Adhesion Proteins Research Articles

Copper Ion-Inspired Dual Controllable Drug Release Hydrogels for Wound Management: Driven by Hydrogen Bonds.

Bacterial infections and inflammation progression yield huge trouble for the management of serious skin wounds and burns. However, some hydrogel dressing exhibit poor wound-healing capabilities. Additionally, little information is given on the molecular theory of hydrogel gelation mechanisms and drug release performance from drug-polymer network in the water environment. Herein, cationic guar gum (CG) is first mixed with dipotassium glycyrrhizinate (DG), and then crosslinked Cu2+ to strengthen the mechanical strength followed by encapsulating mussel adhesive protein (MAP) as composite dressings. Intriguingly, CG-Cu2+ 0.5-DG10 possessed proper rheological properties and mechanical strength predominantly driven by strong CG-H2O-Cu2+ and Cu2+-CG hydrogen bonding interaction. Weak DG-CG hydrogen bonding only controlled DG release in the initial 4 h, while strong hydrogen bonding is the main force regulating the sustained release of Cu2+ within 48 h. The incorporation of MAP further loosened the tight crosslinking of CG-Cu2+ 0.5-DG10. The screened CG-Cu2+ 0.5-DG10/MAP possessed excellent self-healing, injectability, antibacterial, anti-inflammatory, cell proliferation-promotion activities with high biocompatibility. Therefore, CG-Cu2+ 0.5-DG10/MAP hydrogel expedited wound closure on S. aureus-infected full-thickness skin wound model and lowered necrosis progression to the unburned interspaces on a rat burn model. The results highlight the promising translational potential of Cu2+-inspired hydrogels for the management of burns and infected wounds.

Effects of syndecan-4 silencing on the extracellular matrix remodeling in anoikis-resistant endothelial cells.

Anoikis is a process of programmed cell death induced by the loss of cell/matrix interactions. In previous work, we have shown that the acquisition of anoikis resistance upregulates syndecan-4 (SDC4) expression in endothelial cells. In addition, SDC4 gene silencing by microRNA interference reverses the transformed phenotype of anoikis-resistant endothelial cells. Due to this role of SDC4 in regulating the behavior of anoikis-resistant endothelial cells, we have evaluated that the functional consequences of SDC4 silencing in the extracellular matrix (ECM) remodeling in anoikis-resistant rabbit aortic endothelial cells submitted to SDC4 gene silencing (miR-Syn4-Adh-1-EC). For this, we evaluated the expression of adhesive proteins, ECM receptors, nonreceptor protein-tyrosine kinases, and ECM-degrading enzymes and their inhibitors. Altered cell behavior was monitored by adhesion, migration, and tube formation assays. We found that SDC4 silencing led to a decrease in migration and angiogenic capacity of anoikis-resistant endothelial cells; this was accompanied by an increase in adhesion to fibronectin. Furthermore, after SDC4 silencing, we observed an increase in the expression of fibronectin, collagen IV, and vitronectin, and a decrease in the expression of integrin α5β1 and αvβ3, besides that, silenced cells show an increase in Src and FAK expression. Quantitative polymerase chain reactionand Western blot analysis demonstrated that SDC4 silencing leads to altered gene and protein expression of MMP2, MMP9, and HSPE. Compared withparental cells, SDC4 silenced cells showed a decrease in nitric oxide production and eNOS expression. In conclusion, these data demonstrate that SDC4 plays an important role in ECM remodeling. In addition, our findings represent an important step towardunderstanding the mechanism by which SDC4 can reverse the transformed phenotype of anoikis-resistant endothelial cells.

Mussel-Inspired Self-Adhesive and Tough Hydrogels for Effectively Cooling Solar Cells and Thermoelectric Generators.

