RESUMO
Dormancy in cancer is a clinical state in which residual disease remains undetectable for a prolonged duration. At a cellular level, rare cancer cells cease proliferation and survive chemotherapy and disseminate disease. We created a suspension culture model of high-grade serous ovarian cancer (HGSOC) dormancy and devised a novel CRISPR screening approach to identify survival genes in this context. In combination with RNA-seq, we discovered the Netrin signaling pathway as critical to dormant HGSOC cell survival. We demonstrate that Netrin-1, -3, and its receptors are essential for low level ERK activation to promote survival, and that Netrin activation of ERK is unable to induce proliferation. Deletion of all UNC5 family receptors blocks Netrin signaling in HGSOC cells and compromises viability during the dormancy step of dissemination in xenograft assays. Furthermore, we demonstrate that Netrin-1 and -3 overexpression in HGSOC correlates with poor outcome. Specifically, our experiments reveal that Netrin overexpression elevates cell survival in dormant culture conditions and contributes to greater spread of disease in a xenograft model of abdominal dissemination. This study highlights Netrin signaling as a key mediator HGSOC cancer cell dormancy and metastasis.
High-grade serous ovarian cancer (or HGSOC for short) is the fifth leading cause of cancer-related deaths in women. It is generally diagnosed at an advanced stage of disease when the cancer has already spread to other parts of the body. Surgical removal of tumors and subsequent treatment with chemotherapy often reduces the signs and symptoms of the disease for a time but some cancer cells tend to survive so that patients eventually relapse. The HGSOC cells typically spread from the ovaries by moving through the liquid surrounding organs in the abdomen. The cells clump together and enter an inactive state known as dormancy that allows them to survive chemotherapy and low-nutrient conditions. Understanding how to develop new drug therapies that target dormant cancer cells is thought to be an important step in prolonging the life of HGSOC patients. Cancer cells are hardwired to multiply and grow, so Perampalam et al. reasoned that becoming dormant poses challenges for HGSOC cells, which may create unique vulnerabilities not shared by proliferating cancer cells. To find out more, the researchers used HGSOC cells that had been isolated from patients and grown in the laboratory. The team used a gene editing technique to screen HGSOC cells for genes required by the cells to survive when they are dormant. The experiments found that genes involved in a cell signaling pathway, known as Netrin signaling, were critical for the cells to survive. Previous studies have shown that Netrin signaling helps the nervous system form in embryos and inhibits a program of controlled cell death in some cancers. Perampalam et al. discovered that Netrins were present in the environment immediately surrounding dormant HGSOC cells. Human HGSOC patients with higher levels of Netrin gene expression had poorer prognoses than patients with lower levels of Netrin gene expression. Further experiments demonstrated that Netrins help dormant HGSOC cells to spread around the body. These findings suggest that Netrin signalling may provide useful targets for future drug therapies against dormant cells in some ovarian cancers. This could include repurposing drugs already in development or creating new inhibitors of this pathway.
Assuntos
Carcinoma Epitelial do Ovário , Sobrevivência Celular , Netrinas , Neoplasias Ovarianas , Transdução de Sinais , Humanos , Feminino , Animais , Linhagem Celular Tumoral , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/metabolismo , Carcinoma Epitelial do Ovário/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , Netrinas/metabolismo , Netrinas/genética , Camundongos , Netrina-1/metabolismo , Netrina-1/genética , Proliferação de Células , Receptores de Netrina/metabolismo , Receptores de Netrina/genéticaRESUMO
Clear cell renal cell carcinoma (ccRCC), the most common subtype of renal cell carcinoma, often leads to a poor prognosis due to metastasis. The investigation of N6-methyladenosine (m6A) methylation, a crucial RNA modification, and its role in ccRCC, particularly through the m6A reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), revealed significant insights. We found that IGF2BP2 was notably downregulated in ccRCC, which correlated with tumor aggressiveness and poor prognosis. Thus, IGFBP2 has emerged as an independent prognostic factor of ccRCC. Moreover, a strong positive correlation was observed between the expression of IGF2BP2 and Netrin-4. Netrin-4 was also downregulated in ccRCC, and its lower levels were associated with increased malignancy and poor prognosis. Overexpression of IGF2BP2 and Netrin-4 suppressed the invasion and migration of ccRCC cells, while Netrin-4 knockdown reversed these effects in ccRCC cell lines. RNA immunoprecipitation (RIP)-quantitative polymerase chain reaction validated the robust enrichment of Netrin-4 mRNA in anti-IGF2BP2 antibody immunoprecipitates. MeRlP showed significantly increased Netrin4 m6A levels after lGF2BP2 overexpression. Moreover, we found that IGF2BP2 recognized and bound to the m6A site within the coding sequence of Netrin-4, enhancing its mRNA stability. Collectively, these results showed that IGF2BP2 plays a suppressive role in the invasion and migration of ccRCC cells by targeting Netrin-4 in an m6A-dependent manner. These findings underscore the potential of IGF2BP2/Netrin-4 as a promising prognostic biomarker and therapeutic target in patients with ccRCC metastasis.
