Survival after curative surgical treatment for primary oral squamous cell carcinoma

CRISPR/Cas9-mediated knock out of ITGB6 in human OSCC cells reduced migration and proliferation ability

BACKGROUND

The treatment of oral squamous cell carcinoma (OSCC) remains challenging and survival rates have not been improved significantly over the past decades. Integrins have been recognized driving the cancer progression and high expression levels cause poor outcomes in patients afflicted with OSCC. Integrin αvβ6 and its subunit integrin beta 6 (ITGB6) were discovered to enhance the invasiveness by providing beneficial effects on downstream pathways promoting the cancer progression. The objective of this study was to establish a CRISPR/Cas9-mediated knock out of ITGB6 in the human OSCC cell line HN and investigate the effects on the migration and proliferation ability.

METHODS

ITGB6 knock out was performed using the CRISPR/Cas9-system, RNPs, and lipofection. Monoclonal cell clones were achieved by limiting dilution and knock out verification was carried out by sanger sequencing and FACS on protein level. The effects of the knock out on the proliferation and migration ability were evaluated by using MTT and scratch assays. In addition, in silico TCGA analysis was utilized regarding the effects of ITGB6 on overall survival and perineural invasion.

RESULTS

In silico analysis revealed a significant impact of ITGB6 mRNA expression levels on the overall survival of patients afflicted with OSCC. Additionally, a significantly higher rate of perineural invasion was discovered. CRISPR/Cas9-mediated knock out of ITGB6 was performed in the OSCC cell line HN, resulting in the generation of a monoclonal knock out clone. The knock out clone exhibited a significantly reduced migration and proliferation ability when compared to the wildtype.

CONCLUSIONS

ITGB6 is a relevant factor in the progression of OSCC and can be used for the development of novel treatment strategies. The present study is the first to establish a monoclonal CRISPR/Cas9-mediated ITGB6 knockout cell clone derived from an OSCC cell line. It suggests that ITGB6 has a significant impact on the proliferative and migratory capacity in vitro.

Identification of cuproptosis-related lncRNAs with the significance in prognosis and immunotherapy of oral squamous cell carcinoma

Cuproptosis, a recently characterized programmed cell death mechanism, has emerged as a potential contributor to tumorigenesis, metastasis, and immune modulation. Long non-coding RNAs (lncRNAs) have demonstrated diverse regulatory roles in cancer and hold promise as biomarkers. However, the involvement and prognostic significance of cuproptosis-related lncRNAs (CRLs) in oral squamous cell carcinoma (OSCC) remain poorly understood. Based on TCGA-OSCC data, we integrated single-sample gene set enrichment analysis (ssGSEA), the LASSO algorithm, and the tumor immune dysfunction and exclusion (TIDE) algorithm. We identified 11 CRLs through differential expression, Spearman correlation, and univariate Cox regression analyses. Two distinct CRL-related subtypes were unveiled, delineating divergent survival patterns, tumor microenvironments (TME), and mutation profiles. A robust CRL-based signature (including AC107027.3, AC008011.2, MYOSLID, AC005785.1, AC019080.5, AC020558.2, AC025265.1, FAM27E3, and LINC02367) prognosticated OSCC outcomes, immunotherapy responses, and anti-tumor strategies. Superior predictive power compared to other lncRNA models was demonstrated. Functional assessments confirmed the influence of FAM27E3, LINC02367, and MYOSLID knockdown on OSCC cell behaviors. Remarkably, the CRLs-based signature maintained stability across OSCC patient subgroups, underscoring its clinical potential for survival prediction. This study elucidates CRLs' roles in TME of OSCC and establishes a potential signature for precision therapy.

Decoding the role of miRNAs in oral cancer pathogenesis: A focus on signaling pathways

Oral cancer (OC) is the predominant type originating in the head and neck region. The incidence of OC is mostly associated with behavioral risk factors, including tobacco smoking and excessive alcohol intake. Additionally, there is a lower but still significant association with viral infections such as human papillomaviruses and Epstein-Barr viruses. Furthermore, it has been observed that heritable genetic variables are linked to the risk of OC, in addition to the previously mentioned acquired risk factors. The current absence of biomarkers for OC diagnosis contributes to the frequent occurrence of advanced-stage diagnoses among patients. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs, and circular RNAs, have been observed to exert a significant effect on the transcriptional control of target genes involved in cancer, either through direct or indirect mechanisms. miRNAs are a class of short ncRNAs that play a role in regulating gene expression by enabling mRNA degradation or translational repression at the post-transcriptional phase. miRNAs are known to play a fundamental role in the development of cancer and the regulation of oncogenic cell processes. Notch signaling, PTEN/Akt/mTOR axis, KRAS mutation, JAK/STAT signaling, P53, EGFR, and the VEGFs have all been linked to OC, and miRNAs have been shown to have a role in all of these. The dysregulation of miRNA has been identified in cases of OC and is linked with prognosis.

A novel long noncoding RNA located on the antisense strand of MAL promotes the invasion and metastasis of oral squamous cell carcinoma

OBJECTIVES

This study aims to investigate the role of the long non-coding RNA-AC103563.8 (lncRNA) in promoting oral squamous cell carcinoma (OSCC) development and to conduct preliminary research on its mechanism.

DESIGN

Microarray technology were used to screen out a lncRNA significantly upregulated in OSCC. Fluorescence in situ hybridization was used to analyze the position of lncRNA-AC103563.8 in cells. A Cal-27 cell line with knockout of the lncRNA-AC103563.8 gene was constructed. Transwell assay and tumor xenograft experiment was used to determine the metastasis and invasion of the cell. Detection of mutations in genes encoding myelin and lymphocyte proteins (MAL) by pyrosequencing. Identification of RNA-Binding Proteins by Mass Spectrometry (ChIRP-MS) experiments were carried out to enrich the proteins that directly bind to lncRNA-AC103563.8. Bioinformatics was used to analyze the target proteins. Some of the selected proteins were verified by parallel reaction monitoring (PRM) to confirm their binding to lncRNA-AC103563.8.

RESULTS

lncRNA-AC103563.8 is upregulated in OSCC tissue and the presence of lncRNA-AC103563.8 in both the nucleus and the cytoplasm. lncRNA-AC103563.8 promoted OSCC cell invasion and metastasis. Methylation occurs in MAL gene promoter. ChIRP-MS identified 330 proteins binding to lncRNA-AC103563.8, and bioinformatics analysis showed that they were involved in a variety of biological processes. PRM experiments confirmed some protein directly bound to lncRNA-AC103563.8.

CONCLUSION

lncRNA-AC103563.8 is a functional lncRNA that promotes OSCC development by acting on MAL or interacting with other tumor-related proteins. This study also indicates that this lncRNA may exert regulatory functions in OSCC and is a potential target for OSCC therapy.

