Recent advances in Oral Oncology 2007: epidemiology, aetiopathogenesis, diagnosis and prognostication

FTO Sensitizes Oral Squamous Cell Carcinoma to Ferroptosis via Suppressing ACSL3 and GPX4

Ferroptosis is a newly established form of regulated cell death characterized by intracellular lipid peroxidation and iron accumulation that may be a promising cancer treatment strategy. However, the function and therapeutic value of ferroptosis in oral squamous cell carcinoma (OSCC) remain inadequately understood. In the present study, we investigated the biological role of the fat mass and obesity-associated gene (FTO) in ferroptosis in the context of OSCC. We found that OSCC had greater potential for ferroptosis, and FTO is associated with ferroptosis. Furthermore, higher FTO expression sensitized OSCC cells to ferroptosis in vitro and in vivo. Mechanistically, FTO suppressed the expression of anti-ferroptotic factors, acyl-CoA synthetase long-chain family member 3 (ACSL3) and glutathione peroxidase 4 (GPX4), by demethylating the m6A modification on the mRNA of ACSL3 and GPX4 and decreasing their stability. Taken together, our findings revealed that FTO promotes ferroptosis through ACSL3 and GPX4 regulation. Thus, ferroptosis activation in OSCC with high FTO levels may serve as a potential therapeutic target.

Costimulatory Molecules OX40 and OX40L Upregulation in Oral Squamous Cell Carcinoma: A Blood-Based Study

OBJECTIVES

 This research aimed to determine OX40 and OX40L mRNA expression in blood samples of naive oral squamous cell carcinoma (OSCC) patients in different histological grades and clinical stages. The in silico analysis was performed using the STRING database for functional association and a better understanding of the interactions of OX40 and its ligand with other proteins.

MATERIALS AND METHODS

 In this study, we recruited 141 newly diagnosed patients of OSCC. Levels of OX40 and OX40L mRNA expression were explored using real-time quantitative polymerase chain reaction. An in silico tool was also utilized to evaluate the OX40/OX40L interactome.

RESULTS

 The results showed higher OX40 expressional levels in the late stage (23-fold) compared with the early stage (8.5-fold) (p = < 0.001). A similar trend was seen in OX40L mRNA expression, revealing a fold change of 5.8 in the early stage in comparison to 9.9-fold change in the late stage (p = < 0.001). Overexpression of OX40 and OX40L was found in different histological grades (p = 0.005 and p = < 0.001, respectively). Overexpression of OX40 and OX40L was detected in habits such as smoking and paan intake, whereas statistically significant upregulation was observed in the cheek, lip, and alveolus tumors. However, there was no substantial difference in OX40 and OX40L expression based on age or gender. The functional interactions, that is, interactomes of OX40 and OX40L with other proteins have been determined by in silico analysis.

CONCLUSION

 Based on current study findings, despite OX40 and OX40L upregulation in newly diagnosed OSCC patients, it is speculated that the physiological function of these molecules is altered due to immune system exhaustion.

Systematic classification of confocal laser endomicroscopy for the diagnosis of oral cavity carcinoma

INTRODUCTION

Confocal laser endomicroscopy (CLE) is an optical imaging technique that allows in vivo microscope-like images of the upper aerodigestive tract's mucosa in 1000-fold magnification. The assessment of morphological tissue characteristics for the correct differentiation between healthy and malignoma suspected mucosa requires strict evaluation criteria. This study aims to validate a score for oral cavity squamous cell carcinoma (OCSCC) diagnostic.

METHODS

We performed CLE and examined a total of twelve patients. All 95 sequences (778 s, 6224 images) originate from the area of the primary tumor 260 s, 2080 images) and unsuspicious mucosa of the oral cavity (518 s, 4144 images). Specimen were taken at corresponding locations and analyzed histologically in H&E staining as a reference standard. A total of eight examiners (four experienced and four inexperienced) evaluated the sequences based on a scoring system. The primary endpoints are sensitivity, specificity, and accuracy. Secondary endpoints are inter-rater reliability and receiver operator characteristics.

RESULTS

Healthy mucosa showed epithelium with uniform size and shape with distinct cytoplasmic membranes and regular vessel architecture. CLE of malignant cells demonstrated a disorganized arrangement of variable cellular morphology. We calculated an accuracy, sensitivity, specificity, PPV, and NPV of 88.7 %, 90.1 %, 87.4 %, 87.5 %, and 90.0 %, respectively, with inter-rater reliability and κ-value of 0.775, and an area under the curve of 0.935.

CONCLUSIONS

The results confirm that this scoring system is applicable in the oral cavity mucosa to classify benign and malignant tissue.

Identification of autophagy-related biomarker and analysis of immune infiltrates in oral carcinoma

Background

Autophagy plays a vital role in the progression of the tumor. We aimed to investigate the expression, prognostic value, and immune infiltration of autophagy‐related genes in oral carcinoma via bioinformatics analysis.

Methods

The microarray datasets (GSE146483 and GSE23558) of oral carcinoma were downloaded from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between normal and diseased groups were identified by the Limma package. The screened autophagy‐related gene was further validated by the human protein atlas (HPA) database, TCGA database, and GSE78060 dataset.

Results

A total of 18 upregulated (top 10: EGFR, TNF, FADD, AURKA, E2F1, CHEK1, BRCA1, BIRC5, EIF2AK2, and CSF2) and 31 downregulated (top 10: MAP1LC3A, PARK2, AGT, IGF1, TP53INP1, CXCL12, IKBKB, SESN1, ULK2, and RRAGD) autophagy‐related (DEGs) were identified, and FADD was found to be related to the prognosis of oral cancer patients. Gene set enrichment analysis indicated that FADD‐associated genes were significantly enriched in immune‐related pathways. Moreover, correlation analysis revealed that FADD expression was associated with immune infiltrates. Upregulation of FADD is associated with poor survival and immune infiltrates in oral cancer.

Conclusion

We speculated that FADD is involved in the immune regulation of oral cancer, as well as autophagy.

Long non-coding RNA LINC00472 inhibits oral squamous cell carcinoma via miR-4311/GNG7 axis

Emerging studies indicate that long non-coding RNAs play important roles in oral squamous cell carcinoma (OSCC). However, the function of the majority of long non-coding RNAs is still unclear. Recently, LINC00472 has been reported to play crucial roles in multiple cancers. However, the role of LINC00472 in oral squamous cell carcinoma (OSCC) is still not clear. This study found that LncRNA LINC00472 was significantly down-regulated in several squamous cell carcinoma cancer tissues and OSCC cell lines. Over-expression of LINC00472 in OSCC cells inhibited OSCC progression and alleviated OSCC immune responses. Additionally, we confirmed that LINC00472 functioned as an hsa-miR-4311 sponge and regulated the expression of GNG7 (guanine nucleotide-binding protein, gamma 7). Also, we found that LINC00472 over-expression could suppress xenograft tumor growth in vivo. Our study provides evidence that LINC00472 plays an essential role in inhibiting oral squamous cell carcinoma progression and affecting immune responses by directly binding to hsa-miR-4311 to regulate the expression of GNG7 positively.

Gene therapy with SOCS1 induces potent preclinical antitumor activities in oral squamous cell carcinoma

BACKGROUND

Constitutive activation of STAT3 promotes oncogenesis and growth of oral squamous cell carcinoma (OSCC). We investigated the mechanism of action of suppressor of cytokine signaling 1 (SOCS1), an endogenous inhibitor of JAK, as gene therapy for OSCC.

METHODS

Antitumor effect of SOCS1 was compared to JAK inhibitor I by cell proliferation assay, cell cycle analysis, and apoptosis analysis in vitro. In addition, antitumor effect was evaluated using xenograft mouse models in vivo.

