Oral squamous cell carcinoma: overview of current understanding of aetiopathogenesis and clinical implications

HOXA1 silencing inhibits cisplatin resistance of oral squamous cell carcinoma cells via IκB/NF-κB signaling pathway

The resistance of oral squamous cell carcinoma (OSCC) cells to cisplatin remains a tough nut to crack in OSCC therapy. Homeobox A1 (HOXA1) overexpression has been detected in head and neck squamous carcinoma (HNSC). Accordingly, this study aims to explore the potential role and mechanism of HOXA1 on cisplatin resistance in OSCC. The expression of HOXA1 in HNSC and its role in overall survival (OS) rate of OSCC patients were analyzed by bioinformatic analysis. Following transfection as needed, OSCC cells were induced by different concentrations of cisplatin, and the cell viability and apoptosis were evaluated by cell counting kit-8 and flow cytometry assays. The mRNA and protein expression levels of HOXA1 and the phosphorylation of IκBα and p65 were determined by real-time quantitative PCR and western blot. HOXA1 expression level was upregulated in HNSC tissues and OSCC cells. Overexpressed HOXA1 was correlated with a low OS rate of OSCC patients. Cisplatin exerted an anti-cancer effect on OSCC cells. HOXA1 silencing or cisplatin suppressed OSCC cell viability, boosted the apoptosis, and repressed the phosphorylation of IκBα and p65. Intriguingly, the combination of HOXA1 silencing and cisplatin generated a stronger anti-cancer effect on OSCC cells than their single use. HOXA1 silencing attenuates cisplatin resistance of OSCC cells via IκB/NF-κB signaling pathway, hinting that HOXA1 is a biomarker associated with OSCC and HOXA1 silencing can enhance the sensitivity of OSCC cells to cisplatin.

The potential value of oral microbial signatures for prediction of oral squamous cell carcinoma based on machine learning algorithms

OBJECTIVE

This study aimed to explore the potential predictive value of oral microbial signatures for oral squamous cell carcinoma (OSCC) risk based on machine learning algorithms.

METHODS

The oral microbiome signatures were assessed in the unstimulated saliva samples of 80 OSCC patients and 179 healthy individuals using 16S rRNA gene sequencing. Four different machine learning classifiers were used to develop prediction models.

RESULTS

Compared with control participants, OSCC patients had a higher microbial dysbiosis index (MDI, p < 0.001). Among four machine learning classifiers, random forest (RF) provided the best predictive performance, followed by the support vector machines, artificial neural networks and naive Bayes. After controlling the potential confounders using propensity score matching, the optimal RF model was further developed incorporating a minimal set of 20 bacteria genera, exhibiting better predictive performance than the MDI (AUC: 0.992 vs. 0.775, p < 0.001).

CONCLUSIONS

The novel MDI and RF model developed in this study based on oral microbiome signatures may serve as noninvasive tools for predicting OSCC risk.

SLC40A1 in iron metabolism, ferroptosis, and disease: A review

Solute carrier family 40 member 1 (SLC40A1) plays an essential role in transporting iron from intracellular to extracellular environments. When SLC40A1 expression is abnormal, cellular iron metabolism becomes dysregulated, resulting in an overload of intracellular iron, which induces cell ferroptosis. Numerous studies have confirmed that ferroptosis is closely associated with the development of many diseases. Here, we review recent findings on SLC40A1 in ferroptosis and its association with various diseases, intending to explore new directions for research on disease pathogenesis and new therapeutic targets for prevention and treatment. This article is categorized under: Cancer > Genetics/Genomics/Epigenetics Metabolic Diseases > Molecular and Cellular Physiology.

Dysbiosis linking periodontal disease and oral squamous cell carcinoma-A brief narrative review

An association between periodontal disease and oral squamous cell carcinoma (OSCC) has been recognized. However, there is no causal relationship between the two. The polymicrobial etiology of periodontal disease is confirmed, and so are the proven etiological factors for OSCC. Inflammation lies at the core of periodontal pathogenesis induced by the putative microbes. OSCC has inflammatory overtures in its pathobiology. Bacterial species involved in periodontal disease have been extensively documented and validated. The microbial profile in OSCC has been explored with no specific conclusions. The scientific reasoning to link a common microbial signature that connects periodontal disease to OSCC has led to many studies but has not provided conclusive evidence. Therefore, it would be beneficial to know the status of any plausible microbiota having a similarity in periodontal disease and OSCC. This brief review attempted to clarify the existence of a dysbiotic "fingerprint" that may link these two diseases. The review examined the literature with a focused objective of identifying periodontal microbial profiles in OSCC that could provide insights into pathogen commonality. The review concluded that there is great diversity in microbial association, but important bacterial species that correlate with periodontal disease and OSCC are forthcoming.

Obesity enhances the response to neoadjuvant anti-PD1 therapy in oral tongue squamous cell carcinoma

OBJECTIVES

Previous studies have demonstrated that obesity may impact the efficacy of anti-PD1 therapy, but the underlying mechanism remains unclear. In this study, our objective was to determine the prognostic value of obesity in patients with oral tongue squamous cell carcinoma (OTSCC) treated with pembrolizumab and establish a subtype based on fatty acid metabolism-related genes (FAMRGs) for immunotherapy.

MATERIALS AND METHODS

We enrolled a total of 56 patients with OTSCC who underwent neoadjuvant anti-PD1 therapy. Univariate and multivariate Cox regression analyses, Kaplan-Meier survival analysis, and immunohistochemistry staining were performed. Additionally, we acquired the gene expression profiles of pan-cancer samples and conducted GSEA and KEGG pathway analysis. Moreover, data from TCGA, MSigDB, UALCAN, GEPIA and TIMER were utilized to construct the FAMRGs subtype.

RESULTS

Our findings indicate that high Body Mass Index (BMI) was significantly associated with improved PFS (HR = 0.015; 95% CI, 0.001 to 0.477; p = 0.015), potentially attributed to increased infiltration of PD1 + T cells. A total of 91 differentially expressed FAMRGs were identified between the response and non-response groups in pan-cancer patients treated with immunotherapy. Of these, 6 hub FAMRGs (ACSL5, PLA2G2D, PROCA1, IL4I1, UBE2L6 and PSME1) were found to affect PD-1 expression and T cell infiltration in HNSCC, which may impact the efficacy of anti-PD1 therapy.

CONCLUSION

This study demonstrates that obesity serves as a robust prognostic predictor for patients with OTSCC undergoing neoadjuvant anti-PD1 therapy. Furthermore, the expression of 6 hub FAMRGs (ACSL5, PLA2G2D, PROCA1, IL4I1, UBE2L6 and PSME1) plays a pivotal role in the context of anti-PD1 therapy and deserves further investigation.

Identification of bio-active secondary metabolites from Actinobacteria as potential drug targets against Porphyromonas gingivalis in oral squamous cell carcinoma using molecular docking and dynamics study

Chronic periodontitis caused by the bacteria Porphyromonas gingivalis is thought to be a risk factor for the advancement of oral squamous cell carcinoma (OSCC). Virulence factors of P. gingivalis include gingipains, outer membrane surface lipoproteins, and fimbriae contribute to the activation of oncogenic pathways in OSCC by up-regulating different cytokines. Gingipains (Arg and Lys) proteases have an important role in the activation of proMMP-9, which promotes cellular invasion and metastatic ability of OSCC. Thus gingipains and MMP-9 were actively investigated as potential therapeutic targets in OSCC therapy. Various natural bioactive compounds from Actinobacteria have been explored for their anticancer potential in a variety of cancers, but very few studies have been reported in OSCC. Therefore, the current study is focused to identify potential actinobacterial compounds that can be considered as a therapeutic target against gingipains and inflammatory proteins in OSCC through high-throughput virtual screening, Molecular Docking (MD), and Molecular Dynamics Simulation (MDS) approaches. A total of 179 bioactive secondary metabolites of Actinobacteria were explored for their binding affinity against six virulence proteins of P. gingivalis. The Molecular Docking studies revealed that among 179 metabolites screened, Actinosporin G showed a highly acceptable binding affinity of -7.9 kcal/mol with RgpB (1CVR), and exhibited multi-protein targeting and drug-likeness property and passed level of toxicity. Comprehensive docking interaction of the best top-ranked Actinosporin G with OSCC-related protein targets illustrated high binding affinity towards MMP-9 and JAK-1 proteins among all targeted receptor proteins. The molecular dynamic (MD) simulation has been executed for the metabolite Actinosporin G for both bacterial gingipain (RgpB) and MMP-9 & JAK-1 showed stable intermolecular binding with both hydrogen and hydrophobic interactions. In conclusion, this work suggests that the bioactive secondary metabolite of Actinosporin G from Actinobacteria genera may serve as a promising therapy for P. gingivalis-induced OSCC.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00209-0.

