The Oral Microbiome and Cancer

Altered Bacteria Abundance Is Associated With Outcomes in Head and Neck Squamous Cell Carcinoma

OBJECTIVE

To determine if microbiome differences exist in head and neck squamous cell carcinoma (HNSCC) based on high-risk pathologic features, smoking, and outcomes using The Cancer Microbiome Atlas (TCMA).

STUDY DESIGN

Database study.

SETTING

Database review.

METHODS

TCMA is a publicly available database containing curated, decontaminated microbial profiles for tumors from 1772 patients. The data were limited to microbiome profiles, survival, and clinicopathologic features for HNSCC patients. Phyloseq objects were created, low-read samples were removed, and differential abundance analysis (DAA) using Analysis of Compositions of Microbiomes with Bias Correction 2 (ANCOM-BC2) was performed. Statistical analysis was done in R (v4.3.1).

RESULTS

One hundred fifty-six patients with HNSCC were included from TCMA with a mean age of 59 (std 13, min 19, and max 90), 72% male (n = 113), and 91% white (n = 140). Primary sites encompassed oral cavity (n = 106, 68%), oropharynx (n = 26, 17%), and larynx/hypopharynx (n = 24, 15%). For all HNSCC in TCMA, rates of lymphovascular invasion were 17% (n = 26), perineural invasion, 34% (n = 53), and microscopic or gross extranodal extension (ENE), 19% (n = 30). DAA revealed significant changes in bacterial genera based on high-risk pathologic features, smoking status, vital status, and disease-specific survival (DSS). Genera observed with ANCOM-BC2 include Scardovia, Alloscardovia, Lactobacillus, and Corynebacterium genera for vital status and DSS.

CONCLUSION

Changes in the relative abundance of select intratumoral bacterial genera are associated with adverse pathologic features, DSS, and vital status in HNSCC. Shifts in the microbiome need further investigation to determine if they can provide any mechanistic insight or predictive role.

Association between decreased p53 expression, elevated serum CagA levels, and oral squamous cell carcinoma

OBJECTIVE

p53 is a key tumor suppressor, aCnd loss of p53 function promotes the progression of many cancers. Helicobacter Pylori (HP) is mainly involved in the progression of gastric carcinoma, but its role in Oral Squamous Cell Carcinoma (OSCC) is controversial. The primary objectives of this study were to investigate the expression levels of p53 in OSCC tissues and to examine the serum levels of CagA in OSCC patients. Additionally, the authors aimed to explore the potential association between p53 expression and CagA levels in OSCC.

METHOD

A total of 65 patients diagnosed with OSCC and 42 healthy volunteers were recruited in this study. The clinical pathological parameters of all patients were collected. Reverse transcription-quantitative polymerase chain reaction was performed to detect the expression of p53 in tissues. Receiver Operating Characteristics Curve (ROC) analysis was used to assess the sensitivity of p53 for the diagnosis of OSCC. The concentration of Cytotoxin-Associated gene A (CagA) in serum was assessed by enzyme-linked immuno sorbent assay.

RESULTS

The results indicated that the p53 expression in oral mucosal tissues was downregulated while the concentration of CagA in serum was increased in OSCC patients. Besides, p53 expression was correlated with tumor stage. OSCC patients showed a higher HP positive rate than in healthy people.

CONCLUSIONS

In conclusion, this study demonstrated that decreased p53 expression and elevated serum CagA levels might be correlated with OSCC progression and diagnosis.

Decoding Salivary ncRNAomes as Novel Biomarkers for Oral Cancer Detection and Prognosis

Oral cancer (OC) ranks among the most prevalent head and neck cancers, becoming the eleventh most common cancer worldwide with ~350,000 new cases and 177,000 fatalities annually. The rising trend in the occurrence of OC among young individuals and women who do not have tobacco habits is escalating rapidly. Surgical procedures, radiation therapy, and chemotherapy are among the most prevalent treatment options for oral cancer. To achieve better therapy and an early detection of the cancer, it is essential to understand the disease's etiology at the molecular level. Saliva, the most prevalent body fluid obtained non-invasively, holds a collection of distinct non-coding RNA pools (ncRNAomes) that can be assessed as biomarkers for identifying oral cancer. Non-coding signatures, which are transcripts lacking a protein-coding function, have been identified as significant in the progression of various cancers, including oral cancer. This review aims to examine the role of various salivary ncRNAs (microRNA, circular RNA, and lncRNA) associated with disease progression and to explore their functions as potential biomarkers for early disease identification to ensure better survival outcomes for oral cancer patients.

Complex of intratumoral mycobiome and bacteriome predicts the recurrence of laryngeal squamous cell carcinoma

Dysbiosis of intratumoral fungal and bacterial communities is associated with poor prognosis in various cancers. However, the mycobiome characteristics in laryngeal squamous cell carcinoma (LSCC) and its correlation with recurrence have not yet been investigated. The mycobiome in 80 LSCC samples was characterized using internal transcribed spacer sequencing, encompassing both tumor tissues and their matched para-cancerous tissues. The intratumoral bacteriome was further identified using 16S rRNA sequencing. These two microbial communities were analyzed using bioinformatics and statistical methods to determine its potential correlation with LSCC recurrence. The fungal alpha diversity in tumors was higher compared with that in para-cancerous tissues (P < 0.001). A significant difference in the overall fungal community patterns between tumor tissues and para-cancerous tissues was observed based on Bray-Curtis dissimilarity (P < 0.001). The presence of Alloprevotella, Porphyromonas, Candida, and Fusarium in tumors exhibited a correlation with alcohol consumption. The relative abundance of Penicillium, Exophiala, and Aspergillus in the mycobiome, as well as that of Alloprevotella, Porphyromonas, and Peptostreptococcus in the bacteriome significantly increased the risk of LSCC recurrence (P < 0.05). These six microorganisms can combine to form a microbial complex, which may independently contribute to recurrence risk in patients with LSCC when enriched within the tumor (hazard ratio = 6.844, P < 0.01). Intratumoral fungi and bacteria can be valuable indicators for assessing recurrence in patients with LSCC, indicating their potential as valuable targets for therapeutic intervention.

IMPORTANCE

Our results revealed that dysbiosis of intratumoral microbiota, including increased fungal community diversity and overgrowth of several fungal or bacterial organisms, is substantially linked to the recurrence of LSCC. Drinking habits might alter the laryngeal microbiota to influence the recurrence of LSCC. We also explored a method to potentially predict the recurrence of LSCC from a novel perspective. These findings could offer insights into the etiology of LSCC and pave way to prevent and treat LSCC.

Unveiling familial aggregation of nasopharyngeal carcinoma: Insights from oral microbiome dysbiosis

Familial aggregation is common in nasopharyngeal carcinoma (NPC), yet the impact of oral microbiome dysbiosis on this occurrence remains largely unexplored. We recruit 127 families (649 members, 1-5 patients each) and a case-control cohort of 337 individuals, validating findings in an additional cohort of 995 individuals. Significant microbial similarity is observed among family members, with family factors contributing most to microbiome variation, followed by cigarette smoking, age, and gender. Among multi-NPC families, especially those with three or more patients, we identify three NPC-enriched taxa with notable heritability, including Gemella sp. (heritability, h2 = 53.1%), Lautropia mirabilis (h2 = 38.8%), and Streptococcus sp. (h2 = 38.0%). Heritable bacteria present a markedly higher heritability in families with increased clustering of NPC and form closely interacting networks, suggesting their role in NPC familial aggregation. These findings open up possibilities for identifying high-risk individuals, enhancing clinical surveillance, and developing personalized prevention and treatment approaches of NPC through microbiome-based strategies.

Exploring the role of oral bacteria in oral cancer: a narrative review

A growing body of research indicates that a wide range of cancer types may correlate with human microbiome components. On the other hand, little is known about the potential contribution of the oral microbiota to oral cancer. However, some oral microbiome components can stimulate different tumorigenic processes associated with the development of cancer. In this line, two prevalent oral infections, Porphyromonas gingivalis, and Fusobacterium nucleatum can increase tumor growth. The microbiome can impact the course of the illness through direct interactions with the human body and major modifications to the toxicity and responsiveness to different kinds of cancer therapy. Recent research has demonstrated a relationship between specific phylogenetic groupings and the results of immunotherapy treatment for particular tumor types. Conversely, there has been a recent upsurge in interest in the possibility of using microbes to treat cancer. At the moment, some species, such as Salmonella typhimurium and Clostridium spp., are being explored as possible cancer treatment vectors. Thus, understanding these microbial interactions highlights the importance of maintaining a healthy oral microbiome in preventing oral cancers. From this perspective, this review will discuss the role of the microbiome on oral cancers and their possible application in oral cancer treatment/improvement.

Causal Association Between Microbiome and Oral-Oropharyngeal Cancer: A Mendelian Randomization Study

INTRODUCTION AND AIMS

This study aimed to examine the causal link between oral microbiome and the risk of oral and oropharyngeal squamous cell carcinoma (OOPSCC) using Mendelian randomization (MR).

