Due to the good tumor-targeting and excellent biocompatibility, the drug-loading nanoparticles (NPs) has been widely applied in the diagnosis and treatment of cancer. However, after the NPs are recognized and internalized by cancer cells, the effects of NPs on cell migration behavior were unclear. In the present study, the self-assembly techniques (SAMs) was used to modify gold (Au) nanoparticles (Au NPs) with different chemical functional groups (CH3, OH, COOH and NH2) as model NPs. The dispersion of these groups in solution and the distribution in cells were studied by transmission electron microscope (TEM), respectively, and the proliferation was examined by MTT assay in vitro. The wound-healing and the Transwell assay were used to examine the effect of internalized Au-NPs on HepG2 cells migration. The results showed that different Au-NPs mainly distributed at the edge of the vesicle membrane and the gap between cells. The Au-NPs resulted in decreased cell viability in a concentration-depended manner. In addition, the results of wound-healing and Transwells assay indicated that the internalization of the NH2-NPs and OH-NPs would inhibit cell migration compared with those in the control group.
Carcinoma, Hepatocellular ; metabolism ; Cell Movement ; Cell Proliferation ; Cell Survival ; Gold ; Hep G2 Cells ; Humans ; Liver Neoplasms ; metabolism ; Metal Nanoparticles ; chemistry

This paper is aimed to investigate the effect of fluid shear stress on the tight junction of laryngeal squamous carcinoma (Hep2) cells and to explore the potential molecular mechanism. Hep2 cells were selected and subjected to the fluid shear stress of 1.4 dyn/cm2 for different time, respectively. The morphological changes of Hep2 cells under shear stress were observed using inverted microscope. The cell-cell junctions were examined by transmission electron microscope (TEM). The expressions of tight junction proteins (including Occludin, Claudin-5 and ZO-1) and the distribution of Claudin-5 were examined by Western blot assay and laser scanning confocal microscope, respectively. The results indicated that Hep2 cells turned to spindle-like shapes after exposed to shear stress, and showed the trend of the recovering to original shapes when the shear stress was cancelled. The cell-cell junctions were tight under the shear flow condition, and the permeability was reduced under the condition of 1.4 dyn/cm shear flow. The expressions of tight junction proteins were enhanced with increased duration of shear flow, but reduced after removing shear flow. The result of Claudin-5 expression by immufluorescence assay was consistent with that by Western blot. The Claudin-5 mainly distributed in the cytoplasm under static condition, while it located at the intercellular after shear flow stimulation, and it appeared intercellular and cytoplasm after stopping shear flow stimulation. Therefore, it can be concluded that shear stress changes the morphology of laryngeal squamous carcinoma Hep2 cells, and upregulates the tight junction.
Blotting, Western ; Carcinoma, Squamous Cell ; pathology ; Claudin-5 ; metabolism ; Hep G2 Cells ; Humans ; Laryngeal Neoplasms ; pathology ; Occludin ; metabolism ; Stress, Mechanical ; Tight Junctions ; Zonula Occludens-1 Protein ; metabolism

[ Abstract] Objective To investigate the effect of IL-8 on the viability and migration of HepG2 cells and the potential effect of integrins (αsubunits ) on the migration of HepG2 cells.Methods HepG2 cells were stimulated by IL-8 at different concentrations ranging from 0 to 125 ng/ml in vitro.MTT assay was preformed to detect the viability of HepG2 cells.Scratch wound migration assay was used to explore the effect of IL-8 on the migration of HepG2 cells at the time points of 0, 4, 8, 12 and 24 h,respectively.Transwell assay was conducted to detect the vertical migration of HepG2 cells after stimulation with IL-8 for 24 h.The F-actin of HepG2 cells was observed by immunofluorescence analysis after treatment with IL-8 at different concentrations.The expression of αsubunits of integrins in HepG2 cells treated with IL-8 for 8h was detected using Western boltting assays.Results Compared with the control group, HepG2 cells treated with IL-8 showed improved proliferation activities, but there was no significant difference between the groups of HepG2 cells treated with IL-8 at different concentrations.The cell scratch healing assays and Transwell analysis both indicated that IL-8 promoted the migration of HepG2 cells in a dose-dependent manner.Meanwhile, the cytoskeleton of HepG2 cells was rearranged and the number of filopodium-like protrusions (FLPs) was increased rapidly after treatment with IL-8.Western blotting analysis showed that IL-8 up-regulated the expression of αsubunit of integrins and there was a concentration difference betweenαsubunits.Conclusion IL-8 promotes the migration of HepG2 cells by up-regulating the expression ofαsubunits, and different αsubunits may play different roles.

To study the potential molecular mechanism of tumor angiogenesis in its microenvironment, we investigated the effects of HepG2 conditioned medium on the proliferation of vascular endothelial cell and vascular angiogenesis in our laboratory. Human umbilical vein endothelial EA. hy926 cells were co-cultured with HepG2 conditioned medium in vitro. The proliferation and the tubulogenesis of EA. hy926 cells were detected by teramethylazo salt azole (MTT) and tube formation assay, respectively. The results showed that the survival rate of the EA. hy926 cells was significantly increased under the co-culture condition. HepG2 conditioned medium also enhanced the angiogenesis ability of EA. hy926 cells. In addition, the expressions of intracellular VEGF and extracellular VEGFR (Flk-1) were regulated upward in a time-dependent manner. In conclusion, the proliferation of vascular endothelial cells and Vascula angiogenesis were improved under the condition of indirect co-culture.
Carcinoma, Hepatocellular ; pathology ; Cell Proliferation ; Coculture Techniques ; Culture Media, Conditioned ; Endothelial Cells ; cytology ; Hep G2 Cells ; Human Umbilical Vein Endothelial Cells ; Humans ; Liver Neoplasms ; pathology ; Neovascularization, Pathologic ; Tumor Microenvironment ; Vascular Endothelial Growth Factor A ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism

Low shear stress is a component of the tumor microenvironment in vivo and plays a key role in regulating cancer cell migration and invasion. The integrin, as a mechano-sensors mediating and integrating mechanical and chemical signals, induce the adhesion between cells and extracellular matrix (ECM). The purpose of this study is to investigate the effect of low shear stress (1.4 dyn/cm2)on the migration of HepG2 cells and the expression of integrin. Scratch wound migration assay was performed to examine the effect of low shear stress on the migration of HepG2 cells at 0 h, 1 h, 2 h and 4 h, respectively. F-actin staining was used to detect the expression of F-actin in HepG2 cells treated with low shear stress at 2 h and 4 h. Western blot analysis was carried out to determine the effect of low shear stress on the expression of integrin at different durations. The results showed that the migrated distance of HepG2 cells and the expression of F-actin increased significantly compared with the controls. The integrin alpha subunits showed a different time-dependent expression, suggesting that various subunits of integrin exhibit different effects in low shear stress regulating cancer cells migration.
Actins ; physiology ; Cell Movement ; Extracellular Matrix ; physiology ; Hep G2 Cells ; Humans ; Integrins ; physiology ; Stress, Mechanical