Assuntos
Carcinoma de Células Renais , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Neoplasias Renais , Invasividade Neoplásica , Netrinas , Proteínas de Ligação a RNA , Humanos , Netrinas/genética , Netrinas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/genética , Neoplasias Renais/patologia , Neoplasias Renais/metabolismo , Neoplasias Renais/genética , Prognóstico , Linhagem Celular Tumoral , Masculino , Adenosina/análogos & derivados , Adenosina/metabolismo , Feminino , Proliferação de Células , Pessoa de Meia-Idade , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismoRESUMO
Endometrial carcinoma (EC) is a common type of uterine cancer in developed countries, originating from the uterine epithelium. The incidence rate of EC in Taiwan has doubled from 2005. Cancer stem cells (CSCs) are a subpopulation of cancer cells that have high tumorigenicity and play a crucial role in the malignant processes of cancer. Targeting molecules associated with CSCs is essential for effective cancer treatments. This study delves into the role of Exosome component 5 (EXOSC5) in EC. Data from The Cancer Genome Atlas suggests a correlation between high EXOSC5 mRNA expression and unfavorable EC prognosis. EXOSC5 knockdown diminished EC-CSC self-renewal and reduced expression of key cancer stemness proteins, including c-MYC and SOX2. Intriguingly, this knockdown significantly curtailed tumorigenicity and CSC frequency in EC tumor spheres. A mechanistic examination revealed a reduction in netrin4 (NTN4) levels in EXOSC5-depleted EC cells. Moreover, NTN4 treatment amplified EC cell CSC activity and, when secreted, NTN4 partnered with integrin ß1, subsequently triggering the FAK/SRC axis to elevate c-MYC activity. A clear positive relation between EXOSC5 and NTN4 was evident in 93 EC tissues. In conclusion, EXOSC5 augments NTN4 expression, activating c-MYC via the integrin ß1/FAK/SRC pathway, offering potential avenues for EC diagnosis and treatment.
Assuntos
Neoplasias do Endométrio , Integrina beta1 , Humanos , Feminino , Integrina beta1/metabolismo , Transdução de Sinais/genética , Neoplasias do Endométrio/metabolismo , Células-Tronco Neoplásicas/metabolismo , Linhagem Celular Tumoral , Antígenos de Neoplasias/metabolismo , Proteínas de Ligação a RNA/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Netrinas/metabolismoRESUMO
The cyanotoxin cylindrospermopsin (CYN) has been postulated to cause neurotoxicity, although the studies in this concern are very few. In addition, some studies in vitro indicate its possible effects on development. Furthermore, pesticides can be present in the same environmental samples as cyanotoxins. Therefore, chlorpyrifos (CPF) has been one of the most common pesticides used worldwide. The aim of this report was to study the effects of CYN, isolated and in combination with CPF, in a developmental neurotoxicity in vitro model. The human neuroblastoma SH-SY5Y cell line was exposed during 6 days of differentiation to both toxics to study their effects on cell viability and neurite outgrowth. To further evaluate effects of both toxicants on cholinergic signaling, their agonistic and antagonistic activities on the α7 homomeric nicotinic acetylcholine receptor (nAChR) were studied upon acute exposure. Moreover, a transcriptomic analysis by qPCR was performed after 6 days of CYN-exposure during differentiation. The results showed a concentration-dependent decrease on both cell viability and neurite outgrowth for both toxics isolated, leading to effective concentration 20 (EC20) values of 0.35 µM and 0.097 µM for CYN on cell viability and neurite outgrowth, respectively, and 100 µM and 58 µM for CPF, while the combination demonstrated no significant variations. In addition, 95 µM and 285 µM CPF demonstrated to act as an antagonist to nicotine on the nAChR, although CYN up to 2.4 µM had no effect on the efficacy of these receptors. Additionally, the EC20 for CYN (0.097 µM) on neurite outgrowth downregulated expression of the 5 genes NTNG2 (netrin G2), KCNJ11 (potassium channel), SLC18A3 (vesicular acetylcholine transporter), APOE (apolipoprotein E), and SEMA6B (semaphorin 6B), that are all important for neuronal development. Thus, this study points out the importance of studying the effects of CYN in terms of neurotoxicity and developmental neurotoxicity.
