RESUMEN
The DREAM complex orchestrates cell quiescence and the cell cycle. However, how the DREAM complex is deregulated in cancer remains elusive. Here, we report that PAF (PCLAF/KIAA0101) drives cell quiescence exit to promote lung tumorigenesis by remodeling the DREAM complex. PAF is highly expressed in lung adenocarcinoma (LUAD) and is associated with poor prognosis. Importantly, Paf knockout markedly suppressed LUAD development in mouse models. PAF depletion induced LUAD cell quiescence and growth arrest. PAF is required for the global expression of cell-cycle genes controlled by the repressive DREAM complex. Mechanistically, PAF inhibits DREAM complex formation by binding to RBBP4, a core DREAM subunit, leading to transactivation of DREAM target genes. Furthermore, pharmacological mimicking of PAF-depleted transcriptomes inhibited LUAD tumor growth. Our results unveil how the PAF-remodeled DREAM complex bypasses cell quiescence to promote lung tumorigenesis and suggest that the PAF-DREAM axis may be a therapeutic vulnerability in lung cancer.
Asunto(s)
Carcinogénesis/genética , Proteínas de Unión al ADN/genética , Proteínas de Interacción con los Canales Kv/genética , Neoplasias Pulmonares/genética , Pulmón/patología , Proteínas Represoras/genética , Células A549 , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/patología , Animales , Carcinogénesis/patología , División Celular/genética , Línea Celular , Línea Celular Tumoral , Proliferación Celular/genética , Femenino , Humanos , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Desnudos , Células 3T3 NIH , Activación Transcripcional/genética , Transcriptoma/genéticaRESUMEN
BACKGROUND AND AIMS: How Wnt signaling is orchestrated in liver regeneration and tumorigenesis remains elusive. Recently, we identified transmembrane protein 9 (TMEM9) as a Wnt signaling amplifier. APPROACH AND RESULTS: TMEM9 facilitates v-ATPase assembly for vesicular acidification and lysosomal protein degradation. TMEM9 is highly expressed in regenerating liver and hepatocellular carcinoma (HCC) cells. TMEM9 expression is enriched in the hepatocytes around the central vein and acutely induced by injury. In mice, Tmem9 knockout impairs hepatic regeneration with aberrantly increased adenomatosis polyposis coli (Apc) and reduced Wnt signaling. Mechanistically, TMEM9 down-regulates APC through lysosomal protein degradation through v-ATPase. In HCC, TMEM9 is overexpressed and necessary to maintain ß-catenin hyperactivation. TMEM9-up-regulated APC binds to and inhibits nuclear translocation of ß-catenin, independent of HCC-associated ß-catenin mutations. Pharmacological blockade of TMEM9-v-ATPase or lysosomal degradation suppresses Wnt/ß-catenin through APC stabilization and ß-catenin cytosolic retention. CONCLUSIONS: Our results reveal that TMEM9 hyperactivates Wnt signaling for liver regeneration and tumorigenesis through lysosomal degradation of APC.
Asunto(s)
Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Proteínas de la Membrana/metabolismo , ATPasas de Translocación de Protón Vacuolares/metabolismo , Proteína de la Poliposis Adenomatosa del Colon/genética , Animales , Tetracloruro de Carbono/administración & dosificación , Tetracloruro de Carbono/toxicidad , Carcinogénesis/patología , Carcinoma Hepatocelular/genética , Núcleo Celular/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Células HEK293 , Células Hep G2 , Humanos , Leupeptinas/farmacología , Neoplasias Hepáticas/genética , Regeneración Hepática , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Proteolisis/efectos de los fármacos , Vía de Señalización Wnt , Ensayos Antitumor por Modelo de Xenoinjerto , beta Catenina/genética , beta Catenina/metabolismoRESUMEN
Tumor cell plasticity contributes to intratumoral heterogeneity and therapy resistance. Through cell plasticity, some lung adenocarcinoma (LUAD) cells transform into neuroendocrine (NE) tumor cells. However, the mechanisms of NE cell plasticity remain unclear. CRACD (capping protein inhibiting regulator of actin dynamics), a capping protein inhibitor, is frequently inactivated in cancers. CRACD knockout (KO) is sufficient to de-repress NE-related gene expression in the pulmonary epithelium and LUAD cells. In LUAD mouse models, Cracd KO increases intratumoral heterogeneity with NE gene expression. Single-cell transcriptomic analysis showed that Cracd KO-induced NE cell plasticity is associated with cell de-differentiation and stemness-related pathway activation. The single-cell transcriptomic analysis of LUAD patient tumors recapitulates that the distinct LUAD NE cell cluster expressing NE genes is co-enriched with impaired actin remodeling. This study reveals the crucial role of CRACD in restricting NE cell plasticity that induces cell de-differentiation of LUAD.
