Identification of a five-miRNA signature as a novel potential prognostic biomarker in patients with nasopharyngeal carcinoma.

BACKGROUND: MicroRNAs (miRNAs) are involved in the prognosis of nasopharyngeal carcinoma (NPC). This study used clinical data and expression data of miRNAs to develop a prognostic survival signature for NPC patients to detect high-risk subject. RESULTS: We identified 160 differentially expressed miRNAs using RNA-Seq data from the GEO database. Cox regression model consisting of hsa-miR-26a, hsa-let-7e, hsa-miR-647, hsa-miR-30e, and hsa-miR-93 was constructed by the least absolute contraction and selection operator (LASSO) in the training set. All the patients were classified into high-risk or low-risk groups by the optimal cutoff value of the 5-miRNA signature risk score, and the two risk groups demonstrated significant different survival. The 5-miRNA signature showed high predictive and prognostic accuracies. The results were further confirmed in validation and external validation set. Results from multivariate Cox regression analysis validated 5-miRNA signature as an independent prognostic factor. A total of 13 target genes were predicted to be the target genes of miRNA target genes. Both PPI analysis and KEGG analysis networks were closely related to tumor signaling pathways. The prognostic model of mRNAs constructed using data from the dataset GSE102349 had higher AUCs of the target genes and higher immune infiltration scores of the low-risk groups. The mRNA prognostic model also performed well on the independent immunotherapy dataset Imvigor210. CONCLUSIONS: This study constructed a novel 5-miRNA signature for prognostic prediction of the survival of NPC patients and may be useful for individualized treatment of NPC patients.

The ciliate Euplotes balteatus is resistant to Paralytic Shellfish Toxins from Alexandrium minutum (Dinophyceae).

Research on interactions between grazers and toxigenic algae is fundamental for understanding toxin dynamics within aquatic ecosystems and developing biotic approaches to mitigate harmful algal blooms. The dinoflagellate Alexandrium minutum is a well-known microalga responsible for paralytic shellfish toxins (PSTs) contamination in many coastal regions worldwide. This study investigated the impact of the ciliate Euplotes balteatus on cell density and PSTs transfer in simulated A. minutum blooms under controlled conditions. E. balteatus exhibited resistance to the PSTs produced by A. minutum with a density of up to 10,000 cells/mL, sustaining growth and reproduction while eliminating algal cells within a few days. The cellular PSTs content of A. minutum increased in response to the grazing pressure from E. balteatus. However, due to the substantial reduction in density, the overall toxicity of the algal population decreased to a negligible level. Most PSTs contained within algal cells were temporarily accumulated in E. balteatus before being released into the water column, suggesting unclear mechanisms for PSTs excretion in unicellular grazers. In principle, the grazing of E. balteatus on A. minutum promotes the transfer of the majority of intracellular PSTs into extracellular portions, thereby mitigating the risk of their accumulation and contamination through marine trophic pathways. However, this process also introduces an increase in the potential environmental hazards posed by extracellular PSTs to some extent.

Public avoidance and epidemics: insights from an economic model.

In this paper, we present a mathematical model of infectious disease transmission in which people can engage in public avoidance behavior to minimize the likelihood of acquiring an infection. The framework employs the economist's theory of utility maximization to model people's decision regarding their level of public avoidance. We derive the reproductive number of a disease which determines whether an endemic equilibrium exists or not. We show that when the contact function exhibits saturation, an endemic equilibrium must be unique. Otherwise, multiple endemic equilibria that differ in disease prevalence can coexist, and which one the population gets to depends on initial conditions. Even when a unique endemic equilibrium exists, people's preferences and the initial conditions may determine whether the disease will eventually die out or become endemic. Public health policies that increase the recovery rate or encourage self-quarantine by infected people can be beneficial to the community by lowering disease prevalence. However, it is also possible for these policies to worsen the situation and cause prevalence to rise since these measures give people less incentive to engage in public avoidance behavior. We also show that implementing policies that result in a higher level of public avoidance behavior in equilibrium does not necessarily lower prevalence and can result in more infections.

Dihydromyricetin Exhibits Antitumor Activity in Nasopharyngeal Cancer Cell Through Antagonizing Wnt/ß-catenin Signaling.

BACKGROUND: Cancer stem cells (CSCs) have been demonstrated to play a vital role in a diversity of biological processes in cancers. With the emergence of new evidence, the important function of CSCs in the formation of multidrug resistance of nasopharyngeal cancer has been demonstrated. Dysregulated Wnt/ß-catenin signaling pathway is an important contributor to chemoresistance and maintenance of CSCs-like characteristics. This research aims to investigate comprehensively the function of dihydromyricetin (DMY), a natural flavonoid drug, on the cisplatin (cis) resistance and stem cell properties of nasopharyngeal cancer. METHODS: In this study, the functional role of DMY in nasopharyngeal cancer progression was comprehensively investigated in vitro and in vivo, and then its relationship with CSCs-like phenotypes and multiple oncogenes was analyzed. RESULTS: In parallel assays, the growth inhibitory action of cis was enhanced by the addition of DMY in cis-resistant nasopharyngeal cancer cell lines (Hone1/cis and CNE1/cis). Functional assays showed that DMY markedly diminished the stem cell properties of nasopharyngeal cells, such as colony and tumor-sphere formation. In vivo data showed that the growth of Hone1 CSCs formed tumor xenograft was inhibited significantly by the administration of DMY. Additionally, DMY could impair the Wnt/ß-catenin signaling pathway and regulate the expression of downstream proteins in nasopharyngeal cancer cells. CONCLUSIONS: Our study clarified the anti-tumor activity of DMY through blocking the Wnt/ß-catenin signaling pathway in nasopharyngeal cancer. Therefore, DMY could be a novel therapeutic agent for nasopharyngeal cancer treatment.

Dynamics of spatial averages.

We study the dynamics of spatial averages of spatially extended dynamical systems. We present various examples of lattice dynamical systems to show the possibility of different behaviors, including asymptotically constant, periodic, and non-periodic, of spatial averages. We explain that the fluctuation in spatial averages is caused by the transitivity and the lack of symmetry of the dynamics of local subsystems. (c) 1997 American Institute of Physics.

[Comparison on concentrations and quality of dissolved organic matter in throughfall and stemflow in a secondary forest of Castanopsis carlesii and Cunninghamia lanceolata plantation].

In this paper, monthly variation of dissolved organic matter (DOM) concentrations as well as humification and aromaticity indices in throughfall and stemflow from secondary broadleaved Castanopsis carlesii (BF) forest and Cunninghamia lanceolata plantation (CP) were measured. The DOC concentrations in throughfall were significantly higher with greater variation in BF than in CP. The concentrations of DOC in throughfall were averagely 7.2 and 3.2 times of those in rainfall in BF and CP forests, respectively. The DOC concentrations of stemflow in CP were averagely 2.5 times as much as those in BF, and the DOC concentrations in stemflow tended to be greater in dry season than in rain season for the two forests. A significantly negative relationship was' found between the DOC concentrations in stemflow and the amounts of stemflow for both BF and CP. Moreover, the humification and aromaticity indices of DOM in throughfall in BF was significantly greater than in CP. In contrast, the humification and aromaticity indices of DOM from stemflow of CP were significantly greater than those of BF. This result indicated that the structure of DOM from throughfall was more complex in BF than in CP, and the structure of DOM from stemflow was vice versa. These results indicated that DOM in stemflow and throughfall showed significant variations in quantity and quality between BF and CP and may greatly impact the accumulation of soil organic carbon.