RESUMO
Glioma cells recruit and exploit microglia (the resident immune cells of the brain) for their proliferation and invasion ability. The underlying molecular mechanism used by glioma cells to transform microglia into a tumor-supporting phenotype has remained elusive. We found that glioma-induced microglia conversion was coupled to a reduction in the basal activity of microglial caspase-3 and increased S-nitrosylation of mitochondria-associated caspase-3 through inhibition of thioredoxin-2 activity, and that inhibition of caspase-3 regulated microglial tumor-supporting function. Furthermore, we identified the activity of nitric oxide synthase 2 (NOS2, also known as iNOS) originating from the glioma cells as a driving stimulus in the control of microglial caspase-3 activity. Repression of glioma NOS2 expression in vivo led to a reduction in both microglia recruitment and tumor expansion, whereas depletion of microglial caspase-3 gene promoted tumor growth. Our results provide evidence that inhibition of the denitrosylation of S-nitrosylated procaspase-3 mediated by the redox protein Trx2 is a part of the microglial pro-tumoral activation pathway initiated by glioma cancer cells.
Assuntos
Caspase 3/metabolismo , Glioma/metabolismo , Glioma/patologia , Microglia/metabolismo , Fenótipo , Animais , Linhagem Celular Tumoral , Movimento Celular , Modelos Animais de Doenças , Ativação Enzimática , Técnicas de Silenciamento de Genes , Glioma/imunologia , Xenoenxertos , Humanos , Masculino , Camundongos , Microglia/imunologia , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Tiorredoxinas/metabolismo , Carga TumoralRESUMO
BACKGROUND: Immune cells can regulate disease progression and response to treatment in multiple tumor types, but their activities in human soft tissue sarcoma are poorly characterized. METHODS: Marker-defined immune cell subsets were characterized from a tumor microenvironmental perspective in two independent cohorts of human soft tissue sarcoma by multiplex IHC, quantitative PCR and/or bioinformatics. RESULTS: B cell profiling revealed a prognostic role for CD20 protein (cohort 1, 33 patients) and MS4A1 gene expression (cohort 2, 265 patients). Multiplex IHC and gene correlation analysis supported a role in antigen presentation, immune cell differentiation and T cell activation. The prognostic role of MS4A1 expressing B cells was only observed in an IL10low, PTGS2low or CD163low tumor microenvironment according to the transcriptomic data. IL10 levels consistently correlated with the M2-like macrophage marker CD163, which also defined the majority of macrophages. A polarization of these cells toward a pro-tumoral phenotype was further supported by lack of correlation between CD163 and M1 markers like NOS2, as well as by low abundance of CD80 positive cells in tissue. CONCLUSIONS: Analysis of CD20/MS4A1 expression in soft tissue sarcoma merits further attention as a promising candidate prognostic tool for survival, but not in patients with a pronounced immunosuppressive tumor microenvironment. Macrophages are ubiquitous and polarized toward a protumoral phenotype. This provides a rationale for further studies on B cell function and immunotherapy targeting M2-polarized macrophages.
Assuntos
Antígenos CD20/imunologia , Linfócitos B/imunologia , Macrófagos/imunologia , Sarcoma/imunologia , Neoplasias de Tecidos Moles/imunologia , Transcriptoma/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD20/genética , Antígenos CD20/metabolismo , Linfócitos B/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/imunologia , Biomarcadores Tumorais/metabolismo , Estudos de Coortes , Feminino , Humanos , Estimativa de Kaplan-Meier , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Sarcoma/genética , Sarcoma/metabolismo , Neoplasias de Tecidos Moles/genética , Neoplasias de Tecidos Moles/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia , Adulto JovemRESUMO
BACKGROUND: Expression of the chemokine CXCL14 has previously been shown to be elevated in the tumour stroma of, for example, prostate and breast cancer. Cancer-associated fibroblast-derived CXCL14 enhances tumour growth in mouse models of prostate and breast cancer. However, the prognostic significance of compartment-specific expression of CXCL14 has not been studied. METHODS: CXCL14 mRNA expression was analysed in a breast cancer tissue microarray (TMA) of formalin-fixed, paraffin-embedded tumours by the RNAscope 2.0 Assay. Epithelial and stromal expression was analysed separately and correlated with clinicopathological characteristics and survival. RESULTS: CXCL14 was variably and independently expressed in malignant and stromal cells of breast cancer. Total and stromal expression of CXCL14 did not associate with clinicopathological parameters. Epithelial CXCL14 expression was significantly associated with oestrogen receptor α (ERα)-positive tumours and lower proliferation status. Total CXCL14 expression correlated significantly with shorter breast cancer-specific and recurrence-free survival. High stromal, but not epithelial, CXCL14 expression was significantly associated with shorter survival in univariable and multivariable analyses. Moreover, the correlation between stromal CXCL14 expression and survival was more prominent in ER negative, triple negative and basal-like breast cancers. CONCLUSIONS: The identification of prognostic significance of stromal CXCL14 in breast cancer demonstrates novel clinical relevance of a stroma-derived secreted factor and illustrates the importance of tumour compartment-specific analyses. On the basis of the prognostic signals from difficult-to-treat subgroups, CXCL14 should also be considered as a candidate drug target.
