RESUMO
The tumor suppressor p53 is involved in variety of cell progresses including cell cycle arrest, apoptosis, DNA repair, senescence, cell metabolism and ferroptosis. Here, we identified lncRNA SCARNA10 (Small Cajal Body-Specific RNA 10) as a novel cellular factor that interacts with the DNA binding domain (DBD) of p53. Upon binding the DBD of p53 and CREB-binding protein (CBP), SCARNA10 promotes the acetylation of p53, and activates p53-mediated transcriptional activation. Overexpress or knockdown SCARNA10 leads to up (or down)-regulation of p53-mediated transcriptional activation, whereas not affecting p53 protein levels. Moreover, SCARNA10 directly activates transcription by increasing the acetylation of p53 C-terminal domain (CTD) without affecting p53 phosphorylation at Ser15. These results indicate that SCARNA10 is a novel factor which regulates p53 acetylation-dependent transcriptional activity and tumor suppression.
Assuntos
Processamento de Proteína Pós-Traducional , RNA , Proteína Supressora de Tumor p53 , Acetilação , Pontos de Checagem do Ciclo Celular , Ativação Transcricional , Proteína Supressora de Tumor p53/metabolismo , RNA/metabolismoRESUMO
BACKGROUND: Circulating long non-coding RNAs (lncRNAs) have been demonstrated to serve as diagnostic or prognosis biomarkers for various disease. We aimed to elucidate the diagnostic efficacy of serum lncRNA SCARNA10 for the hepatocellular carcinoma (HCC). METHODS: In this study, a total of 182 patients with HCC, 105 patients with benign liver disease (BLD), and 149 healthy controls (HC) were enrolled. According to different classifications, the levels of serum SCARNA10 were assessed by quantitative real-time polymerase chain reaction (qPCR). The correlations between serum SCARNA10 and clinicopathological characteristics were further analyzed. The receiver operating characteristic (ROC) curve and area under curve (AUC) were utilized to estimate the diagnostic capacity of serum SCARNA10 and its combination with AFP for HCC. RESULTS: The results demonstrated that the levels of serum SCARNA10 were significantly higher in HCC patients than in patients with BLD and healthy controls, and significantly increased in HCC patients with hepatitis B or C infection, or with liver cirrhosis. Furthermore, positive correlations were noted between serum SCARNA10 level and some clinicopathological characteristics, including tumor size, differentiation degrees, tumor stage, vascular invasion, tumor metastasis and complications. ROC analysis revealed that SCARNA10 had a significantly predictive value for HCC (Sensitivity = 0.70, Specificity = 0.77, and AUC = 0.82), the combination of SCARNA10 and AFP gained the higher sensitivity (AUCSCARNA10 + AFP = 0.92 vs AUCAFP = 0.83, p < 0.01). SCARNA10 retained significant diagnosis capabilities for AFP-negative HCC patients. CONCLUSIONS: In summary, lncRNA SCARNA10 may serve as a novel and non-invasive biomarker with relatively high sensitivity and specificity for HCC diagnosis.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Estudos de Casos e Controles , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , RNA Longo não Codificante/genética , Curva ROC , alfa-FetoproteínasRESUMO
Long non-coding RNAs (lncRNAs) are involved in numerous biological functions and pathological processes. However, the clinical significance of lncRNAs and their functions in liver fibrosis remain largely unclear. Methods: The transcript of lncRNA SCARNA10 in serum and liver samples from patients with advanced hepatic fibrosis, liver tissues from two fibrosis mouse models, and cultured hepatic stellate cells (HSCs) was determined by real-time RT-PCR. The effects of lentivirus-mediated knockdown or over-expression of SCARNA10 in liver fibrosis were examined in vitro and in vivo. Moreover, the effects and mechanisms of down-regulation or over-expression of SCARNA10 on the expression of the genes involved in TGFß pathway were determined. Results: It was found lncRNA ENSMUST00000158992, named as Scarna10, was remarkably up-regulated in mouse fibrotic livers according to the microarray data. We observed that the transcript of SCARNA10 was increased in the serum and liver from patients with advanced hepatic fibrosis. Furthermore, we found that SCARNA10 promoted liver fibrosis both in vitro and in vivo through inducing hepatocytes (HCs) apoptosis and HSCs activation. Mechanistically, RNA immunoprecipitation (RIP) assays demonstrated that SCARNA10 physically associated with polycomb repressive complex 2 (PRC2). Additionally, our results demonstrated that SCARNA10 functioned as a novel positive regulator of TGFß signaling in hepatic fibrogenesis by inhibiting the binding of PRC2 to the promoters of the genes associated with ECM and TGFß pathway, thus promoting the transcription of these genes. Conclusions: Our study identified a crucial role of SCARNA10 in liver fibrosis, providing a proof of this molecule as a potential diagnostic marker and a possible therapeutic target against liver fibrosis.