Role of Stromal Fibroblast-Induced WNT7A Associated with Cancer Cell Migration Through the AKT/CLDN1 Signaling Axis in Oral Squamous Cell Carcinoma

Wnt signaling plays a crucial role in the progression of various cancers, including oral squamous cell carcinoma (OSCC). However, the tumor microenvironment (TME) regulating Wnt signaling has not yet been fully elucidated. In this study, we investigated whether cancer-associated fibroblasts (CAFs), the primary components of the TME, activate Wnt signaling and promote tumor progression in OSCC. We conducted a Transwell coculture assay using human OSCC cell lines and normal human dermal fibroblasts (NHDFs). NHDFs stimulated WNT7A expression in several OSCC cell lines, especially HO-1-N-1 and HSC-5. An immunohistochemical study using 122 human OSCC samples indicated that high WNT7A expression in tumor cells was significantly associated with invasion depth and poor prognosis. Moreover, WNT7A expression in OSCC cells was positively correlated with α-smooth muscle actin expression in CAFs. WNT7A knockdown in OSCC cells demonstrated that OSCC cells cocultured with NHDFs significantly promoted tumor cell migration and invasion, which was dependent on WNT7A expression in OSCC cells. We also isolated HSC-5 cells from the coculture and conducted microarray analysis to investigate the factors that promote tumor progression induced by WNT7A. Among the various differentially expressed genes, we identified a downregulated gene encoding CLDN1 and confirmed that WNT7A negatively regulated CLDN1 expression in OSCC cells and CLDN1 knockdown in OSCC cells promoted their migration. Phosphokinase array analysis showed that WNT7A activates protein kinase B (AKT) phosphorylation. Activating AKT signaling using the SC79 agonist induced CLDN1 downregulation in OSCC cells. In the coculture assay, the AKT inhibitor MK2206 significantly recovered CLDN1 expression downregulated by WNT7A, resulting in OSCC cell migration suppression. These results suggest that CAFs stimulate OSCC cells to produce WNT7A, following CLDN1 expression downregulation by activating AKT signaling, promoting cancer cell migration. These findings highlight the importance of molecular therapies targeting the TME in OSCC.

MiRNA-related metastasis in oral cancer: moving and shaking

Across the world, oral cancer is a prevalent tumor. Over the years, both its mortality and incidence have grown. Oral cancer metastasis is a complex process involving cell invasion, migration, proliferation, and egress from cancer tissue either by lymphatic vessels or blood vessels. MicroRNAs (miRNAs) are essential short non-coding RNAs, which can act either as tumor suppressors or as oncogenes to control cancer development. Cancer metastasis is a multi-step process, in which miRNAs can inhibit or stimulate metastasis at all stages, including epithelial-mesenchymal transition, migration, invasion, and colonization, by targeting critical genes in these pathways. On the other hand, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two different types of non-coding RNAs, can regulate cancer metastasis by affecting gene expression through cross-talk with miRNAs. We reviewed the scientific literature (Google Scholar, Scopus, and PubMed) for the period 2000-2023 to find reports concerning miRNAs and lncRNA/circRNA-miRNA-mRNA networks, which control the spread of oral cancer cells by affecting invasion, migration, and metastasis. According to these reports, miRNAs are involved in the regulation of metastasis pathways either by directly or indirectly targeting genes associated with metastasis. Moreover, circRNAs and lncRNAs can induce or suppress oral cancer metastasis by acting as competing endogenous RNAs to inhibit the effect of miRNA suppression on specific mRNAs. Overall, non-coding RNAs (especially miRNAs) could help to create innovative therapeutic methods for the control of oral cancer metastases.

circNFATC3 facilitated the progression of oral squamous cell carcinoma via the miR-520h/LDHA axis

The aim of this study was to verify the effects of circular RNA nuclear factor of activated T-cells, cytoplasmic 3 (circNFATC3), in oral squamous cell carcinoma (OSCC) development. The levels of circNFATC3, microRNA-520h (miR-520h), and lactate dehydrogenase A (LDHA) were measured by qRT-PCR and western blot analysis. The cellular functions were assessed by using commercial kits, MTT assay, EdU assay, flow cytometry analysis, and transwell assay. The interactions between miR-520h and circNFATC3 or LDHA were confirmed by dual-luciferase reporter assay. Finally, the mice test was enforced to evaluate the character of circNFATC3. We observed that the contents of circNFATC3 and LDHA were upregulated and miR-520h levels were downregulated in OSCC tissues compared with those in paracancerous tissues. For functional analysis, circNFATC3 knockdown repressed the cell glycolysis metabolism, cell proliferation, migration, and invasion, although it improved cell apoptosis in OSCC cells. LDHA could regulate the development of OSCC. circNFATC3 acted as a miR-520h sponge to modulate LDHA expression. In addition, the absence of circNFATC3 subdued tumor growth in vivo. In conclusion, circNFATC3 promoted the advancement of OSCC by adjusting the miR-520h/LDHA axis.

Evaluation of tumor-infiltrating T & B lymphocytes and their association and distribution in oral squamous cell carcinoma tumor microenvironment: An in vitro immunohistochemical study

OBJECTIVE

The immune interaction between host immunity and the tumor microenvironment is complex, and a thorough understanding of tumor-infiltrating lymphocyte selection in oral cancer, including T and B cells, is urgently required. Within the tumor microenvironment, tumor cells escape immune surveillance and grow uncontrollably. The study examined the relationship and distribution of tumor-infiltrating T and B lymphocytes.

STUDY DESIGN

Retrospective data of paraffin-embedded tissue samples of 47 primary oral squamous cell carcinoma (OSCC) cases were retrieved. Hematoxylin and eosin evaluation, along with all clinicopathologic data, were collected. Immunohistochemical CD3 and CD20 markers were used and evaluated for association and distribution in given OSCC cases.

RESULTS

The intermediate type of inflammatory infiltrate was seen primarily in Well DIfferentiated Squamous cell Carcinoma grade and positive and negative lymph nodes. Compared with T-cell density, B-cell density showed an aggregate pattern rather than a scattered pattern, indicating a statistically significant association between T-cell and B-cell infiltrate. B-cell infiltrates were also found to have a statistically significant relationship with tertiary lymphoid structure.

CONCLUSIONS

A strong, positive association and correlation exists between B- and T-lymphocyte infiltration in both the stroma and the invasive front. When compared with T-cell density, B-cell density is more predominantly in aggregates.

