RESUMEN
Although low estrogen is considered to suppress uterine endometrial carcinoma, the most cases occur in the postmenopausal stage. After menopause, the production of androgen level also declines. Therefore, to resolve the above enigma, we hypothesize that the postmenopausal decline of androgen is a trigger of its progression. In the present study, to validate this hypothesis, we examine the pathological roles of androgen/AR by analyzing clinical data, culturing endometrioid cancer cell lines, and using murine models. Clinical data show that androgen receptor (AR) expression and serum dihydrotestosterone (DHT) are associated with lower disease-free survival (DFS). DHT suppresses malignant behaviors in AR-transfected human endometrial cancer cells (ECC). In ovariectomized Ptenff/PRcre/+ mice, DHT decreases the proliferation of spontaneously developed murine ECC. In AR-transfected human ECC and Ptenff/PRcre/+ mice, DHT suppresses FOXP4 expression. FOXP4-overexpressed human ECC increases, while FOXP4-knocked-down ECC shows decreased malignant behaviors. DHT/AR-mediated ECC suppression is restored by FOXP4 overexpression. The high FOXP4 expression is significantly correlated with low postoperative DFS. These findings indicate that the androgen/AR system suppresses the malignant activity of endometrial carcinoma and that downstream FOXP4 is another target molecule. These findings will also impact developments in clinical approaches to elderly health.
Asunto(s)
Andrógenos , Neoplasias Endometriales , Factores de Transcripción Forkhead , Receptores Androgénicos , Femenino , Neoplasias Endometriales/metabolismo , Neoplasias Endometriales/genética , Humanos , Animales , Ratones , Factores de Transcripción Forkhead/metabolismo , Factores de Transcripción Forkhead/genética , Receptores Androgénicos/metabolismo , Receptores Androgénicos/genética , Andrógenos/metabolismo , Línea Celular Tumoral , Dihidrotestosterona/metabolismo , Dihidrotestosterona/farmacología , Regulación Neoplásica de la Expresión Génica , Persona de Mediana Edad , Proliferación CelularRESUMEN
RECK has been described to modulate extracellular matrix components through negative regulation of MMP activities. Recently, RECK was demonstrated to bind to an orphan G protein-coupled receptor GPR124 to mediate WNT7 signaling in nontumor contexts. Here, we attempted to clarify the role of RECK in driving WNT signaling in cancer cells. RECK and GPR124 formed a complex in 293T cells, and when both were expressed, WNT signaling was significantly enhanced in a WNT7-dependent manner. This cooperation was abolished when RECK mutants unable to bind to GPR124 were transduced. RECK stimulated the growth of KRAS-mutated pancreatic ductal adenocarcinoma (PDAC) cells with increased sensitivity to WNT inhibitor in a GPR124-dependent manner. A gastric cancer cell line SH10TC endogenously expresses both RECK and GPR124 under regular culture conditions. In this cell line, inhibited cell growth and WNT signaling as well as increased apoptosis in the GPR124 depletion was dominantly found over those in the RECK deletion. These findings suggest that RECK promotes tumor cell growth by positively modulating WNT signaling through GPR124. This study proposes that the RECK/GPR124 complex might be a good therapeutic target in PDAC and gastric cancer.
RESUMEN
While loss of function (LOF) of retinoblastoma 1 (RB1) tumor suppressor is known to drive initiation of small-cell lung cancer and retinoblastoma, RB1 mutation is rarely observed in breast cancers at their initiation. In this study, we investigated the impact on untransformed mammary epithelial cells given by RB1 LOF. Depletion of RB1 in anon-tumorigenic MCF10A cells induced reversible growth arrest (quiescence) featured by downregulation of multiple cyclins and MYC, upregulation of p27KIP1, and lack of expression of markers which indicate cellular senescence or epithelial-mesenchymal transition (EMT). We observed a similar phenomenon in human mammary epithelial cells (HMEC) as well. Additionally, we found that RB1 depletion attenuated the activity of RAS and the downstream MAPK pathway in an RBL2/p130-dependent manner. The expression of farnesyltransferase ß, which is essential for RAS maturation, was found to be downregulated following RB1 depletion also in an RBL2/p130-dependent manner. These findings unveiled an unexpected mechanism whereby normal mammary epithelial cells resist to tumor initiation upon RB1 LOF.