Assuntos
Neoplasias da Mama/patologia , Quimiocinas CXC/genética , Células Estromais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Células Estromais/metabolismo , Análise de SobrevidaRESUMO
The inhibitory reversible oxidation of protein tyrosine phosphatases (PTPs) is an important regulatory mechanism in growth factor signaling. Studies on PTP oxidation have focused on pathways that increase or decrease reactive oxygen species levels and thereby affect PTP oxidation. The processes involved in reactivation of oxidized PTPs remain largely unknown. Here the role of the thioredoxin (Trx) system in reactivation of oxidized PTPs was analyzed using a combination of in vitro and cell-based assays. Cells lacking the major Trx reductase TrxR1 (Txnrd1(-/-)) displayed increased oxidation of PTP1B, whereas SHP2 oxidation was unchanged. Furthermore, in vivo-oxidized PTP1B was reduced by exogenously added Trx system components, whereas SHP2 oxidation remained unchanged. Trx1 reduced oxidized PTP1B in vitro but failed to reactivate oxidized SHP2. Interestingly, the alternative TrxR1 substrate TRP14 also reactivated oxidized PTP1B, but not SHP2. Txnrd1-depleted cells displayed increased phosphorylation of PDGF-ß receptor, and an enhanced mitogenic response, after PDGF-BB stimulation. The TrxR inhibitor auranofin also increased PDGF-ß receptor phosphorylation. This effect was not observed in cells specifically lacking PTP1B. Together these results demonstrate that the Trx system, including both Trx1 and TRP14, impacts differentially on the oxidation of individual PTPs, with a preference of PTP1B over SHP2 activation. The studies demonstrate a previously unrecognized pathway for selective redox-regulated control of receptor tyrosine kinase signaling.
Assuntos
Ativação Enzimática/fisiologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais/fisiologia , Tiorredoxinas/farmacologia , Animais , Ativação Enzimática/efeitos dos fármacos , Fibroblastos , Técnicas de Inativação de Genes , Violeta Genciana , Camundongos , Oxirredução , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxina Redutase 1/deficiênciaRESUMO
In this study, we describe a novel gene expression signature of platelet-derived growth factor (PDGF)-activated fibroblasts, which is able to identify breast cancers with a PDGF-stimulated fibroblast stroma and displays an independent and strong prognostic significance. Global gene expression was compared between PDGF-stimulated human fibroblasts and cultured resting fibroblasts. The most differentially expressed genes were reduced to a gene expression signature of 113 genes. The biological significance and prognostic capacity of this signature were investigated using four independent clinical breast cancer data sets. Concomitant high expression of PDGFß receptor and its cognate ligands is associated with a high PDGF signature score. This supports the notion that the signature detects tumors with PDGF-activated stroma. Subsequent analyses indicated significant associations between high PDGF signature score and clinical characteristics, including human epidermal growth factor receptor 2 positivity, estrogen receptor negativity, high tumor grade, and large tumor size. A high PDGF signature score is associated with shorter survival in univariate analysis. Furthermore, the high PDGF signature score acts as a significant marker of poor prognosis in multivariate survival analyses, including classic prognostic markers, Ki-67 status, a proliferation gene signature, or other recently described stroma-derived gene expression signatures.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Células Cultivadas , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/fisiologia , Genes Neoplásicos , Humanos , Estimativa de Kaplan-Meier , Ligantes , Pessoa de Meia-Idade , Gradação de Tumores , Proteínas de Neoplasias/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas c-sis/farmacologia , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais/fisiologia , Células Estromais/metabolismoRESUMO
BACKGROUND: Ras is a membrane-associated small G-protein that funnels growth and differentiation signals into downstream signal transduction pathways by cycling between an inactive, GDP-bound and an active, GTP-bound state. Aberrant Ras activity as a result of oncogenic mutations causes de novo cell transformation and promotes tumor growth and progression. RESULTS: Here, we describe a novel strategy to block deregulated Ras activity by means of oligomerized cognate protein modules derived from the Ras-binding domain of c-Raf (RBD), which we named MSOR for multivalent scavengers of oncogenic Ras. The introduction of well-characterized mutations into RBD was used to adjust the affinity and hence the blocking potency of MSOR towards activated Ras. MSOR inhibited several oncogenic Ras-stimulated processes including downstream activation of Erk1/2, induction of matrix-degrading enzymes, cell motility and invasiveness in a graded fashion depending on the oligomerization grade and the nature of the individual RBD-modules. The amenability to accurate experimental regulation was further improved by engineering an inducible MSOR-expression system to render the reversal of oncogenic Ras effects controllable. CONCLUSION: MSOR represent a new tool for the experimental and possibly therapeutic selective blockade of oncogenic Ras signals.
