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1.
Immunity ; 56(1): 143-161.e11, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36630913

RESUMO

Although T cells can exert potent anti-tumor immunity, a subset of T helper (Th) cells producing interleukin-22 (IL-22) in breast and lung tumors is linked to dismal patient outcome. Here, we examined the mechanisms whereby these T cells contribute to disease. In murine models of lung and breast cancer, constitutional and T cell-specific deletion of Il22 reduced metastases without affecting primary tumor growth. Deletion of the IL-22 receptor on cancer cells decreases metastasis to a degree similar to that seen in IL-22-deficient mice. IL-22 induced high expression of CD155, which bound to the activating receptor CD226 on NK cells. Excessive activation led to decreased amounts of CD226 and functionally impaired NK cells, which elevated the metastatic burden. IL-22 signaling was also associated with CD155 expression in human datasets and with poor patient outcomes. Taken together, our findings reveal an immunosuppressive circuit activated by T cell-derived IL-22 that promotes lung metastasis.


Assuntos
Interleucinas , Neoplasias , Receptores Virais , Linfócitos T Auxiliares-Indutores , Animais , Humanos , Camundongos , Antígenos de Diferenciação de Linfócitos T/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Células Matadoras Naturais/metabolismo , Neoplasias/metabolismo , Ligação Proteica , Linfócitos T Auxiliares-Indutores/metabolismo , Interleucina 22
3.
Nature ; 546(7660): 676-680, 2017 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-28658220

RESUMO

Cutaneous melanoma is a type of cancer with an inherent potential for lymph node colonization, which is generally preceded by neolymphangiogenesis. However, sentinel lymph node removal does not necessarily extend the overall survival of patients with melanoma. Moreover, lymphatic vessels collapse and become dysfunctional as melanomas progress. Therefore, it is unclear whether (and how) lymphangiogenesis contributes to visceral metastasis. Soluble and vesicle-associated proteins secreted by tumours and/or their stroma have been proposed to condition pre-metastatic sites in patients with melanoma. Still, the identities and prognostic value of lymphangiogenic mediators remain unclear. Moreover, our understanding of lymphangiogenesis (in melanomas and other tumour types) is limited by the paucity of mouse models for live imaging of distal pre-metastatic niches. Injectable lymphatic tracers have been developed, but their limited diffusion precludes whole-body imaging at visceral sites. Vascular endothelial growth factor receptor 3 (VEGFR3) is an attractive 'lymphoreporter' because its expression is strongly downregulated in normal adult lymphatic endothelial cells, but is activated in pathological situations such as inflammation and cancer. Here, we exploit this inducibility of VEGFR3 to engineer mouse melanoma models for whole-body imaging of metastasis generated by human cells, clinical biopsies or endogenously deregulated oncogenic pathways. This strategy revealed early induction of distal pre-metastatic niches uncoupled from lymphangiogenesis at primary lesions. Analyses of the melanoma secretome and validation in clinical specimens showed that the heparin-binding factor midkine is a systemic inducer of neo-lymphangiogenesis that defines patient prognosis. This role of midkine was linked to a paracrine activation of the mTOR pathway in lymphatic endothelial cells. These data support the use of VEGFR3 reporter mice as a 'MetAlert' discovery platform for drivers and inhibitors of metastasis.


Assuntos
Citocinas/metabolismo , Vasos Linfáticos/metabolismo , Metástase Neoplásica/diagnóstico por imagem , Metástase Neoplásica/patologia , Imagem Corporal Total/métodos , Animais , Modelos Animais de Doenças , Progressão da Doença , Células Endoteliais/metabolismo , Feminino , Genes Reporter , Humanos , Linfangiogênese , Vasos Linfáticos/patologia , Masculino , Melanoma/diagnóstico por imagem , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Midkina , Comunicação Parácrina , Prognóstico , Recidiva , Reprodutibilidade dos Testes , Serina-Treonina Quinases TOR/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/análise , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
4.
BMC Cancer ; 14: 965, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25515240

