Molecular pathogenesis of oral squamous carcinoma

miR-617 interacts with the promoter of DDX27 and positively regulates its expression: implications for cancer therapeutics

Background

Pervasive transcription of the eukaryotic genome generates noncoding RNAs (ncRNAs), which regulate messenger RNA (mRNA) stability and translation. MicroRNAs (miRNAs/miRs) represent a group of well-studied ncRNAs that maintain cellular homeostasis. Thus, any aberration in miRNA expression can cause diseases, including carcinogenesis. According to microRNA microarray analyses, intronic miR-617 is significantly downregulated in oral squamous cell carcinoma (OSCC) tissues compared to normal oral tissues.

Methods

The miR-617-mediated regulation of DDX27 is established by performing experiments on OSCC cell lines, patient samples, and xenograft nude mice model. Overexpression plasmid constructs, bisulphite sequencing PCR, bioinformatics analyses, RT-qPCR, Western blotting, dual-luciferase reporter assay, and cell-based assays are utilized to delineate the role of miR-617 in OSCC.

Results

The present study shows that miR-617 has an anti-proliferative role in OSCC cells and is partly downregulated in OSCC cells due to the hypermethylation of its independent promoter. Further, we demonstrate that miR-617 upregulates DDX27 gene by interacting with its promoter in a dose-dependent and sequence-specific manner, and this interaction is found to be biologically relevant in OSCC patient samples. Subsequently, we show that miR-617 regulates cell proliferation, apoptosis, and anchorage-independent growth of OSCC cells by modulating DDX27 levels. Besides, our study shows that miR-617 exerts its effects through the PI3K/AKT/MTOR pathway via regulating DDX27 levels. Furthermore, the OSCC xenograft study in nude mice shows the anti-tumorigenic potential of miR-617.

Conclusion

miR-617-mediated upregulation of DDX27 is a novel mechanism in OSCC and underscores the therapeutic potential of synthetic miR-617 mimics in cancer therapeutics. To the best of our knowledge, miR-617 is the 15th example of a miRNA that upregulates the expression of a protein-coding gene by interacting with its promoter.

Targeting Oral Cancer: In Silico Docking Studies of Phytochemicals on Oncogenic Molecular Markers

OBJECTIVE

Molecular docking is a key tool in structural molecular biology and computer-assisted drug design. Oral carcinogenesis is a complex, multistep process in which genetic events within signal transduction pathways governing normal cellular physiology are quantitatively or qualitatively altered. There are various molecular targets like Cyclin D and PI3k- alpha Ras Binding Domain receptor protein involved in the pathogenesis of Oral Squamous Cell Carcinoma. The aim of the study is to demonstrate the computer aided drug design to identify a potent natural molecule for targeting cyclin D4 and PI3K RAS binding protein.

MATERIALS AND METHODS

Target selection (Cyclin D1 and PI3K-alpha Ras Binding Domain receptor) was done and structures were derived from protein data bank. Ligands (Apigenin, Chrysoeriol and Luteolin) selection was done and structure derived. Final docking was performed by Autodock.

RESULTS

From the docking results it can be seen that luteolin has the highest binding energy (-5.45) with the Cyclin D receptor molecule followed by Chrysoeriol (-4.99) and Apigenin (-4.96). The binding energies of the ligands against PI3K-alpha Ras Binding Domain receptors were Apigenin (-4.51), Chrysoeriol (-4.6) and Luteolin (-4.56).

CONCLUSION

The study concludes that all the three selected ligands possess high binding energy with both the target proteins involved in carcinogenesis with highest binding energy possessed by Luteolin against the Cyclin D receptor and by Chrysoeriol against PI3K-RAS binding protein. Thus their activity can be utilized to derive potential Anti-cancer therapeutic drugs.

Expression of caveolin 1 in oral squamous cell carcinoma

Context

Caveolin-1 is a surface protein that is a major structural component of caveolae, which are vesicles of the plasma membrane integral to a variety of signal transduction molecules and transport functions. Caveolin-1 is a biomarker undergoing research & studies have shown an increased expression of Cav-1 in the stepwise carcinogenesis from the normal oral mucosa, hyperplastic mucosa, dysplastic mucosa, precancerous lesions to Oral Squamous Cell Carcinoma. In the present study Correlation between Caveolin-1 expression and grade of tumor was established statistically.

Aims

To study immunohistochemical expression of Caveolin-1 in Oral Squamous Cell Carcinoma.

Settings and Design

Cross sectional study carried out in a tertiary care hospital.

Materials and Methods

A total of 90 cases of histopathologically diagnosed oral squamous cell carcinoma was evaluated. Grading of the cases into well, moderate and poorly differentiated carcinomas was done as per WHO guidelines . Margin and lymph node status were evaluated. Anti- Caveolin-1 antibody (E249)- Caveolae marker ab32577 was used in the dilution of 1:100. Results were expressed taking reference of the methodology used by Hung et al 2003.

Statistical Analysis Used

Statistical Package for the Social Sciences (SPSS 25.0).

Results

Correlation of tumor grade and lymph node metastasis was statistically significant p=0.0006. There was a significant statistical correlation between tumor grade and immunohistochemical expression of Caveolin-1, p- value=0.00. Correlation between Lymph node metastasis and Caveolin-1 was statistically significant, p-value=0.008.

Conclusions

Caveolin-1 expression correlates with aggressive tumor behavior and poor prognostic outcome.

The immunomodulatory impact of naturally derived neem leaf glycoprotein on the initiation progression model of 4NQO induced murine oral carcinogenesis: a preclinical study

Introduction

Murine tumor growth restriction by neem leaf glycoprotein (NLGP) was established in various transplanted models of murine sarcoma, melanoma and carcinoma. However, the role of NLGP in the sequential carcinogenic steps has not been explored. Thus, tongue carcinogenesis in Swiss mice was induced by 4-nitroquinoline-1-oxide (4NQO), which has close resemblance to human carcinogenesis process. Interventional role of NLGP in initiation-promotion protocol established during 4NQO mediated tongue carcinogenesis in relation to systemic immune alteration and epithelial-mesenchymal transition (EMT) is investigated.

Methods

4NQO was painted on tongue of Swiss mice every third day at a dose of 25µl of 5mg/ml stock solution. After five consecutive treatment with 4NQO (starting Day7), one group of mice was treated with NLGP (s.c., 25µg/mice/week), keeping a group as PBS control. Mice were sacrificed in different time-intervals to harvest tongues and studied using histology, immunohistochemistry, flow-cytometry and RT-PCR on different immune cells and EMT markers (e-cadherin, vimentin) to elucidate their phenotypic and secretory status.

Results

Local administration of 4NQO for consecutive 300 days promotes significant alteration in tongue mucosa including erosion in papillae and migration of malignant epithelial cells to the underlying connective tissue stroma with the formation of cell nests (exophytic-hyperkeratosis with mild dysplasia). Therapeutic NLGP treatment delayed pre-neoplastic changes promoting normalization of mucosa by maintaining normal structure. Flow-cytometric evidences suggest that NLGP treatment upregulated CD8+, IFNγ+, granzyme B+, CD11c+ cells in comparison to 4NQO treated mice with a decrease in Ki67+ and CD4+FoxP3+ cells in NLGP treated cohort. RT-PCR demonstrated a marked reduction of MMP9, IL-6, IL-2, CD31 and an upregulation in CCR5 in tongues from 4NQO+NLGP treated mice in comparison to 4NQO treated group. Moreover, 4NQO mediated changes were associated with reduction of e-cadherin and simultaneous up-regulation of vimentin expression in epithelium that was partially reversed by NLGP.

Discussion

Efficacy of NLGP was tested first time in sequential carcinogenesis model and proved effective in delaying the initial progression. NLGP normalizes type 1 immunity including activation of the CD8+T effector functions, reduction of regulatory T cell functions, along with changes in EMT to make the host systemically alert to combat the carcinogenic threat.

The Therapeutic Effects of Mesenchymal Stem Cells and their Secretome on Oral Squamous Cell Carcinoma

Oral cancers are prevalent in the human population, particularly in unindustrialized countries. In 90 % of oral cancers, the tumors arise from squamous cells, which is called oral squamous cell carcinoma (OSCC). Despite new treatment strategies, the morbidity and mortality rates are still high. Current treatment options including surgery, chemotherapy, and radiotherapy are not effective in the treatment of the tumor. Cell therapy with mesenchymal stem cells (MSCs) is considered one of the leading strategies in cancer treatment. However, the field of MSC therapy in OSCC is immature and ongoing studies are being conducted in experimental and pre-clinical studies. Here, we reviewed these studies to figure out whether the use of MSCs could be worthwhile in OSCC therapy or not. Both native and engineered MSCs as well as their secretome have been used in the treatment of OSCC. It seems that genetically modified MSCs or their secretome could inhibit the tumorigenesis of OSCC. However, further pre-clinical studies are required to come to a conclusion.

