RESUMO
BACKGROUND: The incidence of melanoma is increasing worldwide. Since metastatic melanoma is highly aggressive, it is important to decipher all the biological aspects of melanoma cells. In this context, we have previously shown that metastatic FEMX-I melanoma cells release small (< 150 nm) extracellular vesicles (EVs) known as exosomes and ectosomes containing the stem (and cancer stem) cell antigenic marker CD133. EVs play an important role in intercellular communication, which could have a micro-environmental impact on surrounding tissues. RESULTS: We report here a new type of large CD133+ EVs released by FEMX-I cells. Their sizes range from 2 to 6 µm and they contain lipid droplets and mitochondria. Real-time video microscopy revealed that these EVs originate from the lipid droplet-enriched cell extremities that did not completely retract during the cell division process. Once released, they can be taken up by other cells. Silencing CD133 significantly affected the cellular distribution of lipid droplets, with a re-localization around the nuclear compartment. As a result, the formation of large EVs containing lipid droplets was severely compromised. CONCLUSION: Given the biochemical effect of lipid droplets and mitochondria and/or their complexes on cell metabolism, the release and uptake of these new large CD133+ EVs from dividing aggressive melanoma cells can influence both donor and recipient cells, and therefore impact melanoma growth and dissemination.
Assuntos
Vesículas Extracelulares , Melanoma , Humanos , Melanoma/patologia , Gotículas Lipídicas/metabolismo , Gotículas Lipídicas/patologia , Vesículas Extracelulares/metabolismo , Divisão Celular , Mitocôndrias/metabolismoRESUMO
Extracellular vesicles (EVs) appear to play an important role in intercellular communication in various physiological processes and pathological conditions such as cancer. Like enveloped viruses, EVs can transport their contents into the nucleus of recipient cells, and a new intracellular pathway has been described to explain the nuclear shuttling of EV cargoes. It involves a tripartite protein complex consisting of vesicle-associated membrane protein-associated protein A (VAP-A), oxysterol-binding protein (OSBP)-related protein-3 (ORP3) and late endosome-associated Rab7 allowing late endosome entry into the nucleoplasmic reticulum. Rab7 binding to ORP3-VAP-A complex can be blocked by the FDA-approved antifungal drug itraconazole. Here, we design a new series of smaller triazole derivatives, which lack the dioxolane moiety responsible for the antifungal function, acting on the hydrophobic sterol-binding pocket of ORP3 and evaluate their structure-activity relationship through inhibition of VOR interactions and nuclear transfer of EV and HIV-1 cargoes. Our investigation reveals that the most effective compounds that prevent nuclear transfer of EV cargo and productive infection by VSV-G-pseudotyped HIV-1 are those with a side chain between 1 and 4 carbons, linear or branched (methyl) on the triazolone region. These potent chemical drugs could find clinical applications either for nuclear transfer of cancer-derived EVs that impact metastasis or viral infection.
Assuntos
Infecções por HIV , Triazóis , Triazóis/química , Triazóis/farmacologia , Triazóis/síntese química , Humanos , Relação Estrutura-Atividade , Estrutura Molecular , Infecções por HIV/tratamento farmacológico , Infecções por HIV/metabolismo , HIV-1/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Relação Dose-Resposta a Droga , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologiaRESUMO
Proper temporal and spatial activation of stem cells relies on highly coordinated cell signaling. The primary cilium is the sensory organelle that is responsible for transmitting extracellular signals into a cell. Primary cilium size, architecture, and assembly-disassembly dynamics are under rigid cell cycle-dependent control. Using mouse incisor tooth epithelia as a model, we show that ciliary dynamics in stem cells require the proper functions of a cholesterol-binding membrane glycoprotein, Prominin-1 (Prom1/CD133), which controls sequential recruitment of ciliary membrane components, histone deacetylase, and transcription factors. Nuclear translocation of Prom1 and these molecules is particularly evident in transit amplifying cells, the immediate derivatives of stem cells. The absence of Prom1 impairs ciliary dynamics and abolishes the growth stimulation effects of sonic hedgehog (SHH) treatment, resulting in the disruption of stem cell quiescence maintenance and activation. We propose that Prom1 is a key regulator ensuring appropriate response of stem cells to extracellular signals, with important implications for development, regeneration, and diseases.