Adhesive hydrogel-based evaporative cooling, which necessitates no electricity input, holds promise for reducing energy consumption in thermal management. Herein, inspired by the surface attachment of mussel adhesive proteins via abundant dynamic covalent bonds and noncovalent interactions, we propose a facile strategy to fabricate a self-adhesive cooling hydrogel (Li-AA-TA-PAM) using a copolymer of acrylamide (AM) and acrylic acid (AA) as the primary framework. The monomers formed hydrogen bonds between their carboxyl and amide groups, while tannic acid (TA), rich in catechol groups, enhances the adhesion of the hydrogel through hydrogen bonding. The hydrogel demonstrated strong adhesion to various material surfaces, including plastic, ceramic, glass, and metal. Even under high-speed rotation, it still maintains robust adhesion. The adhesion strength of the Li-AA-TA-PAM hydrogel to aluminum foil reached an impressive value of 296.875 kPa. Interestingly, the excellent contact caused by robust adhesion accelerates heat transfer, resulting in a rapid cooling performance, which mimics the perspiration of mammals. Lithium bromide (LiBr) with hydroactively sorptive sites is introduced to enhance sorption kinetics, thereby extending the effective cooling period. Consequently, the operation temperature of commercial polycrystalline silicon solar cells was reduced by 16 °C under an illumination of 1 kW m-2, and the corresponding efficiency of energy conversion was increased by 1.14%, thereby enhancing the output properties and life span of solar cells. The strategy demonstrates the potential for refrigeration applications using viscous gels.

ETS1, a Target Gene of the EWSR1::FLI1 Fusion Oncoprotein, Regulates the Expression of the Focal Adhesion Protein TENSIN3.

The mechanistic basis for the metastasis of Ewing sarcomas remains poorly understood, as these tumors harbor few mutations beyond the chromosomal translocation that initiates the disease. Instead, the epigenome of Ewing sarcoma cells reflects the regulatory state of genes associated with the DNA-binding activity of the fusion oncoproteins EWSR1::FLI1 or EWSR1::ERG. In this study, we examined the EWSR1::FLI1/ERG's repression of transcription factor genes, concentrating on those that exhibit a broader range of expression in tumors than in Ewing sarcoma cell lines. Focusing on one of these target genes, ETS1, we detected EWSR1::FLI1 binding and an H3K27me3-repressive mark at this locus. Depletion of EWSR1::FLI1 results in ETS1's binding of promoter regions, substantially altering the transcriptome of Ewing sarcoma cells, including the upregulation of the gene encoding TENSIN3 (TNS3), a focal adhesion protein. Ewing sarcoma cell lines expressing ETS1 (CRISPRa) exhibited increased TNS3 expression and enhanced movement compared with control cells. Visualization of control Ewing sarcoma cells showed a distributed vinculin signal and a network-like organization of F-actin; in contrast, ETS1-activated Ewing sarcoma cells showed an accumulation of vinculin and F-actin toward the plasma membrane. Interestingly, the phenotype of ETS1-activated Ewing sarcoma cell lines depleted of TNS3 resembled the phenotype of the control cells. Critically, these findings have clinical relevance as TNS3 expression in Ewing sarcoma tumors positively correlates with that of ETS1. Implications: ETS1's transcriptional regulation of the gene encoding the focal adhesion protein TENSIN3 in Ewing sarcoma cells promotes cell movement, a critical step in the evolution of metastasis.

Abstract SY34-01: Plasticity, dormancy, and glycosylation of circulating tumor cell clusters in response to therapy

