Objective TePixD (Tll0078) is a blue light -using flavin (BLUF) photoreceptor protein from Thermosynechococcus elongatus BP -1. TePixD protein has a conserved Tyr8-Gln50-Met93 triad around the FAD pocket to mediate the proton -coupled electron transfer (PCET) process. But the detailed light response mechanism needs further study. We aimed to elucidate the structure and biochemical properties of TePixD mutants at key light response sites to analyze the light response process of TePixD. Methods We employed X-ray crystallography to resolve the crystal structure of the TePixD Y8F mutant. The side chain of Tyr8 is involved in PCET while Phe8 in mutation loses the function due to the loss of its hydroxyl group. We compared the structure of TePixD Y8F mutation to TePixD wild type (WT) and its homology protein SyPixD Y8F. Using multi -angle light scattering (MALS), we analyzed the oligomerization of multiple TePixD mutations (Y8F, Q50L, W91F, Y8F/W91F, and Q50L/W91F), focusing specifically on mutational sites that are critical residues for the protein's photo response to dark and light conditions. Results We resolved the crystal structure of TePixD Y8F mutant at a resolution of 2.54 angstrom and found that it shares a similar overall structure with the TePixD WT but exhibits significant differences from the SyPixD Y8F structure. Biochemical analysis revealed differences in molecular mass and elution profiles between the TePixD mutants and the WT under dark and light conditions, indicating the perturbation on the light -induced conformational change by the mutants. Conclusion Our structure determination and biochemical analyses will add information to reveal the light response mechanism of BLUF proteins.

Cationic polymers, especially polyethyleneimine (PEI) , have received much attention in the field of non-viral vectors, for their better biological safety and high efficiency gene transfection. However, their higher positive charge density will produce greater cytotoxicity , and also, easily forming larger particles with protein, which limits their further usage in vivo. In this work, we designed a shielding system based on polyglutamic acid-polyethylene glycol@ calcium carbonate (PPG@ CaCO3) for shielding polyethyleneimine (PEI). On one hand, PGA-PEG (PPG) can reduce the cytotoxicity caused by PEI, and is conducive to applied in vivo. On the other hand, CaCO3 effectively offset the decreased transfection efficiency that caused by PPG, and even enhanced cell transfection efficiency of PEI. Compared with the polyglutamic acid-polyethylene glycol@ calcium phosphate [PPG@ Ca-3(PO4)(2)], CaCO3 releases carbon dioxide gas in acidic environment, which is a key factor to improve cell transfection efficiency. In vivo circulation experiments in mice show that the shielding system based on PPG@ CaCO3 can effectively enhance long circulation. Therefore, the shielding system plays an important role in promoting the in vivo application of cationic gene vectors.

目的:探讨放射性碘治疗(RAI)中131I治疗分化型甲状腺癌(DTC)功能性肺转移的短期疗效及其影响因素.方法:分析在医院行RAI的16例发生功能性肺转移的DTC患者,所有患者均行131I治疗,每次131I治疗前1月内行颈部超声、胸部CT检查,治疗前3～4 d测定血清甲状腺功能的T3、T4、FT3、FT4、Tg、抗甲状腺球蛋白抗体(TgAb)和促甲状腺激素(TSH)水平,131I治疗后5～7 d行131I单光子发射型电子计算机断层扫描/CT(SPECT/CT),治疗后2～3个月后复查并进行疗效评估,根据131I治疗的功能性肺转移的短期疗效将16例患者分为完全缓解(CR)组(11例),部分缓解(PR)组(4例),无效(NR)组(1例),并且分析不同疗效的影响因素.结果:在行131I治疗的16例功能性肺转移的DTC患者中,CR组11例,PR组4例,NR组1例.16例功能性肺转移DTC患者治疗总有效率为93.75％(15/16).3组末次手术与首次131I治疗间隔、肺外转移情况及首次131I治疗前血清Tg水平比较,差异有统计学意义(x2=4.535,x2=6.541,x2=5.403;P<0.05).病理类型、性别、诊断DTC时年龄、有无甲状腺外侵犯、有无甲状腺被膜外纤维组织和横纹肌侵犯、有无神经侵犯、有无脉管瘤栓和淋巴结转移个数、手术次数、131I治疗次数及131I累积剂量在3组间差异无统计学意义.结论:RAI是治疗DTC患者术后发生功能性肺转移的有效方法,患者短期治疗疗效良好.131I的治疗疗效与末次手术与首次131I治疗间隔时间、肺外转移情况以及首次131I治疗前Tg水平相关.

