESUMO
Tumor recurrence is attributable to cancer stem-like cells (CSCs), the metabolic mechanisms of which currently remain obscure. Here, we uncovered the critical role of folate-mediated one-carbon (1C) metabolism involving mitochondrial methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) and its downstream purine synthesis pathway. MTHFD2 knockdown greatly reduced tumorigenesis and stem-like properties, which were associated with purine nucleotide deficiency, and caused marked accumulation of 5-aminoimidazole carboxamide ribonucleotide (AICAR)-the final intermediate of the purine synthesis pathway. Lung cancer cells with acquired resistance to the targeted drug gefitinib, caused by elevated expression of components of the ß-catenin pathway, exhibited increased stem-like properties and enhanced expression of MTHFD2. MTHFD2 knockdown or treatment with AICAR reduced the stem-like properties and restored gefitinib sensitivity in these gefitinib-resistant cancer cells. Moreover, overexpression of MTHFD2 in gefitinib-sensitive lung cancer cells conferred resistance to gefitinib. Thus, MTHFD2-mediated mitochondrial 1C metabolism appears critical for cancer stem-like properties and resistance to drugs including gefitinib through consumption of AICAR, leading to depletion of the intracellular pool of AICAR. Because CSCs are dependent on MTHFD2, therapies targeting MTHFD2 may eradicate tumors and prevent recurrence.
Assuntos
Aminoidrolases/metabolismo , Resistencia a Medicamentos Antineoplásicos/fisiologia , Gefitinibe/farmacologia , Redes e Vias Metabólicas/fisiologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo , Mitocôndrias/metabolismo , Enzimas Multifuncionais/metabolismo , Células-Tronco Neoplásicas/metabolismo , Purinas/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/metabolismo , Carcinogênese/metabolismo , Carcinogênese/patologia , Linhagem Celular , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ácido Fólico/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Mitocôndrias/patologia , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Ribonucleotídeos/metabolismo , beta Catenina/metabolismoRESUMO
Cancer cell-intrinsic properties caused by oncogenic mutations have been well characterized; however, how specific oncogenes and tumor suppressors impact the tumor microenvironment (TME) is not well understood. Here, we present a novel non-cell-autonomous function of the retinoblastoma (RB) tumor suppressor in controlling the TME. RB inactivation stimulated tumor growth and neoangiogenesis in a syngeneic and orthotropic murine soft-tissue sarcoma model, which was associated with recruitment of tumor-associated macrophages (TAM) and immunosuppressive cells such as Gr1+CD11b+ myeloid-derived suppressor cells (MDSC) or Foxp3+ regulatory T cells (Treg). Gene expression profiling and analysis of genetically engineered mouse models revealed that RB inactivation increased secretion of the chemoattractant CCL2. Furthermore, activation of the CCL2-CCR2 axis in the TME promoted tumor angiogenesis and recruitment of TAMs and MDSCs into the TME in several tumor types including sarcoma and breast cancer. Loss of RB increased fatty acid oxidation (FAO) by activating AMP-activated protein kinase that led to inactivation of acetyl-CoA carboxylase, which suppresses FAO. This promoted mitochondrial superoxide production and JNK activation, which enhanced CCL2 expression. These findings indicate that the CCL2-CCR2 axis could be an effective therapeutic target in RB-deficient tumors. SIGNIFICANCE: These findings demonstrate the cell-nonautonomous role of the tumor suppressor retinoblastoma in the tumor microenvironment, linking retinoblastoma loss to immunosuppression.