Tumor cells-derived extracellular vesicles carry circ_0064516 competitively inhibit microRNA-6805-3p and promote cervical cancer angiogenesis and tumor growth

The current study tried to elucidate the regulatory role of tumor cell-derived exosomes (Exos)-circ_0064516 in angiogenesis and growth of cervical cancer. Related cirRNAs and downstream target genes were identified through bioinformatics analysis. Exos were isolated from cervical cancer cell line CaSki, followed by co-cultured with human umbilical vein endothelial cells (HUVECs). Then, the roles of circ_0064516, miR-6805-3p, and MAPK1 in migration and angiogenesis of HUVECs were assayed. Furthermore, xenografted tumors were transplanted into nude mice for in vivo validation. In vitro assay validated highly expressed circ_0064516 in cervical cancer cells. Tumor cell-derived Exos carried circ_0064516 to HUVECs. circ_0064516 increased MAPK1 expression by binding to miR-6805-3p, thus enhancing migration and angiogenesis. Exos containing circ_0064516 also promoted tumorigenesis of cervical cancer cells in nude mice. We confirmed the oncogenic role of tumor cell-derived Exos carrying circ_0064516 in cervical cancer progression through miR-6805-3p/MAPK1.</p

Selective and High Sorption of Perfluorooctanesulfonate and Perfluorooctanoate by Fluorinated Alkyl Chain Modified Montmorillonite

A novel fluorinated montmorillonite (F-MT) was synthesized via exchange of cationic fluorinated surfactant to selectively adsorb perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) from water. F-MT displayed fast and high sorption for PFOS and PFOA at concentrations below 10 μg/L, and performed better than the best activated carbon and resin previously reported. The spent F-MT can be completely regenerated by methanol solution and can be reused five times without reduction in sorption capacity. Moreover, the F-MT possessed excellent selectivity for PFOS and PFOA in the presence of other organic pollutants. The coexisting phenol, pyridine, dodecylbenzenesulfonate (SDBS), and phenanthrene (PHE) exhibited no effect on PFOS and PFOA sorption. Due to the nanoscale interlayer structure and chemical nature of F-MT, macromolecular humic acid had little effect on PFOS and PFOA sorption. Also, F-MT adsorbed very little SDBS and PHE. The results of competitive sorption and density functional theory calculations verified that PFOS and PFOA were adsorbed on the C–F chain of F-MT, while PHE and SDBS sorption occurred on the hydrocarbon part of F-MT. The unique hydro-oleophobic C–F chain on the F-MT was responsible for selective sorption of perfluoroalkyl acids (PFAAs), providing a new mechanistic insight for the interactions between PFAAs and fluorinated adsorbents. In addition, F-MT offers promising potential for removal of PFOS and PFOA from contaminated water

Selective and Fast Adsorption of Perfluorooctanesulfonate from Wastewater by Magnetic Fluorinated Vermiculite

A novel magnetic fluorinated adsorbent with selective and fast adsorption of perfluorooctanesulfonate (PFOS) was synthesized via a simple ball milling of Fe₃O₄ and vermiculite loaded with a cationic fluorinated surfactant. The loaded Fe₃O₄ nanoparticles increased the dispersibility of fluorinated vermiculite (F-VT) in water and allowed the magnetic separability. The nanosized Fe₃O₄ was homogeneously embedded into the adsorbent surfaces, improving the hydrophilicity of F-VT external surface, and this hybrid adsorbent still kept the hydrophobic fluorinated interlayer structure. With this unique property, Fe₃O₄-loaded F-VT has very fast and selective adsorption for PFOS in the presence of other compounds, due to the fluorophilicity of C–F chains intercalated in the adsorbent interlayers. This novel adsorbent has a high sorption capacity for PFOS, exhibiting PFOS removal from fire-fighting foam wastewater that is much higher than that of powdered activated carbon and resin due to its high selectivity for PFOS. The used Fe₃O₄-loaded F-VT was successfully regenerated by methanol and reused five times without reduction in PFOS removal and magnetic performance. The Fe₃O₄-loaded F-VT demonstrates promising application for PFOS removal from real wastewater

Role of Air Bubbles Overlooked in the Adsorption of Perfluorooctanesulfonate on Hydrophobic Carbonaceous Adsorbents

