RESUMO
BRCA1 functions at two distinct steps during homologous recombination (HR). Initially, it promotes DNA end resection, and subsequently it recruits the PALB2 and BRCA2 mediator complex, which stabilizes RAD51-DNA nucleoprotein filaments. Loss of 53BP1 rescues the HR defect in BRCA1-deficient cells by increasing resection, suggesting that BRCA1's downstream role in RAD51 loading is dispensable when 53BP1 is absent. Here we show that the E3 ubiquitin ligase RNF168, in addition to its canonical role in inhibiting end resection, acts in a redundant manner with BRCA1 to load PALB2 onto damaged DNA. Loss of RNF168 negates the synthetic rescue of BRCA1 deficiency by 53BP1 deletion, and it predisposes BRCA1 heterozygous mice to cancer. BRCA1+/-RNF168-/- cells lack RAD51 foci and are hypersensitive to PARP inhibitor, whereas forced targeting of PALB2 to DNA breaks in mutant cells circumvents BRCA1 haploinsufficiency. Inhibiting the chromatin ubiquitin pathway may, therefore, be a synthetic lethality strategy for BRCA1-deficient cancers.
Assuntos
Proteína BRCA1/genética , Cromatina/enzimologia , Fibroblastos/enzimologia , Haploinsuficiência , Neoplasias/enzimologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Animais , Proteína BRCA2/genética , Linhagem Celular Tumoral , Cromatina/genética , Dano ao DNA , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Reparo de DNA por Recombinação , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genéticaRESUMO
BACKGROUND: Olfactory neuroblastoma is a rare malignancy of the anterior skull base typically treated with surgery and adjuvant radiation. Although outcomes are fair for low-grade disease, patients with high-grade, recurrent, or metastatic disease oftentimes respond poorly to standard treatment methods. We hypothesized that an in-depth evaluation of the olfactory neuroblastoma tumor immune microenvironment would identify mechanisms of immune evasion in high-grade olfactory neuroblastoma as well as rational targetable mechanisms for future translational immunotherapeutic approaches. METHODS: Multispectral immunofluorescence and RNAScope evaluation of the tumor immune microenvironment was performed on forty-seven clinically annotated olfactory neuroblastoma samples. A retrospective chart review was performed and clinical correlations assessed. RESULTS: A significant T cell infiltration was noted in olfactory neuroblastoma samples with a stromal predilection, presence of myeloid-derived suppressor cells, and sparse natural killer cells. A striking decrease was observed in MHC-I expression in high-grade olfactory neuroblastoma compared to low-grade disease, representing a mechanism of immune evasion in high-grade disease. Mechanistically, the immune effector stromal predilection appears driven by low tumor cell MHC class II (HLA-DR), CXCL9, and CXCL10 expression as those tumors with increased tumor cell expression of each of these mediators correlated with significant increases in T cell infiltration. CONCLUSION: These data suggest that immunotherapeutic strategies that augment tumor cell expression of MHC class II, CXCL9, and CXCL10 may improve parenchymal trafficking of immune effector cells in olfactory neuroblastoma and augment immunotherapeutic responses.
Assuntos
Quimiocina CXCL10 , Quimiocina CXCL9 , Estesioneuroblastoma Olfatório , Antígenos HLA-DR , Imunoterapia , Microambiente Tumoral , Humanos , Estesioneuroblastoma Olfatório/terapia , Estesioneuroblastoma Olfatório/patologia , Estesioneuroblastoma Olfatório/imunologia , Quimiocina CXCL10/metabolismo , Imunoterapia/métodos , Feminino , Masculino , Pessoa de Meia-Idade , Quimiocina CXCL9/metabolismo , Microambiente Tumoral/imunologia , Antígenos HLA-DR/metabolismo , Idoso , Neoplasias Nasais/terapia , Neoplasias Nasais/patologia , Neoplasias Nasais/imunologia , Adulto , Regulação Neoplásica da Expressão GênicaRESUMO
We have shown previously that phosphorylation of Mdm2 by ATM and c-Abl regulates Mdm2-p53 signaling and alters the effects of DNA damage in mice, including bone marrow failure and tumorigenesis induced by ionizing radiation. Here, we examine the physiological effects of Mdm2 phosphorylation by Akt, another DNA damage effector kinase. Surprisingly, Akt phosphorylation of Mdm2 does not alter the p53-mediated effects of ionizing radiation in cells or mice but regulates the p53 response to oxidative stress. Akt phosphorylation of Mdm2 serine residue 183 increases nuclear Mdm2 stability, decreases p53 levels, and prevents senescence in primary cells exposed to reactive oxidative species (ROS). Using multiple mouse models of ROS-induced cancer, we show that Mdm2 phosphorylation by Akt reduces senescence to promote KrasG12D-driven lung cancers and carcinogen-induced papilloma and hepatocellular carcinomas. Collectively, we document a unique physiologic role for Akt-Mdm2-p53 signaling in regulating cell growth and tumorigenesis in response to oxidative stress.