Abstract Cellular plasticity and stemness properties enable dynamic changes of circulating tumor cells (CTCs) during cancer dissemination, such as aggregation or cohesion of single CTCs into multicellular CTC clusters with 20-100 times higher metastatic propensity than the singles. Our work demonstrated that stemness glycoproteins on breast cancer stem cells, such as CD44, CD81, and ICAM1 drive CTC aggregation in metastatic breast cancer, such as triple negative breast cancer (TNBC). To determine the glycosylation patterns in CTCs and its association with clinical outcomes, we established multiple CTC analysis approaches including CellSearch, flow cytometry, and immunohistochemistry using patient blood and tissue sections collected at the pre-treatment baseline and after-therapy timepoints. We found that chemotherapy-evasive CTC clusters are relatively quiescent with a specific loss of terminal sugar residues α2,6-sialic acids in glycoproteins. CTCs showed dynamic hypo-sialylation in the blood with loss of the sialyl-transferase ST6GAL1, promoting CTC cluster formation with cellular quiescence (proliferative dormancy) and evading chemotherapy in breast cancer. Seeded tumor cells regained ST6GAL1 to enable metastatic colonization. Many adhesion proteins and stemness drivers as glycoprotein substrates of ST6GAL1 drive CTC clustering and metastatic seeding. Neutralizing antibodies against these clustering drivers inhibit CTC cluster formation and improve therapy response, thereby blocking lung metastasis in TNBC. Citation Format: Huiping Liu. Plasticity, dormancy, and glycosylation of circulating tumor cell clusters in response to therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr SY34-01.

Inactivation of kindlin-3 increases human melanoma aggressiveness through the collagen-activated tyrosine kinase receptor DDR1.

The role of the focal adhesion protein kindlin-3 as a tumor suppressor and its interaction mechanisms with extracellular matrix constitute a major field of investigation to better decipher tumor progression. Besides the well-described role of kindlin-3 in integrin activation, evidence regarding modulatory functions between melanoma cells and tumor microenvironment are lacking and data are needed to understand mechanisms driven by kindlin-3 inactivation. Here, we show that kindlin-3 inactivation through knockdown or somatic mutations increases BRAFV600mut melanoma cells oncogenic properties via collagen-related signaling by decreasing cell adhesion and enhancing proliferation and migration in vitro, and by promoting tumor growth in mice. Mechanistic analysis reveals that kindlin-3 interacts with the collagen-activated tyrosine kinase receptor DDR1 (Discoidin domain receptor 1) modulating its expression and its interaction with β1-integrin. Kindlin-3 knockdown or mutational inactivation disrupt DDR1/β1-integrin complex in vitro and in vivo and its loss improves the anti-proliferative effect of DDR1 inhibition. In agreement, kindlin-3 downregulation is associated with DDR1 over-expression in situ and linked to worse melanoma prognosis. Our study reveals a unique mechanism of action of kindlin-3 in the regulation of tumorigenesis mediated by the collagen-activated tyrosine kinase receptor DDR1 thus paving the way for innovative therapeutic targeting approaches in melanoma.

Neuroligin-2 shapes individual slow waves during slow-wave sleep and the response to sleep deprivation in mice

BackgroundSleep disturbances are a common comorbidity to most neurodevelopmental disorders and tend to worsen disease symptomatology. It is thus crucial to understand mechanisms underlying sleep disturbances to improve patients’ quality of life. Neuroligin-2 (NLGN2) is a synaptic adhesion protein regulating GABAergic transmission. It has been linked to autism spectrum disorders and schizophrenia in humans, and deregulations of its expression were shown to cause epileptic-like hypersynchronized cerebral activity in rodents. Importantly, the absence of Nlgn2 (knockout: KO) was previously shown to alter sleep-wake duration and quality in mice, notably increasing slow-wave sleep (SWS) delta activity (1–4 Hz) and altering its 24-h dynamics. This type of brain oscillation is involved in memory consolidation, and is also a marker of homeostatic sleep pressure. Sleep deprivation (SD) is notably known to impair cognition and the physiological response to sleep loss involves GABAergic transmission.MethodsUsing electrocorticographic (ECoG) recordings, we here first aimed to verify how individual slow wave (SW; 0.5-4 Hz) density and properties (e.g., amplitude, slope, frequency) contribute to the higher SWS delta activity and altered 24-h dynamics observed in Nlgn2 KO mice. We further investigated the response of these animals to SD. Finally, we tested whether sleep loss affects the gene expression of Nlgn2 and related GABAergic transcripts in the cerebral cortex of wild-type mice using RNA sequencing.ResultsOur results show that Nlgn2 KO mice have both greater SW amplitude and density, and that SW density is the main property contributing to the altered 24-h dynamics. We also found the absence of Nlgn2 to accelerate paradoxical sleep recovery following SD, together with profound alterations in ECoG activity across vigilance states. Sleep loss, however, did not modify the 24-h distribution of the hypersynchronized ECoG events observed in these mice. Finally, RNA sequencing confirmed an overall decrease in cortical expression of Nlgn2 and related GABAergic transcripts following SD in wild-type mice.ConclusionsThis work brings further insight into potential mechanisms of sleep duration and quality deregulation in neurodevelopmental disorders, notably involving NLGN2 and GABAergic neurotransmission.