Splice site m6A methylation prevents binding of DGCR8 to suppress KRT4 pre-mRNA splicing in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the 11th most prevalent tumor worldwide. Despite advantages of therapeutic approaches, the 5-year survival rate of patients with OSCC is less than 50%. It is urgent to elucidate mechanisms underlying OSCC progression for developing novel treatment strategies. Our recent study has revealed that Keratin 4 (KRT4) suppresses OSCC development, which is downregulated in OSCC. Nevertheless, the mechanism downregulating KRT4 in OSCC remains unknown. In this study, touchdown PCR was utilized to detect KRT4 pre-mRNA splicing, while m⁶A RNA methylation was identified by methylated RNA immunoprecipitation (MeRIP). Besides, RNA immunoprecipitation (RIP) was used to determine RNA-protein interaction. Herein, this study indicated that intron splicing of KRT4 pre-mRNA was suppressed in OSCC. Mechanistically, m⁶A methylation of exon-intron boundaries prevented intron splicing of KRT4 pre-mRNA in OSCC. Besides, m⁶A methylation suppressed the binding of splice factor DGCR8 microprocessor complex subunit (DGCR8) to exon-intron boundaries in KRT4 pre-mRNA to prohibit intron splicing of KRT4 pre-mRNA in OSCC. These findings revealed the mechanism downregulating KRT4 in OSCC and provided potential therapeutic targets for OSCC.

Metabolomic Analysis Reveals that SPHK1 Promotes Oral Squamous Cell Carcinoma Progression through NF-κB Activation

BACKGROUND

Metabolic disorders are significant in the occurrence and development of malignant tumors. Changes of specific metabolites and metabolic pathways are molecular therapeutic targets. This study aims to determine the metabolic differences between oral squamous cell carcinoma (OSCC) tissues and paired adjacent noncancerous tissues (ANT) through liquid chromatography-mass spectrometry (LC-MS). SPHK1 is a key enzyme in sphingolipid metabolism. This study also investigates the potential role of SPHK1 in OSCC.

MATERIALS AND METHODS

This study used LC-MS to analyze metabolic differences between OSCC tissues and paired ANT. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were applied to explain the significance of phospholipid metabolism pathways in the occurrence and development of OSCC. Through further experiments, we confirmed the oncogenic phenotypes of SPHK1 in vitro and in vivo, including proliferation, migration, and invasion.

RESULTS

The sphingolipid metabolic pathway was significantly activated in OSCC, and the key enzyme SPHK1 was significantly upregulated in oral cancer tissues, predicting poor OSCC prognosis. In this study, SPHK1 overexpression was associated with high-grade malignancy and poor OSCC prognosis. SPHK1 targeted NF-κB by facilitating p65 expression to regulate OSCC tumor progression and promote metastasis.

CONCLUSIONS

This study identified metabolic differences between OSCC and paired ANT, explored the carcinogenic role of overexpressed SPHK1, and revealed the association of SPHK1 with poor OSCC prognosis. SPHK1 targets NF-κB signaling by facilitating p65 expression to regulate tumor progression and promote tumor metastasis, providing potential therapeutic targets for diagnosing and treating oral tumors.

Overexpression of angiogenic factors and matrix metalloproteinases in the saliva of oral squamous cell carcinoma patients: potential non-invasive diagnostic and therapeutic biomarkers

Backgrounds

Salivary biomarkers hold huge potential for the non-invasive diagnosis of oral squamous cell carcinoma. Angiogenic factors and matrix-metalloproteinases (MMPs) are highly expressed in OSCC tissue, but their expression patterns in the saliva are unknown. This study aimed to analyze the levels of angiogenic factors and MMPs in tumor tissue and saliva of OSCC patients.

Methods

OSCC-tissue, adjacent normal tissue (ANT), saliva from OSCC patients, and healthy controls were obtained. The expression patterns of angiogenic factors and MMPs were analyzed by immunohistochemistry, protein chip array, and RT-qPCR.

Results

Results showed higher expression of ANG, ANG-2, HGF, PIGF, VEGF, MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-13, TIMP-1, and TIMP-2 in OSCC-tissues compared to the ANT. Among the overexpressed markers in OSCC-tissues, HGF, VEGF, PIGF, PDGF-BB, MMP-1, MMP-3, MMP-8, MMP-9, MMP-10, MMP-13, and TIMP-2 were significantly upregulated in the saliva of OSCC patients compared to healthy controls.

Conclusions

The levels of HGF, VEGF, PIGF, MMP-1, MMP-3, MMP-8, MMP-9, MMP-10, MMP-13, and TIMP-2 were upregulated both in OSCC tissue and saliva of OSCC patients. Bioinformatic analysis revealed the correlation of these factors with patient survival and cancer functional states in head and neck cancer, indicating these factors as possible saliva-based non-invasive diagnostic/prognostic markers and therapeutic targets of OSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09630-0.

Single-Cell Profiling Reveals Heterogeneity of Primary and Lymph Node Metastatic Tumors and Immune Cell Populations and Discovers Important Prognostic Significance of CCDC43 in Oral Squamous Cell Carcinoma

Although substantial progress has been made in biological research and clinical treatment in recent years, the clinical prognosis of oral squamous cell carcinoma (OSCC) is still not satisfactory. Tumor immune microenvironment (TIME) is a potential target, which plays an essential role in the response of anti-tumor immunity and immunotherapy. In this study, we used scRNA-seq data, revealing the heterogeneity of TIME between metastatic and primary site. We found that in the metastatic site, the content of cytotoxic T cells and classical activated macrophages (M1 macrophages) increases significantly, while alternately activated macrophages (M2 macrophages) and inflammatory cancer-associated fibroblasts (iCAFs) decrease, which may be due to the increased immunogenicity of OSCC cells in the metastatic site and the changes in some signal pathways. We also found that iCAFs may recruit alternately activated macrophages (M2 macrophages) by secreting CXCL12. Then, we described a regulatory network for communication between various TIME cells centered on OSCC cells, which can help to clarify the possible mechanism of lymph node metastasis in OSCC cells. By performing pseudotime trajectory analysis, we found that the expression CCDC43 is upregulated in more advanced OSCC cells and is an independent prognostic factor for poor living conditions. Other than this, the high expression of CCDC43 may impair the antitumor immunity of the human body and promote the metastasis of OSCC cells. Our research provides a profound insight into the immunological study of OSCC and an essential resource for future drug discovery.

Potential for reversing miR-634-mediated cytoprotective processes to improve efficacy of chemotherapy against oral squamous cell carcinoma

For advanced oral squamous cell carcinoma (OSCC), increasing sensitivity to chemotherapy is a major challenge in improving treatment outcomes, and targeting cytoprotective processes that lead to the chemotherapy resistance of cancer cells may be therapeutically promising. Tumor-suppressive microRNAs (miRNAs) can target multiple cancer-promoting genes concurrently and are thus expected to be useful seeds for cancer therapeutics. We revealed that miR-634-mediated targeting of multiple cytoprotective process-related genes, including cellular inhibitor of apoptosis protein 1 (cIAP1), can effectively increase cisplatin (CDDP)-induced cytotoxicity and overcome CDDP resistance in OSCC cells. The combination of topical treatment with miR-634 ointment and administration of CDDP was synergistically effective against OSCC tumor growth in a xenograft mouse model. Furthermore, the expression of miR-634 target genes is frequently upregulated in primary OSCC tumors. Our study suggests that reversing miR-634-mediated cytoprotective processes activated in cancer cells is a potentially useful strategy to improve CDDP efficacy against advanced OSCC.