RESUMO

BACKGROUND: DEK is a transcription factor involved in stabilization of heterochromatin and cruciform structures. It plays an important role in development and progression of different types of cancer. This study aims to analyze the role of DEK in metastatic colorectal cancer. METHODS: Baseline DEK expression was firstly quantified in 9 colorectal cell lines and normal mucosa by WB. SiRNA-mediated DEK inhibition was carried out for transient DEK silencing in DLD1 and SW620 to dissect its role in colorectal cancer aggressiveness. Irinotecan response assays were performed with SN38 over 24 hours and apoptosis was quantified by flow cytometry. Ex-vivo assay was carried out with 3 fresh tumour tissues taken from surgical resection and treated with SN38 for 24 hours. DEK expression was determined by immunohistochemistry in 67 formalin-fixed paraffin-embedded tumour samples from metastatic colorectal cancer patients treated with irinotecan-based therapy as first-line treatment. RESULTS: The DEK oncogene is overexpressed in all colorectal cancer cell lines. Knock-down of DEK on DLD1 and SW620 cell lines decreased cell migration and increased irinotecan-induced apoptosis. In addition, low DEK expression level predicted irinotecan-based chemotherapy response in metastatic colorectal cancer patients with KRAS wild-type. CONCLUSIONS: These data suggest DEK overexpression as a crucial event for the emergence of an aggressive phenotype in colorectal cancer and its potential role as biomarker for irinotecan response in those patients with KRAS wild-type status.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Biomarcadores Tumorais/fisiologia , Camptotecina/análogos & derivados , Proteínas Cromossômicas não Histona/fisiologia , Neoplasias Colorretais/tratamento farmacológico , Proteínas Oncogênicas/fisiologia , Adulto , Idoso , Apoptose , Biomarcadores Tumorais/análise , Camptotecina/uso terapêutico , Linhagem Celular Tumoral , Movimento Celular , Sobrevivência Celular , Proteínas Cromossômicas não Histona/análise , Neoplasias Colorretais/química , Neoplasias Colorretais/patologia , Regulação para Baixo , Feminino , Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Irinotecano , Masculino , Pessoa de Meia-Idade , Proteínas Oncogênicas/análise , Fenótipo , Proteínas de Ligação a Poli-ADP-Ribose , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Proteínas ras/genética
5.
Nat Cell Biol ; 8(10): 1053-63, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16964246

RESUMO

Dysfunction of the endoplasmic reticulum (ER) has been reported in a variety of human pathologies, including cancer. However, the contribution of the ER to the early stages of normal cell transformation is largely unknown. Using primary human melanocytes and biopsies of human naevi (moles), we show that the extent of ER stress induced by cellular oncogenes may define the mechanism of activation of premature senescence. Specifically, we found that oncogenic forms of HRAS (HRAS(G12V)) but not its downstream target BRAF (BRAF(V600E)), engaged a rapid cell-cycle arrest that was associated with massive vacuolization and expansion of the ER. However, neither p53, p16(INK4a) nor classical senescence markers--such as foci of heterochromatin or DNA damage--were able to account for the specific response of melanocytes to HRAS(G12V). Instead, HRAS(G12V)-driven senescence was mediated by the ER-associated unfolded protein response (UPR). The impact of HRAS on the UPR was selective, as it was poorly induced by activated NRAS (more frequently mutated in melanoma than HRAS). These results argue against premature senescence as a converging mechanism of response to activating oncogenes and support a direct role of the ER as a gatekeeper of tumour control.