Improved recurrence rates and progression-free survival in primarily surgically treated oral squamous cell carcinoma - results from a German tertiary medical center

OBJECTIVES

This study aimed to explore survival and recurrence patterns in patients undergoing primarily surgical treatment for oral squamous cell carcinoma (OSCC) at a high-volume tertiary medical center in Germany.

MATERIALS AND METHODS

The study included 421 patients with primary OSCC who underwent radical tumor resection, neck dissection, and reconstruction with a free flap. Prognostic relevance of clinicopathological characteristics was assessed using Cox proportional-hazards models. Kaplan-Meier method estimated local recurrence-free survival, progression-free survival (PFS), and overall survival (OS), while the log-rank test compared survival outcomes between groups.

RESULTS

Recurrence manifested in 16.63% of the patients (70 patients), encompassing local recurrence in 54 patients (77.14%) and distant metastasis in 24 patients (34.28%). Neck recurrence occurred in only 1 patient (0.24%) on the contralateral side. The majority of recurrences occurred within the initial twelve months following primary tumor surgery (64.29%). Overall, the 5-year OS stood at 58.29%, while the 5-year PFS reached 72.53%. Patients with early recurrence within ≤ 12 months showed the least favorable prognosis (log-rank, all p < 0.001).

CONCLUSIONS

Our findings show a significant decrease in recurrence rates and enhanced PFS at a high-volume tertiary medical center in Germany compared to previous studies. Local recurrence was the primary form observed, with most recurrences happening within the initial twelve months post-surgery. Opting for treatment at a high-volume center and devising therapy plans in interdisciplinary tumor boards may not only enhance OS but also contribute to improved PFS.

CLINICAL RELEVANCE

These findings offer valuable insights for physicians regarding the post-treatment care of patients with OSCC. The results underscore the importance of frequent follow-up appointments, particularly during the initial year, and highlight the critical need for vigilance in monitoring for local recurrence.

Expression of Toll-like receptors in oral squamous cell carcinoma

Almost 380,000 new cases of oral cancer were reported worldwide in 2020. Oral squamous cell carcinoma (OSCC) accounts for 90% of all types of oral cancers. Emerging studies have shown association of Toll-like receptors (TLRs) in carcinogenesis. The present study aimed to investigate the expression levels and tissue localization of TRL1 to TRL10 and NF-κB between OSCC and healthy oral mucosa, as well as effect of Candida colonization in TRL expression in OSCC. Full thickness biopsies and microbial samples from 30 newly diagnosed primary OSCC patients and 26 health controls were collected. The expression of TLR1 to TLR10 and NF-κB was analyzed by immunohistochemistry. Microbial samples were collected from oral mucosa to detect Candida. OSCC epithelium showed lower staining intensity of TRL1, TRL2 TRL5, and TRL8 as compared to healthy controls. Similarly, staining intensity of TRL3, TRL4, TRL7, and TRL8 were significantly decreased in basement membrane (BM) zone. Likewise, OSCC endothelium showed lower staining intensity of TLR4, TLR7 and TLR8. Expression of NF-κB was significantly stronger in normal healthy tissue compared to OSCC sample. Positive correlation was found between the expression of NF-κB, TRL9 and TRL10 in basal layer of the infiltrative zone OSCC samples (P = 0.04 and P = 0.002, respectively). Significant increase in TRL4 was seen in BM zone of sample colonized with Candida (P = 0.01). According to the limited number of samples, our data indicates downregulation of TLRs and NF-κB in OSCC, and upregulation of TLR4 expression with presence of Candida.

Disruption of CADM1-dependent cell-cell adhesion in human oral squamous cell carcinoma cells results in tumor progression, possibly through an increase of MMP-2 and MMP-9 expression

OBJECTIVES

This study aimed to clarify the molecular mechanism underlying the higher invasion and metastasis abilities of LMF4 cells than those of HSC-3 cells by comparing the expression levels of the tumor suppressor factor, cell adhesion molecule 1 (CADM1).

METHODS

We explored 1) whether CADM1 expression level was downregulated in LMF4 cells compared with HSC-3 cells, 2) whether CADM1 expression knockdown increased the expression levels of matrix metalloproteinases (MMPs), 3) the exact cellular signaling pathways responsible for increased MMP expression after knockdown of CADM1 expression, and 4) whether disruption of CADM1-dependent HSC-3 cell adhesion increased the migratory and invasive activities of HSC-3 cells.

RESULTS

CADM1 expression was lower in the LMF4 than in the HSC-3 cells. The knockdown of CADM1 increased the expression of MMP-2 and MMP-9 in HSC-3 cells. In addition, the upregulation of MMP-2 expression after CADM1 knockdown was abrogated by the mitogen-activated protein (MAP)/extracellular signal-regulated kinase kinase (MEK) inhibitor U0126 and the phosphoinositide 3-kinase (PI3K) inhibitor LY294002. The upregulation of MMP-9 expression after the knockdown of CADM1 was abrogated by the c-Jun N-terminal kinase (JNK) inhibitor SP600125 and the p38 MAP kinase (MAPK) inhibitor SB203580 and LY294002. Anti-CADM1 neutralizing antibody evoked migratory and invasive abilities of HSC-3 cells.

CONCLUSION

The disruption of CADM1-dependent cell-cell adhesion in human oral squamous cell carcinoma cells resulted in tumor progression, possibly through an increase in MMP-2 expression in a MEK/PI3K-dependent manner and an increase in MMP-9 expression in a JNK/p38 MAPK/PI3K-dependent manner.

Spatial Transcriptomic and Metabolomic Landscapes of Oral Submucous Fibrosis-Derived Oral Squamous Cell Carcinoma and its Tumor Microenvironment

In South and Southeast Asia, the habit of chewing betel nuts is prevalent, which leads to oral submucous fibrosis (OSF). OSF is a well-established precancerous lesion, and a portion of OSF cases eventually progress to oral squamous cell carcinoma (OSCC). However, the specific molecular mechanisms underlying the malignant transformation of OSCC from OSF are poorly understood. In this study, the leading-edge techniques of Spatial Transcriptomics (ST) and Spatial Metabolomics (SM) are integrated to obtain spatial location information of cancer cells, fibroblasts, and immune cells, as well as the transcriptomic and metabolomic landscapes in OSF-derived OSCC tissues. This work reveals for the first time that some OSF-derived OSCC cells undergo partial epithelial-mesenchymal transition (pEMT) within the in situ carcinoma (ISC) region, eventually acquiring fibroblast-like phenotypes and participating in collagen deposition. Complex interactions among epithelial cells, fibroblasts, and immune cells in the tumor microenvironment are demonstrated. Most importantly, significant metabolic reprogramming in OSF-derived OSCC, including abnormal polyamine metabolism, potentially playing a pivotal role in promoting tumorigenesis and immune evasion is discovered. The ST and SM data in this study shed new light on deciphering the mechanisms of OSF-derived OSCC. The work also offers invaluable clues for the prevention and treatment of OSCC.