Impact of Non-Coding RNAs on Chemotherapeutic Resistance in Oral Cancer

Drug resistance in oral cancer is one of the major problems in oral cancer therapy because therapeutic failure directly results in tumor recurrence and eventually in metastasis. Accumulating evidence has demonstrated the involvement of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in processes related to the development of drug resistance. A number of studies have shown that ncRNAs modulate gene expression at the transcriptional or translational level and regulate biological processes, such as epithelial-to-mesenchymal transition, apoptosis, DNA repair and drug efflux, which are tightly associated with drug resistance acquisition in many types of cancer. Interestingly, these ncRNAs are commonly detected in extracellular vesicles (EVs) and are known to be delivered into surrounding cells. This intercellular communication via EVs is currently considered to be important for acquired drug resistance. Here, we review the recent advances in the study of drug resistance in oral cancer by mainly focusing on the function of ncRNAs, since an increasing number of studies have suggested that ncRNAs could be therapeutic targets as well as biomarkers for cancer diagnosis.

IGF2BP2 maybe a novel prognostic biomarker in oral squamous cell carcinoma

Aim: The main of the present study was to investigate the role of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) in oral squamous cell carcinoma (OSCC) with the overarching of providing new biomarkers or potential therapeutic targets for OSCC.

Methods: We combined datasets downloaded from Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and samples collected from the clinic to evaluate the expression of IGF2BP2 in OSCC. IGF2BP2 survival analysis was respectively performed based on TCGA, GEO, and clinical samples. Correlations between IGF2BP2 expression and clinicopathological parameters were then analyzed, and signaling pathways associated with IGF2BP2 expression were identified using gene set enrichment analysis (GSEA 4.1.0). Moreover, an IGF2BP2 co-expressed gene network was constructed, followed by gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis on IGF2BP2 co-expressed genes. Finally, TIMER and CIBERSORT were used to analyze the correlations among IGF2BP2, IGF2BP2-coexpressed genes, and tumor-infiltrating immune cells (TICs).

Results: IGF2BP2 was highly expressed in OSCC and significantly correlated with overall survival of OSCC patients (P<0.01). High IGF2BP2 expression correlated with poor overall survival. The GSEA results showed that cell apoptosis-, tumor-, and immune-related pathways were significantly enriched in samples with high IGF2BP2 expression. Furthermore, GO and KEGG enrichment analyses results of IGF2BP2 co-expressed genes indicated that these genes are mainly associated with immunity/inflammation and tumorigenesis. In addition, IGF2BP2 and its co-expressed genes are associated with TICs (P<0.01).

Conclusion: IGF2BP2 may be a potential prognostic biomarker in OSCC and correlates with immune infiltrates.

A Study of the Lipidomic Profiles of the CAL-27 and HOK Cell Lines Using EMS Spectra

Objective

The aim of this study was to explore the lipidomic profiles of the CAL-27 human tongue cancer cell line and the human oral keratinocyte (HOK) cell line.

Methods

The lipidomic differences between the CAL-27 and the HOK cell lines were investigated using non-targeted high-performance liquid chromatography–mass spectrometry lipidomic analysis. The resulting data were then further mined via bioinformatics analysis technology and metabolic pathway analysis was conducted in order to map the most affected metabolites and pathways in the two cell lines.

Results

A total of 711 lipids were identified, including 403 glycerophospholipids (GPs), 147 glycerolipids, and 161 sphingolipids. Comparison of the enhanced MS (EMS) spectra of the two cell lines in positive and negative ionization modes showed the lipid compositions of HOK and CAL-27 cells to be similar. The expressions of most GP species in CAL-27 cells showed an increasing trend as compared with HOK, whereas a significant increase in phosphatidylcholine was observed (p < 0.05). Significant differences in the lipid composition between CAL-27 and HOK cells were shown as a heatmap. Through principal component analysis and orthogonal partial least squares discriminant analysis, noticeably clear separation trends and satisfactory clustering trends between groups of HOK and CAL-27 cells were identified. The numbers of specific lipid metabolites that could distinguish CAL-27 from HOK in positive and negative modes were 100 and 248, respectively. GP metabolism was the most significantly altered lipid metabolic pathway, with 4 metabolites differentially expressed in 39 hit products.

Conclusion

This study demonstrated the potential of using untargeted mass spectra and bioinformatics analysis to describe the lipid profiles of HOK and CAL-27 cells.

The role of non-coding RNAs in drug resistance of oral squamous cell carcinoma and therapeutic potential

Oral squamous cell carcinoma (OSCC), the eighth most prevalent cancer in the world, arises from the interaction of multiple factors including tobacco, alcohol consumption, and betel quid. Chemotherapeutic agents such as cisplatin, 5-fluorouracil, and paclitaxel have now become the first-line options for OSCC patients. Nevertheless, most OSCC patients eventually acquire drug resistance, leading to poor prognosis. With the discovery and identification of non-coding RNAs (ncRNAs), the functions of dysregulated ncRNAs in OSCC development and drug resistance are gradually being widely recognized. The mechanisms of drug resistance of OSCC are intricate and involve drug efflux, epithelial-mesenchymal transition, DNA damage repair, and autophagy. At present, strategies to explore the reversal of drug resistance of OSCC need to be urgently developed. Nano-delivery and self-cellular drug delivery platforms are considered as effective strategies to overcome drug resistance due to their tumor targeting, controlled release, and consistent pharmacokinetic profiles. In particular, the combined application of new technologies (including CRISPR systems) opened up new horizons for the treatment of drug resistance of OSCC. Hence, this review explored emerging regulatory functions of ncRNAs in drug resistance of OSCC, elucidated multiple ncRNA-meditated mechanisms of drug resistance of OSCC, and discussed the potential value of drug delivery platforms using nanoparticles and self-cells as carriers in drug resistance of OSCC.

The impact of intraoperative frozen section analysis on final resection margin status, recurrence, and patient outcome with oral squamous cell carcinoma

Background

The objective of this study was to evaluate the diagnostic value of intraoperative frozen section analysis (IFSA) of tumor bed margins in patients with oral squamous cell carcinoma (OSCC).

Methods

This retrospective study includes 194 primary OSCC cases. The impact of intraoperative information by IFSA on final margin status, local recurrence, and disease-specific survival were analyzed.

Results

IFSA revealed a 50% sensitivity and a 100% specificity, with a positive and negative predictive value of 100% and 89.1%, respectively. In 19 cases, margins were rated positive by IFSA and remained positive in eight cases (42.1%), despite immediate re-resection. This constellation led to higher recurrence and lower survival rates than in cases with consecutive R0 status (each p = 0.046). Positive margins in IFSA were associated with closer final margins (p = 0.022) and early recurrences (p = 0.050).