Assuntos
Antígeno AC133/metabolismo , Cílios/metabolismo , Incisivo/citologia , Antígeno AC133/genética , Animais , Núcleo Celular/metabolismo , Células Cultivadas , Humanos , Incisivo/metabolismo , Camundongos , Modelos Biológicos , Mutagênese Sítio-Dirigida , Transporte Proteico , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/metabolismoRESUMO
BACKGROUND: Multipotent mesenchymal stromal cells (MSCs) are precursors of various cell types. Through soluble factors, direct cell-cell interactions and other intercellular communication mechanisms such as extracellular vesicles and tunneling nanotubes, MSCs support tissue homeostasis. In the bone marrow microenvironment, they promote hematopoiesis. The interaction between MSCs and cancer cells enhances the cancer and metastatic potential. Here, we have demonstrated that plastic-adherent MSCs isolated from human bone marrow generate migrasomes, a newly discovered organelle playing a role in intercellular communication. RESULTS: Migrasomes are forming a network with retraction fibers behind the migrating MSCs or surrounding them after membrane retraction. The MSC markers, CD44, CD73, CD90, CD105 and CD166 are present on the migrasome network, the latter being specific to migrasomes. Some migrasomes harbor the late endosomal GTPase Rab7 and exosomal marker CD63 indicating the presence of multivesicular bodies. Stromal cell-derived factor 1 (SDF-1) was detected in migrasomes, suggesting that they play a chemoattractant role. Co-cultures with KG-1a leukemic cells or primary CD34+ hematopoietic progenitors revealed that MSC-associated migrasomes attracted them, a process intercepted by the addition of AMD3100, a specific CXCR4 receptor inhibitor, or recombinant SDF-1. An antibody directed against CD166 reduced the association of hematopoietic cells and MSC-associated migrasomes. In contrast to primary CD34+ progenitors, leukemic cells can take up migrasomes. CONCLUSION: Overall, we described a novel mechanism used by MSCs to communicate with cells of hematopoietic origin and further studies are needed to decipher all biological aspects of migrasomes in the healthy and transformed bone marrow microenvironment. Video Abstract.
Assuntos
Fatores Quimiotáticos , Células-Tronco Mesenquimais , Humanos , Fatores Quimiotáticos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Hematopoéticas , Células Cultivadas , Antígenos CD34/metabolismo , Células da Medula Óssea , Diferenciação Celular , Células Estromais/metabolismoRESUMO
Prominin-1 is a cell surface biomarker that allows the identification of stem and cancer stem cells from different organs. It is also expressed in several differentiated epithelial and non-epithelial cells. Irrespective of the cell type, prominin-1 is associated with plasma membrane protrusions. Here, we investigate its impact on the architecture of membrane protrusions using microvilli of Madin-Darby canine kidney cells as the main model. Our high-resolution analysis revealed that upon the overexpression of prominin-1 the number of microvilli and clusters of them increased. Microvilli with branched and/or knob-like morphologies were observed and stimulated by mutations in the ganglioside-binding site of prominin-1. The altered phenotypes were caused by the interaction of prominin-1 with phosphoinositide 3-kinase and Arp2/3 complex. Mutation of tyrosine 828 of prominin-1 impaired its phosphorylation and thereby inhibited the aforementioned interactions abolishing altered microvilli. This suggests that the interplay of prominin-1-ganglioside membrane complexes, phosphoinositide 3-kinase and cytoskeleton components regulates microvillar architecture. Lastly, the expression of prominin-1 and its mutants modified the structure of filopodia emerging from fibroblast-like cells and silencing human prominin-1 in primary hematopoietic stem cells resulted in the loss of uropod-associated microvilli. Altogether, these findings strengthen the role of prominin-1 as an organizer of cellular protrusions.