RESULTS

JAK inhibitor I inhibited the proliferation of KOSC2 cl3-43 or T3M-1 clone2 OSCC cell lines in vitro. While JAK inhibitor I arrested both cell lines at the G2/M phase, induction of apoptosis was observed in T3M-1 clone2 cells, but not KOSC2-cl3-43 cells. An adenoviral vector expressing SOCS1 (AdSOCS1) significantly decreased the proliferation of both OSCC cell lines and induced G2/M phase cell cycle arrest and apoptosis, suggesting that induction of apoptosis of KOSC2 cl3-43 cells by AdSOCS1 is regulated by the JAK/STAT independent pathway. Overexpression of SOCS1 inhibited activation of the JAK/STAT and p44/42 MAPK pathways, while JAK inhibitor I inhibited activation of the JAK/STAT pathway only. Consistently, expression of Mcl-1 was decreased by overexpression of SOCS1, but not JAK inhibitor I. Additionally, KOSC2 cl3-43 or T3M-1 clone2 OSCC cells were subcutaneously implanted in the flanks of two xenograft mouse models. As compared to a control adenovirus vector (AdLacZ), intratumor injection of AdSOCS1 significantly decreased the tumor volume and induced apoptosis in vivo.

CONCLUSION

SOCS1 gene therapy may be a beneficial approach for the treatment of OSCC.

Kallikrein 5 Inhibition by the Lympho-Epithelial Kazal-Type Related Inhibitor Hinders Matriptase-Dependent Carcinogenesis

Head and neck squamous cell carcinoma remains challenging to treat with no improvement in survival rates over the past 50 years. Thus, there is an urgent need to discover more reliable therapeutic targets and biomarkers for HNSCC. Matriptase, a type-II transmembrane serine protease, induces malignant transformation in epithelial stem cells through proteolytic activation of pro-HGF and PAR-2, triggering PI3K-AKT-mTOR and NFKB signaling. The serine protease inhibitor lympho-epithelial Kazal-type-related inhibitor (LEKTI) inhibits the matriptase-driven proteolytic pathway, directly blocking kallikreins in epithelial differentiation. Hence, we hypothesized LEKTI could inhibit matriptase-dependent squamous cell carcinogenesis, thus implicating kallikreins in this process. Double-transgenic mice with simultaneous expression of matriptase and LEKTI under the keratin-5 promoter showed a prominent rescue of K5-Matriptase^+/0 premalignant phenotype. Notably, in DMBA-induced SCC, heterotopic co-expression of LEKTI and matriptase delayed matriptase-driven tumor incidence and progression. Co-expression of LEKTI reverted altered Kallikrein-5 expression observed in the skin of K5-Matriptase^+/0 mice, indicating that matriptase-dependent proteolytic pathway inhibition by LEKTI occurs through kallikreins. Moreover, we showed that Kallikrein-5 is necessary for PAR-2-mediated IL-8 release, YAP1-TAZ/TEAD activation, and matriptase-mediated oral squamous cell carcinoma migration. Collectively, our data identify a third signaling pathway for matriptase-dependent carcinogenesis in vivo. These findings are critical for the identification of more reliable biomarkers and effective therapeutic targets in Head and Neck cancer.

Novel Autophagy-Related Gene Signature Investigation for Patients With Oral Squamous Cell Carcinoma

The correlation between autophagy defects and oral squamous cell carcinoma (OSCC) has been previously studied, but only based on a limited number of autophagy-related genes in cell lines or animal models. The aim of the present study was to analyze differentially expressed autophagy-related genes through The Cancer Genome Atlas (TCGA) database to explore enriched pathways and potential biological function. Based on TCGA database, a signature composed of four autophagy-related genes (CDKN2A, NKX2-3, NRG3, and FADD) was established by using multivariate Cox regression models and two Gene Expression Omnibus datasets were applied for external validation. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to study the function of autophagy-related genes and their pathways. The most significant GO and KEGG pathways were enriched in several key pathways that were related to the progression of autophagy and OSCC. Furthermore, a prognostic risk score was constructed based on the four genes; patients were then divided into two groups (i.e., high risk and low risk) in terms of the median of risk score. Prognosis of the two groups and results showed that patients at the low-risk group had a much better prognosis than those at the high-risk group, regardless of whether they were in the training datasets or validation datasets. Multivariate Cox regression results indicated that the risk score of the autophagy-related gene signatures could greatly predict the prognosis of patients after controlling for several clinical covariates. The findings of the present study revealed that autophagy-related gene signatures play an important role in OSCC and are potential prognostic biomarkers and therapeutic targets.

Serum Levels of OX40 in Early and Late-Stage Oral Squamous Cell Carcinoma

Background

The tumor necrosis factor receptor superfamily, member 4 (OX40) and its ligand (OX40L) are members of the tumor necrosis factor superfamily and play roles as costimulatory immunomodulators to combat infectious diseases as well as cancers. Presently, many therapeutic agents focused on OX40 and OX40L are in trials for antitumor efficacy. In Pakistan, oral squamous cell carcinoma (OSCC) is the second most prevalent cancer with a mortality of 50% despite the availability of various therapeutic modalities. Data regarding serum levels of OX40 in patients with OSCC is lacking. Therefore, the study aimed to assess the OX40 levels in serum and their association with the clinicopathological features of the tumor.

Methodology

A cross-sectional study was conducted and serum samples of 78 biopsy-confirmed OSCC patients were collected prior to any treatment along with 10 healthy persons after informed consent. Serum levels of OX40 were measured via sandwich enzyme-linked immunosorbent assay (ELISA).

Results

The mean serum levels of OX40 were 1.65 ± 0.64 ng/ml and 2.39 ± 0.58 ng/ml in early and late-stage disease patients of OSCC, respectively (p =<0.005). However, based on gender and tumor site, male gender and buccal mucosa tumors in late-stage OSCC patients showed higher mean levels of OX40, 2.42± 0.58 ng/ml and 2.41 ± 0.58 ng/ml (p =<0.05), respectively. Patients with well-differentiated tumors demonstrated mean serum levels of 2.28 ng/ml, and in moderately differentiated tumors, the mean levels were 2.19 ng/ml (p =0.47).

Conclusions

A high OX40 level is associated with advanced-stage disease and a poor prognosis, possibly reflecting the immune-exhausted status against OSCC.

Photodynamic therapy in the treatment of oral squamous cell carcinoma - The state of the art in preclinical research on the animal model

BACKGROUND

Oral cavity squamous cell carcinoma is a common cancer of the head and neck region. Due to the frequency of diagnoses, high rate of mortality, mutilating nature of classic therapy and numerous complications, new methods of treatment are being sought. One promising solution for treatment that is utilized in many fields of oncology is photodynamic therapy. The purpose of this article is to present a general overview of the use of photodynamic therapy in preclinical in vivo studies on the animal model.

MATERIAL AND METHODS

A literature search for articles corresponding to the topic of this review was performed using the PubMed and MEDLINE databases using the following keywords: 'oral cavity squamous cell carcinoma,' 'photodynamic therapy,' 'photosensitizer(s),' 'in vivo', and 'animal model'.

RESULTS

Based on the literature review, the two most used animal models can be distinguished in research on the use of photodynamic therapy for oral squamous cell carcinoma. Studies mainly focus on the evaluation of tumor growth inhibition after using therapies with various photosensitizers on the murine or hamster cheek pouch models.

CONCLUDING REMARKS

The animal model is a part of preclinical research. Unfortunately, each of the models has its limitations, so it is difficult to extrapolate the results to clinical trials.

Epidemiological and histopathological characteristics of head and neck cancers in Bhutan from 2011 to 2017: a retrospective descriptive study

BACKGROUND

Head and neck cancers are among the commonest cancers in the developing world. Personal habits, such as the use of tobacco, betel nut and alcohol are strongly associated with the development of head and neck cancers at certain sites. Therefore, they are among the preventable cancers. In Bhutan, there has not yet been a study conducted on head and neck cancers.

OBJECTIVE

To describe baseline epidemiological and histopathological characteristics of head and neck cancers in Bhutan.