Assuntos
Neoplasias Induzidas por Radiação/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Carcinogênese/efeitos da radiação , Carcinógenos/toxicidade , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/virologia , Proliferação de Células/genética , Senescência Celular/efeitos dos fármacos , Senescência Celular/efeitos da radiação , Dano ao DNA/genética , Dano ao DNA/efeitos da radiação , Modelos Animais de Doenças , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Neoplasias Induzidas por Radiação/patologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Papillomaviridae/patogenicidade , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Radiação Ionizante , Espécies Reativas de Oxigênio/metabolismoRESUMO
Recombinant immunotoxins (RITs) are chimeric proteins composed of an Fv and a protein toxin being developed for cancer treatment. The Fv brings the toxin to the cancer cell, but most of the RITs do not reach the tumor and are removed by other organs. To identify cells responsible for RIT removal, and the pathway by which RITs reach these cells, we studied SS1P, a 63-kDa RIT that targets mesothelin-expressing tumors and has a short serum half-life. The major organs that remove RIT were identified by live mouse imaging of RIT labeled with FNIR-Z-759. Cells responsible for SS1P removal were identified by immunohistochemistry and intravital two-photon microscopy of kidneys of rats. The primary organ of SS1P removal is kidney followed by liver. In the kidney, SS1P passes through the glomerulus, is taken up by proximal tubular cells, and transferred to lysosomes. In the liver, macrophages are involved in removal. The short half-life of SS1P is due to its very rapid filtration by the kidney followed by degradation in proximal tubular cells of the kidney. In mice treated with SS1P, proximal tubular cells are damaged and albumin in the urine is increased. SS1P uptake by kidney is reduced by coadministration of l-lysine. Our data suggests that l-lysine administration to humans might prevent SS1P-mediated kidney damage, reduce albumin loss in urine, and alleviate capillary leak syndrome.
Assuntos
Albuminúria/patologia , Anticorpos Monoclonais/farmacocinética , Síndrome de Vazamento Capilar/patologia , Imunotoxinas/farmacocinética , Túbulos Renais Proximais/efeitos dos fármacos , Albuminúria/induzido quimicamente , Albuminúria/prevenção & controle , Albuminúria/urina , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/química , Anticorpos Monoclonais/toxicidade , Síndrome de Vazamento Capilar/induzido quimicamente , Síndrome de Vazamento Capilar/prevenção & controle , Síndrome de Vazamento Capilar/urina , Modelos Animais de Doenças , Feminino , Corantes Fluorescentes/química , Meia-Vida , Humanos , Imunotoxinas/administração & dosagem , Imunotoxinas/química , Imunotoxinas/toxicidade , Microscopia Intravital , Glomérulos Renais/metabolismo , Túbulos Renais Proximais/diagnóstico por imagem , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Lisina/administração & dosagem , Mesotelina , Camundongos , Microscopia de Fluorescência , Neoplasias/tratamento farmacológico , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/toxicidade , Eliminação Renal/efeitos dos fármacos , Albumina Sérica/análise , Albumina Sérica/metabolismo , Coloração e RotulagemRESUMO
Elevated expression of CD47 in some cancers is associated with poor survival related to its function as an innate immune checkpoint when expressed on tumor cells. In contrast, elevated CD47 expression in cutaneous melanomas is associated with improved survival. Previous studies implicated protective functions of CD47 expressed by immune cells in the melanoma tumor microenvironment. RNA sequencing analysis of responses induced by CD3 and CD28 engagement on wild type and CD47-deficient Jurkat T lymphoblast cells identified additional regulators of T cell function that were also CD47-dependent in mouse CD8 T cells. MYCN mRNA expression was upregulated in CD47-deficient cells but downregulated in CD47-deficient cells following activation. CD47 also regulated alternative splicing that produces two N-MYC isoforms. The CD47 ligand thrombospondin-1 inhibited expression of these MYCN mRNA isoforms, as well as induction of the oncogenic decoy MYCN opposite strand (MYCNOS) RNA during T cell activation. Analysis of mRNA expression data for melanomas in The Cancer Genome Atlas identified a significant coexpression of MYCN with CD47 and known regulators of CD8 T cell function. Thrombospondin-1 inhibited the induction of TIGIT, CD40LG, and MCL1 mRNAs following T cell activation in vitro. Increased mRNA expression of these T cell transcripts and MYCN in melanomas was associated with improved overall survival.
