Advances and applications of oral cancer basic research

The involvement of epidermal growth factor receptor/protein kinase B signaling in the tumor intrinsic PD-L1-induced malignant potential of oral squamous cell carcinoma

BACKGROUND

Various antigen-presenting cells and tumor cells-expressing PD-L1 inhibits antitumor immune responses in the tumor microenvironment. Recently, numerous studies have shown that tumor cell intrinsic PD-L1 also plays important roles in tumor growth and progression. On the other hand, oral squamous cell carcinoma (OSCC) cells overexpress epidermal growth factor receptor (EGFR) and EGFR signal pathway exacerbates tumor progression. Therefore, this study assessed whether tumor-intrinsic PD-L1 facilitates malignant potential of OSCC cells through regulation of EGFR signaling.

METHODS

Two OSCC cell lines, SAS and HSC-3, were transfected with PD-L1 and EGFR-specific small interfering RNA (siRNA). Influences of PD-L1 knockdown on malignant potentials of OSCC cells were examined by Cell Counting kit-8 assay, transwell assay, sphere formation assay, flow cytometry, and Western blot. Effects of PD-L1 and EGFR knockdown on each expression were examined by quantitative real-time PCR (qRT-PCR), Western blot, and flow cytometry.

RESULTS

Transfection of an PD-L1-siRNA into OSCC cells decreased the abilities of proliferation, stemness, and mobility of these cells significantly. PD-L1 knockdown also decreased EGFR expression through the promotion of proteasome- and lysosome-mediated degradation and following activation of the EGFR/protekin kinase B (AKT) signal pathway. Meanwhile, EGFR knockdown did not influence PD-L1 expression in SAS and HSC-3 cells, but treatment with a recombinant human EGF induced its expression. Treatment with erlotinib and cetuximab suppressed rhEGF-induced PD-L1 expression and localization in the cellular membrane of both OSCC cells.

CONCLUSION

OSCC cells-expressing PD-L1 induced by EGF stimulation may promote malignancy intrinsically via the activation of the EGFR/AKT signaling cascade.

Genes involved in metastasis in oral squamous cell carcinoma: A systematic review

Background and Aims

Oral squamous cell carcinoma is the most prevalent malignancy in the oral cavity, with a significant mortality rate. In oral squamous cell carcinoma patients, the survival rate could decrease because of delayed diagnosis. Thus, prevention, early diagnosis, and appropriate treatment can effectively increase the survival rate in patients. In this systematic review, we discussed the role of different genes in oral squamous cell carcinoma metastasis. Herein, we aimed to summarize clinical results, regarding the potential genes that promote oral squamous cell carcinoma metastasis.

Methods

This systematic review was carried out under the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. An electronic search for all relevant articles published in English between January 2018 and April 2022 was performed using Scopus, PubMed, and Google Scholar search engines. All original studies published in English were included, and we excluded studies that were in a non-English language.

Results

A total of 4682 articles were found, of which 14 were relevant and detected significant genes in oral squamous cell carcinoma progression. These findings investigated the overexpression of interferon-induced proteins with tetratricopeptide repeats 1 and 3 (IFIT1, IFT3), high-mobility group A2 (HMGA2), transformed growth factor-beta-induced, lectin galactoside-binding soluble 3 binding protein (LGALS3BP), bromodomain containing 4, COP9 signaling complex 6, heterogeneous nuclear ribonucleoproteins A2B1 (HNRNPA2B1), 5'-3' exoribonuclease 2 (XRN2), cystatin-A (CSTA), fibroblast growth factors 8 (FGF8), forkhead box P3, cadherin-3, also known as P-cadherin and Wnt family member 5A, ubiquitin-specific-processing protease 7, and retinoic acid receptor responder protein 2 genes lead to promote metastasis in oral squamous cell carcinoma. Overexpression of some genes (IFIT1, 3, LGALS3BP, HMGA2, HNRNPA2B1, XRN2, CSTA, and FGF8) was proven to be correlated with poor survival rates in oral squamous cell carcinoma patients.