Downregulation of SLC3A2 mediates immune evasion and accelerates metastasis in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignancy originating from oral mucosal tissue. OSCC cells employ immune evasion strategies to avoid immune attacks, but research on inhibiting immune evasion and delaying OSCC progression is limited. This study aimed to investigate how SLC3A2 downregulation mediates immune evasion and promotes metastasis in OSCC through bioinformatics analysis and cell experiments. Gene enrichment analysis was performed using human double sulphur death-related genes from the GSEA database. Differentially expressed genes were selected from the GEO database. Diagnostic models were constructed and validated using gene expression datasets. Immune infiltration and function were analysed through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Cell experiments were conducted to evaluate the impact of SLC3A2 on immune response in OSCC. Ten double sulphur death-related genes were identified, with SLC3A2 and SLC7A11 being enriched in tongue squamous cell carcinoma-related diseases. Differential expression analysis revealed five genes (SLC3A2, SLC7A11, RPN1, GYS1 and NDUFS1) of diagnostic significance. GO analysis showed enrichment in amino acid import and transmembrane transport, while KEGG pathway analysis highlighted enrichment in ferroptosis, diabetic cardiomyopathy, and Starch and sucrose metabolism. Experimental verification confirmed higher SLC3A2 expression in OSCC cells. Overexpression of SLC3A2 inhibited cell proliferation and reduced PD-1 and CTLA-4 expression. Reduced SLC3A2 expression in OSCC promotes immune evasion and tumour progression by impairing T lymphocyte function. This study provides insights into targeted regulation of SLC3A2 expression for immune response-based therapies in OSCC.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Exploring the Potential of Bee-Derived Antioxidants for Maintaining Oral Hygiene and Dental Health: A Comprehensive Review

Honey bee products comprise various compounds, including honey, propolis, royal jelly, bee pollen, bee wax and bee venom, which have long been recognized for their pharmacological and health-promoting benefits. Scientists have discovered that periodontal disorders stem from dental biofilm, an inflammatory response to bacterial overgrowth produced by dysbiosis in the oral microbiome. The bee products have been investigated for their role in prevention of oral diseases, which are attributed to a myriad of biologically active compounds including flavonoids (pinocembrin, catechin, caffeic acid phenethyl ester (CAPE) and galangin), phenolic acids (hydroxybenzoic acid, hydroxycinnamic acid, p-coumaric, ellagic, caffeic and ferulic acids) and terpenoids. This review aims to update the current understanding of role of selected bee products, namely, honey, propolis and royal jelly, in preventing oral diseases as well as their potential biological activities and mechanism of action in relation to oral health have been discussed. Furthermore, the safety of incorporation of bee products is also critically discussed. To summarize, bee products could potentially serve as a therapy option for people suffering from a variety of oral disorders.

Localization and characterization of human papillomavirus-16 in oral squamous cell carcinoma

OBJECTIVES

The role of Human papillomavirus (HPV) in the oral squamous cell carcinoma (OSCC) has not been completely elucidated. The purpose of the present study was to investigate the prevalence and localization of HPV-16 virus in OSCC and to correlate HPV-16 positivity and p16INK4A expression with the clinical and pathological features of OSCC.

METHODS

The archives of Oral Pathology at the University of Florida, College of Dentistry were accessed for demographic, clinical, histopathological data, and slides of 114 OSCC patients. HPV-16 positivity of OSCC was evaluated by p16INK4A immunohistochemistry (IHC) and HPV-16 E6/E7mRNA by in situ hybridization (ISH).

RESULTS

Out of 114 consecutive pathological slides of OSCC, 16 samples (14%) showed positivity for p16INK4A by IHC and 14 samples (12%) were positive for HPV-16 E6/E7mRNA ISH and the Positivity showed a significant correlation with the patients' age, alcohol consumption, and the degree of OSSC differentiation. The hard palate showed the highest positivity of p16INK4A IHC and HPV-16 mRNA ISH (38%, 36% respectively).

CONCLUSION

HPV-16 is a significant factor in oral carcinogenesis. We recommend using p16INK4A as a surrogate marker for HPV detection in OSCC, which can be complemented by RNA ISH for the identification of HPV subtypes.

Oral dysbiosis in the onset and carcinogenesis of oral epithelial dysplasia: A systematic review

OBJECTIVE

This systematic review aims to investigate possible connections between the oral microbiome and the onset and carcinogenesis of oral epithelial dysplasia (OED).

METHODS

A systematic search was performed on PubMed, Embase, Cochrane Database, and SCOPUS by two authors independently, addressing the focused question- "Has oral microbiome dysbiosis been involved in the onset and carcinogenesis of oral epithelial dysplasia?" We used the Newcastle-Ottawa scale to assess the quality of studies included in the review.

RESULTS

Out of 580 references screened, ten studies were found eligible for inclusion. All studies were case-control studies, and only qualitative analysis was conducted due to heterogeneous characteristics. The overall risk of bias in the eligible studies was considered as high. Microbiome diversity indices showed inconsistent evidence among studies. A significant increase of phylum Bacteroidetes in OED patients was reported in five studies. Five studies reported an increase of genus Fusobacterium in both the OED and oral squamous cell carcinoma (OSCC) patients and six different studies respectively reported a reduction of genus Streptococcus in both the OED and OSCC groups when compared to normal controls. Other predominant bacteria that were specific to different patient groups varied in each study.

CONCLUSIONS

The results of the included studies showed that the composition of the oral microbiome in patients with OED compared to healthy controls and OSCC patients was inconsistent. However, all ten studies showed non-negligible heterogeneity in the type and size of the sample, and the comparability between groups, which strongly limited the external validity of results. Further studies are strongly recommended.

[Survival of young adults with oral squamous cell carcinoma in a brazilian population]

OBJECTIVE

To analyze the profile and survival in young adults with oral squamous cell carcinoma, attended at the High Complexity in Oncology of Feira de Santana, Brazil, between 2010 and 2016.

METHODS

Retrospective cohort, performed through the information of the medical records of all young patients attended in the referred center. Descriptive analysis of the variables, Fisher's exact test, Kaplan-Meier curve and log-rank test were performed.

RESULTS

A total of 35 patients were registered. The majority were male, smokers and former alcoholics. Tumors were predominantly localized in the tongue, diagnosed at late stages, classified as well differentiated and treated mainly with surgery associated to radiotherapy and chemotherapy. The median survival time was 31 months and 22.8% of the patients died. The variables that presented statistical significance in relation to the survival time were the tumor site and the type of treatment.

CONCLUSION

The profile and low survival time reflect the need for greater attention to the disease in this population.

Evaluation of Immunoexpression of AJUBA Protein in Normal Oral Mucosa and Oral Squamous Cell Carcinoma

AJUBA is multifunctional scaffold protein which belongs to Zyxin family of proteins. It is known to have dual role in cancer as a tumor promoter and tumor suppressor. AJUBA has a key role in systemic malignancies like esophageal squamous cell carcinoma, colorectal cancer, cervical, breast, prostate cancer, etc. But there is very sparse literature available regarding its expression profile in oral squamous cell carcinoma (OSCC) and moreover its expression has not been observed in normal oral mucosa (NOM). Thus, the aim of this research is to explore the expression profile of AJUBA by immunohistochemical method in NOM and OSCC. Furthermore, we also evaluated the association of AJUBA expression with clinicopathologic parameters. A total of 84 samples of formalin fixed paraffin embedded tissue blocks comprising of 42 cases each of NOM and OSCC were subjected to detect immunoexpression of AJUBA. We found enhanced intense immune-expression of AJUBA in OSCC cases than compared with NOM and found to be statistically significant. The parameters specific to histologic tumor grade and inflammatory response in OSCC also found to have statistically significant with AJUBA expression. Our study is first of its kind to reveal AJUBA expression in basal and suprabasal layer of NOM suggestive of its definitive role in differentiation and stratification process. We also observed its intense expression in peripheral cell of tumor islands of OSCC cases, which can suggest its possible role in tumor growth and progression.

Influence of site and smoking on malignant transformation in the oral cavity: Is the microbiome the missing link?

The tongue and floor of the mouth are high-risk sites for oral squamous cell carcinoma (OSCC), while smoking is its most significant risk factor. Recently, questions have been raised as to the role of the oral microbiome in OSCC because of a wealth of evidence demonstrating that the microbiome of OSCC differs from that of healthy mucosa. However, oral site and smoking also have a significant impact on oral microbial communities, and to date, the role these factors play in influencing the dysbiotic microbial communities of OSCC and precursor lesions has not been considered. This review aims to examine the influence of site and smoking on the oral microbiome and, in turn, whether these microbiome changes could be involved in oral carcinogenesis.

Association between sociodemographic characteristics and level of knowledge about oral cancer among Mexican dental health professionals: a cross-sectional online survey

BACKGROUND

A good level of knowledge in dentists is crucial for an early diagnosis of oral cancer (OC). In Latin America there are a few studies of OC knowledge among dentist, those has been performed in Brazil, Colombia, and Chile, and their results showed low level of OC knowledge. On the other hand, there is no publication in which the level of knowledge of dentists in Mexico has been addressed. Therefore, this study aimed to assess knowledge of OC and to determine the association of the level of knowledge with sociodemographic characteristics among dentists in Mexico.