Assuntos
Antígeno AC133/metabolismo , Microvilosidades/metabolismo , Antígeno AC133/química , Antígeno AC133/genética , Animais , Sítios de Ligação , Células CHO , Células Cultivadas , Cricetinae , Cricetulus , Cães , Gangliosídeos/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos C57BL , Microvilosidades/ultraestrutura , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Ligação ProteicaRESUMO
Prominins (proms) are transmembrane glycoproteins conserved throughout the animal kingdom. They are associated with plasma membrane protrusions, such as primary cilia, as well as extracellular vesicles derived thereof. Primary cilia host numerous signaling pathways affected in diseases known as ciliopathies. Human PROM1 (CD133) is detected in both somatic and cancer stem cells and is also expressed in terminally differentiated epithelial and photoreceptor cells. Genetic mutations in the PROM1 gene result in retinal degeneration by impairing the proper formation of the outer segment of photoreceptors, a modified cilium. Here, we investigated the impact of proms on two distinct examples of ciliogenesis. First, we demonstrate that the overexpression of a dominant-negative mutant variant of human PROM1 (i.e. mutation Y819F/Y828F) significantly decreases ciliary length in Madin-Darby canine kidney cells. These results contrast strongly to the previously observed enhancing effect of WT PROM1 on ciliary length. Mechanistically, the mutation impeded the interaction of PROM1 with ADP-ribosylation factor-like protein 13B, a key regulator of ciliary length. Second, we observed that in vivo knockdown of prom3 in zebrafish alters the number and length of monocilia in the Kupffer's vesicle, resulting in molecular and anatomical defects in the left-right asymmetry. These distinct loss-of-function approaches in two biological systems reveal that prom proteins are critical for the integrity and function of cilia. Our data provide new insights into ciliogenesis and might be of particular interest for investigations of the etiologies of ciliopathies.
Assuntos
Antígeno AC133/metabolismo , Cílios/metabolismo , Peixe-Zebra , Antígeno AC133/química , Antígeno AC133/genética , Animais , Cães , Regulação para Baixo , Regulação da Expressão Gênica no Desenvolvimento , Espaço Intracelular/metabolismo , Células de Kupffer/citologia , Células Madin Darby de Rim Canino , Mutação , Transporte Proteico , TirosinaRESUMO
The intercellular communication mediated by extracellular vesicles (EVs) has gained international interest during the last decade. Interfering with the mechanisms regulating this cellular process might find application particularly in oncology where cancer cell-derived EVs play a role in tumour microenvironment transformation. Although several mechanisms were ascribed to explain the internalization of EVs, little is our knowledge about the fate of their cargos, which are crucial to mediate their function. We recently demonstrated a new intracellular pathway in which a fraction of endocytosed EV-associated proteins is transported into the nucleoplasm of the host cell via a subpopulation of late endosomes penetrating into the nucleoplasmic reticulum. Silencing tetraspanin CD9 both in EVs and recipient cells strongly decreased the endocytosis of EVs and abolished the nuclear transfer of their cargos. Here, we investigated whether monovalent Fab fragments derived from 5H9 anti-CD9 monoclonal antibody (referred hereafter as CD9 Fab) interfered with these cellular processes. To monitor the intracellular transport of proteins, we used fluorescent EVs containing CD9-green fluorescent protein fusion protein and various melanoma cell lines and bone marrow-derived mesenchymal stromal cells as recipient cells. Interestingly, CD9 Fab considerably reduced EV uptake and the nuclear transfer of their proteins in all examined cells. In contrast, the divalent CD9 antibody stimulated both events. By impeding intercellular communication in the tumour microenvironment, CD9 Fab-mediated inhibition of EV uptake, combined with direct targeting of cancerous cells could lead to the development of novel anti-melanoma therapeutic strategies.