Assuntos
Alcaloides , Clorpirifos , Toxinas de Cianobactérias , Neuroblastoma , Síndromes Neurotóxicas , Praguicidas , Humanos , Clorpirifos/toxicidade , Receptor Nicotínico de Acetilcolina alfa7/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Netrinas/metabolismo , Proteínas Ligadas por GPI/metabolismoRESUMO
Netrin G1 (NTNG1) is a member of the Netrin family and plays a crucial role in various human cancers. However, the molecular functions of NTNG1 in HCC and the underlying mechanisms remain unclear. HCC expression data was obtained from the GEO database and analyzed using various bioinformatics tools. The expression of NTNG1 in HCC tissues and liver cancer cells was evaluated through RT-qPCR and western blotting. Cells with stable NTNG1 overexpression and knockdown were established, and CCK-8, colony formation, and flow cytometry assays were conducted in vitro. The xenograft model was utilized to verify the tumorigenesis capacity of NTNG1 in vivo. IHC was employed to analyze the expression of NTNG1 and CD163 proteins. HCC-specific genes were screened, followed by functional enrichment and immune cell infiltration analysis. Finally, the Co-IP was used to detect the interaction between NTNG1 and N-cadherin. NTNG1 was highly expressed in HCC tissues and liver cancer cells, and associated with significantly poorer OS rates. In addition, NTNG1 overexpression in liver cancer cells significantly increased their proliferation, colony growth, invasion, migration, and EMT, while inhibiting apoptosis. Bioinformatics analyses indicated that NTNG1 was closely related to EMT and tumor infiltration. IHC staining revealed a positive correlation between NTNG1 expression and CD163 in HCC tissues. Additionally, an EMT inhibitor attenuated the expression levels of EMT-related markers and counteracted the effects of NTNG1 overexpression in liver cancer cells. This study is the first to identify NTNG1 as a potential therapeutic target in HCC, promoting tumor development and progression by regulating EMT.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Netrinas , Humanos , Carcinoma Hepatocelular/patologia , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Ligadas por GPI/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Netrinas/genética , Netrinas/metabolismoRESUMO
It was recently reported that netrin4 (Ntn4), a component of the extracellular matrix, when downregulated, is involved in the progression of several types of cancer, including breast cancer, colorectal tumours, neuroblastoma and gastric cancer. In the present study, the level of Ntn4 was examined in a public nonsmall cell lung cancer (NSCLC) dataset from the Netherlands Cancer Institute. This analysis revealed that the mRNA expression level of Ntn4 was lower in the samples of patients with NSCLC compared with that in the control samples. Consistent with the mRNA level, the protein level of Ntn4 was also found to be decreased in NSCLC cells. However, both the function of Ntn4 and the underlying mechanisms of Ntn4 downregulation in NSCLC have yet to be fully elucidated. As was anticipated, the overexpression of Ntn4 led to a marked decrease in the proliferation, migration and invasion of NSCLC cells. Notably, RNAbinding protein quaking 5 (Qki5) was found to exhibit antitumor activity in lung cancer, not only by enhancing the level of Ntn4 by binding to Ntn4 mRNA, but also by suppressing the proliferation, invasion and migration of NSCLC cells. However, Qki5 is known to be frequently downregulated in NSCLC. Moreover, the knockdown of Ntn4 was found to reverse the suppressive effects of Qki5 on NSCLC progression both in vitro and in vivo. Taken together, the findings of the present study demonstrate that Ntn4 is able to suppress the progression of NSCLC, and that the level of Ntn4 can be regulated by Qki5. Therefore, Ntn4 may be a novel diagnostic and therapeutic target for the treatment of NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , MicroRNAs , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , MicroRNAs/genética , Netrinas/genética , Netrinas/metabolismo , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
Cancer exerts pleiotropic, systemic effects on organisms, leading to health deterioration and eventually to organismal death. How cancer induces systemic effects on remote organs and the organism itself still remains elusive. Here we describe a role for NetrinB (NetB), a protein with a particularly well-characterized role as a tissue-level axon guidance cue, in mediating oncogenic stress-induced organismal, metabolic reprogramming as a systemic humoral factor. In Drosophila, Ras-induced dysplastic cells upregulate and secrete NetB. Inhibition of either NetB from the transformed tissue or its receptor in the fat body suppresses oncogenic stress-induced organismal death. NetB from the dysplastic tissue remotely suppresses carnitine biosynthesis in the fat body, which is critical for acetyl-CoA generation and systemic metabolism. Supplementation of carnitine or acetyl-CoA ameliorates organismal health under oncogenic stress. This is the first identification, to our knowledge, of a role for the Netrin molecule, which has been studied extensively for its role within tissues, in humorally mediating systemic effects of local oncogenic stress on remote organs and organismal metabolism.