Assuntos
Retículo Endoplasmático/metabolismo , Genes ras/genética , Melanoma/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Ciclo Celular , Proliferação de Células , Senescência Celular , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Dano ao DNA , Fibroblastos/metabolismo , Heterocromatina/genética , Heterocromatina/metabolismo , Humanos , Lactente , Melanócitos/patologia , Melanoma/metabolismo , Melanoma/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Transdução de Sinais
6.
Nat Commun ; 13(1): 2760, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35589749

RESUMO

Autophagy has vasculoprotective roles, but whether and how it regulates lymphatic endothelial cells (LEC) homeostasis and lymphangiogenesis is unknown. Here, we show that genetic deficiency of autophagy in LEC impairs responses to VEGF-C and injury-driven corneal lymphangiogenesis. Autophagy loss in LEC compromises the expression of main effectors of LEC identity, like VEGFR3, affects mitochondrial dynamics and causes an accumulation of lipid droplets (LDs) in vitro and in vivo. When lipophagy is impaired, mitochondrial ATP production, fatty acid oxidation, acetyl-CoA/CoA ratio and expression of lymphangiogenic PROX1 target genes are dwindled. Enforcing mitochondria fusion by silencing dynamin-related-protein 1 (DRP1) in autophagy-deficient LEC fails to restore LDs turnover and lymphatic gene expression, whereas supplementing the fatty acid precursor acetate rescues VEGFR3 levels and signaling, and lymphangiogenesis in LEC-Atg5-/- mice. Our findings reveal that lipophagy in LEC by supporting FAO, preserves a mitochondrial-PROX1 gene expression circuit that safeguards LEC responsiveness to lymphangiogenic mediators and lymphangiogenesis.


Assuntos
Linfangiogênese , Vasos Linfáticos , Animais , Autofagia/genética , Células Endoteliais/metabolismo , Ácidos Graxos/metabolismo , Gotículas Lipídicas/metabolismo , Linfangiogênese/genética , Vasos Linfáticos/metabolismo , Camundongos , Mitocôndrias , Fatores de Transcrição/metabolismo
7.
Nature ; 436(7051): 720-4, 2005 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-16079850

RESUMO

Most normal mammalian cells have a finite lifespan, thought to constitute a protective mechanism against unlimited proliferation. This phenomenon, called senescence, is driven by telomere attrition, which triggers the induction of tumour suppressors including p16(INK4a) (ref. 5). In cultured cells, senescence can be elicited prematurely by oncogenes; however, whether such oncogene-induced senescence represents a physiological process has long been debated. Human naevi (moles) are benign tumours of melanocytes that frequently harbour oncogenic mutations (predominantly V600E, where valine is substituted for glutamic acid) in BRAF, a protein kinase and downstream effector of Ras. Nonetheless, naevi typically remain in a growth-arrested state for decades and only rarely progress into malignancy (melanoma). This raises the question of whether naevi undergo BRAF(V600E)-induced senescence. Here we show that sustained BRAF(V600E) expression in human melanocytes induces cell cycle arrest, which is accompanied by the induction of both p16(INK4a) and senescence-associated acidic beta-galactosidase (SA-beta-Gal) activity, a commonly used senescence marker. Validating these results in vivo, congenital naevi are invariably positive for SA-beta-Gal, demonstrating the presence of this classical senescence-associated marker in a largely growth-arrested, neoplastic human lesion. In growth-arrested melanocytes, both in vitro and in situ, we observed a marked mosaic induction of p16(INK4a), suggesting that factors other than p16(INK4a) contribute to protection against BRAF(V600E)-driven proliferation. Naevi do not appear to suffer from telomere attrition, arguing in favour of an active oncogene-driven senescence process, rather than a loss of replicative potential. Thus, both in vitro and in vivo, BRAF(V600E)-expressing melanocytes display classical hallmarks of senescence, suggesting that oncogene-induced senescence represents a genuine protective physiological process.