Asunto(s)
Adenocarcinoma del Pulmón , Plasticidad de la Célula , Neoplasias Pulmonares , Células Neuroendocrinas , Animales , Humanos , Ratones , Adenocarcinoma del Pulmón/patología , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Células Neuroendocrinas/metabolismo , Células Neuroendocrinas/patología , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismoRESUMEN
Parkinson's disease (PD) is the second leading neurodegenerative disease, and is known to be induced by environmental factors or genetic mutations. Among the verified genetic mutations of PD, Parkin, isolated from the PARK2 locus, shows an autosomal recessive inheritance pattern and is known to be an E3 ligase. However, the physiological target of Parkin and the molecular mechanism of Parkin-deficiency-induced PD have not been clearly demonstrated until now. It has recently been proposed that inflammation, suggesting as a causal factor for PD, is enhanced by Parkin deficiency. Thus, we examined the relationship between inflammation-related factors and Parkin. Here, we provide the evidence that Parkin suppresses inflammation and cytokine-induced cell death by promoting the proteasomal degradation of TRAF2/6 (TNF-α receptor-associated factor 2/6). Overexpression of Parkin can reduce the half-lives of TRAF2 and TRAF6, whereas si-Parkin can extend them. However, mutant Parkins did not alter the expression of TRAF2/6. Thus, loss of Parkin enhances sensitivity to TNF-α- or IL-1ß-induced JNK activation and NF-κB activation. Indeed, si-Parkin-induced apoptosis is suppressed by the knockdown of TRAF6 or TRAF2. We also observed elevated expression levels of TRAF6 and a reduction of IκB in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced PD mouse model. Moreover, elevated expression levels or aggregation of TRAF6 were detected in approximately half of the human PD tissues (7/15 cases) and 2 cases, respectively. In addition, TRAF6 and Parkin expression levels show a reverse relationship in human PD tissues. Our results strongly suggest that the reduction of Parkin or overexpression of TRAF2/6 by chronic inflammation would be the reason for occurrence of PD.
Asunto(s)
Enfermedad de Parkinson/metabolismo , Factor 2 Asociado a Receptor de TNF/metabolismo , Factor 6 Asociado a Receptor de TNF/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Anciano , Anciano de 80 o más Años , Animales , Muerte Celular , Citocinas/metabolismo , Citosol/metabolismo , Femenino , Células HCT116 , Humanos , Masculino , Ratones , Ratones Endogámicos ICR , Mutación , Complejo de la Endopetidasa Proteasomal/metabolismo , Transducción de Señal , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Tumor cell plasticity contributes to intratumoral heterogeneity and therapy resistance. Through cell plasticity, lung adenocarcinoma (LUAD) cells transform into neuroendocrinal (NE) tumor cells. However, the mechanisms of NE cell plasticity remain unclear. CRACD, a capping protein inhibitor, is frequently inactivated in cancers. CRACD knock-out (KO) de-represses NE-related gene expression in the pulmonary epithelium and LUAD cells. In LUAD mouse models, Cracd KO increases intratumoral heterogeneity with NE gene expression. Single-cell transcriptomic analysis showed that Cracd KO-induced NE plasticity is associated with cell de-differentiation and activated stemness-related pathways. The single-cell transcriptomes of LUAD patient tumors recapitulate that the distinct LUAD NE cell cluster expressing NE genes is co-enriched with SOX2, OCT4, and NANOG pathway activation, and impaired actin remodeling. This study reveals an unexpected role of CRACD in restricting NE cell plasticity that induces cell de-differentiation, providing new insights into cell plasticity of LUAD.