The emerging role of oral microbiota in oral cancer initiation, progression and stemness

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy among the Head and Neck cancer. OSCCs are highly inflammatory, immune-suppressive, and aggressive tumors. Recent sequencing based studies demonstrated the involvement of different oral microbiota in oral cavity diseases leading OSCC carcinogenesis, initiation and progression. Researches showed that oral microbiota can activate different inflammatory pathways and cancer stem cells (CSCs) associated stemness pathways for tumor progression. We speculate that CSCs and their niche cells may interact with the microbiotas to promote tumor progression and stemness. Certain oral microbiotas are reported to be involved in dysbiosis, pre-cancerous lesions, and OSCC development. Identification of these specific microbiota including Human papillomavirus (HPV), Porphyromonas gingivalis (PG), and Fusobacterium nucleatum (FN) provides us with a new opportunity to study the bacteria/stem cell, as well as bacteria/OSCC cells interaction that promote OSCC initiation, progression and stemness. Importantly, these evidences enabled us to develop in-vitro and in-vivo models to study microbiota interaction with stem cell niche defense as well as CSC niche defense. Thus in this review, the role of oral microbiota in OSCC has been explored with a special focus on how oral microbiota induces OSCC initiation and stemness by modulating the oral mucosal stem cell and CSC niche defense.

Overexpression of deubiquitinase (usp 36) in oral squamous cell carcinoma

Aim

Oral cancer is one of the top three types of cancer and is of significant public health importance in India. A common post-translational modification in cells is ubiquitination/deubiquitination, and its dysregulation is closely associated with the development of cancer. Studies on the role of ubiquitination in oral squamous cell carcinoma (OSCC) are lacking. Increased expression of usp36 has been observed in various types of cancer, and this study aimed to check the gene expression of usp36 in OSCC patients. In this study, we analyzed the expression of ubiquitin-specific proteases (USPs) 36 in OSCC.

Materials and Methods

A total of 15 OSCC patients at different stages of tumor differentiation and age- and sex-matched controls were recruited for the study. The patients were categorized based on their differentiation patterns. RNA was extracted from the tissues, and usp36 gene expression was checked in these samples using a quantitative real-time PCR technique.

Results

Our study showed increased expression of usp36 gene in OSCC patients. The usp36 mRNA was 231.8 ± 137.94 folds higher in well-differentiated squamous cell carcinoma patients, 38.18 ± 3.77 folds higher in moderately differentiated squamous cell carcinoma patients, and 25.49 ± 7.30 folds higher in poorly differentiated squamous cell carcinoma patients compared to control tissues.

Conclusion

Our study reports, for the first time, an increased gene expression of usp36 in OSCC tissues.

Effect of Harvey Rat Sarcoma Virus Mutation in Oral Squamous Cell Carcinoma and Its Influence on Different Populations: A Systematic Review

The information for protein synthesis is given by the genes. These proteins are responsible for controlling functions like cell growth, differentiation, cell maturation, and cell death. In the case of genetic mutations, the protein functions get disturbed leading to a drastic shift in the normal physiological functions of cell growth, differentiation, and proliferation, making the normal cell cancerous. The Harvey rat sarcoma virus (HRAS) gene is an oncogene that belongs to the rat sarcoma virus (RAS) family. HRAS gene provides the instructions for making the HRAS protein that plays an important role in regulating cell division and when the HRAS gene gets mutated it gets involved in initiating cancer. HRAS mutation has been frequently noted in head and neck cancers; however, the mechanism of HRAS mutation involved in the initiation of oral squamous cell carcinoma (OSCC) still remains unexplored. An elaborate systematic literature search was done in PubMed, Scopus, and Web of Science databases. It was found that the Ras-dependent mutations affect the involved upstream and downstream components of the Ras-Raf-MAPK (rat sarcoma virus-rapidly accelerated fibrosarcoma-mitogen-activated protein kinase) pathway deregulating the signal leading to tumorigenesis. The Ras mutation can affect the Ras-Raf-MAPK pathway at different stages. The disease caused is based on the frequency of the HRAS mutation and it can lead to diverse cellular outcomes as it is mainly associated with cell division, differentiation, growth, survival, and the cell cycle. The crosstalk between the signaling pathways is controlled by the signaling molecules resulting in the creation of molecular networks. The balance of these molecular networks is very important to determine the cellular outcome. This systematic review inspects the molecular network of HRAS and its vital role in carcinogenesis. It is aimed at exploring and summarizing the contributions of the HRAS mutation involved in the pathogenesis of OSCC.

Conceptual model for progression of oral cancer - our perspective

Oral cancer was and still is an underestimated disease in terms of incidence and mortality rates. As a result, requires early detection and urgent prevention. This article describes a framework that covers the significant stages of conceptual development of oral cancer. Conceptual model is useful in understanding the pathogenesis and understand the disease processes. This article signifies information on various aspects of perspective risk and the role played by it. Article covers the following aspects: what are the perspective risks, what changes it causes to normal cell, what are the direct and indirect effects on normal cell, cellular changes seen with normal cell when affected with perspective risk, transformation of normal cell to oral potentially malignant disorders (OPMD) and changes seen during transformation into cancer. Understanding the conceptual model of oral cancer transformation will be a paradigm shift in future research in the field and early management of oral cancer, which will reduce the disease burden on the nation.

Assessment of Therapeutic Bio-Activity of Cinnamoyl Sulfonamide Hydroxamate in Squamous Cell Carcinoma

Background Cancer is the second most common cause of death. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Many treatment modalities such as chemotherapy, radiotherapy, surgery, and immunotherapy are emerging but still, the patients' quality of life is questionable. Despite the advances in therapeutic approaches, the percentages of morbidity and mortality of OSCC have not improved significantly during the last 30 years. Treatment using natural products can act as a potent anti-cancer agent with reduced adverse effects. Cinnamic acid derivatives exhibit anti-cancer potential through histone deacetylase inhibitor (HDAC) enzyme inhibition. Methodology In an experimental study design, cinnamoyl hydroxamate derivatives were prepared. The structure was confirmed using ultraviolet-visible spectroscopy (UV-Vis), nuclear magnetic resonance (NMR), infrared spectroscopy, and mass spectrophotometry. An in-vitro antioxidant assay using nitric oxide scavenging and reducing power assay was done and an in-vitro cytotoxic (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay and viability assay were carried out using tryphan blue dye. Results Statistical analysis was performed using SPSS (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp). Cinnamoyl hydroxamate derivatives were obtained and named as compounds 3a (E)-N-Hydroxy-3-(4-(N-(phenyl bromo) sulfamoyl) phenyl) acrylamide-) and 3b ((E)-N-Hydroxy-3-(4-(N-(phenyl nitro) sulfamoyl) phenyl) acrylamide). In the nitric oxide scavenging assay, compound 3a showed good antioxidant activity than 3b. Reducing power assay was higher in 3a compared to 3b. Cell viability using tryphan blue exhibited a concentration decrease in % cell viability with an increase in the concentration of human oral cavity squamous cell carcinoma cell line (OECM 1), a unique head and neck squamous carcinoma cell line (UM SCC 6) & human oral squamous cell carcinoma forming metastatic foci (HSC 3) cell lines. Conclusion The results of the present study revealed that the study compounds play a vital role in the up-regulation of apoptotic pathways and regulation of terminal differentiation pathways. The compounds showed good anti-oxidant and anti-cancer activities in lesser concentrations, hence they can be used as a therapeutic agent for oral squamous cell carcinoma.