METHODS

A cross-sectional online survey was designed to obtain information via questionnaire. The questionnaire was developed in the Spanish language, and the content validity was determined. The study was conducted among Mexican dentists with a 23-item questionnaire that was designed to be anonymous. The sample size was calculated using the finite population formula. Based on the responses, the level of knowledge of OC was categorized as very low, low, regular, good, or excellent. Additionally, the association between sociodemographic characteristics and the level of knowledge about OC was evaluated.

RESULTS

This research was conducted on a sample of 387 dentists. Most of the respondents were general dentists and worked in urban zones. The majority of dentists lacked a specialty (76.7%). Additionally, most of the respondents were students (44.2%). The level of knowledge of the participants was between regular and good (77.8%). On the other hand, concerning self-evaluation, most of the participants considered their knowledge of OC to be regular (50.6%). In addition, there was no association between sociodemographic characteristics and knowledge about OC.

CONCLUSIONS

This research identified some weaknesses in most Mexican dentists' knowledge of OC.

Oral Squamous Cell Carcinomas Developing from Oral Lichen Planus: A 5-21 year Retrospective Study

Background and Aims

There is insufficient data regarding clinical characteristics, relapse rates, as well as lymph node metastasis of squamous cell carcinomas of the oral cavity (OSCC) developing from oral lichen planus (OLP-OSCC). The aim of this retrospective study was to evaluate clinical characteristics, as well as relapse, recurrence and survival rates of OLP-OSCC.

Methods

In a retrospective monocenter analysis, all consecutive patients with an OSCC treated in the time period 1st January 2000-December 31 2016 were reviewed. All patients with OSCC developing from OLP/OLL (oral lichenoid lesions) were identified and analyzed for epidemiological data, risk profile, location of primary tumor, pTNM classification, lymph node metastasis, primary therapy, recurrence, and outcome.

Results

A total of 103 patients (45%♂/ 55%♀) with an average age of 62 ± 14 year were included in this study. At the time of initial diagnosis, 17% (n = 18) of patients had cervical metastases (CM) whereas only 11% (11 patients) displayed advanced tumor sizes (T > 2). T-status (p = 0.003) and histopathological grading (p = 0.001) had an impact on the incidence of CM. 39.6% of the patients developed a relapse after an average of 24 months with a mean of two recurrences per patient. Advanced tumor size had a significant impact on the 5 year overall survival and was associated with disease-free survival of the patients (p < 0.001, respectively p = 0.004).

Conclusion

Although initial lymph node metastases were not more frequent, more aggressive recurrence patterns compared to OSCC were seen for OLP-OSCC. Therefore, based on the study results, a modified recall for these patients is suggested.

Oral Squamous Cell Carcinoma Frequency in Young Patients from Referral Centers Around the World

Oral squamous cell carcinoma (OSCC) commonly affects older patients; however, several studies have documented an increase in its incidence among younger patients. Therefore, it is important to investigate if this trend is also found in different geographic regions. The pathology files of diagnostic and therapeutic institutions from different parts of the globe were searched for OSCC cases diagnosed from 1998 to 2018. Data regarding the sex, age, and tumor location of all cases, as well as the histologic grade and history of exposure to risk habits of cases diagnosed as OSCC in young patients (≤ 40 years of age) were obtained. The Chi-square test was used to determine any increasing trend. A total of 10,727 OSCC cases were identified, of which 626 cases affected young patients (5.8%). Manipal institution (India) showed the highest number of young patients (13.2%). Males were the most affected in both age groups, with the tongue and floor of the mouth being the most affected subsites. OSCC in young individuals were usually graded as well or moderately differentiated. Only 0.9% of the cases occurred in young patients without a reported risk habit. There was no increasing trend in the institutions and the period investigated (p > 0.05), but a decreasing trend was observed in Hong Kong and the sample as a whole (p < 0.001). In conclusion there was no increase of OSCC in young patients in the institutions investigated and young white females not exposed to any known risk factor represented a rare group of patients affected by OSCC.

UCHL1 promotes proliferation and metastasis in head and neck squamous cell carcinoma and could be a potential therapeutic target

OBJECTIVE

The purpose of this study was to research the physiological roles of ubiquitin carboxyl-terminal esterase L1 (UCHL1) in head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Ten HNSCC samples and matched normal oral mucosal tissues were collected. UCHL1 expression of these tissues was detected by the immunohistochemical staining and real-time quantitative polymerase chain reaction. The human HNSCC cell line HN6 UCHL1 knockout (UCHL1 KO) cell line was constructed using CRISPR/CAS9 gene editing and verified by western blotting. Wound healing assay, cell proliferation assay, cell invasion assay, and flow cytometric analysis of the cell cycle and apoptosis were applied to research the role of UCHL1 in HNSCC. Also, an RNAseq gene expression data set and HNSCC patient survival data from The Cancer Genome Atlas were analyzed.

RESULTS

UCHL1 was highly expressed in HNSCC tissues compared with normal oral mucosal tissues (P = .032). A decreased proliferation (P < .0001), migration (P < .0001), and invasion (P = .0049) ability of HN6 cells was exhibited after knockout of UCHL1. However, HN6 UCHL1 KO cells showed no significant differences in the cell cycle or apoptosis. The progression, nodal metastasis status, and stage of HNSCC had a positive correlation with the expression of UCHL1.

CONCLUSIONS

UCHL1 plays an important role in HNSCC, and we consider that targeting UCHL1 may be a feasible therapeutic strategy for HNSCC.

Comparison of five-year survival rates among patients with oral squamous cell carcinoma with and without association with syphilis: a retrospective case-control study

BACKGROUND

Syphilis is an infectious disease that is at least discussed to be premalignant. This potential, combined with its general pathological impact, raises the question if syphilis increases mortality in oral cancer patients. The aim of the study was to assess if the five-year survival rates among patients suffering from oral squamous cell carcinoma (OSCC) with (cohort I) and without association with syphilis (cohort II) differ.

METHODS

Retrospective clinical data of patients diagnosed with OSCC (International Classification of Diseases [ICD]-10 codes C01-06) within the past 20 years from the access date September 25, 2021 were retrieved from the TriNetX network (TriNetX, Cambridge, Massachusetts, USA) to gain initial cohort 0. Subjects also diagnosed with syphilis (ICD-10 codes A51-53) were assigned to cohort I. Cohort II was comprised of the remaining individuals of cohort 0 by creating a group with the same number of patients as cohort I, and by matching for age and gender. Subsequently, Kaplan-Meier analysis and Cox proportional hazards regression were performed, and risk, odds and hazard ratios were calculated.

RESULTS

Of a total of 73,736 patients in cohort 0, 199 individuals were each assigned to cohort I and II. During the five-year period after tumor diagnosis, 39 and 30 patients in cohort I and II died. The five-year survival probabilities did not significantly differ between the cohorts (I vs. II = 74.19% vs. 75.01%; p = 0.52; Log-Rank test), nor the risk of dying (I vs. II = 19.6% vs. 15.08%; risk difference = 4.52%; p = 0.23). The calculated risk, odds and hazard ratios were 1.3 (95% confidence interval [CI] = 0.84; 2.00), 1.37 (95% CI = 0.81; 2.31) and 1.17 (95% CI = 0.73; 1.88), respectively.

CONCLUSIONS

The obtained results indicate that the survival rate of individuals with OSCC might not be negatively influenced if syphilis is present/associated. However, the results need to be interpreted cautiously due to limitations related to the retrospective approach, especially as data on the tumor staging were not accessible.

TRIAL REGISTRATION

Due to the retrospective nature of the study, no registration was necessary.

Applications of Plasma-Activated Water in Dentistry: A Review

The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes. This interest has extended to dentistry, since the use of a plasma–liquid technology could bring clinical advantages, compared to direct application of non-thermal atmospheric pressure plasmas (NTAPPs). The aim of this paper is to discuss the applicability of PAW in different areas of dentistry, according to the published literature about NTAPPs and plasma–liquid technology. The direct and indirect application of NTAPPs are presented in the introduction. Posteriorly, the main reactors for generating PAW and its active constituents with a role in biomedical applications are specified, followed by a section that discusses, in detail, the use of PAW as a tool for different oral diseases.

