Oral Microflora in the Background of Oral Cancer: A Review

Bioactive plant waste components targeting oral bacterial pathogens as a promising strategy for biofilm eradication

The significance of this study lies in its exploration of bioactive plant extracts as a promising avenue for combating oral bacterial pathogens, offering a novel strategy for biofilm eradication that could potentially revolutionize oral health treatments. Oral bacterial infections are common in diabetic patients; however, due to the development of resistance, treatment options are limited. Considering the excellent antimicrobial properties of phenolic compounds, we investigated them against isolated oral pathogens using in silico and in vitro models. We performed antibiogram studies and minimum inhibitory concentration (MIC), antibiofilm, and antiquorum sensing activities covering phenolic compounds. Bacterial strains were isolated from female diabetic patients and identified by using 16S rRNA sequencing as Pseudomonas aeruginosa, Bacillus chungangensis, Bacillus paramycoides, and Paenibacillus dendritiformis. Antibiogram studies confirmed that all strains were resistant to most tested antibiotics except imipenem and ciprofloxacin. Molecular docking analysis revealed the significant interaction of rutin, quercetin, gallic acid, and catechin with transcription regulator genes 1RO5, 4B2O, and 5OE3. All tested molecules followed drug-likeness rules except rutin. The MIC values of the tested compounds varied from 0.0625 to 0.5 mg/mL against clinical isolates. Significant antibiofilm activity was recorded in the case of catechin (73.5% ± 1.6% inhibition against B. paramycoides), cinnamic acid (80.9% ± 1.1% inhibition against P. aeruginosa), and vanillic acid and quercetin (65.5% ± 1.7% and 87.4% ± 1.4% inhibition, respectively, against B. chungangensis) at 0.25-0.125 mg/mL. None of the phenolic compounds presented antiquorum sensing activity. It was, therefore, concluded that polyphenolic compounds may have the potential to be used against oral bacterial biofilms, and further detailed mechanistic investigations should be performed.

Association of DOK3 and infiltrated tumor-associated macrophages with risk for the prognosis of Porphyromonas gingivalis-infected oral cancer: a 12-year data analysis of 200 patients from a tertiary teaching hospital, Urumqi, China

BACKGROUND

While there is an understanding of the association between the expression of Porphyromonas gingivalis (P. gingivalis) and prognosis of oral squamous cell carcinoma (OSCC), significance specially to address the relevance between different immunohistochemical intensities of P. gingivalis and tumor-associated macrophages (TAMs) in OSCC tissue and related clinicopathologic characteristics has not been well investigated. The present study aimed to investigate the pathological features related to M2-TAM in P. gingivalis-infected OSCC and ascertain its clinical relevance with patients' prognosis.

METHODS

A prospective cohort study was designed to comparatively analyze 200 patients from June 2008 to June 2020. Bioinformatics analyses were implemented to identify DOK3 as a key molecule and to appraise immunocyte infiltration using Gene Expression Omnibus and The Cancer Genome Atlas databases. Immunohistochemical evaluation was performed to analyze the association between the expression levels of P. gingivalis, DOK3, and M2-TAM and clinicopathological variables using Fisher's exact test or Pearson's chi-square test. Cox analysis was used to calculate hazard ratios (HR) with corresponding 95% confidence interval (CI) for various clinicopathological features. The Kaplan-Meier approach and log-rank test were used to plot the survival curves.

RESULTS

The expression level of P. gingivalis was positively associated with DOK3 and M2-TAMs expression level (P < 0.001). Parameters, including body mass index, clinical stage, recurrence, tumor differentiation, and P. gingivalis, DOK3, and M2-TAM immunoexpression levels, affected the prognosis of patients with OSCC (all P < 0.05). In addition, P. gingivalis (HR = 1.674, 95%CI 1.216-4.142, P = 0.012), DOK3 (HR = 1.881, 95%CI 1.433-3.457, P = 0.042), and M2-TAM (HR = 1.649, 95%CI 0.824-3.082, P = 0.034) were significantly associated with the 10-year cumulative survival rate.

CONCLUSIONS

Elevated expression of P. gingivalis and DOK3 indicates M2-TAM infiltration and unfavorable prognosis of OSCC, and could be considered as three novel independent risk factors for predicting the prognosis of OSCC.

A bibliometric and visualized in oral microbiota and cancer research from 2013 to 2022

Numerous studies have highlighted the implication of oral microbiota in various cancers. However, no bibliometric analysis has been conducted on the relationship between oral microbiota and cancer. This bibliometric analysis aimed to identify the research hotspots in oral microbiota and cancer research, as well as predict future research trends. The literature published relating to oral microbiota and cancer was searched from the Web of Science Core Collection database (WoSCC) from 2013 to 2022. VOSviewer or Citespace software was used to perform the bibliometric analysis, focusing on countries, institutions, authors, journals, keywords and references. A total of 1516 publications were included in the analysis. The number of publications related oral microbiota and cancer increased annually, reaching its peak in 2022 with 287 papers. The United States (456) and China (370) were the countries with the most publications and made significant contributions to the field. Sears CL and Zhou XD were the most productive authors. The high frequency of keywords revealed key topics, including cancer (colorectal cancer, oral cancer), oral microbiota (Fusobacterium nucleatum, Porphyromonas gingivalis), and inflammation (periodontal disease). The latest trend keywords were F. nucleatum, dysbiosis, prognosis, tumor microenvironment, gastric microbiota, complications and survival, suggesting a new hotspot in the field of oral microbiota and cancer. Our study provides a comprehensive analysis of oral microbiota and cancer research, revealing an increase in publications in recent years. Future research directions will continue to focus on the diversity of oral microbiota impacted by cancers and the underlying mechanism connecting them, providing new ideas for targeted therapy of tumorigenesis.