Assuntos
Proteínas de Drosophila , Drosophila , Animais , Drosophila/metabolismo , Netrinas/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Acetilcoenzima A/metabolismo , Transdução de Sinais , Axônios/metabolismo , Fatores de Crescimento Neural/metabolismoRESUMO
BACKGROUND: Physical activity (PA) prior to and during pregnancy may have intergenerational effects on offspring health through placental epigenetic modifications. We are unaware of epidemiologic studies on longitudinal PA and placental DNA methylation. OBJECTIVES: We evaluated the association between PA before and during pregnancy and placental DNA methylation. METHODS: Placental tissues were obtained at delivery and methylation was measured using HumanMethylation450 Beadchips for participants in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singletons among 298 participants. Using the Pregnancy Physical Activity Questionnaire, women recalled periconception PA (past 12 mo) at 8-13 wk of gestation and PA since last visit at 4 follow-up visits at 16-22, 24-29, 30-33, and 34-37 wk. We conducted linear regression for associations of PA at each visit with methylation controlling for false discovery rate (FDR). Top 100 CpGs were queried for enrichment of functional pathways using Ingenuity Pathway Analysis. RESULTS: Periconception PA was significantly associated with 1 CpG site. PA since last visit for visits 1-4 was associated with 2, 2, 8, and 0 CpGs (log fold changes ranging from -0.0319 to 0.0080, after controlling for FDR). The largest change in methylation occurred at a site in TIMP2 , which is known to encode a protein critical for vasodilation, placentation, and uterine expansion during pregnancy (log fold change: -0.05; 95% CI: -0.06, -0.03 per metabolic equivalent of task-h/wk at 30-33 wk). Most significantly enriched pathways include cardiac hypertrophy signaling, B-cell receptor signaling, and netrin signaling. Significant CpGs and enriched pathways varied by visit. CONCLUSIONS: Recreational PA in the year prior and during pregnancy was associated with placental DNA methylation. The associated CpG sites varied based on timing of PA. If replicated, the findings may inform the mechanisms underlying the impacts of PA on placenta health. This study was registered at clinicaltrials.gov as NCT00912132.
Assuntos
Metilação de DNA , Epigenoma , Criança , Ilhas de CpG , Epigênese Genética , Exercício Físico , Feminino , Humanos , Netrinas/genética , Netrinas/metabolismo , Placenta/metabolismo , Gravidez , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismoRESUMO
Most genome-wide association study (GWAS)-identified breast cancer-associated causal variants remain uncharacterized. To provide a framework of understanding GWAS-identified variants to function, we performed a comprehensive study of noncoding regulatory variants at the NTN4 locus (12q22) and NTN4 gene in breast cancer etiology. We find that rs11836367 is the more likely causal variant, disrupting enhancer activity in both enhancer reporter assays and endogenous genome editing experiments. The protective T allele of rs11837367 increases the binding of GATA3 to the distal enhancer and up-regulates NTN4 expression. In addition, we demonstrate that loss of NTN4 gene in mice leads to tumor earlier onset, progression, and metastasis. We discover that NTN4, as a tumor suppressor, can attenuate the Wnt signaling pathway by directly binding to Wnt ligands. Our findings bridge the gaps among breast cancer-associated single-nucleotide polymorphisms, transcriptional regulation of NTN4, and breast cancer biology, which provides previously unidentified insights into breast cancer prediction and prevention.