METHODS

This is a 7-year descriptive study of all cases of head and neck cancers presented at the Jigme Dorji Wangchuk National Referral Hospital from 2011 to 2017. The data were collected from the hospital's medical records section, histopathology records, patient referral unit and some treatment centres in India. Prior approval was sought from the Research and Ethics Board for Health, the Ministry of Health and the hospital management.

RESULTS

There were a total of 515 cases of head and neck cancers from 2011 to 2017. The crude incidence rate was 10 per 100,000 and the overall age adjusted rate was 12.3 (95% CI 9.5-15.1) per 100,000 population. The prevalence during this 7-year period was 69.1 per 100,000 population. The commonest cancers are thyroid, oral cavity, hypopharyngeal, laryngeal and nasopharyngeal cancer in decreasing order. Head and neck cancers are more common in males than females in the majority of sites except thyroid, salivary gland and sinonasal malignancies. Thyroid cancers and nasopharyngeal cancers are found to affect younger age groups. Tashigang (48) followed by Paro (43) recorded the highest number of cases. Squamous cell carcinoma is the commonest histopathology type in almost all the cases, while papillary carcinoma is the commonest among thyroid cancers. Personal habits, such as smoking, chewing tobacco, betel nut and alcohol consumption, were found to be more common among patients suffering from oral cavity, laryngeal, hypopharyngeal and oropharyngeal cancers.

CONCLUSION

Head and neck cancers are the third most common cancer in Bhutan after stomach cancer and cervical cancer. Thyroid, oral cavity and hypopharynx are the top three anatomical sites for head and neck cancers in Bhutan. The current epidemiological and histopathological profile of head and neck cancers will form a baseline of information and basis for further research on head and neck cancers in Bhutan.

Anti-p53 Autoantibody Detection in Automatic Glass Capillary Immunoassay Platform for Screening of Oral Cavity Squamous Cell Carcinoma

The incidence of oral squamous cell carcinoma (OSCC), which is one of the most common cancers worldwide, has been increasing. Serum anti-p53 autoantibody is one of the most sensitive biomarkers for OSCC. Currently, the most commonly used method on clinical screening platforms is the enzyme-linked immunosorbent assay, owing to its high specificity and repeatability. However, conducting immunoassays on 96-well plates is typically time consuming, thereby limiting its clinical applications for fast diagnosis and immediate prognosis of rapidly progressive diseases. The present study performed immunoassays in glass capillaries of 1-mm internal diameter, which increases the surface to volume ratio of the reaction, to shorten the time needed for immunoassay. The immunoassay was automated while using linear motorized stages and a syringe pump. The results indicated that, when compared with the 96-well plate immunoassay, the glass capillary immunoassay decreased the reaction time from typical 120 min to 45 min, reduced the amount of reagent from typical 50 µL to 15 µL, and required only simple equipment setup. Moreover, the limit of detection for glass capillary anti-p53 autoantibody immunoassay was 0.46 ng mL⁻¹, which is close to the 0.19 ng mL⁻¹ value of the conventional 96-well plate assay, and the glass capillary method had a broader detection range. The apparatus was used to detect the serum anti-p53 autoantibody concentration in clinical patients and compare its results with the conventional 96-well plate method results, which suggested that both of the methods detect the same trend in the relative concentration of serum anti-p53 autoantibody in healthy individuals or patients with OSCC.

ERK Activation Modulates Cancer Stemness and Motility of a Novel Mouse Oral Squamous Cell Carcinoma Cell Line

We established the NHRI-HN1 cell line from a mouse tongue tumor induced by 4-nitroquinoline 1-oxide (4-NQO)/arecoline, with further selection for cell stemness via in vitro sphere culture, to evaluate potential immunotherapies for oral squamous cell carcinoma (OSCC) in East and Southeast Asia. In vivo and in vitro phenotypic characterization, including tumor growth, immune modulator administration, gene expression, morphology, migration, invasion, and sphere formation assays, were conducted. NHRI-HN1 cells are capable of generating orthotopic tumors in syngeneic mice. Interestingly, immune stimulation via CpG oligodeoxynucleotide (CpG-ODN) dramatically reduced the tumor growth in NHRI-HN1 cell-injected syngeneic mice. The pathways enriched in genes that were differentially expressed in NHRI-HN1 cells when compared to non-tumorigenic cells were similar to those that were identified when comparing human OSCC and non-tumorous tissues. NHRI-HN1 cells have characteristics of epithelial-mesenchymal transition (EMT), including enhanced migration and invasion. NHRI-HN1 cells showed aggressive cell growth and sphere formation. The blockage of extracellular signal-regulated kinase (ERK) activation suppressed cell migration and reduced stemness characteristics in NHRI-HN1 cells, similar to human OSCC cell lines. Our data suggest that NHRI-HN1 cells, showing tumorigenic characteristics of EMT, cancer stemness, and ERK activation, are sufficient in modeling human OSCC and also competent for use in investigating oral cancer immunotherapies.

Oral squamous cell carcinoma of tongue: Histological risk assessment. A pilot study

BACKGROUND

More than 90% of malignant tumors diagnosed in the oral cavity are Oral Squamous Cell Carcinomas (OSCC) whose preferred location is the tongue. Classically, this disease has affected men preferentially, although recent studies suggest that trends are changing and the proportion of women with OSCC is increasing. In addition, the prevalence of oral cancer is also determined by some risk factors as alcohol consumption and tobacco. Currently, the Tumor, Node, Metastasis (TNM) classification is employed to defined tumor stage and based on this guide specific treatments are established. However, 5-year-survival does not exceed 50% of cases. The objective of this study is to determine whether a histological risk pattern indicative of higher recurrence might be present in T1-T2 tumors located in the anterior two thirds of the tongue.

MATERIAL AND METHODS

Samples from 26 patients with OSCC were analyzed and histological risk pattern of recurrent and non-recurrent tumors were compared. We have analyzed histological variables described in Anneroth and Brandwein-Gensler classifications. Additionally, we have also examined both clinical variables such as age, sex or comorbidities, as well as habits such as tobacco or alcohol consumption.

RESULTS

We found that sex (male) and keratinization degree (high or moderate) are directly related with OSCC recurrence. In fact, free illness time is lower in men and higher in those cases with minimal or no keratinization.

CONCLUSIONS

Based on the variables analyzed, it has not been possible to establish a histological risk pattern that, complementary to the TNM classification, could have a predictive role in these early-stage tongue carcinomas.

Potential Applications of Circulating Tumor DNA Technology as a Cancer Diagnostic Tool

Cancer is one of the greatest threats posed to society, necessitating appropriate diagnosis methods. Modern targeted therapies have greatly advanced the treatment of several solid tumors. The rational use of these agents requires optimal strategies for the rapid and accurate detection of targetable genomic alterations at the time of initial diagnosis and when acquired resistance to targeted therapies develops. Currently used techniques, such as tissue genotyping, have limitations such as difficulty in categorizing tumors, needing frequent sampling, and difficulty in obtaining samples. To overcome these issues, cost-effective and non-invasive methods are an urgent requisite, which would provide an insight into the real-time dynamics of cancers via circulating biomarkers. Circulating tumor DNA (ctDNA), commonly termed "liquid biopsy," has emerged as a new, promising non-invasive tool to detect biomarkers in several cancers. The present review aimed to understand the biological concept of ctDNA and its potential as a biomarker in cancer studies and the clinical utility of this evolutionary diagnostic technique.