Conclusion

Studies suggest that metastatic genes indicate a poor prognosis for oral squamous cell carcinoma patients. Detecting these metastatic genes in oral squamous cell carcinoma patients may be of predictive value and can also facilitate assessing oral squamous cell carcinoma development and its response to treatment.

A clinicopathological exploration of Hedgehog signaling: implications in oral carcinogenesis

INTRODUCTION

Hedgehog Signaling, a basic cancer stem cell pathway, plays a major role during the embryonic development, is known to play a quiescent role in adults. However, aberrant activation of Hedgehog signaling in adults is known to play a role in cancer development. Hence, the aim of the study was to identify the role of Hedgehog signaling pathway in the Oral cancers.

MATERIALS AND METHODS

The expression of Hedgehog signaling pathway was evaluated in 124 patients through the quantitative real-time PCR. The association between the gene expression and clinico-pathological parameters were analyzed using the Pearson chi-square test and survival analysis was carried out using Kaplan-Meier analysis.

RESULTS

SHH and GLI1 was found to be significantly associated with the Lymph Node Status and SUFU was significantly associated with the Age. SMO and SUFU were found to have a worse prognosis in oral cancer patients. According to our findings, IHH plays a critical role in the activation of the HH signaling pathway in oral cancer.

CONCLUSION

These findings back up the use of the Hedgehog signaling pathway as a biomarker for early disease prediction in oral cancer, as well as its role in tumor aggressiveness and invasiveness.

Vitamin D in the Prevention and Treatment of Oral Cancer: A Scoping Review

Introduction: Oral cancer is a serious health problem with an increasing incidence worldwide. Researchers have studied the potential anti-cancerous action of vitamin D and its association with several cancers including oral cancer. The purpose of this scoping review is to synthesize the existing literature on the role of vitamin D on oral cancer. Methods: A scoping review of the literature was conducted using the framework developed by Arkey and O'Malley and the PRISMA-ScR guidelines. Nine databases were searched for peer-reviewed human studies published in English that either investigated the association of vitamin D with, or its impact on either the prevention or treatment of oral cancer. The authors then extracted data using a predefined form to summarize information about article type, study design, participant characteristics, interventions, and outcomes. Results: Fifteen articles met the review criteria. Among the 15 studies, 11 were case-control, 3 were cohort studies, and 1 was a clinical trial. In four studies, the evidence supported a preventive action of vitamin D against oral cancer and a reduction in the negative side effects associated with chemo- and radiotherapy. Several studies that focused on genetic polymorphisms and the expression of the 1,25 dihydroxyvitamin D3 receptor (VDR) suggested significant associations with vitamin D and increased oral cancer risk and worse survival rates. In contrast, two studies did not reveal a strong association between vitamin D and oral cancer. Conclusions: The current evidence suggests an association between vitamin D deficiency and an increased risk of oral cancer. VDR gene polymorphisms might also be a part of future preventive and therapeutic strategies against oral cancer. Carefully designed studies are required to explore and define what role, if any, vitamin D might play in the prevention and treatment of oral cancer.

Expression of CD24 as Cancer Stem Cell Marker in the Diagnosis of Oral Squamous Cell Carcinoma - A Prospective Study

Introduction

Oral squamous cell carcinoma (OSCC) is an aggressive and recurrent malignancy. Identification of unique and overexpressed cell surface antigens is important in the diagnosis and development of cancer vaccines and various therapies for OSCC. We have used real-time polymerase chain reaction (RT-PCR) for the expression of cell surface protein CD24 in both tissue samples and in blood samples to study the clinicopathological features as well as to determine the gene expression profile of CD24 in OSCC and explore its role as a potential target of clinical therapy.