Expression profile of the PI3K-AKT-mTOR pathway in head and neck squamous cell carcinoma: Data from Brazilian population

OBJECTIVE

The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of the rapamycin (PI3K-AKT-mTOR) signaling pathway is an important regulator of cell proliferation, survival, and motility. The gain or loss of function of proteins related to this pathway results in the neoplastic transformation in several types of cancers. This study aimed to evaluate the expression profile of the PI3K-AKT-mTOR pathway in patients with head and neck squamous cell carcinoma (HNSCC) and HNSCC cell lines.

STUDY DESIGN

The study involved 26 formalin-fixed paraffin-embedded tissue samples from patients with HNSCC. The analysis of immunohistochemical expression of PI3K, AKT, p-mTOR, and phosphatase and tensin homolog (PTEN) proteins was performed by a quantitative assessment. The in vitro gene and protein expression evaluation was performed by real-time polymerase chain reaction and Western blot assay, respectively, in the human cell lines SCC-9 and FaDu.

RESULTS

High levels of PI3K, AKT, and p-mTOR were found in most HNSCC tumors. Following this result, we observed low amounts or absence of PTEN in most samples. Additionally, the FaDu cells (pharynx) showed higher AKT expression but lower expression of p-mTOR compared with SCC-9 cells (oral cavity), which hints at a loco-anatomical relevance.

CONCLUSION

Overall, this study found increased expression of the PI3K-AKT-mTOR pathway along with evident PTEN reduction in head and neck cancer.

Mesenchymal Stromal/Stem Cells-Derived Exosomes as an Antimicrobial Weapon for Orodental Infections

The oral cavity as the second most various microbial community in the body contains a broad spectrum of microorganisms which are known as the oral microbiome. The oral microbiome includes different types of microbes such as bacteria, fungi, viruses, and protozoa. Numerous factors can affect the equilibrium of the oral microbiome community which can eventually lead to orodental infectious diseases. Periodontitis, dental caries, oral leukoplakia, oral squamous cell carcinoma are some multifactorial infectious diseases in the oral cavity. In defending against infection, the immune system has an essential role. Depending on the speed and specificity of the reaction, immunity is divided into two different types which are named the innate and the adaptive responses but also there is much interaction between them. In these responses, different types of immune cells are present and recent evidence demonstrates that these cell types both within the innate and adaptive immune systems are capable of secreting some extracellular vesicles named exosomes which are involved in the response to infection. Exosomes are 30-150 nm lipid bilayer vesicles that consist of variant molecules, including proteins, lipids, and genetic materials and they have been associated with cell-to-cell communications. However, some kinds of exosomes can be effective on the pathogenicity of various microorganisms and promoting infections, and some other ones have antimicrobial and anti-infective functions in microbial diseases. These discrepancies in performance are due to the origin of the exosome. Exosomes can modulate the innate and specific immune responses of host cells by participating in antigen presentation for activation of immune cells and stimulating the release of inflammatory factors and the expression of immune molecules. Also, mesenchymal stromal/stem cells (MSCs)-derived exosomes participate in immunomodulation by different mechanisms. Ease of expansion and immunotherapeutic capabilities of MSCs, develop their applications in hundreds of clinical trials. Recently, it has been shown that cell-free therapies, like exosome therapies, by having more advantages than previous treatment methods are emerging as a promising strategy for the treatment of several diseases, in particular inflammatory conditions. In orodental infectious disease, exosomes can also play an important role by modulating immunoinflammatory responses. Therefore, MSCs-derived exosomes may have potential therapeutic effects to be a choice for controlling and treatment of orodental infectious diseases.

Digital biomarker 2D:4D as a predictor of cancer: A systematic review

BACKGROUND

The digital ratio between the second and fourth digits of the hands, known as 2D:4D, is sexually dimorphic. It has been suggested that a low 2D:4D indicates high exposure to prenatal testosterone and low estrogen exposure while a high 2D:4D indicates the inverse. The 2D:4D may be predictive of cancer susceptibility, and this may be particularly true in cancers that show differences between sexes in their occurrence.

AIM

To conduct a systematic review of published epidemiological literature examining the association between 2D:4D and cancer.

METHOD

This review was carried out according to criteria recommended for the systematic review of Statement PRISMA. We enrolled 25 papers involving eleven cancer topographies with 4,569 cases and 19,416 controls from Europe, America, Asia and Australia.

RESULTS

We noticed variations and discrepancies in the results of the association between 2D:4D and cancer among the studies, either in those that had evaluated the same or different types of cancer, or in the same or distinct lateralities. However, a high 2D:4D was considered a likely predictor of cancer risk in 11 of 25 studies, a low 2D:4D was suggested as a predictor of risk in eight papers, and five of the twenty-five studies did not demonstrate any association.

CONCLUSIONS

Although this biomarker has the advantage of being easy to measure, it is noted that its relationship with sex hormone levels at specific stages of life has not yet been well quantified, and it has still been questioned. Hence, it is suggested that those findings from studies involving 2D:4D as a proxy for foetal hormone exposure should be interpreted with caution, as well as those studies which claim its association with cancer. Thus, this review shows the need for a greater number of epidemiological studies using more homogeneous methodology and techniques to better investigate the strength of the findings.

Re-Emphasizing the Roles of General Medical and Dental Practitioners Regarding Oral Cancer Eradication in Nigeria

The burden of oral cancer in Nigeria is largely under-reported. The available data on oral cancer etiology/risk factors, clinical features, disease burden, and literacy rate in Nigeria points towards a possible explosion in prevalence in the near future, which poses a serious public health concern. The general medical and dental practitioners (GMDPs) in Nigeria can salvage this looming problem through appropriate public health and clinical interventions. This narrative review article re-emphasizes the key roles of GMDPs towards oral cancer eradication in Nigeria. It also discusses oral cancer case definition, etiology, risk factors, and the epidemiological burden in the Nigerian context.

The expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma

P-cadherin (CDH3) is a cell-to-cell adhesion molecule that regulates several cellular homeostatic processes in normal tissues. Lack of CDH3 expression is associated with aggressive behavior in oral squamous cell carcinoma (OSCC). Previous studies have shown that CDH3 is downregulated in high-grade OSCC and its reduced expression is predictive for poorer survival. The aim of this study was to evaluate the expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma (TSCC). A retrospective series of 211 TSCC and 50 lymph node samples were stained immunohistochemically with polyclonal antibody (anti-CDH3). CDH3 expression was assessed semi-quantitatively with light microscopy. Fisher's exact test was used to compare patient and tumor characteristics, and the correlations were tested by Spearman correlation. Survival curves were drawn by the Kaplan-Meier method and analyzed by the log-rank test. Univariate and multivariate Cox regression was used to estimate the association between CDH3 expression and survival. CDH3 expression did not affect TSCC patient's disease-specific survival or overall survival. Strong CDH3 expression in the primary tumor predicted poor disease-specific and overall survival in patients with recurrent disease. CDH3 expression in lymph nodes without metastasis was negative in all cases. CDH3 expression was positive in all lymph node metastases with extranodal extension. In contrast to previous report about the prognostic value of CDH3 in OSCC, we were not able to validate the result in TSCC.

Oral cancer awareness in patients attending university dental clinics: A scoping review of Australian studies

This scoping review was carried out to evaluate the important role Australian university-based dental teaching clinics and dental students might have in promoting oral cancer awareness in their patients. Four Online database (PubMed, OVID, Scopus and Emcare) were searched for studies that assessed oral cancer awareness amongst patients attending Australian university-associated (teaching) clinics. A total of five articles were retrieved for full-text analysis. All studies showed significant variation in patient awareness and understanding regarding the principal risk factors associated with oral cancer development. Smoking was predominantly identified as a significant risk factor, but alcohol consumption was less frequently recognized as relevant. Non-healing ulceration was most commonly identified as a symptom of concern, whilst red and/or white mucosal patches were infrequently recognized as potentially malignant conditions. Our review confirms that a significant lack of patient awareness regarding oral cancer risk and the signs /symptoms of early malignancy or potentially malignant disease exist in patients attending dental teaching clinics. Important opportunities exist to involve dental students proactively in raising oral cancer awareness, delivering smoking cessation interventions and safe alcohol consumption advice to their patients. Incorporation of established health educational models might deliver effective support for such student-delivered patient education.