METHODS

Utilizing single nucleotide polymorphisms as instrumental variables, we applied the MR inverse-variance weighted approach to assess the impact of salivary and tongue microbiome on OOPSCC. The data were obtained from the CNGBdb database and the UK Biobank, and analytical procedures were performed using the R package 'TwoSampleMR'. To ensure the robustness of our findings, we conducted sensitivity studies, which included the MR-Egger intercept test, to establish strong correlations and eliminate the phenomenon of horizontal pleiotropy.

RESULT

Our large-scale MR study revealed a genetically predisposed causal relationship between 13 microbial taxa, each from saliva and tongue, with OOPSCC. Notably, microbial taxa from six genera, including Prevotella, Neisseria, Veillonella, Granulicatella, Treponema, and Streptococcus, in both salivary and tongue microbiomes, showed this relationship. Conversely, several taxa, including Hemophilus, Solobacterium, Campylobacter, and Porphyromonas, predominantly demonstrated an inverse relationship, suggesting a protective effect. The robustness of our findings was further confirmed through sensitivity analyses, providing additional confidence in our results.

CONCLUSION

Our MR study indicates that the oral microbiota has a significant causal impact on the risk of oral and oropharyngeal cancers. The microbial biomarkers we identified, which are linked to OOPSCC, have the potential to uncover the underlying mechanisms and pave the way for new therapeutic approaches for targeted treatment of these malignancies.

Comparative analysis of the human microbiome from four different regions of China and machine learning-based geographical inference

The human microbiome, the community of microorganisms that reside on and inside the human body, is critically important for health and disease. However, it is influenced by various factors and may vary among individuals residing in distinct geographic regions. In this study, 220 samples, consisting of sterile swabs from palmar skin and oral and nasal cavities were collected from Chinese Han individuals living in Shanghai, Chifeng, Kunming, and Urumqi, representing the geographic regions of east, northeast, southwest, and northwest China. The full-length 16S rRNA gene of the microbiota in each sample was sequenced using the PacBio single-molecule real-time sequencing platform, followed by clustering the sequences into operational taxonomic units (OTUs). The analysis revealed significant differences in microbial communities among the four regions. Cutibacterium was the most abundant bacterium in palmar samples from Shanghai and Kunming, Psychrobacter in Chifeng samples, and Psychrobacillus in Urumqi samples. Additionally, Streptococcus and Staphylococcus were the dominant bacteria in the oral and nasal cavities. Individuals from the four regions could be distinguished and predicted based on a model constructed using the random forest algorithm, with the predictive effect of palmar microbiota being better than that of oral and nasal cavities. The prediction accuracy using hypervariable regions (V3-V4 and V4-V5) was comparable with that of using the entire 16S rRNA. Overall, our study highlights the distinctiveness of the human microbiome in individuals living in these four regions. Furthermore, the microbiome can serve as a biomarker for geographic origin inference, which has immense application value in forensic science.IMPORTANCEMicrobial communities in human hosts play a significant role in health and disease, varying in species, quantity, and composition due to factors such as gender, ethnicity, health status, lifestyle, and living environment. The characteristics of microbial composition at various body sites of individuals from different regions remain largely unexplored. This study utilized single-molecule real-time sequencing technology to detect the entire 16S rRNA gene of bacteria residing in the palmar skin, oral, and nasal cavities of Han individuals from four regions in China. The composition and structure of the bacteria at these three body sites were well characterized and found to differ regionally. The results elucidate the differences in bacterial communities colonizing these body sites across different regions and reveal the influence of geographical factors on human bacteria. These findings not only contribute to a deeper understanding of the diversity and geographical distribution of human bacteria but also enrich the microbiome data of the Asian population for further studies.

Human papillomavirus, vaginal microbiota and metagenomics: the interplay between development and progression of cervical cancer

Persistent infection with oncogenic human papillomavirus (HPV) types, such as HPV 16 or 18, is a major factor in cervical cancer development. However, only a small percentage of infected women develop cancer, indicating that other factors are involved. Emerging evidence links vaginal microbiota with HPV persistence and cancer progression. Alterations in microbial composition, function, and metabolic pathways may contribute to this process. Despite the potential of metagenomics to explore these interactions, studies on the vaginal microbiota's role in cervical cancer are limited. This review systematically examines the relationship between cervical microbiota, HPV, and cervical cancer by analyzing studies from PubMed, EBSCO, and Scopus. We highlight how microbial diversity influences HPV persistence and cancer progression, noting that healthy women typically have lower microbiota diversity and higher Lactobacillus abundance compared to HPV-infected women, who exhibit increased Gardenella, Prevotella, Sneathia, Megasphaera, Streptococcus, and Fusobacterium spp., associated with dysbiosis. We discuss how microbial diversity is associated with HPV persistence and cancer progression, noting that studies suggest healthy women typically have lower microbiota diversity and higher Lactobacillus abundance, while HPV-infected women exhibit increased Gardnerella, Prevotella, Sneathia, Megasphaera, Streptococcus, and Fusobacterium spp., indicative of dysbiosis. Potential markers such as Gardnerella and Prevotella have been identified as potential microbiome biomarkers associated with HPV infection and cervical cancer progression. The review also discusses microbiome-related gene expression changes in cervical cancer patients. However, further research is needed to validate these findings and explore additional microbiome alterations in cancer progression.

Oral microbiota: the overlooked catalyst in cancer initiation and progression

The advancement of high-throughput sequencing technology in recent decades has led to a greater understanding of the components of the oral microbiota, providing a solid foundation for extensive research in this field. The oral microbiota plays an important role in an individual's overall health. It has been shown to be significantly correlated with chronic human diseases, including diabetes, rheumatoid arthritis, cardiovascular disease, periodontal disease, and Alzheimer's disease. Furthermore, tumor occurrence and development are closely related to the oral microbiome. Specific bacteria, such as Fusobacterium nucleatum (F. nucleatum), Porphyromonas gingivalis (P. gingivalis), Streptococcus, Streptomyces, Prevotella, and Fibrophagy gingivalis, play critical roles in cancer development. The oral microbiota has various oncogenic mechanisms, including bacterial inflammation, immunological suppression, tumor growth mediated by bacterial toxins, antiapoptotic activity, and carcinogenic effects. This paper reviews the role of the oral microbiota in the occurrence and progression of cancer and systematically elucidates the molecular mechanisms by which dysbiosis influences tumorigenesis and tumor progression. This information can provide a theoretical basis for exploring cancer treatment strategies and offer new insights for cancer prevention.

The prevalence of motility-related genes within the human oral microbiota

The human oral and nasal microbiota contains approximately 770 cultivable bacterial species. More than 2,000 genome sequences of these bacteria can be found in the expanded Human Oral Microbiome Database (eHOMD). We developed HOMDscrape, a freely available Python software tool to programmatically retrieve and process amino acid sequences and sequence identifiers from BLAST results acquired from the eHOMD website. Using the data obtained through HOMDscrape, the phylogeny of proteins involved in bacterial type 9 secretion system (T9SS)-driven gliding motility, flagellar motility, and type IV pilus-driven twitching motility was constructed. A comprehensive phylogenetic analysis was conducted for all components of the rotary T9SS, a machinery responsible for secreting various enzymes, virulence factors, and enabling bacterial gliding motility. Results revealed that the T9SS outer membrane β-barrel protein SprA of human oral bacteria underwent horizontal evolution. Overall, we catalog motile bacteria that inhabit the human oral microbiota and document their evolutionary connections. These results will serve as a guide for further studies exploring the impact of motility on the shaping of the human oral microbiota.IMPORTANCEThe human oral microbiota has been extensively studied, and many of the isolated bacteria have genome sequences stored on the human oral microbiome database (eHOMD). Spatial distribution and polymicrobial biofilms are observed in the oral microbiota, but little is understood on how they are influenced by motility. To bridge this gap, we developed a software tool to identify motile bacteria from eHOMD. The results enabled the cataloging of motile bacteria present in the oral microbiota but also provided insight into their evolutionary relationships. This information can guide future research to better understand how bacterial motility shapes the human oral microbiota.

Metagenomic characterization of oral microbiome signatures to predict upper gastrointestinal and pancreaticobiliary cancers: a case-control study

BACKGROUND

This study investigated the oral microbiome signatures associated with upper gastrointestinal (GI) and pancreaticobiliary cancers.

METHODS

Saliva samples from cancer patients and age- and sex-matched healthy controls were analyzed using 16S rRNA-targeted sequencing, followed by comprehensive bioinformatics analysis.

RESULTS

Significant dissimilarities in microbial composition were observed between cancer patients and controls across esophageal cancer (EC), gastric cancer (GC), biliary tract cancer (BC), and pancreatic cancer (PC) groups (R2 = 0.067, = 0.075, = 0.068, and = 0.044; p = 0.001, = 0.001, = 0.002, and = 0.004, respectively). Additionally, the oral microbiome composition significantly differed by the four cancer sites (p = 0.001 for EC vs. GC, EC vs. BC, EC vs. PC, GC vs. BC, and GC vs. PC; p = 0.013 for BC vs. PC). We built oral metagenomic classifiers to predict cancer and selected specific microbial taxa with diagnostic properties. For EC, the classifier differentiated cancer patients and controls with good accuracy (area under the curve [AUC] = 0.791) and included three genera: Akkermansia, Escherichia-Shigella, and Subdoligranulum. For GC, the classifier exhibited high discriminative power (AUC = 0.961); it included five genera (Escherichia-Shigella, Gemella, Holdemanella, Actinomyces, and Stomatobaculum) and three species (Eubacterium sp. oral clone EI074, Ruminococcus sp. Marseille-P328, and Leptotrichia wadei F0279). However, microbial taxa with diagnostic features for BC and PC were not identified.