Environmental concentrations of acetaminophen and its metabolites promote the spread of antibiotic resistance genes through pheromone signaling pathway

The massive use of acetaminophen (APAP), an antipyretic and analgesic drug, especially during the COVID-19 pandemic, has caused the environmental residue and pollution of acetaminophen and its metabolites. However, the environmental ecological and health issues they may cause are still unclear. In this study, we found that environmental concentrations of APAP and its metabolites could promote the conjugative transfer of antibiotic resistance genes mediated by plasmid pCF10 through pheromone-like effect rather than the commonly mechanism found in current studies. Conjugative transfer studies showed that APAP and its metabolites increased the frequency of conjugative transfer of ARGs by up to 3.3 times, reaching 3.2 × 10-2. We explored the underling mechanisms using qPCR, western blot, and SEM images. This study demonstrates that APAP stimulates pheromone secretion, subsequently triggering conjugation and accelerating downstream gene expression. Furthermore, APAP functions as a pheromone, initially facilitating plasmid cleavage and peptidoglycan hydrolysis, followed by the promotion of adhesion protein PrgB expression and T4SS scaffold construction, ultimately enhancing DNA strand transfer via T4CP. This study provides a theoretical basis for understanding the environmental hazards of APAP and the environmental sustainability.

Evaluation of poly(2-hydroxyethyl methacrylate) and poly(N-hydroxyethyl acrylamide) cryogels as potential quercetin release matrices

Fabrication of a suitable drug delivery system forms an attractive strategy to overcome the low bioavailability of quercetin. Poly(2-hydroxyethyl methacrylate–co-N-hydroxyethyl acrylamide), P(HEMA-co-HEAA) copolymer samples, and homopolymers of 2-hydroxyethyl methacrylate (PHEMA) and N-hydroxyethyl acrylamide (PHEAA) offer potential as quercetin delivery matrices owing to their favorable properties rendered in this study. Free radical polymerization applied under cryogenic conditions produced the polymer gels. The homopolymers and copolymers are noncytotoxic, porous, soft cryogels with surfaces resistant to protein and HCT-116 cancer cell adhesion. In vitro, quercetin release studies from samples reveal swelling-controlled, zero-order drug release at pH = 7.4 and 37 °C with high cumulative release percentages ranging from 92.03% to 94.82%. The durability of the cryogels and limited quercetin release at pH = 2.0 indicate that these cryogels are promising matrices for successfully delivering quercetin to the small intestine, where its primary absorption occurs.