Assuntos
Proteínas Proto-Oncogênicas c-raf/metabolismo , Transdução de Sinais , Proteínas ras/metabolismo , Animais , Células COS , Chlorocebus aethiops , Camundongos , Células NIH 3T3 , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-raf/química , Proteínas Proto-Oncogênicas c-raf/genética , Proteínas ras/químicaRESUMO
BACKGROUND: The multikinase inhibitor sorafenib inhibits angiogenesis and tumor cell proliferation. Sorafenib targets signaling pathways involved in liver regeneration. Previous works on regenerating mouse liver show differing results. We asked to which degree different lengths of sorafenib treatment would influence liver regeneration after hepatic resection in rats. METHODS: Fischer-344 rats received intragastric injections of sorafenib (5-15 mg/kg/d), underwent a two-thirds partial hepatectomy (PH), and were sacrificed at different time points thereafter. Sorafenib treatment was stopped 0, 3, or 14 d after PH. Serum levels of aminotransferases and labeling indices of S-phase nuclei (bromodeoxyuridine and MIB-5) were analyzed, body and liver weights measured, and levels of phospho-ERK determined by Western blot. RESULTS: Sorafenib increased aminotransferases and the number of S-phase nuclei at baseline, but decreased liver weights and levels of phospho-ERK 24 h after PH. The number of S-phase nuclei and mitotic indices decreased 48 h after PH and increased 7 d after PH in animals on sorafenib treatment. Relative liver weights were restored 5 d after PH in control rats, at 7 d in animals receiving sorafenib prior to surgery, at 10 d in rats where sorafenib was stopped 3 d after surgery, and after 14 d in rats on continuous treatment. CONCLUSIONS: In this rat model, the regenerating liver adapted to the proliferation-inhibitory effect of sorafenib during continuous treatment. Sorafenib given after hepatic resection did not completely inhibit liver regeneration, but it prolonged the regenerative phase in proportion to the length of treatment.
Assuntos
Hepatectomia/métodos , Regeneração Hepática/efeitos dos fármacos , Fígado/cirurgia , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Regeneração Hepática/fisiologia , Masculino , Modelos Animais , Niacinamida/farmacologia , Ratos , Ratos Endogâmicos F344 , Transdução de Sinais/efeitos dos fármacos , Sorafenibe , Fatores de Tempo , Transaminases/sangueRESUMO
This study explored the role of secreted fibroblast-derived factors in prostate cancer growth. Analyses of matched normal and tumor tissue revealed up-regulation of CXCL14 in cancer-associated fibroblasts of a majority of prostate cancer. Fibroblasts over-expressing CXCL14 promoted the growth of prostate cancer xenografts, and increased tumor angiogenesis and macrophage infiltration. Mechanistic studies demonstrated that autocrine CXCL14-stimulation of fibroblasts stimulate migration and ERK-dependent proliferation of fibroblasts. CXCL14-stimulation of monocyte migration was also demonstrated. Furthermore, CXCL14-producing fibroblasts, but not recombinant CXCL14, enhanced in vitro proliferation and migration of prostate cancer cells and in vivo angiogenesis. These studies thus identify CXCL14 as a novel autocrine stimulator of fibroblast growth and migration, with multi-modal tumor-stimulatory activities. In more general terms, our findings suggest autocrine stimulation of fibroblasts as a previously unrecognized mechanism for chemokine-mediated stimulation of tumor growth, and suggest a novel mechanism whereby cancer-associated fibroblasts achieve their pro-tumorigenic phenotype.