Assuntos
Ciclo Celular , Senescência Celular , Nevo/metabolismo , Nevo/patologia , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Linhagem Celular , Proliferação de Células , Inibidor p16 de Quinase Dependente de Ciclina/deficiência , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Fibroblastos , Humanos , Hibridização in Situ Fluorescente , Lactente , Melanócitos/patologia , Nevo/congênito , Nevo/genética , Telômero/genética , Telômero/metabolismo , beta-Galactosidase/metabolismo
8.
Adv Drug Deliv Rev ; 175: 113833, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34147531

RESUMO

Imaging of the lymphatic vasculature has gained great attention in various fields, not only because lymphatic vessels act as a key draining system in the body, but also for their implication in autoimmune diseases, organ transplant, inflammation and cancer. Thus, neolymphangiogenesis, or the generation of new lymphatics, is typically an early event in the development of multiple tumor types, particularly in aggressive ones such as malignant melanoma. Still, the understanding of how lymphatic endothelial cells get activated at distal (pre)metastatic niches and their impact on therapy is still unclear. Addressing these questions is of particular interest in the case of immune modulators, because endothelial cells may favor or halt inflammatory processes depending on the cellular context. Therefore, there is great interest in visualizing the lymphatic vasculature in vivo. Here, we review imaging tools and mouse models used to analyze the lymphatic vasculature during tumor progression. We also discuss therapeutic approaches based on nanomedicines to target the lymphatic system and the potential use of extracellular vesicles to track and target sentinel lymph nodes. Finally, we summarize main pre-clinical models developed to visualize the lymphatic vasculature in vivo, discussing their applications with a particular focus in metastatic melanoma.


Assuntos
Vesículas Extracelulares/metabolismo , Sistema Linfático/diagnóstico por imagem , Sistemas de Liberação de Fármacos por Nanopartículas , Animais , Vesículas Extracelulares/patologia , Humanos , Linfonodos/diagnóstico por imagem , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Sistema Linfático/efeitos dos fármacos , Sistema Linfático/patologia , Vasos Linfáticos/diagnóstico por imagem , Vasos Linfáticos/efeitos dos fármacos , Vasos Linfáticos/patologia , Linfonodo Sentinela/diagnóstico por imagem , Linfonodo Sentinela/patologia
9.
EMBO Mol Med ; 13(12): e12924, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34762341

RESUMO

Long-range communication between tumor cells and the lymphatic vasculature defines competency for metastasis in different cancer types, particularly in melanoma. Nevertheless, the discovery of selective blockers of lymphovascular niches has been compromised by the paucity of experimental systems for whole-body analyses of tumor progression. Here, we exploit immunocompetent and immunodeficient mouse models for live imaging of Vegfr3-driven neolymphangiogenesis, as a versatile platform for drug screening in vivo. Spatiotemporal analyses of autochthonous melanomas and patient-derived xenografts identified double-stranded RNA mimics (dsRNA nanoplexes) as potent inhibitors of neolymphangiogenesis, metastasis, and post-surgical disease relapse. Mechanistically, dsRNA nanoplexes were found to exert a rapid dual action in tumor cells and in their associated lymphatic vasculature, involving the transcriptional repression of the lymphatic drivers Midkine and Vegfr3, respectively. This suppressive function was mediated by a cell-autonomous type I interferon signaling and was not shared by FDA-approved antimelanoma treatments. These results reveal an alternative strategy for targeting the tumor cell-lymphatic crosstalk and underscore the power of Vegfr3-lymphoreporters for pharmacological testing in otherwise aggressive cancers.


Assuntos
Melanoma , RNA de Cadeia Dupla , Animais , Humanos , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos , Camundongos Nus , Transdução de Sinais
10.
Cancer Cell ; 39(5): 610-631, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33545064

RESUMO

There is a lack of appropriate melanoma models that can be used to evaluate the efficacy of novel therapeutic modalities. Here, we discuss the current state of the art of melanoma models including genetically engineered mouse, patient-derived xenograft, zebrafish, and ex vivo and in vitro models. We also identify five major challenges that can be addressed using such models, including metastasis and tumor dormancy, drug resistance, the melanoma immune response, and the impact of aging and environmental exposures on melanoma progression and drug resistance. Additionally, we discuss the opportunity for building models for rare subtypes of melanomas, which represent an unmet critical need. Finally, we identify key recommendations for melanoma models that may improve accuracy of preclinical testing and predict efficacy in clinical trials, to help usher in the next generation of melanoma therapies.