Conclusions

Achieving instant R0 status has a crucial impact on disease recurrence and patient survival. IFSA falls short to ensure secure definite surgical margins. Thus, improved intraoperative diagnostic information on the location and extent of OSCC could support patient treatment.

Clinical relevance

Considering that patient survival has not improved despite progress in surgical and adjuvant therapy, the process and outcome of IFSA was scrutinized as one part of the treatment concept.

Screening and validation of plasma long non-coding RNAs as biomarkers for the early diagnosis and staging of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), characterized by a high recurrence rate, a poor prognosis and high morbidity, is the most prevalent malignancy of the oral cavity. The aberrant expression of long non-coding RNAs (lncRNAs) may lead to the development of various diseases, including cancer. Delayed diagnosis is the main reason for the poor prognosis. Therefore, the present study aimed to investigate the differential expression profiles of plasma lncRNAs in OSCC in order to screen target lncRNAs as biomarkers for the early diagnosis and staging of OSCC. The expression profiles of lncRNAs and mRNAs in OSCC were analyzed by microarray analysis. A total of 14 candidate lncRNAs were selected and analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) using the array homologous samples. Subsequently, 4 target lncRNAs were measured by RT-qPCR in a large cohort, including 28 cases with TNM I/II [early-stage squamous cell carcinoma (ESCC) group], 36 cases with TNM III/IV [advanced-stage squamous cell carcinoma (ASCC) group], 16 cases with dysplasia [oral premalignant lesion (OPL) group] and 16 healthy controls (H group). Receiver operating characteristic (ROC) curves and logistic regression analysis were used to evaluate the diagnostic effects of the combined lncRNAs. In total, 6,606 differentially expressed lncRNAs and 4,196 mRNAs were identified in OSCC. The expression trend of the 14 candidate lncRNAs was consistent with the microarray data. The expression level of ENST00000412740, NR_131012, ENST00000588803 and NR_038323 exhibited significant differences in the H, OPL, ESCC and ASCC groups (P<0.05). ROC curve and logistic regression analyses revealed that the diagnostic efficacy of the combined lncRNAs was more prominent than that of a single lncRNA, particularly in the ESCC and ASCC groups. In conclusion, the present study identified the differential expression profiles of plasma lncRNAs in OSCC and demonstrated that ENST00000412740, NR_131012, ENST00000588803 and NR_038323 may be promising biomarkers for the early diagnosis and staging of OSCC. These findings may provide novel targets for the early diagnosis and staging of OSCC, which may provide an objective basis for clinical decision-making.

YAP signaling induces PIEZO1 to promote oral squamous cell carcinoma cell proliferation

Most cancer cells are exposed to altered extracellular environments, such as an increase in extracellular matrix (ECM) stiffness and soluble signals consisting of growth factors and cytokines. It is therefore conceivable that changes in tumor extracellular environments affect tumor cell behavior. The Hippo pathway reportedly responds to the extracellular environment and regulates the nuclear localization of the transcription co-activator, yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Inactivation of the Hippo pathway with nuclear translocation of YAP/TAZ stimulates cell proliferation. Its pathway also regulates gene expression, but the precise molecule(s) meditating the cell-proliferating effect of YAP signaling on oral squamous cell carcinoma (OSCC) is unclear. First, we examined the effects of YAP signaling on OSCC tumorigenesis. Loss-of-function experiments using siRNA or an inhibitor, and immunohistochemical analyses of tissue specimens obtained from OSCC patients demonstrated that YAP signaling was involved in OSCC cell proliferation. Second, we identified Piezo-type mechanosensitive ion channel component 1 (PIEZO1), a Ca²⁺ channel, as a transcriptional target of YAP signaling and showed that elevated PIEZO1 was required for PIEZO1 agonist-dependent Ca²⁺ entry and cell proliferation in OSCC cells. Experiments using three-dimensional and suspension culture revealed that PIEZO1 was involved in OSCC cellular growth. Finally, YAP overexpression in the nucleus and/or cytoplasm was immunohistochemically detected in tumor lesions with frequent expression of both PIEZO1 and Ki-67, but not in non-tumor regions of OSCC specimens. These results suggest that the YAP/PIEZO1 axis promotes OSCC cell growth. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

LncRNA NEAT1 mediates progression of oral squamous cell carcinoma via VEGF-A and Notch signaling pathway

BACKGROUND

lncRNAs and VEGF have been shown to have close connections with oral squamous cell carcinoma (OSCC). We explored the interaction between lncRNA NEAT1 and VEGF-A in OSCC.

METHODS

RT-qPCR was implemented to measure levels of lncRNA NEAT1 and VEGF-A in OSCC cell lines and normal cell lines. Cell functions then were checked after regulating the expressions of lncRNA NEAT1 and VEGF-A separately. Cell viabilities were examined with CCK-8 and apoptosis rate was checked with flow cytometry. Meanwhile, EMT-related genes E-cadherin, N-cadherin, Vimentin, and Snail and Notch signaling genes Notch1, Notch2, and Jagged were evaluated by RT-qPCR. IMR-1 was applied for impeding Notch signaling pathway. Later, cell viabilities, apoptosis, and EMT were assessed.

RESULTS

Expressions of lncRNA NEAT1 and VEGF-A were both increased significantly in OSCC cell lines especially in TSCC1 cell line. Suppression of lncNRA NEAT1 was associated with lower cell viabilities and EMT and higher apoptosis rate in the TSCC1 cell line. Meanwhile, knockdown of VEGF-A significantly repressed cell viabilities and EMT in the TSCC1 cell line. Magnifying functions of inhibited lncRNA NEAT1 Notch signaling pathway was obviously activated with overexpressions of lncRNA NEAT1 and VEGF-A. Adding IMR-1 significantly downregulated cell viabilities and EMT and sharply increased apoptosis in the context of lncRNA NEAT1 and VEGF-A overexpression.

CONCLUSION

LncRNA NEAT1 may upregulate proliferation and EMT and repress apoptosis through activating VEGF-A and Notch signaling pathway in vitro, suggesting an underlying regulatory factor in OSCC. Nevertheless, further research is necessary to gain a greater understanding of lncRNA NEAT1 and connections with VEGF-A in vivo and in clinical study.

Survival outcomes after surgical treatment of oral squamous cell carcinoma

OBJECTIVE

To identify the clinicopathological parameters that influence survival in patients with oral squamous cell carcinoma, in order to allow for the development of individualized surveillance programmes and reduce the delay in diagnosis of recurrence.