Assuntos
Comunicação Autócrina , Quimiocinas CXC/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Quimiocinas CXC/genética , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Fibroblastos , Humanos , Macrófagos , Masculino , Camundongos , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neoplasias da Próstata/genética , Células Estromais/citologia , Células Estromais/metabolismo , Regulação para Cima , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: Tissue-specific markers are useful for identification of tumour type in advanced cancers of unknown origin. This study investigated the expression of glutamate decarboxylase 1 (GAD1) in prostate and control tissue compared with the established prostate-specific markers prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA). MATERIAL AND METHODS: A tissue microarray was constructed of 36 prostate adenocarcinomas, eight benign prostate samples and benign and malignant control tissues from urinary bladder, lung and rectum. Immunohistochemistry for GAD1, PSA and PSMA was performed. The products of staining intensity and extent were analysed. The GAD1 antibody was validated by Western blot. Real-time polymerase chain reaction (RT-PCR) was performed on malignant and benign samples from each tissue type. RESULTS: GAD1 and PSA immunostains were significantly stronger in malignant and benign prostatic tissue than in controls. PSMA was stronger in prostate cancer than in urothelial and rectal cancer but had a lower specificity than GAD1 and PSA. GAD1 expression decreased with increasing Gleason score. RT-PCR confirmed the presence of mRNA for GAD1, PSA and PSMA in prostate samples. CONCLUSION: GAD1 is expressed in benign and malignant prostatic tissue and may serve as a highly prostate-specific tissue biomarker.
Assuntos
Biomarcadores Tumorais/metabolismo , Glutamato Descarboxilase/metabolismo , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Idoso , Antígenos de Superfície/metabolismo , Biomarcadores/metabolismo , Biópsia , Estudos de Casos e Controles , Glutamato Carboxipeptidase II/metabolismo , Humanos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Próstata/patologia , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/patologia , Reto/metabolismo , Reto/patologia , Sensibilidade e Especificidade , Bexiga Urinária/metabolismo , Bexiga Urinária/patologiaRESUMO
Chemokines regulate directed cell migration, proliferation and survival and are key components in cancer biology. They exert their functions by interacting with seven-transmembrane domain receptors that signal through G proteins (GPCRs). A subgroup of four chemokine receptors known as the atypical chemokine receptors (ACKRs) has emerged as essential regulators of the chemokine functions. ACKRs play diverse and complex roles in tumor biology from tumor initiation to metastasis, including cancer cell proliferation, adherence to endothelium, epithelial-mesenchymal transition (EMT), extravasation from blood vessels, tumor-associated angiogenesis or protection from immunological responses. This chapter gives an overview on the established and emerging roles that the atypical chemokine receptors ACKR1, ACKR2, ACKR3 and ACKR4 play in the different phases of cancer development and dissemination, their clinical relevance, as well as on the hurdles to overcome in ACKRs targeting as cancer therapy.
Assuntos
Antineoplásicos/uso terapêutico , Quimiocinas/metabolismo , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Receptores de Quimiocinas/antagonistas & inibidores , Animais , Proliferação de Células , Humanos , Metástase Neoplásica , Neoplasias/metabolismo , Neoplasias/patologia , Receptores de Quimiocinas/metabolismo , Transdução de SinaisRESUMO
Cancer-associated fibroblasts (CAFs) promote tumor growth and progression, and increase drug resistance through several mechanisms. We have investigated the effect of CAFs on the p53 response to doxorubicin in prostate cancer cells. We show that CAFs produce interleukin-6 (IL-6), and that IL-6 attenuates p53 induction and upregulation of the pro-apoptotic p53 target Bax upon treatment with doxorubicin. This is associated with increased levels of MDM2 mRNA, Mdm2 protein bound to p53, and ubiquitinated p53. IL-6 also inhibited doxorubicin-induced cell death. Inhibition of JAK or STAT3 alleviated this effect, indicating that IL-6 attenuates p53 via the JAK/STAT signaling pathway. These results suggest that CAF-derived IL-6 plays an important role in protecting cancer cells from chemotherapy and that inhibition of IL-6 could have significant therapeutic value.