CONCLUSIONS

These findings suggested that the oral microbiome composition may serve as an indicator of tumorigenesis in upper GI and pancreaticobiliary cancers. The development of oral metagenomic classifiers for EC and GC demonstrates the potential value of microbial biomarkers in cancer screening.

Oral cancer immunology: state of the art and future perspectives

Oral cancer is a multifactorial disease involving genetic, epigenetic, and environmental factors. The literature indicates that inflammatory cells at the advancing front of the tumor induce a host immune response, preventing the spread of the tumor. However, cancer cells adopt various continued strategies to circumvent this immune surveillance. The complexity of immune mechanisms suggests that there must be virtually individual patterns of anti-tumor immune responses. Due to this important interaction of cancer with the immune system, the objective of the present study was to provide an up-to-date overview of immuno-oncology focused on oral cancer, summarizing the basic immunology, the classic risk factors, immunotherapy, and future treatment and prognostic perspectives.

ETS1 Promotes Aerobic Glycolysis and Growth in Head and Neck Squamous Cell Carcinoma by Targeting RRAS2

Head and neck squamous cell carcinoma (HNSCC) is a prevalent malignancy with a five-year survival rate below 50%, highlighting the urgent need for novel therapeutic targets. This study explores the role of the small GTPase RRAS2 in HNSCC progression and its regulation of glycolysis. Analysis of data from the TCGA and GTEx databases revealed that RRAS2 is significantly upregulated in HNSCC tissues and is associated with poorer overall patient survival. Functional experiments demonstrated that silencing RRAS2 in HNSCC cell lines inhibits glycolytic activity and cell proliferation while promoting apoptosis, whereas overexpression of RRAS2 enhances glycolysis and cell growth. Additionally, bioinformatics and experimental approaches identified the transcription factor ETS1 as an upstream regulator of RRAS2. ETS1 binds to the RRAS2 promoter, facilitating its transcription and contributing to metabolic reprogramming in HNSCC cells. Rescue experiments confirmed that the ETS1-RRAS2 axis is crucial for maintaining the glycolytic phenotype and proliferative capacity of HNSCC cells. These findings suggest that the ETS1-RRAS2 pathway plays a critical role in HNSCC progression and metabolic adaptation, positioning RRAS2 as a potential therapeutic target for improving patient outcomes.

Oral Pathogens' Substantial Burden on Cancer, Cardiovascular Diseases, Alzheimer's, Diabetes, and Other Systemic Diseases: A Public Health Crisis-A Comprehensive Review

This review synthesizes the findings from 252 studies to explore the relationship between the oral pathogens associated with periodontitis, dental caries, and systemic diseases. Individuals with oral diseases, such as periodontitis, are between 1.7 and 7.5 times (average 3.3 times) more likely to develop systemic diseases or suffer adverse pregnancy outcomes, underscoring the critical connection between dental and overall health. Oral conditions such as periodontitis and dental caries represent a significant health burden, affecting 26-47% of Americans. The most important oral pathogens, ranked by publication frequency, include the herpes virus, C. albicans, S. mutans, P. gingivalis, F. nucleatum, A. actinomycetemcomitans, P. intermedia, T. denticola, and T. forsythia. The systemic diseases and disorders linked to oral infections, ranked similarly, include cancer, respiratory, liver, bowel, fever, kidney, complications in pregnancy, cardiovascular bacteremia, diabetes, arthritis, autoimmune, bladder, dementia, lupus, and Alzheimer's diseases. Evidence supports the efficacy of dental and periodontal treatments in eliminating oral infections and reducing the severity of systemic diseases. The substantial burden that oral pathogens have on cancer, cardiovascular diseases, Alzheimer's, diabetes, and other systemic diseases poses a significant public health crisis.

Oral Microbiome Research in Biopsy Samples of Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma and Its Challenges

This study aims to evaluate the potential benefits and challenges of integrating oral microbiome research into the clinical management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC). The oral microbiome has gained significant attention for its role in the pathogenesis and progression of these conditions, with emerging evidence suggesting its value as a diagnostic and prognostic tool. By critically analyzing current evidence and methodological considerations, this manuscript examines whether microbiome analysis in biopsy samples can aid in the early detection, prognosis, and management of OPMD and OSCC. The complexity and dynamic nature of the oral microbiome require a multifaceted approach to fully understand its clinical utility. Based on this review, we conclude that studying the oral microbiome in this context holds significant promise but also faces notable challenges, including methodological variability and the need for standardization. Ultimately, this manuscript addresses the question, “Should such research be undertaken, given the intricate interactions of various factors and the inherent obstacles involved?”, and also emphasizes the importance of further research to optimize clinical applications and improve patient outcomes.

Potential Antimicrobial and Cytotoxic Activity of Caralluma indica Seed Extract

Background: Plant-derived phytochemicals are crucial in fighting bacterial infections and in cancer therapy. Objective: This study investigates the phytochemical composition of the ethanolic extract obtained from Caralluma indica (C. indica) seeds and assesses its antimicrobial, anticancer, and antioxidant activities. Results: GC-MS analysis found 30 phytochemicals in C. indica seeds, including 5 bioactive compounds that have been shown to have antioxidant, antimicrobial, and cytotoxicity properties, through in silico evaluation. Phytochemical screening of C. indica identified and measured the phenolic compounds, providing insight into its bioactive potential and therapeutic properties. C. indica exhibited robust antioxidant capacity (DPPH, ABTS, nitric oxide, and H2O2 radical scavenging) alongside potent antimicrobial activity against oral pathogen and cytotoxicity activity on a human oral squamous carcinoma cell line (OECM-1) (EC50 of 169.35 µg/mL) and yeast cell Saccharomyces cerevisiae (215.82 µg/mL), with a selective index of 1.27. The subminimum % MBC/MFC of C. indica significantly reduced biofilm formation against oral pathogens (p < 0.05). Molecular docking studies showed a strong correlation (r = 0.862) between antifungal and anticancer targets, suggesting that the antimicrobial agents in C. indica contribute to cancer prevention mechanisms. Conclusions: These findings propose C. indica seeds as promising candidates for combating oral pathogens, inhibiting biofilm formation, and reducing the risk of oral cancer progression.

Advances in nanotechnology-based approaches for the treatment of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), one of the most common types of cancers occurring in the head and neck region, is often associated with high mortality rates due to its invasiveness and morbidity. The mainstream treatment methods in clinical settings, including surgery, chemotherapy, and radiotherapy, may cause poor overall survival rate and prognosis, with issues such as drug resistance, damage to adjacent healthy tissues, and potential recurrences. Other treatment approaches such as immunotherapy, photodynamic therapy (PDT), and photothermal therapy (PPT) also suffer from inefficient tumor targeting and suboptimal therapeutic outcomes. Early detection is vital for HNSCC patients, but it is always limited by insensitivity and confusing clinical manifestations. Hence, it is highly desirable to develop optimized therapeutic and diagnostic strategies. With the boom in nanomaterials, nanotechnology-conducted HNSCC therapy has attracted widespread attention. Nanoparticles (NPs) are distinguished by their unique morphology and superior physicochemical property, and some can exhibit direct antitumor activity, while others serve as promising candidates for drug delivery. In addition, NPs offer the potential for structural modification for drug delivery and tumor targeting, enabling specific delivery to tumor cells through conjugation with biomarker ligands and improving cargo biocompatibility. This work reviews current therapies and diagnosis methods for HNSCC, highlights the characteristics of the major NPs, surveys their uses and advantages in the treatment of HNSCC, and discusses the obstacles and prospects in clinical applications, aiming to enlighten future research directions for nanotechnology-based therapy for HNSCC.

The oral-gut microbiome axis in health and disease

The human body hosts trillions of microorganisms throughout many diverse habitats with different physico-chemical characteristics. Among them, the oral cavity and the gut harbour some of the most dense and diverse microbial communities. Although these two sites are physiologically distinct, they are directly connected and can influence each other in several ways. For example, oral microorganisms can reach and colonize the gastrointestinal tract, particularly in the context of gut dysbiosis. However, the mechanisms of colonization and the role that the oral microbiome plays in causing or exacerbating diseases in other organs have not yet been fully elucidated. Here, we describe recent advances in our understanding of how the oral and intestinal microbiota interplay in relation to their impact on human health and disease.