Assuntos
Transporte Ativo do Núcleo Celular , Vesículas Extracelulares/efeitos dos fármacos , Fragmentos Fab das Imunoglobulinas/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Melanoma/tratamento farmacológico , Proteínas de Neoplasias/metabolismo , Tetraspanina 29/imunologia , Comunicação Celular , Células Cultivadas , Endocitose/efeitos dos fármacos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patologia , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Melanoma/imunologia , Melanoma/metabolismo , Melanoma/patologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologiaRESUMO
The endocytic pathway plays an instrumental role in recycling internalized molecules back to the plasma membrane or in directing them to lysosomes for degradation. We recently reported a new role of endosomes-the delivery of components from extracellular vesicles (EVs) to the nucleoplasm of recipient cells. Using indirect immunofluorescence, FRET, immunoisolation techniques, and RNAi, we report here a tripartite protein complex (referred to as the VOR complex) that is essential for the nuclear transfer of EV-derived components by orchestrating the specific localization of late endosomes into nucleoplasmic reticulum. We found that the VOR complex contains the endoplasmic reticulum-localized vesicle-associated membrane protein (VAMP)-associated protein A (VAP-A), the cytoplasmic oxysterol-binding protein-related protein 3 (ORP3), and late endosome-associated small GTPase Rab7. The silencing of VAP-A or ORP3 abrogated the association of Rab7-positive late endosomes with nuclear envelope invaginations and, hence, the transport of endocytosed EV-derived components to the nucleoplasm of recipient cells. We conclude that the VOR complex can be targeted to inhibit EV-mediated intercellular communication, which can have therapeutic potential for managing cancer in which the release of EVs is dysregulated.
Assuntos
Proteínas de Transporte/fisiologia , Retículo Endoplasmático/metabolismo , Endossomos/metabolismo , Complexos Multiproteicos/química , Membrana Nuclear/metabolismo , Proteínas de Transporte Vesicular/fisiologia , Comunicação Celular , Células Cultivadas , Endocitose , Proteínas de Ligação a Ácido Graxo , Humanos , Complexos Multiproteicos/fisiologia , Proteínas R-SNARE , Receptores de Esteroides , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7RESUMO
This study originally aimed to investigate whether the overexpression of SOX2 is associated with the poor prognosis of patients with squamous cell carcinoma of the esophagus. However, we unexpectedly found that esophageal squamous cell carcinomas completely lacking SOX2 expression showed distinct pathologic features and highly aggressive clinical courses. The study cohort consisted of 113 consecutive patients with esophageal squamous cell carcinoma who underwent surgical resection without neoadjuvant therapy. Immunostaining on tissue microarrays and whole sections revealed that 8/113 (7%) cases were entirely negative for this transcriptional factor. SOX2-negative cancers were histologically less differentiated (P=0.002) and showed higher pT and pStages (P=0.003 and 0.007, respectively) than SOX2-positive cases. A remarkable finding was widespread lymphatic infiltration distant from the primary invasive focus, which was observed in 4 SOX2-negative cancers (50%), but none of the SOX2-positive cases. All separate dysplastic lesions observed in SOX2-negative cases were also SOX2-negative. The negative expression of SOX2 appeared to be an independent poor prognostic factor (OR=7.05, 95% CI=1.27-39.0). No mutations were identified in the coding or non-coding regions of SOX2. Fluorescent in situ hybridization did not show any copy-number variations in this gene. Since the SOX2 promoter contains an extensive CpG island, SOX2-negative cases underwent methylation-specific PCR, which disclosed promoter hypermethylation in all cases. In conclusion, SOX2-silenced squamous cell carcinomas of the esophagus appear to be a minor, but distinct form of malignancy characterized by extensive lymphatic invasion, a poor prognosis, and potential association with multiple SOX2-negative neoplastic lesions. The hypermethylation of the promoter region is seemingly a critical epigenetic event leading to SOX2 silencing.
