Dual antioxidant activity and the related mechanisms of a novel pentapeptide GLP4 from the fermented mycelia of Ganoderma lingzhi.

Oxidative stress causes chronic inflammation, and mediates various diseases. The discovery of antioxidants from natural sources is important to research. Here we identified a novel antioxidant peptide (GLP4) from Ganoderma lingzhi mycelium and investigated its antioxidant type and potential protective mechanisms. Through free radical scavenging assay, active site shielding validation, superoxide dismutase (SOD) activity assay, and lipid peroxidation assay, we demonstrated that GLP4 was a novel protective agent with both direct and indirect antioxidant activities. GLP4 could directly enter human umbilical vein endothelial cells (HUVECs) as an exogenous substance. Meanwhile, GLP4 promoted the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) and activated the Nrf2/antioxidant response element (ARE) signaling pathway, exhibiting antioxidant and anti-apoptotic cytoprotective effects on hydrogen peroxide (H2O2)-induced HUVECs. Pull-down experiments of GLP4 target proteins, bioinformatics analysis and molecular docking further revealed that GLP4 mediated Nrf2 activation through binding to phosphoglycerate mutase 5 (PGAM5). The results suggested that GLP4 is a novel peptide with dual antioxidant activity and has promising potential as a protective agent in preventing oxidative stress-related diseases.

Unravelling the Role of LncRNA WT1-AS/miR-206/NAMPT Axis as Prognostic Biomarkers in Lung Adenocarcinoma.

Lung cancer is the world's highest morbidity and mortality of malignant tumors, with lung adenocarcinoma (LUAD) as a major subtype. The competitive endogenous RNA (ceRNA) regulative network provides opportunities to understand the relationships among different molecules, as well as the regulative mechanisms among them in order to investigate the whole transcriptome landscape in cancer pathology. We designed this work to explore the role of a key oncogene, MYC, in the pathogenesis of LUAD, and this study aims to identify important long noncoding RNA (lncRNA)-microRNA (miRNA)- transcription factor (TF) interactions in non-small cell lung cancer (NSCLC) using a bioinformatics analysis. The Cancer Genome Atlas (TCGA) database, containing mRNA expression data of NSCLC, was used to determine the deferentially expressed genes (DEGs), and the ceRNA network was composed of WT1-AS, miR-206, and nicotinamide phosphoribosyltransferase (NAMPT) bashing on the MYC expression level. The Kaplan-Meier univariate survival analysis showed that these components may be closely related prognostic biomarkers and will become new ideas for NSCLC treatment. Moreover, the high expression of WT1-AS and NAMPT and low expression of miR-206 were associated with a shortened survival in NSCLC patients, which provided a survival advantage. In summary, the current study constructing a ceRNA-based WT1-AS/miR-206/NAMPT axis might be a novel important prognostic factor associated with the diagnosis and prognosis of LUAD.

Grifolin, a potent antitumour natural product upregulates death-associated protein kinase 1 DAPK1 via p53 in nasopharyngeal carcinoma cells.

Grifolin, a secondary metabolite isolated from the fresh fruiting bodies of the mushroom Albatrellus confluens, has been shown to inhibit the growth of some cancer cell lines in vitro by induction of apoptosis in previous studies of our group. However, the mechanisms of action are not completely understood. An apoptosis-related gene expression profiling analysis provided a clue that death-associated protein kinase 1 (dapk1) gene was upregulated at least twofold in response to grifolin treatment in nasopharyngeal carcinoma cell CNE1. Here, we further investigated the role of DAPK1 in apoptotic effect induced by grifolin. We observed that protein as well as mRNA level of DAPK1 was induced by grifolin in a dose-dependent manner in nasopharyngeal carcinoma cell CNE1. We found that grifolin increased both Ser392 and Ser20 phosphorylation levels of transcription factor p53 protein, which could promote its transcriptional activity. Moreover, induced by grifolin, the recruitment of p53 to dapk1 gene promoter was confirmed to enhance markedly using EMSA and ChIP assays analysis. The involvement of DAPK1 in grifolin-induced apoptosis was supported by the studies that introducing siRNA targeting DAPK1 to CNE1 cells remarkably interfered grifolin-caused apoptotic effect as well as the activation of caspase-3. Grifolin induced upregulation of DAPK1 via p53 was also observed in tumour cells derived from human breast cancer and human colon cancer. The findings suggest that upregulation of DAPK1 via p53-DAPK1 pathway is an important mechanism of grifolin contributing to its ability to induce apoptotic effect. Since growing evidence found a significant loss of DAPK1 expression in a large variety of tumour types, grifolin may represent a promising candidate in the intervention of cancer via targeting DAPK1.

[Epigallocatechin-3-gallate interferes with EBV-encoding AP-1 signal transduction pathway].

OBJECTIVE: To elucidate the interference effect of Epigallocatechin-3-Gallate (EGCG) on targets of Activator Protein-1 (AP-1) signal transduction pathway activated by EB virus encoded latent membrane protein 1 in nasopharyngeal carcinoma (NPC) cell lines. METHODS: Survival rate of cells was determined by MTT assay. AP-1 and CyclinD1 activation were analyzed by promoter luciferase reporter system. Nuclear translocation of JNK was analyzed by indirect immunofluorescence. Protein expression and phosphorylation were observed by Western blot. RESULTS: EGCG inhibited the survival of CNE1 and CNE-LMP1 cells and the activity of AP-1 caused by LMP1 in CNE-LMP1 cells. EGCG also inhibited the nuclear translocation of JNK and the phosphorylation of c-Jun. It also inhibited cyclinD1 promoter activity and cyclinD1 expression. CONCLUSION: EGCG inhibits AP-1, JNK, c-Jun and cyclinD1 which are key targets on AP-1 signal transduction pathway. The results may explain the molecular mechanism of action of EGCG against nasopharyngeal carcinoma.

[Effect of JIP on the proliferation and apoptosis of nasopharyngeal carcinoma cells].

BACKGROUND & OBJECTIVE: Previous studies showed that JNK signaling pathway activated by LMP1 plays an important role in carcinogenesis of nasopharyngeal carcinoma (NPC). JNK interacting protein (JIP) can inhibit JNK signaling pathway in NPC cell. This study was designed to elucidate the effect of JIP on the proliferation and apoptosis of NPC cells. METHODS: After treatment with JIP at different concentrations and time points, the number of proliferating cells were determined by MTT assay; the ability of proliferation of NPC cells was measured by the rate of cloning formation; cell cycle and the apoptotic rate of NPC cells was assayed by flow cytometry. RESULTS: 1. MTT assay showed that cell proliferation was significantly inhibited by JIP in a dose- and time-dependent manner. After treatment with JIP for 24, 48, and 72 hours, the rate of survival cells were 77.8%, 59.2%, and 61.8%, respectively. 2. The number and volume of colonies were decreased after transfection with JIP. 3. The number of cells in S phase was decreased from 25.87% to 19.96%, and the number of cells in G0/G1 phase was elevated from 66.24% to 71.89% after treatment with JIP. 4. In contrast to the control group, the 24 hours apoptotic rate was elevated from 1.25% to 8.25% (about 6.6 times); the 48 hours apoptotic rate was elevated from 1.04% to 31.45% (about 30 times). CONCLUSIONS: The results demonstrated that JIP inhibit the growth of nasopharyngeal carcinoma through arresting the cell cycle at G1/S checkpoint and triggering the apoptosis of cells. Data suggest that JIP is a potent molecular drug for the treatment of the patients with nasopharyngeal carcinoma.