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The 2021 World Health Organization (WHO) classification of the central nervous system (CNS) tumors has classified diffuse leptomeningeal glioneuronal tumor (DLGNT) as a mixed neuronal and glial tumor. Here, we report a DLGNT with two distinct morphological tumor components but identical molecular features. A four-year-old female child presented with progressive right upper extremity weakness. Magnetic resonance imaging (MRI) revealed the leptomeningeal enhancement over the brain stem and cervicothoracic spine. The histological examination of surgical specimens revealed two distinct tumor components: approximately half of the tumor is composed of oligodendroglioma-like tumor intermingled with nodules of ganglioglioma-like tumor. Immunohistochemistry confirmed the oligodendroglioma and ganglioglioma features. The molecular genetic studies demonstrated the features of DLGNT, including fusion of KIAA1549::BRAF, deletion of chromosome 1p, and absence of isocitrate dehydrogenase 1/2 (IDH1/2) mutation in both tumor components. Interestingly, the genetic studies also revealed the distinct chromosomal abnormalities of the loss of chromosome 4 only in oligodendroglioma-like tumor and copy neutral loss of heterozygosity of 7Q34Q36.3 in the ganglioglioma-like tumor component. This case highlights the critical role of molecular testing in the diagnosis of rare cases of DLGNT with diverse morphological components as well as in the identification of unique molecular alternations responsible for morphological phenotypes of the distinct tumors in DLGNT.
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Small molecule degraders of small ubiquitin-related modifier 1 (SUMO1) induce SUMO1 degradation in colon cancer cells and inhibits the cancer cell growth; however, it is unclear how SUMO1 degradation leads to the anticancer activity of the degraders. Genome-wide CRISPR-Cas9 knockout screen has identified StAR-related lipid transfer domain containing 7 (StarD7) as a critical gene for the degrader's anticancer activity. Here, we show that both StarD7 mRNA and protein are overexpressed in human colon cancer and its knockout significantly reduces colon cancer cell growth and xenograft progression. The treatment with the SUMO1 degrader lead compound HB007 reduces StarD7 mRNA and protein levels and increases endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production in colon cancer cells and three-dimensional (3D) organoids. The study further provides a novel mechanism of the compound anticancer activity that SUMO1 degrader-induced decrease of StarD7 occur through degradation of SUMO1, deSUMOylation and degradation of T cell-specific transcription 4 (TCF4) and thereby inhibition of its transcription of StarD7 in colon cancer cells, 3D organoids and patient-derived xenografts (PDX).
Assuntos
Proteínas de Transporte , Neoplasias do Colo , Humanos , Proteínas de Transporte/genética , Espécies Reativas de Oxigênio/metabolismo , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , RNA Mensageiro , Estresse do Retículo Endoplasmático , Proteína SUMO-1/genética , Proteína SUMO-1/metabolismo , Fator de Transcrição 4/metabolismoRESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) remains one of the most lethal cancers globally. Despite advancements in immunotherapy, the prognosis for patients with HCC continues to be poor. As oxidative stress plays a significant role in the onset and progression of various diseases, including metabolism-related HCC, comprehending its mechanism in HCC is critical for effective diagnosis and treatment. METHODS: This study utilized the TCGA dataset and a collection of oxidative stress genes to determine the expression of oxidative stress-related genes in HCC and their association with overall survival using diverse bioinformatics methods. A novel prognostic risk model was developed, and the TCGA cohort was divided into high-risk and low-risk groups based on each tumor sample's risk score. Levels of immune cell infiltration and the expression of immune checkpoint-related genes in different risk subgroups were analyzed to investigate the potential link between tumor immunity and oxidative stress-related features. The expression of model genes in actual samples was validated through immunohistochemistry, and their mRNA and protein expression levels were measured in cell cultures. RESULTS: Four oxidative stress-related genes (EZH2, ANKZF1, G6PD, and HMOX1) were identified and utilized to create a predictive risk model for HCC patient overall survival, which was subsequently validated in an independent cohort. A significant correlation was found between the expression of these prognostic genes and the infiltration of tumor immune cells. Elevated expression of EZH2, ANKZF1, G6PD, and HMOX1 was observed in both HCC tissues and cell lines. CONCLUSION: The combined assessment of EZH2, ANKZF1, G6PD, and HMOX1 gene expression can serve as a model to evaluate the risk of oxidative stress in HCC. Furthermore, there is a notable correlation between the expression of these risk model genes and tumor immunity.