Assuntos
Estudo de Associação Genômica Ampla , Neoplasias , Netrinas/metabolismo , Alelos , Animais , Predisposição Genética para Doença , Camundongos , Neoplasias/genética , Netrinas/genética , Polimorfismo de Nucleotídeo Único , Via de Sinalização Wnt/genéticaRESUMO
Epithelial remodelling plays a crucial role during development. The ability of epithelial sheets to temporarily lose their integrity as they fuse with other epithelial sheets underpins events such as the closure of the neural tube and palate. During fusion, epithelial cells undergo some degree of epithelial-mesenchymal transition (EMT), whereby cells from opposing sheets dissolve existing cell-cell junctions, degrade the basement membrane, extend motile processes to contact each other, and then re-establish cell-cell junctions as they fuse. Similar events occur when an epithelium is wounded. Cells at the edge of the wound undergo a partial EMT and migrate towards each other to close the gap. In this review, we highlight the emerging role of Netrins in these processes, and provide insights into the possible signalling pathways involved. Netrins are secreted, laminin-like proteins that are evolutionarily conserved throughout the animal kingdom. Although best known as axonal chemotropic guidance molecules, Netrins also regulate epithelial cells. For example, Netrins regulate branching morphogenesis of the lung and mammary gland, and promote EMT during Drosophila wing eversion. Netrins also control epithelial fusion during optic fissure closure and inner ear formation, and are strongly implicated in neural tube closure and secondary palate closure. Netrins are also upregulated in response to organ damage and epithelial wounding, and can protect against ischemia-reperfusion injury and speed wound healing in cornea and skin. Since Netrins also have immunomodulatory properties, and can promote angiogenesis and re-innervation, they hold great promise as potential factors in future wound healing therapies.
Assuntos
Células Epiteliais , Cicatrização , Animais , Células Epiteliais/metabolismo , Epitélio , Morfogênese , Netrinas/metabolismo , Cicatrização/fisiologiaRESUMO
Netrin-4, recognized in neural and vascular development, is highly expressed by mature endothelial cells. The function of this netrin-4 in vascular biology after development has remained unclear. We found that the expression of netrin-4 is highly regulated in endothelial cells and is important for quiescent healthy endothelium. Netrin-4 expression is upregulated in endothelial cells cultured under laminar flow conditions, while endothelial cells stimulated with tumor necrosis factor alpha resulted in decreased netrin-4 expression. Targeted reduction of netrin-4 in endothelial cells resulted in increased expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1. Besides, these endothelial cells were more prone to monocyte adhesion and showed impaired barrier function, measured with electric cell-substrate impedance sensing, as well as in an 'organ-on-a-chip' microfluidic system. Importantly, endothelial cells with reduced levels of netrin-4 showed increased expression of the senescence-associated markers cyclin-dependent kinase inhibitor-1 and -2A, an increased cell size and decreased ability to proliferate. Consistent with the gene expression profile, netrin-4 reduction was accompanied with more senescent associated ß-galactosidase activity, which could be rescued by adding netrin-4 protein. Finally, using human decellularized kidney extracellular matrix scaffolds, we found that pre-treatment of the scaffolds with netrin-4 increased numbers of endothelial cells adhering to the matrix, showing a pro-survival effect of netrin-4. Taken together, netrin-4 acts as an anti-senescence and anti-inflammation factor in endothelial cell function and our results provide insights as to maintain endothelial homeostasis and supporting vascular health.
Assuntos
Endotélio Vascular/metabolismo , Inflamação/prevenção & controle , Netrinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo , Células Cultivadas , Senescência Celular/fisiologia , Endotélio Vascular/patologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Netrinas/genéticaRESUMO
The basement membrane (BM) is a special type of extracellular matrix and presents the major barrier cancer cells have to overcome multiple times to form metastases. Here we show that BM stiffness is a major determinant of metastases formation in several tissues and identify netrin-4 (Net4) as a key regulator of BM stiffness. Mechanistically, our biophysical and functional analyses in combination with mathematical simulations show that Net4 softens the mechanical properties of native BMs by opening laminin node complexes, decreasing cancer cell potential to transmigrate this barrier despite creating bigger pores. Our results therefore reveal that BM stiffness is dominant over pore size, and that the mechanical properties of 'normal' BMs determine metastases formation and patient survival independent of cancer-mediated alterations. Thus, identifying individual Net4 protein levels within native BMs in major metastatic organs may have the potential to define patient survival even before tumour formation. The ratio of Net4 to laminin molecules determines BM stiffness, such that the more Net4, the softer the BM, thereby decreasing cancer cell invasion activity.
