Research progress on m5C methylation and its prospects in tumor immunotherapy / 口腔疾病防治

@#Epigenetic modification plays an important role in the biological regulatory process of eukaryotic cells. Tumor immunotherapy is an important means and clinical strategy for the treatment of some cancers. 5-Methylcytosine (m5C) is an important component of the epigenetic regulatory network discovered after m6A and has become a new topic for life science research in recent years. The m5C methylation of RNA can affect the fate of the modified RNA molecules and play an important role in various biological processes, including RNA stability, protein synthesis and transcriptional regulation. Recent studies have shown that m5C writers, erasers and readers are related to a variety of cellular biological processes and systemic diseases, including the occurrence, metastasis and tumor immune microenvironment. m5C methylation can widely affect gene expression and the biological process of tumorigenesis and development at multiple levels, but its specific mechanism and potential interaction with other epigenetic modifications in tumor immunotherapy are still unclear, and its regulatory mechanism, risk assessment and role in targeted therapy for malignant tumors need to be further studied. This article will review the dynamic regulatory network of m5C, the biological role of m5C modification in solid tumors and potential targets in tumor immunotherapy.

Research progress on pathogenic genes and molecular mechanisms of nonsyndromic tooth agenesis / 口腔疾病防治

@#Tooth agenesis is a common tooth number deficiency that occurs in the tooth-forming process or earlier period of tooth germ development and has a serious impact on the maxillofacial development, aesthetics and masticatory function of patients. According to the presence or absence of systemic symptoms, tooth agenesis can be divided into syndromic tooth agenesis and nonsyndromic tooth agenesis. In recent years, the discovery of new related genes, new mutation sites and related molecular mechanisms has become a major direction of gene research. This article will review the current research progress of the signaling pathways related to nonsyndromic tooth agenesis, such as the WNT/beta-catenin pathway, TGF-β/BMP pathway, PAX9, MSX1, and the EDA/EDAR/NF-κb pathway, and their molecular mechanisms. The interaction between Pax9 activating the Wnt/β-catenin and TGF-β/BMP pathways, MSX1 activating the TGF-β/BMP pathway, and Wnt activating the EDA/EDAR/NF-κb pathway was also found, which provides a new theoretical basis for the prevention and treatment of tooth agenesis. The molecular mechanism of nonsyndromic tooth agenesis is rarely studied; thus, the exploration of its mechanism will become one of the main research directions in the future.

Knockdown of circ_0001273 inhibits the proliferation, migration and invasion of oral squamous cell carcinoma cells / 口腔疾病防治

Objective@#To explore the effect of circ_0001273 on the proliferation, migration and invasion of oral squamous cell carcinoma（OSCC） cells and to provide a relevant research basis for the use of targeted therapy in OSCC. @*Methods@#Data from twelve patients with a clinical diagnosis of OSCC were collected from tumor specimens and adjacent tissues. qRT-PCR was used to detect the expression levels of circ_0001273, circ_0018569, circ_0027152, and circ_0001273 which had the highest difference in expression in cancer and adjacent tissues was selected. siRNA was used for the knockdown of circ_0001273 in two types of OSCC cell lines, UM1 and CAL27, and the effects on the proliferation, migration, and invasion of UM1 and CAL27 cells were measured by MTS and Transwell experiments, respectively. @*Results@#The expression of circ_0001273 was abnormally increased in the 12 OSCC tissues (P < 0.05). After knocking down circ_0001273 in UM1 and CAL27 cells, the proliferation, migration and invasion abilities of UM1 and CAL27 cells were significantly reduced (P < 0.05).@*Conclusion@#The knockdown of circ_0001273 can inhibit the proliferation, migration and invasion of OSCC cells.