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BACKGROUND: There is growing evidence indicating the insulin-like growth factor 1 receptor (IGF-1R) plays a critical role in the progression of human colorectal carcinomas. IGF-1R is an attractive drug target for the treatment of colon cancer. Picropodophyllin (PPP), of the cyclolignan family, has recently been identified as an IGF-1R inhibitor. The aim of this study is to determine the therapeutic response and mechanism after colorectal carcinoma treatment with PPP. METHODS: Seven colorectal carcinoma cell lines were treated with PPP. Following treatment, cells were analyzed for growth by a cell viability assay, sub-G1 apoptosis by flow cytometry, caspase cleavage and activation of AKT and extracellular signal-regulated kinase (ERK) by western blot analysis. To examine the in vivo therapeutic efficacy of PPP, mice implanted with human colorectal carcinoma xenografts underwent PPP treatment. RESULTS: PPP treatment blocked the phosphorylation of IGF-1R, AKT and ERK and inhibited the growth of TP53 wild-type but not mutated colorectal carcinoma cell lines. The treatment of PPP also induced apoptosis in TP53 wild-type cells as evident by the presence of sub-G1 cells and the cleavage of caspase-9, caspase-3, DNA fragmentation factor-45 (DFF45), poly (ADP-ribose) polymerase (PARP), and X-linked inhibitor of apoptosis protein (XIAP). The loss of BAD phosphorylation in the PPP-treated TP53 wild type cells further suggested that the treatment induced apoptosis through the BAD-mediated mitochondrial pathway. In contrast, PPP treatment failed to induce the phosphorylation of AKT and ERK and caspase cleavage in TP53 mutated colorectal carcinoma cell lines. Finally, PPP treatment suppressed the growth of xenografts derived from TP53 wild type but not mutated colorectal carcinoma cells. CONCLUSIONS: We report the association of TP53 mutations with the resistance of treatment of colorectal carcinoma cells in culture and in a xenograft mouse model with the IGF-1R inhibitor PPP. TP53 mutations often occur in colorectal carcinomas and could be used as a biomarker to predict the resistance of colorectal carcinomas to the treatment by this IGF-1R inhibitor.
Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Mutação , Podofilotoxina/análogos & derivados , Receptor IGF Tipo 1/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Camundongos , Fosforilação/efeitos dos fármacos , Podofilotoxina/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor IGF Tipo 1/metabolismo , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Oxidative stress (OS) is a condition in which the body has an unbalanced oxidative and antioxidant effect. Oxidative stress has emerged as a critical component in the onset and progression of numerous diseases, including liver cancer and chronic liver disease caused by the hepatitis C virus and hepatitis B virus. Reactive oxygen species (ROS) are the most prevalent reactive chemical species involved in the oxidative stress response during the progression of the disease. Oxidative stress has a unique role in the development of hepatocellular carcinoma (HCC), and excessive ROS production is a common occurrence in liver illnesses of various etiologies. In response to various deleterious stimuli, the liver shows manifestations of lipid accumulation, oxidative damage, inflammatory infiltration, and immune response, which interact with each other in a mutually reinforcing manner, collectively exacerbating liver damage and malignant transformation. The intracellular buildup of ROS is a two-edged sword for tumor advancement. ROS are tumorigenic, and low amounts of ROS can trigger different signaling pathways that promote proliferation, survival, and migration, among other aspects. However, excessive oxidative stress can induce tumor cell death. Understanding the mechanisms of oxidative stress in hepatocellular carcinogenesis is beneficial for the prevention and surveillance of hepatocellular carcinoma in humans. An improved knowledge of the impacts and potential implications of oxidative stress regulation in therapeutic strategies will likely allow us to find new therapeutic targets for cancer. Oxidative stress also plays a significant role in the treatment of hepatocellular carcinoma and the mechanisms of drug resistance involved. This paper reviews recent studies on oxidative stress in HCC that are more reliable and important, and provides a more comprehensive view of the development of the treatment of HCC based on the relevant summaries of the effect of oxidative stress on the treatment.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo , CarcinogêneseRESUMO
Phosphoinositide 3-kinase enhancer (PIKE) binds and enhances phosphatidylinositol 3-kinase (PI3K)/Akt activities. However, its physiological functions in brain have never been explored. Here we show that PIKE is important in regulating the neuronal survival and development of neocortex. During development, enhanced apoptosis is observed in the ventricular zone of PIKE knock-out (PIKE(-/-)) cortex. Moreover, PIKE(-/-) neurons show reduced dendritic complexity, dendritic branch length, and soma size. These defects are due to the reduced PI3K/Akt activities in PIKE(-/-) neurons, as the impaired dendritic arborization can be rescued when PI3K/Akt cascade is augmented in vitro or in PIKE(-/-)PTEN(-/-) double-knock-out mice. Interestingly, PIKE(-/-) mice display behavioral abnormality in locomotion and spatial navigation. Because of the diminished PI3K/Akt activities, PIKE(-/-) neurons are more vulnerable to glutamate- or stroke-induced neuronal cell death. Together, our data established the critical role of PIKE in regulating neuronal survival and development by substantiating the PI3K/Akt pathway.