Mechanisms of hedgehog, calcium and retinoic acid signalling pathway inhibitors: Plausible modes of action along the MLL-EZH2-p53 axis in cellular growth control

Understanding the molecular mechanism(s) of small compounds in cellular growth control are essential for using those against the disease(s). Oral cancers exhibit a very high mortality rate due to higher metastatic potential. Aberrant EGFR, RAR, HH signalling, enhanced [Ca²⁺] and oxidative stress are some of the important characteristics of oral cancer. So, we target these for our study. Herein, we tested the effect of fendiline hydrochloride (FH) as an LTCC Ca²⁺-channel inhibitor, erismodegib (a SMO inhibitor of HH-signalling) and all-trans retinoic acid (RA) inducer of RAR signalling that causes cellular differentiation. OCT4 activating compound (OAC1) counters differentiation and induces stemness properties. Cytosine β-D arabinofuranoside (Cyto-BDA), a DNA replication inhibitor was used to reduce high proliferative capacity. Treatment of FaDu cells with OAC1, Cyto-BDA and FH increase G0/G1 population by 3%, 20% and 7% respectively, and lead to reduction of cyclin D1, CDK4/6 levels. Erismodegib arrests the cells in S-phase with reduced cyclin-E1&A1 levels, whereas RA-treatment causes G2/M phase arrest with reduced cyclin-B1. There was a decrease in the expression of EGFR and mesenchymal markers, Snail/Slug/Vim/Zeb/Twist, and increased E-cadherin expression in all the drug treatments, indicating a reduction in proliferative signal and EMT. Enhanced MLL2 (Mll4) and reduced EZH2 expression associated overexpression of p53 and p21 were traced out. We conclude that these drugs impact expression of epigenetic modifiers by modulating signalling pathways and the epigenetic modifiers then controls the expression of cell cycle control genes, including p53 and p21.

Noncoding RNAs in oral cancer

Oral cancer (OC) is the most prevalent subtype of cancer arising in the head and neck region. OC risk is mainly attributed to behavioral risk factors such as exposure to tobacco and excessive alcohol consumption, and a lesser extent to viral infections such as human papillomaviruses and Epstein-Barr viruses. In addition to these acquired risk factors, heritable genetic factors have shown to be associated with OC risk. Despite the high incidence, biomarkers for OC diagnosis are lacking and consequently, patients are often diagnosed in advanced stages. This delay in diagnosis is reflected by poor overall outcomes of OC patients, where 5-year overall survival is around 50%. Among the biomarkers proposed for cancer detection, noncoding RNA (ncRNA) can be considered as one of the most promising categories of biomarkers due to their role in virtually all cellular processes. Similar to other cancer types, changes in expressions of ncRNAs have been reported in OC and a number of ncRNAs have diagnostic, prognostic, and therapeutic potential. Moreover, some ncRNAs are capable of regulating gene expression by various mechanisms. Therefore, elucidating the current literature on the four main types of ncRNAs namely, microRNA, lncRNA, snoRNA, piwi-RNA, and circular RNA in the context of OC pathogenesis is timely and would enable further improvements and innovations in diagnosis, prognosis, and treatment of OC. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

Stonin 2 activates lysosomal-mTOR axis for cell survival in oral cancer

Aberrant expression of various genes is associated with the progression of oral squamous cell carcinoma. Stonin 2, an endocytic protein, has a prominent role in clathrin-associated endocytosis. Its position in oral cancer is still unknown. Here, we report that STON2 expression increases with an increase in the grade of the oral cancer tissue. Further, STON2 overexpressed cells possess a higher rate of proliferation and migraton in oral cancer cells. STON2 helps maintain lysosomal functions by preserving the lysosomal membrane integrity. It activates the Akt-mTOR axis and retains the mTOR on the membrane of the lysosomes. Further, we have identified an inhibitor of STON2, i.e., Trifluoperazine dihydrochloride (TFP), which targets the lysosomal axis by disrupting the Akt-mTOR pathway and causes lysosomal membrane permeabilization. Intererstingly, TFP shows a decrease in cell vaibility on the oral cancer cells and it was observed that cell viability is restored in TFP-treated STON2 overexpressed cells. Moreover, the lysosomal activity and the Akt-mTOR expression are restored in STON2 overexpressed cells co-treated with TFP, establishing TFP targets STON2 to showcase its anti-cancer effects in oral cancer. In conclusion, STON2 might serve as a potential biomarker in oral cancer, and its inhibition could functions as a novel anti-cancer mechanims against oral cancer.

Role of E2F transcription factor in Oral cancer: Recent Insight and Advancements

The family of mammalian E2F transcription factors (E2Fs) comprise of 8 members (E2F1-E2F8) classified as activators (E2F1-E2F3) and repressors (E2F4-E2F8) primarily regulating the expression of several genes related to cell proliferation, apoptosis and differentiation, mainly in a cell cycle-dependent manner. E2F activity is frequently controlled via the retinoblastoma protein (pRb), cyclins, p53 and the ubiquitin-proteasome pathway. Additionally, genetic or epigenetic changes result in the deregulation of E2F family genes expression altering S phase entry and apoptosis, an important hallmark for the onset and development of cancer. Although studies reveal E2Fs to be involved in several human malignancies, the mechanisms underlying the role of E2Fs in oral cancer lies nascent and needs further investigations. This review focuses on the role of E2Fs in oral cancer and the etiological factors regulating E2Fs activity, which in turn transcriptionally control the expression of their target genes, thus contributing to cell proliferation, metastasis, and drug/therapy resistance. Further, we will discuss therapeutic strategies for E2Fs, which may prevent oral tumor growth, metastasis, and drug resistance.

Oxidative Status Determines the Cytotoxicity of Ascorbic Acid in Human Oral Normal and Cancer Cells

Oral squamous cell carcinoma (OSCC) can arise anywhere in the oral cavity. OSCC's molecular pathogenesis is complex, resulting from a wide range of events that involve the interplay between genetic mutations and altered levels of transcripts, proteins, and metabolites. Platinum-based drugs are the first-line treatment for OSCC; however, severe side-effects and resistance are challenging issues. Thus, there is an urgent clinical need to develop novel and/or combinatory therapeutics. In this study, we investigated the cytotoxic effects of pharmacological concentrations of ascorbate on two human oral cell lines, the oral epidermoid carcinoma meng-1 (OECM-1) cell and the Smulow-Glickman (SG) human normal gingival epithelial cell. Our study examined the potential functional impact of pharmacological concentrations of ascorbates on the cell-cycle profiles, mitochondrial-membrane potential, oxidative response, the synergistic effect of cisplatin, and the differential responsiveness between OECM-1 and SG cells. Two forms of ascorbate, free and sodium forms, were applied to examine the cytotoxic effect and it was found that both forms had a similar higher sensitivity to OECM-1 cells than to SG cells. In addition, our study data suggest that the determinant factor of cell density is important for ascorbate-induced cytotoxicity in OECM-1 and SG cells. Our findings further revealed that the cytotoxic effect might be mediated through the induction of mitochondrial reactive oxygen species (ROS) generation and the reduction in cytosolic ROS generation. The combination index supported the agonistic effect between sodium ascorbate and cisplatin in OECM-1 cells, but not in SG cells. In summary, our current findings provide supporting evidence for ascorbate to serve as a sensitizer for platinum-based treatment of OSCC. Hence, our work provides not only repurposing of the drug, ascorbate, but also an opportunity to decrease the side-effects of, and risk of resistance to, platinum-based treatment for OSCC.

Novel Strategies for the Bioavailability Augmentation and Efficacy Improvement of Natural Products in Oral Cancer

Oral cancer is emerging as a major cause of mortality globally. Oral cancer occupies a significant proportion of the head and neck, including the cheeks, tongue, and oral cavity. Conventional methods in the treatment of cancer involve surgery, radiotherapy, and immunotherapy, and these have not proven to completely eradicate cancerous cells, may lead to the reoccurrence of oral cancer, and possess numerous adverse side effects. Advancements in novel drug delivery approaches have gained popularity in cancer management with an increase in the number of cases associated with oral cancer. Natural products are potent sources for drug discovery, especially for anticancer drugs. Natural product delivery has major challenges due to its low solubility, poor absorption, inappropriate size, instability, poor permeation, and first-pass metabolism. Therefore, it is of prime importance to investigate novel treatment approaches for the delivery of bioactive natural products. Nanotechnology is an advanced method of delivering cancer therapy with minimal damage to normal cells while targeting cancer cells. Therefore, the present review elaborates on the advancements in novel strategies for natural product delivery that lead to the significant enhancement of bioavailability, in vivo activity, and fewer adverse events for the prevention and treatment of oral cancer. Various approaches to accomplish the desired results involve size reduction, surface property modification, and polymer attachment, which collectively result in the higher stability of the formulation.