Assuntos
Antígeno CD47 , Melanoma , Camundongos , Animais , Antígeno CD47/metabolismo , Proteína Proto-Oncogênica N-Myc/genética , Linfócitos T CD8-Positivos , Expressão Gênica , Melanoma/genética , RNA Mensageiro/genética , Trombospondinas/genética , Microambiente TumoralRESUMO
BACKGROUND: Breast cancer is a heterogenous disease with several histological and molecular subtypes. Models that represent these subtypes are essential for translational research aimed at improving clinical strategy for targeted therapeutics. METHODS: Different combinations of genetic aberrations (Brca1 and Trp53 loss, and inhibition of proteins of the Rb family) were induced in the mammary gland by injection of adenovirus expressing Cre recombinase into the mammary ducts of adult genetically engineered mice. Mammary tumors with different genetic aberrations were classified into molecular subtypes based on expression of molecular markers and RNAseq analysis. In vitro potency assays and Western blots were used to examine their drug sensitivities. RESULTS: Induction of Brca1 and Trp53 loss in mammary ductal epithelium resulted in development of basal-like hormone receptor (HR)-negative mammary tumors. Inhibition of Rb and Trp53 loss or the combination of Rb, Trp53 and Brca1 aberrations resulted in development of luminal ductal carcinoma positive for ER, PR, and Her2 expression. HR positivity in tumors with Rb, Trp53 and Brca1 aberrations indicated that functionality of the Rb pathway rather than Brca1 status affected HR status in these models. Mammary tumor gene expression profiles recapitulated human basal-like or luminal B breast cancer signatures, but HR-positive luminal cancer models were endocrine resistant and exhibited upregulation of PI3K signaling and sensitivity to this pathway inhibition. Furthermore, both tumor subtypes were resistant to CDK4/6 inhibition. CONCLUSIONS: Examination of molecular expression profiles and drug sensitivities of tumors indicate that these breast cancer models can be utilized as a translational platform for evaluation of targeted combinations to improve chemotherapeutic response in patients that no longer respond to hormone therapy or that are resistant to CDK4/6 inhibition.
Assuntos
Neoplasias da Mama , Glândulas Mamárias Humanas , Neoplasias Mamárias Animais , Camundongos , Animais , Humanos , Feminino , Glândulas Mamárias Humanas/metabolismo , Fosfatidilinositol 3-Quinases , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias Mamárias Animais/patologia , Epitélio/metabolismo , Hormônios , Proteína BRCA1/genéticaRESUMO
A new evaluation of previously published data suggested to us that the accumulation of mutations might slow, rather than increase, as individuals age. To explain this unexpected finding, we hypothesized that normal stem cell division rates might decrease as we age. To test this hypothesis, we evaluated cell division rates in the epithelium of human colonic, duodenal, esophageal, and posterior ethmoid sinonasal tissues. In all 4 tissues, there was a significant decrease in cell division rates with age. In contrast, cell division rates did not decrease in the colon of aged mice, and only small decreases were observed in their small intestine or esophagus. These results have important implications for understanding the relationship between normal stem cells, aging, and cancer. Moreover, they provide a plausible explanation for the enigmatic age-dependent deceleration in cancer incidence in very old humans but not in mice.
