SIRT2 interacts with DDX24 to promote nasopharyngeal carcinoma growth

Background:Nasopharyngeal carcinoma(NPC)is one of the most prevalent cancers in Southeast Asia.Sirtuin 2(SIRT2)is a member of the NAD+-dependent deacetylase family and has been shown to play important roles in numerous biological processes.However,Its function in NPC remains uncertain.The primary aim of this study is to clarify the role of SIRT2 in NPC.Methods:In this research,we examined the effect of SIRT2 silencing on NPC cell proliferation and colony formation using vitro NPC cell lines.Co-immunoprecipitation and mass spectrometry was applied to identify SIRT2-interacting proteins in NPC cells.Results:In comparison to nasopharyngeal epithelial NP69 cells,SIRT2 was up-regulated in multiple NPC cell lines,particularly in CNE2 cells.SIRT2 knockdown abrogated CNE2 cell proliferation and colony formation,whereas SIRT2 overexpression promoted HNE1 cell proliferation and colony formation.The SIRT2-interacting proteins were gathered in gene expression and regulation processes including RNA processing and translation.Among the SIRT2-interacting proteins,there were multiple DEAD-box(DDX)family members.Of note,silencing of DDX24 phenocopied the effect of SIRT2 knockdown on NPC growth.Overexpression of DDX24 restored SIRT2-depleted CNE2 cells to proliferative and colony formation.Conclusions:Our study indicates that SIRT2 can interact with DDX24 to enhance NPC growth.The clinical relevance of SIRT2 and DDX24 in NPC warrants further investigation.

A homogenous microstructural Mg-based matrix model for orthopedic application with generating uniform and smooth corrosion product layer in Ringer’s solution:Study on biodegradable behavior of Mg-Zn alloys prepared by powder metallurgy as a case

For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this research,Mg-5 wt.%Zn alloys were selected as a case.And they were impacted by hot extrusion and aging treatments to construct microstructure with different characteristics.Their selfforming corrosion product layer in Ringer’s solution,biodegradable behavior and corrosion mechanism were minutely investigated by in vitro degradation,electrochemical corrosion and cytocompatibility.The results demonstrated the extruded Mg-5 wt.%Zn alloy aged for 96 h showed high corrosion resistance,good biocompatibility for L929 and excellent ability of maintaining sample integrity during the immersion.Significantly,the alloy showed fine-grain microstructure and uniform distributed hundred nano-sized second phases,which promoted the formation of the uniform and smooth corrosion product layer at the beginning of immersion.The corrosion product layer was more stable in chloride containing aqueous solution and could be directly formed and repaired quickly,which effectively protected the matrix from further corrosion.In addition,an ideal model of Mg-based matrix for bone tissue engineering was tried to presume and propose by discussing the causal relationship between microstructure and bio-corrosion process.

Methane emission via sediment and water interface in the Bohai Sea,China

Sediment is recognized as the largest reservoir and source of methane(CH_(4))in the ocean,especially in the shallow coastal areas.To date,few data of CH_(4)concentration in sediment have been reported in the China shelf seas.In this study,we measured CH_(4)concentration in sediment and overlying seawater columns,and conducted an incubation experiment in the Bohai Sea in May 2017.CH_(4)concentration was found to be ranged from 3.075 to 1.795μmol/L in sediment,which was 2 to 3 orders of magnitude higher than that in overlying seawater columns.The surface sediment was an important source of CH_(4),while bottom seawater acted as its sink.Furthermore,the net emission rate via sediment water interface(SWI)was calculated as 2.45μmol/(m^(2)·day)based on the incubation experiment at station73,and the earthquake may enhance CH_(4)release from sediment to seawater column in the eastern Bohai Sea.

Covalent stabilization of DNA nanostructures on cell membranes for efficient surface receptor-mediated labeling and function regulations

One major challenge of using DNA nanostructures for cellular and in vivo applications is their insufficiently structural integrity that stems from the non-covalent base pairing and stacking in complex cellular and physiological environment. The establishment of covalent bonds in DNA nanostructures can link individual strands more stably and therefore should improve the performance of DNA nanostructures in different scenarios where structural integrity is required. Here, we developed a convenient and effective method for constructing covalently stabilized DNA nanostructures by chemically inserting photo-crosslinker(^(CNV)K) in DNA sequences. These covalently linked DNA nanostructures were found to be more resistant to external interference, such as low cation concentrations and unspecific displacement on cell membranes. We also demonstrated that our strategy could improve the efficiency of cell surface receptor-mediated labeling and function regulations in living cells, which sheds light on broadening the biomedical applications of DNA nanostructures.