Assuntos
Modelos Animais de Doenças , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Microambiente Tumoral/imunologia , Animais , Humanos , Imunidade/imunologia , Imunoterapia/métodos , Melanoma/patologia , Neoplasias Cutâneas/patologia
11.
Clin Cancer Res ; 27(10): 2678-2697, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33414132

RESUMO

Five years ago, the Melanoma Research Foundation (MRF) conducted an assessment of the challenges and opportunities facing the melanoma research community and patients with melanoma. Since then, remarkable progress has been made on both the basic and clinical research fronts. However, the incidence, recurrence, and death rates for melanoma remain unacceptably high and significant challenges remain. Hence, the MRF Scientific Advisory Council and Breakthrough Consortium, a group that includes clinicians and scientists, reconvened to facilitate intensive discussions on thematic areas essential to melanoma researchers and patients alike, prevention, detection, diagnosis, metastatic dormancy and progression, response and resistance to targeted and immune-based therapy, and the clinical consequences of COVID-19 for patients with melanoma and providers. These extensive discussions helped to crystalize our understanding of the challenges and opportunities facing the broader melanoma community today. In this report, we discuss the progress made since the last MRF assessment, comment on what remains to be overcome, and offer recommendations for the best path forward.


Assuntos
COVID-19/prevenção & controle , Oncologia/métodos , Melanoma/terapia , Guias de Prática Clínica como Assunto , SARS-CoV-2/isolamento & purificação , Neoplasias Cutâneas/terapia , Pesquisa Biomédica/métodos , Pesquisa Biomédica/tendências , COVID-19/epidemiologia , COVID-19/virologia , Humanos , Oncologia/organização & administração , Oncologia/tendências , Melanoma/diagnóstico , SARS-CoV-2/fisiologia , Neoplasias Cutâneas/diagnóstico
12.
Proc Natl Acad Sci U S A ; 104(49): 19488-93, 2007 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-18042711

RESUMO

The proteasome controls a plethora of survival factors in all mammalian cells analyzed to date. Therefore, it is puzzling that proteasome inhibitors such as bortezomib can display a preferential toxicity toward malignant cells. In fact, proteasome inhibitors have the salient feature of promoting a dramatic induction of the proapoptotic protein NOXA in a tumor cell-restricted manner. However, the molecular determinants that control this specific regulation of NOXA are unknown. Here, we show that the induction of NOXA by bortezomib is directly dependent on the oncogene c-MYC. This requirement for c-MYC was found in a variety of tumor cell types, in marked contrast with dispensable roles of p53, HIF-1alpha, and E2F-1 (classical proteasomal targets that can regulate NOXA mRNA under stress). Conserved MYC-binding sites identified at the NOXA promoter were validated by ChIP and reporter assays. Down-regulation of the endogenous levels of c-MYC abrogated the induction of NOXA in proteasome-defective tumor cells. Conversely, forced expression of c-MYC enabled normal cells to accumulate NOXA and subsequently activate cell death programs in response to proteasome blockage. c-MYC is itself a proteasomal target whose levels or function are invariably up-regulated during tumor progression. Our data provide an unexpected function of c-MYC in the control of the apoptotic machinery, and reveal a long sought-after oncogenic event conferring sensitivity to proteasome inhibition.