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Sobrevivência Celular/fisiologia , Dendritos/fisiologia , GTP Fosfo-Hidrolases/fisiologia , Neocórtex/crescimento & desenvolvimento , Neocórtex/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Neurogênese/fisiologia , Neurônios/fisiologia , Animais , Apoptose/genética , Apoptose/fisiologia , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Fator Neurotrófico Derivado do Encéfalo/fisiologia , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Dendritos/metabolismo , Dendritos/ultraestrutura , GTP Fosfo-Hidrolases/genética , Ácido Glutâmico/farmacologia , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/fisiopatologia , Locomoção/genética , Locomoção/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neocórtex/citologia , Neocórtex/metabolismo , Proteínas do Tecido Nervoso/genética , Neurogênese/genética , Neurônios/metabolismo , Neurônios/ultraestrutura , Tamanho do Órgão , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Comportamento Espacial/fisiologiaRESUMO
A20 was initially identified as a primary gene product following TNF α treatment in human umbilical vein endothelial cells. Increased A20 expression is associated with tumorigenesis in many cancers, whereas the loss of A20 function is linked to lymphoma. It has been reported that A20 protects cells from TRAIL-induced apoptosis; however, the mechanism by which A20 is involved is still largely unknown. Our results indicate that TRAIL induces the hepatocellular carcinoma apoptosis associated with A20 knockdown in a concentration-dependent manner. TRAIL-induced apoptosis requires p18 caspase-8 activation, and, the activation of caspase-8 is at least in part, due to the direct cleavage of RIP1 by A20 knockdown. These findings suggest that A20 modulates the sensitivity to TRAIL by RIP1 ubiquitination, thereby repressing the recruitment and activation of pro-caspase-8 into the active form caspase-8. Thus, our study suggests that A20 protects against TRAIL-induced apoptosis through the regulation of RIP1 ubiquitination.
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Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinoma Hepatocelular/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Hepáticas/metabolismo , Proteínas Nucleares/genética , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Caspase 8/metabolismo , Proteínas de Ligação a DNA , Técnicas de Silenciamento de Genes , Marcação de Genes , Células Hep G2 , Humanos , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , UbiquitinaçãoRESUMO
Asparaginyl endopeptidase (AEP or legumain) is a lysosomal cysteine protease that cleaves protein substrates on the C-terminal side of asparagine. AEP plays a pivotal role in the endosome/lysosomal degradation system and is implicated in antigen processing. The processing of the lysosomal proteases cathepsins in kidney is completely defective in AEP-deficient mice with accumulation of macromolecules in the lysosomes, which is typically seen in lysosomal disorders. Here we show that mutant mice lacking AEP develop fever, cytopenia, hepatosplenomegaly, and hemophagocytosis, which are primary pathological manifestations of hemophagocytic syndrome/hemophagocytic lymphohistiocytosis (HLH). Moreover, AEP deficiency provokes extramedullary hematopoiesis in the spleen and abnormally enlarged histiocytes with ingested red blood cells (RBCs) in bone marrow. Interestingly, RBCs from AEP-null mice are defective in plasma membrane components. Further, AEP-null mice display lower natural killer cell activity, but none of the major cytokines is substantially abnormal. These results indicate that AEP might be a previously unrecognized component in HLH pathophysiology.
