RESUMO
There is growing evidence that ion channels are critically involved in cancer cell invasiveness and metastasis. However, the molecular mechanisms of ion signaling promoting cancer behavior are poorly understood and the complexity of the underlying remodeling during metastasis remains to be explored. Here, using a variety of in vitro and in vivo techniques, we show that metastatic prostate cancer cells acquire a specific Na+ /Ca2+ signature required for persistent invasion. We identify the Na+ leak channel, NALCN, which is overexpressed in metastatic prostate cancer, as a major initiator and regulator of Ca2+ oscillations required for invadopodia formation. Indeed, NALCN-mediated Na+ influx into cancer cells maintains intracellular Ca2+ oscillations via a specific chain of ion transport proteins including plasmalemmal and mitochondrial Na+ /Ca2+ exchangers, SERCA and store-operated channels. This signaling cascade promotes activity of the NACLN-colocalized proto-oncogene Src kinase, actin remodeling and secretion of proteolytic enzymes, thus increasing cancer cell invasive potential and metastatic lesions in vivo. Overall, our findings provide new insights into an ion signaling pathway specific for metastatic cells where NALCN acts as persistent invasion controller.
Assuntos
Neoplasias da Próstata , Sódio , Masculino , Humanos , Sódio/metabolismo , Canais Iônicos/metabolismo , Transporte de Íons , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismoRESUMO
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with high mortality due to early metastatic dissemination and high chemoresistance. All these factors are favored by its extracellular matrix (ECM)-rich microenvironment, which is also highly hypoxic and acidic. Gemcitabine (GEM) is still the first-line therapy in PDAC. However, it is quickly deaminated to its inactive metabolite. Several GEM prodrugs have emerged to improve its cytotoxicity. Here, we analyzed how the acidic/hypoxic tumor microenvironment (TME) affects the response of PDAC cell death and invadopodia-mediated ECM proteolysis to both GEM and its C18 prodrug. METHODS: For this, two PDAC cell lines, PANC-1 and Mia PaCa-2 were adapted to pHe 6.6 or not for 1 month, grown as 3D organotypic cultures and exposed to either GEM or C18 in the presence and absence of acidosis and the hypoxia inducer, deferoxamine. RESULTS: We found that C18 has higher cytotoxic and anti-invadopodia activity than GEM in all culture conditions and especially in acid and hypoxic environments. CONCLUSIONS: We propose C18 as a more effective approach to conventional GEM in developing new therapeutic strategies overcoming PDAC chemoresistance.
Assuntos
Desoxicitidina , Gencitabina , Neoplasias Pancreáticas , Microambiente Tumoral , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Humanos , Microambiente Tumoral/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Linhagem Celular Tumoral , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/metabolismo , Podossomos/metabolismo , Podossomos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Pró-Fármacos/farmacologiaRESUMO
Endothelial cells (ECs) are highly plastic, capable of differentiating into various cell types. Endothelial-to-mesenchymal transition (EndMT) is crucial during embryonic development and contributes substantially to vascular dysfunction in many cardiovascular diseases (CVDs). While targeting EndMT holds therapeutic promise, understanding its mechanisms and modulating its pathways remain challenging. Using single-cell RNA sequencing on three in vitro EndMT models, we identified conserved gene signatures. We validated original regulators in vitro and in vivo during embryonic heart development and peripheral artery disease. EndMT induction led to global expression changes in all EC subtypes rather than in mesenchymal clusters. We identified mitochondrial calcium uptake as a key driver of EndMT; inhibiting mitochondrial calcium uniporter (MCU) prevented EndMT in vitro, and conditional Mcu deletion in ECs blocked mesenchymal activation in a hind limb ischemia model. Tissues from patients with critical limb ischemia with EndMT features exhibited significantly elevated endothelial MCU. These findings highlight MCU as a regulator of EndMT and a potential therapeutic target.