Asunto(s)
Regulación hacia Abajo , Células Epiteliales , Proteínas de Unión a Retinoblastoma , Transducción de Señal , Proteínas ras , Humanos , Células Epiteliales/metabolismo , Femenino , Proteínas de Unión a Retinoblastoma/metabolismo , Proteínas de Unión a Retinoblastoma/genética , Proteínas ras/metabolismo , Proteínas ras/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/genética , Transición Epitelial-Mesenquimal/genética , Glándulas Mamarias Humanas/metabolismo , Glándulas Mamarias Humanas/patología , Glándulas Mamarias Humanas/citología , Línea Celular Tumoral , Proteína de Retinoblastoma/metabolismo , Proteína de Retinoblastoma/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genéticaRESUMEN
Two splicing variants exist in NFYA that exhibit high expression in many human tumour types. The balance in their expression correlates with prognosis in breast cancer, but functional differences remain unclear. Here, we demonstrate that NFYAv1, a long-form variant, upregulates the transcription of essential lipogenic enzymes ACACA and FASN to enhance the malignant behavior of triple-negative breast cancer (TNBC). Loss of the NFYAv1-lipogenesis axis strongly suppresses malignant behavior in vitro and in vivo, indicating that the NFYAv1-lipogenesis axis is essential for TNBC malignant behavior and that the axis might be a potential therapeutic target for TNBC. Furthermore, mice deficient in lipogenic enzymes, such as Acly, Acaca, and Fasn, exhibit embryonic lethality; however, Nfyav1-deficient mice exhibited no apparent developmental abnormalities. Our results indicate that the NFYAv1-lipogenesis axis has tumour-promoting effects and that NFYAv1 may be a safe therapeutic target for TNBC.
Asunto(s)
Neoplasias de la Mama Triple Negativas , Humanos , Animales , Ratones , Neoplasias de la Mama Triple Negativas/metabolismo , Metabolismo de los Lípidos/genética , Línea Celular Tumoral , Pronóstico , Lipogénesis , Factor de Unión a CCAAT/metabolismoRESUMEN
Drug resistance limits the efficacy of chemotherapy and targeted cancer treatments, calling for the identification of druggable targets to overcome it. Here we show that the mitochondria-shaping protein Opa1 participates in resistance against the tyrosine kinase inhibitor gefitinib in a lung adenocarcinoma cell line. Respiratory profiling revealed that oxidative metabolism was increased in this gefitinib-resistant lung cancer cell line. Accordingly, resistant cells depended on mitochondrial ATP generation, and their mitochondria were elongated with narrower cristae. In the resistant cells, levels of Opa1 were increased and its genetic or pharmacological inhibition reverted the mitochondrial morphology changes and sensitized them to gefitinib-induced cytochrome c release and apoptosis. In vivo, the size of gefitinib-resistant lung orthotopic tumors was reduced when gefitinib was combined with the specific Opa1 inhibitor MYLS22. The combo gefitinib-MYLS22 treatment increased tumor apoptosis and reduced its proliferation. Thus, the mitochondrial protein Opa1 participates in gefitinib resistance and can be targeted to overcome it.