Materials and Methods

In this prospective study, the expression of CD24 was evaluated in 20 blood (3 ml) and tissue samples of OSCC specimens by quantitative RT-PCR. Student's t-test was used for statistical analysis. The significance level was considered <0.05.

Results

CD24 was found to be upregulated amongst the cases for both the tissue and the blood. CD24 was statistically significant with P < 0.05. Fold change was calculated to assess the quantity of the difference in expression amongst cases when compared to controls. Results were supportive of CD24 being a reliable biomarker, hence blood samples can also be used in screening and diagnosis of OSCC.

Discussion

CD24 expression is significantly upregulated in blood and tissue samples in OSCC. In addition, CD24 overexpression is highly associated with adverse prognostic parameters such as lymph node involvement, advanced clinical stages and worse overall survival. Our findings have important implications in future practice, overexpression of CD24 in OSCC was associated with poor prognosis correlating to the clinical findings, large-scale comprehensive studies are needed further to confirm our findings. In addition to histological features, CD24 can be used as marker for OSCC.

CD24-gold nanocomposite as promising and sensitive biomarker for cancer stem cells in salivary gland tumors

Cancer stem cells are highly tumorigenic cells in the majority of the tumor that are responsible for the initiation, rapid growth, invasion, metastasis, and therapeutic resistance associated with various human cancers. The aim of this project is to assess a diagnostic and prognostic biomarker for the detection of cancer stem cells in salivary gland tumors using gold nanoparticles that are synthesized and conjugated to CD24 primer to form a CD24-Gold Nanocomposite. Sixty cases were included (29 pleomorphic adenoma, 19 carcinoma ex pleomorphic adenoma, and 12 normal controls). Alterations in biomarker expression between studied groups were analyzed and correlated with clinicopathological characteristics using Fisher's exact and Chi-square tests. ROC and Kaplan-Meier curves were used to validate diagnostic and prognostic values, respectively. This study confirms that CD24-Gold Nanocomposite served as a promising and highly sensitive biomarker in salivary gland tumor diagnosis and prognosis prediction.

Human papillomavirus, tobacco, and poor oral hygiene can act synergetically, modulate the expression of the nuclear factor kappa B signaling pathway for the development and progression of head and neck cancer in the Pakistani population

BACKGROUND

Head and neck cancers (HNCs) are a heterogeneous group of tumors that progress owing to varied enviromental and genetic risk factors. Viral infections are threatening and adept at altering the expression of cellular transcription factors such as nuclear factor kappa B (NF-κB) and deregulation of other cellular proteins like NF kappa B inhibitor alpha (IκBα). The present study was conducted to detect high-risk genotypes of human papillomavirus (HPV) and protein expression of NF-κB signaling pathway in HNC patients with HPV infection.

METHODS

For HPV detection, genomic DNA from 152 HNC tumors was extracted formalin-fixed paraffin-embedded tissue DNA kit. For genotyping, polymerase chain reaction (PCR) using a general primer, HPV type-specific primers and agarose gel electrophoresis were performed. Immunohistochemistry (IHC) was also performed on 4-μm thick tissue sections using HPV E6 monoclonal antibody. Protein expression analysis of NF-κB signaling pathway including p50, p65, and IκBα was performed using IHC.

RESULTS

PCR analysis showed that 24.3% (37/152) of HNC cases were HPV positive. Among HPV positive, 86.5% (32/37) were tobacco users, while among HPV negative, 66.9% (77/115) were tobacco users. A significant association of HPV positivity and tobacco user was observed by univariate analysis [ P   <  0.01; odds ratio (OR): 0.310, 95% confidence interval (CI): 0.110 to 0.870]. More HPV positive patients were with poor oral hygiene (78.3%) when compared with patients with good oral hygiene (21.6%) [ P  < 0.03, OR: 2.440, 95% CI: 1.650 to 3.600]. The results of the logistic regression analysis showed that age, tobacco use and oral hygiene are significant predictors ( P  < 0.02). PCR and IHC staining results confirmed that HPV16 was predominant among HNC cases (64.8%) when compared with HPV18 (35.2%). Expression of NF-κB proteins (p50, p65, and IκBα inhibitor) were also observed in HPV and non-HPV infected HNC tissues. IHC expression of p50, and p65 showed nuclear staining, while IκBα inhibitor showed cytoplasmic staining. Protein expression in HPV cases was higher as compared to HPV naive cases ( P  < 0.05).