Development of soybean meal-based adhesive with multiple functions via a dual cross-linked tailoring-making strategy

As a renewable biomass resource, soy protein adhesives are a potential alternative to petroleum-based ones. However, synthesizing soy protein adhesives with excellent performance via a low-cost and facile strategy for practical application in the wood industry remains challenging. Herein, an innovative approach for fabricating a strong, tough, low-cost soy protein adhesive via dual cross-linked tailoring-making technology was proposed to impart multiple excellent performances. Specifically, the new strategy involved using calcium lignosulfonate (CLS), a residue from the pulping industry, as an anionic surfactant to untwist the spherical structure of soy protein, stretch the protein chains, and knit a reversible dynamic network structure with the protein chains and soybean polysaccharide molecules by multiple non-covalent interactions, and synergize with the robust cross-linked network of 1,6-hexanediol diglycidyl ether (HDE) to tailor the adhesive structure system. Notably, this design reflects the vital role of remolding the protein structural and soybean polysaccharide molecules network in optimizing the adhesive properties, including excellent bonding strength, anti-mildew, and flame retardancy performances. Therefore, this facile strategy can be explored to develop green and renewable protein adhesives for industrial wood applications.

Lignin reinforced tough, adhesive and recoverable protein organohydrogels for wearable strain sensing under sub-zero temperatures

Protein-based hydrogels with promising biocompatibility and biodegradability have attracted considerable interest in areas of epidermal sensing, whereas, which are still difficult to synchronously possess high mechanical strength, self-adhesion, and recoverability. Hence, the bio-polymer lignosulfonate-reinforced gluten organohydrogels (GOHLx) are fabricated through green and simple food-making processes and the following solvent exchange with glycerol/water binary solution. Ascribing to the uniform distribution of lignosulfonate in gluten networks, as well as the noncovalent interactions (e.g., H-bond) between them, the resultant GOHLx exhibit favorable conductivity (~14.3 × 10−4 S m−1), toughness (~711.0 kJ m−3), self-adhesion (a maximal lap-shear strength of ~33.5 kPa), high sensitivity (GF up to ~3.04) and durability (~3000 cycles) toward shape deformation, which are suitable for the detection of both drastic (e.g., elbow and wrist bending) and subtle (e.g., swallowing and speaking) human movements even under −20 °C. Furthermore, the GOHLx is also biocompatible, degradable, and recoverable (by a simple kneading process). Thus, this work may pave a simple, green and cheap way to prepare all-biomass-based, tough, sticky, and recoverable protein-based organohydrogels for epidermal strain sensing even in harsh environments.

Camellia meal-based adhesive with synergistic crosslinking of physical and chemical interaction for preparing aldehyde-free, anti-mildew, water-resistant wood-based composites

Wood adhesives containing toxic aldehyde-based adhesives play a vital role in the performance of wood-based panels, while the mechanical properties and water and mildew resistance of aldehyde-free adhesives are lacking. In this study, a high-strength aldehyde-free adhesive was constructed via a combination of physical and chemical crosslinks. Inexpensive alum was used to ensure a high degree of crosslinking and to increase the crystallinity. Metal ions in alum opened the protein helix, exposed the active groups, increased the number of hydrogen bonds, and ultimately improved the internal physical crosslinking ability of the adhesive. The compound formed by the Schiff base reaction formed coordination bonds with metal ions, thus forming a covalently-crosslinked network. The high-strength polymer produced in this study contained multiple physical and covalent crosslinks, resulting in significantly improved mechanical properties of the adhesive. Its water-resistant adhesive strength reached 1.96 MPa, which was 180.2% higher than that of ordinary phytogenic protein adhesive (0.69 MPa), and it can still reach 1.28 MPa after hot water circulation soaking experiment. The adhesive also possessed antifungal properties and flame-retardant capabilities, achieving a V-1 rating in the UL-94 test. This strategy expanded the application of phytogenic protein adhesives in environmentally friendly wood composite materials by replacing synthetic resins that released formaldehyde and provided an economical and feasible industrial scale production method for the preparation of high strength, water, and mildew resistant, flame retardant indoor and outdoor wood-based panels.

