Oral bacterial infections substantially affect the development of various periodontal diseases and oral cancers. However, the molecular mechanisms underlying the association between Fusobacterium nucleatum (F. nucleatum ), a major periodontitis (PT)-associated pathogen, and these diseases require extensive research. Previously, our RNAsequencing analysis identified a few hundred differentially expressed genes in patients with PT and peri-implantitis (PI) than in healthy controls. Thus, in the present study using oral squamous cell carcinoma (OSCC) cells, we aimed to evaluate the effect of F. nucleatum infection on genes that are differentially regulated in patients with PT and PI. Human oral squamous cell carcinoma cell lines OSC-2O, HSC-4, and HN22 were used. These cells were infected with F. nucleatum at a multiplicity of infection of 100 for 3 hours at 37℃ in 5% CO2. Gene expression was then measured using reverse-transcription polymerase chain reaction. Among 18 genes tested, the expression of CSF3, an inflammation-related cytokine, was increased by F. nucleatum infection. Additionally, F. nucleatum infection increased the phosphorylation of AKT, p38 MAPK, and JNK in OSC-20 cells. Treatment with p38 MAPK (SB202190) and JNK (SP600125) inhibitors reduced the enhanced CSF3 expression induced by F. nucleatum infection. Overall, this study demonstrated that F. nucleatum promotes CSF3 expression in OSCC cells through p38 MAPK and JNK signaling pathways, suggesting that p38 MAPK and JNK inhibitors may help treat F. nucleatum-related periodontal diseases by suppressing CSF3 expression.
Glutamate-mediated oxidative stress causes neuronal cell death by increasing intracellular Ca2+ uptake, reactive oxidative species (ROS) generation, mitogen-activated protein kinase (MAPK) activation, and translocation of apoptosis-inducing factor (AIF) to the nucleus. In the current study, we demonstrated that corydaline exerts potent neuroprotective effects against glutamate-induced neurotoxicity. Treatment with 5 mmol/L glutamate increased cellular Ca2+ influx, ROS generation, MAPK activation, and AIF translocation. In contrast, corydaline treatment decreased cellular Ca2+ influx and ROS generation. Western blot analysis revealed that glutamate-mediated MAPK activation was attenuated by corydaline treatment. We further demonstrated that corydaline treatment inhibited the glutamate-mediated translocation of AIF to the nucleus. We propose that corydaline is a promising lead structure for the development of safe and effective neuroprotectants.
Despite advancements in therapeutic approaches, radiotherapy and cisplatin-based chemotherapy remain primary noninvasive treatments for patients with oral squamous cell carcinoma (OSCC). Moreover, the 5-year survival rate for patients with OSCC has remained almost unchanged for several decades, and many side effects of chemotherapy still exist. In this study, three-dimensional (3D) models of OSCC were established using fibroblasts, and the efficacy of various biological inhibitors was evaluated. A culture of epithelial cells with two types of fibroblasts (hTERT-hNOFs and cancer-associated fibroblasts) within a type I collagen matrix resulted in the formation of a continuous layer of tightly packed cells compared to models without fibroblasts. Furthermore, the effects of biological chemicals, including Y27632, latrunculin A, and verteporfin, on these models were investigated. The stratified formation of the epithelial layer and invasion in OSCC 3D-culture models were effectively inhibited by verteporfin, whereas invasion was weakly inhibited by Y27632 and latrunculin. Collectively, the developed OSCC 3D-culture models established with fibroblasts demonstrated the potential for drug screening, with verteporfin showing promising efficacy.