Assuntos
Metilação de DNA/genética , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/genética , Regiões Promotoras Genéticas/genética , Fatores de Transcrição SOXB1/genética , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/mortalidade , Carcinoma de Células Escamosas do Esôfago/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática/genética , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos ProporcionaisRESUMO
Diabetes mellitus (DM) is reaching epidemic conditions worldwide and increases the risk for cognition impairment and dementia. Here, we postulated that progenitors in adult neurogenic niches might be particularly vulnerable. Therefore, we evaluated the different components of the mouse subventricular zone (SVZ) during the first week after chemical induction of type 1 and type 2 diabetes-like (T1DM and T2DM) conditions. Surprisingly, only T2DM mice showed SVZ damage. The initial lesions were localized to ependymal cilia, which appeared disorientated and clumped together. In addition, they showed delocalization of the ciliary membrane protein prominin-1. Impairment of neuroprogenitor proliferation, neurogenic marker abnormalities and ectopic migration of neuroblasts were found at a later stage. To our knowledge, our data describe for the first time such an early impact of T2DM on the SVZ. This is consistent with clinical data indicating that brain damage in T2DM patients differs from that in T1DM patients.
Assuntos
Antígeno AC133/metabolismo , Cílios/fisiologia , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Neurogênese/fisiologia , Nicho de Células-Tronco/fisiologia , Antígeno AC133/genética , Animais , Células Cultivadas , Ventrículos Cerebrais , Cílios/patologia , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 2/patologia , Progressão da Doença , Epêndima/patologia , Epêndima/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Distribuição AleatóriaAssuntos
Antígeno AC133/genética , Ascite/genética , Biomarcadores Tumorais/genética , Vesículas Extracelulares/metabolismo , Neoplasias Pancreáticas/genética , Processamento de Proteína Pós-Traducional , Antígeno AC133/metabolismo , Artefatos , Ascite/diagnóstico , Ascite/metabolismo , Ascite/patologia , Biomarcadores Tumorais/metabolismo , Vesículas Extracelulares/patologia , Glicosilação , Humanos , Imuno-Histoquímica/normas , Pâncreas/metabolismo , Pâncreas/patologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosforilação , UbiquitinaçãoRESUMO
Dynamic rearrangements of the F-actin cytoskeleton are a hallmark of tumor metastasis. Thus, proteins that govern F-actin rearrangements are of major interest for understanding metastasis and potential therapies. We hypothesized that the unique F-actin binding and bundling protein SWAP-70 contributes importantly to metastasis. Orthotopic, ectopic, and short-term tail vein injection mouse breast and lung cancer models revealed a strong positive dependence of lung and bone metastasis on SWAP-70. Breast cancer cell growth, migration, adhesion, and invasion assays revealed SWAP-70's key role in these metastasis-related cell features and the requirement for SWAP-70 to bind F-actin. Biophysical experiments showed that tumor cell stiffness and deformability are negatively modulated by SWAP-70. Together, we present a hitherto undescribed, unique F-actin modulator as an important contributor to tumor metastasis.