Quantitative Proteomic Analysis of Non-Tobacco Associated Oral Squamous Cell Carcinoma Reveals Deregulation of Cytoskeletal and Apoptotic Proteins

BACKGROUND

The exact etiology of non-tobacco associated oral squamous cell carcinoma (NT-OSCC) is still unknown. The lack of established biomarkers for oral NT-OSCC has resulted in less effective management and poor prognosis. Here, we report for the first time a panel of potential markers identified from the quantitative proteomic analysis of NT-OSCC using two-dimensional gel-electrophoresis (2D-GE) using matrix-assisted laser desorption/ionization - time of flight (MALDI-TOF) coupled with mass spectrometry (MS) and further analysis using protein analysis through evolutionary relationships (PANTHER) database.

OBJECTIVE

To quantitatively analyze the proteomic profile of non-tobacco associated oral squamous cell carcinoma.

METHODS

Twenty fresh tissue samples were collected from healthy controls and NT-OSCC, ten each, and were subjected to proteomic analysis. Sample quantification for the presence of protein was done using Bradford assay and bovine serum albumin was used as a standard protein to obtain the standard graph. Fractionation of protein was done using sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE) and they were separated based on their molecular weight. MS analysis was done and the purified peptides were analysed using MALDI-TOF. PANTHER database for functional classification and pathway analysis was done for identification of protein expression.

RESULTS

Our approach of combining 2D-GE with MS identified four candidate proteins including keratin, alpha-1-antitrypsin (AAT), S100 and serpin B5 with significant differential expression in NT-OSCC as compared with healthy controls. The results showed that the levels of these proteins were significantly upregulated in NT-OSCC when compared to the healthy controls that suggests that these proteins can be used as candidate targets for NT-OSCC therapeutics.

CONCLUSION

The differentially expressed proteins are found to be involved in apoptotic signalling pathways, cytoskeletal dynamics and are known to play a critical role in oral tumorigenesis. Put together, the results provide available baseline information for understanding the development and progression of NT-OSCC. These identified proteins on further validation may be used as potential biomarkers in future for early detection and predicting therapeutic outcome of patients with NT-OSCC.

New Insights on Acanthus ebracteatus Vahl: UPLC-ESI-QTOF-MS Profile, Antioxidant, Antimicrobial and Anticancer Activities

This study investigated the antioxidant, antimicrobial, anticancer, and phytochemical profiling of extracts from the leaves and stem/root of Acanthus ebracteatus (AE). The total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical-scavenging activity, 2, 2′-azino-Bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging activity, metal chelating activities (MCA), ferric reducing antioxidant power (FRAP) and oxygen radical antioxidant capacity (ORAC) were used for antioxidant assessment. The ethanolic extracts of the leaves (AEL-nor) and stem/root (AEWP-nor) without chlorophyll removal and those with chlorophyll removal, using sedimentation process (AEL-sed and AEWP-sed), were prepared. Generally, AEL-sed showed the highest antioxidant activity (FRAP: 1113.2 µmol TE/g; ORAC: 11.52 µmol TE/g; MCA: 47.83 µmol EDTA/g; ABTS 67.73 µmol TE/g; DPPH 498.8 µmol TE/g; TPC: 140.50 mg/GAE g and TFC: 110.40 mg/CE g) compared with other extracts. Likewise, AEL-sed also showed the highest bacteriostatic (MIC) and bactericidal (MBC) effects, as well as the highest anticancer and antiproliferative activity against oral squamous carcinoma (CLS-354/WT) cells. UPLC-ESI-QTOF/MS analysis of AEL-sed and AEWP-sed tentatively identified several bioactive compounds in the extracts, including flavonoids, phenols, iridoids, and nucleosides. Our results provide a potentially valuable application for A. ebracteatus, especially in further exploration of the plant in oxidative stress-related disorders, as well as the application of the plant as potential nutraceuticals and cosmeceuticals.

Targeting Cancer Stem Cell Markers or Pathways: A Potential Therapeutic Strategy for Oral Cancer Treatment

Cancer stem cells (CSCs) are a small subset of cancer cells with stem cell-like properties, self-renewal potential, and differentiation capacity into multiple cell types. Critical genetic alterations or aberrantly activated signaling pathways associated with drug resistance and recurrence have been observed in multiple types of CSCs. In this context, CSCs are considered to be responsible for tumor initiation, growth, progression, therapeutic resistance, and metastasis. Therefore, to effectively eradicate CSCs, tremendous efforts have been devoted to identify specific target molecules that play a critical role in regulating their distinct functions and to develop novel therapeutics, such as proteins, monoclonal antibodies, selective small molecule inhibitors, and small antisense RNA (asRNA) drugs. Similar to other CSC types, oral CSCs can be characterized by certain pluripotency-associated markers, and oral CSCs can also survive and form 3D tumor spheres in suspension culture conditions. These oral CSC-targeting therapeutics selectively suppress specific surface markers or key signaling components and subsequently inhibit the stem-like properties of oral CSCs. A large number of new therapeutic candidates have been tested, and some products are currently in the pre-clinical or clinical development phase. In the present study, we review new oral CSC-targeted therapeutic strategies and discuss the various specific CSC surface markers and key signaling components involved in the stem-like properties, growth, drug resistance, and tumorigenicity of oral CSCs.

Screening of oral squamous cell carcinoma by serum changes: A systematic review and meta-analysis

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the sixth common cancer in the world and 90% of oral malignant tumors. The aim of this study was the investigation of changes in some metabolic elements of OSCC patients' serum.

MATERIALS AND METHODS

In this study, international databases such as PubMed, Science Direct, Scopus, Web of Science, and National (Magiran, IranMedex) were searched from 1980 to 2019. To analyze the data, a random-effects model was used to combine the differences in the mean of studies in STATA Software (version 12).

RESULTS

A total of 724 articles were found with initial searching that 474 duplicate articles, 228 articles were excluded by reviewing the title and abstracts, and 17 articles were excluded from the study due to lack of inclusion criteria. Finally, five articles entered the meta-analysis phase. The mean difference value for zinc concentration of blood serum was 2.01 (95% confidence interval (CI): 0.36-3.66) and for copper was 1.04 (95% CI: 0.01-2.07). In both populations, the heterogeneity was found between studies (I ² = 97.4, P < 0.001).

CONCLUSION

Probably higher serum levels of copper and zinc could be one way to help to do a primary screening of OSCC in suspected patients.

The Role of Periodontopathogens and Oral Microbiome in the Progression of Oral Cancer. A Review

Chronic periodontal disease and oral bacteria dysbiosis can lead to the accumulation of genetic mutations that eventually stimulate Oral Squamous Cell Cancer (OSCC). The annual incidence of OSCC is increasing significantly, and almost half of the cases are diagnosed in an advanced stage. Worldwide there are more than 380,000 new cases diagnosed every year, and a topic of extensive research in the last few years is the alteration of oral bacteria, their compositional changes and microbiome. This review aims to establish the relationship between bacterial dysbiosis and OSCC. Several bacteria implicated in periodontal disease, including Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, and some Streptococcus species, promote angiogenesis, cell proliferation, and alteration in the host defense process; these same bacteria have been present in different stages of OSCC. Our review showed that genes involved in bacterial chemotaxis, the lipopolysaccharide (LPS) of the cell wall membrane of gram negatives bacteria, were significantly increased in patients with OSCC. Additionally, some bacterial diversity, particularly with Firmicutes, and Actinobacteria species, has been identified in pre-cancerous stage samples. This review suggests the importance of an early diagnosis and more comprehensive periodontal therapy for patients by the dental care professional.

SPINK7 expression changes accompanied by HER2, P53 and RB1 can be relevant in predicting oral squamous cell carcinoma at a molecular level

The oral squamous cell carcinoma (OSCC), which has a high morbidity rate, affects patients worldwide. Changes in SPINK7 in precancerous lesions could promote oncogenesis. Our aim was to evaluate SPINK7 as a potential molecular biomarker which predicts OSCC stages, compared to: HER2, TP53, RB1, NFKB and CYP4B1. This study used oral biopsies from three patient groups: dysplasia (n = 33), less invasive (n = 28) and highly invasive OSCC (n = 18). The control group consisted of clinically suspicious cases later to be confirmed as normal mucosa (n = 20). Gene levels of SPINK7, P53, RB, NFKB and CYP4B1 were quantified by qPCR. SPINK7 levels were correlated with a cohort of 330 patients from the TCGA. Also, SPINK7, HER2, TP53, and RB1, were evaluated by immunohistofluorescence. One-way Kruskal–Wallis test and Dunn's post-hoc with a p < 0.05 significance was used to analyze data. In OSCC, the SPINK7 expression had down regulated while P53, RB, NFKB and CYP4B1 had up regulated (p < 0.001). SPINK7 had also diminished in TCGA patients (p = 2.10e-6). In less invasive OSCC, SPINK7 and HER2 proteins had decreased while TP53 and RB1 had increased with respect to the other groups (p < 0.05). The changes of SPINK7 accompanied by HER2, P53 and RB1 can be used to classify the molecular stage of OSCC lesions allowing a diagnosis at molecular and histopathological levels.