Assuntos
Antineoplásicos/farmacologia , Ácidos Borônicos/farmacologia , Melanoma/enzimologia , Inibidores de Proteases/farmacologia , Inibidores de Proteassoma , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Pirazinas/farmacologia , Neoplasias Cutâneas/enzimologia , Apoptose/genética , Sítios de Ligação , Bortezomib , Desenho de Fármacos , Fator de Transcrição E2F1/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Interferência de RNA , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ativação Transcricional , Proteína Supressora de Tumor p53/metabolismo
13.
Cancer Cell ; 38(4): 446-448, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-32916127

RESUMO

Lymph nodes are typically the first clinically detectable site of metastasis in melanoma, but the mechanisms that determine this preference are not well understood. An article in Nature reports that the unique composition of lymph may protect melanoma cells from ferroptosis-a form of iron-dependent cell death, thereby increasing metastatic efficiency.


Assuntos
Ferroptose , Melanoma , Humanos , Linfonodos , Metástase Linfática , Melanoma/genética
14.
Nat Med ; 26(12): 1865-1877, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33077955

RESUMO

An open question in aggressive cancers such as melanoma is how malignant cells can shift the immune system to pro-tumorigenic functions. Here we identify midkine (MDK) as a melanoma-secreted driver of an inflamed, but immune evasive, microenvironment that defines poor patient prognosis and resistance to immune checkpoint blockade. Mechanistically, MDK was found to control the transcriptome of melanoma cells, allowing for coordinated activation of nuclear factor-κB and downregulation of interferon-associated pathways. The resulting MDK-modulated secretome educated macrophages towards tolerant phenotypes that promoted CD8+ T cell dysfunction. In contrast, genetic targeting of MDK sensitized melanoma cells to anti-PD-1/anti-PD-L1 treatment. Emphasizing the translational relevance of these findings, the expression profile of MDK-depleted tumors was enriched in key indicators of a good response to immune checkpoint blockers in independent patient cohorts. Together, these data reveal that MDK acts as an internal modulator of autocrine and paracrine signals that maintain immune suppression in aggressive melanomas.


Assuntos
Carcinogênese/efeitos dos fármacos , Melanoma Experimental/terapia , Midkina/genética , Microambiente Tumoral/genética , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Linfócitos T CD8-Positivos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Terapia Genética , Humanos , Melanoma Experimental/genética , Melanoma Experimental/patologia , Camundongos , Midkina/farmacologia , NF-kappa B/genética , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Transcriptoma/genética
16.
Cancer Res ; 67(20): 9685-93, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17942898

RESUMO

The current understanding of the interaction between the endothelium and cancer cells is fundamentally based on the concept that endothelial cells are responsive to differentiation and survival signals originating from the tumor cells. Whereas the effect of tumor cell-secreted factors on angiogenesis is well established, little is known about the effect of factors secreted by endothelial cells on tumor cell gene expression and tumor progression. Here, we show that bcl-2 gene expression is significantly higher in the tumor-associated endothelial cells of patients with head and neck squamous cell carcinomas (HNSCC) as compared with endothelial cells from the normal oral mucosa. Bcl-2 induces vascular endothelial growth factor (VEGF) expression in neovascular endothelial cells through a signal transducer and activator of transcription 3 (STAT3)-mediated pathway. Endothelial cell-derived VEGF signals through VEGFR1 and induces expression of Bcl-2 and the proangiogenic chemokines CXCL1 and CXCL8 in HNSCC cells. Notably, inhibition of Bcl-2 expression in neovascular endothelial cells with RNA interference down-regulates expression of Bcl-2, CXCL8, and CXCL1 in HNSCC cells, and is sufficient to inhibit growth and decrease the microvessel density of xenografted HNSCC in immunodeficient mice. Together, these results show that Bcl-2 is the orchestrator of a cross-talk between neovascular endothelial cells and tumor cells, which has a direct effect on tumor growth. This work identifies a new function for Bcl-2 in cancer biology that is beyond its classic role in cell survival.