QKI, a miR-200 target gene, suppresses epithelial-to-mesenchymal transition and tumor growth

The microRNA-200 (miR-200) family plays a major role in specifying epithelial phenotype by preventing expression of the transcription repressors ZEB1 and ZEB2, which are well-known regulators of the epithelial-to-mesenchymal transition (EMT) in epithelial tumors including oral squamous cell carcinoma (OSCC). Here, we elucidated whether miR-200 family members control RNA-binding protein quaking (QKI), a newly identified tumor suppressor that is regulated during EMT. We predicted that miR-200a and miR-200b could recognize QKI 3'-UTR by analyzing TargetScan and The Cancer Genome Atlas head and neck squamous cell carcinoma (HNSCC) dataset. Forced expression of miR-200b/a/429 inhibited expression of ZEB1/2 and decreased cell migration in OSCC cell lines CAL27 and HSC3. QKI expression was also suppressed by miR-200 overexpression, and the 3'-UTR of QKI mRNA was directly targeted by miR-200 in luciferase reporter assays. Interestingly, shRNA-mediated knockdown of QKI led to pronounced EMT and protumor effects in both in vitro and in vivo studies of OSCC. Furthermore, high expression of QKI protein is associated with favorable prognosis in surgically resected HNSCC and lung adenocarcinoma. In conclusion, QKI increases during EMT and is targeted by miR-200; while, it suppresses EMT and tumorigenesis. We suggest that QKI and miR-200 form a negative feedback loop to maintain homeostatic responses to EMT-inducing signals.

Nicotine promotes cervical metastasis of oral cancer by regulating peroxiredoxin 1 and epithelial-mesenchymal transition in mice

Background

Tobacco is a major risk factor for oral squamous cell carcinoma (OSCC). However, the role of nicotine in OSCC is not completely understood.

Materials and methods

To analyze the mechanisms of nicotine-induced cervical metastasis, we investigated whether nicotine induced invasion, migration, and epithelial–mesenchymal transition (EMT) via regulating peroxiredoxin 1 (Prx1) in CAL 27 cells. In addition, we established a mouse model to confirm the roles of nicotine in regulating Ets1/Prx1/EMT signaling in OSCC metastasis.

Results

We showed that nicotine induced CAL 27 cell invasion, migration, EMT, and Prx1 and Ets1 expression. Prx1 knockdown inhibited cell invasion, migration, and EMT. Ets1 silencing downregulated Prx1 expression and EMT. Prx1 and Ets1 were shown to interact in CAL 27 cells treated with nicotine, and nicotine could significantly upregulate the binding of the transcription factor Ets1 to the Prx1 gene promoter region. Additionally, an in vivo study showed that nicotine induced tumor metastasis and EMT. Prx1 knockdown inhibited cervical metastasis rates and EMT progression. No significant differences in metastasis rates and EMT-related marker expression levels were observed between vehicle- and nicotine-treated mice.

Conclusion

The results indicate that nicotine promotes cervical lymph node metastasis through regulating Ets1/Prx1/EMT signaling during OSCC pathogenesis; consequently, Prx1 may represent a potential target for the prevention and treatment of OSCC.

Novel prognostic histopathological grading system in oral squamous cell carcinoma based on tumour budding and cell nest size shows high interobserver and intraobserver concordance

AIMS

Squamous cell carcinoma of the oral cavity (OSCC) is a common tumour entity with a variable, partially highly aggressive clinical course. Recently, we proposed a novel (three-tiered) clinically useful grading scheme strongly associated with patient outcome in OSCC, consisting of a sum score of the histomorphological patterns tumour budding and cell nest size which outperforms WHO based grading algorithms currently in use. The aim of our study was to probe for interobserver and intraobserver reliability of this novel grading system.

METHODS

108 OSCC were retrospectively scored according to the proposed grading scheme by three independent pathologists-two experienced head and neck pathologists and one pathologist in training-blinded to each other's scoring results.

RESULTS

The Cohen's Kappa (κ) values for concordance rates between experienced pathologists were κ=0.97 for the overall grade, κ=0.97 for budding activity and κ=0.91 for cell nest size, indicating a strong interobserver reliability of our proposed grading system. Initial interobserver agreement was markedly lower with the pathologist in training (κ=0.55 for overall grade) but improved significantly after a training session (κ=0.87 for overall grade). Intraobserver concordance was high (κ=0.95 for overall grade), indicating a high reproducibility of the algorithm.

CONCLUSIONS

In conclusion, our study indicates that OSCC grading based on our proposed novel scheme yields an excellent inter-reader and intrareader agreement, further supporting the suitability of this grading system for routine pathological practice.

ALDH1 as a prognostic marker for lymph node metastasis in OSCC

Long-term survival in cases of head and neck squamous cell carcinoma, particularly oral squamous cell carcinoma (OSCC), remains a rare achievement in the field of clinical oncology. In recent years, the theory of cancer stem cells (CSCs) has emerged and been used to offer explanations for tumour recurrence and metastasis. The present aim was to investigate the role of aldehyde dehydrogenase 1 (ALDH1) as a CSC-marker for OSCC and to determine the role of p16^ink4a, which is also a surrogate marker of human papilloma virus (HPV), in the expression of ALDH1. The study cohort comprised of 186 surgically-treated cases of OSCC. The primaries were located in the oral cavity. The expression of the CSC marker (CSCM) ALDH1 was evaluated via immunohistochemistry (IHC) of a tissue microarray. HPV detection was performed by polymerase chain reaction and an HPV Array kit. Furthermore, the IHC expression of p16^ink4a was also analysed. Risk regression models as the Kruskal Wallis test was used to assess the association of CSCM and p16^ink4a expression with tumour size and lymph node metastasis, and cox proportional hazards were analysed. Additionally, coexpression of the markers ALDH1 and p16^ink4a was analysed with regard to associations with tumour classification. Overall, high expression of ALDH1 in lymph nodes was significantly associated with Union for International Cancer Control (UICC) stage IV (P=0.044) and T4 stage cancer (P=0.03). p16^ink4a positivity, in cases of HPV negativity, was associated with worse survival rate compared with that of the total cohort (P=0.048). Collectively the data indicate that ALDH1 expression may be suitable for detection of unfavourable prognosis in OSCC patients, based in part on its apparent role as a marker of metastasis. HPV status was not statistically predictive of patient outcome or CSCM expression; however, p16^ink4a remains a potential marker in HNSCC Further in vitro studies with ALDH1 and p16^ink4a should be performed to evaluate the expression of ALDH1 and HPV in cell culture and to clarify the role of ALDH1 as a marker for increased invasiveness of OSCC cells.

Current mouse models of oral squamous cell carcinoma: Genetic and chemically induced models

Oral squamous cell carcinoma (OSCC) patients have a low 5-year survival rate and poor prognosis. To improve survival and prognosis, the causes and processes involved in lesion development should be evaluated. For this purpose, the use of OSCC mouse models, such as chemically induced mouse models, genetically modified mouse models, and transplanted (xenograft) models, is crucial. These OSCC models exhibit both advantages and disadvantages when studying OSCC development and progression. Until a model resembling human OSCC is developed, both the advantages and disadvantages of each model should be carefully considered. In this review, we discuss OSCC mouse models and their use in cancer research worldwide.

Anatomical locations in the oral cavity where surgical resections of oral squamous cell carcinomas are associated with a close or positive margin-a retrospective study

OBJECTIVES

This study aimed to identify anatomical areas where resections of oral squamous cell carcinomas (OSCC) are significantly associated with close or positive margins.

MATERIALS AND METHODS

This retrospective study included 330 patients with a primary OSCC from 2010 to 2015. Patient and tumour data were categorised into three groups by R-status (R0 [clear], ≥ 5 mm, 185 patients [56.06%]; R1 [positive], < 1 mm, 24 patients [7.27%]; and R0 [close], 1-5 mm, 121 patients [36.67%]).

RESULTS

Areas where resections were significantly associated with close or positive margins were the hard palate (p < 0.001), buccal mucosa (p = 0.03), floor of the mouth (p = 0.004), lower alveolar ridge (p = 0.01), retromolar triangle (p = 0.005), and dorsal tongue (p = 0.02).

CONCLUSIONS

Anatomical areas were identified in the oral cavity where it is challenging to resect OSCCs with an adequate safety margin.

CLINICAL RELEVANCE

These results may enable surgeons to achieve a postulated safe distance during tumour resection, leading to a survival benefit for patients.