MATERIALS AND METHODS

Retrospective chart review of 553 patients with a treatment-naïve primary oral squamous cell carcinoma, who underwent primarily curative intended surgery. Exclusion criteria were neoadjuvant radio(chemo)therapy, follow-up < 1 year, perioperative death, inoperable disease, synchronous multiple malignancies and inadequate information on clinicopathological parameters.

RESULTS

The clinicopathological factors that influence overall survival, disease-free survival and locoregional control were calculated. In the multivariate survival analysis, the occurrence of recurrence, presence of extracapsular spread, T- and N-classification were shown to be independent risk factors for overall survival.

CONCLUSION

The identification of these risk factors can lead to the development of individualized follow-up programmes based on risk stratification. This allows for the earliest possible diagnosis of relapse which is essential to offer the patient a realistic second treatment chance and to improve survival rates.

Long non-coding RNA SLC16A1-AS1: its multiple tumorigenesis features and regulatory role in cell cycle in oral squamous cell carcinoma

Altered expressions of long non-coding RNAs (lncRNAs) are potential cancer prognostic biomarkers that play a critical role in the development of tumorigenesis and metastasis of cancer. However, the relationship between the expression of lncRNAs in oral squamous cell carcinoma (OSCC) and the diagnosis, progression, and prognosis of OSCC has not been thoroughly elucidated. To identify the differentially expressed lncRNAs between OSCC tissue and normal tissue, RNA-Seq data were used. lncRNA SLC16A1-AS1 was significantly highly expressed in OSCC samples than that in normal samples. Systematic bioinformatics analysis revealed that SLC16A1-AS1 was associated with histological tumor grades and overall survival status, as well as copy number variation, somatic mutation, tumor mutation burden, tumor stemness, tumor microenvironment and infiltrating immune cells. According to three advanced bioinformatic algorithms prediction (WGCNA, GSEA and GSVA), SLC16A1-AS1 played an essential role in OSCC proliferation and its biological function was related to cell-cycle regulation. Loss-of-function experiments were performed to determine the biological functions of SLC16A1-AS in OSCC cells. Silencing SLC16A1-AS1 significantly reduced the cell proliferation rate and colony-forming ability in both CAL27 and SCC25 cell lines. Flow cytometry and western blot analysis revealed that SLC16A1-AS1 silencing induced G0/G1 cell cycle arrest and inhibited the expression of cyclin D1 in both CAL27 and SCC25 cells. In conclusion, our study comprehensively investigated the role of the lncRNA SLC16A1-AS1 in OSCC growth and proved that it may serve as a new diagnostic indicator and a new target for the treatment of OSCC.

Long noncoding RNA UCA1 promotes cell growth, migration, and invasion by targeting miR-143-3p in oral squamous cell carcinoma

BACKGROUND

The long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) is dysregulated in many types of tumors; however, its role in oral squamous cell carcinoma (OSCC) remains unclear. This study aims to determine the effect of lncRNA UCA1 on OSCC.

METHODS

Fifty-six paired OSCC and adjacent nontumorous tissues were collected and the levels of UCA1, miR-143-3p, and MYO6 in the tissues were evaluated by qRT-PCR. In in vitro experiments, cell viability, migration, and invasion were measured by, respectively, performing CCK-8, wound healing, and transwell assays. The target relationships among UCA1, miR-143-3p, and MYO6 were verified by dual-luciferase assay. Western blot and immunohistochemistry were carried out to determine the protein levels. Xenograft mouse model was established to explore the effects of UCA1 in vivo.

RESULTS

Levels of UCA1 and MYO6 were increased significantly in OSCC, while the level of miR-143-3p was decreased compared with the adjacent nontumorous tissues. UCA1 promoted OSCC cell growth, migration, and invasion both in vitro and in vivo, while miR-143-3p reversed the progression. MYO6 was validated as a target for miR-143-3p, and MYO6 overexpression reversed the effects of miR-143-3p mimic on OSCC cells.

CONCLUSION

LncRNA UCA1 contributes to the proliferation and metastasis of OSCC cells by targeting miR-143-3p and upregulating its downstream gene MYO6. UCA1 could serve as a promising novel target therapy for treatment of OSCC.

The repertoire of tumor-infiltrating lymphocytes within the microenvironment of oral squamous cell carcinoma reveals immune dysfunction

BACKGROUND

The role of tumor-infiltrating lymphocytes (TILs) in the immune remodeling of tumor microenvironments (TME) in oral squamous cell carcinoma (OSCC) remains controversial. In this study, we pursued a comprehensive characterization of the repertoire of TILs and then analyzed its clinical significance and potential prognostic value.

METHODS

Fresh tumor tissue samples and peripheral blood from 83 OSCC patients were collected to comprehensively characterize the phenotypes and frequencies of TILs by flow cytometry. Archived paraffin-embedded tissues derived from 159 OSCC patients were analyzed by immunohistochemistry to further assess the TIL repertoire. The clinical significance of TILs and their potential prognostic value were further analyzed.

RESULTS

A series of unique features of TILs were observed. IL-17 was highly expressed in betel nut chewers, and CD20 was abundantly expressed in patients who did not drink alcohol; high expression of CD138, PD-L1, and Foxp3 was associated with poor prognosis. The Th17/Treg ratio was an independent prognostic factor for patient survival with greater predictive accuracy for overall survival.

CONCLUSIONS

Our results suggest an antigen-driven immune response; however, the immune dysfunction within the microenvironment in OSCC and the Th17/Treg balance may play important roles in the modulation of antitumor immunity.

LncRNA PVT1 Enhances Proliferation and Cisplatin Resistance via Regulating miR-194-5p/HIF1a Axis in Oral Squamous Cell Carcinoma

Background

Oral squamous cell carcinoma (OSCC) is the most frequent oral malignancy. Recent studies have revealed that long non-coding RNA (lncRNA) PVT1 plays important roles in the pathogenesis of various cancers. However, the functional roles of PVT1 in OSCC progression and cisplatin resistance have not been elucidated.

Material and Methods

In this study, PVT1 expression level in cisplatin-sensitive and cisplatin-resistant OSCC tissues and cell lines was determined using qRT-PCR. Gain-of-function and loss-of-function assays were performed to explore the biological roles of PVT1 in OSCC cell proliferation and cisplatin resistance. Western blot, luciferase reporter assay and bioinformatics analysis were employed to investigate the underlying mechanism of PVT1 in OSCC progression.

Results

Here, we found that PVT1 was frequently up-regulated in cisplatin-resistant tissues and cell lines and strongly correlated with worse overall survival. Functional studies showed that PVT1 promoted OSCC cell proliferation and cisplatin resistance. Mechanistic investigation revealed that PVT1 could positively regulate HIF1a expression via its competing endogenous RNA (ceRNA) activity on miR-194-5p. In addition, miR-194-5p conversely correlated with PVT1 and HIF1a expression in OSCC samples. More importantly, HIF1a knock-down or miR-194-5p overexpression reversed PVT1-induced promotion of OSCC cell proliferation and cisplatin resistance.