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Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Gefitinib/farmacología , Carcinoma de Pulmón de Células no Pequeñas/patología , Resistencia a Antineoplásicos , Línea Celular Tumoral , Neoplasias Pulmonares/patología , Inhibidores de Proteínas Quinasas/farmacología , Mitocondrias/metabolismo , Pulmón/metabolismo , Proliferación Celular , Apoptosis , Antineoplásicos/farmacología , GTP Fosfohidrolasas/metabolismoRESUMEN
T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of immature T lymphocytes. Although various therapeutic approaches have been developed, refractoriness of chemotherapy and relapse cause a poor prognosis of the disease and further therapeutic strategies are required. Here, we report that Ras homolog enriched in brain (RHEB), a critical regulator of mTOR complex 1 activity, is a potential target for T-ALL therapy. In this study, we established an sgRNA library that comprehensively targeted mTOR upstream and downstream pathways, including autophagy. CRISPR/Cas9 dropout screening revealed critical roles of mTOR-related molecules in T-ALL cell survival. Among the regulators, we focused on RHEB because we previously found that it is dispensable for normal hematopoiesis in mice. Transcriptome and metabolic analyses revealed that RHEB deficiency suppressed de novo nucleotide biosynthesis, leading to human T-ALL cell death. Importantly, RHEB deficiency suppressed tumor growth in both mouse and xenograft models. Our data provide a potential strategy for efficient therapy of T-ALL by RHEB-specific inhibition.
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Leucemia-Linfoma Linfoblástico de Células T Precursoras , Proteína Homóloga de Ras Enriquecida en el Cerebro , Animales , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteína Homóloga de Ras Enriquecida en el Cerebro/genética , Proteína Homóloga de Ras Enriquecida en el Cerebro/metabolismo , Transducción de Señal , Linfocitos T/metabolismo , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Reactive oxygen species (ROS) activate uncoupler protein 1 (UCP1) in brown adipose tissue (BAT) under physiological cold exposure and noradrenaline (NA) stimulation to increase thermogenesis. However, the endogenous regulator of ROS in activated BAT and its role in pathological conditions remain unclear. We show that serum levels of selenoprotein P (SeP; encoded by SELENOP) negatively correlate with BAT activity in humans. Physiological cold exposure downregulates Selenop in BAT. Selenop knockout mice show higher rectal temperatures and UCP1 sulfenylation during cold exposure. SeP treatment to brown adipocytes eliminated the NA-induced mitochondrial ROS by upregulating glutathione peroxidase 4 and impaired cellular thermogenesis. A high-fat/high-sucrose diet elevates serum SeP levels and diminishes the elevated NA-induced thermogenesis in BAT-Selenop KO mice. Therefore, SeP is the intrinsic factor inducing reductive stress that impairs thermogenesis in BAT and may be a potential therapeutic target for obesity and diabetes.
Asunto(s)
Tejido Adiposo Pardo , Selenoproteína P , Adipocitos Marrones , Tejido Adiposo Pardo/metabolismo , Animales , Dieta Alta en Grasa , Ratones , Selenoproteína P/metabolismo , Termogénesis/fisiologíaRESUMEN
We previously isolated derrisfolin A, a novel rotenoid derivative, from the stems of Derris trifoliata Lour. (Leguminosae). Here, we report that derrisfolin A induces the expression of endogenous regucalcin (RGN) protein in both pancreatic MIN6 ß-cells and RAW264.7 macrophages. Induction of RGN expression by derrisfolin A or retrovirus-mediated gene transfer in MIN6 cells and RAW264.7 macrophages significantly decreased lipopolysaccharide (LPS)-induced mRNA expression of Nos2, Il1b, and Tnf via nuclear factor-κB activation; reduced LPS-induced apoptosis in MIN6 cells, accompanied by decreased production of nitric oxide, interleukin-1ß, and tumor necrosis factor-α; and attenuated generation of LPS-induced reactive oxygen species, malondialdehyde, and 3-nitrotyrosine in MIN6 cells. Additionally, in co-cultures of MIN6 cells with RAW264.7 macrophages in the presence of LPS, induction of RGN expression by derrisfolin A or retrovirus-mediated gene transfer in RAW264.7 macrophages attenuated apoptosis and oxidative/nitrosative stress in MIN6 cells. These results suggest that the induction of RGN expression in MIN6 cells was effective in suppressing LPS-induced inflammatory cytotoxicity and that in co-culture conditions, the induction of RGN expression in RAW264.7 macrophages blocked LPS-induced paracrine effects of RAW264.7 macrophages on inflammatory cytotoxicity in MIN6 cells. Our findings suggest that derrisfolin A, a chemical inducer of RGN, might be useful for developing a new drug against macrophage-associated ß-cell inflammation in type 2 diabetes.