RESUMEN
The influenza A virus (IAV) has caused several pandemics, and therefore there are many ongoing efforts to identify novel antiviral therapeutic strategies including vaccines and antiviral drugs. However, influenza viruses continuously undergo antigenic drift and shift, resulting in the emergence of mutated viruses. In turn, this decreases the efficiency of existing vaccines and antiviral drugs to control IAV infection. Therefore, this study sought to identify alternative therapeutic strategies targeting host cell factors rather than viruses to avoid infection by mutated viruses. Particularly, we investigated the role of KIF20A that is one of kinesin superfamily proteins in the replication of IAV. The KIF20A increased viral protein levels in IAV-infected cells by regulating the initial entry stage during viral infection. Furthermore, the KIF20A inhibitor significantly suppressed viral replication, which protected mice from morbidity and mortality. Therefore, our findings demonstrated that KIF20A is highly involved in the viral replication process and viral propagation both in vitro and in vivo, and could thus be used as a target for the development of novel antiviral drugs.
Asunto(s)
Virus de la Influenza A , Gripe Humana , Ratones , Animales , Humanos , Internalización del Virus , Replicación Viral , Antivirales/farmacologíaRESUMEN
Genetic mutation of α-synuclein (α-SYN) is clearly verified as the causal factor of human and mouse Parkinson's disease. However, biological function of α-SYN has not been clearly demonstrated until now. In this investigation, we reveal that α-SYN is a co-regulator of growth factor-induced AKT activation. Elimination of SYN reduces the IGF-1-mediated AKT activation. Similarly, mutant SYN suppresses the IGF-1-induced AKT activation. Wild-type SYN can interact with AKT and enhance the solubility and plasma localization of AKT in response to IGF-1, whereas mutant α-SYNs do not interact with AKT. In addition, elevated expression of SYN blocks the AKT activation. We also find that si-RNA against α-SYN abolished the protective effect of IGF-1 against DNA damage-induced apoptosis. Our result strongly indicates that Parkinson's disease, induced by α-SYN mutation, is evoked by deregulation of the AKT-signaling cascade.
Asunto(s)
Factor I del Crecimiento Similar a la Insulina/metabolismo , Enfermedad de Parkinson/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/fisiología , alfa-Sinucleína/metabolismo , Línea Celular , Humanos , Factor I del Crecimiento Similar a la Insulina/antagonistas & inhibidores , Enfermedad de Parkinson/enzimología , Enfermedad de Parkinson/fisiopatología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , alfa-Sinucleína/genéticaRESUMEN
Mucins are high molecular-weight epithelial glycoproteins and are implicated in many physiological processes, including epithelial cell protection, signaling transduction, and tissue homeostasis. Abnormality of mucus expression and structure contributes to biological properties related to human cancer progression. Tumor growth sites induce inhospitable conditions. Many kinds of research suggest that mucins provide a microenvironment to avoid hypoxia, acidic, and other biological conditions that promote cancer progression. Given that the mucus layer captures growth factors or cytokines, we propose that mucin helps to ameliorate inhospitable conditions in tumor-growing sites. Additionally, the composition and structure of mucins enable them to mimic the surface of normal epithelial cells, allowing tumor cells to escape from immune surveillance. Indeed, human cancers such as mucinous carcinoma, show a higher incidence of invasion to adjacent organs and lymph node metastasis than do non-mucinous carcinoma. In this minireview, we discuss how mucin provides a tumor-friendly environment and contributes to increased cancer malignancy in mucinous carcinoma. [BMB Reports 2021; 54(7): 344-355].
