p53 N‑terminal binding and stabilisation by PIAS3 inhibits MDM2‑induced p53 ubiquitination and regulates cell growth

Mechanism of Compound Houttuynia Mixture as an Anti-COVID-19 Drug Based on Network Pharmacology and Molecular Docking

Objective

To explore the anti-COVID-19 active components and mechanism of Compound Houttuynia mixture by using network pharmacology and molecular docking.

Methods

First, the main chemical components of Compound Houttuynia mixture were obtained by using the TCMSP database and referring to relevant chemical composition literature. The components were screened for OB ≥30% and DL ≥0.18 as the threshold values. Then Swiss Target Prediction database was used to predict the target of the active components and map the targets of COVID-19 obtained through GeneCards database to obtain the gene pool of the potential target of COVID-19 resistance of the active components of Compound Houttuynia mixture. Next, DAVID database was used for GO enrichment and KEGG pathway annotation of targets function. Cytoscape 3.8.0 software was used to construct a “components-targets-pathways” network. Then String database was used to construct a “protein-protein interaction” network. Finally, the core targets, SARS-COV-2 3 Cl, ACE2 and the core active components of Compound Houttuyna Mixture were imported into the Discovery Studio 2016 Client database for molecular docking verification.

Results

Eighty-two active compounds, including Xylostosidine, Arctiin, ZINC12153652 and ZINC338038, were screened from Compound Houttuyniae mixture. The key targets involved 128 targets, including MAPK1, MAPK3, MAPK8, MAPK14, TP53, TNF, and IL6. The HIF-1 signaling, VEGF signaling, TNF signaling and another 127 signaling pathways associated with COVID-19 were affected ( P < 0.05). From the results of molecular docking, the binding ability between the selected active components and the core targets was strong.

Conclusion

Through the combination of network pharmacology and molecular docking technology, this study revealed that the therapeutic effect of Compound Houttuynia mixture on COVID-19 was realized through multiple components, multiple targets and multiple pathways, which provided a certain scientific basis of the clinical application of Compound Houttuynia mixture.

STAT3 and STAT5 Activation in Solid Cancers

The Signal Transducer and Activator of Transcription (STAT)3 and 5 proteins are activated by many cytokine receptors to regulate specific gene expression and mitochondrial functions. Their role in cancer is largely context-dependent as they can both act as oncogenes and tumor suppressors. We review here the role of STAT3/5 activation in solid cancers and summarize their association with survival in cancer patients. The molecular mechanisms that underpin the oncogenic activity of STAT3/5 signaling include the regulation of genes that control cell cycle and cell death. However, recent advances also highlight the critical role of STAT3/5 target genes mediating inflammation and stemness. In addition, STAT3 mitochondrial functions are required for transformation. On the other hand, several tumor suppressor pathways act on or are activated by STAT3/5 signaling, including tyrosine phosphatases, the sumo ligase Protein Inhibitor of Activated STAT3 (PIAS3), the E3 ubiquitin ligase TATA Element Modulatory Factor/Androgen Receptor-Coactivator of 160 kDa (TMF/ARA160), the miRNAs miR-124 and miR-1181, the Protein of alternative reading frame 19 (p19ARF)/p53 pathway and the Suppressor of Cytokine Signaling 1 and 3 (SOCS1/3) proteins. Cancer mutations and epigenetic alterations may alter the balance between pro-oncogenic and tumor suppressor activities associated with STAT3/5 signaling, explaining their context-dependent association with tumor progression both in human cancers and animal models.

Overexpression of GRIM-19 accelerates radiation-induced osteosarcoma cells apoptosis by p53 stabilization

AIMS

Osteosarcoma is one of the most aggressive types of primary bone cancer that responds poorly to radiotherapy frequently. The gene associated with retinoid-interferon mortality (GRIM-19) is a tumor suppressor that mediates cell apoptosis in multiple cancer types. However, the role of GRIM-19 in osteosarcoma and the underlying mechanism remain unclear. This study was designed to investigate the role and the underlying mechanism of GRIM-19 in osteosarcoma progression.