Assuntos
Membrana Basal/metabolismo , Fenômenos Mecânicos , Metástase Neoplásica , Fenômenos Biomecânicos , Linhagem Celular Tumoral , Humanos , Netrinas/metabolismoRESUMO
Pancreatic ductal adenocarcinoma (PDAC) has a poor 5-year survival rate and lacks effective therapeutics. Therefore, it is of paramount importance to identify new targets. Using multiplex data from patient tissue, three-dimensional coculturing in vitro assays, and orthotopic murine models, we identified Netrin G1 (NetG1) as a promoter of PDAC tumorigenesis. We found that NetG1+ cancer-associated fibroblasts (CAF) support PDAC survival, through a NetG1-mediated effect on glutamate/glutamine metabolism. Also, NetG1+ CAFs are intrinsically immunosuppressive and inhibit natural killer cell-mediated killing of tumor cells. These protumor functions are controlled by a signaling circuit downstream of NetG1, which is comprised of AKT/4E-BP1, p38/FRA1, vesicular glutamate transporter 1, and glutamine synthetase. Finally, blocking NetG1 with a neutralizing antibody stunts in vivo tumorigenesis, suggesting NetG1 as potential target in PDAC. SIGNIFICANCE: This study demonstrates the feasibility of targeting a fibroblastic protein, NetG1, which can limit PDAC tumorigenesis in vivo by reverting the protumorigenic properties of CAFs. Moreover, inhibition of metabolic proteins in CAFs altered their immunosuppressive capacity, linking metabolism with immunomodulatory function.See related commentary by Sherman, p. 230.This article is highlighted in the In This Issue feature, p. 211.
Assuntos
Adenocarcinoma/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Netrinas/metabolismo , Neoplasias Pancreáticas/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Terapia de Imunossupressão , Apoio Nutricional , Microambiente TumoralRESUMO
Frequently reported neurotoxic sequelae of cancer treatment include cognitive deficits and sensorimotor abnormalities that have long-lasting negative effects on the quality of life of an increasing number of cancer survivors. The underlying mechanisms are not fully understood and there is no effective treatment. We show here that cisplatin treatment of mice not only caused cognitive dysfunction but also impaired sensorimotor function. These functional deficits are associated with reduced myelin density and complexity in the cingulate and sensorimotor cortex. At the ultrastructural level, myelin abnormalities were characterized by decompaction. We used this model to examine the effect of bexarotene, an agonist of the RXR-family of nuclear receptors. Administration of only five daily doses of bexarotene after completion of cisplatin treatment was sufficient to normalize myelin density and fiber coherency and to restore myelin compaction in cingulate and sensorimotor cortex. Functionally, bexarotene normalized performance of cisplatin-treated mice in tests for cognitive and sensorimotor function. RNAseq analysis identified the TR/RXR pathway as one of the top canonical pathways activated by administration of bexarotene to cisplatin-treated mice. Bexarotene also activated neuregulin and netrin pathways that are implicated in myelin formation/maintenance, synaptic function and axonal guidance. In conclusion, short term treatment with bexarotene is sufficient to reverse the adverse effects of cisplatin on white matter structure, cognitive function, and sensorimotor performance. These encouraging findings warrant further studies into potential clinical translation and the underlying mechanisms of bexarotene for chemobrain.
Assuntos
Antineoplásicos/farmacologia , Bexaroteno/farmacologia , Cisplatino/toxicidade , Cognição/efeitos dos fármacos , Giro do Cíngulo/efeitos dos fármacos , Bainha de Mielina/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Córtex Sensório-Motor/efeitos dos fármacos , Animais , Antineoplásicos/toxicidade , Comprometimento Cognitivo Relacionado à Quimioterapia/metabolismo , Comprometimento Cognitivo Relacionado à Quimioterapia/patologia , Comprometimento Cognitivo Relacionado à Quimioterapia/fisiopatologia , Marcha/efeitos dos fármacos , Perfilação da Expressão Gênica , Giro do Cíngulo/metabolismo , Giro do Cíngulo/patologia , Giro do Cíngulo/fisiopatologia , Camundongos , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Bainha de Mielina/ultraestrutura , Netrinas/efeitos dos fármacos , Netrinas/genética , Netrinas/metabolismo , Neurregulinas/efeitos dos fármacos , Neurregulinas/genética , Neurregulinas/metabolismo , Teste de Campo Aberto , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Córtex Pré-Frontal/fisiopatologia , RNA-Seq , Receptores X de Retinoides/efeitos dos fármacos , Receptores X de Retinoides/genética , Receptores X de Retinoides/metabolismo , Córtex Sensório-Motor/metabolismo , Córtex Sensório-Motor/patologia , Córtex Sensório-Motor/fisiopatologia , Substância Branca/efeitos dos fármacos , Substância Branca/metabolismo , Substância Branca/patologiaRESUMO
Breast cancer genome-wide association studies (GWASs) have identified 150 genomic risk regions containing more than 13,000 credible causal variants (CCVs). The CCVs are predominantly noncoding and enriched in regulatory elements. However, the genes underlying breast cancer risk associations are largely unknown. Here, we used genetic colocalization analysis to identify loci at which gene expression could potentially explain breast cancer risk phenotypes. Using data from the Breast Cancer Association Consortium (BCAC) and quantitative trait loci (QTL) from the Genotype-Tissue Expression (GTEx) project and The Cancer Genome Project (TCGA), we identify shared genetic relationships and reveal novel associations between cancer phenotypes and effector genes. Seventeen genes, including NTN4, were identified as potential mediators of breast cancer risk. For NTN4, we showed the rs61938093 CCV at this region was located within an enhancer element that physically interacts with the NTN4 promoter, and the risk allele reduced NTN4 promoter activity. Furthermore, knockdown of NTN4 in breast cells increased cell proliferation in vitro and tumor growth in vivo. These data provide evidence linking risk-associated variation to genes that may contribute to breast cancer predisposition.
Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Proteínas de Neoplasias/genética , Netrinas/genética , Alelos , Animais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Elementos Facilitadores Genéticos , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Genômica/métodos , Xenoenxertos , Humanos , Células MCF-7 , Camundongos , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Netrinas/metabolismo , Fenótipo , Locos de Características Quantitativas , RiscoRESUMO
The anchor cell (AC) in C. elegans secretes an epidermal growth factor (EGF) homolog that induces adjacent vulval precursor cells (VPCs) to differentiate. The EGF receptor in the nearest VPC sequesters the limiting EGF amounts released by the AC to prevent EGF from spreading to distal VPCs. Here, we show that not only EGFR localization in the VPCs but also EGF polarity in the AC is necessary for robust fate specification. The AC secretes EGF in a directional manner towards the nearest VPC. Loss of AC polarity causes signal spreading and, when combined with MAPK pathway hyperactivation, the ectopic induction of distal VPCs. In a screen for genes preventing distal VPC induction, we identified sra-9 and nlp-26 as genes specifically required for polarized EGF secretion. sra-9(lf) and nlp-26(lf) mutants exhibit errors in vulval fate specification, reduced precision in VPC to AC alignment and increased variability in MAPK activation. sra-9 encodes a seven-pass transmembrane receptor acting in the AC and nlp-26 a neuropeptide-like protein expressed in the VPCs. SRA-9 and NLP-26 may transduce a feedback signal to channel EGF secretion towards the nearest VPC.
Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Vulva/metabolismo , Animais , Animais Geneticamente Modificados/crescimento & desenvolvimento , Animais Geneticamente Modificados/metabolismo , Sistemas CRISPR-Cas/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/antagonistas & inibidores , Proteínas de Caenorhabditis elegans/genética , Fator de Crescimento Epidérmico/antagonistas & inibidores , Fator de Crescimento Epidérmico/genética , Receptores ErbB/metabolismo , Feminino , Edição de Genes , Larva/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutagênese , Netrinas/genética , Netrinas/metabolismo , Interferência de RNA , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/metabolismo , Vulva/citologia , Vulva/crescimento & desenvolvimento , Proteínas Ativadoras de ras GTPase/antagonistas & inibidores , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/metabolismoRESUMO
Fluoxetine is one of the most promising drugs for improving clinical outcome in patients with ischemic stroke. This in vivo study investigated the hypothesis that fluoxetine may affect HIF-1α-Netrin/VEGF cascade, angiogenesis and neuroprotection using a rat model of transient middle cerebral artery occlusion (tMCAO). The rats were given fluoxetine or saline after tMCAO for 4 weeks. Then, protein expression of HIF-1α-Netrin/VEGF cascade was examined at 1, 2, 4 weeks after tMCAO. In vivo synchrotron radiation were performed to observe microangiography of ischemic brain after 4 weeks of tMCAO. The infarct size and neurobehavioral test were carried out 1 to 4 weeks after tMCAO. Results revealed that HIF-1α expression was upregulated in fluoxetine-treated group. Similarly, fluoxetine increased protein expression of Netrin and its receptor DCC, VEGF and its receptor VEGFR. Synchrotron radiation angiography revealed more branches in fluoxetine-treated rats. We found no difference of infarct volume between fluoxetine and saline treated rats after 1 week of tMCAO, and ischemia-induced brain atrophy volume in fluoxetine-treated group was attenuated after 4 weeks of tMCAO. Neurological deficits were improved in fluoxetine-treated rats at 3 and 4 weeks after tMCAO. Our results indicated that fluoxetine could upregulate protein expression of HIF-1α-Netrin/VEGF cascade, promote angiogenesis, and improve long-term functional recovery after ischemic stroke.
