Shared epigenetic alterations between oral cancer and periodontitis: a preliminary study

Oral squamous cell carcinoma: Insights into cellular heterogeneity, drug resistance, and evolutionary trajectories

Oral squamous cell carcinoma (OSCC) can lead to metastasis and high mortality rates known for its aggressive and invasive properties. Currently, primary treatment options of surgical resection, chemotherapy and radiotherapy have many therapeutic limitations for OSCC patients due to its dynamic evolutionary pathways and the development of resistance to conventional therapies. Moreover, previous studies fail to emphasize the roles of cellular heterogeneity, drug resistance, and evolutionary trajectories in OSCC. This review explores the intricate tumor microenvironment landscape of OSCC, focusing on the cellular heterogeneity, drug resistance, and evolutionary trajectories as well as genetic, epigenetic, and environmental risk factors contributing to the OSCC progression. Tumor heterogeneity arises from environmental exposures (e.g., tobacco, HPV infection, dietary carcinogens) that drive clonal evolution, creating subpopulations of cells with distinct mutational profiles and therapeutic vulnerabilities. Recent advances in in the precision medicine and combination therapy of OSCC paves the way for innovative therapeutic strategies, such as targeting molecular subclones through real-time monitoring and leveraging computational models to predict treatment response. By recognizing tumor heterogeneity as both a driver of therapeutic resistance and a therapeutic target, precision medicine frameworks can integrate environmental risk factor data, molecular profiling, and early detection tools to optimize outcomes. This review underscores the necessity for a multidisciplinary approach to understand and combat the complexity of OSCC, proposing directions for future research to enhance diagnosis and treatment efficacy.

Evaluating the link between periodontitis and oral squamous cell carcinoma through Wnt/β-catenin pathway: a critical review

Oral Squamous Cell Carcinoma (OSCC), the main form of oral cancer, is a major health problem globally that affects 400,000 people every year. It has been postulated that periodontitis, a chronic inflammatory disease characterized by alveolar bone resorption, is an independent risk factor for OSCC. However, the mechanisms underlying this link are not fully elucidated. It has been demonstrated that the Wnt/β-catenin pathway is key to the transformation of oral potentially malignant disorders (OPMD) towards OSCC (i.e., leukoplakia), particularly in OPMD histologically diagnosed as oral dysplasia. Using a GEO database of oral carcinogenesis (GSE85195), the transcriptional modification of 19 Wnt ligands and 4 key regulatory proteins of β-catenin, including E-cadherin, APC, AXIN and GSK3B, during leukoplakia, and early and late stages OSCC, was determined. The transcriptional expression of these targets was also assessed in periodontitis (GEO database GSE223924). Together, it was found that Wnt ligands Wnt3, Wnt3a, Wnt5b and Wnt7b are concomitantly upregulated in periodontitis and oral carcinogenesis. With these results, and the information retrieved from the literature, this review discusses the potential role of the Wnt/β-catenin pathway as a molecular mechanism that could interlink periodontitis and OSCC.

Microbial community composition in subgingival plaques and heterogeneity of tumor tissue TCRβ CDR3 repertoire in patients with moderate-to-severe periodontitis and oral squamous cell carcinoma

BACKGROUND

The human oral cavity contains over 700 types of bacteria that may protect the body against colonization by exogenous pathogens and maintain relative homeostasis. However, alterations in the immune status can disrupt the balance between microorganisms and the host, inducing various diseases such as oral cancer and diabetes mellitus. The mechanism underlying this process is not clearly understood.

OBJECTIVE

The purpose of this study was to investigate the relationships between subgingival bacteria, T-cell receptor β-chain complementarity-determining region 3 (TCRβ CDR3), and the development oforal squamous cell carcinoma (OSCC).

METHODS

We grouped patients as "healthy periodontal" (H), "moderate-to-severe chronic periodontitis" (C), and "moderate-to-severe chronic periodontitis with OSCC" (T). Bacterial groups were "subgingival plaque" (bp) and "gingival/tumor tissue" (g). We also recorded patients' age, gender, attachment level (AL), bleeding on probing (BOP), and probing depth (PD). We extracted and sequenced RNA from plaques, gingival tissues, tumors, and teeth. We performed high-throughput sequencing on TCRβ CDR3 and plaque bacteria.