CONCLUSIONS

From the study, it can be established that the use of tobacco, oral hygiene, and HPV infection may be synergistically involved in modulating the expression of NF-κB signaling pathway for the development and progression of HNC in the Pakistani population.

Substance P and Neurokinin 1 Receptor in Chronic Inflammation and Cancer of the Head and Neck: A Review of the Literature

Head and neck cancer is a growing worldwide public health problem, accounting for approximately 1,500,000 new cases and 500,000 deaths annually. Substance P (SP) is a peptide of the tachykinin family, which has roles related to a large number of physiological mechanisms in humans. The implications of SP in carcinogenesis have recently been reported through the stimulation of the neurokinin 1 receptor (NK1R), or directly, through the effects derived from the constitutive activation of NK1R. Consequently, SP/NK1R seems to play relevant roles in cancer, upregulating cell proliferation, cell migration and chronic inflammation, among other oncogenic actions. Furthermore, there is growing evidence pointing to a central role for SP in tumour progression, singularly so in laryngeal and oral squamous cell carcinomas. The current narrative review of the literature focuses on the relationship between the SP/NK1R system and chronic inflammation and cancer in the head-and-neck region. We described a role for SP/NK1R in the transition from chronic inflammation of the head and neck mucosa, to preneoplastic and neoplastic transformation and progression.

Epidermal growth factor/epidermal growth factor receptor signaling blockage inhibits tumor cell-derived exosome uptake by oral squamous cell carcinoma through macropinocytosis

Various cell types secrete exosomes into their surrounding extracellular space, which consequently affect the function and activity of recipient cells. Numerous studies have showed that tumor cell‐derived exosomes play important roles in tumor growth and progression. Although a variety of endocytic pathways are reportedly involved in the cellular uptake of exosomes, detailed mechanisms remain unknown. The present study demonstrated that treatment with recombinant epidermal growth factor (EGF) time‐ and dose‐dependently promoted cellular uptake of oral squamous cell carcinoma (OSCC) cell‐derived exosomes into OSCC cells themselves. Conversely, EGF receptor (EGFR) knockdown and treatment with EGFR inhibitors, including erlotinib and cetuximab, abrogated OSCC cell uptake of exosomes. The macropinocytosis inhibitor 5‐(N‐ethyl‐N‐isopropyl) amiloride (EIPA) blocked the effects of active EGF/EGFR signaling on uptake of OSCC cell‐derived exosomes. These EGFR inhibitors also suppressed OSCC cell‐derived exosome‐induced proliferation, migration, invasion, stemness, and chemoresistance of OSCC cells. Taken together, the data presented herein suggest that EGFR inhibitors might inhibit the malignant potential of OSCC cells through direct inhibition of not only EGFR downstream signaling pathway but also cellular uptake of OSCC cell‐derived exosomes through macropinocytosis.

Huanglianjiedu Decoction as an effective treatment for oral squamous cell carcinoma based on network pharmacology and experimental validation

Background

Oral squamous cell carcinoma (OSCC) is one of malignant tumors in oral and maxillofacial region with high fatality. Huanglianjiedu Decoction (HLJDD) is a well-known traditional Chinese medicinal prescription, which consists of Coptis chinensis Franch, Scutellaria baicalensis Georgi, Phellodendron amurense Rupr and Gardenia jasminoides J.Ellis. Some clinical studies showed HLJDD had good effectiveness on OSCC, but the mechanism is unclear.