Asunto(s)
Diabetes Mellitus Tipo 2 , Lipopolisacáridos , Animales , Diabetes Mellitus Tipo 2/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/metabolismo , Ratones , FN-kappa B/metabolismo , Células RAW 264.7RESUMEN
Retinoblastoma protein 1 (RB1) is encoded by a tumor suppressor gene that was discovered more than 30 years ago. Almost all mitogenic signals promote cell cycle progression by braking on the function of RB1 protein through mono- and subsequent hyper-phosphorylation mediated by cyclin-CDK complexes. The loss of RB1 function drives tumorigenesis in limited types of malignancies including retinoblastoma and small cell lung cancer. In a majority of human cancers, RB1 function is suppressed during tumor progression through various mechanisms. The latter gives rise to the acquisition of various phenotypes that confer malignant progression. The RB1-targeted molecules involved in such phenotypic changes are good quarries for cancer therapy. Indeed, a variety of novel therapies have been proposed to target RB1 loss. In particular, the inhibition of a number of mitotic kinases appeared to be synthetic lethal with RB1 deficiency. A recent study focusing on a neighboring gene that is often collaterally deleted together with RB1 revealed a pharmacologically targetable vulnerability in RB1-deficient cancers. Here we summarize current understanding on possible therapeutic approaches targeting functional or genomic aberration of RB1 in cancers.
RESUMEN
BACKGROUND AND AIMS: Synthetic cyclin-dependent kinase (CDK) 4/6 inhibitors exert antitumor effects by forcing RB1 in unphosphorylated status, causing not only cell cycle arrest but also cellular senescence, apoptosis, and increased immunogenicity. These agents currently have an indication in advanced breast cancers and are in clinical trials for many other solid tumors. HCC is one of promising targets of CDK4/6 inhibitors. RB family dysfunction is often associated with the initiation of HCC; however, this is revivable, as RB family members are not frequently mutated or deleted in this malignancy. APPROACH AND RESULTS: Loss of all Rb family members in transformation related protein 53 (Trp53)-/- mouse liver resulted in liver tumor reminiscent of human HCC, and re-expression of RB1 sensitized these tumors to a CDK4/6 inhibitor, palbociclib. Introduction of an unphosphorylatable form of RB1 (RB7LP) into multiple liver tumor cell lines induced effects similar to palbociclib. By screening for compounds that enhance the efficacy of RB7LP, we identified an I kappa B kinase (IKK)ß inhibitor Bay 11-7082. Consistently, RB7LP expression and treatment with palbociclib enhanced IKKα/ß phosphorylation and NF-κB activation. Combination therapy using palbociclib with Bay 11-7082 was significantly more effective in hepatoblastoma and HCC treatment than single administration. Moreover, blockade of IKK-NF-κB or AKT pathway enhanced effects of palbociclib on RB1-intact KRAS Kirsten rat sarcoma viral oncogene homolog mutated lung and colon cancers. CONCLUSIONS: In conclusion, CDK4/6 inhibitors have a potential to treat a wide variety of RB1-intact cancers including HCC when combined with an appropriate kinase inhibitor.
Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Proliferación Celular/efectos de los fármacos , Neoplasias Hepáticas/tratamiento farmacológico , Piperazinas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Aminopiridinas/farmacología , Aminopiridinas/uso terapéutico , Animales , Bencimidazoles/farmacología , Bencimidazoles/uso terapéutico , Carcinoma Hepatocelular/genética , Proliferación Celular/genética , Supervivencia Celular/efectos de los fármacos , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Células Hep G2 , Humanos , Técnicas In Vitro , Neoplasias Hepáticas/genética , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/genética , Ratones , Trasplante de Neoplasias , Piperazinas/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Purinas/farmacología , Purinas/uso terapéutico , Piridinas/uso terapéutico , Proteína de Retinoblastoma , Proteína p53 Supresora de Tumor/genética , Proteínas de XenopusRESUMEN
Autophagy is a cellular degradation system contributing to homeostasis of tissue stem cells including haematopoietic stem cells (HSCs). It plays pleiotropic roles in HSC characteristics throughout life, but its stage-specific roles in HSC self-renewal are unclear. To investigate the effects of Atg5 deletion on stage-specific HSC functions, we compared the repopulating capacity of HSCs in Atg5f/f;Vavi-cre mice from postnatal day (P) 0-7 weeks of age. Interestingly, Atg5 deficiency led to no remarkable abnormality in the HSC self-renewal capacity at P0, but significant defects at P7, followed by severe defects. Induction of Atg5 deletion at P5 by tamoxifen administration to Atg5f/f;Rosa26-Cre-ERT2 mice resulted in normal haematopoiesis, including the HSC population, until around 1 year, suggesting that Atg5 in the early neonatal period was critical for haematopoiesis in adults. Mitochondrial oxidative stress was increased by Atg5 loss in neonatal HSC/progenitor cells. Although p62 had accumulated in immature bone marrow cells of Atg5f/f;Vavi-cre mice, p62 deletion did not restore defective HSC functions, indicating that Atg5-dependent haematopoietic regulation in the developmental period was independent of p62. This study proposes a critical role of autophagy in HSC protection against harsh environments in the early neonatal stage, which is essential for healthy long-term haematopoiesis.
Asunto(s)
Proteína 5 Relacionada con la Autofagia/metabolismo , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Proteína Sequestosoma-1/metabolismo , Animales , Animales Recién Nacidos , Autofagia/fisiología , Proteína 5 Relacionada con la Autofagia/genética , Modelos Animales de Enfermedad , Femenino , Células Madre Hematopoyéticas/patología , Masculino , Ratones , Ratones Noqueados , Estrés Oxidativo/fisiologíaRESUMEN
Dysregulation of adipocyte differentiation and dysfunction play key roles in the pathogenesis of obesity and associated disorders such as diabetes and metabolic syndrome, and as such, a better understanding of the molecular mechanism of adipogenesis may help to elucidate the pathological condition of obesity and its associated disorders. Regucalcin (RGN) plays multiple regulatory roles in intracellular Ca2+ signaling pathways in mammalian cells. Here, we report that overexpression of RGN enhances lipid accumulation in 3T3-L1 adipocyte cells after adipogenic stimulation, accompanied by upregulation of adipocyte differentiation marker proteins. In contrast, genetic disruption of RGN inhibited adipogenic stimulation-induced differentiation of 3T3-L1 cells. Furthermore, RGN overexpression in differentiated 3T3-L1 adipocytes blocked inflammatory crosstalk between 3T3-L1 adipocytes and RAW264.7 macrophages in a transwell coculture system. Knockdown of RGN expression in cocultured 3T3-L1 adipocytes enhanced their susceptibility to RAW264.7 macrophage-mediated inflammation. These results suggest that RGN is required for 3T3-L1 adipocyte differentiation and that it exerts anti-inflammatory activity against 3T3-L1 adipocyte inflammation after coculture with RAW264.7 macrophages. Thus, RGN may be a novel regulator of adipocyte differentiation and act as a suppressor of inflammation in macrophage-infiltrated adipocyte tissue.
