铜绿假单胞菌注射液对NCI-N87胃癌细胞株增殖能力的影响及其机制研究

目的 探讨铜绿假单胞菌注射液（Pseudomonas aeruginosa mannose-sensitive hemagglutinin,PA-MSHA）对NCI-N87胃癌细胞增殖能力的影响及其分子作用机制。方法 MTT法检测PA-MSHA对NCI-N87胃癌细胞增殖的影响,流式细胞术检测细胞凋亡率,划痕实验和侵袭实验检测细胞迁移和侵袭能力的变化,Western Blot检测PTEN蛋白和p-AKT蛋白的表达变化,转染PTEN siRNA敲低PTEN表达后,再次行MTT法检测PA-MSHA对细胞增殖的影响。结果 PA-MSHA抑制NCI-N87胃癌细胞的增殖具有剂量和时间依赖性。与对照组比较,NCI-N87细胞经PA-MSHA处理后,凋亡率显著增加（P<0.05）,迁移和侵袭能力显著下降（P<0.05）。与对照组比较,PA-MSHA显著提高PTEN蛋白表达,降低p-AKT蛋白表达（P<0.05）。通过siRNA转染敲低PTEN表达后,PA-MSHA抑制NCI-N87细胞增殖的能力较对照组显著下降（P<0.05）。结论 PA-MSHA对NCI-N87胃癌细胞具有抑制增殖、促进凋亡、抑制侵袭转移的作用,其机制与PTEN/AKT信号通路有关。     

Simultaneous detection of As and Se in polyester resin skin phantoms

It is known that As and Se act as metabolic antagonists. Hence, an improvement in assessing As-related health risks can be achieved by simultaneous quantitative measurements of both As and Se levels in the human body. In this paper, the simultaneous detection of trace concentrations of As and Se in polyester resin skin phantoms was demonstrated. The experiments were performed with a commercial miniature X-ray tube and silicon PiN detector X-ray fluorescence (XRF) system. No significant overlap between the K_α peaks of the two elements was observed. Minimum detection limits of (1.05±0.02) μg As g^?1 and (0.88±0.02) μg Se g^?1 were found.     

Study on the oxidation form of adenine in phosphate buffer solution

The oxidation of adenine in phosphate buffer solution is investigated using square-wave voltammetry and in situ UV spectroelectrochemistry. The geometry of adenine and the derivatives optimized at DFTB3LYP-6-31G (d, p)-PCM level is in agreement with the crystal structure, and the imitated UV spectra of adenine and the product at electrode are consistent with the in situ UV spectra. The relationship between the electrochemical property and the molecular structure is also discussed. The experimental and theoretical results show that the adenine oxidation origins from the neutral adenine.     

ROS-mediated autophagy was involved in cancer cell death induced by novel copper(II) complex

In this study, we investigated autophagy induced in HeLa cells by copper(II) complex of ethyl 2-[bis(2-pyridylmethyl)amino] propionate ligand (ETDPA) (formula: [(ETDPA)Cu(phen)](ClO4)2 (abbreviated as LCu),a novel synthetic copper(II) complex whose DNA binding activity has been proved. Cell viability, autophagic levels and generation of ROS were evaluated following the exposure to LCu. LCu-induced cell death in a dose- and time-dependent manner, which was demonstrated by enhanced fluorescence intensity of monodansylcadervarine (MDC), as well as elevated expression of autophagy-related protein MAP-LC3. These phenomena were all attenuated after pretreatment with autophagy inhibitors 3-MA or NH₄Cl. Furthermore, our data indicated that LCu-triggered autophagy through ROS: cellular ROS levels were increased after LCu treatment, which was reversed by ROS scavenger NAC (N-acetylcysteine). As a consequence, Lcu-mediated autophagy was partly blocked by NAC. In summary, we synthezied a novel copper(II) complex and showed that this compound was effective in killing HeLa cells via ROS-triggered autophagic pathway.