Assuntos
Actinas , Neoplasias da Mama , Proteínas de Ligação a DNA , Fatores de Troca do Nucleotídeo Guanina , Neoplasias Pulmonares , Proteínas dos Microfilamentos , Antígenos de Histocompatibilidade Menor , Metástase Neoplásica , Animais , Feminino , Humanos , Camundongos , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/genética , Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , Proteínas dos Microfilamentos/metabolismo , Proteínas dos Microfilamentos/genética , Ligação Proteica , Antígenos de Histocompatibilidade Menor/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismoRESUMO
Our knowledge of the first member of the prominin family is growing rapidly as the clinical value of prominin-1 (CD133) increases with its ever-wider use as a stem cell marker in normal and cancer tissues. Although the physiological function of this evolutionally conserved pentaspan membrane glycoprotein remains elusive, several studies have revealed new biological features regarding stem cells, cancer stem cells, and photoreceptors. The wide expression of CD133 in terminally differentiated epithelial cells, long overlooked by many authors, has attracted significant interest through the extensive investigation of human PROMININ-1 as a potential target for cancer therapies in various organs. Biochemically, this cholesterol-binding protein is selectively concentrated in plasma membrane protrusions, where it is associated with cholesterol-driven membrane microdomains. Clinically, mutations in the PROM1 gene are associated with various forms of retinal degeneration, which are mimicked in genetically modified mice carrying either a null allele or mutated form of PROMININ-1. In this introductory chapter, we attempted to review 15 years of prominin-1 study, focusing on its unique protein characteristics across species and the recent developments regarding its cell biology that may shed new light on its intriguing involvement in defining cancer-initiating cells.
Assuntos
Células Epiteliais , Glicoproteínas de Membrana , Animais , Diferenciação Celular , Células Epiteliais/metabolismo , Humanos , Glicoproteínas de Membrana/metabolismo , Microdomínios da Membrana/metabolismo , Células-Tronco Neoplásicas/metabolismoRESUMO
The mechanism of human immunodeficiency virus 1 (HIV-1) nuclear entry, required for productive infection, is not fully understood. Here, we report that in HeLa cells and activated CD4+ T cells infected with HIV-1 pseudotyped with VSV-G and native Env protein, respectively, Rab7+ late endosomes containing endocytosed HIV-1 promote the formation of nuclear envelope invaginations (NEIs) by a molecular mechanism involving the VOR complex, composed of the outer nuclear membrane protein VAP-A, hyperphosphorylated ORP3 and Rab7. Silencing VAP-A or ORP3 and drug-mediated impairment of Rab7 binding to ORP3-VAP-A inhibited the nuclear transfer of the HIV-1 components and productive infection. In HIV-1-resistant quiescent CD4+ T cells, ORP3 was not hyperphosphorylated and neither VOR complex nor NEIs were formed. This new cellular pathway and its molecular players are potential therapeutic targets, perhaps shared by other viruses that require nuclear entry to complete their life cycle.
Assuntos
Infecções por HIV , HIV-1 , Humanos , HIV-1/metabolismo , Células HeLa , Linfócitos T CD4-Positivos/metabolismo , Produtos do Gene env/metabolismo , Proteínas de Membrana/metabolismoRESUMO
Breast cancer is a heterogeneous disease and the mechanistic framework for differential osteotropism among intrinsic breast cancer subtypes is unknown. Hypothesizing that cell morphology could be an integrated readout for the functional state of a cancer cell, we established a catalogue of the migratory, molecular and biophysical traits of MDA-MB-231 breast cancer cells, compared it with two enhanced bone-seeking derivative cell lines and integrated these findings with single cell morphology profiles. Such knowledge could be essential for predicting metastatic capacities in breast cancer. High-resolution microscopy revealed a heterogeneous and specific spectrum of single cell morphologies in bone-seeking cells, which correlated with differential migration and stiffness. While parental MDA-MB-231 cells showed long and dynamic membrane protrusions and were enriched in motile cells with continuous and mesenchymal cell migration, bone-seeking cells appeared with discontinuous mesenchymal or amoeboid-like migration. Although non-responsive to CXCL12, bone-seeking cells responded to epidermal growth factor with a morphotype shift and differential expression of genes controlling cell shape and directional migration. Hence, single cell morphology encodes the molecular, migratory and biophysical architecture of breast cancer cells and is specifically altered among osteotropic phenotypes. Quantitative morpho-profiling could aid in dissecting breast cancer heterogeneity and in refining clinically relevant intrinsic breast cancer subtypes.