Asunto(s)
Mucinas/metabolismo , Neoplasias/metabolismo , Biomarcadores de Tumor/metabolismo , Humanos , Mucina-1/metabolismo , Mucinas/fisiología , Células Madre Neoplásicas/metabolismo , Microambiente TumoralRESUMEN
Organoids mimic the physiologic and pathologic events of organs. However, no consensus on esophageal organoid (EO) culture methods has been reached. Moreover, organoid models reproducing esophageal squamous cell carcinoma (ESCC) initiation have been unavailable. Herein, we sought to develop an esophageal minimum essential organoid culture medium (E-MEOM) for culturing murine EOs and establishing an early ESCC model. We formulated E-MEOM to grow EOs from a single cell with clonal expansion, maintenance, and passage. We found that EOs cultured in E-MEOM were equivalent to the esophageal epithelium by histological analysis and transcriptomic study. Trp53 knockout and Kras G12D expression in EOs induced the development of esophageal squamous neoplasia, an early lesion of ESCC. Here we propose the new formula for EO culture with minimum components and the organoid model recapitulating ESCC initiation, laying the foundation for ESCC research and drug discovery.
RESUMEN
Although chemotherapy is a key cancer treatment, many chemotherapeutic drugs produce chronic neuropathic pain, called chemotherapy-induced neuropathic pain (CINP), which is a dose-limiting adverse effect. To date, there is no medicine that prevents CINP in cancer patients and survivors. We determined whether blockers of the canonical Wnt signaling pathway prevent CINP. Neuropathic pain was induced by intraperitoneal injection of paclitaxel (PAC) on four alternate days in male Sprague-Dawley rats or male Axin2-LacZ knock-in mice. XAV-939, LGK-974, and iCRT14, Wnt/ß-catenin blockers, were administered intraperitoneally as a single or multiple doses before or after injury. Mechanical allodynia, phosphoproteome profiling, Wnt ligands, and inflammatory mediators were measured by von Frey filament, phosphoproteomics, reverse transcription-polymerase chain reaction, and Western blot analysis. Localization of ß-catenin was determined by immunohistochemical analysis in the dorsal root ganglia (DRGs) in rats and human. Our phosphoproteome profiling of CINP rats revealed significant phosphorylation changes in Wnt signaling components. Importantly, repeated systemic injections of XAV-939 or LGK-974 prevented the development of CINP in rats. In addition, XAV-939, LGK-974, and iCRT14 ameliorated CINP. PAC increased Wnt3a and Wnt10a, activated ß-catenin in DRG, and increased monocyte chemoattractant protein-1 and interleukin-1ß in DRG. PAC also upregulated rAxin2 in mice. Furthermore, ß-catenin was expressed in neurons, including calcitonin gene-related protein-expressing neurons and satellite cells in rat and human DRG. In conclusion, chemotherapy increases Wnt3a, Wnt10a, and ß-catenin in DRG and their pharmacological blockers prevent and ameliorate CINP, suggesting a target for the prevention and treatment of CINP.
Asunto(s)
Neuralgia/inducido químicamente , Proteínas Wnt/antagonistas & inhibidores , Proteína Wnt3A/antagonistas & inhibidores , beta Catenina/antagonistas & inhibidores , Animales , Western Blotting , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Ganglios Espinales/patología , Humanos , Hiperalgesia/tratamiento farmacológico , Masculino , Ratones , Ratones Transgénicos , Neuralgia/prevención & control , Paclitaxel/farmacología , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/efectos de los fármacos , Proteínas Wnt/metabolismo , Proteína Wnt3A/metabolismoRESUMEN
Wnt/ß-catenin signaling is implicated in many physiological processes, including development, tissue homeostasis, and tissue regeneration. In human cancers, Wnt/ß-catenin signaling is highly activated, which has led to the development of various Wnt signaling inhibitors for cancer therapies. Nonetheless, the blockade of Wnt signaling causes side effects such as impairment of tissue homeostasis and regeneration. Recently, several studies have identified cancer-specific Wnt signaling regulators. In this review, we discuss the Wnt inhibitors currently being used in clinical trials and suggest how additional cancer-specific regulators could be utilized to treat Wnt signaling-associated cancer.