The oncomicrobiome: New insights into microorganisms in cancer

The discoveries of the oncomicrobiome (intratumoral microbiome) and oncomicrobiota (intratumoral microbiota) represent significant advances in tumor research and have rapidly become of key interest to the field. Within tumors, microorganisms such as bacteria, fungi, viruses, and archaea form the oncomicrobiota and are primarily found within tumor cells, immunocytes, and the intercellular matrix. The oncomicrobiome exhibits marked heterogeneity and is associated with tumor initiation, progression, metastasis, and treatment response. Interactions between the oncomicrobiome and the immune system can modulate host antitumor immunity, influencing the efficacy of immunotherapies. Oncomicrobiome research also faces numerous challenges, including overcoming methodological issues such as low target abundance, susceptibility to contamination, and biases in sample handling and analysis methods across different studies. Furthermore, studies of the oncomicrobiome may be confounded by baseline differences in microbiomes among populations driven by both environmental and genetic factors. Most studies to date have revealed associations between the oncomicrobiome and tumors, but very few have established mechanistic links between the two. This review introduces the relevant concepts, detection methods, sources, and characteristics of the oncomicrobiome. We then describe the composition of the oncomicrobiome in common tumors and its role in shaping the tumor microenvironment. We also discuss the current problems and challenges to be overcome in this rapidly progressing field.

Glycans in the oral bacteria and fungi: Shaping host-microbe interactions and human health

The human oral cavity serves as the natural entry port to both the gastrointestinal and respiratory tracts, and hosts a diverse microbial community essential for maintaining health. Dysbiosis of this microbiome can lead to various diseases. Glycans, as vital carriers of biological information, are indispensable structural components of living organisms and play key roles in numerous biological processes. In the oral microbiome, glycans influence microbial binding to host receptors, promote colonization, and mediate communication among microbial communities, as well as between microbes and the host immune system. Targeting glycans may provide innovative strategies for modulating the composition of the oral microbiome, with broader implications for human health. Additionally, exogenous glycans regulate the oral microbiome by serving as carbon and energy sources for microbes, while certain specific glycans can inhibit microbial growth and activity. This review summarizes glycosylation pathways in oral bacteria and fungi, explores the regulation of host-microbiota interactions by glycans, and discusses the effects of exogenous glycans on oral microbiome. The review aims to highlight the multifaceted role of glycans in shaping the oral microbiome and its impact on the host, while also indicates potential future applications.

Transcriptome Analysis of HNSCC by Aggregatibacter actinomycetemcomitans Extracellular Vesicles

OBJECTIVES

The role of extracellular vesicles (EVs), also known as outer membrane vesicles (OMVs), secreted by oral bacteria in the progression of head and neck squamous cell carcinomas (HNSCCs), is largely unexplored. This study aimed to investigate the influence of bacterial EVs, specifically those derived from Aggregatibacter actinomycetemcomitans (Aa), on the progression of HNSCC.

MATERIALS AND METHODS

FaDu and UMSCC1 cell lines were treated with Aa-derived EVs, and oncogenic activities were assessed. Comprehensive cellular and RNA-sequencing transcriptome analyses were conducted to assess the impact of these EVs on cell cycle progression and gene expression.

RESULTS

Our findings reveal that Aa-derived EVs accelerate cell cycle progression through the S and G2 phases and enhance invasion in HNSCC cell lines. RNA-sequencing analysis showed that Aa-derived EVs exert a more significant effect on general transcript expression than on microRNA profiles, except for miR-146a, which is recognized as a key factor in both carcinogenesis and immune modulation.

CONCLUSIONS

Bacterial EVs, particularly from periodontal pathogens like Aa, are significant modulators within the oral cancer environment, potentially affecting cellular behavior and gene expression profiles. This study highlights the complex relationship between periodontal health and oral carcinogenesis, emphasizing the significant role of bacterial EVs in HNSCC progression.

Assessing the oral microbiome of head and neck cancer patients before and during radiotherapy

OBJECTIVE

To characterize the oral microbiome of patients with head and neck squamous cell carcinoma (HNSCC) before and during radiotherapy (RT), compared to healthy individuals. Evaluating the impact of oral microbiome in the clinical outcomes one year following the end of RT.

METHODS

Oral samples were collected from HNSCC patients who underwent RT using the following regimens: no dose received (T0), dose 12-16 Gy (T1), dose 30-36 Gy (T2) and dose ≥ 60 Gy (T3). Samples from healthy individuals were also collected only once as a control group. Regions V1-V2 of the 16S rRNA were sequenced by Illumina and analyzed using Mothur.

RESULTS

49 patients with HNSCC and 25 healthy individuals were included. At T0, HNSCC patients showed a lower abundance of Firmicutes and Streptococcus (p = 0.011, p = 0.002) and a higher abundance of Bacteroidetes (p = 0.005) compared to healthy individuals. During RT, Fusobacterium (p = 0.017) and Porphyromonas (p = 0.0008) decreased, while Streptococcus increased at T1 (p = 0.001). By T3, the differences in Firmicutes, Bacteroidetes, and Streptococcus between the control and HNSCC groups were no longer significant (p > 0.3). Patients with higher initial abundances of Porphyromonas (p = 0.012) and Fusobacterium (p = 0.017) had poorer outcomes, including recurrence, metastasis, and death. In contrast, disease-free patients had a higher abundance of Streptococcus (p = 0.004).

CONCLUSION

Oral microbiome dysbiosis was found in HNSCC patients. By the end of RT, the main initial differences in phylum and genus abundance observed at T0 between the control and HNSCC groups were no longer present. Higher abundances of Fusobacterium and Porphyromonas were associated with poor outcomes.

The oral microbiome of children in health and disease-a literature review

The oral microbiome is a complex community of microorganisms residing in the oral cavity interacting with each other and with the host in a state of equilibrium. Disruptions in this balance can result in both oral and systemic conditions. Historically, studying the oral microbiome faced limitations due to culture-dependent techniques that could not capture the complexity and diversity of the microbial community. The emergence of advanced genomic technologies and the ease of sample collection from the oral cavity has revolutionized the understanding of the oral microbiome, providing valuable insights into the bacterial community in both health and disease. This review explores the oral microbiome in children, discussing its formation and dynamics in both states of health and disease, its role in various conditions such as dental caries, periodontal disease, oral cancer, cleft lip and palate, and explores its connection to several systemic consequences.

Analysis of Risk Factors with Assessment of the Impact of the Microbiome on the Risk of Squamous Cell Carcinoma of the Larynx

Introduction: Head and neck squamous cell carcinoma (HNSCC) ranks sixth among cancers in the world, and the 5-year survival rate ranges from 25% to 60%. The risk factors for HNSCC are primarily smoking, alcohol consumption and human papillomavirus (HPV). Data indicate that 15-20% of cancers are caused by infectious agents, 20-30% by smoking and 30-35% by unhealthy lifestyles, diet, lack of physical activity and obesity. Dysbiosis is a microbiome imbalance, which promotes oncogenesis by intensifying inflammatory processes and affecting the host's metabolism. Profiling the microbiome in various types of cancer is currently the subject of research and analysis. However, there is still little information on the correlation of the microbiome with HNSCC and its impact on oncogenesis, the course of the disease and its treatment. Objective: The aim of the study was to prospectively assess risk factors with assessment of the impact of the microbiome on the risk of squamous cell carcinoma of the larynx. The study included a group of 44 patients diagnosed with squamous cell carcinoma of the larynx and 30 patients from the control group. Results: In the control group, bacteria of the normal microbiome dominated-the genus Streptococcus, Gemella, Neisseria and Kingella. In the group of patients with laryngeal cancer, Prevotella, Clostridiales and Stomatobaculum were found significantly more often. Porphyromonas, Fusobacterium, Lactobacillus, Actinobacteria, Actinomyces and Shaalia odontolytica were also found at a higher percentage in the study group. Analyzing the phylum, Firmicutes dominated in the control group; there were statistically significantly more of them than in patients from the study group. Bacteroides and Bacillota were found significantly more often in patients with laryngeal cancer. Conclusions: The importance of the microbiome in oncology has been confirmed in many studies. Independent risk factors for laryngeal cancer were primarily a lower number of Firmicutes in the microbiome, but also an increased leukocyte level above 6.52 × 103/mm and a decreased total protein level below 6.9 g/dL. Prevotella, Clostridiales, Stomatobaculum, Porphyromonas, Fusobacterium, Lactobacillus, Actinobacteria, Actinomyces and Shaalia were considered to be the bacteria contributing to the development of laryngeal cancer. Streptococcus, Gemella, Neisserie and Kingella were considered to be protective bacteria. Moreover, the study confirmed the significant impact of smoking, alcohol consumption and poor oral hygiene on the development of laryngeal cancer. The microbiome, its identification and manipulation may constitute a breakthrough discovery for improving the diagnosis and oncological therapy of laryngeal cancer, and also of the entire group of HNSCC. Profiling the microbiome may allow for personalized therapy related to its modification. Assessing the microbiome of patients diagnosed with cancer may provide an opportunity to predict treatment response and effectiveness.