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Cisteína Endopeptidases/deficiência , Linfo-Histiocitose Hemofagocítica/etiologia , Animais , Medula Óssea/patologia , Hematopoese Extramedular , Células Matadoras Naturais , Linfo-Histiocitose Hemofagocítica/enzimologia , Linfo-Histiocitose Hemofagocítica/patologia , Camundongos , Camundongos Knockout , Pancitopenia , Baço/patologia , EsplenomegaliaRESUMO
Recent studies suggest that cancer stem cells (CSCs) are responsible for cancer resistance to therapies. We therefore investigated how glioblastoma-derived CSCs respond to the treatment of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Neurospheres were generated from glioblastomas, characterized for CSC properties including self-renewal, cell differentiation and xenograft formation capacity, and analyzed for TRAIL-induced apoptosis, CASP8 genomic status, and caspase-8 protein expression. The neurosphere NSC326 was sensitive to TRAIL-induced apoptosis as evidenced by cell death and caspase-8, -3, and -7 enzymatic activities. In contrast, however, the neurosphere NSC189 was TRAIL-resistant. G-banding analysis identified five chromosomally distinguishable cell populations in the neurospheres. Fluorescence in situ hybridization revealed the variation of chromosome 2 copy number in these populations and the loss of CASP8 locus in 2q33-34 region in a small set of cell populations in the neurosphere. Immunohistochemistry of NSC189 cell blocks revealed the lack of caspase-8 protein in a subset of neurosphere cells. Western blotting and immunohistochemistry of human glioblastoma tumors demonstrated the expression of caspase-8 protein in the vast majority of the tumors as compared to normal human brain tissues that lack the caspase-8 expression. This study shows heterogeneity of glioblastomas and derived CSCs in the genomic status of CASP8, expression of caspase-8, and thus responsiveness to TRAIL-induced apoptosis. Clinic trials may consider genomic analysis of the cancer tissue to identify the genomic loss of CASP8 and use it as a genomic marker to predict the resistance of glioblastomas to TRAIL apoptosis pathway-targeted therapies.
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Caspase 8/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Heterogeneidade Genética , Glioblastoma/metabolismo , Transdução de Sinais , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/metabolismo , Caspase 8/genética , Diferenciação Celular/efeitos dos fármacos , Cromossomos Humanos Par 2/química , Cromossomos Humanos Par 2/genética , Feminino , Loci Gênicos , Marcadores Genéticos , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Imuno-Histoquímica , Camundongos , Camundongos SCID , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Cultura Primária de Células , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transplante HeterólogoRESUMO
Glioblastoma-derived stem cells (GSCs) are responsible for the cancer resistance to therapies. We show here that GSC-enriched neurospheres are resistant to the treatment of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) due to the insufficient expression of the death receptor DR4 and DR5 and the overexpression of cellular Fas-associated death domain-like interleukin-1ß-converting enzyme-inhibitory protein (c-FLIP). However, treatment with cisplatin leads to the upregulation of DR5 and downregulation of c-FLIP and restores TRAIL apoptotic pathway in the neurospheres. This study suggests that the combined treatment of TRAIL and cisplatin can induce apoptosis in GSCs and thus provide an effective treatment of glioblastomas.