Attenuation of cancer-initiating cells stemness properties by abrogating S100A4 calcium binding ability in head and neck cancers

S100A4 is a calcium-binding protein capable of promoting epithelial-mesenchymal transition. Previously, we have demonstrated that S100A4 is required to sustain the head and neck cancer-initiating cells (HN-CICs) subpopulation. In this study, to further investigate the molecular mechanism, we established the head and neck squamous cell carcinoma (HNSCC) cell lines stably expressing mutant S100A4 proteins with defective calcium-binding sites on either N-terminal (NM) or C-terminal (CM), or a deletion of the last 15 amino-acid residues (CD). We showed that the NM, CM and CD harboring sphere cells that were enriched with HN-CICs population exhibited impaired stemness and malignant properties in vitro, as well as reduced tumor growth ability in vivo. Mechanistically, we demonstrated that mutant S100A4 proteins decreased the promoter activity of Nanog, likely through inhibition of p53. Moreover, the biophysical analyses of purified recombinant mutant S100A4 proteins suggest that both NM and CM mutant S100A4 were very similar to the WT S100A4 with subtle difference on the secondary structure, and that the CD mutant protein displayed the unexpected monomeric form in the solution phase.Taken together, our results suggest that both the calcium-binding ability and the C-terminal region of S100A4 are important for HN-CICs to sustain its stemness property and malignancy, and that the mechanism could be mediated by repressing p53 and subsequently activating the Nanog expression.

Optical lymph node detection system: A practical device to assist lymph node location in neck resection specimens

The status of lymph node (LN) metastasis, including the number and location of positive LNs, is a significant prognostic factor for oral squamous cell carcinoma (OSCC). Therefore, knowing the number and location of positive LNs is essential for prognosis. However, surgeons often have difficulty locating LNs. In the present study a practical device to improve the location of LNs in neck resection specimens was intoduced: the optical lymph nodes detection system (OLNDS). With the assistance of the OLNDS LNs were easier to locate and a significantly higher number of LNs were identified (P=0.006). The false detection rate was also significantly reduced compared with the traditional method (P=0.0034). The OLNDS was observed to be a valuable adjunct to the traditional method and may be useful for studying the value of LN metastasis in OSCC prognosis.

Downregulation of Notch4 - a prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma

Introduction

Oral verrucous carcinoma is a special form of well-differentiated squamous cell carcinoma which possesses specific clinical, morphologic and cytokinetic features that differ from other types of oral cancers and hence diagnosis requires immense experience in histopathology. Hence it is certainly important to distinguish such a lesion from other oral tumors as treatment strategies vary widely between them.

Objective

In search of a critical diagnostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma, Notch4 receptor, one of the key regulatory molecules of the Notch signaling family has been aberrantly activated in the progression of several types of tumors. However its function in oral verrucous carcinoma remains unexplored. Thus the present study aims in determining the differential expression pattern of Notch4 in oral verrucous carcinoma and oral squamous cell carcinoma.

Methods

Ten patients reported positive for oral cancer (5 patients with oral verrucous carcinoma and 5 patients with oral squamous cell carcinoma). Five normal tissue samples were also obtained and evaluated for clinicopathological parameters and immunohistochemistry, western blotting and real time polymerase chain reaction for Notch4 expression.

Results

Our results reveal that the expression of Notch4 was considerably high in oral squamous cell carcinoma lesions compared to normal tissue, whereas in oral verrucous carcinoma, irrespective of the clinicopathological features, complete regulação descendente of Notch4 was observed.

Conclusions

These preliminary findings strongly support the fact that Notch4 is downregulated in oral verrucous carcinoma and could be considered as a suitable prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma. This distinguishing marker can help in improving therapeutic options in patients diagnosed with oral verrucous carcinoma.

Evaluation of FGFR3 as a Therapeutic Target in Head and Neck Squamous Cell Carcinoma

BACKGROUND

Although head and neck squamous cell carcinoma (HNSCC) is the sixth most common tumour entity worldwide, it remains a clinical challenge. Large-scale explorative genomic projects have identified several genes as potential targets for therapy, including fibroblast growth factor receptor 3 (FGFR3).

AIMS

The aim of this study was to investigate the biological significance of wild-type and mutated FGFR3 to evaluate its potential as a novel therapeutic target in HNSCC.

METHODS

FGFR3 protein expression was analysed in a large HNSCC tissue cohort (n = 536) and FGFR3 mRNA expression from The Cancer Genome Atlas (TCGA; n = 520). Moreover, FGFR3 wild-type and mutant versions were overexpressed in vitro, and both proliferation and migration was assessed with and without BGJ398 (a specific FGFR1-3 inhibitor) treatment.

RESULTS

Although FGFR3 expression for both cohorts decreased during tumour progression, high FGFR3 expression levels were observed in a small subset of patients. In vitro, FGFR3 overexpression led to increased proliferation, whereas migration was not altered. Moreover, FGFR3-overexpressing cells were more sensitive to BGJ398. Cells overexpressing FGFR3 mutant versions showed increased proliferation compared to wild-type FGFR3 under serum-reduced conditions and were largely as sensitive as the wild-type protein to BGJ398.

CONCLUSIONS

Taken together, the results of this study demonstrate that although FGFR3 expression decreases during HNSSC progression, it plays an important role in tumour cell proliferation and thus may be a potential target for therapy in selected patients suffering from this dismal tumour entity.

Oral squamous cell carcinoma patients can be differentiated from healthy individuals with label-free serum proteomics

Background:

No blood biomarkers to detect early oral cavity squamous cell carcinoma (OSCC) without clinical signs exist – diagnosis is solely based on histology of a visible tumour. Most OSCC patients are diagnosed at advanced stage, which leads to significant morbidity and poor survival. Our aim was to find the serum screening or detection biomarkers in OSCC.

Methods:

Serum samples from patients with OSCC treated at the Department of Otorhinolaryngology – Head and Neck Surgery, Helsinki University Hospital (Finland) were collected. Age- and gender-matched healthy individuals served as controls. Quantitative label-free proteomics in high definition MS^E mode(HDMS^E) was performed on 13 patients and 12 healthy samples. Various statistical analyses were performed on quantitative proteomics data to obtain the most influential proteins, which classify the patients vs healthy samples.

Results:

In quantitative proteomic analysis (HDMS^E), 388 proteins were quantified in our pilot study. A complete separation between cases and controls was seen in supervised and unsupervised classification techniques such as orthogonal projections on latent structure-discriminant analysis (OPLS-DA) and self-organising maps. Using OPLS-DA S-plot, we identified a set of eight proteins that completely separated OSCC patients from healthy individuals.

Conclusions:

Although the tumour stages varied from I to IVa, these potential biomarkers were able to identify all OSCCs demonstrating their sensitivity to detect tumours of all stages. We are the first to suggest a set of serum biomarkers in our pilot study to be evaluated further as a diagnostic panel to detect preclinical OSCC in risk patients.

Association between miRNA-binding site polymorphisms in double-strand break repair genes and risk of recurrence in patients with squamous cell carcinomas of the non-oropharynx

Genetic polymorphisms at miRNA-binding sites may affect miRNA-mediated gene regulation. Thus, miRNA-binding site polymorphisms in double-strand break (DSB) repair genes may affect DNA repair capacity, which in turn could affect cancer prognosis. To determine whether miRNA-binding site polymorphisms in DSB repair genes are associated with the risk of recurrence of squamous cell carcinoma of the non-oropharynx (SCCNOP), we used a log-rank test and multivariable Cox models to evaluate the associations between miRNA-binding site polymorphisms in DSB repair genes and SCCNOP recurrence. Compared with patients without common homozygous genotypes, patients with the variant genotypes of ATM rs227091, LIG3 rs4796030, and RAD51 rs7180135 had significantly better disease-free survival (DFS) (log-rank P = 0.046, 0.002, and 0.041, respectively) and lower risk of disease recurrence [HR (95% CI) = 0.7 (0.6-0.9), 0.6 (0.5-0.9), and 0.7 (0.6-0.9), respectively]. Furthermore, patients with the variant genotypes of these 3 polymorphisms had significantly lower recurrence risk than those without common homozygous genotypes did [HR = 0.3 (95% CI = 0.2-0.7)]. Among patients who received chemoradiation, those with the individual or combined variant genotypes of the three polymorphisms had a significantly lower risk of disease recurrence than those with the individual or combined common homozygous genotypes did. The individual or combined variant genotypes of the ATM rs227091, LIG3 rs4796030, and RAD51 rs7180135 polymorphisms significantly modify the risk of SCCNOP recurrence, particularly for patients treated with chemoradiation. Future prospective studies with larger sample sizes are warranted to validate these findings to enable more effective personalized treatment for SCCNOP patients.