Metagenomic Study Reveals Phage-Bacterial Interactome Dynamics in Gut and Oral Microbiota in Pancreatic Diseases

Individuals with pancreatic-related health conditions usually show lower diversity and different composition of bacterial and viral species between the gut and oral microbiomes compared to healthy individuals. We performed a thorough microbiome analysis, using deep shotgun sequencing of stool and saliva samples obtained from patients with chronic pancreatitis (CP), pancreatic ductal adenocarcinoma (PDAC), and healthy controls (HCs).We observed similar microbiota composition at the species level in both the gut and oral samples in PDAC patients compared to HCs, among which the most distinctive finding was that the abundance of oral-originated Fusobacterium nucleatum species did not differ between the oral and the gut samples. Moreover, comparing PDAC patients with HCs, Klebsiella oxytoca was significantly more abundant in the stool samples of PDAC patients, while Streptococcus spp. showed higher abundance in both the oral and stool samples of PDAC patients. Finally, the most important finding was the distinctive gut phage-bacterial interactome pattern among PDAC patients. CrAssphages, particularly Blohavirus, showed mutual exclusion with K. oxytoca species, while Burzaovirus showed co-occurrence with Enterobacteriaceae spp., which have been shown to be capable of inducing DNA damage in human pancreatic cells ex vivo. The interactome findings warrant further mechanistic studies, as our findings may provide new insights into developing microbiota-based diagnostic and therapeutic methods for pancreatic diseases.

Oral Microbiome and CPT1A Function in Fatty Acid Metabolism in Oral Cancer

The oral microbiome is crucial for human health. Although oral dysbiosis may contribute to oral cancer (OC), the detailed relationships between the microbiome and OC remain unclear. In this case-control study, we aimed to elucidate the connection between the oral microbiome and mechanisms potentially involved in oral cancer. The study analyzed 1022 oral saliva samples, including 157 from oral cancer patients and 865 from healthy controls, using 16S ribosomal RNA (16S rRNA) sequencing and a Light Gradient Boosting Machine (LightGBM) model to identify four bacterial genera significantly associated with oral cancer. In patients with oral cancer, the relative abundance of Streptococcus and Parvimonas was higher; Corynebacterium and Prevotella showed decreased relative abundance; and levels of fatty acid oxidation enzymes, including Carnitine palmitoyltransferase 1A (CPT1A), long-chain acyl-CoA synthetase, acyl-CoA dehydrogenase, diacylglycerol choline phosphotransferase, and H+-transporting ATPase, were significantly higher compared to controls. Conversely, healthy controls exhibited increased levels of short-chain fatty acids (SCFAs) and CD4+T-helper cell counts. Survival analysis revealed that higher abundance of Streptococcus and Parvimonas, which correlated positively with interleukin-6, tumor necrosis factor-alpha, and CPT1A, were linked to poorer disease-free survival (DFS) and overall survival (OS) rates, while Prevotella and Corynebacterium were associated with better outcomes. These findings suggest that changes in these bacterial genera are associated with alterations in specific cytokines, CPT1A levels, SCFAs in oral cancer, with lower SCFA levels in patients reinforcing this link. Overall, these microbiome changes, along with cytokine and enzyme alterations, may serve as predictive markers, enhancing diagnostic accuracy for oral cancer.

Assessment of Prognostic Factors, Clinical Features Including the Microbiome, and Treatment Outcomes in Patients with Cancer of Unknown Primary Site

INTRODUCTIONS

cancer of unknown primary site (CUP) is a heterogeneous group of cancers in which metastases are found, and the primary tumor is not detected with available diagnostic methods. CUP is a disease that has not been fully researched, and its biology is unclear. The clinical characteristics of CUP are variable, but the prognosis of patients is usually unfavorable, and the possibilities of radical treatment are limited. The microbiome is the genes and gene products of microorganisms residing in a human body. In recent years, thanks to the use of next-generation sequencing, it is possible to assess the impact of the microbiome on human body functions. Head and neck cancers, due to the rich microbiome of this area, are influenced by it, and dysbiosis may be a risk factor for the development of cancer. Objective of this work: the aim of this study was to evaluate prognostic factors, clinical features including the microbiome, and treatment outcomes in patients with cancer of unknown primary site.

RESULTS

in the study group, increased numbers of bacteria of the phyla Bacteroides, Fusobacteria, Bacillota, Actinomycetota, Actinobacteria, and Candidatus were detected, while Firmicutes and Proteobacteria were detected in smaller numbers. Independent predictors of CUP occurrence were the following: leukocyte count of at most 6.49 × 103/mm, bacteria from the Proteobacteria phylum in the microbiome below 11.6%, Firmicutes below 22.1%, and Actinobacteria at least 11.0%. Increased numbers of Porphyromonas and Fusobacterium bacteria were associated with the risk of radiotherapy complications and shortened survival rate.

CONCLUSIONS

clinical diagnosis and treatment of patients with CUP is complicated and difficult due to the lack of consensus on this issue. Treatment and prognosis of patients with CUP is unsatisfactory. The clinical value of the influence of the microbiome on the development, course, and treatment of cancer is becoming increasingly important. The microbiome may become a marker of response to anticancer treatment and the risk of its complications. Immunity modulation with the microbiome provides opportunities for further research on improving the effectiveness of oncological treatment. Fusobacterium and Porphyromonas seem to be the bacteria most important for the development of cancer, also worsening the prognosis of patients by increasing the risk of complications of radiotherapy and shortening the survival rate of patients. Streptococcus and Lactobacillus seem to be bacteria that reduce the risk of cancer, reduce the risk of complications, and improve the prognosis of patients. Total protein deficiency and elevated inflammatory markers are also important predictors of cancer risk.

Beyond the Gut: The intratumoral microbiome's influence on tumorigenesis and treatment response

The intratumoral microbiome (TM) refers to the microorganisms in the tumor tissues, including bacteria, fungi, viruses, and so on, and is distinct from the gut microbiome and circulating microbiota. TM is strongly associated with tumorigenesis, progression, metastasis, and response to therapy. This paper highlights the current status of TM. Tract sources, adjacent normal tissue, circulatory system, and concomitant tumor co-metastasis are the main origin of TM. The advanced techniques in TM analysis are comprehensively summarized. Besides, TM is involved in tumor progression through several mechanisms, including DNA damage, activation of oncogenic signaling pathways (phosphoinositide 3-kinase [PI3K], signal transducer and activator of transcription [STAT], WNT/β-catenin, and extracellular regulated protein kinases [ERK]), influence of cytokines and induce inflammatory responses, and interaction with the tumor microenvironment (anti-tumor immunity, pro-tumor immunity, and microbial-derived metabolites). Moreover, promising directions of TM in tumor therapy include immunotherapy, chemotherapy, radiotherapy, the application of probiotics/prebiotics/synbiotics, fecal microbiome transplantation, engineered microbiota, phage therapy, and oncolytic virus therapy. The inherent challenges of clinical application are also summarized. This review provides a comprehensive landscape for analyzing TM, especially the TM-related mechanisms and TM-based treatment in cancer.

Immunomodulatory effects of Triphala and its constituents in oral squamous cell carcinoma and oral precancer

Oral squamous cell carcinoma shows increased occurrence in those who consume tobacco products, alcohol, betel quid, and areca nut, and is also considered to occur due to genetic alteration. Though there are numerous advancements in treatment, survival remains a question with late diagnosis. Hence, there are continuous inventions of new drugs. The introduction of Ayurveda in the therapy has paved the way for the longevity of the patients affected. One such introduction is the use of Triphala. The current study aims to review the anti-oxidant, anti-proliferative, anti-microbial, and apoptotic action of Triphala and thus evaluate the anti-cancer action of Triphala. A literature search was done, in various electronic databases and the data were extracted according to the predefined criteria. Original studies of 19 reports were included in the analysis. Nineteen (six studies with Triphala combination) In vitro/In vivo studies were included in this systematic review. The included study showed that Triphala effectively modulates the immune system. The effects included were anti-oxidative, immune modulation, anti-proliferative, tumor suppression, apoptotic effect, reversal of precancerous lesion, and anti-microbial action. The analyses also showed that there is no side effect of Triphala up to the recommended dosage. Triphala, is a nourishing supplement that is well-known in Ayurveda for its capacity to restore healthy tissues and promote aging gracefully through its properties such as anti-oxidant, ant-proliferative, anti-inflammatory, cytotoxic apoptotic, and immune-modulatory properties. Hence, Triphala can be a promising drug in the prevention and treatment of oral cancer.

Periodontal pathogens and cancer development

Increasing evidence suggests a significant association between periodontal disease and the occurrence of various cancers. The carcinogenic potential of several periodontal pathogens has been substantiated in vitro and in vivo. This review provides a comprehensive overview of the diverse mechanisms employed by different periodontal pathogens in the development of cancer. These mechanisms induce chronic inflammation, inhibit the host's immune system, activate cell invasion and proliferation, possess anti-apoptotic activity, and produce carcinogenic substances. Elucidating these mechanisms might provide new insights for developing novel approaches for tumor prevention, therapeutic purposes, and survival improvement.

Is Short-Read 16S rRNA Sequencing of Oral Microbiome Sampling a Suitable Diagnostic Tool for Head and Neck Cancer?