Assuntos
Carcinoma de Células Escamosas/patologia , Células Endoteliais/patologia , Neoplasias de Cabeça e Pescoço/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/genética , Processos de Crescimento Celular/fisiologia , Quimiocina CXCL1/biossíntese , Células Endoteliais/metabolismo , Genes bcl-2 , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/genética , Humanos , Interleucina-8/biossíntese , Camundongos , Camundongos SCID , Mucosa Bucal/irrigação sanguínea , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fator de Transcrição STAT3/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/biossíntese , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo
17.
Cancer Res ; 67(1): 209-17, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17210701

RESUMO

Unlike other tumors, melanomas harbor wild-type (WT) p53 but exhibit impaired p53-dependent apoptosis. The mechanisms for the impaired p53 activation are poorly understood but may be linked to the high expression of the p53 suppressor Mdm2, which is found in >50% of melanoma lesions. Here, we describe an organometallic glycogen synthase kinase 3beta (GSK3beta) inhibitor (DW1/2) as a potent activator of p53 and inducer of cell death in otherwise highly chemoresistant melanoma cells. Using RNA interference and pharmacologic approaches, we show that p53 is required for the cytotoxic effects of this organometallic inhibitor. The DW1/2 compound was barely able to induce cell death in melanoma cells with p53 mutations, further confirming the requirement for p53-WT in the cytotoxic effects of the GSK3beta inhibition. Mechanistic analysis of the p53-dependent cell death indicated an apoptotic mechanism involving depolarization of mitochondrial membrane potential, caspase cleavage, and elevated NOXA expression. The effect of p53 was not simply due to passive up-regulation of protein expression as adenoviral-mediated overexpression of p53 was not able to induce cell death. Treatment of melanoma cells with DW1/2 was instead found to decrease levels of Mdm2 and Mdm4. The importance of Mdm2 down-regulation in DW1/2-induced apoptosis was confirmed by treating the p53-WT cells with the p53/Mdm2 antagonist Nutlin-3. Taken together, our data provide a new strategy for the pharmacologic activation of p53 in melanoma, which may be a viable approach for overcoming apoptotic resistance in melanoma and offer new hope for rational melanoma therapy.


Assuntos
Apoptose/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Melanoma/tratamento farmacológico , Compostos Organometálicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Apoptose/fisiologia , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Melanoma/metabolismo , Melanoma/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Rutênio/química , Rutênio/farmacologia , Proteína Supressora de Tumor p53/biossíntese , Regulação para Cima
18.
Oncogene ; 38(19): 3585-3597, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30664687

RESUMO

Although antioxidants promote melanoma metastasis, the role of reactive oxygen species (ROS) in other stages of melanoma progression is controversial. Moreover, genes regulating ROS have not been functionally characterized throughout the entire tumor progression in mouse models of cancer. To address this question, we crossed mice-bearing knock-out of Klf9, an ubiquitous transcriptional regulator of oxidative stress, with two conditional melanocytic mouse models: BrafCA mice, where BrafV600E causes premalignant melanocytic hyperplasia, and BrafCA/Pten-/- mice, where BrafV600E and loss of Pten induce primary melanomas and metastases. Klf9 deficiency inhibited premalignant melanocytic hyperplasia in BrafCA mice but did not affect formation and growth of BrafCA/Pten-/- primary melanomas. It also, as expected, promoted BrafCA/Pten-/- metastasis. Treatment with antioxidant N-acetyl cysteine phenocopied loss of Klf9 including suppression of melanocytic hyperplasia. We were interested in a different role of Klf9 in regulation of cell proliferation in BrafCA and BrafCA/Pten-/- melanocytic cells. Mechanistically, we demonstrated that BRAFV600E signaling transcriptionally upregulated KLF9 and that KLF9-dependent ROS were required for full-scale activation of ERK1/2 and induction of cell proliferation by BRAFV600E. PTEN depletion in BRAFV600E-melanocytes did not further activate ERK1/2 and cell proliferation, but rendered these phenotypes insensitive to KLF9 and ROS. Our data identified an essential role of KLF9-dependent ROS in BRAFV600E signaling in premalignant melanocytes, offered an explanation to variable role of ROS in premalignant and transformed melanocytic cells and suggested a novel mechanism for suppression of premalignant growth by topical antioxidants.