Conclusion

Our results indicated that PVT1 functions as an oncogene involved in OSCC cell proliferation and cisplatin-resistance and may serve as a novel therapeutic target for OSCC treatment.

MiR-155-5p promotes oral cancer progression by targeting chromatin remodeling gene ARID2

BACKGROUND

Dysregulation of miRNAs is associated with aberrant migration and invasion by suppressing relevant target genes in multiple cancers, including oral squamous cell carcinoma (OSCC). Accumulating evidence suggests that microRNA-155-5p is involved in carcinogenesis and tumor progression. However, the exact function and molecular mechanism of miR-155-5p in OSCC remain unclear. This study aimed to investigate the function of miR-155-5p and the molecular mechanisms underlying the influencing progression of OSCC.

METHODS

The miR-155-5p expression level in the OSCC tissues and oral cancer cell lines were determined by the qRT-PCR. Gain-of-function and knockdown approach were used to examine the effect of miR-155-5p on cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OSCC. The luciferase reporter assay was applied to confirm the AT-rich interactive domain 2 (ARID2) as a potential target of miR-155-5p, and the rescue experiment was employed to verify the roles of the miRNA-155-5p-ARID2 axis in OSCC progression. Immunohistochemical staining was used to detect ARID2 expression in another cohort sample tissues from OSCC patients.

RESULTS

MiR-155-5p was significantly upregulated in OSCC tissues and cell lines. The miR-155-5p expression level was positively correlated with tumor size, TNM stage, histological grade and lymph node metastasis of OSCC patients. Functional assays demonstrated that miR-155-5p enhanced OSCC cell proliferation, migration and invasion. Mechanistically, ARID2 was identified as a direct target and functional effector of miR-155-5p in OSCC. Furthermore, ARID2 overexpression could rescue the aberrant biological function by overexpressed miR-155-5p in OSCC cells. Notably, we showed that ARID2 could be used as an independent prognosis factor in OSCC.

CONCLUSIONS

Our results suggest that miR-155-5p facilitates tumor progression of OSCC by targeting ARID2, and miR-155-5p-ARID2 axis may be a potential therapeutic target of OSCC.

Long non-coding RNAs in Oral squamous cell carcinoma: biologic function, mechanisms and clinical implications

There is growing evidence that regions of the genome that cannot encode proteins play an important role in diseases. These regions are usually transcribed into long non-coding RNAs (lncRNAs). LncRNAs, little or no coding potential, are defined as capped transcripts longer than 200 nucleotides. New sequencing technologies have shown that a large number of aberrantly expressed lncRNAs are associated with multiple cancer types and indicated they have emerged as an important class of pervasive genes during the development and progression of cancer. However, the underlying mechanism in cancer is still unknown. Therefore, it is necessary to elucidate the lncRNA function. Notably, many lncRNAs dysregulation are associated with Oral squamous cell carcinoma (OSCC) and affect various aspects of cellular homeostasis, including proliferation, survival, migration or genomic stability. This review expounds the up- or down-regulation of lncRNAs in OSCC and the molecular mechanisms by which lncRNAs perform their function in the malignant cell. Finally, the potential of lncRNAs as non-invasive biomarkers for OSCC diagnosis are also described. LncRNAs hold promise as prospective novel therapeutic targets, but more research is needed to gain a better understanding of their biologic function.

AHNS series: Do you know your guidelines? Guideline recommendations for recurrent and persistent head and neck cancer after primary treatment

Locoregional recurrent/persistent head and neck cancer following primary treatment is a significant challenge as it is usually difficult to treat and has worse outcomes compared to the primary setting. Surgical resection of a local or regional recurrence offers the best chance of cure when feasible. Local recurrence outcomes vary by subsite with laryngeal recurrences having the best prognoses and hypopharynx having the worst. Instances of persistent neck masses following primary nonsurgical treatment can be evaluated with positron emission tomography (PET) with CT (PET-CT) when there is no definitive diagnosis of a recurrence/persistence. Reirradiation with or without chemotherapy can be considered for primary treatment when surgery is not an option, for adjuvant treatment following salvage surgery, or for palliation. Immunotherapy represents a newer class of chemotherapeutic agents. Current guidelines recommend enrollment in clinical trials especially when surgery is not an option as outcomes remain universally poor in the recurrent/persistent setting.

A Three Long Noncoding RNA-Based Signature for Oral Squamous Cell Carcinoma Prognosis Prediction

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide. Despite relative high 5-year survival rate, delayed diagnosis still hampers its prognosis improvement. Long noncoding RNA (lncRNA) has recently been demonstrated to involve in development of various cancers. This study aimed to identify a lncRNA-based signature by which we could accurately predict OSCC prognosis. We first downloaded the RNA sequencing datasets for OSCC from The Cancer Genome Atlas (TCGA) and divided samples into training set and validation set. Associations between lncRNAs' expression and OSCC overall survival (OS) were evaluated in training set. Further screening through Random Survival Forest (RSF) method identified a prognostic signature composed of three lncRNAs, including AC013268.5, RP11.65 L3.4, and RP11.15A1.7, and by which OSCC samples in training set could be divided into high-risk and low-risk group with significantly different OS (p < 0.001, hazard ratio [HR] = 1.873). Besides, reliability of the prognostic signature was confirmed in the validation set (p < 0.01, HR = 2.14). Receiver operating characteristic curve analysis showed the superiority of the signature in OSCC prognosis prediction than other clinical characteristics. Gene set enrichment analysis indicated that high-risk score was closely associated with metabolism and spliceosome related pathways. Our findings suggest that lncRNA should be an important biomarker for prognosis of OSCC patients.

Regulation of proliferation and cell cycle by protein regulator of cytokinesis 1 in oral squamous cell carcinoma

Protein regulator of cytokinesis 1 (PRC1), a microtubule-associated protein, has emerged as a critical regulator of proliferation and apoptosis, acting predominantly in numerous tumors. However, its function in oral squamous cell carcinoma (OSCC) is still unknown. To establish the roles of PRC1 in OSCC, 95 oral clinical samples (54 OSCC, 24 oral leukoplakia [OLK], and 17 normal oral mucosa) and seven oral cell lines (6 OSCC and 1 normal oral cell lines) were analyzed using a series of molecular and genomic assays both in vivo and in vitro were conducted in this study. Herein, we provide evidence demonstrating that expression of PRC1 closely correlates with the degree of epithelial dysplasia in OLK (n = 24) (p < 0.001), and the poor differentiation, large tumor volume, lymph node metastasis, and high-clinical stage in OSCC (n = 54) (p < 0.05), illustrating that PRC1 has a promotive influence on tumor progression in OSCC. Simultaneously, we observed that PRC1 knockdown in OSCC cell lines caused G2/M phase arrest (p < 0.05), inhibited cell proliferation in vitro (p < 0.05) and tumor growth in vivo (p < 0.001). Furthermore, the effects of PRC1 on the regulation of proliferation and cell cycle transition in OSCC samples were mediated by p53. The p53/PRC1/EGFR signaling pathway was found to be implicated in the tumor progression of OSCC. Based on our data, we demonstrate that PRC1 is a key factor in regulating proliferation and the cell cycle, pointing to the potential benefits of PRC1-targeted therapies for OSCC.