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Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/fisiologia , Cisplatino/farmacologia , Glioblastoma/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/fisiologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Animais , Linhagem Celular Tumoral , Feminino , Glioblastoma/patologia , Humanos , Camundongos , Regulação para Cima/efeitos dos fármacosRESUMO
Glioblastomas (GBMs) are highly aggressive, recurrent, and lethal brain tumors that are maintained via brain tumor-initiating cells (BTICs). The aggressiveness of BTICs may be dependent on the extracellular matrix (ECM) molecules that are highly enriched within the GBM microenvironment. Here, we investigated the expression of ECM molecules in GBM patients by mining the transcriptomic databases and also staining human GBM specimens. RNA levels for fibronectin, brevican, versican, heparan sulfate proteoglycan 2 (HSPG2), and several laminins were high in GBMs compared to normal brain, and this was corroborated by immunohistochemistry. While fibrinogen transcript was at normal level in GBM, its protein immunoreactivity was prominent within GBM tissues. These ECM molecules in tumor specimens were in proximity to, and surrounding BTICs. In culture, fibronectin and pan-laminin induced the adhesion of BTICs onto the plastic substratum. However, fibrinogen increased the size of the BTIC spheres by facilitating the adhesive property, motility, and invasiveness of BTICs. These features of elevated invasiveness were corroborated in resected GBM specimens by the close proximity of fibrinogen with matrix metalloproteinase (MMP)-2 and-9, which are proteases implicated in metastasis. Moreover, the effect of fibrinogen-induced invasiveness was attenuated in BTICs where MMP-2 and -9 have been inhibited with siRNAs or pharmacological inhibitors. Our results implicate fibrinogen in GBM as a mediator of the invasive properties of BTICs, and as a target for therapy to reduce BTIC tumorigenecity.
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Neoplasias Encefálicas/patologia , Fibrinogênio/metabolismo , Glioblastoma/patologia , Células-Tronco Neoplásicas/patologia , Microambiente Tumoral/genética , Encéfalo/patologia , Neoplasias Encefálicas/genética , Regulação Neoplásica da Expressão Gênica/genética , Glioblastoma/genética , Humanos , Células-Tronco Neoplásicas/metabolismo , Microambiente Tumoral/fisiologiaRESUMO
Despite the connection of secretory cells, including goblet and enteroendocrine (EEC) cells, to distinct mucus-containing colorectal cancer histologic subtypes, their role in colorectal cancer progression has been underexplored. Here, our analysis of The Cancer Genome Atlas (TCGA) and single-cell RNA-sequencing data demonstrates that EEC progenitor cells are enriched in BRAF-mutant colorectal cancer patient tumors, cell lines, and patient-derived organoids. In BRAF-mutant colorectal cancer, EEC progenitors were blocked from differentiating further by DNA methylation and silencing of NEUROD1, a key gene required for differentiation of intermediate EECs. Mechanistically, secretory cells and the factors they secrete, such as trefoil factor 3, promoted colony formation and activation of cell survival pathways in the entire cell population. Lysine-specific demethylase 1 (LSD1) was identified as a critical regulator of secretory cell specification in vitro and in a colon orthotopic xenograft model, where LSD1 loss blocks formation of EEC progenitors and reduces tumor growth and metastasis. These findings reveal an important role for EEC progenitors in supporting colorectal cancer. SIGNIFICANCE: This study establishes enteroendocrine progenitors as a targetable population that promotes BRAF-mutant colorectal cancer and can be blocked by LSD1 inhibition to suppress tumor growth.
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Neoplasias Colorretais/genética , Metilação de DNA , Células Enteroendócrinas/metabolismo , Histona Desmetilases/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Animais , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Células Enteroendócrinas/patologia , Células HT29 , Xenoenxertos , Histona Desmetilases/deficiência , Histona Desmetilases/genética , Humanos , Camundongos , Proteínas Proto-Oncogênicas B-raf/metabolismo , Células-Tronco/metabolismo , Células-Tronco/patologiaRESUMO
Brain tumorinitiating cells (BTICs) drive glioblastoma growth through not fully understood mechanisms. Here, we found that about 8% of cells within the human glioblastoma microenvironment coexpress programmed cell death 1 (PD-1) and BTIC marker. Gain- or loss-of-function studies revealed that tumor-intrinsic PD-1 promoted proliferation and self-renewal of BTICs. Phosphorylation of tyrosines within the cytoplasmic tail of PD-1 recruited Src homology 2containing phosphatase 2 and activated the nuclear factor kB in BTICs. Notably, the tumor-intrinsic promoting effects of PD-1 did not require programmed cell death ligand 1(PD-L1) ligation; thus, the therapeutic antibodies inhibiting PD-1/PD-L1 interaction could not overcome the growth advantage of PD-1 in BTICs. Last, BTIC-intrinsic PD-1 accelerated intracranial tumor growth, and this occurred in mice lacking T and B cells. These findings point to a critical role for PD-1 in BTICs and uncover a nonimmune resistance mechanism of patients with glioblastoma to PD-1 or PD-L1blocking therapies.