Assuntos
Sinalização do Cálcio , Células Endoteliais , Transição Epitelial-Mesenquimal , Mitocôndrias , RNA-Seq , Análise de Célula Única , Animais , Humanos , Mitocôndrias/metabolismo , RNA-Seq/métodos , Camundongos , Células Endoteliais/metabolismo , Transição Epitelial-Mesenquimal/genética , Canais de Cálcio/metabolismo , Canais de Cálcio/genética , Isquemia/metabolismo , Isquemia/patologia , Cálcio/metabolismo , Análise da Expressão Gênica de Célula ÚnicaRESUMO
The antifungal activity and in vitro toxicity toward animal cells of two inhibitors of oxidosqualene cyclase, squalene bis-diethylamine (SBD) and squalene bis-diethylmethylammonium iodide (SBDI) were studied. Minimum inhibitory concentration (MIC) against dermatophytes and other fungi involved in cutaneous and systemic infections (12 isolates from seven species) were determined by the broth microdilution method based on the reference documents M38-A and M27-A2 of Clinical and Laboratory Standards Institute (CLSI). Both compounds exerted fungistatic activities, although with different action. SBDI was the more active compound and displayed low MIC values (in the 3.12-12.5 µg ml(-1) range) against Microsporum canis, Trichophyton mentagrophytes and one isolate of Scopulariopsis brevicaulis, while SBD showed MIC values against these species in the 3.12-25 µg ml(-1) range. Toxicity was tested on Madin-Darby canine kidney (MDCK) epithelial cells and human microvascular endothelial cells (HMEC). SBDI proved the less toxic compound: it inhibited M. canis, T. mentagrophytes and S. brevicaulis at concentrations below those found toxic for MDCK cells. HMEC were the more sensitive cells.
Assuntos
Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Transferases Intramoleculares/antagonistas & inibidores , Esqualeno/análogos & derivados , Esqualeno/farmacologia , Animais , Antifúngicos/química , Antifúngicos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cães , Humanos , Testes de Sensibilidade Microbiana , Esqualeno/toxicidadeRESUMO
Endothelial cell adhesion and migration are critical steps of the angiogenic process, whose dysfunction is associated with tumor growth and metastasis. The TRPM8 channel has recently been proposed to play a protective role in prostate cancer by impairing cell motility. However, the mechanisms by which it could influence vascular behavior are unknown. Here, we reveal a novel non-channel function for TRPM8 that unexpectedly acts as a Rap1 GTPase inhibitor, thereby inhibiting endothelial cell motility, independently of pore function. TRPM8 retains Rap1 intracellularly through direct protein-protein interaction, thus preventing its cytoplasm-plasma membrane trafficking. In turn, this mechanism impairs the activation of a major inside-out signaling pathway that triggers the conformational activation of integrin and, consequently, cell adhesion, migration, in vitro endothelial tube formation, and spheroid sprouting. Our results bring to light a novel, pore-independent molecular mechanism by which endogenous TRPM8 expression inhibits Rap1 GTPase and thus plays a critical role in the behavior of vascular endothelial cells by inhibiting migration.
Assuntos
Movimento Celular , Células Endoteliais/enzimologia , Neovascularização Fisiológica , Canais de Cátion TRPM/metabolismo , Proteínas rap1 de Ligação ao GTP/metabolismo , Adesão Celular , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/enzimologia , Humanos , Integrina beta1/metabolismo , Microscopia Confocal , Microscopia de Fluorescência , Microscopia de Vídeo , Modelos Cardiovasculares , Ligação Proteica , Transporte Proteico , Interferência de RNA , Transdução de Sinais , Canais de Cátion TRPM/genética , Fatores de Tempo , Transfecção , Proteínas rap1 de Ligação ao GTP/genéticaRESUMO
Hydrogen sulfide (H(2)S) is a gasotransmitter that plays several roles in various tissues, including the cardiovascular system. Because it has been recently proposed to act as a mediator of angiogenesis progression, here we investigate the effects of H(2)S in a well-established model of tumor angiogenesis: endothelial cells obtained from human breast carcinoma (B-TECs). Ca(2+) imaging and patch-clamp experiments reveal that acute perfusion with NaHS, a widely employed H(2)S donor, activates cytosolic calcium (Ca(c)) increase, as well as potassium and nonselective cationic currents, in B-TECs. Stimulation with NaHS in the same concentration range (1 nM-200 µM) evoked Ca(c) signals also in "normal" human microvascular endothelial cells (HMVECs), but the amplitude was significantly lower. Moreover, although NaHS failed to promote either migration or proliferation on HMVECs, B-TEC migration was enhanced at low-micromolar NaHS concentrations (1-10 µM). Remarkably H(2)S mediates tumor proangiogenic signaling triggered by vascular endothelial growth factor (VEGF). B-TECs pretreated with dl-propargylglycine (5mM, 30 min), an inhibitor of the H(2)S-producing enzyme cystathionine γ-lyase, showed drastically reduced migration and Ca(c) signals induced by VEGF (20 ng/ml). We conclude that H(2)S plays a role in proangiogenic signaling of tumor-derived but not normal human ECs. Furthermore the ability of this gasotransmitter to interfere with B-TEC responsiveness to VEGF suggests that it could be an interesting target for antiangiogenic strategies in tumor treatment.