Methods

In this study, potential components of HLJDD and putative targets were screened by Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Combining with potential targets of OSCC searched from Therapeutic Target Database (TTD) and Online Mendelian Inheritance in Man (OMIM), we drew protein–protein interaction (PPI) network by Cytoscape v3.2.0 software. After topological analysis we got core targets and further did Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Then we did the in vitro experiments to verify the major biological processes (cell cycle, apoptosis and proliferation) and signaling pathways (mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), protein kinase B (AKT)) on OSCC cell lines, SCC-25 and CAL-27.

Results

The potential component targets number of Coptis chinensis Franch, Scutellaria baicalensis Georgi, Phellodendron amurense Rupr and Gardenia jasminoides J.Ellis were 39, 93, 81and 88, respectively. Then we got 52 core targets which enriched in cell cycle, apoptosis, proliferation, MAPK activation etc. and obtained TOP30 pathways. On SCC-25 and CAL-27, HLJDD suppressed cell proliferation, induced late apoptosis and inhibited cell invasion and migration which were consistent with the results from network pharmacology analysis. Additionally, in cell cycle, we confirmed HLJDD inhibited G1 phase and arrested in S phase to reduce cell proliferation on SCC-25. In signaling pathways, HLJDD inhibited the phosphorylation of extracellular regulatory protein kinase 1/2 (ERK1/2) and NF-κB p65 (S468) on SCC-25 and CAL-27.

Conclusions

HLJDD played a potential therapeutic role on OSCC via inhibiting p-ERK1/2 and p-NF-κB p65 (S468).

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02201-6.

Modulating the ERK1/2-MMP1 Axis through Corosolic Acid Inhibits Metastasis of Human Oral Squamous Cell Carcinoma Cells

Corosolic acid (CA; 2α-hydroxyursolic acid) is a natural pentacyclic triterpenoid with antioxidant, antitumour and antimetastatic activities against various tumour cells during tumourigenesis. However, CA’s antitumour effect and functional roles on human oral squamous cell carcinoma (OSCC) cells are utterly unknown. In this study, our results demonstrated that CA significantly exerted an inhibitory effect on matrix metalloproteinase (MMP)1 expression, cell migration and invasion without influencing cell growth or the cell cycle of human OSCC cells. The critical role of MMP1 was confirmed using the GEPIA database and showed that patients have a high expression of MMP1 and have a shorter overall survival rate, confirmed on the Kaplan–Meier curve assay. In the synergistic inhibitory analysis, CA and siMMP1 co-treatment showed a synergically inhibitory influence on MMP1 expression and invasion of human OSCC cells. The ERK1/2 pathway plays an essential role in mediating tumour progression. We found that CA significantly inhibits the phosphorylation of ERK1/2 dose-dependently. The ERK1/2 pathway played an essential role in the CA-mediated downregulation of MMP1 expression and in invasive motility in human OSCC cells. These findings first demonstrated the inhibitory effects of CA on OSCC cells’ progression through inhibition of the ERK1/2–MMP1 axis. Therefore, CA might represent a novel strategy for treating OSCC.

Evaluation of anti-EGFR potential of quinazoline derivatives using molecular docking: An in silico approach

Overexpression of epidermal growth factor receptor (EGFR) is commonly reported in epithelial malignancies such as oral squamous cell carcinoma. Inhibition of EGFR is, therefore, considered a potential therapeutic strategy. Among various anti-EGFR drugs, quinazoline-based tyrosine kinase inhibitors (TKIs) have gained increasing attention. Present study focused to investigate anti-EGFR potential of quinazoline-based compounds using in silico approach. Two widely used docking programs GOLD and AutoDock Vina were used for the study. Four drugs were docked on the X-ray crystallographic EGFR structure (1XKK). GOLD and AutoDock Vina produced results in terms of fitness score and binding affinity, respectively. GOLD prioritized varlitinib and AutoDock Vina preferred imatinib over other drugs. To reach the consensus from both software, all four drugs coupled with EGFR were studied rigorously. GOLD demonstrated varlitinib to be the best inhibitor with highest fitness score of 109, whereas AutoDock Vina revealed imatinib as the potent ligand with least binding energy of -10.9 kcal/mol. Most stable hydrogen bonds observed by GOLD and maximum number of hydrophobic contacts along with strong ionic interaction exhibited by varlitinib through both software have led us to conclude varlitinib as the most potent EGFR inhibitor in the studied group.