Genetic and epigenetic characterization of the tumors in a patient with a tongue primary tumor, a recurrence and a pharyngoesophageal second primary tumor

Background

The choice of therapeutic modality for oral carcinoma in recurrent or second primary tumors remains controversial, as the treatment modalities available might be reduced by the treatment of the first tumor, and the overall survival is lower when compared with patients with a single or first tumor. Identifying biomarkers that predict the risk of relapse and the response to treatment is an emerging clinical issue.

Case presentation

A Caucasian 49-years-old man was treated with chemotherapy followed by chemoradiotherapy for a primary left side tongue tumor, achieving a complete response. After 49-months of follow-up, a local recurrence was diagnosed. After 3 months, a second primary tumor at the pharyngoesophageal region was detected. Genomic and epigenetic characterization of these three tumors was performed using array Comparative Genomic Hybridization, Multiplex Ligation-dependent Probe Amplification (MLPA) and Methylation Specific MLPA.

Results

The three tumors of this patient shared several imbalances in all chromosomes excluding chromosomes 9, 20 and 22, where genes related to important functional mechanisms of tumorigenesis are mapped. The shared genomic imbalances, such as losses at 1p, 2p, 3p, 4q, 5q, 6q, 7q, 8p, 10p, 11q, 12p, 12q, 13q, 15q, 16p, 16q, 17p, 17q, 18q, 19p, 19q, 21q and Xp and gains at 3q, 7q, 14q and 15q showed a common clonal origin for the diagnosed relapses.

We identified some chromosomal imbalances and genes mapped in the chromosomes 2, 3, 4, 6, 7, 11, 14, 17, 18 and 22 as putative linked to chemoradioresistance and chemoradiosensitivity. We also observed that gains in short arm of chromosomes 6, 7, 8 and 18 were acquired after treatment of the primary tumor. We identified losses of VHL gene and promoter methylation of WT1 and GATA5 genes, as predictors of relapses.

Conclusions

A common clonal origin for the diagnosed relapses was observed and we identified some putative candidate biomarkers of prognosis, relapse risk and treatment response that could guide the development of management strategies for these patients.

A Fas Ligand (FasL)-Fused Humanized Antibody Against Tumor-Associated Glycoprotein 72 Selectively Exhibits the Cytotoxic Effect Against Oral Cancer Cells with a Low FasL/Fas Ratio

Altered expression of the Fas ligand (FasL)/Fas ratio exhibits a direct impact on the prognosis of cancer patients, and its impairment in cancer cells may lead to apoptosis resistance. Thus, the development of effective therapies targeting the FasL/Fas system may play an important role in the fight against cancer. In this study, we evaluated whether a fusion protein (hcc49scFv-FasL) comprising of the cytotoxicity domain of the FasL fused to a humanized antibody (CC49) against tumor-associated glycoprotein 72, which is expressed on oral squamous cell carcinoma (OSCC), can selectively kill OSCC cells with different FasL/Fas ratios. In clinical samples, the significantly low FasL and high Fas transcripts were observed in tumors compared with normal tissues. A lower FasL/Fas ratio was correlated with a worse prognosis of OSCC patients and higher proliferative and invasive abilities of OSCC cells. The hcc49scFv-FasL showed a selective cytotoxic effect on OSCC cells (Cal-27 and SAS) but not on normal oral keratinocytes cells (HOK) through apoptosis induction. Moreover, SAS cells harboring a lower FasL/Fas ratio than Cal-27 were more sensitive to the cytotoxic effect of hcc49scFv-FasL. Unlike wild-type FasL, hcc49scFv-FasL was not cleaved by matrix metalloproteinases and did not induce nonapoptotic signaling in SAS cells. In vivo, we found that hcc49scFv-FasL drastically reduced the formation of lymph node metastasis and decreased primary tumor growth in SAS orthotopic and subcutaneous xenograft tumor models. Collectively, our data indicate that a tumor-targeting antibody fused to the FasL can be a powerful tool for OSCC treatment, especially in populations with a low FasL/Fas ratio. Mol Cancer Ther; 16(6); 1102-13. ©2017 AACR.

Gold nanorods reflectance discriminate benign from malignant oral lesions

Nanoparticle-based contrast agents have been used as an imaging tool for selectively detecting cancerous processes. We aimed to evaluate the detection sensitivity of reflection measurements of gold nanorods (GNRs) bio-conjugated to anti-epidermal growth factor receptor (GNRs-EGFR) monoclonal antibodies in discriminating benign from premalignant and malignant human oral lesions. Tissue sections incubated with GNRs-EGFR and the reflectance spectrum was measured using hyperspectral microscopy. Reflectance intensity increased with the progression of the disease, lowest in the control group and increasing as the dysplastic changes increase (P<0.001 for linear trend of grade). Intensity was significantly higher in the moderate and severe dysplasias and cancer patients than in the controls and mild dysplasia (t test P=0.0003, Mann-Whitney P<0.0001). The GNRs reflection measurements can discriminate benign and mild dysplastic lesions from the more severe dysplasia and invasive cancer, suggesting an objective, not dependent on the qualification of a technician and with less interpretation errors.

Hypermethylation of IFN-γ in oral cancer tissues

OBJECTIVES

The study aimed to evaluate the methylation pattern of the interferon-gamma (IFN-γ) gene in oral cancer tissues compared with normal and benign oral disease tissues.

MATERIALS AND METHODS

The oral tissues were gained from the patients of 85 cases of oral squamous cell carcinoma (OSCC), 47 cases of oral dysplastic lesions, and 53 normal biopsies. IFN -γ methylation in oral tissues was verified through methylation-specific polymerase chain reaction (PCR) and DNA sequencing analyses, and the expression levels of IFN-γ messenger RNA (mRNA) and protein were detected using real-time reverse transcription (RT)-PCR and enzyme-linked immunosorbent assays, respectively. IFN-γ was localized in macrophages from oral tissues and detected via immunostaining.

RESULTS

IFN-γ mRNA and protein expression levels were evidently decreased in oral cancer tissues, whereas the IFN-γ methylation rate was significantly higher in malignant tumors than in benign and normal tissues (normal, 22.6%; benign, 38.3%; and cancer, 55.3%; P < 0.05). Furthermore, the expression of IFN-γ mRNA was significantly downregulated in oral tumors with methylation compared with tumors without methylation, as determined by real-time RT-PCR (4.76-fold difference; P < 0.05). Likewise, mRNA expression was downregulated by 6.79-fold in oral epithelial dysplasia tissues with methylation compared with those without methylation (P < 0.01). Co-immunostaining to detect MAC2 and IFN-γ demonstrated that macrophages comprised the main source of IFN-γ in oral tissues. IFN-γ methylation demonstrated a significant association with the clinical stage, histopathology grade, and primary tumor.

CONCLUSIONS

Aberrant IFN-γ promoter methylation may be involved in the process of tumorigenesis of oral cancer.

CLINICAL RELEVANCE

IFN-γ hypermethylation during the process of oral carcinogenesis could be useful for the clinical diagnosis and treatment for OSCC.