Assuntos
Fatores de Transcrição Kruppel-Like/metabolismo , Melanoma/patologia , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Cutâneas/patologia , Acetilcisteína/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Humanos , Fatores de Transcrição Kruppel-Like/genética , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/patologia , Melanoma/genética , Melanoma/metabolismo , Melanoma Experimental/induzido quimicamente , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Neoplasias Cutâneas/metabolismo
19.
Cancer Cell ; 35(1): 46-63.e10, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30581152

RESUMO

Modulators of mRNA stability are not well understood in melanoma, an aggressive tumor with complex changes in the transcriptome. Here we report the ability of p62/SQSTM1 to extend mRNA half-life of a spectrum of pro-metastatic factors. These include FERMT2 and other transcripts with no previous links to melanoma. Transcriptomic, proteomic, and interactomic analyses, combined with validation in clinical biopsies and mouse models, identified a selected set of RNA-binding proteins (RBPs) recruited by p62, with IGF2BP1 as a key partner. This p62-RBP interaction distinguishes melanoma from other tumors where p62 controls autophagy or oxidative stress. The relevance of these data is emphasized by follow-up analyses of patient prognosis revealing p62 and FERMT2 as adverse determinants of disease-free survival.


Assuntos
Melanoma/metabolismo , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , RNA Mensageiro/química , Proteínas de Ligação a RNA/metabolismo , Proteína Sequestossoma-1/metabolismo , Animais , Linhagem Celular Tumoral , Progressão da Doença , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/genética , Proteínas de Membrana/química , Camundongos , Proteínas de Neoplasias/química , Transplante de Neoplasias , Mapas de Interação de Proteínas , Proteômica/métodos , Estabilidade de RNA , Análise Serial de Tecidos
20.
Cancer Res ; 66(23): 11348-59, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17145881

RESUMO

The RAS/BRAF/MEK/ERK mitogen-activated protein kinase (MAPK) pathway is emerging as a key modulator of melanoma initiation and progression. However, a variety of clinical studies indicate that inhibiting the MAPK pathway is insufficient per se to effectively kill melanoma cells. Here, we report on a genetic and pharmacologic approach to identify survival factors responsible for the resistance of melanoma cells to MEK/ERK antagonists. In addition, we describe a new tumor cell-selective means to bypass this resistance in vitro and in vivo. By generating a panel of isogenic cell lines with specific defects in the apoptotic machinery, we found that the ability of melanoma cells to survive in the absence of functional MEK relies on an ERK-independent expression of the antiapoptotic factor Mcl-1 (and to a lesser extent, Bcl-x(L) and Bcl-2). Using computer-based modeling, we developed a novel Bcl-2 homology domain 3 (BH3) mimetic. This compound, named TW-37, is the first rationally designed small molecule with high affinity for Mcl-1, Bcl-x(L), and Bcl-2. Mechanistic analyses of the mode of action of TW-37 showed a synergistic tumor cell killing in the presence of MEK inhibitors. Importantly, TW-37 unveiled an unexpected role of the MAPK pathway in the control of reactive oxygen species (ROS). This function was critical to prevent the activation of proapoptotic functions of p53 in melanoma cells, but surprisingly, it was dispensable for normal melanocytes. Our results suggest that this MAPK-dependent ROS/p53 feedback loop is a point of vulnerability of melanoma cells that can be exploited for rational drug design.


Assuntos
Benzamidas/farmacologia , Melanoma/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sulfonas/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Benzamidas/química , Butadienos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/patologia , Melanoma/prevenção & controle , Camundongos , Camundongos Nus , Microscopia de Fluorescência , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Estrutura Molecular , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Interferência de RNA , Sulfonas/química , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
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