Long non-coding RNA LINC01137 contributes to oral squamous cell carcinoma development and is negatively regulated by miR-22-3p

PURPOSE

Long noncoding RNAs (lncRNAs) are emerging as key regulators in cancer initiation and progression. LINC01137 is a recently identified lncRNA of which the functional role in the development of oral squamous cell carcinoma (OSCC) has not been determined yet.

METHODS

We analyzed the expression of LINC01137 using a microarray-based OSCC gene expression dataset (GSE31056), and validated the results obtained using RT-qPCR in 26 pairs of primary OSCC tumor tissues and adjacent non-tumor tissues. The proliferative and invasive effects of LINC01137 on OSCC cells were determined using CCK-8, colony formation and transwell assays, respectively. Targeted binding between miR-22-3p and LINC01137 was verified using a dual luciferase reporter assay.

RESULTS

We found that LINC01137 was significantly upregulated in primary OSCCs. LINC01137 knockdown inhibited OSCC cell proliferation, migration and invasion, whereas LINC01137 overexpression induced opposite effects. LINC01137 upregulation along with p53 inhibition enhanced the malignant transformation of oral cells. In addition, we found that miR-22-3p can directly target LINC01137 through interaction with a putative miR-22-3p-binding site present within the LINC01137 sequence. A significant negative correlation was observed between LINC01137 and miR-22-3p expression in primary OSCC specimens. Exogenous overexpression of miR-22-3p markedly reduced the endogenous expression level of LINC01137 in OSCC cells. Additional functional assays showed that miR-22-3p overexpression enhanced the inhibitory effect of siRNA-mediated LINC01137 silencing on OSCC cell proliferation, migration and invasion, whereas miR-22-3p inhibition had the opposite effect.

CONCLUSIONS

Our results indicate that LINC01137 functions as an oncogenic lncRNA in OSCC. miR-22-3p can directly target LINC01137 and negatively regulate its expression and function.

Downregulation of ceramide synthase 1 promotes oral cancer through endoplasmic reticulum stress

C18 ceramide plays an important role in the occurrence and development of oral squamous cell carcinoma. However, the function of ceramide synthase 1, a key enzyme in C18 ceramide synthesis, in oral squamous cell carcinoma is still unclear. The aim of our study was to investigate the relationship between ceramide synthase 1 and oral cancer. In this study, we found that the expression of ceramide synthase 1 was downregulated in oral cancer tissues and cell lines. In a mouse oral squamous cell carcinoma model induced by 4-nitroquinolin-1-oxide, ceramide synthase 1 knockout was associated with the severity of oral malignant transformation. Immunohistochemical studies showed significant upregulation of PCNA, MMP2, MMP9, and BCL2 expression and downregulation of BAX expression in the pathological hyperplastic area. In addition, ceramide synthase 1 knockdown promoted cell proliferation, migration, and invasion in vitro. Overexpression of CERS1 obtained the opposite effect. Ceramide synthase 1 knockdown caused endoplasmic reticulum stress and induced the VEGFA upregulation. Activating transcription factor 4 is responsible for ceramide synthase 1 knockdown caused VEGFA transcriptional upregulation. In addition, mild endoplasmic reticulum stress caused by ceramide synthase 1 knockdown could induce cisplatin resistance. Taken together, our study suggests that ceramide synthase 1 is downregulated in oral cancer and promotes the aggressiveness of oral squamous cell carcinoma and chemotherapeutic drug resistance.