Inhibitory effect of reduced graphene oxide-silver nanocomposite on progression of artificial enamel caries

Abstract The use of antimicrobial agents is an efficient method to prevent dental caries. Also, nanometric antibacterial agents with wide antibacterial spectrum and strong antibacterial effects can be applied for prevention of dental caries. Objectives: The aim of this study was to evaluate the inhibitory effect of reduced graphene oxide-silver nanoparticles (rGO/Ag) composite on the progression of artificial enamel caries in a Streptococcus mutans biofilm model. Material and Methods: Enamel specimens from bovine incisors were divided into eight treatment groups (n = 13), as follows: group 1 was inoculated with S. mutans grown in Brain Heart Infusion containing 1% sucrose (1% BHIS), as negative control; groups 2-4 were inoculated with S. mutans grown in the presence of different rGO/Ag concentrations (0.08, 0.12, 0.16 mg/mL) + 1% BHIS; group 5-7 were inoculated with S. mutans grown in the presence of different agents (0.16 mg/mL reduced graphene oxide, 0.16 mg/mL silver nanoparticles, 10 ppm NaF) + 1% BHIS; group 8 was mixed with 1% BHIS, without inoculation. Artificial enamel carious lesions were produced by S. mutans biofilm model for 7 days. Confocal laser scanning microscopy and atomic force microscopy were used to analyze roughness and morphology of the enamel surface. Polarized light microscopy and confocal laser scanning microscopy were employed to measure the lesion depth and the relative optical density (ROD) of the demineralized layer. Results: Compared with the control groups, the rGO/Ag groups showed: (a) reduced enamel surface roughness; (b) much smoother and less eroded surfaces; (c) shallower lesion depth and less mineral loss. Conclusion: As a novel composite material, rGO/Ag can be a promising antibacterial agent for caries prevention.

Expression of miR-21, miR-221, and miR-222 in exosomes of CAL27 tongue squamous cell carcinoma cells / 口腔疾病防治

Objective@# To assess the expression of miR-21, miR-221, and miR-222 in exosomes of CAL27 tongue squamous cell carcinoma cells.@*Methods @# CAL27 tongue squamous cell carcinoma cells and normal human oral keratinocytes (HOKs) were cultured, and then, the cultured supernatant was collected to separate the exosomes. Exosomes were detected by electron microscopy, and the expression levels of miR-21, miR-221, and miR-222 in the exosomes of tongue cancer cells were measured by qRT-PCR. @*Results@#Exosomes existed in the cultured supernatants of CAL27 cells and HOKs. Additionally, the expression levels of miR-21, miR-221, and miR-222 in the exosomes of CAL27 cells were significantly enhanced compared with those in the HOK exosomes (P < 0.05). @*Conclusion @#The expression levels of miR-21, miR-221, and miR-222 were markedly enhanced in the exosomes of CAL27 tongue squamous cell carcinoma cells.

The antimicrobial activity and application of graphene quantum dots in oral medicine / 口腔疾病防治

@#The abuse of antibiotics has been increasing bacterial resistance, which means there is a need to develop methods for the efficient detection and effective treatment of multiresistant bacterial infections. As one of graphene-based materials, graphene quantum dots (GQDs) have distinct mechanical, electrical, and optical properties, including a small size, a large surface area-to-volume ratio, biocompatibility, antimicrobial activity and tunable photoluminescence. Therefore, GQDs are expected to be widely used as antimicrobial materials, drug delivery carriers and photosensitizers in antibacterial applications. In this review, we focus on their synthesis, characteristics and antimicrobial applications in oral medicine.

Research progress of circular RNA and its research prospects in oral diseases / 口腔疾病防治

@#Circular RNAs (circRNAs) are RNAs with a covalently closed loop structure, characterized by its conservation, stability, tissue specific and ubiquity. CircRNAs can serve as miRNA ‘sponges’ to modulate the mRNA targets of miRNAs. CircRNAs can bind with RNA binding proteins and regulate the expression of some genes. The differential expression of circRNAs between pathogenic and normal tissues makes circRNAs possibly promising biomarkers for diagnosis and targets for treatment. In this article, we reviewed the research progress of circRNA and discussed its research prospects in oral diseases.

Research progress of nanomaterials and nanotechnology in cancer radiotherapy sensitization / 口腔疾病防治

@#With the development of nanomaterials and nanotechnology, nanomedicine possesses the vast application prospects in the field of cancer therapy. Although the proportion of radiotherapy in cancer comprehensive therapy is rising, the radiotherapy resistance of cancer cells and the side effects of radiotherapy are the existing problems. Compared with the traditional radiotherapy sensitization, it will present a higher treatment efficiency and lower toxicity to introduce nanomaterials and nanotechnology to cancer radiotherapy. This review elaborates the research of nanomaterials and nanotechnology on cancer radiotherapy sensitization.