Assuntos
Fluoxetina/uso terapêutico , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Neovascularização Fisiológica/fisiologia , Netrinas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Modelos Animais de Doenças , Fluoxetina/farmacologia , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Neuroproteção/fisiologia , Ratos , Ratos Sprague-Dawley , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Resultado do TratamentoRESUMO
Recent cancer studies have found that the netrin family of proteins plays vital roles in the development of some cancers. However, the functions of the many variants of these proteins in cancer remain incompletely understood. In this work, we used the most comprehensive database available, including more than 10000 samples across more than 30 tumor types, to analyze the six members of the netrin family. We performed comprehensive analysis of genetic change and expression of the netrin genes and analyzed epigenetic and pathway relationships, as well as the correlation of expression of these proteins with drug sensitivity. Although the mutation rate of the netrin family is low in pan-cancer, among the tumor patients with netrin mutations, the highest number are Uterine Corpus Endometrial Carcinoma patients, accounting for 13.6% of cases (54 of 397). Interestingly, the highest mutation rate of a netrin family member is 38% for NTNG1 (152 of 397). Netrin proteins may participate in the development of endocrine-related tumors and sex hormone-targeting organ tumors. Additionally, the participation of NTNG1 and NTNG2 in various cancers shows their potential for use as new tumor markers and therapeutic targets. This analysis provides a broad molecular perspective of this protein family and suggests some new directions for the treatment of cancer.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias/genética , Netrinas/genética , Neoplasias do Endométrio/genética , Epigênese Genética , Feminino , Proteínas Ligadas por GPI/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Estimativa de Kaplan-Meier , Metilação , Taxa de Mutação , Neoplasias/tratamento farmacológico , Neoplasias/mortalidade , Netrinas/metabolismo , Locos de Características Quantitativas/genéticaRESUMO
Netrin is a prototypical axon guidance cue. Structural studies have revealed how netrin interacts with the deleted in colorectal cancer (DCC) receptor, other receptors, and co-factors for signaling. Recently, genetic studies suggested that netrin is involved in neuronal haptotaxis, which requires a reversible adhesion process. Structural data indicate that netrin can also mediate trans-adhesion between apposing cells decorated with its receptors on the condition that the auxiliary guidance cue draxin is present. Here, we propose that netrin is involved in conditional adhesion, a reversible and localized process that can contribute to cell adhesion and migration. We suggest that netrin-mediated adhesion and signaling are linked, and that local environmental factors in the ventricular zone, the floor plate, or other tissues coordinate its function.
Assuntos
Receptor DCC/metabolismo , Netrinas/metabolismo , Transdução de Sinais , Animais , Adesão Celular , Receptor DCC/química , Humanos , Netrinas/química , Netrinas/genéticaRESUMO
Netrin-G ligand-3 (NGL-3) is a postsynaptic adhesion molecule known to directly interact with the excitatory postsynaptic scaffolding protein postsynaptic density-95 (PSD-95) and trans-synaptically with leukocyte common antigen-related (LAR) family receptor tyrosine phosphatases to regulate presynaptic differentiation. Although NGL-3 has been implicated in the regulation of excitatory synapse development by in vitro studies, whether it regulates synapse development or function, or any other features of brain development and function, is not known. Here, we report that mice lacking NGL-3 (Ngl3-/- mice) show markedly suppressed normal brain development and postnatal survival and growth. A change of the genetic background of mice from pure to hybrid minimized these developmental effects but modestly suppressed N-methyl-D-aspartate (NMDA) receptor (NMDAR)-mediated synaptic transmission in the hippocampus without affecting synapse development, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor (AMPAR)-mediated basal transmission, and presynaptic release. Intriguingly, long-term depression (LTD) was near-completely abolished in Ngl3-/- mice, and the Akt/glycogen synthase kinase 3ß (GSK3ß) signaling pathway, known to suppress LTD, was abnormally enhanced. In addition, pharmacological inhibition of Akt, but not activation of NMDARs, normalized the suppressed LTD in Ngl3-/- mice, suggesting that Akt hyperactivity suppresses LTD. Ngl3-/- mice displayed several behavioral abnormalities, including hyperactivity, anxiolytic-like behavior, impaired spatial memory, and enhanced seizure susceptibility. Among them, the hyperactivity was rapidly improved by pharmacological NMDAR activation. These results suggest that NGL-3 regulates brain development, Akt/GSK3ß signaling, LTD, and locomotive and cognitive behaviors.