Direct co-culture of RAW 264.7 macrophages induces morphological change and invasion of A549 cells.

<p><b>A.</b> A direct co-culture system of RAW 264.7 macrophages and A549 cells was used in this study. RAW 264.7 cells and A549 cells were plated into the same well of a culture plate. <b>B.</b> A549 cells exhibit elongated shape after culture with RAW 264.7 macrophages. The control A549 cells were plated into a 12-well plate with or without RAW 264.7 cells as described in A. Cells were pictured at the indicated time points. In the lower panel, those small cells exhibiting round shape were RAW 264.7 cells. <b>C.</b> Co-culture of RAW 264.7 macrophages induced invasion of A549 cells. Invasion assay of A549 cells was carried out as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Material and methods</a>. **<i>P</i><0.01. Results are representative of three independent experiments.</p

Proposed scheme of TP-mediated interactions between cancer cells and macrophages.

<p>Proposed scheme of TP-mediated interactions between cancer cells and macrophages.</p

Effects of I-BOP on MCP-1 expression.

<p><b>A</b> I-BOP induced transcription of MCP-1. Cells were serum-starved for 24 h before treated with 50 nM I-BOP for the indicated time periods. RNAs were isolated and RT-PCR was carried out as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>. <b>B</b> MCP-1 mRNA induction in A was confirmed by quantitative real-time PCR. **<i>p</i><0.01 compared with untreated cells. <b>C</b> Time-dependent effects of I-BOP on MCP-1 protein expression. After 24 h serum-starvation, cells were treated with 50 nM I-BOP for the indicated time periods. Media were collected and proteins in each medium were concentrated by trichloroacetic acid (TCA) precipitation as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>. Concentrated samples were quantified by Bio-Rad protein assays to ensure equal protein loading for Western blot analysis. <b>D</b> Dose-dependent effects of I-BOP on MCP-1 protein expression in A549-TPα cells. <b>E</b> I-BOP-induced MCP-1 protein expression in A549-TPβ not A549-GFP cells. <b>F</b> I-BOP-induced MCP-1 protein expression in H157 and H460 cells. <b>G</b> Comparison of I-BOP with other prostanoids on the induction of MCP-1 in A549-TPα and H460 cells. Cells were treated with 50 nM I-BOP, 1 µM PGD₂, 1 µM PGE₂ or 1 µM PGF_2α for 24 h. The concentrations of prostanoids used here were optimized to induce the most expression of MCP-1. Media were collected and assayed as described in C. Densitometric analysis of each band was made, and control untreated time point is normalized to 1. All data are representative of at least three independent experiments.</p

I-BOP regulates MCP-1 expression in SP1-dependent manner.

<p><b>A</b> Effects of TP antagonist and several protein kinases inhibitors on MCP-1 induction by I-BOP stimulation. Cells were treated with TP antagonist SQ29548 (10 µM), PKC inhibitor GF109203X (0.5 µM), and MEK inhibitor U0126 (10 µM) for 30 min before incubation with 50 nM I-BOP for 24 h. Media were collected and assayed as described in Fig. 1C. <b>B</b> Effects of SP1 inhibition on I-BOP-induced MCP-1 expression at protein levels. Cells were treated with indicated concentrations of SP1 inhibitor mithramycin A (MTM) and Hsp90 inhibitor geldanamycin (GA) for 30 min before incubation with 50 nM I-BOP for 24 h. Media were collected and assayed as described in Fig. 1C. <b>C</b> Effects of SP1 inhibition on I-BOP-induced MCP-1 expression at mRNA levels. Cells were treated with above inhibitors for 30 min before incubation with 50 nM I-BOP for 4 h. RNAs were isolated and real-time PCR was performed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>. *<i>p</i><0.05 and **<i>p</i><0.01 compared with I-BOP treated alone. <b>D</b> Protein level of SP1 was increased in the nuclei of A549-TPα cells following I-BOP stimulation. Cells were treated with 50 nM I-BOP for the indicated time periods. Nuclear extract and whole cell lysate were prepared as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Material and methods</a>. Protein level of SP1 was determined by Western blot. Densitometric analysis of each band was made and control untreated time point was normalized to 1. <b>E</b> Regulation of MCP-1 promoter activity by SP1. A549-TPα cells were transfected with luciferase reporter plasmids containing 500 bp of MCP-1 promoter sequence with either wild type or mutated SP1 binding sites. After 24 h transfection, cells were treated with vehicle control (0.1% ethanol) or 50 nM I-BOP for additional 18 h in serum free medium. Luciferase assay was carried out as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>. **<i>P</i><0.01. All data are representative of at least three independent experiments.</p