RESUMO
PURPOSE: Fibroblasts expressing the orphan chemokine CXCL14 have been previously shown to associate with poor breast cancer prognosis and promote cancer growth. This study explores the mechanism underlying the poor survival associations of stromal CXCL14. EXPERIMENTAL DESIGN: Tumor cell epithelial-to-mesenchymal transition (EMT), invasion, and metastasis were studied in in vitro and in vivo models together with fibroblasts overexpressing CXCL14. An approach for CXCL14 receptor identification included loss-of-function studies followed by molecular and functional endpoints. The clinical relevance was further explored in publicly available gene expression datasets. RESULTS: CXCL14 fibroblasts stimulated breast cancer EMT, migration, and invasion in breast cancer cells and in a xenograft model. Furthermore, tumor cells primed by CXCL14 fibroblasts displayed enhanced lung colonization after tail-vein injection. By loss-of function experiments, the atypical G-protein-coupled receptor ACKR2 was identified to mediate CXCL14-stimulated responses. Downregulation of ACKR2, or CXCL14-induced NOS1, attenuated the pro-EMT and migratory capacity. CXCL14/ACKR2 expression correlated with EMT and survival in gene expression datasets. CONCLUSIONS: Collectively, the findings imply an autocrine fibroblast CXCL14/ACKR2 pathway as a clinically relevant stimulator of EMT, tumor cell invasion, and metastasis. The study also identifies ACKR2 as a novel mediator for CXCL14 function and thereby defines a pathway with drug target potential.See related commentary by Zhang et al., p. 3476.
Assuntos
Neoplasias da Mama/genética , Transição Epitelial-Mesenquimal , Linhagem Celular Tumoral , Quimiocinas CXC/genética , Fibroblastos , Regulação Neoplásica da Expressão Gênica , HumanosRESUMO
Cancer cells adapt to their inherently increased oxidative stress through activation of the glutathione (GSH) and thioredoxin (TXN) systems. Inhibition of both of these systems effectively kills cancer cells, but such broad inhibition of antioxidant activity also kills normal cells, which is highly unwanted in a clinical setting. We therefore evaluated targeting of the TXN pathway alone and, more specifically, selective inhibition of the cytosolic selenocysteine-containing enzyme TXN reductase 1 (TXNRD1). TXNRD1 inhibitors were discovered in a large screening effort and displayed increased specificity compared to pan-TXNRD inhibitors, such as auranofin, that also inhibit the mitochondrial enzyme TXNRD2 and additional targets. For our lead compounds, TXNRD1 inhibition correlated with cancer cell cytotoxicity, and inhibitor-triggered conversion of TXNRD1 from an antioxidant to a pro-oxidant enzyme correlated with corresponding increases in cellular production of H2O2 In mice, the most specific TXNRD1 inhibitor, here described as TXNRD1 inhibitor 1 (TRi-1), impaired growth and viability of human tumor xenografts and syngeneic mouse tumors while having little mitochondrial toxicity and being better tolerated than auranofin. These results display the therapeutic anticancer potential of irreversibly targeting cytosolic TXNRD1 using small molecules and present potent and selective TXNRD1 inhibitors. Given the pronounced up-regulation of TXNRD1 in several metastatic malignancies, it seems worthwhile to further explore the potential benefit of specific irreversible TXNRD1 inhibitors for anticancer therapy.
Assuntos
Citosol/enzimologia , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Tiorredoxina Redutase 1/antagonistas & inibidores , Animais , Antioxidantes/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores Enzimáticos/análise , Inibidores Enzimáticos/farmacologia , Ensaios de Triagem em Larga Escala , Peróxido de Hidrogênio/metabolismo , Masculino , Camundongos SCID , Oxirredução , Relação Estrutura-Atividade , Tiorredoxina Redutase 1/química , Tiorredoxina Redutase 1/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Drug resistance is a major problem in cancer therapy. A growing body of evidence demonstrates that the tumor microenvironment, including cancer-associated fibroblasts (CAFs), can modulate drug sensitivity in tumor cells. We examined the effect of primary human CAFs on p53 induction and cell viability in prostate cancer cells on treatment with chemotherapeutic drugs. Co-culture with prostate CAFs or CAF-conditioned medium attenuated DNA damage and the p53 response to chemotherapeutic drugs and enhanced prostate cancer cell survival. CAF-conditioned medium inhibited the accumulation of doxorubicin, but not taxol, in prostate cancer cells in a manner that was associated with increased cancer cell glutathione levels. A low molecular weight fraction (<3 kDa) of CAF-conditioned medium had the same effect. CAF-conditioned medium also inhibited induction of reactive oxygen species (ROS) in both doxorubicin- and taxol-treated cancer cells. Our findings suggest that CAFs can enhance drug resistance in cancer cells by inhibiting drug accumulation and counteracting drug-induced oxidative stress. This protective mechanism may represent a novel therapeutic target in cancer.