MATERIALS AND METHODS

Osteosarcoma tissues and cell lines were utilized to analyze the expressions of GRIM-19 in osteosarcoma by qRT-PCR and Western blot. Methods containing flow cytometry, irradiation exposure, cells inoculation, plasmid transfection, and protein immunoprecipitation were used to investigate the underlying mechanisms of GRIM-19 in osteosarcoma progression.

KEY FINDINGS

GRIM-19 is downregulated in osteosarcoma tissues and cell lines. Exposure to radiation induces osteosarcoma cell apoptosis by upregulation of p53 both in U2OS (p53-wt) and exogenous p53-introduced MG-63 (p53-null) osteosarcoma cells. Overexpression of GRIM-19 accelerates radiation-induced osteosarcoma cells apoptosis by p53 stabilization ex vivo and in vivo. Mechanistically, forced expression of GRIM-19 diminishes the activity of E3 ubiquitin-protein ligase mouse double minute 2 homolog (MDM2), a specific p53 protease, results in the accumulation of p53 and activation of p53-mediated apoptosis.

SIGNIFICANCE

GRIM-19 was proved to modulate radiation-induced osteosarcoma cells apoptosis in a p53 dependent manner by mediating MDM2 activity, which sheds light on the development of GRIM-19-based molecular target therapy on osteosarcoma.

Apigenin enhances the cisplatin cytotoxic effect through p53-modulated apoptosis

Epidemiological and experimental evidence suggests that dietary flavonoids, including apigenin, have anticancer roles. Apigenin has been reported to elevate p53, a critical molecule in the induction of apoptosis. The present study aimed to investigate whether apigenin, a dietary flavonoid, improves the cytotoxic effect of cisplatin in a cancer cell culture system, and to elucidate the mechanism of this effect. Multiple tumor cell types were treated with apigenin, cisplatin or both drugs. Cell viability was evaluated, and the cytotoxic effect was determined biochemically and microscopically. Treatment with apigenin increased cisplatin-induced DNA damage and the apoptosis of tumor cells in a p53-dependent manner. Apigenin, when used with cisplatin, inhibited cell proliferation and promoted mitogen-activated protein kinase activation and subsequent p53 phosphorylation, leading to p53 accumulation and upregulation of proapoptotic proteins. Cisplatin is one of the most commonly used chemotherapeutic drugs for malignant tumors, but resistance to this drug occurs. The current results therefore demonstrate that dietary flavonoids may diminish the resistance of cancers to cisplatin.

Global transcriptional profiling of longissimus thoracis muscle tissue in fetal and juvenile domestic goat using RNA sequencing

Domestic goats are important meat production animals; however, data from transcriptional profiling of skeletal muscle tissue in goat have thus far been scarce. We used comparative transcriptional profiling based on RNA sequencing of longissimus thoracis muscle tissue obtained from fetal goat muscle tissue (27 512 850 clean cDNA reads) and 6-month-old goat muscle tissue (27 582 908 reads) to identify genes that are differentially expressed, novel transcript units and alternative splicing events. Gene annotation revealed that 15 960 and 14 981 genes were expressed in the fetal and juvenile libraries respectively. We detected 6432 differentially expressed genes and, when considering GO terms, found 34, 27 and 55 terms to be significantly enriched in molecular function, cellular component and biological process categories respectively. Pathway analysis revealed that larger numbers of differentially expressed genes were enriched in fetal myogenesis or cell proliferation and differentiation-related pathways (such as Wnt), genes involved in the cell cycle and the Notch signaling pathway, and most of the differentially expressed genes involved in these pathways were downregulated in the juvenile goat library. These genes may be involved in various regulation mechanisms during muscle tissue differentiation between the two development stages examined herein. The identified novel transcript units, including both non-coding and coding RNA, as well as alternative splicing events increase the level of complexity of regulation mechanisms during muscle tissue formation and differentiation. Our study provides a comparative transcriptome analysis on goat muscle tissue, which will provide a valuable genomic resource for future studies investigating the molecular basis of skeletal muscle development.