Chemotactic effects of A549-TPα conditioned media and MCP-1 on RAW 264.7 macrophages.

<p><b>A.</b> Conditioned media increased the chemotaxis of RAW cells via MCP-1. CM-C is derived from vehicle-treated cells, and CM-I is derived from I-BOP-treated cells. SFM represents serum free medium. The concentrations of anti-MCP-1 antibodies and isotype control IgG were each at 5 µg/ml original CM. The concentration of RS-102895 was 10 µM. Detailed conditions were as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and Methods</a>. **<i>P</i><0.01. <b>B</b> Effect of recombinant MCP-1 on the chemotaxis of RAW cells. MCP-1 at 1, 10 and 100 ng/ml were tested as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>.</p

Transwell co-culture of RAW 264.7 macrophages induces metastatic gene expression by A549 cells.

<p><b>A</b> A transwell co-culture system of RAW 264.7 macrophages and A549 cells was used in this study. RAW 264.7 cells and A549 cells were separately cultured for 24 h and then co-cultured in serum free medium for further 12 h or 24 h as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>. <b>B</b> Control A549 and A549-TPα cells became more scattered and spindle shaped after culture with RAW 264.7 cells. Both types of A549 cells were pictured after 12 h of culture with or without RAW 264.7 cells as described in A. <b>C</b> Co-culture of RAW 264.7 macrophages induced metastatic gene expression by A549 cells. After 12 h of co-culture with macrophages, the expression of several metastatic genes in control A549 and A549-TPα cells, including MMPs, VEGF and MCP-1 mRNA, were examined by RT-PCR as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Materials and methods</a>. <b>D</b> Co-culture of RAW 264.7 macrophages decreased E-cadherin expression by A549 cells. Control A549 and A549-TPα cells were collected after 24 h of culture with or without RAW 264.7 cells as described in A. Protein level of E-cadherin was determined by Western blot as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054073#s2" target="_blank">Material and methods</a>. All data are representative of at least three independent experiments.</p

Band-Gap Engineering <i>via</i> Tailored Line Defects in Boron-Nitride Nanoribbons, Sheets, and Nanotubes

We perform a comprehensive study of the effects of line defects on electronic and magnetic properties of monolayer boron-nitride (BN) sheets, nanoribbons, and single-walled BN nanotubes using first-principles calculations and Born–Oppenheimer quantum molecular dynamic simulation. Although line defects divide the BN sheet (or nanotube) into domains, we show that certain line defects can lead to tailor-made edges on BN sheets (or imperfect nanotube) that can significantly reduce the band gap of the BN sheet or nanotube. In particular, we find that the line-defect-embedded zigzag BN nanoribbons (LD-zBNNRs) with chemically homogeneous edges such as B- or N-terminated edges can be realized by introducing a B₂, N₂, or C₂ pentagon–octagon–pentagon (5–8–5) line defect or through the creation of the antisite line defect. The LD-zBNNRs with only B-terminated edges are predicted to be antiferromagnetic semiconductors at the ground state, whereas the LD-zBNNRs with only N-terminated edges are metallic with degenerated antiferromagnetic and ferromagnetic states. In addition, we find that the hydrogen-passivated LD-zBNNRs as well as line-defect-embedded BN sheets (and nanotubes) are nonmagnetic semiconductors with markedly reduced band gap. The band gap reduction is attributed to the line-defect-induced impurity states. Potential applications of line-defect-embedded BN nanomaterials include nanoelectronic and spintronic devices