Plasma Levels of Endothelial Cell-Specific Molecule-1 as a Potential Biomarker of Oral Cancer Progression

In Taiwan, oral cancer is the fourth most common cancer and the most common malignancy with a poor prognosis. Endothelial cell-specific molecule-1 (ESM-1) is secreted by vascular endothelial cells in the liver, lungs, kidneys, and gastrointestinal tract. ESM-1 expression is associated with tumor prognosis, metastasis, and angiogenesis in many cancers. However, few studies have examined the association of plasma ESM-1 levels with oral squamous cell carcinoma (OSCC) progression. We measured the plasma ESM-1 levels of 438 male OSCC patients through a commercial enzyme-linked immunosorbent assay. The Cancer Genome Atlas (TCGA) dataset was also used to analyze the ESM-1 levels in 328 OSCC patients and 33 normal tissues. Our results revealed that the plasma levels of ESM-1 in OSCC patients were significantly associated with the tumor (T) status but not with the lymph node status, metastasis, and cell differentiation. TCGA bioinformatics database analysis revealed that ESM-1 expression was significantly higher in OSCC patients than in normal individuals (p < 0.05). In addition, the examination revealed similar results for the ESM-1 expression levels and pathological stage in OSCC. In conclusion, plasma ESM-1 is a novel biomarker for predicting the T status in OSCC patients.

Targeting DDR2 in head and neck squamous cell carcinoma with dasatinib

Squamous cell carcinoma of the head and neck (HNSCC) is the tenth most common tumor entity in men worldwide. Nevertheless therapeutic options are mostly limited to surgery and radio-chemotherapy resulting in 5-year survival rates of around 50%. Therefore new therapeutic options are urgently needed. During the last years, targeting of receptor tyrosine kinases has emerged as a promising strategy that can complement standard therapeutical approaches. Here, we aimed at investigating if the receptor tyrosine kinase DDR2 is a targetable structure in HNSCC. DDR2 expression was assessed on a large HNSCC cohort (554 patients) including primary tumors, lymph node metastases and recurrences and normal mucosa as control. Subsequently, DDR2 was stably overexpressed in two different cell lines (FaDu and HSC-3) using lentiviral technology. Different tumorigenic properties such as proliferation, migration, invasion, adhesion and anchorage independent growth were assessed with and without dasatinib treatment using in-vitro cell models and in-vivo zebrafish xenografts. DDR2 was overexpressed in all tumor tissues when compared to normal mucosa. DDR2 overexpression led to increased migration, invasion, adhesion and anchorage independent growth whereas proliferation remained unaltered. Upon dasatinib treatment migration, invasion and adhesion could be inhibited in-vitro and in-vivo whereas proliferation was unchanged. Our data suggest treatment with dasatinib as a promising new therapeutic option for patients suffering from DDR2 overexpressing HNSCC. Since dasatinib is already FDA-approved we propose to test this drug in clinical trials so that patients could directly benefit from this new treatment option.

Conventional clinical and prognostic variables in 150 oral squamous cell carcinoma cases from the indigenous population of Karachi

Objective:

To analyze clinical and prognostic variables of Oral Squamous Cell Carcinoma (OSCC) cases from the indigenous population of Karachi and to correlate with the common risk factor of tobacco habit.

Methods:

The study was conducted at Ziauddin University, Karachi. One hundred fifty OSCC cases were collected from the Oncology Department of Ziauddin University Hospital, North Nazimabad, Karachi and Otolaryngology ward of Civil Hospital, Karachi, during 2011 and 2015. The reporting included demographic details and variables like intra-oral subsites, clinical stage and histological grade. Recurrence of tumor after initial resection was also documented.

Results:

The patient’s population comprised of 98 males and 52 females. The mean age was 47.1± 12.22 (range:20-78 years). Maximum numbers were seen in the 41–50 years age group. Urdu-speaking community was the most affected ethnic group (n=75). Clinico-pathological analysis revealed that majority of cases were moderately differentiated (59%) and were either clinical stage II (35%) or IV (29%) tumors. The most common intra-oral subsite came out to be buccal mucosa of cheeks (56%) followed by lateral borders of tongue (21%), lips (13%), alveolar (6%), palate (2.6%) floor of mouth (1.3%), etc. Recurrence was observed in 08 out of 150 cases. All patients underwent primary resection±neck dissection and reconstruction where possible.

Conclusions:

Overall experience with oral squamous cell carcinoma shows that it has a high tendency for local invasion as well as dissemination to regional lymph nodes, i.e. cervical lymph nodes, both are associated with a poor prognosis. Preventable risk factor of tobacco chewing has been observed in majority of these cases.

Evaluation of salivary and serum lipid peroxidation, and glutathione in oral leukoplakia and oral squamous cell carcinoma

Lipid peroxidation induced by reactive oxygen species (ROS) is involved in the pathogenesis of malignancy. Overall, lipid peroxidation levels are indicated by malondialdehyde (MDA), which is the most frequently used biomarker to detect oxidative changes. Antioxidant defense systems such as glutathione (GSH) limit cell injury induced by ROS. Therefore, MDA and GSH can be used to monitor oxidative stress (OS). Hence, this study aimed to evaluate and compare both salivary and serum levels of MDA and GSH in oral leukoplakia and oral squamous cell carcinoma (OSCC) patients, and healthy controls. The study included 100 subjects comprising 30 apparently healthy controls, 30 patients with oral leukoplakia and 40 clinically and histologically diagnosed patients with OSCC. Saliva and blood samples were obtained and evaluated for MDA and GSH. The study revealed enhanced MDA levels in saliva and serum in oral leukoplakia and OSCC patients as compared to controls. On the other hand, significant decreases were seen in serum and salivary GSH levels in oral leukoplakia and OSCC patients as compared to controls. Augmentation of OS in blood and saliva is reflected by increase in MDA and decrease in GSH levels, indicating that tumor processes cause an imbalance of oxidant-antioxidant status in cell structures.

Lipocalin 2 prevents oral cancer metastasis through carbonic anhydrase IX inhibition and is associated with favourable prognosis

Lipocalin 2 (LCN2), a secreted glycoprotein, is up- or downregulated in different human cancers. At present, the functional role of LCN2 in the progression of oral squamous cell carcinoma (OSCC), which accounts for most head and neck cancers, remains poorly understood, particularly with respect to its involvement in invasion and metastasis. In this study, we observed that LCN2 expression decreased in patients with OSCC and lymph node metastasis compared with that in patients without metastasis. A higher LCN2 expression correlated with the survival of patients with OSCC. Furthermore, LCN2 overexpression in OSCC cells reduced in vitro migration and invasion and in vivo metastasis, whereas its silencing induced an increase in cell motility. Mechanistically, LCN2 inhibited the cell motility of OSCC cells through hypoxia-inducible factor (HIF)-1α-dependent transcriptional inhibition of the carbonic anhydrase IX (CAIX). CAIX overexpression relieved the migration inhibition imposed by LCN2 overexpression in OSCC cells. Moreover, a microRNA (miR) analysis revealed that LCN2 can suppress CAIX expression and cell migration through miR-4505 induction. Examination of tumour tissues from patients with OSCC and OSCC-transplanted mice revealed an inverse correlation between LCN2 and CAIX expression. Furthermore, patients with LCN2(strong)/CAIX(weak) revealed the lowest frequency of lymph node metastasis and the longest survival. Our findings suggest that LCN2 suppresses tumour metastasis by targeting the transcriptional and post-transcriptional regulation of CAIX in OSCC cells. LCN2 overexpression may be a novel OSCC treatment strategy and a useful biomarker for predicting OSCC progression.

Cyclin D1 and Ki-67 expression correlates to tumor staging in tongue squamous cell carcinoma

BACKGROUND

The immunohistochemical expression of Cyclin D1 and Ki-67 were analyzed in tongue squamous cell carcinomas (SCC), relating them to the clinical and morphological exhibition of these tumors.

MATERIAL AND METHODS

Twenty-nine patients fulfilled the inclusion criteria; clinical data included gender, age, ethnicity and use of licit drugs such as alcohol and tobacco. The TNM staging and histopathological differentiation grading was assessed for each case. In addition, T1 patients were gathered with T2 patients; and T3 patients were gathered with T4 patients to assemble two distinct groups: (T1/T2) and (T3/T4).