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Neoplasias/metabolismo , Proteínas Wnt/metabolismo , Vía de Señalización Wnt/fisiología , beta Catenina/metabolismo , Animales , HumanosRESUMEN
T-cell-based cancer immunotherapies, such as immune checkpoint blockers (ICBs) and chimeric antigen receptor (CAR)-Tcells, have significant anti-tumor effects against certain types of cancer, providing a new paradigm for cancer treatment. However, the activity of tumor infiltrating T-cells (TILs) can be effectively neutralized in the tumor microenvironment (TME) of most solid tumors, rich in various immunosuppressive factors and cells. Therefore, to improve the clinical outcomes of established T-cell-based immunotherapy, adjuvants that can comprehensively relieve multiple immunosuppressive mechanisms of TME are needed. In this regard, recent studies have revealed that metformin has several beneficial effects on anti-tumor immunity. In this mini-review, we understand the immunosuppressive properties of TME and how metformin comprehensively enhances anti-tumor immunity. Finally, we will discuss this old friend's potential as an adjuvant for cancer immunotherapy. [BMB Reports 2020; 53(10): 512-520].
Asunto(s)
Linfocitos Infiltrantes de Tumor/efectos de los fármacos , Metformina/farmacología , Metformina/uso terapéutico , Humanos , Inmunoterapia/métodos , Células Asesinas Naturales , Linfocitos Infiltrantes de Tumor/metabolismo , Metformina/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Receptores Quiméricos de Antígenos , Linfocitos T , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunologíaRESUMEN
The strong tumor suppressor p53 shows loss of function in large portion of human cancer. In addition to genetic mutation, biological function of p53 is suppressed by signaling distortion or elevated expression of p53 inhibitors (such as overexpression of MDM2 or deletion of p14/ARF). In this study, we demonstrate that K-Ras, a frequently altered oncogene in human cancers including pancreatic cancer (about 80%), colon cancer (45%) and lung cancer (45%), suppresses p53. Based on this fact, we perform Western blot analysis-based chemical screening to isolate a K-Ras-specific activator of p53. From 117 kinds of chemicals (34 kinds of natural compounds that are obtained from herbal plants, 53 kinds of flavonoid, and 31 kinds of phenolic compounds), we find that quercetin works as an activator of p53 in K-Ras mutated cells but not in wild-type cells. Treatment with quercetin can induce p53 target genes such as PUMA and p21. These results suggest that although quercetin has limitations for use as a therapeutic drug due to its broad effects, specific function of it on K-Ras-p53 may be useful for K-Ras-induced cancer prevention and therapy through further development.
Asunto(s)
Neoplasias de la Mama/patología , Neoplasias del Colon/patología , Neoplasias Pulmonares/patología , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Quercetina/farmacología , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteínas ras/antagonistas & inhibidores , Antioxidantes/farmacología , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Western Blotting , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/metabolismo , Técnicas Químicas Combinatorias , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas p21(ras) , Tecnología Farmacéutica , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismoRESUMEN
Epithelial integrity is maintained by the cytoskeleton and through cell adhesion. However, it is not yet known how a deregulated cytoskeleton is associated with cancer. We identified cancer-related regulator of actin dynamics (CRAD) as frequently mutated or transcriptionally downregulated in colorectal cancer. We found that CRAD stabilizes the cadherin-catenin-actin complex via capping protein inhibition. The loss of CRAD inhibits F-actin polymerization and subsequently disrupts the cadherin-catenin-actin complex, which leads to ß-catenin release and Wnt signalling hyperactivation. In mice, CRAD knockout induces epithelial cell integrity loss and Wnt signalling activation, resulting in the development of intestinal mucinous adenoma. With APC mutation, CRAD knockout initiates and accelerates mucinous and invasive adenoma development in the colorectum. These results define CRAD as a tumour suppressor, the inactivation of which deregulates the cytoskeleton and hyperactivates Wnt signalling thus initiating mucinous colorectal cancer. Our study reveals the unexpected roles of an actin cytoskeletal regulator in maintaining epithelial cell integrity and suppressing tumorigenesis.