Diverse roles of bitter melon (Momordica charantia) in prevention of oral cancer

Oral squamous cell carcinoma (OSCC) is one of the common lethal malignancies which is increasing rapidly in the world. Increasing risks from alcohol and tobacco habits, lack of early detection markers, lack of effective chemotherapeutic agents, recurrence and distant metastasis make the disease more complicated to manage. Laboratory-based studies and epidemiological studies indicate important roles of nutraceuticals to manage different cancers. The plant bitter melon (Momordica charantia) is a good source of nutrients and bio-active phytochemicals such as triterpenoids, triterpene glycosides, phenolic acids, flavonoids, lectins, sterols and proteins. The plant is widely grown in Asia, Africa, and South America. Bitter melon has traditionally been used as a folk medicine and Ayurvedic medicine in Asian culture to treat diseases such as diabetes, since ancient times. The crude extract and some of the isolated pure compounds of bitter melon show potential anticancer effects against different cancers. In this review, we shed light on its effect on OSCC. Bitter melon extract has been found to inhibit cell proliferation and metabolism, induce cell death and enhance the immune defense system in the prevention of OSCC in vitro and in vivo. Thus, bitter melon may be used as an attractive chemopreventive agent in progression towards OSCC clinical study.

MicroRNAs and Long Non-Coding RNAs as Regulators of NANOG Expression in the Development of Oral Squamous Cell Carcinoma

NANOG is a stem cell transcription factor that is believed to play an important role in the development of oral squamous cell carcinoma (OSCC), but there is limited data regarding the role of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the regulation of NANOG expression. We therefore analyzed expression of NANOG, NANOG-regulating miRNAs and lncRNAs in OSCC cancerogenesis, using oral biopsy samples from 66 patients including normal mucosa, dysplasia, and OSCC. Expression analysis of NANOG, miR-34a, miR-145, RoR, SNHG1, AB209630, and TP53 was performed using qPCR and immunohistochemistry for NANOG protein detection. NANOG protein showed no staining in normal mucosa, very weak in low-grade dysplasia, and strong staining in high-grade dysplasia and OSCC. NANOG, miR-145, RoR, and SNHG1 showed up-regulation, TP53 and miR-34a showed down-regulation, and AB209630 showed variable expression during cancerogenesis. NANOG mRNA was up-regulated early in cancerogenesis, before strong protein expression can be detected. NANOG was in correlation with miR-145 and RoR. Our results suggest that miRNAs and lncRNAs, particularly miR-145 and RoR, might be important post-transcription regulatory mechanisms of NANOG in OSCC cancerogenesis. Furthermore, NANOG protein detection has a diagnostic potential for oral high-grade dysplasia, distinguishing it from low-grade dysplasia and non-neoplastic reactive lesions.

Interaction of tobacco chewing and smoking habit with interleukin 6 promoter polymorphism in oral precancerous lesions and oral cancer

OBJECTIVE

Our study aims to determine the influence of smoking or tobacco chewing and the association of Interleukin 6 (IL-6) polymorphism, where G is substituted by A at the position - 596 (IL-6 - 596 G/A) and substitution of G by cytosine (C) at position - 572 (IL-6 - 572 G/C) on the susceptibility of precancerous oral lesions and oral cancer.

MATERIALS AND METHODS

The participants consisted of 250 subjects among which 75 were suffering from oral cancer, 75 subjects with precancerous oral lesions and 100 were healthy controls. Single-nucleotide polymorphism study (SNP) was done by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).

RESULTS

IL-6 - 596 G/A SNP revealed genotypes, GG, and GA in subjects with precancerous oral lesions and oral cancer, and AA genotype was not found in any subject. IL-6 - 596 G/A was strongly associated with oral precancerous lesions but not with oral cancer. The present study reports that smokers carrying GA for IL-6 - 596 G/A were at several folds higher risk of developing oral precancerous lesions. Smokers with GC and CC for IL-6 - 572 G/C were at higher risk of developing oral precancerous lesions. No significant interaction was observed between these habits and IL-6 - 596 G/A and IL-6 - 572 G/C SNP with oral cancer.

CONCLUSION

The interaction of variant A allele of IL-6 - 596 G/A and C allele of IL-6 - 572 G/C polymorphism with smoking and increases the risk of oral precancerous lesions. Tobacco chewing was not related with IL-6 - 596 G/A or IL-6 - 572 G/C in oral precancerous lesions or oral cancer.

CLINICAL RELEVANCE

The study will help to determine the susceptibility of individuals with smoking or chewing habits to the development of oral precancerous lesion and oral cancer by monitoring the IL-6 SNPs which can be used as a biomarker for risk determination.

Features of oral squamous cell carcinoma in ex vivo fluorescence confocal microscopy

BACKGROUND

Real-time microscopic imaging of freshly excised oral squamous cell carcinomas (OSCCs) would be potentially supportive in rapid recognition of oral malignancy and an optimal and time-saving management of patients' surgical treatment.

OBJECTIVES

The aim of this study was to examine oral squamous cell cancer tissue in regards to the commonly known and well-described histomorphologic criteria for the diagnosis of OSCC in ex vivo confocal fluorescent microscopy and to analyze its correlation with grade of differentiation and level of invasiveness.

METHODS

Ex vivo confocal laser scanning microscopy (CLSM) images of 38 OSCCs were evaluated immediately after excision for presence or absence of various cytological and architectural features based on the histopathological background. Next, these features were compared to the grade of differentiation as elaborated via gold standard histologic examination.

RESULTS

Of 38 invasive OSCCs, 14 were well differentiated, while three moderately and 19 were poorly differentiated. The presence of the commonly known cytologic and histopathologic criteria for the diagnosis of oral squamous cell carcinoma such as the destruction of the basal cell membrane, cellular and nuclear pleomorphism, anisocytosis, intraepithelial keratinization, nuclear hyperchromasia, atypical mitotic figures as well as the presence of necrosis, and mixed inflammation could be observed in ex vivo fluorescence confocal microscopy (FCM). In ex vivo fluorescence confocal microscopy pictures, cellular pleomorphism and anisocytosis were observed more often in poorly differentiated OSCCs. Intraepithelial keratinization was associated with well differentiated and moderately differentiated OSCCs.

CONCLUSION

The results demonstrate the high potential of ex vivo fluorescence confocal microscopy in fresh tissue for rapid real-time diagnosis of OSCC.

Metformin inhibits proliferation of oral squamous cell carcinoma cells by suppressing proteolysis of nerve growth factor receptor

OBJECTIVE

We aimed to explore the effects of metformin on oral squamous cell carcinoma (OSCC) cell proliferation and the associated molecular mechanisms.

METHODS

We established an OSCC model in SCC15 cells overexpressing nerve growth factor receptor (NGFR) or the N-terminal region (aa 1-250; NGFR-N), and assessed cell proliferation by CCK-8 assay, colony formation assay, and cell cycle analysis. Levels of NGFR and related genes and proteins were detected by qPCR and western blotting, and NGFR and NGFR-N affinity for p53 was assessed by immunoprecipitation assay. Additionally, the effects of NGFR and NGFR-N on p53 binding with its downstream gene promoters were analyzed by chromatin immunoprecipitation.

RESULTS

Metformin inhibited OSCC cell proliferation and blocked NGFR proteolysis, thereby reducing the generation of its intracellular domain and NGFR-N. Moreover, compared with NGFR, NGFR-N showed higher affinity for p53 and more strongly inactivated p53 to promote cell proliferation. Furthermore, upregulation of NGFR-N downregulated levels of p53-specific downstream transcripts and proteins, whereas these levels were significantly upregulated in metformin-treated cells overexpressing NGFR.

CONCLUSIONS

These results showed that metformin inhibited cell proliferation by suppressing NGFR proteolysis, thereby promoting its antitumor effect in OSCC and offering novel insight into a role for metformin in OSCC treatment.