The oral microbiome, studied by sampling the saliva or by oral rinse, has been long thought to have diagnostic capacity for head and neck cancers (HNC). However, previous reports on the HNC oral microbiome provide inconsistent results. The aim of this study is to consolidate these datasets and determine the oral microbial composition between HNC patients to healthy and premalignant individuals. We analyzed 16 published head and neck cancer (HNC) short-read 16S rRNA sequencing datasets, specifically targeting the V3V4, V4 and V4V5 regions. These datasets included saliva and oral rinse samples from donors with HNC, as well as from healthy and premalignant donors. Differences in diversities and microbial abundance were determined. HNC saliva displayed lower alpha diversity than healthy donors. In contrast, the opposite trend was observed for oral rinse samples. Beta diversity scores were largely similar across different patient types. Similar oral phyla were detected for all samples, but proportions were largely dependent on sample type (i.e., saliva or oral rinse) and primer set utilized for 16S rRNA sequencing. Neisseria, Leptotrichia and Megasphaera were elevated in healthy saliva, while Mycoplasma was elevated in HNC saliva. Oral rinse and saliva displayed similar enrichment for Fusobacterium, while Veillonella, Alloprevotella, and Campylobacter showed conflicting results. The sparse partial least squares discriminant analysis model performed effectively in discriminating HNC from healthy or premalignant patients using V3V4 saliva (AUC = 0.888) and V3V4 oral rinse (AUC = 0.928), while poor discriminative capacity was observed for V4 saliva (AUC = 0.688). In conclusion, our meta-analysis highlighted the limitations of 16S rRNA sequencing, particularly due to variations across study batches, primer sets (i.e., V3V4, V4), and sample types. Hence, caution should be exercised when interpreting 16S rRNA sequencing results across studies, especially when different primer sets and sample types are used.

Altered microbial diversity and composition of multiple mucosal organs in cervical cancer patients

OBJECTIVES

The aim of this study was to characterize the microbiome of multiple mucosal organs in cervical cancer (CC) patients.

METHODS

We collected oral, gut, urinary tract, and vaginal samples from enrolled study participants, as well as tumor tissue from CC patients. The microbiota of different mucosal organs was identified by 16S rDNA sequencing and correlated with clinical-pathological characteristics of cervical cancer cases.

RESULTS

Compared with controls, CC patients had reduced α-diversity of oral and gut microbiota (pOral_Sob < 0.001, pOral_Shannon = 0.049, pOral_Simpson = 0.013 pFecal_Sob = 0.030), although there was an opposite trend in the vaginal microbiota (pVaginal_Pielou = 0.028, pVaginal_Simpson = 0.006). There were also significant differences in the β-diversity of the microbiota at each site between cases and controls (pOral = 0.002, pFecal = 0.037, pUrine = 0.001, pVaginal = 0.001). The uniformity of urine microbiota was lower in patients with cervical squamous cell carcinoma (pUrine = 0.036) and lymph node metastasis (pUrine_Sob = 0.027, pUrine_Pielou = 0.028, pUrine_Simpson = 0.021, pUrine_Shannon = 0.047). The composition of bacteria in urine also varied among patients with different ages (p = 0.002), tumor stages (p = 0.001) and lymph node metastasis (p = 0.002). In CC cases, Pseudomonas were significantly enriched in the oral, gut, and urinary tract samples. In addition, Gardnerella, Anaerococcus, and Prevotella were biomarkers of urinary tract microbiota; Abiotrophia and Lautropia were obviously enriched in the oral microbiota. The microbiota of tumor tissue correlated with other mucosal organs (except the gut), with a shift in the microflora between mucosal organs and tumors.

CONCLUSIONS

Our study not only revealed differences in the composition and diversity of the vaginal and gut microflora between CC cases and controls, but also showed dysbiosis of the oral cavity and urethra in cervical cancer cases.

Defining intra-tumoral and systemic immune biomarkers for locally advanced head-and-neck cancer - detailed protocol of a prospective, observatory multicenter trial (ImmunBioKHT) and first results of the immunophenotyping of the patients' peripheral blood

The approval and effectiveness of immune checkpoint inhibitors in head-and-neck squamous cell carcinoma (HNSCC) highlights the role of the immune system in this tumor entity. HNSCCs not only interacts with the immune system in the tumor tissue, but also induce systemic effects that may be additionally influenced by further factors such as the microbiome. Nonetheless, reliable immunological biomarkers that predict treatment response and outcome in HNSCC patients are lacking. The currently available biomarkers are mainly limited to analyses from tumor biopsies, while biomarkers from liquid biopsies, such as peripheral blood are not well-established. Thus, the here presented trial aims to identify interactions of intra-tumoral and systemic immune responses and to define prognostic immune signatures. Consequently, not only samples from the tumor tissue, but also from peripheral blood and the microbiome will be studied/are being evaluated and correlated with the clinical outcome. In this prospective, multi-center trial, 1000 HNSCC patients and 100 patients in the control cohort with non-tumor head-and-neck surgery will be enrolled. The local immune status from of the tumor and the microbiome will be sampled before treatment. In addition, the systemic immune status from peripheral blood will be analyzed before and after surgery and after the adjuvant and definitive radio-chemotherapy (RCT). Clinical baseline characteristics and outcome will additionally be collected. Data mining and modelling approaches will finally be applied to identify interactions of local and systemic immune parameters and to define prognostic immune signatures based on the evaluated immune markers. Approval from the institutional review board of the Friedrich-Alexander-Universität Erlangen-Nürnberg was granted in December 2021 (application number 21-440-B). By now, 150 patients have been enrolled in the intervention cohort. The results will be disseminated to the scientific audience and the general public via presentations at conferences and publication in peer-reviewed journals.

Influence of microbiome in intraprostatic inflammation and prostate cancer

BACKGROUND

Chronic infection and inflammation have been linked to the development of prostate cancer. Dysbiosis of the oral and gut microbiomes and subsequent microbial translocation can lead to pathogenic prostate infections. Microbial-produced metabolites have also been associated with signaling pathways that promote prostate cancer development. A comprehensive discussion on the mechanisms of microbiome infection and the prostate microenvironment is essential to understand prostate carcinogenesis.

METHODS

Published studies were used from the National Center for Biotechnology Information (NCBI) database to conduct a narrative review. No restrictions were applied in the selection of articles.

RESULTS

Microbiome-derived short-chain fatty acids (SCFAs) have been found to upregulate multiple signaling pathways, including MAPK and PI3K, through IGF-1 signaling and M2 macrophage polarization. SCFAs can also upregulate Toll-like receptors, leading to chronic inflammation and the creation of a pro-prostate cancer environment. Dysbiosis of oral microbiota has been correlated with prostate infection and inflammation. Additionally, pathogenic microbiomes associated with urinary tract infections have shown a link to prostate cancer, with vesicoureteral reflux potentially contributing to prostate infection.

CONCLUSIONS

This review offers a comprehensive understanding of the impact of microbial infections linked to intraprostatic inflammation as a causative factor for prostate cancer. Further studies involving the manipulation of the microbiome and its produced metabolites may provide a more complete understanding of the microenvironmental mechanisms that promote prostate carcinogenesis.

The Impact of Oral Microbiome Dysbiosis on the Aetiology, Pathogenesis, and Development of Oral Cancer

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. Although the oral cavity is an easily accessible area for visual examination, the OSCC is more often detected at an advanced stage. The global prevalence of OSCC is around 6%, with increasing trends posing a significant health problem due to the increase in morbidity and mortality. The oral cavity microbiome has been the target of numerous studies, with findings highlighting the significant role of dysbiosis in developing OSCC. Dysbiosis can significantly increase pathobionts (bacteria, viruses, fungi, and parasites) that trigger inflammation through their virulence and pathogenicity factors. In contrast, chronic bacterial inflammation contributes to the development of OSCC. Pathobionts also have other effects, such as the impact on the immune system, which can alter immune responses and contribute to a pro-inflammatory environment. Poor oral hygiene and carbohydrate-rich foods can also increase the risk of developing oral cancer. The risk factors and mechanisms of OSCC development are not yet fully understood and remain a frequent research topic. For this reason, this narrative review concentrates on the issue of dysbiosis as the potential cause of OSCC, as well as the underlying mechanisms involved.

The hidden link: How oral and respiratory microbiomes affect multiple sclerosis

BACKGROUND

Extensive research has explored the role of gut microbiota in multiple sclerosis (MS). However, the impact of microbial communities in the oral cavity and respiratory tract on MS is an emerging area of investigation.

PURPOSE

We aimed to review the current literature related to the nasal, oral, and lung microbiota in people with MS (PwMS).

METHODS

We conducted a narrative review of clinical and preclinical original studies on PubMed that explored the relationship between the bacterial or viral composition of the nasal, lung, and oral microbiota and MS. Additionally, to find relevant studies not retrieved initially, we also searched for references in related review papers, as well as the references cited within the included studies.

RESULTS AND CONCLUSIONS

Thirteen studies were meticulously reviewed in three sections; oral microbiota (n = 8), nasal microbiota (n = 3), and lung microbiota (n = 2), highlighting considerable alterations in the oral and respiratory microbiome of PwMS compared to healthy controls (HCs). Genera like Aggregatibacter and Streptococcus were less abundant in the oral microbiota of PwMS compared to HCs, while Staphylococcus, Leptotrichia, Fusobacterium, and Bacteroides showed increased abundance in PwMS. Additionally, the presence of specific bacteria, including Streptococcus sanguinis, within the oral microbiota was suggested to influence Epstein-Barr virus reactivation, a well-established risk factor for MS. Studies related to the nasal microbiome indicated elevated levels of specific Staphylococcus aureus toxins, as well as nasal glial cell infection with human herpes virus (HHV)-6 in PwMS. Emerging research on lung microbiome in animal models demonstrated that manipulating the lung microbiome towards lipopolysaccharide-producing bacteria might suppress MS symptoms. These findings open avenues for potential therapeutic strategies. However, further research is crucial to fully understand the complex interactions between the microbiome and MS. This will help identify the most effective timing, bacterial strains, and modulation techniques.