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Discovery of small-molecule degraders that activate ubiquitin ligasemediated ubiquitination and degradation of targeted oncoproteins in cancer cells has been an elusive therapeutic strategy. Here, we report a cancer cellbased drug screen of the NCI drug-like compounds library that enabled identification of small-molecule degraders of the small ubiquitin-related modifier 1 (SUMO1). Structure-activity relationship studies of analogs of the hit compound CPD1 led to identification of a lead compound HB007 with improved properties and anticancer potency in vitro and in vivo. A genome-scale CRISPR-Cas9 knockout screen identified the substrate receptor F-box protein 42 (FBXO42) of cullin 1 (CUL1) E3 ubiquitin ligase as required for HB007 activity. Using HB007 pull-down proteomics assays, we pinpointed HB007's binding protein as the cytoplasmic activation/proliferation-associated protein 1 (CAPRIN1). Biolayer interferometry and compound competitive immunoblot assays confirmed the selectivity of HB007's binding to CAPRIN1. When bound to CAPRIN1, HB007 induced the interaction of CAPRIN1 with FBXO42. FBXO42 then recruited SUMO1 to the CAPRIN1-CUL1-FBXO42 ubiquitin ligase complex, where SUMO1 was ubiquitinated in several of human cancer cells. HB007 selectively degraded SUMO1 in patient tumorderived xenografts implanted into mice. Systemic administration of HB007 inhibited the progression of patient-derived brain, breast, colon, and lung cancers in mice and increased survival of the animals. This cancer cellbased screening approach enabled discovery of a small-molecule degrader of SUMO1 and may be useful for identifying other small-molecule degraders of oncoproteins.
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Neoplasias , Proteína SUMO-1 , Animais , Humanos , Camundongos , Neoplasias/tratamento farmacológico , Proteína SUMO-1/genética , Proteína SUMO-1/metabolismo , UbiquitinaçãoRESUMO
To explore the molecular mechanisms by which glioblastomas are resistant to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), we examined TRAIL signalling pathways in the tumours. TRAIL has four membrane-anchored receptors, death receptor 4/5 (DR4/5) and decoy receptor 1/2 (DcR1/2). Of these receptors, only DR5 was expressed consistently in glioblastoma cell lines and tumour tissues, ruling out the role of DcR1/2 in TRAIL resistance. Upon TRAIL binding, DR5 was homotrimerized and recruited Fas-associated death domain (FADD) and caspase-8 for the assembly of death-inducing signalling complex (DISC) in the lipid rafts of the plasma membrane. In the DISC, caspase-8 was cleaved and initiated apoptosis by cleaving downstream caspases in TRAIL-sensitive glioblastoma cells. In TRAIL-resistant cells, however, DR5-mediated DISC was modified by receptor-interacting protein (RIP), cellular FADD-like interleukin-1beta-converting enzyme inhibitory protein (c-FLIP) and phosphoprotein enriched in diabetes or in astrocyte-15 (PED/PEA-15). This DISC modification occurred in the non-raft fractions of the plasma membrane and resulted in the inhibition of caspase-8 cleavage and activation of nuclear factor-kappaB (NF-kappaB). Treatment of resistant cells with parthenolide, an inhibitor of inhibitor of kappaB (I-kappaB), eliminated TRAIL-induced NF-kappaB activity but not TRAIL resistance. In contrast, however, targeting of RIP, c-FLIP or PED/PEA-15 with small interfering RNA (siRNA) led to the redistribution of the DISC from non-rafts to lipid rafts and eliminated the inhibition of caspase-8 cleavage and thereby TRAIL resistance. Taken together, this study indicates that the DISC modification by RIP, c-FLIP and PED/PEA-15 is the most upstream event in TRAIL resistance in glioblastomas.
