Integrins are a large family of heterodimeric cell adhesion molecules composed of α and β subunits. Through interaction with their specific ligands, integrins mediate cell-cell and cell-extracellular matrix interactions. Via outside-in signaling, integrins can recruit cytoplasmic proteins to their intracellular domains and then cluster into supramolecular structures and trigger downstream signaling. Integrin activation is associated with a global conformation rearrangement from bent to extended in ectodomains and the separation of α and β subunit cytoplasmic domains. During cell migration, integrins regulate the focal adhesion dynamics and transmit forces between the extracellular matrix and the cell cytoskeleton. In tumor microenvironment, integrins on multiple kinds of cells could be activated, which modulates cell migration into tumor and contributes to angiogenesis and tumor metastasis. Here, we review the mechanism of integrin activation, dynamics of focal adhesions during cell migration and tumor metastasis.
Cell Adhesion ; Cell Adhesion Molecules ; Focal Adhesions ; Integrins ; Signal Transduction

Despite increased evidence of bio-activity following far-infrared (FIR) radiation, susceptibility of cell signaling to FIR radiation-induced homeostasis is poorly understood. To observe the effects of FIR radiation, FIR-radiated materials-coated fabric was put on experimental rats or applied to L6 cells, and microarray analysis, quantitative real-time polymerase chain reaction, and wound healing assays were performed. Microarray analysis revealed that messenger RNA expressions of rat muscle were stimulated by FIR radiation in a dose-dependent manner in amount of 10% and 30% materials-coated. In 30% group, 1,473 differentially expressed genes were identified (fold change [FC] > 1.5), and 218 genes were significantly regulated (FC > 1.5 and p < 0.05). Microarray analysis showed that extracellular matrix (ECM)-receptor interaction, focal adhesion, and cell migration-related pathways were significantly stimulated in rat muscle. ECM and platelet-derived growth factor (PDGF)-mediated cell migration-related genes were increased. And, results showed that the relative gene expression of actin beta was increased. FIR radiation also stimulated actin subunit and actin-related genes. We observed that wound healing was certainly promoted by FIR radiation over 48 h in L6 cells. Therefore, we suggest that FIR radiation can penetrate the body and stimulate PDGF-mediated cell migration through ECM-integrin signaling in rats.
Actins ; Animals ; Cell Movement* ; Extracellular Matrix ; Focal Adhesions ; Gene Expression ; Homeostasis ; Infrared Rays ; Integrins ; Microarray Analysis ; Muscle, Skeletal* ; Platelet-Derived Growth Factor* ; Rats ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Wound Healing

The biophysical properties of the extracellular matrix (ECM) dictate tissue-specific cell behaviour. In the skeleton system, bone shows the potential to adapt its architecture and contexture to environmental rigidity via the bone remodelling process, which involves chondrocytes, osteoblasts, osteoclasts, osteocytes and even peripheral bone marrow-derived stem/stromal cells (BMSCs). In the current study, we generated stiff (~1 014 ± 56) kPa, Young's modulus) and soft (~46 ± 11) kPa silicon-based elastomer polydimethylsiloxane (PDMS) substrates by mixing curing agent into oligomeric base at 1:5 and 1:45 ratios, respectively, and investigated the influence of substrate stiffness on the cell behaviours by characterizing cell spreading area, cell cytoskeleton and cell adhesion capacity. The results showed that the cell spreading areas of chondrocytes, osteoblasts, osteoclasts, osteocytes and BMSCs were all reduced in the soft substrate relative to those in the stiff substrate. F-actin staining confirmed that the cytoskeleton was also changed in the soft group compared to that in the stiff group. Vinculin in focal adhesion plaques was significantly decreased in response to soft substrate compared to stiff substrate. This study establishes the potential correlation between microenvironmental mechanics and the skeletal system, and the results regarding changes in cell spreading area, cytoskeleton and cell adhesion further indicate the important role of biomechanics in the cell-matrix interaction.
Actins ; Cell Adhesion ; Elastic Modulus ; Focal Adhesions ; physiology ; Humans ; Vinculin ; analysis ; metabolism

PURPOSE: This study was conducted to verify the induction and mechanism of selective apoptosis in G361 melanoma cells using anti-HER2 antibody-conjugated gold nanoparticles (GNP-HER2). MATERIALS AND METHODS: Following GNP-HER2 treatment of G361 cells, cell cycle arrest and apoptosis were measured by WST-1 assay, Hemacolor staining, Hoechst staining, immunofluorescence staining, fluorescence-activated cell sorting analysis, and Western blotting.
Actins ; Apoptosis Inducing Factor ; Apoptosis ; Blotting, Western ; Caspase 3 ; Caspases ; Cell Adhesion ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Death ; Cyclin A ; Cyclin D1 ; Cyclin E ; Cyclins ; Cytochromes c ; Cytoplasm ; DNA Fragmentation ; Down-Regulation ; Flow Cytometry ; Fluorescent Antibody Technique ; Focal Adhesions ; Melanoma ; Mitochondria ; Nanoparticles ; Phosphotransferases ; Receptor, Epidermal Growth Factor ; Up-Regulation