A simple and efficient strategy for preparing anticoagulant coatings on biomedical polyurethane surfaces through a fluorinated urethane prepolymer

Developing an efficient yet uncomplicated method to achieve anticoagulant coatings on biomedical PU surfaces remains a challenge. In this research, we have proposed a very simple way to synthesize fluorinated urethane prepolymers (FPUs) that possess extended fluorocarbon side chains and terminal groups, innovatively using a new fluorinated chain extender and a fluorinated terminal capping agent. These FPUs have been utilized as additives to fabricate biomedical PU blends (BPUB). Incorporating a minimal quantity of FPUs, as little as 2.5 %, bestows BPUB with exceptional capabilities to resist protein and platelet adhesion, which can further prevent platelet activation, facilitated by the self-migrating nature of the fluorocarbon chains toward the film's upper surfaces, as substantiated by contact angle measurements and XPS. DSC and TG analysis indicate that the addition of FPUs marginally affects the thermal stability of the BPUB films, yet it reduces the glass transition temperature of the PUs. Remarkably, the BPUB films demonstrate enhanced degradation resistance to physiological solutions, exhibit excellent hemocompatibility, and maintain extremely low cytotoxicity levels. Thus, the FPUs present themselves as highly encouraging candidates for the development of anticoagulant coatings on biomedical polymers.

Preparation of a superior soy protein adhesive with high solid content by enzymatic hydrolysis combined with cross-linking modification

The production of traditional wood adhesives relies on petrochemical resources and puts enormous pressure on the ecosystem. Therefore, it is important to use bio-based soy protein adhesives to replace traditional adhesives. However, soy protein adhesives have the problems of low solid content, high viscosity and poor water resistance. In this study, we combined enzymatic hydrolysis with cross-linking modification to reduce the molecular mass of soy protein and increase the solid content of adhesive, constructed a uniform and tight covalent bond cross-linking network in the adhesive. Through this modification strategy, we prepared a soy protein adhesive with high solid content, suitable viscosity and excellent bonding strength. The results showed that compared with 0-SPI adhesive, the viscosity of 4-SPI-18/PA/TA adhesive decreased by 61.6%, reached 21899 mPa·s. Meanwhile, the residual rate of the adhesive increased by 18% (59%), the moisture absorption rate reduced by 7.8% to reach 3.8%. The dry/wet shear strength of modified adhesive increased by 56.1% (1.28 MPa) and 44.3% (0.88 MPa), respectively, and the tensile strain at break increased by 58.1% (14.84%). This is because enzymolysis improved its coating performance, and formed mechanical interlocking with wood. In addition, the amount of SPI increased, and more protein molecules participated in the cross-linking reaction, forming a more uniform and compact cross-linking network structure in the adhesive, effectively improving the bonding strength and toughness. This study provides a novel approach for the preparation of cleaning and tenacious adhesives, aiming to explore a green development model.

Study of Hydration Repulsion of Zwitterionic Polymer Brushes Resistant to Protein Adhesion through Molecular Simulations.

The fabrication of antifouling zwitterionic polymer brushes represents a leading approach to mitigate nonspecific adhesion on the surfaces of medical devices. This investigation seeks to elucidate the correlation between the material composition and structural attributes of these polymer brushes in preventing protein adhesion. To achieve this goal, we modeled three different zwitterionic brushes, namely, carboxybetaine methacrylate (CBMA), sulfobetaine methacrylate (SBMA), and (2-(methacryloyloxy)ethyl)-phosphorylcholine (MPC). The simulations revealed that elevating the grafting density enhances the structural stability, hydration strength, and resistance to protein adhesion exhibited by the polymer brushes. PCBMA manifests a more robust hydration layer, while PMPC demonstrates the slightest interaction with proteins. In a comprehensive evaluation, PSBMA polymer brushes emerged as the best choice with superior stability, enhanced protein repulsion, and minimally induced protein deformation, resulting in effective resistance to nonspecific adhesion. The high-density SBMA polymer brushes significantly reduce the level of protein adhesion in AFM testing. In addition, we have pioneered the quantitative characterization of hydration repulsion in polymer brushes by analyzing the hydration repulsion characteristics at different materials and graft densities. In summary, our study provides a nuanced understanding of the material and structural determinants influencing the capacity of zwitterionic polymer brushes to thwart protein adhesion. Additionally, it presents a quantitative elucidation of hydration repulsion, contributing to the advancement and application of antifouling polymer brushes.