Band-Gap Engineering <i>via</i> Tailored Line Defects in Boron-Nitride Nanoribbons, Sheets, and Nanotubes

We perform a comprehensive study of the effects of line defects on electronic and magnetic properties of monolayer boron-nitride (BN) sheets, nanoribbons, and single-walled BN nanotubes using first-principles calculations and Born–Oppenheimer quantum molecular dynamic simulation. Although line defects divide the BN sheet (or nanotube) into domains, we show that certain line defects can lead to tailor-made edges on BN sheets (or imperfect nanotube) that can significantly reduce the band gap of the BN sheet or nanotube. In particular, we find that the line-defect-embedded zigzag BN nanoribbons (LD-zBNNRs) with chemically homogeneous edges such as B- or N-terminated edges can be realized by introducing a B₂, N₂, or C₂ pentagon–octagon–pentagon (5–8–5) line defect or through the creation of the antisite line defect. The LD-zBNNRs with only B-terminated edges are predicted to be antiferromagnetic semiconductors at the ground state, whereas the LD-zBNNRs with only N-terminated edges are metallic with degenerated antiferromagnetic and ferromagnetic states. In addition, we find that the hydrogen-passivated LD-zBNNRs as well as line-defect-embedded BN sheets (and nanotubes) are nonmagnetic semiconductors with markedly reduced band gap. The band gap reduction is attributed to the line-defect-induced impurity states. Potential applications of line-defect-embedded BN nanomaterials include nanoelectronic and spintronic devices

Turning Nonmagnetic Two-Dimensional Molybdenum Disulfides into Room-Temperature Ferromagnets by the Synergistic Effect of Lattice Stretching and Charge Injection

Exploring two-dimensional (2D) room-temperature magnetic materials in the field of 2D spintronics remains a formidable challenge. The vast array of nonmagnetic 2D materials provides abundant resources for exploration, but the strategy to convert them into intrinsic room-temperature magnets remains elusive. To address this challenge, we present a general strategy based on surface halogenation for the transition from nonmagnetism to intrinsic room-temperature ferromagnetism in 2D MoS2 based on first-principles calculations. The derived 2D halogenated MoS2 are half-semimetals with a high Curie temperature (TC) of 430–589 K and excellent stability. In-depth mechanistic studies revealed that this marvelous nonmagnetism-to-ferromagnetism transition originates from the modulation of the splitting as well as the occupation of the Mo d orbitals by the synergy of lattice stretching and charge injection induced by the surface halogenation. This work establishes a promising route for exploring 2D room-temperature magnetic materials from the abundant pool of 2D nonmagnetic counterparts

Anisotropic Rolling and Controlled Chirality of Nanocrystalline Diamond Nanomembranes toward Biomimetic Helical Frameworks

Future advances in materials will be aided by improved dimensional control in fabrication of 3D hierarchical structures. Self-rolling technology provides additional degrees of freedom in 3D design by enabling an arbitrary rolling direction with controllable curvature. Here, we demonstrate that deterministic helical structures with variable rolling directions can be formed through releasing a strained nanomembrane patterned in a “utility knife” shape. The asymmetry of the membrane shape provides anisotropic driving force generated by the disparity between the etching rates along different sides in this asymmetric shape. A transient finite element method (FEM) model of diagonal rolling is established to analyze the relationships among geometries, elastic properties, and boundary conditions. On the basis of this model, a diamond-based helical framework consisting of two or three helical segments has been fabricated to mimic the shapes of natural plants. Further experiment has been done to extend this approach to other materials and material combinations, such as MoSe₂/Cr, Cr/Pt, and VO₂. To demonstrate the possible application accessible by our technology to new fields, VO₂-based helical microscale actuation has been demonstrated with photocontrollable bending in a selected region, as well as morphable and recognizable helix. This study offers a new way to construct helical mesostructures that combine special properties of the advanced materials, thus possess novel features and potential applications