Invasion Of KB Cells Research Articles

Erianin inhibits oral cancer cell growth, migration, and invasion via the Nrf2/HO-1/ GPX4 pathway

Objective: To evaluate the effect of erianin on the viability, migration, and invasion of KB cells and elucidate its underlying mechanisms. Methods: Cell Counting Kit-8, colony formation, wound healing, and Transwell assays were used to determine the proliferation, migration, and invasion of oral cancer KB cells. Furthermore, malondialdehyde (MDA) and glutathione (GSH) levels were determined. Fluorescent probes were used to detect changes in intracellular reactive oxygen species and iron ions. Additionally, the expressions of ferroptosis-related proteins, NF-E2-related factor 2 (Nrf2), ferritin heavy chain 1 (FTH1), heme oxygenase 1 (HO-1), and glutathione peroxidase 4 (GPX4) were analyzed by Western blotting assays. Results: Erianin induced ferroptosis and inhibited the proliferation, migration, and invasion of KB cells. Moreover, erianin decreased GSH level, increased MDA level, elevated intracellular ROS and Fe2+ contents, and downregulated the expression of the ferroptosis-related proteins Nrf2, HO-1, GPX4, and FTH1 in KB cells. These effects of erianin were effectively reversed by a ferroptosis inhibitor, ferrostatin-1. Conclusions: Erianin inhibits the proliferation, migration, and invasion of oral cancer cells and induces ferroptosis via the Nrf2/HO-1/GPX4 signaling pathway. Therefore, erianin may be a potential candidate for the treatment of oral cancer.

Exploration of pro-apoptotic effect of Thymoquinone on oral squamous cell carcinoma cells through PI3K/Akt signaling pathway

Oral squamous cell carcinoma (OSCC) is the sixth most prevalent cancer type in the world, with a 5-year survival rate of only 40% to 50%. Finding effective anti-tumor drug candidates is quite necessary for the progression of OSCC therapy. In this study, the role of Thymoquinone (TQ) in OSCC cells was studied. It was confirmed that TQ can inhibit the proliferation, migration and invasion of KB cells, and can also achieve apoptosis by inhibiting the activation of PI3K/Akt pathway. Therefore, TQ is an effective candidate for the treatment of OSCC.

Inhibition of EGF-induced migration and invasion by sulfated polysaccharide of Sepiella maindroni ink via the suppression of EGFR/Akt/p38 MAPK/MMP-2 signaling pathway in KB cells

SIP-SII, the sulfated Sepiella maindroni ink polysaccharide (SIP), has been manifested to possess anti-tumor and anti-metastasis activity in vivo and in vitro. In the present study, we evaluated its inhibitory effect on the epidermal growth factor (EGF)-induced migration and invasion of human epidermoid carcinoma cell (KB cell line) as well as the related signaling pathways. The results of MTT assay indicated that SIP-SII inhibited the proliferation of KB cells in a concentration and time dependent manner. Notably, the attenuation of cell growth by SIP-SII was enlarged in the presence of EGF. The wound healing assay and transwell invasion assay were used to evaluate the effect of SIP-SII on the EGF-induced migration and invasion of KB cells and the results showed that SIP-SII markedly attenuated the EGF-induced migration and invasion. Besides, the EGF-induced matrix metalloproteinase-2 (MMP-2) expression was also suppressed by SIP-SII. However, SIP-SII showed no significant inhibition of the EGF-induced matrix metalloproteinase-9 (MMP-9) expression. Further research revealed that SIP-SII decreased the EGF-induced phosphorylation of epidermal growth factor receptor (EGFR), Akt and p38, but no significant suppression on EGF-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (Erk1/2) and c-Jun N-terminal kinases (JNK) by SIP-SII treatment was observed. The involvement of EGFR/Akt/p38 pathway was confirmed by evidence that SIP-SII would enlarge the inhibitory effect of the specific signal pathway inhibitors. These results indicate that SIP-SII has the potential to be used as the inhibitor of tumor metastasis especially for cancers characterized by over-activation of EGF/EGFR signaling.

Synthesis of Glycosides of Resveratrol, Pterostilbene, and Piceatannol by Glucosyltransferase from Phytolacca americana Expressed in Bacillus subtilis and their Chemopreventive Activity Against Cancer, Allergic, and Alzheimer’s Diseases

Resveratrol was glucosylated to its 3- and 4'-β-glucosides by the glucosyltransferase PaGT3 from Phytolacca americana expressed in Bacillus subtilis. PaGT3 glucosylated pterostilbene to its 4'-β-glucoside. Piceatannol was converted into its 4'-β-glucoside by PaGT3. Resveratrol 3-β-glucoside showed the inhibitory action of adhesion, migration, and invasion of KB cells. The resveratrol 3-β-glucoside would act as a chemopreventive agent against KB cells. Piceatannol 4'-β-glucoside showed the strongest inhibitory activity among the glycosides toward histamine release from rat peritoneal mast cells. The 4'-β-glucoside of piceatannol would be a potential therapeutic agent for allergic disease. Pterostilbene 4'-β-glucoside showed high phosphodiesterase (PDE) inhibitory activity. The 4'-β-glucoside of pterostilbene could be a potential chemopreventive agent for Alzheimer’s disease.