Cyclin D1 in oral premalignant lesions and oral squamous cell carcinoma: An immunohistochemical study

Background:

Cyclin D1 is derived from PRAD1 or CCND1 gene located on chromosome 11q13 and it acts as a positive regulator of the cell cycle. In normal cells, cyclin D1 promotes progression through the G1 phase of the cell cycle. Over expression of cyclin D1 may lead to shortening of G1 phase, increased cell proliferation and reduced dependency on growth factors. Over expression of cyclin D1 has been reported in various tumors like esophageal carcinoma, hepatocellular carcinoma, lung carcinoma, and head and neck carcinoma.

Aims and Objectives:

The study was carried out to evaluate and compare the expression of Cyclin D1 in premalignant lesion and different grades of oral squamous cell carcinoma.

Materials and Methods:

A total 75 histopathologically diagnosed cases of oral squamous cell carcinoma and oral premalignant lesions cases were evaluated immunohistochemically for cyclin D1 expression.

Results:

We found that cyclin D1 protein expression was significantly altered from epithelial dysplasia to oral squamous cell carcinomas.

Conclusion:

Thus we can conclude that cyclin D1 may be a useful marker in the cases of oral precancer and cancer. It can also act as a potential target for molecular intervention studies in future.

[Research progress on circular RNA in oral squamous cell carcinoma]

Circular RNA, a non-coding RNA that forms a covalently closed continuous loop, exists widely in eukaryotic cells. The biogenesis and biological function of this type of RNA indicate that it can play a crucial role in diseases such as tumors, neural system diseases, and cardiovascular diseases; moreover, this RNA may have great potential use as a biomarker in these diseases. Oral squamous cell carcinoma (OSCC) is a common malignancy in oral surgery that is difficult to cure, metastasizes easily, and has poor prognosis. In this review, we summarize the loop-forming mechanisms and functions of circular RNA and describe the progress of current research in the development of oral cancer.

Hypermethylated PAX1 and ZNF582 genes in the tissue sample are associated with aggressive progression of oral squamous cell carcinoma

BACKGROUND

DNA methylation of paired box gene 1 (PAX1) and zinc finger 582 (ZNF582) is promising cancer biomarkers for oral squamous cell carcinoma detection. This study aims to investigate the correlation between PAX1 or ZNF582 methylation and the progression of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

A total of 135 OSCC cases from Peking University School and Hospital of Stomatology were enrolled in this study. Tissue specimens were collected from the lesion site and corresponding adjacent normal site. The methylation level of these two genes was evaluated in primary and recurrent OSCC group.

RESULTS

Hypermethylation of PAX1 or ZNF582 was observed in lesion sites among primary and recurrent OSCC cases. In the lesion site of primary cases, promoter methylation was observed in T3/T4 (PAX1: P = .02; ZNF582: P = .01), stage III/IV (PAX1: P = .03; ZNF582: P = .01), and bone invasion cases (PAX1: P = .02; ZNF582: P = .047). In the subgroup analysis, the correlation between hypermethylation and OSCC severity remains significant with exposure to smoking/alcohol consumption.

CONCLUSIONS

Hypermethylated PAX1 and ZNF582 can sufficiently act as biomarkers to reflect the severity or progression of OSCC.

Histo-Blood Group Antigens in Oral Cancer and Potentially Malignant Disorders

BACKGROUND

Early detection of oral cancer is of critical importance because survival rates markedly improve when oral lesions are identified at an early stage. Aim of the present study is to investigate the expression of ABO (H) antigens in tissue specimens of oral cancer and potentially malignant disorders and to determine the role of ABO (H) antigens in tumour staging.

MATERIALS AND METHODS

A prospective study was conducted on 60 cases of oral cancer and potentially malignant diseases. Specific red cell adherence test (SRCA-test) was used for studying A, B and O (H) antigens in tissue specimens and iso-antigenicity of epithelium was graded according to degree of adherence of indicator red blood cells.

RESULTS

Among OSMF group, grade II adherence was seen in 53.3% cases, grade III in 33.3% cases, grade IV in 13.3% cases. In leukoplakia group, grade II adherence was seen in 26.7% cases, grade III adherence in 53.3% cases, grade IV adherence in 20% cases. Within the leukoplakia group, cases with dysplasia showed decreased adherence, compared with cases without dysplasia. Oral cancer group, negative adherence was seen in 13.3% cases, grade I adherence in 46.7% cases, grade II in 40% cases. In oral cancer group, antigen reactivity was less in poorly and moderately differentiated carcinoma, compared to well differentiated carcinoma.

CONCLUSIONS

Antigen adherence and degree of loss of ABO (H) antigens in tissue specimens can be used for staging of the tumour.

UBE2C promotes the progression of head and neck squamous cell carcinoma

The development of head and neck squamous cell carcinoma (HNSCC) is a complex pathological process and many cellular and molecular events may occur. The ubiquitin conjugating enzyme E2 (UBE2C) was found to play an oncogenic role in several human cancers. However, its functional role in HNSCC tumorigenesis remains unknown. In this study, UBE2C gene expression in HNSCC was first evaluated using the data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The connection between UBE2C gene expression and patients' survival rates of HNSCC and other human cancers was also investigated. Liquid chromatography with tandem mass spectrometry was used to identify differentially expressed proteins, including UBE2C, between UMSCC1 oral cancer cells and normal human oral keratinocytes (NHOKs). Immunohistochemistry (IHC) was used to verify the differential expression of UBE2C protein between HNSCC and adjacent control tissues. Cell cycle analysis, MTT, colony formation, Transwell migration, and Matrigel invasion assays were used to study the effect of UBE2C downregulation on the malignant phenotypes of HNSCC cells. The bioinformatic analysis of the proteins interacting with UBE2C in HNSCC cells was also performed. Based on the data obtained from the cancer databases and our in vitro studies, we found that UBE2C was overexpressed in HNSCC and patients with high UBE2C expression suffered a remarkably worse overall survival rate than those with low UBE2C expression, and a similar observation was found in a number of other human cancers. UBE2C was also found to be overexpressed in HNSCC cells versus normal human oral keratinocytes and inhibition of UBE2C expression significantly suppressed the malignant phenotypes of HNSCC cells in vitro. The bioinformatic analysis indicated that UBE2C may be involved in head and neck tumorigenesis through the mediation of important pathways such as ubiquitin mediated proteolysis, proteasome, and cell cycle. In conclusion, our results suggest that UBE2C is consistently upregulated in many human solid tumors. It promotes HNSCC progression and may serve as a potential prognostic biomarker in HNSCC. Future studies are warranted to unveil the underlying molecular pathways of UBE2C in HNSCC.

Clinical correlation of opposing molecular signatures in head and neck squamous cell carcinoma

Background

The concept of head and neck cancers (HNSCC) having unique molecular signatures is well accepted but relating this to clinical presentation and disease behaviour is essential for patient benefit. Currently the clinical significance of HNSCC molecular subtypes is uncertain therefore personalisation of HNSCC treatment is not yet possible.

Methods

We performed meta-analysis on 8 microarray studies and identified six significantly up- (PLAU, FN1, CDCA5) and down-regulated (CRNN, CLEC3B and DUOX1) genes which were subsequently quantified by RT-qPCR in 100 HNSCC patient margin and core tumour samples.

Results

Retrospective correlation with sociodemographic and clinicopathological patient details identified two subgroups of opposing molecular signature (+q6 and -q6) that correlated to two recognised high-risk HNSCC populations in the UK. The +q6 group were older, male, and excessive alcohol users whilst the –q6 group were younger, female, paan-chewers and predominantly Bangladeshi. Additionally, all patients with tumour recurrence were in the latter subgroup.

Conclusions

We provide the first evidence linking distinct molecular signatures in HNSCC with clinical presentations. Prospective trials are required to determine the correlation between these distinct genotypes and disease progression or treatment response. This is an important step towards the ultimate goal of improving outcomes by utilising personalised molecular-signature-guided treatments for HNSCC patients.

Interleukin-1beta and Caspase-3 expression serve as independent prognostic markers for metastasis and survival in oral squamous cell carcinoma

BACKGROUND

The Indian subcontinent has the highest incidence and prevalence of oral squamous cell carcinoma (OSCC). Inflammation and apoptosis are two emerging hall marks of cancer that might play a significant role in tumorigenesis and metastasis. Concurrent expression of proinflammatory cytokine (IL-1β) and executioner caspase (Caspase-3) in same OSCC tissue samples has not been reported in an Indian population.