Asunto(s)
Adenocarcinoma Mucinoso/genética , Oxidorreductasas de Alcohol/genética , Neoplasias Colorrectales/genética , Citoesqueleto/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas de Microfilamentos/genética , beta Catenina/metabolismo , Adenocarcinoma Mucinoso/metabolismo , Adenocarcinoma Mucinoso/patología , Adenoma/genética , Adenoma/metabolismo , Adenoma/patología , Oxidorreductasas de Alcohol/metabolismo , Animales , Línea Celular Tumoral , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Células HCT116 , Células HEK293 , Células HT29 , Humanos , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Desnudos , Proteínas de Microfilamentos/metabolismo , Unión ProteicaRESUMEN
Vesicular acidification and trafficking are associated with various cellular processes. However, their pathologic relevance to cancer remains elusive. We identified transmembrane protein 9 (TMEM9) as a vesicular acidification regulator. TMEM9 is highly upregulated in colorectal cancer. Proteomic and biochemical analyses show that TMEM9 binds to and facilitates assembly of vacuolar-ATPase (v-ATPase), a vacuolar proton pump, resulting in enhanced vesicular acidification and trafficking. TMEM9-v-ATPase hyperactivates Wnt/ß-catenin signalling via lysosomal degradation of adenomatous polyposis coli (APC). Moreover, TMEM9 transactivated by ß-catenin functions as a positive feedback regulator of Wnt signalling in colorectal cancer. Genetic ablation of TMEM9 inhibits colorectal cancer cell proliferation in vitro, ex vivo and in vivo mouse models. Moreover, administration of v-ATPase inhibitors suppresses intestinal tumorigenesis of APC mouse models and human patient-derived xenografts. Our results reveal the unexpected roles of TMEM9-controlled vesicular acidification in hyperactivating Wnt/ß-catenin signalling through APC degradation, and propose the blockade of TMEM9-v-ATPase as a viable option for colorectal cancer treatment.
Asunto(s)
Transformación Celular Neoplásica/metabolismo , Proteínas de la Membrana/metabolismo , ATPasas de Translocación de Protón Vacuolares/metabolismo , Vía de Señalización Wnt , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Animales , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Células HCT116 , Células HT29 , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Intestinos/química , Intestinos/patología , Proteínas de la Membrana/genética , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Desnudos , Unión Proteica , Trasplante HeterólogoRESUMEN
Fine control of stem cell maintenance and activation is crucial for tissue homeostasis and regeneration. However, the mechanism of quiescence exit of Tert+ intestinal stem cells (ISCs) remains unknown. Employing a Tert knockin (TertTCE/+) mouse model, we found that Tert+ cells are long-term label-retaining self-renewing cells, which are partially distinguished from the previously identified +4 ISCs. Tert+ cells become mitotic upon irradiation (IR) injury. Conditional ablation of Tert+ cells impairs IR-induced intestinal regeneration but not intestinal homeostasis. Upon IR injury, Wnt signaling is specifically activated in Tert+ cells via the ROS-HIFs-transactivated Wnt2b signaling axis. Importantly, conditional knockout of ß-catenin/Ctnnb1 in Tert+ cells undermines IR-induced quiescence exit of Tert+ cells, which subsequently impedes intestinal regeneration. Our results that Wnt-signaling-induced activation of Tert+ ISCs is indispensable for intestinal regeneration unveil the underlying mechanism for how Tert+ stem cells undergo quiescence exit upon tissue injury.
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Mucosa Intestinal/metabolismo , Telomerasa/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Animales , Mucosa Intestinal/citología , Intestinos/fisiología , Ratones , Ratones Noqueados , Ratones Mutantes , Regeneración/genética , Regeneración/fisiología , Células Madre/citología , Células Madre/metabolismo , Telomerasa/genética , Vía de Señalización Wnt/genética , Vía de Señalización Wnt/fisiologíaRESUMEN
Despite the implication of Wnt signalling in radioresistance, the underlying mechanisms are unknown. Here we find that high Wnt signalling is associated with radioresistance in colorectal cancer (CRC) cells and intestinal stem cells (ISCs). We find that LIG4, a DNA ligase in DNA double-strand break repair, is a direct target of ß-catenin. Wnt signalling enhances non-homologous end-joining repair in CRC, which is mediated by LIG4 transactivated by ß-catenin. During radiation-induced intestinal regeneration, LIG4 mainly expressed in the crypts is conditionally upregulated in ISCs, accompanied by Wnt/ß-catenin signalling activation. Importantly, among the DNA repair genes, LIG4 is highly upregulated in human CRC cells, in correlation with ß-catenin hyperactivation. Furthermore, blocking LIG4 sensitizes CRC cells to radiation. Our results reveal the molecular mechanism of Wnt signalling-induced radioresistance in CRC and ISCs, and further unveils the unexpected convergence between Wnt signalling and DNA repair pathways in tumorigenesis and tissue regeneration.