RESULTS

Synergistetes and Veillonella parvula were more abundant in the H group than in the T group. Granulicatella, Peptostreptococcus, and Streptococcus infantis were enriched in the T-bp group. AL, BOP, and PD were positively correlated with Granulicatella, Peptostreptococcus, and Pseudomonas but negatively correlated with Prevotella nigrescens and V. parvula. TCRβ CDR3 diversity was C > H > T. TCR β-chain Variable gene (TRBV)20-1 usage varied among the H, C, and T groups. TRBV2 and TRBV5-1 usage was greater in the T group than in the C group. TRBJ1-1, TRBJ1-2, TRBJ2-2, TRBJ2-7, and TRBJ2-5 were most frequently used.

CONCLUSIONS

These trends and the reduction of gingival Synergistetes were correlated with OSCC. TCRβ CDR3 diversity was the lowest in patients in the T group, and there were considerable changes in the expression of TRBV2 and TRBJ. Therefore, plaque bacterial composition can influence TCRβ CDR3.

Periodontitis and risk of cancer: Mechanistic evidence

This review aims to critically analyze the pathways of interaction and the pathogenic mechanisms linking periodontitis and oral bacteria with the initiation/progression of cancer at different body compartments. A higher risk of head and neck cancer has been consistently associated with periodontitis. This relationship has been explained by the local promotion of dysbiosis, chronic inflammation, immune evasion, and direct (epi)genetic damage to epithelial cells by periodontal pathobionts and their toxins. Epidemiological reports have also studied a possible link between periodontitis and the incidence of other malignancies at distant sites, such as lung, breast, prostate, and digestive tract cancers. Mechanistically, different pathways have been involved, including the induction of a chronic systemic inflammatory state and the spreading of oral pathobionts with carcinogenic potential. Indeed, periodontitis may promote low-grade systemic inflammation and phenotypic changes in the mononuclear cells, leading to the release of free radicals and cytokines, as well as extracellular matrix degradation, which are all mechanisms involved in carcinogenic and metastatic processes. Moreover, the transient hematogenous spill out or micro-aspiration/swallowing of periodontal bacteria and their virulence factors (i.e., lipopolysaccharides, fimbriae), may lead to non-indigenous bacterial colonization of multiple microenvironments. These events may in turn replenish the tumor-associated microbiome and thus influence the molecular hallmarks of cancer. Particularly, specific strains of oral pathobionts (e.g., Porphyromonas gingivalis and Fusobacterium nucleatum) may translocate through the hematogenous and enteral routes, being implicated in esophageal, gastric, pancreatic, and colorectal tumorigenesis through the modulation of the gastrointestinal antitumor immune system (i.e., tumor-infiltrating T cells) and the increased expression of pro-inflammatory/oncogenic genes. Ultimately, the potential influence of common risk factors, relevant comorbidities, and upstream drivers, such as gerovulnerability to multiple diseases, in explaining the relationship cannot be disregarded. The evidence analyzed here emphasizes the possible relevance of periodontitis in cancer initiation/progression and stimulates future research endeavors.

The Protective Role of Cranberries and Blueberries in Oral Cancer

BACKGROUND

Oral cancer has a high prevalence worldwide, and this disease is caused by genetic, immunological, and environmental factors. The main risk factors associated with oral cancer are smoking and alcohol.

RESULTS

There are various strategies to reduce risk factors, including prevention programs as well as the consumption of an adequate diet that includes phytochemical compounds derived from cranberries (Vaccinium macrocarpon A.) and blueberries (Vaccinium corymbosum L.); these compounds exhibit antitumor properties.

RESULTS

The main outcome of this review is as follows: the properties of phytochemicals derived from cranberries were evaluated for protection against risk factors associated with oral cancer.

CONCLUSIONS

The secondary metabolites of cranberries promote biological effects that provide protection against smoking and alcoholism. An alternative for the prevention of oral cancer can be the consumption of these cranberries and blueberries.