PRPF19 promotes tongue cancer growth and chemoradiotherapy resistance

Pre-mRNA processing factor 19 (PRPF19) is a multifaceted protein and participates in DNA damage response and pre-mRNA processing. The role of PRPF19 in cancer is unclear. Here, we report that the expression of PRPF19 in human tongue cancer is associated with unfavorable prognosis. Overexpression of PRPF19 promotes while knockdown of PRPF19 inhibits tongue cancer cell migration, proliferation, and tumor growth. Overexpression of PRPF19 increases the resistance of tongue cancer cells to radiation and cisplatin treatment. Furthermore, PRPF19 regulates the expression of solute carrier family 40 member 1 (SLC40A1) and mono-ADP ribosylhydrolase 2 (MACROD2), knockdown of SLC40A1 or MACROD2 decreases the sensitivity of tongue cancer cells to radiation and cisplatin treatment. Thus, our results establish a key role of PRPF19 in tongue cancer growth and chemoradiotherapy resistance, targeting PRPF19 would be an effective therapeutic strategy for tongue cancer, especially for those resistant to chemoradiotherapy.

Focus on HPV Infection and the Molecular Mechanisms of Oral Carcinogenesis

This study is focused on the epidemiological characteristics and biomolecular mechanisms that lead to the development of precancerous and cancerous conditions of oral lesions related to Human Papilloma Virus (HPV) infections. Current evidence from the literature demonstrates the role of HPV in potentially malignant oral disorders. Therefore, the underlying biomolecular processes can give arise, or contribute to, benign lesions as well as to oral carcinogenesis.

Oral Cancer and Precancer: A Narrative Review on the Relevance of Early Diagnosis

Oral cancer (OC) is an uncommon malignancy in Western countries, being one of the most common cancers in some high-risk areas of the world. It is a largely preventable cancer, since most of the different risk factors identified, such as tobacco use, alcohol consumption, and betel nut chewing, are behaviors that increase the likelihood of the disease. Given its high mortality, early diagnosis is of utmost importance. Prevention and the anticipation of diagnosis begin with identification of potentially malignant lesions of the oral mucosa and with local conditions promoting chronic inflammation. Therefore, every lesion must be recognized promptly and treated adequately. The clinical recognition and evaluation of oral mucosal lesions can detect up to 99% of oral cancers/premalignancies. As stated by the World Health Organization, any suspicious lesion that does not subside within two weeks from detection and removal of local causes of irritation must be biopsied. Surgical biopsy remains the gold standard for diagnosis of oral cancer. Adjunctive tools have been developed and studied to help clinicians in the diagnostic pathway, such as toluidine blue vital staining and autofluorescence imaging. In the near future other methods, i.e., identification of salivary markers of progression may help in reducing mortality due to oral cancer.

Death by histone deacetylase inhibitor quisinostat in tongue squamous cell carcinoma via apoptosis, pyroptosis, and ferroptosis

Tongue cancer is one of the most common oral malignancies. Quisinostat is a histone deacetylase inhibitor with antitumor activity. The aim of this study was to evaluate the effects of quisinostat on the viability of tongue squamous cell carcinoma (TSCC) cells (CAL-27, TCA-8113) in vitro and in vivo. Cell viability, cell morphological observation, scratch wound-healing assay, transwell migration assay, transmission electron microscope, flow cytometry and cellular reactive oxygen species were assessed in vitro. The results showed that quisinostat can significantly inhibit the viability, growth and migration of TSCC cells. And quisinostat could significantly induce TSCC cells apoptosis, pyroptosis, and ferroptosis. Quisinostat significantly inhibited tumor tissue growth in animal experiments. Up-regulation of the expression of Bax, cleaved-caspase3, caspase-1, p53, phospho-p53 and down-regulated of the expression of caspase-3, Bcl-2, GPX4 in cell lines and tumor tissues of nude mice were observed by Western blotting analysis. Up-regulation of the expression of caspase-1, Bax, cleaved-caspase3, p53 and down-regulated of the expression of ki67, caspase-3, Bcl-2, GPX4 in tumor tissues of nude mice were observed by immunohistochemistry. TUNEL analysis showed that quisinostat could increase the apoptosis rate in the tumor tissues of nude mice. Up-regulation of the expression of p53 and down-regulated expression of GPX4 in cell lines were observed by immunofluorescent staining, and the expression locations of p53 and GPX4 proteins in TSCC cells were observed. Based on these findings, quisinostat may be a potential drug for the treatment of tongue squamous cell carcinoma.

High expression of novel biomarker KRT16P3 promotes the progression of tongue squamous cell carcinoma and predicts poor prognosis

BACKGROUND

Overexpression of long non-coding RNAs (lncRNAs) reveals the abnormal pathological processes in many human cancers. KRT16P3, a novel overexpressed lncRNA in tongue squamous cell carcinoma (TSCC), was identified by previous lncRNA microarrays. However, the role of KRT16P3 in TSCC is not clear.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of KRT16P3 in TSCC tissues and cells. Next, the relationships between KRT16P3 and the clinical significance of TSCC patients were analyzed. Additionally, Cell Counting Kit-8, 5-Bromo-2-deoxyuridine (BrdU) incorporation assay, cell colony formation assay, flow cytometry cell apoptosis analysis, scratch wound healing assay, transwell invasion assay were used to explore the biological function of KRT16P3. Western blot and qRT-PCR were used to determine the expression of epithelial-mesenchymal transition (EMT) markers. The pathway changes after KRT16P3 knockdown were detected by Western blot.

RESULTS

We found KRT16P3 expression is significantly upregulated in TSCC tissues and positively associated with advanced clinicopathological features of TSCC patients, and it may serve as a poor prognostic factor. Functionally, KRT16P3 knockdown inhibits proliferation, migration, invasion and promotes apoptosis of TSCC cells. Furthermore, we also revealed that KRT16P3 knockdown suppresses EMT and JAK2/STAT3 signaling pathway.

CONCLUSION

Our results validated that KRT16P3 can modulate the malignant progression, EMT process, and JAK2/STAT3 signaling pathway of TSCC, which might also serve as a novel prognostic biomarker and an attractive target for TSCC patients.

Long Non-Coding RNA NKILA Reduces Oral Squamous Cell Carcinoma Development Through the NF-KappaB Signaling Pathway

Objective:

Emerging studies have identified that long non-coding RNAs (lncRNAs) play critical roles in cancer development. This study aims to explore the mechanism of NF-KappaB (NF-κB) interacting lncRNA (NKILA) in the pathological process of oral squamous cell carcinoma (OSCC).

Methods:

NKILA expression in OSCC tissues, paracancerous tissues, and normal human oral keratinocytes and OSCC cell lines was detected using RT-qPCR. KB cells were selected for the follow-up experiments. The role of NKILA in cell proliferation, migration, invasion, and NF-κB signaling pathway was identified using the gain- and loss-of function of NKILA in OSCC cells. Additionally, the role of NKILA in vitro was determined by inducing xenograft tumors in nude mice.

Results:

NKILA was poorly expressed in OSCC tissues and cells. Cell proliferation, invasion and migration, tumor volume and weight were significantly suppressed in cells with overexpressed NKILA, while silencing NKILA led to opposite trends. Moreover, the protein levels of p-IκBα and nuclear-p65 were markedly decreased, while the levels of IκBα and cytoplasm-p65 were enhanced in cells with overexpressed NKILA.

Conclusion:

This study provided evidence that NKILA could reduce proliferation, invasion and migration of OSCC cells through inhibiting the NF-κB signaling pathway. The findings may offer new insights for OSCC prevention and treatment.

Long Non-Coding RNA (lncRNA) Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) Promotes Cell Proliferation and Migration by Regulating miR-143-3p and MAGE Family Member A9 (MAGEA9) in Oral Squamous Cell Carcinoma

Background

lncRNA MALAT1 is one of the most widely studied lncRNAs associated with various human cancers. The present study explored the functions and potential regulatory mechanisms of MALAT1 in oral squamous cell carcinoma (OSCC).

Material/Methods

We assessed levels of MALAT1, miR-143-3p, and MAGEA9 expression in OSCC tissues and cell lines by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assay. Proliferation and migration of CAL-27 cells were detected via CCK-8 and transwell assays, respectively. To study the relationships among MALAT1, miR-143-3p, and MAGEA9, we performed dual-luciferase assay and assessed the results using Spearman correlation analysis.