Plasma lipid profiling and diagnostic biomarkers for oral squamous cell carcinoma

Biological requirements for tumor cell proliferation include the sustained increase of structural, energetic, signal transduction and biosynthetic precursors. Because lipids participate in membrane construction, energy storage, and cell signaling. We hypothesized that the differences in lipids between malignant carcinoma and normal controls could be reflected in the bio-fluids. A total of 100 pre-operative plasma samples were collected from 50 oral squamous cell carcinoma (OSCC), 50 normal patients and characterize by lipid profiling using ultra performance liquid chromatography/electro spray ionization mass spectrometry (UPLC-MS). The lipid profiles of the OSCC and control samples as well as the different stages were compared. Differentially expressed lipids were categorized as glycerophospholipids and sphingolipids. All glycerophospholipids were decreased, especially phosphatidylcholine and phosphoethanolamine plasmalogens, whereas sphingolipids were increased in the OSCC patients compared to the controls. We further identified 12 staging related lipids, which could be utilized to discriminate early stage patients from advanced stage patients. In the future, the differential lipids may provide biologists with additional information regarding lipid metabolism and guide clinicians in making individualized therapeutic decisions if these results are confirmed in a larger study.

Electronic Cigarette: Role in the Primary Prevention of Oral Cavity Cancer

BACKGROUND

Cigarette smoke has been identified as the main cause of oral cavity carcinoma. Recently, the electronic cigarette, a battery-operated device, was developed to help smokers stop their tobacco addiction. This study aimed to evaluate the safety of electronic cigarettes and to establish the possible role of such device in the primary prevention of oral cavity cancer.

SUBJECTS AND METHODS

This study included 65 subjects who were divided into three groups (smokers, e-cigarette smokers, and nonsmokers). All subjects were submitted to cytologic examination by scraping of oral mucosa. The slides were microscopically evaluated through a micronucleus assay test.

RESULTS

The prevalence of micronuclei was significantly decreased in the e-cigarette smoker group. There were no statistically significant differences in micronuclei distribution according to the type of cigarette, gender, and age.

CONCLUSIONS

The use of electronic cigarettes seems to be safe for oral cells and should be suggested as an aid to smoking cessation.

An adaptive immune response driven by mature, antigen-experienced T and B cells within the microenvironment of oral squamous cell carcinoma

Lymphocyte infiltrates have been observed in the microenvironment of oral cancer; however, little is known about whether the immune response of the lymphocyte infiltrate affects tumor biology. For a deeper understanding of the role of the infiltrating-lymphocytes in oral squamous cell carcinoma (OSCC), we characterized the lymphocyte infiltrate repertoires and defined their features. Immunohistochemistry revealed considerable T and B cell infiltrates and lymphoid follicles with germinal center-like structures within the tumor microenvironment. Flow cytometry demonstrated that populations of antigen-experienced CD4+ and CD8+ cells were present, as well as an enrichment of regulatory T cells; and T cells expressing programmed death-1 (PD-1) and T cell Ig and mucin protein-3 (Tim-3), indicative of exhaustion, within the tumor microenvironment. Characterization of tumor-infiltrating B cells revealed clear evidence of antigen exposure, in that the cardinal features of an antigen-driven B cell response were present, including somatic mutation, clonal expansion, intraclonal variation and isotype switching. Collectively, our results point to an adaptive immune response occurring within the OSCC microenvironment, which may be sustained by the expression of specific antigens in the tumor.

Investigation of the interplay between plasma lipids and macrophage polarization in small oral squamous cell carcinomas with different outcome: A pilot study of 17 cases

INTRODUCTION

Growing evidence suggests a correlation of alternative polarization of macrophages (M2) with a bad outcome of oral cancer. Macrophage polarization plays a significant role in the progression of hyperlipidemia and atherosclerosis, being influenced from plasma cholesterol. On the other hand plasma lipids have been studied epidemiologically as risk factors in carcinogenesis. Goal of our pilot study was the investigation of a possible association of plasma lipids with tumor outcome through their potential influence on macrophage polarization.

MATERIALS AND METHODS

17 patients with small pN0 OSCC with different clinical outcome, treated operatively without postoperative R(C)T constituted our patient collective. Plasma lipids (total cholesterol and triglycerides) were studied in relation to macrophage polarization (determined through the expression of CD68, CD11c, CD163 and MRC1 antibodies) and tumor outcome.

RESULTS

Patients with pathological chronic course of either plasma cholesterol or triglycerides demonstrated an increased infiltration with alternatively polarized macrophages in their specimens. Patients with pathological chronic course of plasma cholesterol showed moreover a bad tumor outcome.

CONCLUSION

A role of plasma lipids in the tumor outcome via alternative macrophage polarization could be assumed. A larger prospective study is needed to confirm our preliminary results.

Genomic DNA Copy Number Aberrations, Histological Diagnosis, Oral Subsite and Aneuploidy in OPMDs/OSCCs

Oral potentially malignant disorders (OPMDs) characterized by the presence of dysplasia and DNA copy number aberrations (CNAs), may reflect chromosomal instability (CIN) and predispose to oral squamous cell carcinoma (OSCC). Early detection of OPMDs with such characteristics may play a crucial role in OSCC prevention. The aim of this study was to explore the relationship between CNAs, histological diagnosis, oral subsite and aneuploidy in OPMDs/OSCCs. Samples from OPMDs and OSCCs were processed by high-resolution DNA flow cytometry (hr DNA-FCM) to determine the relative nuclear DNA content. Additionally, CNAs were obtained for a subset of these samples by genome-wide array comparative genomic hybridization (aCGH) using DNA extracted from either diploid or aneuploid nuclei suspension sorted by FCM. Our study shows that: i) aneuploidy, global genomic imbalance (measured as the total number of CNAs) and specific focal CNAs occur early in the development of oral cancer and become more frequent at later stages; ii) OPMDs limited to tongue (TNG) mucosa display a higher frequency of aneuploidy compared to OPMDs confined to buccal mucosa (BM) as measured by DNA-FCM; iii) TNG OPMDs/OSCCs show peculiar features of CIN compared to BM OPMDs/OSCCs given the preferential association with total broad and specific focal CNA gains. Follow-up studies are warranted to establish whether the presence of DNA aneuploidy and specific focal or broad CNAs may predict cancer development in non-dysplastic OPMDs.