Assuntos
Envelhecimento , Divisão Celular , Desaceleração , Mutação , Neoplasias/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Colo/citologia , Colo/metabolismo , Duodeno/citologia , Duodeno/metabolismo , Esôfago/citologia , Esôfago/metabolismo , Humanos , Incidência , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/patologia , Seios Paranasais/citologia , Seios Paranasais/metabolismo , Adulto JovemRESUMO
Human T cell leukemia virus type 1 (HTLV-1) is the ethological agent of adult T cell leukemia/lymphoma (ATLL) and a number of lymphocyte-mediated inflammatory conditions, including HTLV-1-associated myelopathy/tropical spastic paraparesis. HTLV-1 orf-I encodes two proteins, p8 and p12, whose functions in humans are to counteract innate and adaptive responses and to support viral transmission. However, the in vivo requirements for orf-I expression vary in different animal models. In macaques, the ablation of orf-I expression by mutation of its ATG initiation codon abolishes the infectivity of the molecular clone HTLV-1p12KO In rabbits, HTLV-1p12KO is infective and persists efficiently. We used humanized mouse models to assess the infectivity of both wild-type HTLV-1 (HTLV-1WT) and HTLV-1p12KO We found that NOD/SCID/γC-/- c-kit+ mice engrafted with human tissues 1 day after birth (designated NSG-1d mice) were highly susceptible to infection by HTLV-1WT, with a syndrome characterized by the rapid polyclonal proliferation and infiltration of CD4+ CD25+ T cells into vital organs, weight loss, and death. HTLV-1 clonality studies revealed the presence of multiple clones of low abundance, confirming the polyclonal expansion of HTLV-1-infected cells in vivo HTLV-1p12KO infection in a bone marrow-liver-thymus (BLT) mouse model prone to graft-versus-host disease occurred only following reversion of the orf-I initiation codon mutation within weeks after exposure and was associated with high levels of HTLV-1 DNA in blood and the expansion of CD4+ CD25+ T cells. Thus, the incomplete reconstitution of the human immune system in BLT mice may provide a window of opportunity for HTLV-1 replication and the selection of viral variants with greater fitness.IMPORTANCE Humanized mice constitute a useful model for studying the HTLV-1-associated polyclonal proliferation of CD4+ T cells and viral integration sites in the human genome. The rapid death of infected animals, however, appears to preclude the clonal selection typically observed in human ATLL, which normally develops in 2 to 5% of individuals infected with HTLV-1. Nevertheless, the expansion of multiple clones of low abundance in these humanized mice mirrors the early phase of HTLV-1 infection in humans, providing a useful model to investigate approaches to inhibit virus-induced CD4+ T cell proliferation.
Assuntos
Linfócitos T CD4-Positivos/virologia , Proliferação de Células , Infecções por HTLV-I/patologia , Infecções por HTLV-I/virologia , Interações Hospedeiro-Patógeno , Vírus Linfotrópico T Tipo 1 Humano/crescimento & desenvolvimento , Proteínas Virais Reguladoras e Acessórias/metabolismo , Animais , Modelos Animais de Doenças , Transmissão de Doença Infecciosa , Camundongos , Camundongos Knockout , Camundongos SCID , Proteínas Virais Reguladoras e Acessórias/deficiênciaRESUMO
The azoxymethane (AOM)/dextran sulfate sodium (DSS) murine model is commonly used to study colitis-associated cancer. The human commensal bacterium, enterotoxigenic Bacteroides fragilis (ETBF) secretes the Bacteroides fragilis toxin (BFT) which is necessary and sufficient to cause colitis. We report that BALB/c mice infected with WT-ETBF and administered three cycles of AOM/DSS developed numerous, large-sized polyps predominantly in the colorectal region. In addition, AOM/DSS-treated BALB/c mice orally inoculated with wild-type nontoxigenic Bacteroides fragilis (WT-NTBF) overexpressing bft (rETBF) developed numerous polyps whereas mice infected with WT-NTBF overexpressing a biologically inactive bft (rNTBF) did not promote polyp formation. Unexpectedly, the combination of AOM+ETBF did not induce polyp formation whereas ETBF+DSS did induce polyp development in a subset of BALB/c mice. In conclusion, WT-ETBF promoted polyp development in AOM/DSS murine model with increased colitis in BALB/c mice. The model described herein provides an experimental platform for understanding ETBF-induced colonic tumorigenesis and studying colorectal cancer in wild-type mice.
Assuntos
Infecções por Bacteroides/patologia , Carcinogênese/genética , Colite/patologia , Neoplasias Colorretais/patologia , Animais , Azoximetano/toxicidade , Toxinas Bacterianas/toxicidade , Infecções por Bacteroides/induzido quimicamente , Infecções por Bacteroides/complicações , Infecções por Bacteroides/microbiologia , Bacteroides fragilis/patogenicidade , Carcinogênese/induzido quimicamente , Colite/induzido quimicamente , Colite/complicações , Colite/microbiologia , Colo/efeitos dos fármacos , Colo/patologia , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/complicações , Neoplasias Colorretais/microbiologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Metaloendopeptidases/toxicidade , Camundongos , Pólipos/induzido quimicamenteRESUMO
Mouse kidney parvovirus (MKPV), also known as murine chapparvovirus (MuCPV), is an emerging, highly infectious agent that has been isolated from laboratory and wild mouse populations. In immunocompromised mice, MKPV produces severe chronic interstitial nephropathy and renal failure within 4 to 5 months of infection. However, the course of disease, severity of histologic lesions, and viral shedding are uncertain for immunocompetent mice. We evaluated MKPV infections in CD-1 and Swiss Webster mice, 2 immunocompetent stocks of mice. MKPV-positive CD-1 mice (n = 30) were identified at approximately 8 weeks of age by fecal PCR (polymerase chain reaction) and were subsequently housed individually for clinical observation and diagnostic sampling. Cage swabs, fecal pellets, urine, and blood were evaluated by PCR at 100 and 128 days following the initial positive test, which identified that 28 of 30 were persistently infected and 24 of these were viremic at 100 days. Histologic lesions associated with MKPV in CD-1 (n = 31) and Swiss mice (n = 11) included lymphoplasmacytic tubulointerstitial nephritis with tubular degeneration. Inclusion bodies were rare; however, intralesional MKPV mRNA was consistently detected via in situ hybridization within tubular epithelial cells of the renal cortex and within collecting duct lumina. In immunocompetent CD-1 mice, MKPV infection resulted in persistent shedding of virus for up to 10 months and a mild tubulointerstitial nephritis, raising concerns that this virus could produce study variations in immunocompetent models. Intranuclear inclusions were not a consistent feature of MKPV infection in immunocompetent mice.