BACKGROUND:Tumor cells undergoing epithelial-mesenchymal transition (EMT) display enhanced ability to enter the circulation, thereby being major source of circulating tumor cells (CTCs). In this study, we aimed to better understand the roles of CTC undergoing EMT in monitoring cancer progression. METHODS:We analyzed gene expression profiling of epithelial and mesenchymal markers in lung or colon tumor samples by mining TCGA database. We detected CTCs and classify their EMT phenotypes of 31 patients with lung or colon cancer by using a CanPatrol CTC-enrichment technique. RESULTS:The bioinformatic analysis indicated that mesenchymal markers were expressed in a subset of lung tumor samples, and its high expression was associated with poor survival of lung cancer patients. However, in colon cancer, majority of tumor samples expressed hybrid epithelial/mesenchymal markers. CTC analysis with EMT classification showed that the number of CTCs with mesenchymal phenotype was high in lung cancer patients with the advanced stage. Dynamic CTC analysis in a lung cancer patient indicated that CTC with mesenchymal phenotype was effective to monitor tumor progression. In a colon cancer patient, dynamic CTC analysis indicated that CTC with hybrid epithelial/mesenchymal phenotypes was an effective biomarker to guide therapy. CONCLUSIONS:Encouraging results from this proof-of-concept study show that CTC with mesenchymal phenotype or hybrid epithelial/mesenchymal phenotypes could be a potential biomarker for monitoring tumor progression in lung or colon cancer respectively.

Cells compartmentalize enzymes for broad physiological functions such as efficient metabolic reactions and spatiotemporally controlled signaling. A given enzyme or enzyme complex can participate in multiple cellular processes in response to different signal inputs by forming different cellular compartments. Here, we demonstrate that association of GIT1 and β-Pix, a pair of GTPase regulatory enzymes involved in diverse cellular processes, leads to autonomous condensation of the complex via phase separation without additional scaffolding molecules. The atomic structure of the GIT/PIX complex reveals the molecular basis governing the phase separation-mediated condensation of the GIT1/β-Pix complex. Importantly, the GIT1/β-Pix condensates can function as a versatile modular membrane-less organelle- like structure for distinct cellular compartmentalization by binding to upstream proteins such as Paxillin in focal adhesions, Shank3 in neuronal synapses, and Scribble in cellular junctions. Thus, phase separation-mediated formation of condensed enzyme complexes provides a powerful way of dynamically concentrating limited amounts of cooperating enzymes to specific cellular compartments for optimal signaling.

The invention provides a modified hyaluronic acid shielded metal organic frame, nano particles, a preparation method and application of the nano particles. The modified hyaluronic acid shielded metalorganic frame is prepared from hyaluronic acid modified by poly-dopamine and a metal organic frame; and the metal organic frame is prepared through a microwave reaction of ferric trichloride hexahydrate and trimesic acid. The modified hyaluronic acid shielded metal organic frame can load curcumin through the pore adsorption effect and the chemical adsorption effect, and the obtained nano particlescan achieve a diagnosis and treatment integrated function of photo-thermal therapy, drug therapy and photoacoustic imaging. The nano particles further have strong photoacoustic imaging signals, meanwhile have a high cell kill rate when being applied to the photo-thermal therapy, and have a high cell kill rate when being applied to photo-thermal and medicine combined therapy. Hyaluronic acid modified by poly-dopamine shields the surface of the metal organic frame, so that the prepared nano particles have the good dispersity and targeting ability of a CD 44 receptor of cancer cells.

Intrinsically integrating precise diagnosis, effective therapy, and self-anti-inflammatory action into a single nanoparticle is attractive for tumor treatment and future clinical application, but still remains a great challenge. In this study, bovine serum albumin-iridium oxide nanoparticles (BSA-IrO2 NPs) with extraordinary photothermal conversion efficiency, good photocatalytic activity, and a high X-ray absorption coefficient were prepared through one-step biomineralization. The nanoparticles allow tumor phototherapy and simultaneous photoacoustic/thermal imaging and computed tomography. More importantly, BSA-IrO2 NPs can also act as a catalase to protect normal cells against H2O2-induced reactive oxygen pressure and inflammation while significantly enhancing photoacoustic imaging through microbubble-based inertial cavitation. These remarkable features may open up the exploration iridium-based nanomaterials in theranostics.