Assuntos
Apoptose , Caspase 8/metabolismo , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/metabolismo , Glioblastoma/enzimologia , Glioblastoma/patologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Microdomínios da Membrana/efeitos dos fármacos , Microdomínios da Membrana/metabolismo , NF-kappa B/metabolismo , Fosfoproteínas/metabolismo , Transporte Proteico/efeitos dos fármacos , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologiaRESUMO
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is currently under clinical development as a cancer therapeutic because it can induce apoptosis selectively in cancer cells. The vast majority of hepatocellular carcinomas (HCC), however, are resistant to TRAIL. In search of cancer therapeutics that can overcome TRAIL resistance, we show here that celecoxib and camptothecin can sensitize TRAIL-resistant HCC cell lines, HepG2 and Hep3B, to TRAIL-induced apoptosis through downregulation of cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP) and cleavage of caspase-8 and caspase-3 in the HCC cells. The study suggests a framework for TRAIL-based combination treatment of HCC.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Antineoplásicos Fitogênicos/farmacologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Camptotecina/farmacologia , Carcinoma Hepatocelular/enzimologia , Caspase 3/metabolismo , Caspase 8/metabolismo , Celecoxib , Cisplatino/farmacologia , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Células Hep G2 , Humanos , Neoplasias Hepáticas/enzimologia , Pirazóis/farmacologia , Proteínas Recombinantes/farmacologia , Sulfonamidas/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologiaRESUMO
Adefovir dipivoxil treatment has significantly improved the outcome of chronic hepatitis B virus (HBV) infection. However, it remains largely unknown how immune system responds to the treatment. Chronic HBV patients were treated with adefovir dipivoxil and examined for serum HBV DNA loads, cytokines, and T helper (Th1) and 2 (Th2) cytokine producing T cells during 104 weeks of the treatment. Th1/Th2 cytokines producing T cells were significantly lower in chronic HBV patients as compared to normal individuals. Adefovir dipivoxil treatment led to the increase of Th1/Th2 cytokines producing T cells and serum cytokine levels in association with the decline of HVB DNA load. In contrast, Th1/Th2 cytokines producing T cells remained lower in one patient detected with adefovir dipivoxil resistant HBV A181T/V mutation. This study has established inverse correlation of the increase of Th1/Th2 immunity and the decline of HBV DNA load in chronic HBV patients during adefovir dipivoxil treatment.
Assuntos
Adenina/análogos & derivados , Antivirais/uso terapêutico , Citocinas , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/imunologia , Organofosfonatos/uso terapêutico , Células Th1/imunologia , Células Th2/imunologia , Adenina/uso terapêutico , Adulto , Ensaios Clínicos como Assunto , Citocinas/sangue , Citocinas/imunologia , DNA Viral/sangue , Feminino , Vírus da Hepatite B/genética , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/sangue , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is capable of inducing apoptosis in non-small cell lung carcinoma (NSCLC). However, many of the human NSCLC cell lines are resistant to TRAIL, and TRAIL treatment of the resistant cells leads to the activation of nuclear factor-kappaB (NF-kappaB) and extracellular signal-regulated kinase 1/2 (ERK1/2). TRAIL can induce apoptosis in TRAIL-sensitive NSCLC cells through the induction of death-inducing signaling complex (DISC) assembly in lipid rafts of plasma membrane. In the DISC, caspase-8 is cleaved and initiates TRAIL-induced apoptosis. In contrast, TRAIL-DISC assembly in the nonraft phase of the plasma membrane leads to the inhibition of caspase-8 cleavage and NF-kappaB and ERK1/2 activation in TRAIL-resistant NSCLC cells. Receptor-interacting protein (RIP) and cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP) mediates the DISC assembly in nonrafts and selective knockdown of either RIP or c-FLIP with interfering RNA redistributes the DISC from nonrafts to lipid rafts, thereby switching the DISC signals from NF-kappaB and ERK1/2 activation to caspase-8-initiated apoptosis. Chemotherapeutic agents inhibit c-FLIP expression, thereby enhancing the DISC assembly in lipid rafts for caspase-8-initiated apoptosis. These studies indicate that RIP and c-FLIP-mediated assembly of the DISC in nonrafts is a critical upstream event in TRAIL resistance and thus targeting of either RIP or c-FLIP may lead to the development of novel therapeutic strategies that can overcome TRAIL resistance in human NSCLC.