Selected markers of ovarian cancer and their relation to targeted therapy (Review).

Despite advances in surgical treatment techniques and chemotherapy-including anti-angiogenic and immune poly (ADP-ribose) polymerase inhibitors, the 5-year survival rate in ovarian cancer (OC) remains low. The reasons for this are the diagnosis of cancer in advanced clinical stages, chemoresistance and cancer recurrence. New therapeutic approaches are being developed, including the search for new biomarkers that are also targets for targeted therapy. The present review describes new molecular markers with relevance to targeted therapy, which to date have been studied only in experimental research. These include the angiogenic protein angiopoietin-2, the transmembrane glycoprotein ectonucleotide pyrophosphatase/phosphodiesterase 1, the adhesion protein E-cadherin, the TIMP metallopeptidase inhibitor 1 and Kruppel-like factor 7. Drugs affecting cancer stem cells (CSCs) in OC, such as metformin and salinomycin, as well as inhibitors of CSCs markers aldehyde dehydrogenase 1 (with the drug ATRA) and the transcription factor Nanog homeobox (microRNA) are also discussed. A new approach to prevention and possible therapies under investigation such as development of vaccines containing a subpopulation of CD117(+) and CD44(+) stem cells with a promising option for use in women with OC was described.

The suppression of cell motility through the reduction of FAK activity and expression of cell adhesion proteins by hAMSCs secretome in MDA-MB-231 breast cancer cells.

Breast cancer is a leading cause of death in women worldwide. Cancer therapy based on stem cells is considered as a novel and promising platform. In the present study, we explore the therapeutic effects of human amniotic mesenchymal stromal cells (hAMSCs) through the reduction of focal adhesion kinase (FAK) activity, SHP-2, and cell adhesion proteins such as Paxillin, Vinculin, Fibronectin, Talin, and integrin αvβ3 expression in MDA-MB-231 breast cancer cells. For this purpose, we employed a co-culture system using 6-well plate transwell. After 72h, hAMSCs-treated MDA-MB-231 breast cancer cells, the activity of focal adhesion kinase (FAK) and the expression of SHP-2 and cell adhesion proteins such as Paxillin, Vinculin, Fibronectin, Talin, and integrin αvβ3 expression were analyzed using western blot. The shape and migration of cells were also analyzed. Based on our results, a significant reduction in tumor cell motility through downregulation of the tyrosine phosphorylation level of FAK (at Y397 and Y576/577 sites) and cell adhesion expression in MDA-MB-231 breast cancer cells was demonstrated. Our findings indicate that hAMSCS secretome has therapeutic effects on cancer cell migration through downregulation of FAK activity and expression of cell adhesion proteins.

Surface modification affects human gingival epithelial cell behavior on polyetheretherketone surfaces.

Gingival epithelial attachment to the abutment is important for the prevention of peri-implantitis. Polyetheretherketone (PEEK) has recently gained attention as an alternative material to titanium; however, it is biologically inert, which is disadvantageous for obtaining soft tissue sealing of the transmucosal part of the implant abutment. Therefore, ultraviolet (UV) irradiation, argon plasma irradiation, and buffing were selected as treatments to modify the PEEK surface. None of the treatments had any effect on the material's mechanical strength. The UV and plasma treatments did not significantly affect the surface morphology. Surface elemental analysis showed a decrease in carbon content and an increase in oxygen content and wettability for all treatments. Human gingival epithelial cell adhesion, proliferation, and the expression of adhesion proteins integrin β4 and laminin 332, were increased. Surface modification to PEEK was suggested to enhance cell activity on PEEK.