BACKGROUND: Actinic keratosis (AK) was an intraepidermal tumor which caused by ultraviolet irradiation-induced skin damage. OBJECTIVE: The aim was to screen biomarkers for development of skin disease by comparing the gene expression profiles between cutaneous squamous cell carcinoma (CSCC) and AK. METHODS: GSE45216 with 30 cutaneous squamous cell carcinoma patients and 10 actinic keratosis patients were downloaded and significance analysis of microarrays was processed to screen differently expressed genes (DEGs). Fisher's exact test was processed for DEGs enrichment. Pathway relationship network systematically reflected the signal conduction and synergism between enriched pathways based on Kyoto Encyclopedia of Genes and Genomes database. Gene co-expression network was constructed according to gene expression data. Quantitative real-time-PCR was used to verify screened biomarkers. RESULTS: Total 410 DEGs were screened and enriched into various functions, such as signal transduction and negative regulation of apoptotic process. They also participated into cytokine-cytokine receptor interaction and focal adhesion. The pathway relationship network was constructed with 27 nodes. Hub nodes with higher degree of this network were mitogen-activated protein kinase signaling pathway and apoptosis. The gene co-expression network was constructed with 39 nodes. Thereinto, hub node was ELOVL fatty acid elongase. The expression levels of ELOVL4 and HPGD were significantly higher in CSCC samples than that in AK samples, while the expression levels of INHBA and LAMC2 in CSCC samples were significantly lower than that in AK samples. CONCLUSION: These screened genes, including ELOVL4, HPGD, INHBA and LAMC2, played important roles in transformation from AK to CSCC.
Actins* ; Apoptosis ; Biomarkers* ; Carcinoma, Squamous Cell* ; Diagnosis* ; Epithelial Cells* ; Focal Adhesions ; Gene Expression* ; Genome ; Humans ; Keratosis, Actinic* ; Mass Screening* ; Protein Kinases ; Signal Transduction ; Skin Diseases* ; Skin* ; Transcriptome

PURPOSE: To evaluate the postoperative outcome of the multiple slit on plaque plication technique for the treatment of Peyronie's disease. MATERIALS AND METHODS: We retrospectively evaluated 22 patients who underwent plaque incision with penile plication for the surgical treatment of Peyronie's disease, who had failed medical treatment between 2009 and 2014. Patients were grouped by preoperative degree of penile curvature into Group I: mild (n=5, 22.7%), Group II: moderate (n=11, 50.0%), and Group III: severe (n=6, 27.3%). After a thorough review of the medical records, we evaluated (a) the correction of the curvature; (b) sexual function; and (c) any penile shortening or other complications. RESULTS: The mean postoperative follow-up period was 39 months. Complete correction of the curvature was attained in 21 patients (95.5%). As an inevitable complication, minimal penile shortening (<1.5 cm) was reported by 14 patients (82.4%) but did not adversely affect sexual intercourse (0%), and all patients found the extent of penile shortening to be acceptable. Nineteen patients had good erectile function (International Index of Erectile Function >21). The most frequent complication was subcutaneous penile edema in three patients (13.6%), which was resolved within about 3 months following surgery. CONCLUSIONS: As a modified technique, multiple slit on plaque with plication is a simple, minimally-invasive and effective technique for correcting penile curvature regardless of curvature severity. The degree of penile curvature does not significantly predict the amount of penile length loss.
Coitus ; Edema ; Focal Adhesions ; Follow-Up Studies ; Humans ; Male ; Medical Records ; Penile Induration* ; Retrospective Studies

PURPOSE: To analyze the structural and morphological characteristics of retinal astrocytic hamartomas in tuberous sclerosis patients using fundus autofluorescence, fluorescein angiography and spectral-domain optical coherence tomography. CASE SUMMARY: Fundus examination, fundus autofluorescence, fluorescein angiography and spectral-domain optical coherence tomography were performed in three patients with tuberous sclerosis and the morphological and structural characteristics of retinal astrocytic hamartomas were analyzed. In the fundus autofluorescence, type 1 retinal astrocytic hamartoma showed hypofluorescence and type 3 showed central hyperfluorescence and surrounding hypofluorescence. Spectral domain optical coherence tomography showed dome-shaped hyper-reflectivity within the nerve fiber layer and focal adhesion of the vitreous cortex in the type 1 retinal astrocytic hamartoma. No abnormalities were observed in the outer retinal layer and retinal pigment epithelium. In the type 3 retinal astrocytic hamartoma, optical coherence tomography showed disorganization of retinal tissue and posterior shadowing. Intratumoral cavitation and moth-eaten appearance caused by intratumoral calcification were observed and the vitreous cortex adhered to the top of the tumor and showed traction. Retinal arterial sheathing was observed in all cases and hyper- reflectivity of the arterial wall was noted on optical coherence tomography. CONCLUSIONS: Fundus autofluorescence, fluorescein angiography and spectral-domain optical coherence tomography are helpful for the classification and diagnosis of retinal astrocytic hamartomas found in tuberous sclerosis patients as well as for differentiation from other lesions.
Classification ; Diagnosis ; Fluorescein Angiography* ; Fluorescein* ; Focal Adhesions ; Hamartoma* ; Humans ; Nerve Fibers ; Retinal Pigment Epithelium ; Retinaldehyde* ; Shadowing (Histology) ; Tomography, Optical Coherence* ; Traction ; Tuberous Sclerosis*