Oral microbiome and its relationship with oral cancer

ABSTRACT

As the initial point for digestion, the balance of oral microorganisms plays an important role in maintaining local and systemic health. Oral dysbiosis, or an imbalance in the oral microbial community, may lead to the onset of various diseases. The presence or abnormal increase of microbes in the oral cavity has attracted significant attention due to its complicated relationship with oral cancer. Oral cancer can remodel microbial profiles by creating a more beneficial microenvironment for its progression. On the other hand, altered microbial profiles can promote tumorigenesis by evoking a complex inflammatory response and affecting host immunity. This review analyzes the oncogenic potential of oral microbiome alterations as a driver and biomarker. Additionally, a potentially therapeutic strategy via the reversal of the oral microbiome dysbiosis in oral cancers has been discussed.

The Effects of Nicotine Pouches and E-Cigarettes on Oral Microbes: A Pilot Study

It remains uncertain whether nicotine pouches and electronic cigarettes alter the oral environment and result in a high presence of periodontopathogenic bacteria in saliva, compared to that among cigarette users or non-tobacco users. In this study, saliva samples were collected from respondents using nicotine pouches, electronic cigarettes, and conventional cigarettes, alongside a control group of non-tobacco users. Polymerase chain reaction was used to identify clinical isolates of the following periodontal bacteria: Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Fusobacterium nucleatum, Fusobacterium periodonticum, Porphyromonas endodontalis, and Rothia mucilaginosa. The presence of some periodontal pathogens was detected in the saliva samples from users of nicotine pouches, electronic cigarettes, and conventional cigarettes but not in samples taken from the control group. Therefore, the initial results of this pilot study suggest that the presence of periodontopathogenic bacteria in the saliva of nicotine pouch and electronic cigarette users could alter the oral microbiome, leading to periodontal diseases. However, further quantitative investigation is needed.

Aggregatibacter actinomycetemcomitans: From the Oral Cavity to the Heart Valves

Aggregatibacter actinomycetemcomitans (A. actinomycetecomitans) is a Gram-negative bacterial species that is an essential component of the oral microbiota. Due to its aggregative properties, it plays a role in the pathogenesis of human diseases. The presence of the surface proteins Fim, Briae, and microvesicles enables the bacterium to adhere to the epithelial surface and the tooth's surface. The presence of leukotoxin A (LtxA), which plays an important role in the pathogenicity of the bacterium, has been associated with both periodontitis and the etiology of rheumatoid arthritis (RA). A. actinomycetecomitans is also associated with several other systemic diseases and complications, such as endocarditis and different abscesses. In addition to leukotoxin A, A. actinomycetecomitans possesses several different virulence factors, including bacteriocins, chemotaxis inhibitory factors, cytotoxic factors, Fc-binding proteins, immunosuppressive factors, lipopolysaccharide collagenase, fibroblast inhibitory factors, antibiotic resistance determinants, adhesins, invasive factors and factors that inhibit the function of polymorphonuclear leukocytes. The ability of A. actinomycetemcomitans lipopolysaccharide to induce macrophages to secrete the interleukins IL-1, IL-1β, and tumor necrosis factor (TNF) is of considerable importance. The primary etiologic factor in the pathogenesis of periodontal disease is the oral biofilm colonized by anaerobic bacteria. Among these, A. actinomycetemcomitans occupies an important place as a facultative anaerobic bacterium. In addition, A. actinomycetemcomitans possesses many virulence factors that contribute to its potential to cause cancer. This article provides an overview of the virulence factors of A. actinomycetecomitans and its association with various systemic diseases, its oncogenic potential, and the treatment options for infections caused by A. actinomycetecomitans.

Kombo knife combined with sorafenib in liver cancer treatment: Efficacy and safety under immune function influence

BACKGROUND

In the quest to manage hepatocellular carcinoma (HCC), the focus has shifted to a more holistic approach encompassing both data analytics and innovative treatments. Analyzing rich data resources, such as the cancer genome atlas (TCGA), and examining progressive therapies can potentially reshape the trajectory of HCC treatment.

AIM

To elucidate the immunological genes and the underlying mechanism of the combined Kombo knife and sorafenib regimen for HCC by analyzing data from TCGA and machine learning data.

METHODS

Immune attributes were evaluated via TCGA's postablation HCC RNA sequencing data. Using weighted gene coexpression network analysis and machine learning, we identified genes with high prognostic value. The therapeutic landscape and safety metrics of the integrated treatment were critically evaluated across cellular and animal models.

RESULTS

Immune genes-specifically, peptidylprolyl isomerase A and solute carrier family 29 member 3-emerged as significant prognostic markers. Enhanced therapeutic outcomes, such as prolonged progression-free survival and an elevated overall response rate, characterize the combined approach, with peripheral blood mononuclear cells displaying potent effects on HCC dynamics.

CONCLUSION

The combination of Kombo knife with sorafenib is an innovative HCC treatment modality anchored in immune-centric strategies.

Bidirectional Association between Periodontitis and Thyroid Disease: A Scoping Review

Periodontitis is a chronic inflammatory disease of the tissues surrounding and supporting the teeth. Due to the development of chronic inflammation, periodontitis can contribute to the development of several systemic diseases, including thyroid disease. Thyroid pathology includes benign, malignant, and autoimmune conditions leading to hypothyroidism, hyperthyroidism, or euthyroidism. Alterations in thyroid hormones, especially hypothyroidism, can reveal significant oral manifestations, including periodontitis. This scoping review aims to explore the probable causal relationship between periodontitis and thyroid disease, in terms of epidemiology, pathogenesis, and treatment. The search strategy follows the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, and Cochrane were searched from January 2014 to January 2024, entering the MESH terms "periodontitis" and "thyroid". Of 153 initial records, 20 articles were selected and discussed. There is a high prevalence of periodontitis among patients with thyroid disease, including thyroid cancer. The causes at the basis of this association are genetic factors, the oral microbiome, and proinflammatory cytokines. Periodontal treatment, specifically scaling and root planning, can ameliorate thyroid parameters. Although there are a few randomized controlled studies in the literature, this review lays the foundation for a bidirectional relationship between periodontitis and thyroid disease, the link to which is, once again, systemic inflammation.

Oral microbial dysbiosis in patients with oral cavity cancers

OBJECTIVES

The pathogenesis of oral cavity cancers is complex. We tested the hypothesis that oral microbiota dysbiosis is associated with oral cavity cancer.

MATERIALS AND METHODS

Patients with primary oral cavity cancer who met the inclusion and exclusion criteria were included in the study. Matching healthy individuals were recruited as controls. Data on socio-demographic and behavioral factors, self-reported periodontal measures and habits, and current dental status were collected using a structured questionnaire and periodontal chartings. In addition to self-reported oral health measures, each participant received a standard and detailed clinical examination. DNA was extracted from saliva samples from patients and healthy controls. Next-generation sequencing was performed by targeting V3-V4 gene regions of the 16 S rRNA with subsequent bioinformatic analyses.

RESULTS

Patients with oral cavity cancers had a lower quality of oral health than healthy controls. Proteobacteria, Aggregatibacter, Haemophilus, and Neisseria decreased, while Firmicutes, Bacteroidetes, Actinobacteria, Lactobacillus, Gemella, and Fusobacteria increased in oral cancer patients. At the species level, C. durum, L. umeaens, N. subflava, A. massiliensis, and V. dispar were significantly lower, while G. haemolysans was significantly increased (p < 0.05). Major periodontopathogens associated with periodontal disease (P. gingivalis and F.nucleatum) increased 6.5- and 2.8-fold, respectively.

CONCLUSION

These data suggested that patients with oral cancer had worse oral health conditions and a distinct oral microbiome composition that is affected by personal daily habits and may be associated with the pathogenicity of the disease and interspecies interactions.

CLINICAL RELEVANCE

This paper demonstrates the link between oral bacteria and oral cancers, identifying mechanistic interactions between species of oral microbiome.

Diversity and compositional differences in the oral microbiome of oral squamous cell carcinoma patients and healthy controls: a scoping review

Objectives

The human oral microbiome may play a role in the development of oral squamous cell carcinoma. The aim of this scoping review was to examine microbial diversity and differences in the composition of the oral microbiome between OSCC patients and healthy controls.

Methods

A literature search (in PubMed and Embase.com) was performed on January 9, 2023. The outcome variables used from the included studies of this review were alpha- and beta diversity and oral microbiome composition profiles for each taxonomic level (phylum-, class-, order-, genus- and species level).