Active osseointegration in an ex vivo porcine bone model.

Achieving osseointegration is a fundamental requirement for many orthopaedic, oral, and craniofacial implants. Osseointegration typically takes three to 6months, during which time implants are at risk of loosening. The aim of this study was to investigate whether osseointegration could be actively enhanced by delivering controllable electromechanical stimuli to the periprosthetic bone. First, the osteoconductivity of the implant surface was confirmed using an in vitro culture with murine preosteoblasts. The effects of active treatment on osseointegration were then investigated in a 21-day ex vivo model with freshly harvested cancellous bone cylinders (n = 24; Ø10 mm × 5mm) from distal porcine femora, with comparisons to specimens treated by a distant ultrasound source and static controls. Cell viability, proliferation and distribution was evident throughout culture. Superior ongrowth of tissue onto the titanium discs during culture was observed in the actively stimulated specimens, with evidence of ten-times increased mineralisation after 7 and 14days of culture (p < 0.05) and 2.5 times increased expression of osteopontin (p < 0.005), an adhesive protein, at 21days. Moreover, histological analyses revealed increased bone remodelling at the implant-bone interface in the actively stimulated specimens compared to the passive controls. Active osseointegration is an exciting new approach for accelerating bone growth into and around implants.

Abstract 4121: Unveiling discordant views of a novel drug's influence on cell motility from proteomics and immunofluorescence perspectives

Abstract Introduction: Metastasis is a leading cause of death in patients with solid tumors. Our group has discovered KBU2046, a selective inhibitor of cell motility (Nature Communications 2018). We conducted a time-course immunofluorescent staining to investigate the impact of KBU2046 on the cell adhesion and motility components of human prostate cancer cells. Our objective was to compare our findings with our proteomic analysis results in order to gain insights into the novel molecular mechanisms of KBU2046 in modulating cell motility. Experimental Procedures: Proteomics analysis. We treated PC3 cells with KBU2046 or vehicle (N=3/group) and quantified protein expression using Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS). In separate experiments (N=4), we performed LC-MS/MS after Tandem Mass Tag (TMT) labeling on isolated membrane fractions. We used bioinformatics tools, including Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Ingenuity Pathway Analysis (IPA), and protein-protein interaction (PPI) network analysis, to characterize significantly differentially expressed proteins upon KBU2046 treatment and tried to verify by Western blots. Immunofluorescence (IF) staining. Following treatment of PC3, 1532CPTX, and 1532NPTX cells with KBU2046 or vehicle at various intervals, cells were stained for β1, β5 integrin, actin, and DAPI. Images were acquired by a Zeiss LSM 800 Confocal Laser Scanning Microscope. Results: The proteomics analysis demonstrated that KBU2046 was having a major impact on cell motility processes, consistent with our prior functional studies. Despite conducting Western blot analysis, we could not confirm the candidate proteins linked to cell adhesion. Using IF, we examined changes in cell adhesion proteins over time in response to KBU2046 treatment. The time-course IF investigation revealed that KBU2046 affects adhesion proteins kinetically by altering their subcellular localization over time rather than altering their total expression level. This finding corroborates KBU2046's known effects on cell motility, demonstrating that a kinetic-based analysis yields important new information not directly represented in a single time point screen, although functionally related. Conclusions: Our study underscores the importance of integrating proteomic and imaging methodologies to procure a holistic comprehension of the molecular mechanisms that govern cell behavior, especially those that relate to highly dynamic processes. Through these methodologies, we have obtained a more profound understanding of how cells regulate motility and how that process can be therapeutically modulated. Citation Format: Weining Chen, Nicholas Woods, Henry Chun Hin Law, Fangfang Qiao, Sankarasubramanian Jagadesan, Chittibabu Guda, Raymond Bergan. Unveiling discordant views of a novel drug's influence on cell motility from proteomics and immunofluorescence perspectives [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4121.