Asunto(s)
Adipocitos/metabolismo , Proteínas de Unión al Calcio/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Células 3T3-L1 , Adipocitos/citología , Adipocitos/fisiología , Adipogénesis/genética , Adipogénesis/fisiología , Animales , Proteínas de Unión al Calcio/fisiología , Diferenciación Celular/fisiología , Línea Celular , Técnicas de Cocultivo , Inflamación/metabolismo , Péptidos y Proteínas de Señalización Intracelular/fisiología , Macrófagos/metabolismo , Ratones , Obesidad/metabolismo , Células RAW 264.7 , Transducción de Señal/efectos de los fármacosRESUMEN
RB1 gene is often homozygously deleted or mutated in prostate adenocarcinomas following acquirement of castration resistance and/or metastatic ability. We found that SUCLA2 gene is frequently involved in the deletion of the RB1 gene region in advanced prostate cancer. SUCLA2 constitutes the ß-subunit of succinate CoA ligase heterodimer that reversibly converts succinyl CoA into succinate. We sought the possibility that deletion of SUCLA2 gives rise to a metabolic vulnerability that could be targeted therapeutically. We found a significant metabolic shift in SUCLA2-deleted prostate cancer cells, including lower mitochondrial respiratory activity. By screening a number of libraries for compounds that induce cell death selectively in SUCLA2-deficient prostate cancer cells, we identified thymoquinone (2-isopropyl-5-methylbenzo-1,4-quinone) and PMA (phorbol-12-myristate-13-acetate) from a natural compound library. These findings indicate that the metabolic vulnerability in SUCLA2-deficient prostate cancer cells is pharmacologically targetable.
Asunto(s)
Eliminación de Gen , Neoplasias de la Próstata/genética , Proteína de Retinoblastoma/genética , Succinato-CoA Ligasas/genética , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Benzoquinonas/farmacología , Línea Celular Tumoral , Células HEK293 , Humanos , Masculino , Ratones Noqueados , Ratones Desnudos , Ratones SCID , Células PC-3 , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteína de Retinoblastoma/deficiencia , Succinato-CoA Ligasas/deficiencia , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
OBJECTIVES: Acridone alkaloids from Citrus and their derivatives show various kinds of biological activity. However, the anticancer activities of dimeric acridone alkaloids with unique structures and the molecular mechanism of these effects are poorly understood. METHODS: We investigated the cytotoxicity effects of dimeric acridone alkaloids isolated from Marsh grapefruit on human myeloid leukaemia HL-60 cells. KEY FINDINGS: Of the six dimeric acridone alkaloids tested, citbismine-E, the most potent, dose- and time-dependently decreased HL-60 cell viability by inducing apoptosis. The treatment of HL-60 cells with citbismine-E yielded a significant increase in levels of intracellular reactive oxygen species (ROS). Citbismine-E lowered the mitochondrial membrane potential and increased the activities of caspase-9 and -3. In addition, citbismine-E-induced apoptosis, decrease in mitochondrial membrane potential and caspase activation were significantly alleviated by pretreatment of the cells with antioxidant N-acetylcysteine (NAC). Citbismine-E induced intrinsic caspase-dependent apoptosis through ROS-mediated c-Jun N-terminal kinase activation. Citbismine-E-induced production of oxidative stress biomarkers, malondialdehyde and 8-hydroxy-2'-deoxyguanosine was also attenuated by pretreatment with NAC. CONCLUSIONS: Citbismine-E is a powerful cytotoxic agent against HL-60 cells that acts by inducing mitochondrial dysfunction-mediated apoptosis through ROS-dependent JNK activation. Citbismine-E also induced oxidative stress damage via ROS-mediated lipid peroxidation and DNA damage in HL-60 cells.