RESUMO
Intercellular communication between cancer cells themselves or with healthy cells in the tumor microenvironment and/or pre-metastatic sites plays an important role in cancer progression and metastasis. In addition to ligand-receptor signaling complexes, extracellular vesicles (EVs) are emerging as novel mediators of intercellular communication both in tissue homeostasis and in diseases such as cancer. EV-mediated transfer of molecular activities impacting morphological features and cell motility from highly metastatic SW620 cells to non-metastatic SW480 cells is a good in vitro example to illustrate the increased malignancy of colorectal cancer leading to its transformation and aggressive behavior. In an attempt to intercept the intercellular communication promoted by EVs, we recently developed a monovalent Fab fragment antibody directed against human CD9 tetraspanin and showed its effectiveness in blocking the internalization of melanoma cell-derived EVs and the nuclear transfer of their cargo proteins into recipient cells. Here, we employed the SW480/SW620 model to investigate the anti-cancer potential of the anti-CD9 Fab antibody. We first demonstrated that most EVs derived from SW620 cells contain CD9, making them potential targets. We then found that the anti-CD9 Fab antibody, but not the corresponding divalent antibody, prevented internalization of EVs from SW620 cells into SW480 cells, thereby inhibiting their phenotypic transformation, i.e., the change from a mesenchymal-like morphology to a rounded amoeboid-like shape with membrane blebbing, and thus preventing increased cell migration. Intercepting EV-mediated intercellular communication in the tumor niche with an anti-CD9 Fab antibody, combined with direct targeting of cancer cells, could lead to the development of new anti-cancer therapeutic strategies.
Assuntos
Neoplasias do Colo , Vesículas Extracelulares , Comunicação Celular , Neoplasias do Colo/patologia , Vesículas Extracelulares/metabolismo , Humanos , Fragmentos Fab das Imunoglobulinas/metabolismo , Tetraspanina 29/metabolismo , Microambiente TumoralRESUMO
BACKGROUND: Rodent and human prominin-1 are expressed in numerous adult epithelia and somatic stem cells. A report has shown that human PROMININ-1 carrying the AC133 epitope can be used to identify rare prostate basal stem cells (Richardson et al., J Cell Sci 2004; 117:35393545). Here we re-investigated its general expression in male reproductive tract including mouse and human prostate and in prostate cancer samples using various anti-prominin-1 antibodies. METHODS: The expression was monitored by immunohistochemistry and blotting. Murine tissues were stained with 13A4 monoclonal antibody (mAb) whereas human samples were examined either with the AC133 mAb recognizing the AC133 glycosylation-dependent epitope or 80B258 mAb directed against the PROMININ-1 polypeptide. RESULTS: Mouse prominin-1 was detected at the apical domain of epithelial cells of ductus deferens, seminal vesicles, ampullary glands, and all prostatic lobes. In human prostate, immunoreactivity for 80B258, but not AC133 was revealed at the apical side of some epithelial (luminal) cells, in addition to the minute population of AC133/80B258-positive cells found in basal compartment. Examination of prostate adenocarcinoma revealed the absence of 80B258 immunoreactivity in the tumor regions. However, it was found to be up-regulated in luminal cells in the vicinity of the cancer areas. CONCLUSIONS: Mouse prominin-1 is widely expressed in prostate whereas in human only some luminal cells express it, demonstrating nevertheless that its expression is not solely associated with basal stem cells. In pathological samples, our pilot evaluation shows that PROMININ-1 is down-regulated in the cancer tissues and up-regulated in inflammatory regions.