Assuntos
Nefrite Intersticial , Infecções por Parvoviridae , Parvovirinae , Doenças dos Roedores , Animais , Rim , Camundongos , Camundongos Endogâmicos , Nefrite Intersticial/veterinária , Infecções por Parvoviridae/veterinária , Parvovirinae/patogenicidadeRESUMO
Nongestational choriocarcinoma is a rare malignancy in humans with poor prognosis. Naturally occurring choriocarcinoma is also rare in laboratory mice, and no genetic mouse model accurately recapitulates the features of this cancer. Here we report development of a genetically engineered mouse (GEM) model with alterations in Brca2, Trp53, and RB that develops ovarian tumors. Most of the ovarian tumors displayed histological characteristics of nongestational choriocarcinoma of the ovary (NGCO) (47%) with abundant syncytiotrophoblasts and cytotrophoblasts, positive immunolabeling for human chorionic gonadotropin, and positive periodic acid-Schiff reaction. The rest of the ovarian tumors were serous epithelial ovarian carcinoma (SEOC) (26%) or mixed tumors consisting of NGCO and SEOC (26%). We further established syngeneic orthotopic mouse models for NGCO by in vivo passaging of GEM tumors. These metastatic models provide a platform for evaluating new treatment strategies in preclinical studies aimed at improving outcomes in choriocarcinoma patients.
Assuntos
Coriocarcinoma não Gestacional/veterinária , Transplante de Neoplasias/veterinária , Neoplasias Ovarianas/veterinária , Aloenxertos , Animais , Coriocarcinoma não Gestacional/patologia , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Transgênicos , Neoplasias Ovarianas/patologia , Ovário/patologiaRESUMO
BACKGROUND: Macaques are an excellent model for many human diseases, including reproductive diseases such as endometriosis. A long-recognized need for early biomarkers of endometriosis has not yet resulted in consensus. While biomarker studies have examined many bodily fluids and targets, cervicovaginal secretions have been relatively under-investigated. Extracellular vesicles (EVs, including exosomes and microvesicles) are found in every biofluid examined, carry cargo including proteins and RNA, and may participate in intercellular signaling. Little is known about EVs in the cervicovaginal compartment, including the effects of reproductive tract disease on quantity and quality of EVs. CASE PRESENTATION: In September 2014, a 9-year-old rhesus macaque was diagnosed with endometriosis at The Johns Hopkins University School of Medicine. Ultrasound-guided fine needle aspiration of a cyst and subsequent laparotomy confirmed diagnosis. The animal was sent to necropsy following euthanasia for humane reasons. Perimortem vaginal swabs and cervicovaginal lavages were obtained. Using a combination of methods, including ultracentrifugation and NanoSight visualization technology, approximate numbers of EVs from each sample were calculated and compared to populations of EVs from other, reproductively normal macaques. Fewer EVs were recovered from the endometriosis samples as compared with those from reproductively healthy individuals. CONCLUSION: To our knowledge, this is the first examination of EVs in primate cervicovaginal secretions, including those of a macaque with endometriosis. This case study suggests that additional research is justified to determine whether quantification of EVs-or their molecular cargo-in cervicovaginal lavage and vaginal swabs may provide a novel, relatively non-invasive diagnostic for primate endometrial disease or other reproductive tract diseases.