Results

QRT-PCR results showed that MALAT1 and MAGEA9 were expressed at higher levels and miR-143-3p was expressed at lower levels in OSCC tissues. Dramatic suppression of cell proliferation and migration abilities were caused by MALAT1 knockdown or miR-143-3p overexpression in CAL-27 cells. MALAT1 directly interacted with and negatively regulated miR-143-3p. Moreover, MAGEA9 was validated as a miR-143-3p target gene and was found to be negatively regulated by it. MALAT1 knockdown suppressed MAGEA9 protein expression and had the same effect as MAGEA9 knockdown. Additionally, MAGEA9 knockdown inhibited CAL-27 cell proliferation and migration abilities. Finally, in OSCC tissues, MALAT1 and miR-143-3p expression were negatively correlated and MALAT1 was positively correlated with MAGEA9 expression, while an inverse correlation between MAGEA9 and miR-143-3p expression was observed.

Conclusions

Taken together, our results suggest that MALAT1 functions as a competing endogenous RNA (ceRNA) in promoting OSCC cell proliferation and migration abilities through the miR-143-3p/MAGEA9 axis, thus providing new therapeutic targets for treatment of OSCC.

The diagnostic and prognostic utility of insulin growth factor of squamous cell carcinoma in oral cavity

Objective:

The present study was conducted to find the utility of insulin growth factors (IGFs) as diagnostic and prognostic biochemical parameters in patients suffering from squamous cell carcinoma of oral cavity.

Materials and Methods:

A total of 360 male and female patients diagnosed with precancerous conditions (PCC) and oral squamous cell carcinoma (OSCC) of Stage I to IV were selected for the present study. Patients were interviewed using a structured questionnaire to ascertain their demographic and medical history. After completing the history and physical examination, patients were subjected to routine blood investigations along with determining insulin growth factor (IGF-1, IGFBP-3) levels. The data obtained were then subjected to statistical analysis using SPSS 20.0 version.

Results:

The mean values of IGF-1, insulin-like growth factor-binding protein-3 (IGFBP-3), and ratio of IGF-1 and IGFBP-3 were obtained. The intergroup comparison was done between PCC and all the stages of OSCC for all the IGFs. The result obtained was found to be statistically significant (P < 0.05).

Conclusion:

The present study concluded that a positive correlation was observed for various insulin growth factors (IGF-1, IGFBP-3; and ratio of IGF-1 and IGFBP-3) between OSCC and PCC such as erythroplakia and oral submucous fibrosis. Thus, the study highlighted the use of IGFs as diagnostic and prognostic parameters in patients suffering from cancerous conditions.

The circEPSTI1/mir-942-5p/LTBP2 axis regulates the progression of OSCC in the background of OSF via EMT and the PI3K/Akt/mTOR pathway

Oral squamous cell carcinoma (OSCC) in the background of oral submucous fibrosis (OSF) caused by areca nut chewing has a high incidence in Asia-Pacific countries. However, the molecular mechanism remains unclear. Here, we performed circRNA microarray analysis to screen the circRNA expression profiles in OSCC and OSF. We identified circEPSTI1 as a circRNA with consistent, sequential upregulation from normal buccal mucosa (NBM) to OSF to OSCC. Functionally, circEPSTI1 significantly promoted OSCC cell proliferation and invasion, as evidenced by the CCK8, colony formation, wound healing, and transwell assays with circEPSTI1 overexpression and silencing. OSCC patients with circEPSTI1^high status exhibited poor prognoses. CircEPSTI1 sponged miR-942-5p and accelerated epithelial-mesenchymal transition (EMT) to increase LTBP2 expression in OSCC through phosphorylation of PI3K/Akt/mTOR signaling pathway components. Blocking the PI3K/Akt/mTOR signaling pathway with the dual PI3k/mTOR inhibitor BEZ235 reversed OSCC progression induced by overexpression of circEPSTI1 and LTBP2. Collectively, these results indicate that the circEPSTI1/miR-942-5p/LTBP2 axis affects OSCC cell proliferation and invasion via the acceleration of EMT and the phosphorylation of PI3K/Akt/mTOR signaling pathway components. CircEPSTI1 may be an independent diagnostic and prognostic marker and a potential therapeutic target for OSCC patients with OSF.

Awareness of Oral Cancer Among Dental Patients in Mecca, Saudi Arabia

Background:

Oral Cancer (OC) is a serious health problem affecting the oral cavity, which may lead to death. Alcohol, tobacco, and chewing betel are the main risk factors. Early diagnosis and adequate knowledge of OC may improve the survival rate.

Objective:

This study aimed to assess the knowledge about oral cancer among dental patients in Mecca.

Methods:

A cross-sectional study was conducted in the dental clinics of Mecca. Interviewer-administered questionnaires were distributed to 416 respondents aged 18 or older, who spoke Arabic or English, had no history of OC, and participated voluntarily. The questionnaire consisted of three sections. The first regarded demographical data, the second measured knowledge about OC, and the third was concerned with education regarding OC provided by health-care providers. The interviewers also educated the participants by handing brochures with information about OC.

Results:

Knowledge about OC among dental patients in Mecca was found to be significantly low. Only 102 of the 416 participants (24.5%) had any knowledge. Only 3.4% of all participants had been educated about OC by their health-care providers.

Conclusion:

The results of this study show a considerable lack of general knowledge about OC among dental patients in Mecca. Health programs should be developed to raise the community’s awareness.

Upregulation of long non-coding RNA FOXD2-AS1 promotes progression and predicts poor prognosis in tongue squamous cell carcinoma

BACKGROUND

Accumulating evidences suggest that lncRNA FOXD2-AS1 plays an important role in tumor progression, however, its function in tongue squamous cell carcinoma (TSCC) remains unknown. This research aims to investigate the function and mechanism of FOXD2-AS1 in the modulation of tongue squamous cell carcinoma progression.

METHODS

Expression of FOXD2-AS1 was detected in TSCC tissues and TCGA data. Receiver operating characteristic curves (ROCs) analysis and bioinformatic analysis of TCGA data were performed to investigate the role of FOXD2-AS1 in TSCC prognosis. After siRNA-mediated downregulation of FOXD2-AS1, wound healing assay, Transwell migration and invasion assays, and MTS proliferation assay were conducted to explore the effects that FOXD2-AS1 exerted on SCC-9 and CAL-27 cell lines. Western blotting was performed to detect the downstream protein changes.

RESULTS

Compared to the normal tissues and samples, FOXD2-AS1 significantly highly expressed in TSCC tissues and in TSCC samples of TCGA data, and high expression of FOXD2-AS1 was associated with lymphatic metastasis and poor TNM stages. ROC analysis and bioinformatic analysis of TCGA data further suggested that high expression of FOXD2-AS1 was associated with TSCC poor prognosis. Downregulation of FOXD2-AS1 inhibited the migration and invasion of SCC-9 and CAL-27 cell lines. Western blotting showed that the expression of p-p44 and p-p65 downregulated after FOXD2-AS1 knockdown.

CONCLUSION

High expression of FOXD2-AS1 promotes TSCC progression through modulating NF-kB and ERK MAPK signaling pathways and is associated with TSCC poor prognosis, it could be a novel therapeutic target and prognostic biomarker for TSCC.

Porphyromonas gingivalis Promotes Immunoevasion of Oral Cancer by Protecting Cancer from Macrophage Attack

The relationship of Porphyromonas gingivalis and oral squamous cell carcinoma (OSCC) has been studied for several years. Previous studies have focused on the direct effect of P. gingivalis on the activities of primary epithelial cells and OSCC cells. However, the immune system is responsible for mediating cancer development, whether P. gingivalis can affect oral cancer immunity has seldom been explored to date. In this study, we investigated the role of P. gingivalis in the immunoevasion of OSCC. We evaluated the effect of P. gingivalis on the phagocytosis of Cal-27 cells (OSCC cell line) by bone marrow-derived macrophages in vitro and studied the effect of P. gingivalis on the growth of OSCC and the polarization of tumor-associated macrophages in vivo. We found that P. gingivalis was able to inhibit the phagocytosis of Cal-27 cells by macrophages, and membrane-component molecules of P. gingivalis, such as proteins, were speculated to be the effector components. In addition, sustained infection with antibiotics-inactivated P. gingivalis promoted OSCC growth in mice and induced the polarization of macrophages into M2 tumor-associated macrophages, which mainly display protumor properties. Transcriptome analysis and quantitative RT-PCR revealed that P. gingivalis infection upregulated the expression of genes encoding protumor molecules in Cal-27 cells (suprabasin, IL-1R2, and CD47) and in macrophages (IL-1α, CCL-3, and CCL-5). Our in vitro and in vivo data suggest that P. gingivalis can promote immunoevasion of oral cancer by protecting cancer from macrophage attack. To our knowledge, the present study reveals a novel mechanism by which P. gingivalis promotes OSCC development.