Assuntos
Antígenos CD/análise , Glicoproteínas/análise , Peptídeos/análise , Próstata/química , Células-Tronco/química , Antígeno AC133 , Idoso , Animais , Antígenos CD/genética , Células CACO-2 , Glicoproteínas/genética , Humanos , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Peptídeos/genética , Próstata/citologia , Neoplasias da Próstata/químicaRESUMO
We investigated the phenotype of hepatocellular carcinoma (HCC) in livers removed during transplantation after local ablation therapy by transarterial chemoembolization (TACE). This study involved 80 HCC nodules (40 treated with TACE and 40 not treated with local ablation before transplantation) observed in 64 explanted livers and included clinicopathological evaluations as well as single and double immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR) for cytokeratin 19 (CK19), epithelial cell adhesion molecule (EpCAM), neural cell adhesion molecule (NCAM), and CD133. HCCs with complete necrosis post-TACE without viable tumors were excluded from the analysis. Cholangiolar, glandular, or spindle cell areas suggestive of a mixed hepatocholangiocellular phenotype were seen in 14 post-TACE HCCs and in none of the non-TACE HCCs (P < 0.001). According to single-epitope immunohistochemistry of post-TACE HCCs, CD133, CK19, EpCAM, and NCAM were expressed in 14 (35%), 8 (20%), 12 (30%), and 8 (20%), respectively. Only EpCAM was detected in 4 non-TACE HCC cases (10%). RT-PCR experiments using tissues obtained by laser microdissection showed that 4 of 5 investigated post-TACE HCCs expressed at least 1 of the markers, which were coexpressed in 3 of 5 tumors, whereas CD133 and EpCAM were individually expressed in 2 non-TACE HCCs. Double immunostaining showed that CD133(+) cells frequently coexpressed CK19, EpCAM, or NCAM. Interestingly, the recurrence rate for patients with CD133(+) post-TACE HCC was significantly higher than the rate for patients with CD133(-) post-TACE HCC (P = 0.025). In conclusion, HCC with the combined hepatocholangiocellular phenotype appears to be more frequent in post-TACE HCC versus untreated HCC. Further studies are needed to investigate the potential relationships between TACE and HCC subpopulations with a chemoembolization-resistant phenotype and their clinical significance.
Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Transplante de Fígado/métodos , Antígeno AC133 , Adulto , Idoso , Antígenos CD/biossíntese , Antígenos de Neoplasias/metabolismo , Carcinoma Hepatocelular/etiologia , Moléculas de Adesão Celular/metabolismo , Molécula de Adesão da Célula Epitelial , Feminino , Glicoproteínas/biossíntese , Humanos , Queratina-19/biossíntese , Neoplasias Hepáticas/etiologia , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Moléculas de Adesão de Célula Nervosa/metabolismo , Peptídeos , Fenótipo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Resultado do TratamentoRESUMO
We isolated and expanded stem cells from dental pulp from extracted third molars using an innovative culture method consisting of low serum-containing medium supplemented with epidermal growth factor and platelet-derived growth factor BB. We evaluated the differentiation potential of these cells when they were growing either adherently or as micromass/spheroid cultures in various media. Undifferentiated and differentiated cells were analyzed by flow cytometry, immunocytochemistry and immunoblotting. The flow cytometry results showed that the dental pulp stem cells (DPSCs) were positive for mesenchymal stromal cell markers, but negative for hematopoietic markers. Immunocytochemical and/or immunoblotting analyses revealed the expression of numerous stem cell markers, including nanog, Sox2, nestin, Musashi-1 and nucleostemin, whereas they were negative for markers associated with differentiated neural, vascular and hepatic cells. Surprisingly, the cells were only slightly positive for α-smooth muscle actin, and a heterogeneous expression of CD146 was observed. When cultured in osteogenic media, they expressed osteonectin, osteopontin and procollagen I, and in micromass cultures, they produced collagen I. DPSCs cultured in TGF-ß1/3-supplemented media produced extracellular matrix typical of cartilaginous tissue. The addition of vascular endothelial growth factor to serum-free media resulted in the expression of endothelial markers. Interestingly, when cultured in neurogenic media, DPSCs exhibited de novo or upregulated markers of undifferentiated and differentiated neural cells. Collectively, our data show that DPSCs are self-renewing and able to express markers of bone, cartilage, vascular and neural tissues, suggesting their multipotential capacity. Their easy accessibility makes these cells a suitable source of somatic stem cells for tissue engineering.