Asunto(s)
Proliferación Celular/efectos de la radiación , Neoplasias Colorrectales/genética , Reparación del ADN por Unión de Extremidades/genética , ADN Ligasas/genética , Regulación Neoplásica de la Expresión Génica , Intestinos/efectos de la radiación , Tolerancia a Radiación/genética , Células Madre/efectos de la radiación , Animales , Animales Modificados Genéticamente , Línea Celular Tumoral , Proliferación Celular/genética , Supervivencia Celular/genética , Supervivencia Celular/efectos de la radiación , Simulación por Computador , Roturas del ADN de Doble Cadena , ADN Ligasa (ATP) , Reparación del ADN/genética , Perfilación de la Expresión Génica , Humanos , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Intestinos/citología , Ratones , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/metabolismo , Telomerasa/genética , Activación Transcripcional , Vía de Señalización Wnt/genética , beta Catenina/metabolismoRESUMEN
Cancer stem cells (CSCs) contribute to tumour heterogeneity, therapy resistance and metastasis. However, the regulatory mechanisms of cancer cell stemness remain elusive. Here we identify PCNA-associated factor (PAF) as a key molecule that controls cancer cell stemness. PAF is highly expressed in breast cancer cells but not in mammary epithelial cells (MECs). In MECs, ectopic expression of PAF induces anchorage-independent cell growth and breast CSC marker expression. In mouse models, conditional PAF expression induces mammary ductal hyperplasia. Moreover, PAF expression endows MECs with a self-renewing capacity and cell heterogeneity generation via Wnt signalling. Conversely, ablation of endogenous PAF induces the loss of breast cancer cell stemness. Further cancer drug repurposing approaches reveal that NVP-AUY922 downregulates PAF and decreases breast cancer cell stemness. Our results unveil an unsuspected role of the PAF-Wnt signalling axis in modulating cell plasticity, which is required for the maintenance of breast cancer cell stemness.
Asunto(s)
Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Carcinoma Lobular/metabolismo , Proteínas Portadoras/metabolismo , Plasticidad de la Célula/fisiología , Regulación Neoplásica de la Expresión Génica , Glándulas Mamarias Animales/metabolismo , Células Madre Neoplásicas/metabolismo , Vía de Señalización Wnt , Animales , Animales Modificados Genéticamente , Antineoplásicos/farmacología , Proteínas Portadoras/genética , Línea Celular Tumoral , Plasticidad de la Célula/efectos de los fármacos , Proteínas de Unión al ADN , Femenino , Perfilación de la Expresión Génica , Células HEK293 , Humanos , Hiperplasia , Immunoblotting , Isoxazoles/farmacología , Estimación de Kaplan-Meier , Células MCF-7 , Glándulas Mamarias Animales/patología , Ratones , Células Madre Neoplásicas/efectos de los fármacos , Resorcinoles/farmacología , Ensayo de Tumor de Célula MadreRESUMEN
Stress has been suggested as one of important cause of human cancer without molecular biological evidence. Thus, we test the effect of stress-related hormones on cell viability and mitotic fidelity. Similarly to estrogen, stress hormone cortisol and its relative cortisone increase microtubule organizing center (MTOC) number through elevated expression of γ-tubulin and provide the Taxol resistance to human cancer cell lines. However, these effects are achieved by glucocorticoid hormone receptor (GR) but not by estrogen receptor (ER). Since ginsenosides possess steroid-like structure, we hypothesized that it would block the stress or estrogen-induced MTOC amplification and Taxol resistance. Among tested chemicals, rare ginsenoside, CSH1 (Rg6) shows obvious effect on inhibition of MTOC amplification, γ-tubulin induction and Taxol resistance. Comparing to Fulvestant (FST), ER-α specific inhibitor, this chemical can block the cortisol/cortisone-induced MTOC deregulation as well as ER-α signaling. Our results suggest that stress hormone induced tumorigenesis would be achieved by MTOC amplification, and CSH1 would be useful for prevention of stress-hormone or steroid hormone-induced chromosomal instability.