Nano-therapeutic approach for clinical implementation of tumors remains a longstanding challenge in the medical field. The main challenges are rapid clearance, offtarget effect and the limited role in the treatment of metastatic tumors. Toward this objective, a cell-mediated strategy by transporting photothermal reagents and CpG adjuvant within macrophage vehicles is performed. The photothermal reagents are constructed by conjugating of hyperbranched polyethyleimine (PEI) to golden nanorode (GNR) via S-Au bonds. GNR-PEI/CpG nanocomposites, formed via electrostatic interaction and displayed excellent near-infrared (NIR) photothermal performance, exhibit immense macrophage uptake and negligible cytotoxic effect, which is essential for the fabrication of GNR-PEI/CpG loaded macrophages. GNR-PEI/CpG loaded macrophages demonstrated admirable photothermal response in vitro . Benefited from the functionalization of the binding adhesion between macrophages and 4T1 cells, GNR-PEI/CpG loaded macrophages significantly promoted tumor accumulation in vivo and dramatically enhanced the efficiency of photothermal cancer therapy. Moreover, the immune system is activated after photothermal therapy, which is mainly attributed to the generation of tumor specific antigens and CpG adjuvant in situ . Our findings provide a potential cell-mediated nanoplatform for tumor therapy by combination of near infrared photothermal therapy and immunotherapy.

To search safe and evaluate non-viral nucleic acids carrier, a series of polyphenylalanine and phenylalanine grafted low molecular weight PEI with a molecular weight of 1.8 x 10(3) (PEI1.8k-g-PPhe and PEI1.8k-g-Phe) were prepared by NCA ring opening polymerization initiated by PEI-1.8k and phenylalanines conjugation to PEI-1.8k, respectively. The polymers and the complexes of PEI1.8k-g-PPhe/DNA and PEI1.8k-g-Phe/DNA were characterized by nuclear magnetic resonance (NMR) analysis, particle size analysis, zeta potential analysis, luciferase analysis, flow cytometry (FCM) analysis and confocal laser scan microscopy (CLSM). In order to compare the property for compacting DNA into nanoparticles, the particle size and zeta potential analysis were carried out. Both PEI1.8k-g-PPhe and PEI1.8k-g-Phe showed suitable particle size and zeta potential for gene delivery. The particle size of PEI1.8k-g-PPhe10/DNA complexes were about 150 nm and the zeta potentials were about +16 mV, which were suitable for the in vitro experiments. Moreover, cell viability, after treating with different copolymers at various concentrations, was studied by an MTT assay. The reduced cytotoxicity of PEI1.8k-g-PPhe and PEI1.8k-g-Phe may be because of the introduction of neutral hydrophobic phenylalanine moieties. And both of the PEI1.8k-g-PPhe and PEI1.8k-g-Phe had lower cytotoxicity (above 70% viability at a higher concentration 1 mg/mL) than that of PEI with a molecular weight of 2.5 x 10(4) (PEI-25k) in HeLa cells. The in vitro gene transfection of PEI1.8k-g-PPhe10 and PEI1.8k-g-Phe10 was conducted in human cervical cancer (HeLa) and breast cancer (MCF-7) cells. In both of the cells, PEI1.8k-g-PPhe10 exhibited much higher gene transfection efficiency. PEI1.8k-g-PPhe10/DNA complexes showed remarkable gene transfection efficiency, which was about twelve times higher than that of PEI-25k. The endocytosis efficiency of PEI1.8k-g-PPhe10/DNA and PEI1.8k-g-Phe10/DNA were quantified using flow cytometry. Due to their regular polymer chain, PEI1.8k-g-PPhe10/Cy5-DNA showed better internalization efficiency than PEI1.8k-g-Phe10/Cy5-DNA, PEI-25k/Cy5-DNA and PEI-1.8k/Cy5-DNA. The CLSM assay was carried out to verify the internalization efficiency together which also indicated that PEI1.8k-g-PPhe10/Cy5-DNA induced higher intracellular uptake efficiency than the others.

RGD peptides were grafted to the carboxyl groups of poly(glutamic acid) to get a targeting shielding carrier (PGA-RGD) for polyethyleneimine (PEI) gene carrier. The experiment results showed that PGA-RGD can effectively shield PEI/DNA complex particles. Gel retardation assay showed that DNA can not be released by PGA-RGD from complexes under experimental conditions for gene transfection. For PGA/PEI/DNA system, its gene transfection efficiency obviously decreased because PGA shielding carrier coating on PEI/DNA complex decreased the surface charges of the complex particles. On the other hand, for PGA-RGD/PEI/DNA shielding system, although its surface charges were decreased by PGA-RGD shielding, its gene transfection efficiency were effectively improved because of the specific binding affinity between RGD and receptors on tumor endothelial cell membranes. MTT assay further presented that PGA-RGD/PEI/DNA has better biocompatibility than PEI/DNA. The improvement method developed in this paper for gene carriers can not only shield the positive charges on complex particles and decrease the non-specific uptake by non-targeting cells, but also introduce targeting functions to gene carrier system. The shielding system for gene complex particles is an effective strategy for promoting in vivo application of polycation gene carriers.