Correction: Caveolin-1-mediated STAT3 activation determines electrotaxis of human lung cancer cells.

[This corrects the article DOI: 10.18632/oncotarget.21306.]

Biological electric fields guide directional migration and promote epithelial–mesenchymal transition in lung cancer

Background: Endogenous direct-current electric fields (dcEFs), as one of the essential biophysical signals that naturally occur in the tumor microenvironment, were previously demonstrated to suppress the cytotoxicity of the third-generation tyrosine kinase inhibitor osimertinib in epidermal growth factor receptor (EGFR)-mutant lung cancer. Materials and Methods: In the current study, we further investigated the electrotactic response of EGFR-mutant lung cancer with different osimertinib sensitivity, including osimertinib-sensitive PC-9GR cells and osimertinib-resistant PC-9GROR cells. Results: Firstly, in murine subcutaneous xenografts, robust endogenous electric currents were detected at the surface of tumors derived from osimertinib-resistant cells with a highly sensitive vibrating probe. Next, the electrotactic responses of two cell lines under EFs of different intensities were studied. Both PC-9GR and PC-9GROR cells exhibited directionally cathodal migration in a voltage-dependent manner, and osimertinib-resistant PC-9GROR cells displayed higher migration speeds. Epithelial-mesenchymal transition (EMT), which was previously reported to be closely related to tumor invasion and metastasis and could be suppressed by osimertinib, was enhanced under EF stimulation as reflected by increased vimentin and decreased E-cadherin in PC-9GR cells via Western blotting and immunofluorescent staining regardless of osimertinib treatment. Additionally, pharmacological inhibition of phosphoinositide 3-kinase/protein kinase B (AKT) signals reduced electrotaxis and EMT. Conclusion: Taken together, these results suggested that activation of AKT pathway may play an important role in electrotaxis and EMT of EGFR-mutant lung cancer

Dynamic Reversible Evolution of Wrinkles on Floating Polymer Films under Magnetic Control

In this paper, we present a simple and versatile method to dynamically and reversibly tailor surface wrinkles on a floating polymer film by combining a magnetic droplet and neodymium magnet. The magnetic force from the attraction of the neodymium magnet to the magnetic droplet is the main reason for surface instabilities of floating polymer films, which can induce radial stress in the radial direction, and further, compressive stress in the circumferential direction. This compressive stress can trigger not only floating film wrinkling but also a wrinkle-fold transition. Surface morphologies on the floating polymer film have been systematically studied, by varying the distance between the magnetic droplet and neodymium magnet, polymer film thickness, and magnetic droplet volume. With the decrease in the distance between a magnetic droplet and a neodymium magnet, the decrease in polymer film thickness, and the increase in the magnetic droplet volume, the wrinkle numbers increase and even a wrinkle-fold transition happens. Additionally, the coupling effect of multiple magnetic droplets on the floating film has also been used to achieve novel surface wrinkle patterns, which greatly widens the applications of surface wrinkling

Hydrothermal growth of large-scale micropatterned arrays of ultralong ZnO nanowires and nanobelts on zinc substrate

Large-scale, ultralong ZnO nanowire and nanobelt arrays with honeycomb-like micropatterns have been fabricated by hydrothermal oxidation of zinc foil in aqueous alkaline (NH4)2S2O8 solutions

Swelling/Deswelling-Induced Reversible Surface Wrinkling on Layer-by-Layer Multilayers

Layer-by-layer (LbL) multilayer film is incorporated in the fabrication of a film/substrate system for the investigation of swelling/deswelling-induced wrinkle evolution for the first time. As one typical example, hydrogen-bonded (PAA/PEG)_<i>n</i> (PAA, poly­(acrylic acid); PEG, poly­(ethylene glycol)) is deposited on a poly­(dimethylsiloxane) (PDMS) substrate via the LbL technique. Heating treatment causes the covalent cross-linking reaction to occur in the H-bonded multilayers with simultaneously spontaneous formation of labyrinth wrinkles. Subsequent water immersion leads to the evolution of a series of the swelling-sensitive wrinkles in the thermally cross-linked (PAA/PEG)_<i>n</i>/PDMS bilayer, ranging from initial labyrinth wrinkles (a) to an intermediate smooth wrinkle-free state (b), hexagonally arranged dimples (c), and the later-segmented labyrinth patterns (d). Upon deswelling by reheating of the swollen bilayer, the reverse wrinkle evolution happens via the process of d → b, or d → b → a, or c → b, or c → b → a, which is dependent on the reheating temperature and the swelling-induced pattern. We investigate the influences of experimental conditions on the swelling kinetics and the resulting wrinkle evolution, which include the thickness of (PAA/PEG)_<i>n</i>, the additionally deposited outermost layer (e.g., Pt and polystyrene), and the swelling solution pH. The involved mechanism has been discussed from the viewpoint of the relation between the wrinkling behavior and the swelling/deswelling-induced stress state. The results indicate that the combined strategy of LbL assembly with the introduction of additional layers endows us with considerable freedom to fabricate multifunctional film/substrate systems and to tune the instability-driven patterns for advanced properties and extended applications

