Hsa_circ_0007990 promotes breast cancer growth via inhibiting YBX1 protein degradation to activate E2F1 transcription.

Breast cancer (BC) is the most commonly diagnosed malignant tumour in females worldwide. Although remarkable advances in early detection and treatment strategies have led to decreased mortality, recurrence and metastasis remain the major causes of cancer death in BC patients. Increasing evidence has demonstrated that circular RNAs (circRNAs) play critical roles in cancer progression. However, the detailed biological functions and molecular mechanisms of circRNAs in BC are unclear. The aim of this study was to investigate the possible role of circRNAs in the progression of BC. Differentially expressed circRNAs in BC were identified by integrating breast tumour-associated somatic CNV data and circRNA high-throughput sequencing. Aberrant hsa_circ_0007990 expression and host gene copy number were detected in BC cell lines via quantitative polymerase chain reaction (qPCR). The expression level of hsa_circ_0007990 in BC tissues was validated by in situ hybridization (ISH). Loss- and gain-of-function experiments were performed in vitro and in vivo, respectively, to explore the potential biological function of hsa_circ_0007990 in BC. The underlying mechanisms of hsa_circ_0007990 were investigated through MS2 RNA pull-down, RNA immunoprecipitation, RNA fluorescence in situ hybridization, immunofluorescence, chromatin immunoprecipitation and luciferase reporter assays. The levels of hsa_circ_0007990 were elevated in BC tissues and cell lines, an effect that was partly due to host gene copy number gains. Functional assays showed that hsa_circ_0007990 promoted BC cell growth. Mechanistically, hsa_circ_0007990 could bind to YBX1 and inhibit its degradation by preventing ubiquitin/proteasome-dependent degradation, thus enhancing the expression of the cell cycle-associated gene E2F1. Rescue experiments suggested that hsa_circ_0007990 promoted BC progression through YBX1. In general, our study demonstrated that hsa_circ_0007990 modulates the ubiquitination and degradation of YBX1 protein and further regulates E2F1 expression to promote BC progression. We explored the possible function and molecular mechanism of hsa_circ_0007990 in BC and identified a novel candidate target for the treatment of BC.

Potential Targets and Mechanisms of Bitter Almond-Licorice for COVID-19 Treatment Based on Network Pharmacology and Molecular Docking.

BACKGROUND: The outbreak of Corona Virus Disease 2019 (COVID-19) has resulted in millions of infections and raised global attention. Bitter almonds and licorice are both Traditional Chinese Medicines (TCM), often used in combination to treat lung diseases. Several prescriptions in the guidelines for the diagnosis and treatment of coronavirus disease 2019 (trial version ninth) contained bitter almond-licorice, which was effective in the treatment of COVID-19. However, the active ingredients, drug targets and therapeutic mechanisms of bitter almonds-licorice for the treatment of COVID-19 remain to be elucidated. METHODS: The active ingredients and targets were derived from the Traditional Chinese Medicine Systems Pharmacology (TCMSP). Meanwhile, targets associated with COVID-19 were obtained from the GeneCards database, PharmGkb database and DrugBank database. Then, the potential targets of bitter almond-licorice against COVID-19 were screened out. Protein-protein interaction (PPI) networks and core targets were analyzed through the String database and Cytoscape software. In addition, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed based on potential targets using R statistical software. Finally, molecular docking was used to validate the binding of the active ingredients to the core targets. RESULTS: The results of the TCMSP database showed that the bitter almond-licorice had 89 active components against COVID-19, involving 102 targets. PPI network and core target analysis indicated that IL-6, TNF, MAPK1, and IL1B were the key targets against COVID-19. In addition, GO and KEGG enrichment analysis showed that the bitter almond-licorice were involved in various biological processes through inflammation-related pathways such as TNF signaling pathway and IL-17 signaling pathway. Finally, molecular docking approaches confirmed the affinity between the active components of the bitter almond-licorice and the therapeutic targets. CONCLUSION: The bitter almond-licorice could be used to treat COVID-19 by inhibiting inflammatory responses and regulating cellular stress. This work is based on data mining and molecular docking, and the findings need to be interpreted with caution.

The Diagnostic and Prognostic Value of miR-155 in Cancers: An Updated Meta-analysis.

BACKGROUND: MicroRNA-155 has been discussed as a biomarker in cancer diagnosis and prognosis. Although relevant studies have been published, the role of microRNA-155 remains uncertain because of insufficient data. METHODS: We conducted a literature search in PubMed, Embase, and Web of Science databases to obtain relevant articles and extract data to evaluate the role of microRNA-155 in cancer diagnosis and prognosis. RESULTS: The pooled results showed that microRNA-155 presented a remarkable diagnostic value in cancers (area under the curve = 0.90, 95% confidence interval (CI 0.87-0.92; sensitivity = 0.83, 95% CI 0.79-0.87; specificity = 0.83, 95% CI 0.80-0.86), which was maintained in the subgroups stratified by ethnicity (Asian and Caucasian), cancer types (breast cancer, lung cancer, hepatocellular carcinoma, leukemia, and pancreatic ductal adenocarcinoma), sample types (plasma, serum, tissue), and sample size (n >100 and n <100). In prognosis, a combined hazard ratio (HR) showed that microRNA-155 was significantly associated with poor overall survival (HR = 1.38, 95% CI 1.25-1.54) and recurrence-free survival (HR = 2.13, 95% CI 1.65-2.76), and was boundary significant with poor progression-free survival (HR = 1.20, 95% CI 1.00-1.44), but not significant with disease-free survival (HR = 1.14, 95% CI 0.70-1.85). Subgroup analyses in overall survival showed that microRNA-155 was associated with poor overall survival in the subgroups stratified by ethnicity and sample size. However, the significant association was maintained in cancer types subgroups of leukemia, lung cancer, and oral squamous cell carcinoma, but not in colorectal cancer, hepatocellular carcinoma, and breast cancer, and was maintained in sample types subgroups of bone marrow and tissue, but not in plasma and serum. CONCLUSIONS: Results from this meta-analysis demonstrated that microRNA-155 was a valuable biomarker in cancer diagnosis and prognosis.