Assuntos
Endometriose/veterinária , Vesículas Extracelulares/fisiologia , Doenças dos Macacos/diagnóstico , Animais , Biomarcadores , Endometriose/diagnóstico , Endometriose/patologia , Feminino , Macaca mulattaRESUMO
T helper 17 (TH17) cells are implicated in autoimmune diseases, and several metabolic processes are shown to be important for their development and function. In this study, we report an essential role for sphingolipids synthesized through the de novo pathway in TH17 cell development. Deficiency of SPTLC1, a major subunit of serine palmitoyl transferase enzyme complex that catalyzes the first and rate-limiting step of de novo sphingolipid synthesis, impaired glycolysis in differentiating TH17 cells by increasing intracellular reactive oxygen species (ROS) through enhancement of nicotinamide adenine dinucleotide phosphate oxidase 2 activity. Increased ROS leads to impaired activation of mammalian target of rapamycin C1 and reduced expression of hypoxia-inducible factor 1-alpha and c-Myc-induced glycolytic genes. SPTLCI deficiency protected mice from developing experimental autoimmune encephalomyelitis and experimental T cell transfer colitis. Our results thus show a critical role for de novo sphingolipid biosynthetic pathway in shaping adaptive immune responses with implications in autoimmune diseases.
Assuntos
Diferenciação Celular , Encefalomielite Autoimune Experimental , Serina C-Palmitoiltransferase , Esfingolipídeos , Células Th17 , Animais , Esfingolipídeos/metabolismo , Esfingolipídeos/biossíntese , Células Th17/imunologia , Células Th17/metabolismo , Células Th17/citologia , Camundongos , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/imunologia , Serina C-Palmitoiltransferase/metabolismo , Serina C-Palmitoiltransferase/genética , Espécies Reativas de Oxigênio/metabolismo , Glicólise , Camundongos Knockout , Colite/metabolismo , Colite/patologia , Camundongos Endogâmicos C57BLRESUMO
Disruption of DNA damage repair via impaired homologous recombination is characteristic of Ewing sarcoma (EWS) cells. We hypothesize that this disruption results in increased reliance on nonhomologous end joining to repair DNA damage. In this study, we investigated if pharmacologic inhibition of the enzyme responsible for nonhomologous end joining, the DNA-PK holoenzyme, alters the response of EWS cells to genotoxic standard of care chemotherapy. We used analyses of cell viability and proliferation to investigate the effects of clinical DNA-PK inhibitors (DNA-PKi) in combination with six therapeutic or experimental agents for EWS. We performed calculations of synergy using the Loewe additivity model. Immunoblotting evaluated treatment effects on DNA-PK, DNA damage, and apoptosis. Flow cytometric analyses evaluated effects on cell cycle and fate. We used orthotopic xenograft models to interrogate tolerability, drug mechanism, and efficacy in vivo. DNA-PKi demonstrated on-target activity, reducing phosphorylated DNA-PK levels in EWS cells. DNA-PKi sensitized EWS cell lines to agents that function as topoisomerase 2 (TOP2) poisons and enhanced the DNA damage induced by TOP2 poisons. Nanomolar concentrations of single-agent TOP2 poisons induced G2M arrest and little apoptotic response while adding DNA-PKi-mediated apoptosis. In vivo, the combination of AZD7648 and etoposide had limited tolerability but resulted in enhanced DNA damage, apoptosis, and EWS tumor shrinkage. The combination of DNA-PKi with standard of care TOP2 poisons in EWS models is synergistic, enhances DNA damage and cell death, and may form the basis of a promising future therapeutic strategy for EWS.
Assuntos
Proteína Quinase Ativada por DNA , Sarcoma de Ewing , Animais , Humanos , Camundongos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dano ao DNA , Proteína Quinase Ativada por DNA/antagonistas & inibidores , Proteína Quinase Ativada por DNA/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/patologia , Padrão de Cuidado , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Glioblastoma (GBM) is hard to treat due to cellular invasion into functioning brain tissues, limited drug delivery, and evolved treatment resistance. Recurrence is nearly universal even after surgery, chemotherapy, and radiation. Photodynamic therapy (PDT) involves photosensitizer administration followed by light activation to generate reactive oxygen species at tumor sites, thereby killing cells or inducing biological changes. PDT can ablate unresectable GBM and sensitize tumors to chemotherapy. Verteporfin (VP) is a promising photosensitizer that relies on liposomal carriers for clinical use. While lipids increase VP's solubility, they also reduce intracellular photosensitizer accumulation. Here, a pure-drug nanoformulation of VP, termed "NanoVP", eliminating the need for lipids, excipients, or stabilizers is reported. NanoVP has a tunable size (65-150 nm) and 1500-fold higher photosensitizer loading capacity than liposomal VP. NanoVP shows a 2-fold increase in photosensitizer uptake and superior PDT efficacy in GBM cells compared to liposomal VP. In mouse models, NanoVP-PDT improved tumor control and extended animal survival, outperforming liposomal VP and 5-aminolevulinic acid (5-ALA). Moreover, low-dose NanoVP-PDT can safely open the blood-brain barrier, increasing drug accumulation in rat brains by 5.5-fold compared to 5-ALA. NanoVP is a new photosensitizer formulation that has the potential to facilitate PDT for the treatment of GBM.
