RESUMO
BACKGROUND: The E3 ubiquitin ligase HECTD3 is a homologue of the E6-related protein carboxyl terminus, which plays a crucial role in biological processes and tumourigenesis. However, the functional characterisation of HECTD3 in glioblastoma is still elusive. METHODS: Determination of the functional role of HECTD3 in glioblastoma was made by a combination of HECTD3 molecular pattern analysis from human glioblastoma databases and subcutaneous and in situ injections of tumours in mice models. RESULTS: This study reports that the DOC domain of HECTD3 interacts with the DNA binding domain of PARP1, and HECTD3 mediated the K63-linked polyubiquitination of PARP1 and stabilised the latter expression. Moreover, the Cysteine (Cys) 823 (ubiquitin-binding site) mutation of HECTD3 significantly reduced PARP1 polyubiquitination and HECTD3 was involved in the recruitment of ubiquitin-related molecules to PARP1 ubiquitin-binding sites (Lysines 209 and 221, respectively). Lastly, activation of EGFR-mediated signalling pathways by HECTD3 regulates PARP1 polyubiquitination. CONCLUSION: Our results unveil the potential role of HECTD3 in glioblastoma and strongly preconise further investigation and consider HECTD3 as a promising therapeutic marker for glioblastoma treatment.
Assuntos
Glioblastoma , Humanos , Animais , Camundongos , Glioblastoma/genética , Ubiquitinação , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Carcinogênese/genética , Transformação Celular Neoplásica , Ubiquitinas/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismoRESUMO
RAN binding protein 10 (RANBP10), a ubiquitously expressed and evolutionarily conserved protein, as a RAN-GTP exchange factor (GEF) to regulate several factors involved in cellular progression. Previous studies showed that RANBP10 was overexpressed in prostate cancer cells and was responsible for androgen receptor (AR) activation. However, the biological function of RANBP10 in glioblastoma (GBM) has not been studied. Here, we found that RANBP10 was overexpressed in GBM, and high RANBP10 expression was closely linked to poor survival of patients with GBM. Downregulation of RANBP10 significantly inhibited cell proliferation, migration, invasion, and tumor growth of GBM cells. In addition, we revealed that RANBP10 could suppress the promoter activity of FBXW7, and thereby increase the protein stability of c-Myc in GBM cells. Silencing of FBXW7 in RANBP10-knockdown GBM cells could partly negate the effects induced by RANBP10 downregulation. Taken together, our findings established that RANBP10 significantly promoted GBM progression by control of the FBXW7-c-Myc axis, and suggest that RANBP10 may be a potential target in GBM.
Assuntos
Progressão da Doença , Proteína 7 com Repetições F-Box-WD/genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/patologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Transdução de Sinais , Adulto , Animais , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Proteína 7 com Repetições F-Box-WD/metabolismo , Feminino , Inativação Gênica , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Modelos Biológicos , Invasividade Neoplásica , Prognóstico , Estabilidade Proteica , Proteólise , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transcrição Gênica , Ensaio Tumoral de Célula-Tronco , UbiquitinaçãoRESUMO
Stomach adenocarcinoma (STAD) is a leading cause of cancer deaths, and the outcome of the patients remains dismal for the lack of effective biomarkers of early detection. Recent studies have elucidated the landscape of genomic alterations of gastric cancer and reveal some biomarkers of advanced-stage gastric cancer, however, information about early-stage biomarkers is limited. Here, we adopt Weighted Gene Co-expression Network Analysis (WGCNA) to screen potential biomarkers for early-stage STAD using RNA-Seq and clinical data from TCGA database. We find six gene clusters (or modules) are significantly correlated with the stage-I STADs. Among these, five hub genes, i.e., MS4A1, THBS2, VCAN, PDGFRB, and KCNA3 are identified and significantly de-regulated in the stage-I STADs compared with the normal stomach gland tissues, which suggests they can serve as potential early diagnostic biomarkers. Moreover, we show that high expression of VCAN and PDGFRB is associated with poor prognosis of STAD. VCAN encodes a large chondroitin sulfate proteoglycan that is the main component of the extracellular matrix, and PDGFRB encodes a cell surface tyrosine kinase receptor for members of the platelet-derived growth factor (PDGF) family. Consistently, Gene Ontology (GO) analysis of differentially expressed genes in the STADs indicates terms associated with extracellular matrix and receptor ligand activity are significantly enriched. Protein-protein network interaction analysis (PPI) and Gene Set Enrichment Analysis (GSEA) further support the core role of VCAN and PDGFRB in the tumorigenesis. Collectively, our study identifies the potential biomarkers for early detection and prognosis of STAD.