Effect of secretory leukocyte protease inhibitor on migration and invasion of human KB oral carcinoma cells

Secretory leukocyte protease inhibitor (SLPI) plays an important role in promoting the invasion and metastasis of a range of cancer cells. However, there are no reports of the expression and function of SLPI in oral carcinoma cells. In this study, the oral carcinoma cell line KB was used to determine whether SLPI affects the proliferation, migration and invasion of oral carcinoma cells. RT-PCR and Western blotting revealed high levels of endogenous SLPI expression in KB cells as well as a strong increase in SLPI secretion after wounding compared to immortalized normal oral keratinocytes (INOK). The wound healing assay revealed more migration of KB cells than INOK cells, and the SLPI treatment increased the migration of KB cells. KB cell proliferation was increased significantly by the SLPI protein but decreased by SLPI-siRNA. SLPI strongly increased the migration and invasion of KB cells. On the other hand, SLPI-siRNA decreased the migration and invasion of KB cells. This suggests that SLPI plays an important role in the metastasis of oral carcinoma cells.

Effect ofWeissella cibariaonFusobacterium nucleatum-induced Interleukin-6 and Interleukin-8 Production in KB Cells

Oral microorganisms, including pathogens together with commensals, interact with oral epithelial cells, which can lead to the activation and expression of a variety of inflammatory mediators in epithelial cells. Fusobacterium nucleatum is a filamentous human pathogen that is strongly associated with periodontal diseases. Our previous data suggest that Weissella cibaria, an oral commensal, inhibits the proliferation of periodontopathic bacteria including F. nucleatum. The aim of this study was to examine the effects of W. cibaria on the inflammatory mediators, interleukin (IL)-6 and IL-8, in KB cells stimulated by F. nucleatum. In a reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay, live F. nucleatum alone induced high levels of gene expression and protein release of IL-6 and IL-8, whereas W. cibaria alone did not induce IL-6 and IL-8 responses in KB cells. W. cibaria dose-dependently inhibited the increases of the IL-6 and IL-8 gene expression as well as IL-6 protein level in KB cells which was induced by F. nucleatum. Bacterial viability and its coaggregation with F. nucleatum are not essential in the inhibitory effect of W. cibaria. Visible effects of W. cibaria on the attachment and invasion of KB cells by F. nucleatum were observed. In conclusion, W. cibaria may exert immunomodulatory effects on the IL-6 and IL-8 responses to F. nucleatum-activated KB cells.

Effects of methyl gallate and gallic acid on the production of inflammatory mediators interleukin-6 and interleukin-8 by oral epithelial cells stimulated with Fusobacterium nucleatum

Interactions between periodontal bacteria and human oral epithelial cells can lead to the activation and expression of a variety of inflammatory mediators in epithelial cells. Fusobacterium nucleatum is a filamentous human pathogen that is strongly associated with periodontal diseases. This study examined the effects of methyl gallate (MG) and gallic acid (GA) on the production of inflammatory mediators, interleukin (IL)-6 and IL-8, by oral epithelial cells stimulated by F. nucleatum. In a real-time reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay, live F. nucleatum induced high levels of gene expression and protein release of IL-6 and IL-8. The effects of MG and GA were examined by treating KB oral epithelial cells with MG and GA and stimulating them with F. nucleatum. MG and GA inhibited significantly the increases in the IL-6 and IL-8 gene and protein levels in a dose-dependent manner. These Compounds also inhibited the growth of F. nucleatum. No visible effects of MG and GA on the adhesion and invasion of KB cells by F. nucleatum were observed. In conclusion, both MG and GA inhibit IL-6 and IL-8 production from F. nucleatum-activated KB cells.

Fusobacterium nucleatum transports noninvasive Streptococcus cristatus into human epithelial cells.