Assuntos
Neoplasias Encefálicas , Sistemas de Liberação de Medicamentos , Fotoquimioterapia , Fármacos Fotossensibilizantes , Verteporfina , Animais , Fotoquimioterapia/métodos , Verteporfina/farmacologia , Verteporfina/uso terapêutico , Camundongos , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Glioblastoma/tratamento farmacológico , Nanopartículas/química , Modelos Animais de Doenças , Humanos , Ratos , Lipossomos , Linhagem Celular Tumoral , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacosRESUMO
In malignant glioma, cytotoxic drugs are often inhibited from accessing the tumor site due to the blood-tumor barrier (BTB). Ibrutinib, FDA-approved lymphoma agent, inhibits Bruton tyrosine kinase (BTK) and has previously been shown to independently impair aortic endothelial adhesion and increase rodent glioma model survival in combination with cytotoxic therapy. Yet additional research is required to understand ibrutinib's effect on BTB function. In this study, we detail baseline BTK expression in glioma cells and its surrounding vasculature, then measure endothelial junctional expression/function changes with varied ibrutinib doses in vitro. Rat glioma cells and rodent glioma models were treated with ibrutinib alone (1-10 µM and 25 mg/kg) and in combination with doxil (10-100 µM and 3 mg/kg) to assess additive effects on viability, drug concentrations, tumor volume, endothelial junctional expression and survival. We found that ibrutinib, in a dose-dependent manner, decreased brain endothelial cell-cell adhesion over 24 h, without affecting endothelial cell viability (p < 0.005). Expression of tight junction gene and protein expression was decreased maximally 4 h after administration, along with inhibition of efflux transporter, ABCB1, activity. We demonstrated an additive effect of ibrutinib with doxil on rat glioma cells, as seen by a significant reduction in cell viability (p < 0.001) and increased CNS doxil concentration in the brain (56 ng/mL doxil alone vs. 74.6 ng/mL combination, p < 0.05). Finally, Ibrutinib, combined with doxil, prolonged median survival in rodent glioma models (27 vs. 16 days, p < 0.0001) with brain imaging showing a - 53% versus - 75% volume change with doxil alone versus combination therapy (p < 0.05). These findings indicate ibrutinib's ability to increase brain endothelial permeability via junctional disruption and efflux inhibition, to increase BTB drug entry and prolong rodent glioma model survival. Our results motivate the need to identify other BTB modifiers, all with the intent of improving survival and reducing systemic toxicities.
Assuntos
Adenina/análogos & derivados , Antineoplásicos , Doxorrubicina/análogos & derivados , Glioma , Piperidinas , Ratos , Animais , Roedores , Glioma/patologia , Antineoplásicos/uso terapêutico , Barreira Hematoencefálica/patologia , PolietilenoglicóisRESUMO
Small-cell lung cancer (SCLC) is the most fatal form of lung cancer. Intratumoral heterogeneity, marked by neuroendocrine (NE) and non-neuroendocrine (non-NE) cell states, defines SCLC, but the cell-extrinsic drivers of SCLC plasticity are poorly understood. To map the landscape of SCLC tumor microenvironment (TME), we apply spatially resolved transcriptomics and quantitative mass spectrometry-based proteomics to metastatic SCLC tumors obtained via rapid autopsy. The phenotype and overall composition of non-malignant cells in the TME exhibit substantial variability, closely mirroring the tumor phenotype, suggesting TME-driven reprogramming of NE cell states. We identify cancer-associated fibroblasts (CAFs) as a crucial element of SCLC TME heterogeneity, contributing to immune exclusion, and predicting exceptionally poor prognosis. Our work provides a comprehensive map of SCLC tumor and TME ecosystems, emphasizing their pivotal role in SCLC's adaptable nature, opening possibilities for reprogramming the TME-tumor communications that shape SCLC tumor states.