Results

Thirteen out of 423 studies were included in this review compromising 1,677 subjects, of which 905 (54.0%) were OSCC patients and 772 (46.0%) were healthy controls. Most studies found a higher alpha diversity in the OSCC patient group and significantly different beta diversities between OSCC patient samples and healthy control samples. Studies reported more abundant Fusobacteria (on phylum level), Fusobacterium (on genus level), Fusobacterium nucleatum, Porphyromonas endodontalis and Prevotella intermedia (on species level) in OSCC patients. The healthy control group had more abundant Actinobacteria (on phylum level), Streptococcus and Veilonella (on genus level) and Veilonella parvula (on species level) according to most studies.

Conclusions

Our findings show differences in oral microbiome diversity and composition in OSCC patients. Clinical implications demand continuing study. Development of internationally accepted standard procedures for oral sample collection and oral microbiota analysis is needed for more conclusive and clinically relevant comparisons in future research.

Persistent infection with Porphyromonas gingivalis increases the tumorigenic potential of human immortalised oral epithelial cells through ZFP36 inhibition

The association between Porphyromonas gingivalis infection and oral squamous cell carcinoma (OSCC) has been established by numerous epidemiological studies. However, the underlying mechanism specific to this connection remains unclear. By bioinformatical analysis, we identified ZFP36 as a potentially significant co-expressed gene in both the OSCC gene database and the persistent infection model of P. gingivalis. To further investigate the role of ZFP36, we established a cell model that human immortalized oral epithelial cells (HIOECs) that were sustainedly infected by P. gingivalis (MOI = 1) for a duration of 30 weeks. Our findings indicated that sustained infection with P. gingivalis inhibited the expression of ZFP36 protein and induced changes in the biological behaviour of HIOECs. The mechanism investigation demonstrated the potential role of ZFP36 in regulating the cancer-related biological behaviour of HIOECs. Subsequent studies revealed that highly expressed CCAT1 could serve as a molecular scaffold in the formation of the ZFP36/CCAT1/MK2 complex. This complex formation enhanced the binding abundance of MK2 and ZFP36, thereby promoting the inhibition of ZFP36 protein phosphorylation. To summarize, low expression of ZFP36 protein under persistent P. gingivalis infection enhances the cancer-related biological behaviour of HIOECs.

Oral bacterial insights from a comparative study between healthy and comorbid diseased human individuals

The human oral cavity is colonized by a diverse microbial community, which includes both native and transient colonizers. The microbial composition is crucial for maintaining oral homeostasis, but due to overgrowth or imbalances of these microbial communities, dysbiosis can occur. There is a lack of understanding of the research of native and transient colonizers in the oral cavity of the Indian subpopulation Therefore, in our present study, we explored the role and prevalence of transient and native colonizers between healthy and comorbid oral diseased human individuals. Culture-dependent techniques and culture-independent 16S r DNA metagenomic analyses were employed to isolate and study the interactions of native and transient colonizers from human oral samples. Among the 66 human individuals of both healthy and comorbid individuals, the most abundant isolate was found to be Bacillus amyloliquefaciens MCC 4424. In addition, the more prevalent culturable isolate from the healthy samples was Streptococcus salivarius MTCC 13009, whereas in comorbid samples Staphylococcus pasteuri MTCC 13076, Rothia dentocariosa MTCC 13010 and Pseudomonas aeruginosa MTCC 13077 were prevalent to a greater extent. 16S rDNA metagenomic analyses revealed the prevalence and abundance of genera such as Bacteroidetes and Proteobacteria in healthy individuals; consequently, Fusobacteria and Firmicutes were observed mostly in comorbid individuals. The significant differences in bacterial population density were observed in terms of the Shannon index (p = 0.5145) and Simpson index (p = 0.9061) between the healthy and comorbid groups. B. amyloliquefaciens MCC 4424 exhibits antagonistic behavior when grown as a dual-species with native and transient colonizers. This result is very consistent with the findings of antibiofilm studies using confocal laser scanning microscopy, which revealed a significant reduction in biofilm biovolume (73 %) and maximum thickness (80 %) and an increase in the rough coefficient of biofilms (30 %). Our data suggested that B. amyloliquefaciens MCC 4424 can be a native colonizer of Indian sub-populations. It may act as a novel candidate for oral healthcare applications and greatly aids in the regulation of transient species in the oral cavity.

Immune and Microbial Signatures Associated with PD-1 Blockade Sensitivity in a Preclinical Model for HPV+ Oropharyngeal Cancer

The United States is suffering from an epidemic associated with high-risk strains of the Human Papillomavirus (HPV) predominantly responsible for the development of head and neck squamous cell carcinoma (HNSCC). Treatment with immune checkpoint inhibitors targeting programmed death 1 (PD-1) or its ligand PD-L1 has shown poor efficacy in HNSCC patients, observing only a 20-30% response. Therefore, biological marker identification associated with PD-1 blockade response is important to improve prognosis and define novel therapeutics for HNSCC patients. Therapy response was associated with increased frequencies of activated CD27+T cells, activated CD79a+ B cells, antigen-presenting CD74+ dendritic and B cells, and PD-L1+ and PD-L2+ myeloid-derived suppressor cells (MDSCs). The oral microbiota composition differed significantly in mice bearing tongue tumors and treated with anti-PD-1. A higher abundance of Allobaculum, Blautia, Faecalibacterium, Dorea, or Roseburia was associated with response to the therapy. However, an increase in Enterococcus was attributed to tongue tumor-bearing non-responding mice. Our findings indicate that differences in immune phenotypes, protein expression, and bacterial abundance occur as mice develop tongue tumors and are treated with anti-PD-1. These results may have a clinical impact as specific bacteria and immune phenotype could serve as biomarkers for treatment response in HNSCC.

Porphyromonas gingivalis, a bridge between oral health and immune evasion in gastric cancer

Porphyromonas gingivalis (P. gingivalis) is a gram-negative oral pathogen associated with chronic periodontitis. Previous studies have linked poor oral health and periodontitis with oral cancer. Severe cases of periodontal disease can result in advanced periodontitis, leading to tissue degradation, tooth loss, and may also correlate with higher gastric cancer (GC) risk. In fact, tooth loss is associated with an elevated risk of cancer. However, the clinical evidence for this association remains inconclusive. Periodontitis is also characterized by chronic inflammation and upregulation of members of the Programmed Death 1/PD1 Ligand 1 (PD1/PDL1) axis that leads to an immunosuppressive state. Given that chronic inflammation and immunosuppression are conditions that facilitate cancer progression and carcinogenesis, we hypothesize that oral P. gingivalis and/or its virulence factors serve as a mechanistic link between oral health and gastric carcinogenesis/GC progression. We also discuss the potential impact of P. gingivalis' virulence factors (gingipains, lipopolysaccharide (LPS), and fimbriae) on inflammation and the response to immune checkpoint inhibitors in GC which are part of the current standard of care for advanced stage patients.

About a Possible Impact of Endodontic Infections by Fusobacterium nucleatum or Porphyromonas gingivalis on Oral Carcinogenesis: A Literature Overview

Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis, two bacteria that cause periodontitis, are found in OSCC tissues as well as in oral premalignant lesions, where they exert pro-tumorigenic activities. Since the two bacteria are present also in endodontic diseases, playing a role in their pathogenesis, here we analyze the literature searching for information on the impact that endodontic infection by P. gingivalis or F. nucleatum could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by P. gingivalis and/or F. nucleatum triggers the production of inflammatory cytokines and growth factors in dental pulp cells or periodontal cells, affecting the survival, proliferation, invasion, and differentiation of OSCC cells. In addition, the two bacteria and the cytokines they induce halt the differentiation and stimulate the proliferation and invasion of stem cells populating the dental pulp or the periodontium. Although most of the literature confutes the possibility that bacteria-induced endodontic inflammatory diseases could impact on oral carcinogenesis, the papers we have analyzed and discussed herein recommend further investigations on this topic.

F. Nucleatum enhances oral squamous cell carcinoma proliferation via E-cadherin/β-Catenin pathway

BACKGROUND

Fusobacterium nucleatum (F. nucleatum) is a microbial risk factor whose presence increases the risk of oral squamous cell carcinoma (OSCC) progression. However, whether it can promote the proliferation of OSCC cells remains unknown.

METHODS

In this study, we investigated F. nucleatum effect on OSCC cell proliferation using in vitro and in vivo experiments.

RESULTS

Our results showed that F. nucleatum promoted OSCC cell proliferation, doubling the cell count after 72 h (CCK-8 assay). Cell cycle analysis revealed G2/M phase arrest. F. nucleatum interaction with CDH1 triggered phosphorylation, upregulating downstream protein β-catenin and activating cyclinD1 and Myc. Notably, F. nucleatum did not affect noncancerous cells, unrelated to CDH1 expression levels in CAL27 cells. Overexpression of phosphorylated CDH1 in 293T cells did not upregulate β-catenin and cycle-related genes. In vivo BALB/c nude experiments showed increased tumor volume and Ki-67 proliferation index after F. nucleatum intervention.

CONCLUSION

Our study suggests that F. nucleatum promotes OSCC cell proliferation through the CDH1/β-catenin pathway, advancing our understanding of its role in OSCC progression and highlighting its potential as a therapeutic target.