Analysis of human buccal epithelial cells frequently reveals an intracellular polymicrobial consortium of bacteria. Although several oral bacteria have been demonstrated to invade cultured epithelial cells, several others appear unable to internalize. We hypothesized that normally noninvasive bacteria may gain entry into epithelial cells via adhesion to invasive bacteria. Fusobacterium nucleatum is capable of binding to and invading oral epithelial cells. By contrast, Streptococcus cristatus binds weakly to host cells and is not internalized. F. nucleatum and S. cristatus coaggregate strongly via an arginine-sensitive interaction. Coincubation of KB or TERT-2 epithelial cells with equal numbers of F. nucleatum and S. cristatus bacteria led to significantly increased numbers of adherent and internalized streptococci. F. nucleatum also promoted invasion of KB cells by other oral streptococci and Actinomyces naeslundii. Dissection of fusobacterial or streptococcal adhesive interactions by using sugars, amino acids, or antibodies demonstrated that this phenomenon is due to direct attachment of S. cristatus to adherent and invading F. nucleatum. Inhibition of F. nucleatum host cell attachment and invasion with galactose, or fusobacterial-streptococcal coaggregation by the arginine homologue l-canavanine, abrogated the increased S. cristatus adhesion to, and invasion of, host cells. In addition, polyclonal antibodies to F. nucleatum, which inhibited fusobacterial attachment to both KB cells and S. cristatus, significantly decreased invasion by both species. Similar decreases were obtained when epithelial cells were pretreated with cytochalasin D, staurosporine, or cycloheximide. These studies indicate that F. nucleatum may facilitate the colonization of epithelial cells by bacteria unable to adhere or invade directly.

Two epithelial cell invasion-related loci of the oral pathogen Actinobacillus actinomycetemcomitans.

Two invasion-related loci, apiA and the two-gene operon apiBC, were isolated from the oral pathogen Actinobacillus actinomycetemcomitans UT32. apiA encodes a 32.5 kDa protein that migrates on SDS-PAGE as a 101 kDa protein as detected by Western blot analysis or silver staining of an outer membrane-enriched fraction of Escherichia coli transformants. E. coli expressing ApiA have a different phenotype than the host vector, in broth and on solid media, and a colony morphology that resembles that of fresh A. actinomycetemcomitans isolates. These E. coli transformants bound to chicken collagen type II, human collagen type II, III, V and fibronectin. apiB and apiC encode proteins of 130.1 and 70.6 kDa, respectively. ApiBC conferred on E. coli a slightly enhanced ability to bind to collagen type III. ApiA- and ApiB-deficient mutants were constructed in A. actinomycetemcomitans. The ApiB-mutant had 4-fold diminished invasion of KB cells; the ApiA-mutant had increased invasion. Both loci were found in all A. actinomycetemcomitans strains, although polymorphism was detected only for apiBC. The deduced sequences of these invasion-related proteins are homologous to members of the YadA adhesin/invasin family.

A role for fimbriae in Porphyromonas gingivalis invasion of oral epithelial cells.

Isogenic mutants of Porphyromonas gingivalis which differ in the expression of fimbriae were used to examine the contribution of fimbriae in invasion of a human oral epithelial cell line (KB). At a multiplicity of infection of 100, the wild-type P. gingivalis strains 33277, 381, and A7436 exhibited adherence efficiencies of 5.5, 0.11, and 5.0%, respectively, and invasion efficiencies of 0.15, 0.03, and 0.10%, respectively. However, adherence to and invasion of KB cells was not detected with the P. gingivalis fimA mutants, DPG3 and MPG1. Adherence of P. gingivalis wild-type strains to KB cells was completely inhibited by the addition of hyperimmune sera raised to the major fimbriae. Examination by electron microscopy of invasion of epithelial cells by the P. gingivalis wild-type strain 381 revealed microvillus-like extensions around adherent bacteria; this was not observed with P. gingivalis fim mutants. Taken together, these results indicate that the P. gingivalis major fimbriae are required for adherence to and invasion of oral epithelial cells.

Requirements for invasion of epithelial cells by Actinobacillus actinomycetemcomitans.

Actinobacillus actinomycetemcomitans, an oral bacterium implicated in human periodontal disease, was recently demonstrated to invade cultured epithelial cells (D. H. Meyer, P. K. Sreenivasan, and P. M. Fives-Taylor, Infect. Immun. 59:2719-2726, 1991). This report characterizes the requirements for invasion of KB cells by A. actinomycetemcomitans. The roles of bacterial and host factors were investigated by using selective agents that influence specific bacterial or host cell functions. Inhibition of bacterial protein synthesis decreased invasion, suggesting the absence of a preformed pool of proteins involved in A. actinomycetemcomitans invasion. Inhibition of bacterial and eukaryotic energy synthesis also decreased invasion, confirming that A. actinomycetemcomitans invasion is an active process. Bacterial adherence to KB cells was indicated by scanning electron microscopy of infected KB cells. Further, the addition of A. actinomycetemcomitans-specific serum to the bacterial inoculum reduced invasion substantially, suggesting a role for bacterial attachment in invasion. Many of the adherent bacteria invaded the epithelial cells under optimal conditions. Inhibitors of receptor-mediated endocytosis inhibited invasion by A. actinomycetemcomitans. Like that of many facultatively intracellular bacteria, A. actinomycetemcomitans invasion was not affected by eukaryotic endosomal acidification. These are the first published observations describing the requirements for epithelial cell invasion by a periodontopathogen. They demonstrate that A. actinomycetemcomitans utilizes a mechanism similar to those used by many but not all invasive bacteria to gain entry into eukaryotic cells.