Assuntos
Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Microambiente Tumoral , Humanos , Carcinoma de Pequenas Células do Pulmão/patologia , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Tumores Neuroendócrinos/patologia , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/metabolismo , Células Neuroendócrinas/patologia , Células Neuroendócrinas/metabolismo , Feminino , Masculino , PrognósticoRESUMO
BACKGROUND: Colorectal cancer (CRC) is the second leading cause of death from cancer in the United States. Colorectal cancers have a prolonged latency following initiation that may span decades providing ample time for implementing a chemoprevention strategy that could block or reverse the progression to CRC. Cdk4 pathway alterations have been linked to a number of cancers including CRC. In these experiments we focused on the Cdk4 pathway and its role in intestinal tumorigenesis as a possible target in chemoprevention strategies. METHODS: We evaluated the effect of Cdk4 blockade on the prevention of intestinal tumor formation by crossing Cdk4(-/-) mice to Apc(-/+) mice. In addition, we tested the effect of the dietary compound silibinin on the Cdk4 pathway in Apc(-/+) mice and HT-29 colon cancer cells in culture. RESULTS: Cdk4(-/-) mice backcrossed to Apc(-/+) mice reduced intestinal adenoma formation compared to Apc(-/+) controls. Silibinin effectively targeted the Cdk4 pathway causing hypophosphorylation of the retinoblastoma protein, inhibited cell growth, and induced apoptosis. As a result silibinin blocked the development of intestinal adenomas by 52% in this genetic model (Apc(-/+) mice) of early events in colorectal cancer formation. No toxic abnormalities were detected in mice which received silibinin. CONCLUSIONS: Modification of the Cdk4 pathway using a natural plant-derived compound such as silibinin may be a useful chemopreventive strategy for colorectal carcinomas.
Assuntos
Quinase 4 Dependente de Ciclina/metabolismo , Genes APC , Transdução de Sinais/efeitos dos fármacos , Silimarina/farmacologia , Adenoma/genética , Adenoma/metabolismo , Adenoma/patologia , Adenoma/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quimioprevenção , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/prevenção & controle , Ciclina D1/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Knockout , Proteína do Retinoblastoma/metabolismo , Silibina , Silimarina/uso terapêuticoRESUMO
The pathway involving the tumor suppressor gene TP53 can regulate tumor angiogenesis by unclear mechanisms. Here we show that p53 regulates hypoxic signaling through the transcriptional regulation of microRNA-107 (miR-107). We found that miR-107 is a microRNA expressed by human colon cancer specimens and regulated by p53. miR-107 decreases hypoxia signaling by suppressing expression of hypoxia inducible factor-1beta (HIF-1beta). Knockdown of endogenous miR-107 enhances HIF-1beta expression and hypoxic signaling in human colon cancer cells. Conversely, overexpression of miR-107 inhibits HIF-1beta expression and hypoxic signaling. Furthermore, overexpression of miR-107 in tumor cells suppresses tumor angiogenesis, tumor growth, and tumor VEGF expression in mice. Finally, in human colon cancer specimens, expression of miR-107 is inversely associated with expression of HIF-1beta. Taken together these data suggest that miR-107 can mediate p53 regulation of hypoxic signaling and tumor angiogenesis.
Assuntos
Translocador Nuclear Receptor Aril Hidrocarboneto/metabolismo , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Neovascularização Patológica/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Sequência de Bases , Hipóxia Celular , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Neoplasias/genética , Neoplasias/patologia , Neovascularização Patológica/genética , Transdução de Sinais , Transcrição Gênica , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Cholangiocarcinoma (CCA) is a heterogenous malignancy that arises from the biliary epithelium and has a poor clinical prognosis. The Hippo/yes-associated protein (YAP) pathway has been reported to affect various aspects of tumorigenesis, with high expression of YAP1 being negatively associated with survival in CCA patients. Thus, we investigated the antitumoral effect of verteporfin, a YAP1 pathway inhibitor, in YAP1/AKT hydrodynamic tail vein injected murine models. We also used flow cytometry and single-cell RNA sequencing (scRNA-seq) to analyze the change in the immune cell profile and malignant cell stemness following verteporfin treatment. Our results demonstrated reduced liver weight and tumor formation in verteporfin-treated groups compared to that of a vehicle-treated group. Immune cell profiling through flow cytometry showed that relative to the vehicle, verteporfin induced a higher ratio of tumor-associated macrophage (TAM) M1/M2 and increased the percentage of activated CD8 T cell population (CD8+CD25+ and CD8+CD69+). scRNA-seq analysis showed significantly increased TAM M1 populations following verteporfin treatment and decreased proportions of stem-like cells within the malignant cell population. In summary, this study indicates that in CCA YAP/AKT murine models, verteporfin reduces tumorigenesis by polarizing anti-tumoral TAM and activating CD8 T cells and decreasing stem-like malignant cell proportions in the tumor microenvironment.