Hydrophobic interaction has been considered to be responsible for adsorption of perfluorooctanesulfonate (PFOS) on the surface of hydrophobic adsorbents, but the long C–F chain in PFOS is not only hydrophobic but also oleophobic. In this study, for the first time we propose that air bubbles on the surface of hydrophobic carbonaceous adsorbents play an important role in the adsorption of PFOS. The level of adsorption of PFOS on carbon nanotubes (CNTs), graphite (GI), graphene (GE), and powdered activated carbon (PAC) decreases after vacuum degassing. Vacuum degassing time and pressure significantly affect the removal of PFOS by these adsorbents. After vacuum degassing at 0.01 atm for 36 h, the extent of removal of PFOS by the pristine CNTs and GI decreases 79% and 74%, respectively, indicating the main contribution of air bubbles to PFOS adsorption. When the degassed solution is recontacted with air during the adsorption process, the removal of PFOS recovers to the value obtained without vacuum degassing, further verifying the key role of air bubbles in PFOS adsorption. By theoretical calculation, the distribution of PFOS in air bubbles on the adsorbent surfaces is discussed, and a new schematic sorption model of PFOS on carbonaceous adsorbents in the presence of air bubbles is proposed. The accumulation of PFOS at the interface of air bubbles on the adsorbents is primarily responsible for its adsorption, providing a new mechanistic insight into the transport, fate, and removal of PFOS

Quantitative ELISA assay to verify the interaction of p50 with PCNA.

<p><b>A:</b> Coomassie blue stained SDS-PAGE analysis for the highly purified proteins used in ELISA assays. M, protein marker in kDa; Lane 1, highly purified His-p68. Lane 2, highly purified non-tagged p50. <b>B:</b> Interaction of p50 with PCNA by adding PCNA to coated p50. The assays were performed as described in “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027092#s2" target="_blank">Materials and Methods</a>”. The 96-well plates were coated with 100 ng of p50, His-p68 and BSA. ELISAs using increasing amounts of PCNA (horizontal axis) were then performed using an antibody PC-10 to detect the bound PCNA to p50. The p68 was taken as positive control while BSA was taken as “noise”. Absorbance readings were taken at 450 nm and the values were plotted after subtraction of the control values with BSA. Each assay was performed three times and the standard deviations are shown by the error bars. <b>C:</b> Interaction of p50 with PCNA by adding p50 to coated PCNA. The 96-well plate was pre-coated with 100 ng of PCNA. Increasing amounts of 50, His-68 (as a control), or BSA were then added (horizontal axis). Bound proteins to PCNA were recognized by an antibody against p50 or p68 to detect the interaction between PCNA and p50 or p68.</p

A model for the network of protein-protein interactions that may be involved in the assembly of the pol δ-PCNA complex.

<p><b>A:</b> Complete structure. The inter-subunit protein-protein contacts for both pol δ and PCNA are shown as solid lines. Interactions between pol δ subunits and PCNA subunits are shown by the tripled lines. PCNA is shown as having the ability to act as a trivalent molecule. <b>B and C:</b> The protein-protein interaction network for the p125/p50/p68 trimer (panel B) and for the p125/p50/p12 trimer (panel C). In such models, p50 provides an alternative interaction with one monomer of PCNA homotrimer retaining three trivalent interactions of PCNA monomers. <b>D:</b> The protein-protein interaction network for 125/p50. Only two PCNA monomers retain trivalent interactions.</p

Co-nuclear staining of p50 and PCNA.

<p>Hela cells were fixed, permeabilized, and co-stained for p50 and PCNA using indirect immunofluorescence in which an anti-p50 rabbit polyclonal antibody was used for p50 while an anti-PCNA mouse monoclonal antibody PC-10 was used for PCNA. <b>A:</b> Rhodamine-X-conjugated anti-rabbit IgG secondary antibody was used for p50 (red). <b>B:</b> Alexafluor488-conjugated anti-mouse IgG secondary antibody was used for PCNA (green). <b>C:</b> DNA was counterstained with DAPI immunofluorescence (blue). <b>D:</b> Merger for p50 (panel A) and DAPI (panel C). <b>E:</b> Merger for p50 (panel A) and PCNA (panel B). <b>F:</b> Merger for p50 (panel A), PCNA (panel B), and DAPI (panel C). Cells were analyzed and photographed with an Axiovert 200 M fluorescence microscope (Zeiss).</p

Analysis for the production of polyclonal antibody.

<p><b>A:</b> Coomassie Blue stained SDS-PAGE analysis for the purification of polyclonal antibody against p50 after affinity chromatography on a 5-ml Protein A/G Plus column. The dialyzed sample in PBS after ammonium sulfate precipitation (Bc), flow-through (Ft), wash (W₁ and W₂), and eluted fractions were analyzed on 12% SDS-PAGE followed by Coomassie Blue staining. Protein marker in kDa is indicated by “M”. The heavy and light chains are marked by arrows. <b>B:</b> Measurement of sensitivity and specificity of purified antibody by Western blotting with Hela cell extracts. The six lanes show decreasing concentrations of antibody contained 0.8, 0.4, 0.2, 0.1, 0.05 (lane 2-6), and 0 µg/ml (lane 1) of antibody/slice membrane, respectively. The detected endogenous p50 is marked by an arrow.</p

MALDI spectra of tryptic digestion of recombinant p50 subunit of human DNA pol δ.

<p>The identified protein, score, amino acid sequence coverage and the number of identified peptides are shown. The sequences of identified peptides shown in bold red covered 34% sequences against the deduced amino acid sequence of p50.</p