Assuntos
Antineoplásicos/farmacologia , Fibroblastos Associados a Câncer/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Glutationa/agonistas , Neoplasias da Próstata/genética , Proteína Supressora de Tumor p53/genética , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Meios de Cultivo Condicionados/farmacologia , Dano ao DNA , Doxorrubicina/antagonistas & inibidores , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Glutationa/metabolismo , Humanos , Masculino , Paclitaxel/antagonistas & inibidores , Paclitaxel/farmacologia , Cultura Primária de Células , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Microambiente Tumoral/efeitos dos fármacos , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismoRESUMO
Tumor- or cancer-associated fibroblasts (CAFs) are one of the most abundant stromal cell types in different carcinomas and comprise a heterogeneous cell population. Classically, CAFs are assigned with pro-tumorigenic effects stimulating tumor growth and progression. More recent studies demonstrated also tumor-inhibitory effects of CAFs suggesting that tumor-residing fibroblasts exhibit a similar degree of plasticity as other stromal cell types. Reciprocal interactions with the tumor milieu and different sources of origin are emerging as two important factors underlying CAF heterogeneity. This review highlights recent advances in our understanding of CAF biology and proposes to expand the term of cellular "polarization," previously introduced to describe different activation states of various immune cells, onto CAFs to reflect their phenotypic diversity.
RESUMO
Tumor-associated macrophages (TAMs) are a prominent cell type of the tumor stroma and stimulate malignant cell growth, survival and metastasis. The present manuscript demonstrates that prostate cancer cell-derived factors induce a pro-tumoral TAM-like phenotype characterized by increased proliferation and increased expression of pro-angiogenic, immunosuppressive and pro-metastatic factors. These effects were abrogated by all trans-retinoic acid (ATRA), a clinically available molecule with known immune-modulating properties. Furthermore, ATRA inhibited the cancer cell-stimulated proliferation of the pro-tumoral macrophages and restored their cytotoxic capacity towards prostate cancer cells. These findings suggest the use of ATRA as an immunomodulating agent to block the activity of prostate cancer TAMs.
Assuntos
Macrófagos/efeitos dos fármacos , Neovascularização Patológica/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Tretinoína/farmacologia , Carcinogênese/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Citotoxicidade Imunológica/efeitos dos fármacos , Humanos , Terapia de Imunossupressão , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Metástase Neoplásica , Fosforilação/efeitos dos fármacos , Neoplasias da Próstata/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Quinase Induzida por NF-kappaBRESUMO
Growth factor receptors induce a transient increase in reactive oxygen species (ROS) levels upon receptor binding to promote signaling through oxidation of protein tyrosine phosphatases (PTPs). Most studies have focused on NADPH oxidases as the dominant source of ROS to induce PTP oxidation. A potential additional regulator of growth factor-induced PTP oxidation is p66Shc, which stimulates mitochondrial ROS production. This study explores the contribution of p66Shc-induced ROS to PTP oxidation and growth factor receptor-induced signaling and migration through analyses of p66Shc-KO fibroblasts and cells with siRNA-mediated p66Shc downregulation. Analyses of PDGFßR phosphorylation in two independent cell systems demonstrated a decrease in PDGFßR phosphorylation after p66Shc deletion or downregulation, which occurred in a partially site-selective and antioxidant-sensitive manner. Deletion of p66Shc also reduced PDGF-induced activation of downstream signaling of Erk, Akt, PLCγ-1, and FAK. Importantly, reduced levels of p66Shc led to decreased oxidation of DEP1, PTP1B, and SHP2 after PDGF stimulation. The cell biological relevance of these findings was indicated by demonstration of a significantly reduced migratory response in PDGF-stimulated p66Shc-KO fibroblasts, consistent with reduced PDGFßR-Y1021 and PLCγ-1 phosphorylation. Downregulation of p66Shc also reduced EGFR phosphorylation and signaling, indicating that the positive role of p66Shc in receptor tyrosine kinase signaling is potentially general. Moreover, downregulation of the mitochondrial hydrogen peroxide scavenger peroxiredoxin 3 increased PDGFßR phosphorylation, showing that mitochondrial ROS in general promote PDGFßR signaling. This study thus identifies a previously unrecognized role for p66Shc in the regulation of PTP oxidation controlling growth factor-induced signaling and migration. In more general terms, the study indicates a regulatory role for mitochondrial-derived ROS in the control of PTP oxidation influencing growth factor signaling.