RESULTS

The mean follow-up time was 24 months and 30% of the patients died as a consequence of the disease, while 23.3% lived with the disease and 46.7% lived lesion-free. T1 and T2 tumors showed statistically lesser Ki-67 and Cyclin D1 staining when compared to T3 and T4 tumors.

CONCLUSIONS

Ki-67 and Cyclin D1 pose as auxiliary tools when determining the progression of tongue SCC at the time of diagnosis.

Loco-regional recurrence after surgical treatment of oral squamous cell carcinoma: Proposals for follow-up imaging based on literature, national guidelines and institutional experience

The recurrence rate following the treatment of oral squamous cell carcinoma (OSCC) by primary surgery is about 10%-26%. The earliest possible diagnosis of residual tumour, recurrence of local tumour disease, and subsequent metastasis is essential for an improvement of the overall survival and of the survival period for affected patients. No international consensus exists for a post-therapeutic surveillance schedule for OSCCs. Based on a review of the literature, existing guidelines, and our institutional experience, we have established an algorithm for the follow-up of these patients regarding the timing and techniques of postoperative imaging. We recommend a follow-up interval of 6 weeks during the first half-year after discharge from hospital by single clinical and alternating clinical check-ups combined with computed tomography (CT) or magnetic resonance imaging (MRI), followed by an interval of 3 months in the second half-year, with clinical and radiological check-ups. In year 2, we recommend a follow-up interval of 3 months with single clinical and alternating clinical check-ups combined with CT or MRI. In year 3, we recommend screening every 6 months, both clinically and via imaging, because of the decreased risk of recurrence. From year 5 onwards, our recommendation is a clinical and imaging-based examination every 6-12 months, depending on patient risk factors and disease progression. Four standard imaging techniques, namely positron emission tomography (PET), CT, MRI, and ultrasound (US), are discussed concerning their range of application, sensitivity, and specificity. Furthermore, the technical aspects of our institutional protocols are described in detail. In highly frequented head and neck cancer centres, PET and US are of secondary importance, since CT and MRI are nowadays highly efficient tools in primary diagnostic and post-therapeutic surveillance.

p63 and E-cadherin Expression in Canine Oral Squamous Cell Carcinoma

The expression of p63 and E-cadherin was studied in 22 oral squamous cell carcinomas in the dog according to immunohistochemical techniques. The association between these markers and clinicopathologic parameters was assessed. All tumor cells studied showed enhanced p63 expression. Regarding E-cadherin expression, 17 of 22 cases (77.3%) showed decreased immunoreactivity, and in 13 of 22 cases (59.1%), its expression was cytoplasmic. Neither p63 nor E-cadherin expression patterns were associated with tumor size, bone invasion, or lymph node metastasis. p63 score was related to proliferating cell nuclear antigen proliferative index (P = .020). A statistically significant correlation between the expression patterns of these 2 markers was noted (P = .026). Furthermore, they were related with tumor grade. An atypical p63 labeling and a cytoplasmic E-cadherin staining were statistically related with a higher tumor grade (P = .022 and P = .017, respectively). These findings suggest that changes in p63 and E-cadherin expression are frequent events in oral squamous cell carcinoma in dogs.

Induction of peroxiredoxin 1 by hypoxia regulates heme oxygenase-1 via NF-κB in oral cancer

Overexpression of peroxiredoxin 1 (Prx1) has been observed in numerous cancers including oral squamous cell carcinoma (OSCC). The precise molecular mechanism of up-regulation of Prx1 in carcinogenesis, however, is still poorly understood. The objective of this study is to investigate the relationship between Prx1 and hypoxia, and potential mechanism(s) of Prx1 in OSCC cell line SCC15 and xenograft model. We treated wild-type and Prx1 knockdown SCC15 cells with transient hypoxia followed by reoxygenation. We detected the condition of hypoxia, production of reactive oxygen species (ROS), and expression and/or activity of Prx1, heme oxygenase 1 (HO-1) and nuclear factor-kappa B (NF-κB). We found that hypoxia induces ROS accumulation, up-regulates Prx1, increases NF-κB translocation and DNA binding activity, and down-regulates HO-1 in vitro. In Prx1 knockdown cells, the expression level of HO-1 was increased, while NFκB translocation and DNA binding activity were decreased after hypoxia or hypoxia/reoxygenation treatment. Moreover, we mimicked the dynamic oxygenation tumor microenvironment in xenograft model and assessed the above indices in tumors with the maximal diameter of 2 mm, 5 mm, 10 mm or 15 mm, respectively. Our data showed that tumor hypoxic condition and expression of Prx1 are significantly associated with tumor growth. The expression of HO-1 and NF-κB, and NF-κB DNA binding activity were significantly elevated in 15 mm tumors, and the level of 8-hydroxydeoxyguanosine was increased in 10 mm and 15 mm tumors, compared to those in size of 2 mm. The results from this study provide experimental evidence that overexpression of Prx1 is associated with hypoxia, and Prx1/NF-κB/HO-1 signaling pathway may be involved in oral carcinogenesis.

Induction of Apoptosis and Cytotoxic Activities of Iranian Orthodox Black Tea Extract (BTE) Using in vitro Models

PURPOSE

Plant-derivate therapeutic agents can perform cancer chemotherapeutic activity through triggering apoptotic cell death. Our aim was to investigate the cytotoxic effects, induction of apoptosis, and the mechanism of cell death of Iranian orthodox black tea extracts (BTEs) and hydro methanolic purified fractions (40, 60, 80 and 100%) in KB cells (oral squamous cell carcinoma).

METHODS

In order to analyze the cytotoxic activity of the BTEs, MTT (3-(4, 5- dimetylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide) and Trypan-blue assays were performed in oral squamous cell carcinoma (KB). Furthermore, the apoptosis inducing action of the extracts was determined by TUNEL, DNA fragmentation and cell death detection analysis.

RESULTS

Dichloromethane BTE and hydro methanol fractions (40 and 60%) extract showed no cytotoxic effects; however, hydro methanol crude and hydro methanol fractions of BTE (80 and 100%) significantly inhibited cell growth and viability in a dose and time dependent manner. In addition, Cell death assay, TUNEL, and DNA fragmentation indicated induction of apoptosis by hydro methanol 80 and 100% fractions of BTE in KB cells. Statistical significance was determined by analysis of variance (ANOVA), followed by Duncan test and p value ≤0.05 was considered significant.

CONCLUSION

The results from the present study suggests that the hydro methanol crude and hydro methanol fractions of BTE (80 and 100%) are significant source of compounds with the anti proliferative and cytotoxic activities, and this may be useful for developing potential chemo preventive substances.

Diffusion Reflection: A Novel Method for Detection of Oral Cancer

Intraoperative detection of residual disease in oral cancer may reduce the high rate of recurrences. The aim of the present study was to evaluate the detection sensitivity of diffusion reflection (DR) measurements of bioconjugated gold nanorods (GNRs) to cancerous sites in a rat model of oral squamous cell carcinoma. We used hyperspectral spectroscopy and DR measurements of GNRs bioconjugated to slide specimens of rat tongues where squamous carcinoma was induced by 4NQO (4-nitroquinoline-N-oxide). Wistar-derived male rats were used: 6 were sacrificed at wk 32 to 37 following 4NQO administration (experimental rats), as were 2 control rats at wk 32 and 36. The detection results were compared with histopathology: 19 sites of cancerous changes were identified microscopically (11 invasive cancer and 8 carcinoma in situ [CIS]). The GNRs attached selectively to areas of carcinomatous changes with an intensity exceeding 17 intensity units at 780 nm (overall specificity, 97%; overall sensitivity, 87%) when the hyperspectral spectroscopy system was used. The resulting DR slopes of the reflected intensity showed an increase of >80% in areas of invasive cancer and an increase of >30% in the CIS sites. The resulting intensity units of the hyperspectral spectroscopy system in the invasive cancer significantly exceed those of the CIS (t test, p = .0002; Mann-Whitney, p = .0024). The results demonstrate a great potential of the direct DR scanning as a new and simple tool for detecting residual disease intraoperatively.