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Acridonas/uso terapéutico , Alcaloides/uso terapéutico , Antineoplásicos Fitogénicos/uso terapéutico , Citrus paradisi , Leucemia/metabolismo , Extractos Vegetales/uso terapéutico , Acridonas/aislamiento & purificación , Acridonas/farmacología , Alcaloides/aislamiento & purificación , Alcaloides/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Citotoxinas , Relación Dosis-Respuesta a Droga , Células HL-60 , Humanos , Leucemia/tratamiento farmacológico , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacologíaRESUMEN
Dietary fat consumption during accelerated stages of mammary gland development, such as peripubertal maturation or pregnancy, is known to increase the risk for breast cancer. However, the underlying molecular mechanisms are not fully understood. Here we examined the gene expression profile of mouse mammary epithelial cells (MMECs) on exposure to a high-fat diet (HFD) or control diet (CD). Trp53-/- female mice were fed with the experimental diets for 5 weeks during the peripubertal period (3-8 weeks of age). The treatment showed no significant difference in body weight between the HFD-fed mice and CD-fed mice. However, gene set enrichment analysis predicted a significant enrichment of c-Myc target genes in animals fed HFD. Furthermore, we detected enhanced activity and stabilization of c-Myc protein in MMECs exposed to a HFD. This was accompanied by augmented c-Myc phosphorylation at S62 with a concomitant increase in ERK phosphorylation. Moreover, MMECs derived from HFD-fed Trp53-/- mouse showed increased colony- and sphere-forming potential that was dependent on c-Myc. Further, oleic acid, a major fatty acid constituent of the HFD, and TAK-875, an agonist to G protein-coupled receptor 40 (a receptor for oleic acid), enhanced c-Myc stabilization and MMEC proliferation. Overall, our data indicate that HFD influences MMECs by stabilizing an oncoprotein, pointing to a novel mechanism underlying dietary fat-mediated mammary carcinogenesis.
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Dieta Alta en Grasa , Epitelio/metabolismo , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Maduración Sexual , Animales , Línea Celular Tumoral , Femenino , Genes p53 , Humanos , Ratones , Ratones Noqueados , Obesidad/etiología , Obesidad/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Pubertad , Células Tumorales CultivadasRESUMEN
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.
Asunto(s)
Quimiocina CCL2/metabolismo , Proteína de Retinoblastoma/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Técnicas de Cultivo de Célula , Línea Celular Tumoral , Quimiocina CCL2/biosíntesis , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores CCR2/metabolismo , Proteína de Retinoblastoma/deficiencia , Neoplasias de los Tejidos Blandos/metabolismo , Neoplasias de los Tejidos Blandos/patología , Microambiente Tumoral , Regulación hacia ArribaRESUMEN
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.
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Aminohidrolasas/metabolismo , Resistencia a Antineoplásicos/fisiología , Gefitinib/farmacología , Redes y Vías Metabólicas/fisiología , Metilenotetrahidrofolato Deshidrogenasa (NADP)/metabolismo , Mitocondrias/metabolismo , Enzimas Multifuncionales/metabolismo , Células Madre Neoplásicas/metabolismo , Purinas/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/metabolismo , Carcinogénesis/metabolismo , Carcinogénesis/patología , Línea Celular , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Ácido Fólico/metabolismo , Regulación Neoplásica de la Expresión Génica/fisiología , Células HEK293 , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Mitocondrias/patología , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Ribonucleótidos/metabolismo , beta Catenina/metabolismoRESUMEN
Amyloid-ß (Aß), a primary component of amyloid plaques, has been widely associated with the pathogenesis of Alzheimer's disease. The Ca2+-binding protein regucalcin (RGN) plays multiple roles in maintaining cell functions by regulating intracellular calcium homeostasis, various signaling pathways, and gene expression systems. Here, we investigated the functional role of RGN against Aß-induced cytotoxicity in neuronally differentiated PC12 cells. Overexpression of RGN reduced Aß-induced apoptosis by reducing mitochondrial dysfunction and caspase activation. It also attenuated Aß-induced reactive oxygen species production and oxidative damage and decreased Aß-induced nitric oxide (NO) overproduction, upregulation of inducible NO synthase by nuclear factor-κB, and nitrosative damage. Interestingly, the genetic disruption of RGN increased the susceptibility of neuronally differentiated PC12 cells to Aß toxicity. Thus, RGN possesses antioxidant activity against Aß-induced oxidative and nitrosative stress and may play protective roles against Aß-induced neurotoxicity in Alzheimer's disease.