OBJECTIVES

The present study aimed to evaluate the immunohistochemical expression of IL-1β and Caspase-3 in same OSCC tissue samples with clinicopathological correlation and survival analysis in Indian population.

METHODS

A retrospective study was conducted utilizing 40 formalin fixed paraffin embedded histologically diagnosed cases of OSCC comprising of 20 metastatic OSCC and 20 non-metastatic OSCC.

RESULTS

Increased expression of IL-1β and Caspase-3 were observed in metastatic OSCC. Correlation of expression of IL-1β and Caspase-3 with clinicopathological parameters revealed a significant association between these markers and staging, nodal status and site of the lesion.

CONCLUSION

Over expression of IL-1β and Caspase-3 was associated with advanced stage and poor survival of the patient. IL-1β overexpression showed significantly lower disease-free survival and disease specific survival as well. Overexpression of IL-1β and Caspase-3 in incisional OSCC biopsies could be considered for predicting metastasis and survival outcome.

CXCL12 is associated with FoxP3+ tumor-infiltrating lymphocytes and affects the survival of patients with oral squamous cell carcinoma

The role of tumor-infiltrating lymphocytes (TILs) suggests that cancer is a disease with not only a genetic, but also an immunological basis. Additionally, immune cell infiltration is an important feature of oral cancer. C-X-C motif chemokine ligand 12 (CXCL12) serves an important role in immune suppression in the tumor microenvironment. Therefore, the present study investigated how CXCL12 expression in oral squamous cell carcinoma (OSCC) was associated with clinicopathological parameters and TILs distribution. Complete CXCL12, TIL and clinical data were available for 45 patients with oral cancer treated by surgery. Expression levels of CXCL12, CD8⁺ TILs and forkhead box P3 (FoxP3⁺) TILs were assessed by immunohistochemistry in OSCC samples. CXCL12 expression in OSCC cells was observed in 32 (68.9%) cases and was associated with poor differentiation (P=0.045), advanced stages (P<0.001), tumor recurrence (P=0.011), poor overall survival (P=0.0476) and a higher density of FoxP3⁺ TILs (P<0.001). The CD8⁺/FoxP3⁺ ratio was lower in patients with poor differentiation (P=0.034), advanced stage tumors (P=0.015) and tumor recurrence (P=0.002). In addition, the ratio of CD8⁺/FoxP3⁺ TILs was significantly associated with the 5-year overall survival rate (P<0.001). The CD8⁺/FoxP3⁺ ratio was indicated to be a stronger prognostic indicator compared with the density of FoxP3⁺ TILs or CD8⁺ TILs. The present study identified an association between increased CXCL12 expression and FoxP3⁺ cell infiltration in OSCC. Targeting the CXCL12/C-X-C motif chemokine receptor 4 axis in OSCC may be employed as a novel strategy of tumor immunotherapy in the future.

Long non-coding RNA CASC2 serves as a ceRNA of microRNA-21 to promote PDCD4 expression in oral squamous cell carcinoma

Background: Oral squamous cell carcinoma (OSCC) is a common oral disease with high morbidity and mortality. Recently, long non-coding RNAs (lncRNAs) were identified as critical regulators in OSCC tumorigenesis. The present study aimed to work out the functions and the possible molecular mechanisms of lncRNA CASC2 in human OSCC. Methods: The expression levels of CASC2 in clinical OSCC tissue samples and cultured OSCC cell lines were detected by RT-qPCR analysis. MTT assay was performed to detect the proliferation ability of OSCC cells, whereas the apoptosis rate and cell cycle distribution of OSCC cells were determined by flow cytometric analysis. The expression levels of relevant proteins were detected by Western blot assay. Dual-luciferase reporter assay was performed to validate the predicted relationship between CASC2, miR-21 amd PDCD4. The role of CASC2 in OSCC tumorigenesis in vivo was evaluated using a nude mouse tumor model. Results: The results demonstrated that CASC2 was significantly downregulated in clinical OSCC tissue samples and cultured OSCC cell lines. Low CASC2 expression was closely correlated with adverse clinicopathological characteristics of OSCC patients. Functionally, overexpression of CASC2 remarkably inhibited cell proliferation partly through inducing cell cycle arrest and cell apoptosis. Furthermore, bioinformatics analysis and dual-luciferase reporter assay showed that CASC2 might act as a competing endogenous RNA of miR-21 to promote the expression of PDCD4. Rescue experiments also showed that miR-21 blocked the tumor-suppressive role that CASC2 exerted in OSCC cells. Finally, in vivo study indicated that overexpression of CASC2 restrained OSCC tumor growth in volume and weight. Conclusion: In conclusion, these findings indicate that CASC2/miR-21/PDCD4 axis might be a potential regulator of OSCC tumorigenesis, and shed new light on lncRNA-directed diagnostics and therapeutics in OSCC.

miRNA-10a promotes cancer cell proliferation in oral squamous cell carcinoma by upregulating GLUT1 and promoting glucose metabolism

MicroRNA-10a (miRNA-10a) promotes lung cancer; however, to the best of our knowledge, its involvement in other cancer types is unknown. The present study aimed to investigate the role of miRNA-10a in oral cancer. Expression levels of miRNA-10a and glucose transporter 1 (GLUT1) in tumor tissues and adjacent healthy tissues obtained from patients with oral squamous cell carcinoma (OSCC) were detected by reverse transcription-quantitative polymerase chain reaction. Correlation analysis between the expression levels of miRNA-10a and GLUT1 was performed using Pearson's correlation coefficient. It was identified that miRNA-10a and GLUT1 were upregulated in tumor tissues compared with adjacent healthy tissues of patients with OSCC. Expression levels of miRNA-10a and GLUT1 were positively correlated in tumor tissues but not in adjacent healthy tissues. In addition, miRNA-10a overexpression promoted glucose uptake and upregulated GLUT1 in OSCC cells. Furthermore, GLUT1 overexpression promoted glucose uptake; however, no significant increase in the expression level of miRNA-10a in OSCC cells was detected. Overexpression of miRNA-10a and GLUT1 promoted OSCC cell proliferation, while GLUT1-knockdown inhibited OSCC cell proliferation. GLUT1-knockdown also attenuated the enhancing effect of miRNA-10a overexpression on cancer cell proliferation. Therefore, miRNA-10a may promote cancer cell proliferation in OSCC by upregulating GLUT1 and promoting glucose metabolism.

A three miRNAs signature for predicting the transformation of oral leukoplakia to oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) remains to be a global health problem. However, the underlying molecular mechanisms regulating the oral leukoplakia (OLK) to OSCC remain poorly known. MicroRNAs (miRNAs) expression profiles of GSE33299 and GSE62809 were downloaded from gene expression omnibus (GEO) respectively. R software and bioconductor packages were used to compare and identify the differentially expressed miRNAs between OLK tissues and OLK transformed OSCC (OLK-OSCC). The target genes of commonly changed miRNAs were then subjected to gene ontology (GO) enrichment analysis, pathway analysis and miRNA-target genes network analysis. The prediction power of commonly changed miRNAs was further tested in an independent cohort. In total, 161 (88 upregulated and 73 downregulated) and 68 (19 upregulated and 49 downregulated) markedly altered miRNAs were identified from GSE33299 and GSE62809 respectively. The downstream targets of these differentially expression miRNAs in the two cohorts shared many top enriched GO and KEGG pathways. A set of three miRNAs signature including miR-129-5p, miR-296-5p and miR-450b-5p was commonly changed in both GSE33299 and GSE62809. Functional analysis revealed that the downstream target genes of the miRNA signature were associates with transcriptional regulation, estrogen signaling pathway, p53 signaling pathway and RIG-I-like receptor signaling pathway. This three-gene signature was further successfully validated in another independent cohort. The expression levels of miR-129-5p and miR-296-5p were significantly downregulated in OLK-OSCC tissues compared to OLK tissues, while miR-450b-5p levels were higher in OLK-OSCC tissues. In addition, this three miRNAs signature could discriminate OLK from OLK-OSCC with high accuracy. In conclusion, our study has identified a three miRNAs signature that might help predict the transformation of OLK to OSCC. Which will provide useful guidance for therapeutic applications.