Chemopreventive activity of Tualang honey against oral squamous cell carcinoma-in vivo

OBJECTIVE

The aim of this study was to evaluate the chemopreventive activity of Malaysian jungle Tualang honey (TH) after oral carcinogenesis induced with 4-nitroquinoline 1-oxide (4 NQO).

STUDY DESIGN

A total of 28 male Sprague-Dawley (SD) rats were distributed into 4 groups as follows: group 1 (nontreated group); group 2 (control), which received 4 NQO during 8 weeks in drinking water only; and groups 3 and 4, which received 4 NQO for 8 weeks in drinking water and treated with TH 1000 mg/kg and 2000 mg/kg by oral gavage for 10 weeks. All rats from all experiments were sacrificed after 22 weeks, and the incidence of oral neoplasms and histopathologic changes were microscopically evaluated. Moreover, immunohistochemical expression was analyzed in tongue specimens by using image analysis software. The expression of particular genes associated with oral cancer were assessed by using RT² Profiler PCR Array (Qiagen, Germantown, MD).

RESULTS

TH significantly reduced the incidence of oral squamous cell carcinoma (OSCC) and suppressed cancer cell proliferation via diminishing the expression of CCND1, EGFR, and COX-2. Furthermore, TH preserved cellular adhesion (epithelial polarity) through overexpression of β-catenin and e-cadherin and inhibited the OSCC aggressiveness by downregulating TWIST1 and RAC1.

CONCLUSIONS

Our data suggest that TH exerts chemopreventive activity in an animal model in which oral cancer was induced by using 4 NQO.

Malignant transformation of oral leukoplakia is associated with macrophage polarization

Background

Most oral squamous cell carcinomas (OSCC) occur on the basis of oral leukoplakias (OLP). The histologic degree of dysplasia is insufficient for the prediction of OLP malignant transformation. Immunologic parameters are gaining importance for prognostic assessment and therapy of cancer. M2 polarized macrophages were shown to be associated with OSCC progression and inferior prognosis. The current study aims to answer the question if OLP with malignant transformation into OSCC within 5 years differ from OLP without transformation regarding macrophage infiltration and polarization.

Methods

201 specimens (50 transforming OLP, 53 non-transforming OLP, 49 corresponding OSCC and 49 healthy oral mucosa controls) were processed for immunohistochemistry. Samples were stained for CD68, CD163 and CD11c expression, completely digitalized and computer-assisted cell counting was performed. Epithelial and subepithelial compartments were differentially assessed. Groups were statistically compared using the Mann–Whitney U-test. A cut-off point for the discrimination of transforming and non-transforming OLP was determined and the association between macrophage infiltration and malignant transformation was calculated using the Chi-square test (χ² test).

Results

Macrophage infiltration and M2 polarization in OLP with malignant transformation within 5 years was significantly increased compared to OLP without malignant transformation (p < 0.05). OSCC samples showed the highest macrophage infiltration and strongest M2 polarization (p < 0.05). Additionally, transforming OLP revealed a significant shift of macrophage infiltration towards the epithelial compartment (p < 0.05). χ² test revealed a significant association of increased macrophage infiltration with malignant transformation (p < 0.05).

Conclusion

Immunological changes precede malignant transformation of OLP. Increased macrophage infiltration and M2 polarization was associated with the development of oral cancer in OLP. Macrophage infiltration could serve as predictive marker for malignant transformation.

Long non-coding RNA RBM5-AS1 promotes the aggressive behaviors of oral squamous cell carcinoma by regulation of miR-1285-3p/YAP1 axis

The human genome encodes far more long non-coding RNA (lncRNA) genes than protein coding genes. However, the function of majority of the lncRNAs is poorly understood. Numerous lncRNAs were aberrantly expressed in various cancers and found to be associated with development and progression of cancer. Little is known about the role of lncRNAs in oral squamous cell carcinoma (OSCC). In this study, we identified lncRNA RBM5-AS1 to be highly expressed in OSCC tumor tissues and cancer cell lines. RBM5-AS1 promotes the proliferation, migration, and invasion of OSCC cells in vitro. We also found that RBM5-AS1 regulates the level of miR-1285-3p as a competitive endogenous RNA (ceRNA), therefore regulate the expression level of an oncogene-YAP1, a target of miR-1285-3p. The information obtained in this study is valuable for understanding the regulatory mechanism of lncRNA in the development of OSCC and for developing new strategies for the diagnosis and treatment of OSCC.

Medical practitioners' educational competence about oral and oropharyngeal carcinoma: a systematic review and meta-analysis

Medical practitioners' (MP) role is pivotal in primary prevention, early diagnosis, prompt referral and effective management of oral and oropharyngeal carcinomas (OC/OPC), which raises the importance of their effective OC/OPC education at all levels of medical education. The purpose of this systematic review was to summarise the available scientific evidence about their educational competence in dealing with OC/OPC. We made a systematic search of papers in the English language in MEDLINE, Scopus, Cochrane Library CENTRAL and CINAHL databases from their inception until December 2018. Overall, 23 cross-sectional and three interventional studies have been selected for the systematic review and 18 of these were included in the meta-analyses. Excluding tobacco use (synthesised estimate of 95% of respondents identified tobacco as an OC/OPC risk factor, 95% CI of synthesised estimate 92% to 97%) and alcohol consumption (65%, 95%CI 52% to 77%), less than half of MP (approximately) were knowledgeable about important OC/OPC risk factors including human papilloma virus (42%, 95% CI 30% to 54%), poor diet (34%, 95% CI 17% to 54%), and advancing age (45%, 95% CI 21% to 70%). There was a low to moderate level of awareness among MP regarding common precancerous oral lesions involving leukoplakia (56%, 95% CI 32% to 79%), erythroplakia (30%, 95% CI 8% to 58%), and oral lichen planus (13%, 95% CI 0 to 41%). Moderate knowledge was also recorded about frequent sites of OC development involving the tongue (48%, 95% CI 33% to 64%) and floor of the mouth (37%, 95% CI 19% to 57%). Most MP enquired about tobacco use (86%, 95% CI 74% to 96%), and alcohol consumption (73%, 95% CI 47% to 94%) during history taking, and expressed willingness to be given supplementary OC/OPC education (78%, 95% CI 54% to 96%), as well. With regard to the incidence of intraoral screening, 27% of MP (95% CI 12% to 46%) make an intraoral examination as a routine. Interestingly, studies from each continent yielded significantly different outcomes to some research questions in the review. From the MP's perspective, clinical time restrictions and deficiencies in organised training were recognised as the main barriers towards their OC/OPC educational competence. The findings of this systematic review indicated the existence of deficiencies in knowledge and misconceptions, neglected preventive responsibilities, and associated barriers towards OC/OPC. A need for improved OC/OPC training at all levels of medical education is required to increase competence worldwide.

Comparison of Squamous Cell Carcinoma of the Tongue between Young and Old Patients

Background

The worldwide incidence of squamous cell carcinoma of the tongue (SCCOT) in young patients has been increasing. We investigated clinicopathologic features of this unique population and compared them with those of SCCOT in the elderly to delineate its pathogenesis.

Methods

We compared clinicopathological parameters between patients under and over 45 years old. Immunohistochemical assays of estrogen receptor, progesterone receptor, androgen receptor, p53, p16, mdm2, cyclin D1, and glutathione S-transferase P1 were also compared between them.

Results

Among 189 cases, 51 patients (27.0%) were under 45 years of age. A higher proportion of women was seen in the young group, but was not statistically significant. Smoking and drinking behaviors between age groups were similar. Histopathological and immunohistochemical analysis showed no significant difference by age and sex other than higher histologic grades observed in young patients.

Conclusions

SCCOT in young adults has similar clinicopathological features to that in the elderly, suggesting that both progress via similar pathogenetic pathways.