RESUMEN
Low-grade sustained inflammation links obesity to insulin resistance and nonalcoholic fatty liver disease (NAFLD). However, therapeutic approaches to improve systemic energy balance and chronic inflammation in obesity are limited. Pharmacological activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) alleviates obesity and insulin resistance in mice; however, Nrf2 inducers are not clinically available owing to safety concerns. Thus, we examined whether dietary glucoraphanin, a stable precursor of the Nrf2 inducer sulforaphane, ameliorates systemic energy balance, chronic inflammation, insulin resistance, and NAFLD in high-fat diet (HFD)-fed mice. Glucoraphanin supplementation attenuated weight gain, decreased hepatic steatosis, and improved glucose tolerance and insulin sensitivity in HFD-fed wild-type mice but not in HFD-fed Nrf2 knockout mice. Compared with vehicle-treated controls, glucoraphanin-treated HFD-fed mice had lower plasma lipopolysaccharide levels and decreased relative abundance of the gram-negative bacteria family Desulfovibrionaceae in their gut microbiomes. In HFD-fed mice, glucoraphanin increased energy expenditure and the protein expression of uncoupling protein 1 (Ucp1) in inguinal and epididymal adipose depots. Additionally, in this group, glucoraphanin attenuated hepatic lipogenic gene expression, lipid peroxidation, classically activated M1-like macrophage accumulation, and inflammatory signaling pathways. By promoting fat browning, limiting metabolic endotoxemia-related chronic inflammation, and modulating redox stress, glucoraphanin may mitigate obesity, insulin resistance, and NAFLD.
Asunto(s)
Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Blanco/efectos de los fármacos , Endotoxemia , Glucosinolatos/farmacología , Imidoésteres/farmacología , Resistencia a la Insulina , Hígado/efectos de los fármacos , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/metabolismo , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Desulfovibrio , Dieta Alta en Grasa , Metabolismo Energético/efectos de los fármacos , Microbioma Gastrointestinal/efectos de los fármacos , Inflamación , Peroxidación de Lípido/efectos de los fármacos , Lipopolisacáridos/sangre , Hígado/metabolismo , Macrófagos/efectos de los fármacos , Ratones , Ratones Noqueados , Factor 2 Relacionado con NF-E2/genética , Oximas , Sulfóxidos , Proteína Desacopladora 1/efectos de los fármacos , Proteína Desacopladora 1/metabolismoRESUMEN
We established an in vitro cell culture system to determine novel activities of the retinoblastoma (Rb) protein during tumor progression. Rb depletion in p53-null mouse-derived soft tissue sarcoma cells induced a spherogenic phenotype. Cells retrieved from Rb-depleted spheres exhibited slower proliferation and less efficient BrdU incorporation, however, much higher spherogenic activity and aggressive behavior. We discovered six miRNAs, including mmu-miR-18a, -25, -29b, -140, -337, and -1839, whose expression levels correlated tightly with the Rb status and spherogenic activity. Among these, mmu-miR-140 appeared to be positively controlled by Rb and to antagonize the effect of Rb depletion on spherogenesis and tumorigenesis. Furthermore, among genes potentially targeted by mmu-miR-140, Il-6 was upregulated by Rb depletion and downregulated by mmu-mir-140 overexpression. Altogether, we demonstrate the possibility that mmu-mir-140 mediates the Rb function to downregulate Il-6 by targeting its 3'-untranslated region. Finally, we detected the same relationship among RB, hsa-miR-140 and IL-6 in a human breast cancer cell line MCF-7. Because IL-6 is a critical modulator of malignant features of cancer cells and the RB pathway is impaired in the majority of cancers, hsa-miR-140 might be a promising therapeutic tool that disrupts linkage between tumor suppressor inactivation and pro-inflammatory cytokine response.