Assuntos
Proteínas Tirosina Fosfatases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Adaptadoras da Sinalização Shc/metabolismo , Animais , Movimento Celular/genética , Fibroblastos/metabolismo , Radicais Livres/metabolismo , Peróxido de Hidrogênio/metabolismo , Camundongos , Mitocôndrias/metabolismo , Células NIH 3T3 , Oxirredução , Proteínas Tirosina Fosfatases/genética , Transdução de Sinais/genética , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de SrcRESUMO
Cancer-associated fibroblasts (CAF) stimulate tumor growth and metastasis. Signals supporting CAF function are thus emerging as candidate therapeutic targets in the tumor microenvironment. The chemokine CXCL14 is a potent inducer of CAF protumorigenic functions. This study is aimed at learning how the protumoral functions of CXCL14-expressing CAF are maintained. We found that the nitric oxide synthase NOS1 is upregulated in CXCL14-expressing CAF and in fibroblasts stimulated with CXCL14. Induction of Nos1 was associated with oxidative stress and occurred together with activation of NRF2 and HIF1α signaling in CXCL14-expressing CAF. Genetic or pharmacologic inhibition of NOS1 reduced the growth of CXCL14-expressing fibroblasts along with their ability to promote tumor formation following coinjection with prostate or breast cancer cells. Tumor analysis revealed reduced macrophage infiltration, with NOS1 downregulation in CXCL14-expressing CAF and lymphangiogenesis as a novel component of CXCL14-promoted tumor growth. Collectively, our findings defined key components of a signaling network that maintains the protumoral functions of CXCL14-stimulated CAF, and they identified NOS1 as intervention target for CAF-directed cancer therapy.
Assuntos
Quimiocinas CXC/metabolismo , Fibroblastos/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Quimiocinas CXC/biossíntese , Quimiocinas CXC/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , Camundongos SCID , Óxido Nítrico/genética , Óxido Nítrico Sintase Tipo I/genética , Estresse Oxidativo/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/genética , Regulação para CimaRESUMO
The tumor stroma is vital to tumor development, progression, and metastasis. Cancer-associated fibroblasts (CAF) are among the abundant cell types in the tumor stroma, but the range of their contributions to cancer pathogenicity has yet to be fully understood. Here, we report a critical role for upregulation of the TGFß/BMP family member GDF15 (MIC-1) in tumor stroma. GDF15 was found upregulated in situ and in primary cultures of CAF from prostate cancer. Ectopic expression of GDF15 in fibroblasts produced prominent paracrine effects on prostate cancer cell migration, invasion, and tumor growth. Notably, GDF15-expressing fibroblasts exerted systemic in vivo effects on the outgrowth of distant and otherwise indolent prostate cancer cells. Our findings identify tumor stromal cells as a novel source of GDF15 in human prostate cancer and illustrate a systemic mechanism of cancer progression driven by the tumor microenvironment. Further, they provide a functional basis to understand GDF15 as a biomarker of poor prognosis and a candidate therapeutic target in prostate cancer.
Assuntos
Transformação Celular Neoplásica/patologia , Fibroblastos/patologia , Fator 15 de Diferenciação de Crescimento/genética , Neoplasias da Próstata/patologia , Células 3T3 , Animais , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica , Fator 15 de Diferenciação de Crescimento/biossíntese , Xenoenxertos/crescimento & desenvolvimento , Humanos , Masculino , Camundongos , Camundongos SCID , Invasividade Neoplásica/patologia , Transplante de Neoplasias , Microambiente Tumoral , Regulação para CimaRESUMO
Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum) and after completed exercise (exercise serum). The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.