Swelling/Deswelling-Induced Reversible Surface Wrinkling on Layer-by-Layer Multilayers

Layer-by-layer (LbL) multilayer film is incorporated in the fabrication of a film/substrate system for the investigation of swelling/deswelling-induced wrinkle evolution for the first time. As one typical example, hydrogen-bonded (PAA/PEG)_<i>n</i> (PAA, poly­(acrylic acid); PEG, poly­(ethylene glycol)) is deposited on a poly­(dimethylsiloxane) (PDMS) substrate via the LbL technique. Heating treatment causes the covalent cross-linking reaction to occur in the H-bonded multilayers with simultaneously spontaneous formation of labyrinth wrinkles. Subsequent water immersion leads to the evolution of a series of the swelling-sensitive wrinkles in the thermally cross-linked (PAA/PEG)_<i>n</i>/PDMS bilayer, ranging from initial labyrinth wrinkles (a) to an intermediate smooth wrinkle-free state (b), hexagonally arranged dimples (c), and the later-segmented labyrinth patterns (d). Upon deswelling by reheating of the swollen bilayer, the reverse wrinkle evolution happens via the process of d → b, or d → b → a, or c → b, or c → b → a, which is dependent on the reheating temperature and the swelling-induced pattern. We investigate the influences of experimental conditions on the swelling kinetics and the resulting wrinkle evolution, which include the thickness of (PAA/PEG)_<i>n</i>, the additionally deposited outermost layer (e.g., Pt and polystyrene), and the swelling solution pH. The involved mechanism has been discussed from the viewpoint of the relation between the wrinkling behavior and the swelling/deswelling-induced stress state. The results indicate that the combined strategy of LbL assembly with the introduction of additional layers endows us with considerable freedom to fabricate multifunctional film/substrate systems and to tune the instability-driven patterns for advanced properties and extended applications

Large-Area Patterning of Polyaniline Film Based on <i>in Situ</i> Self-Wrinkling and Its Reversible Doping/Dedoping Tunability

Here we report a simple one-pot yet robust approach to fabricate large-scale wrinkle patterns with reversible acid-doping/base-dedoping tunability. A novel swelling-induced self-wrinkling mechanism is responsible for the <i>in situ</i> growth of wrinkled polyaniline (PANI) film on polydimethylsiloxane (PDMS) substrate. The spontaneously formed wrinkles with controlled microstructures such as the wavelength, spatial orientation, and location have been well regulated by PANI film thickness (via polymerization time and monomer concentration) and PDMS substrate modulus as well as the boundary conditions imposed by the substrate. The results indicate that the <i>in situ</i> self-wrinkling is highly desirable for patterning PANI film over large areas with the instability-driven morphologies, even in the case of curved surfaces employed. Interestingly, taking advantage of the swelling/deswelling capability via the unique acid doping/base dedoping of PANI, we have further realized unprecedented reversible modulation between the wrinkled and dewrinkled states. The involved physics underlying the complicated <i>in situ</i> self-wrinkling and the reversible doping/dedoping tunability has been revealed

Radiosensitization of clioquinol and zinc in human cancer cell lines

Abstract Background We previously reported that clioquinol acts as a zinc ionophore and inhibits the NF-κB signalling pathway. Other research has demonstrated that zinc deficiency plays a vital role in the occurrence and development of some solid tumours, and intracellular zinc supplementation may reverse this process and enhance the tumour sensitivity to anticancer treatment. Thus, we investigated the radiosensitization effects of clioquinol combined with zinc on HeLa and MCF-7 cells in vitro. Methods The dose effect of growth inhibition of clioquinol combined with zinc on cell viability was determined by a cell counting kit 8 (CCK-8) assay. The radiosensitization effect of clioquinol combined with zinc and/or MG132 in HeLa and MCF-7 cells was detected by the clonogenic assay. The cell cycle distribution and apoptosis of clioquinol combined with zinc on HeLa cells were analyzed by flow cytometry. A luciferase reporter construct was used to study the effect of clioquinol combined with zinc on NF-κB activity in HeLa cells. DNA double-strand breaks were detected by immunofluorescence. The mRNA and protein levels of ATM were analyzed by quantitative real-time PCR and Western blotting, respectively. Results Our research showed that clioquinol combined with zinc markedly increased the radiosensitivity of HeLa and MCF-7 cells in low toxic concentrations and resulted in a post-irradiation decrease in G2 phase arrest and an increase in apoptosis. Clioquinol combined with zinc also inhibited NF-κB activation, decreased ATM expression and increased DNA double-strand breaks (DSBs) induced by ionizing radiation. Conclusions These findings indicated that clioquinol combined with zinc enhanced the radiosensitivity of HeLa and MCF-7 cells by the down-regulation of ATM through the NF-κB signalling pathway