Background: Non-coding RNA molecules, such as microRNAs, may play an important role in carcinogenesis. Recent studies have indicated that microRNAs are involved in initiation and progression of various malignancies. However, little work has been done to compare the microRNA expression patterns in oral cancer. In this study, we constructed an animal model of oral squamous cell carcinoma to investigate expression profiles of microRNAs in oral carcinogenesis.

Aim To explore the function and mechanisms of NLRP6 (NOD‐, LRR‐ and pyrin domain‐containing 6) in the inflammatory response of human periodontal ligament cells (HPDLCs). Methodology Tissues associated with apical periodontitis were obtained from three patients who underwent endodontic microsurgery. The expression of NLRP6 in 3 human apical periodontitis tissues and HPDLCs was examined by immunohistochemistry and immunofluorescence, respectively. The expressions of NLRP6, Phospho(p)‐ p65, p65, IκB‐α, p‐ IκB‐α, ERK, p‐ ERK, NLRP3, Pro interleukin (IL)‐1β, Pro caspase‐1 and apoptosis‐associated speck‐like protein containing a CARD (ASC) were examined by western blot. The gene expression and secretion of proinflammatory cytokines were detected using quantitative real‐time polymerase chain reaction and enzyme‐linked immunosorbent assay. Data were analysed statistically with independent sample t‐tests. Results NLRP6 was expressed in inflammatory periapical tissues and HPDLCs. Lipopolysaccharide (LPS) from Escherichia coli induced NLRP6 in HPDLCs (P < 0.05). After silencing NLRP6, E. coli LPS‐induced activation of NF‐κB and ERK signalling was enhanced, which was also accompanied by elevated levels of IL‐6 and tumour necrosis factor‐α (TNF‐α) (P < 0.05). Moreover, knockdown of NLRP6 led to up‐regulation of NLRP3, Pro IL‐1β and Pro caspase‐1 (P < 0.05), whereas down‐regulation of ASC (P < 0.05), which may contribute to unchanged levels of IL‐1β in HPDLCs inflammation. Conclusion NLRP6 was functionally expressed in inflamed periapical tissues and HPDLCs. NLRP6 negatively regulated the production of IL‐6 and TNF‐α in HPDLCs inflammation by inhibiting NF‐κB and ERK signal pathways.

Background and Objective Diabetes influences the frequency and development of periodontitis. Inflammation of human periodontal ligament cells (HPDLCs) participates in this pathologic process. Hence, this study aims to explore whether advanced glycation end products (AGEs), by‐products of diabetes, could exaggerate inflammation induced by muramyl dipeptide (MDP) in HPDLCs, and whether nucleotide‐binding oligomerization domain‐like receptors (NLRs) signaling pathway was involved. Material and Methods Human periodontal ligament cells were pre‐treated with 100 μg/mL AGEs for 24 hours and stimulated with 10 μg/mL MDP for 24 hours. IL‐6, IL‐1β, and RAGE were detected, and the activation of NF‐κB signaling pathway was observed. The expression of NLRs was evaluated with or without silencing RAGE or blocking NF‐κB pathway under AGEs stimulation. Statistical analyses were performed by using independent sample t test. Results Advanced glycation end products induced significant increase of inflammatory cytokines in HPDLCs (P < 0.05). Results of western blot (WB) showed that after 45 minutes stimulation of AGEs, p‐p65/p65 ratio peaked; AGEs promoted the expression of NLRP1, NLRP3, and apoptosis‐associated speck‐like protein containing a CARD (ASC). After silencing RAGE or blocking NF‐κB pathway, the up‐regulation of NLRs protein caused by AGEs was attenuated. Additionally, AGEs pre‐treatment could enhance the inflammatory response of MDP and the expression of NLRs, which were demonstrated by more expression of IL‐6, IL‐1β, NOD2, NLRP1, NLRP3, and ASC. Conclusion Advanced glycation end products induced inflammatory response in HPDLCs via NLRP1‐inflammasome and NLRP3‐inflammasome activation in which NF‐κB signal pathway was involved. Besides, AGEs promoted the inflammatory response of MDP via NOD2, NLRP1‐inflammasome, and NLRP3‐inflammasome.

The survival prognosis of human papillomavirus (HPV)-positive and HPV-negative head and neck squamous cell carcinoma (HNSCC) is largely different, and little is known about the anti-tumor mechanism of tumor-infiltrated exhausted CD8+ T cells (Tex) in HNSCC. We performed cell-level multi-omics sequencing on human HNSCC samples to decipher the multi-dimensional characteristics of Tex cells. A proliferative exhausted CD8+ T cell cluster (P-Tex) which was beneficial to survival outcomes of patients with HPV-positive HNSCC was identified. Interestingly, P-Tex cells expressed CDK4 genes as high as cancer cells, which could be simultaneously inhibited by CDK4 inhibitors and might be a potential reason for the ineffectiveness of CDK4 inhibitors in treating HPV-positive HNSCC. P-Tex cells could aggregate in the antigen-presenting cell niches and activate certain signaling pathways. Together, our findings suggest a promising role for P-Tex cells in the prognosis of patients with HPV-positive HNSCC by providing modest but persistent anti-tumor effects.

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