PURPOSE: To evaluate adherence of human gingival fibroblasts (HGFs) to transmucosal abutment of dental implant with different surface conditions with time and to investigate the roles of focal adhesion linker proteins (FALPs) involved in HGFs adhesion to abutment surfaces. MATERIALS AND METHODS: Morphologies of cultured HGFs on titanium and ceramic discs with different surface were observed by scanning electron microscopy. Biocompatibility and focal adhesion were evaluated by ultrasonic wave application and cell viability assay. FALPs expression levels were assessed by RT-PCR and western blot. RESULTS: There seemed to be little difference in biocompatibility and adhesion strength of HGFs depending on the surface conditions and materials. In all experimental groups, the number of cells remaining on the disc surface after ultrasonic wave application increased more than 2 times at 3 days after seeding compared to 1-day cultured cells and this continued until 7 days of culture. FALPs expression levels, especially of vinculin and paxillin, also increased in 5-day cultured cells compared to 1-day cultured fibroblasts on the disc surface. CONCLUSION: These results might suggest that the strength of adhesion of fibroblasts to transmucosal abutment surfaces increases with time and it seemed to be related to expressions of FALPs.
Cell Survival ; Cells, Cultured ; Ceramics ; Dental Implants ; Fibroblasts ; Focal Adhesions ; Humans ; Microscopy, Electron, Scanning ; Paxillin ; Proteins ; Seeds ; Titanium ; Ultrasonics ; Vinculin

Syntenin is an adaptor molecule containing 2 PDZ domains which mediate molecular interactions with diverse integral or cytoplasmic proteins. Most of the results on the biological function of syntenin were obtained from studies with malignant cells, necessitating exploration into the role of syntenin in normal cells. To understand its role in normal cells, we investigated expression and function of syntenin in human lymphoid tissue and cells in situ and in vitro. Syntenin expression was denser in the germinal center than in the extrafollicular area. Inside the germinal center, syntenin expression was obvious in follicular dendritic cells (FDCs). Flow cytometric analysis with isolated cells confirmed a weak expression of syntenin in T and B cells and a strong expression in FDCs. In FDC-like cells, HK cells, most syntenin proteins were found in the cytoplasm compared to weak expression in the nucleus. To study the function of syntenin in FDC, we examined its role in the focal adhesion of HK cells by depleting syntenin by siRNA technology. Knockdown of syntenin markedly impaired focal adhesion kinase phosphorylation in HK cells. These results suggest that syntenin may play an important role in normal physiology as well as in cancer pathology.
B-Lymphocytes ; Cytoplasm ; Dendritic Cells, Follicular* ; Focal Adhesion Protein-Tyrosine Kinases* ; Focal Adhesions* ; Germinal Center ; Humans* ; Lymphoid Tissue ; PDZ Domains ; Phosphorylation ; Proteins ; RNA, Small Interfering ; Syntenins*

Tumor angiogenesis induced by vascular endothelial cells (VECs) migration is a necessary condition for tumor growth and metastasis. The purpose of this study is to investigate the effect of focal adhesion kinase (FAK) inhibitor (50nmol/mL) on the adhesion and migration of endothelial cells(ECs) and the expression of focal adhesion proteins vinculin, talin and paxillin. Scratch wound migration assay was performed to examine the effect of FAK inhibitor with 50nmol/mL on ECs migration at 0, 5, 10, 30, 60 and 120min, respectively. And immunofluorescence analysis was performed to detect the expression of F-actin in ECs treated with FAK inhibitor within 2h. Western blot was carried out to determine the effect of FAK inhibitor on expression of vinculin, talin and paxillin proteins. The results showed that the migration distance and the expression of F-actin in ECs treated with FAK inhibitor decreased significantly compared with that of the controls, and the level of vinculin showed no significant difference with increasing of treated time of FAK inhibitor. However, the talin and paxillin showed an identical decreasing tendency in 5-10min, but slowly going up in 30min and then after subsequently decreasing. The results of this study proved that blocking phosphorylation of FAK could inhibit VECs adhesion and migration by downregulating focal adhesion proteins so that it may inhibit tumor angiogenesis. This may provide a new approach for tumor therapy.
Cell Adhesion ; Cell Movement ; physiology ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Focal Adhesion Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Focal Adhesions ; metabolism ; physiology ; Humans ; Neoplasms ; blood supply ; Neovascularization, Pathologic ; Paxillin ; metabolism ; Talin ; metabolism ; Vinculin ; metabolism