Assuntos
Apoptose , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Microdomínios da Membrana/química , Ligante Indutor de Apoptose Relacionado a TNF/fisiologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Colesterol/metabolismo , Humanos , Lipídeos/química , Neoplasias Pulmonares/metabolismo , Microdomínios da Membrana/metabolismo , NF-kappa B/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais , Ligante Indutor de Apoptose Relacionado a TNF/química , Fatores de TempoRESUMO
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has recently emerged as a cancer therapeutic agent because it is capable of preferentially inducing apoptosis in human cancer over normal cells. The majority of human pancreatic cancers, unfortunately, are resistant to TRAIL treatment. Here, we show that the inhibition of caspase-8 cleavage is the most upstream event in TRAIL resistance in pancreatic cancers. TRAIL treatment led to the cleavage of caspase-8 and downstream caspase-9, caspase-3, and DNA fragmentation factor 45 (DFF45) in TRAIL-sensitive pancreatic cancer cell lines (BXPC-3, PACA-2). This caspase-8-initiated caspase cascade, however, was inhibited in TRAIL-resistant pancreatic cancer cell lines (PANC-1, ASPC-1, CAPAN-1, CAPAN-2). The long and short forms of cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP(L), c-FLIP(S)) were highly expressed in the TRAIL-resistant as compared to the sensitive cells; knockdown of c-FLIP(L) and c-FLIP(S) by a short hairpin RNA (shRNA) rendered the resistant cells sensitive to TRAIL-induced apoptosis through the cleavage of caspase-8 and activation of the mitochondrial pathway. Receptor-interacting protein (RIP) has been reported in TRAIL-induced activation of NF-kappaB and we show here that knockdown of RIP sensitized the resistant cells to TRAIL-induced apoptosis. These results indicate the role of c-FLIP and RIP in caspase-8 inhibition and thus TRAIL resistance. Treatment of the resistant cells with camptothecin, celecoxib and cisplatin resulted in the downregulation of c-FLIP and caused a synergistic apoptotic effect with TRAIL. These studies therefore suggest that combination treatment with chemotherapy can overcome TRAIL resistance and enhance TRAIL therapeutic efficacy in treating pancreatic cancers.
Assuntos
Apoptose/efeitos dos fármacos , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/antagonistas & inibidores , Neoplasias Pancreáticas/patologia , Proteína Serina-Treonina Quinases de Interação com Receptores/antagonistas & inibidores , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Antineoplásicos/farmacologia , Caspase 8/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias Pancreáticas/enzimologia , Isoformas de Proteínas/metabolismoRESUMO
Human astrocytes express Fas yet are resistant to Fas-induced apoptosis. Here, we report that calcium/calmodulin-dependent protein kinase II (CaMKII) is constitutively activated in human astrocytes and protects the cells from apoptotic stimulation by Fas agonist. Once stimulated, Fas recruits Fas-associated death domain and caspase-8 for the assembly of the death-inducing signaling complex (DISC); however, caspase-8 cleavage is inhibited in the DISC. Inhibition of CaMKII kinase activity inhibits the expression of phosphoprotein enriched astrocytes-15 kDa/phosphoprotein enriched in diabetes (PEA-15/PED) and cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP), thus releasing their inhibition of caspase-8 cleavage. Inhibition of PEA-15/PED or c-FLIP by small interfering RNA sensitizes human astrocytes to Fas-induced apoptosis. In contrast, inhibition of CaMKII, PEA-15, or c-FLIP does not affect the sensitivity of human astrocytes to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL death receptors (DR4, DR5) are weakly expressed at mRNA, protein, and cell surface levels and thus fail to mediate the assembly of the DISC in human astrocytes. Overexpression of DR5 restores TRAIL signaling pathways and sensitizes the human astrocytes to TRAIL-induced apoptosis if CaMKII kinase activity or expression of PEA-15 and c-FLIP is inhibited; the results suggest that CaMKII-mediated pathways prevent TRAIL-induced apoptosis in human astrocytes under conditions in which TRAIL death receptors are upregulated. This study has therefore identified the molecular mechanisms that protect normal human astrocytes from apoptosis induced by Fas ligand and TRAIL.