Genetic and epigenetic alterations in the tumour, tumour margins, and normal buccal mucosa of patients with oral cancer

Despite adequate surgical resection, oral squamous cell carcinoma (OSCC) shows a high rate of recurrence and metastasis, which could be explained by the presence of molecular alterations in seemingly normal tumour margins and the entire oral mucosa. The aims of this study were (1) to assess the presence of gene amplification (c-Myc and HER2) and promoter methylation (p14 and p16) in the tumours, tumour margins, and unaffected oral mucosa of 40 OSCC patients, and (2) to evaluate the possibility of using these alterations as prognostic markers. c-Myc and HER2 genes were quantified by means of real-time PCR (qPCR), and p14 and p16 methylation status was determined by methylation-specific PCR (MSP PCR). All tissues examined exhibited molecular alterations in various proportions. Tumour tissues, as expected, showed the highest prevalence of alterations, while oral mucosa showed the lowest. Multiple alterations (co-alterations) in tumours and tumour margins were significantly more frequent than in unaffected oral mucosa (P<0.001 and P=0.027, respectively). HER2 amplification in margin tissue (P<0.001) and swabs (P=0.013), as well as the existence of three co-alterations in margins (P=0.001) and macroscopically unaffected oral mucosa (P<0.001) were correlated with shorter disease-specific survival.

microRNA-1297 involves in the progression of oral squamous cell carcinoma through PTEN

Background

Oral squamous cell carcinoma (OSCC) oncogenic mechanisms still remain elusive. Herein, we proposed to understand the biological role of a newly discovered OSCC miRNA.

Methods

MiR-1297 related to OSCC was selected for this study. TaqMan qRT- PCR assay was used to profile miRNA and gene expression in 16 tumors with matched adjacent non-tumor tissues. CCK-8 assay and colony formation assay were used to demonstrate cell proliferation. Protein level was determined by western blotting. SPSS was used for statistical analyses.

Results

MiR-1297 is repressed and PTEN activated in OSCC. Moreover, the miR-1297 overexpressing cell lines displayed a decrease in cell growth rate. And, suppression of miR-1297 reversed the cell growth rate. In addition, PTEN silencing display the similar pattern as miRNA-1297 overexpression to enhance OSCC cell growth.

Conclusions

MiRNA and gene expression changes are common event in OSCC. Our results suggest miR-1297 may drive tumor progression through PTEN. And, miR-1297 could be a promising candidate for future investigation.

Prognostic indicators of improved survival and quality of life in surgically treated oral cancer

OBJECTIVE

No published study has analyzed the prognostic factors of surgically treated oral squamous cell carcinoma (OSCC) in relation to both survival and quality of life (QoL). The aim of this study was to analyze postoperative QoL in relation to survival to identify which parameters can predict the long-term outcome allowing the best QoL.

STUDY DESIGN

This retrospective cohort study considered 167 patients affected by OSCC treated surgically at the Otolaryngology Department of Cattinara Hospital (Trieste, Italy) by a single surgeon. We collected data about the main prognostic factors and the postoperative QoL 12 month after surgery.

RESULTS

The 5-year overall survival rate was equal to 68.1%, and the 5-year disease-specific survival was 77.8%. In this sample, 32% of patients also underwent adjuvant chemoradiotherapy. On stepwise Cox regression, the best predictors of disease-specific survival were the N stage (P < .001) and tumor depth of invasion (P < .001). QoL was affected by N stage, depth of invasion, invasive surgical approach, radiotherapy, and neck dissection (P < .05).

CONCLUSION

The prognostic factors that affect both survival rates and residual QoL are the surgical approach, the neck stage, and the depth of invasion, all of which can be minimized by early diagnosis.

Expression of mucin-1 in oral squamous cell carcinoma and normal oral mucosa: An immunohistochemical study

Background:

Mucins are high-molecular-weight glycoproteins with a high O-linked carbohydrate content, which are synthesized by many secretory epithelial cells as membrane-bound and/or secreted products. Mucin-1 (MUC1) is a transmembrane mucin that protects and lubricates the mucous membranes of the human body and involves itself in various cellular functions such as growth, differentiation and signaling. An aberrant expression of MUC1 has been demonstrated in various human cancers. Many studies on MUC1 expression have been conducted on a variety of neoplastic lesions other than head-and-neck region. In this study, an attempt has been made to evaluate the MUC1 immunoexpression in oral squamous cell carcinoma (OSCC) and normal oral mucosa (NOM).

Aims:

This study aims to compare and correlate the immunoexpression of MUC1 in NOM and OSCC using immunohistochemical technique.

Settings and Design:

Thirty patients of OSCC formed the study group and thirty patients were included in the control group (NOM). Formalin-fixed paraffin wax blocks were prepared from the tissue samples obtained.

Materials and Methods:

Immunohistochemistry (IHC) for MUC1 was performed, and the overall percentage of positive cells along with distribution and localization of immunoexpression was studied.

Statistical Analysis:

Pearson's Chi-square test was used. P <0.05 was considered to be statistically significant.

Results:

In OSCC study group, MUC1-positive immunoreaction was observed in 21 (70%) cases out of 30. All the samples in control group were negative for MUC1 immunoexpression. The immunohistochemical expression of MUC1 in OSCC group was statistically significant when compared with normal control group, as P < 0.05 (Pearson's Chi-square).

Conclusions:

MUC1 is a reliable biomarker for the diagnosis of OSCC, but further studies are required to prove its role in prognosis.

Raman exfoliative cytology for oral precancer diagnosis

Oral premalignant lesions (OPLs) such as leukoplakia, erythroplakia, and oral submucous fibrosis, often precede oral cancer. Screening and management of these premalignant conditions can improve prognosis. Raman spectroscopy has previously demonstrated potential in the diagnosis of oral premalignant conditions (in vivo), detected viral infection, and identified cancer in both oral and cervical exfoliated cells (ex vivo). The potential of Raman exfoliative cytology (REC) in identifying premalignant conditions was investigated. Oral exfoliated samples were collected from healthy volunteers (n=20), healthy volunteers with tobacco habits (n=20), and oral premalignant conditions (n=27, OPL) using Cytobrush. Spectra were acquired using Raman microprobe. Spectral acquisition parameters were: λex: 785 nm, laser power: 40 mW, acquisition time: 15 s, and average: 3. Postspectral acquisition, cell pellet was subjected to Pap staining. Multivariate analysis was carried out using principal component analysis and principal component-linear discriminant analysis using both spectra- and patient-wise approaches in three- and two-group models. OPLs could be identified with ∼77% (spectra-wise) and ∼70% (patient-wise) sensitivity in the three-group model while with 86% (spectra-wise) and 83% (patient-wise) in the two-group model. Use of histopathologically confirmed premalignant cases and better sampling devices may help in development of improved standard models and also enhance the sensitivity of the method. Future longitudinal studies can help validate potential of REC in screening and monitoring high-risk populations and prognosis prediction of premalignant lesions.

Roles of miR-138 and ISG15 in oral squamous cell carcinoma

The aim of the present study was to investigate the roles of microRNA (miR)-138 and interferon-stimulated gene 15 (ISG15) in patients with oral squamous cell carcinoma (OSCC). miR-138 and ISG15 expression in cancer tissues was detected, and the influence on proliferation, migration and invasion of OSCC cell lines was assessed. Reverse transcription-quantitative polymerase chain reaction was performed to analyze the expression of miR-138 and ISG15 in resected cancer tissues and pericancerous tissues harvested from patients with OSCC. The protein level of ISG15 was determined via western blot analysis. The constructed pGCMV/EGFP/miR-138 plasmid was transfected into CAL27 and SCC-15 OSCC cell lines via a liposome method to upregulate miR-138 expression. The transfection efficiency was determined based on miR-138 expression levels, and changes in proliferation, migration and invasion were subsequently compared with those in untransfected cells. The expression of ISG15 mRNA and protein was also detected in OSCC cells. miR-138 was significantly downregulated (P<0.05) in cancer tissues compared with adjacent normal tissues in patients with OSCC, whereas ISG15 mRNA expression levels were significantly higher in pericancerous tissues (P<0.05). ISG15 protein levels were also significantly higher in pericancerous tissues (P<0.05). ISG15 protein and mRNA levels were significantly decreased in the transfected cells compared with the untransfected cells, which indicated that miR-138 overexpression inhibited ISG15 expression. Additionally, the invasion, migration and proliferation abilities of successfully transfected CAL27 and SCC-15 cells were significantly decreased compared with the untransfected cells (P<0.05). The results of the present study suggest that miR-138 functions as a tumor-suppressive miR and serves an important role in OSCC via regulating ISG15 expression. These findings suggest that miR-138 is able to inhibit the proliferation, migration and invasion of OSCC cell lines.