Significance of the Overexpression of Substance P and Its Receptor NK-1R in Head and Neck Carcinogenesis: A Systematic Review and Meta-Analysis

The objective of our study has been, through a systematic review and meta-analysis, to increase the scientific evidence on the implications of SP and its receptor NK-1R in head and neck carcinogenesis. We searched studies published before May-2020 without date and publication language restrictions (PubMed, Embase, Web of Science, Scopus). We evaluated the quality of the studies included (QUIPS tool). We performed heterogeneity, sensitivity, small-study effects, and subgroup analyses. A total 16 studies and 1308 cases met inclusion criteria. Qualitative evaluation demonstrated that not all studies were performed with the same scientific rigor, finding the greatest risk of bias in the study confounding and prognostic factors measurement domains. Quantitative evaluation showed a greater SP/NK-1R overexpression in malignant head and neck lesions compared to benign lesions (p = 0.02), and that expression was observed in malignant salivary gland pathology. Likewise, we found a higher overexpression of NK-1R compared to SP (p = 0.02). In conclusion, the results of this systematic review and meta-analysis show evidence that the upregulation of SP and NK-1R are oncogenic events involved in head and neck carcinogenesis, probably acting in the early stages of malignization. In addition, there is evidence of a greater relevance of the upregulation of the NK-1R receptor compared to SP, which highlights the interest in deepening the development of targeted therapies on the receptor. Future studies assessing the relationships between SP/NK-1R among subjects with head and neck tumors could consider the recommendations given in this systematic review and meta-analysis to improve and standardize future research.

Interleukin-22 promotes the migration and invasion of oral squamous cell carcinoma cells

The roles of interleukin-22 (IL-22) in carcinogenesis have been proposed in various neoplasms. Increased expression of IL-22 has been observed in oral squamous cell carcinoma (OSCC) lesions as well as in other cancers. OSCC is still associated with poor prognosis and a high mortality rate because of its invasiveness and frequent lymph node metastasis. In the present study, we investigated the effects of IL-22 on OSCC cells. The human OSCC cell lines Ca9-22 and SAS were stimulated with IL-22 (1-10 ng/mL), and their migration abilities were examined using a cell scratch assay. A Matrigel invasion assay was performed to evaluate the invasion abilities of OSCC cells. Signal transducer and activator of transcription 3 (STAT3) phosphorylation, matrix metalloproteinase (MMP) and epithelial-mesenchymal transition (EMT)-related genes and proteins were also examined. IL-22 treatment promoted the migration and invasion abilities of OSCC cells without increasing their viability. IL-22 stimulation also induced STAT3 phosphorylation, MMP-9 activity and EMT-related genes and proteins. Our findings suggest that IL-22 has possible roles in the development of OSCC.

Clinicopathological and prognostic significance of PD-L1 in oral cancer: A preliminary retrospective immunohistochemistry study

OBJECTIVE

To evaluate the relation between PD-L1 expression in oral cavity squamous cell carcinomas and clinicopathological features as well as survival outcomes.

METHODS

A retrospective immunohistochemical study was carried out on 55 archived tumours from 55 patients. Tumours were stained for PD-L1 and scored by the proportion of tumour cells with positive membranous staining. PD-L1 scores were compared to the patient's clinicopathological characteristics for any significant associations. Kaplan-Meier curves were constructed for PD-L1 positive and negative tumours to investigate any advantage to survival.

RESULTS

Positive PD-L1 staining was found in 58% of tumours and was significantly more likely in non-smokers, non-drinkers and in tongue squamous cell carcinomas. Increased PD-L1 was also associated with increased lymphocyte infiltration as well as PD-L1 staining in lymphocytes and the epithelium adjacent to tumour invasion. No survival benefit was seen from PD-L1 expression in tumour cells.

CONCLUSIONS

PD-L1 expression is more common in non-smokers and non-drinkers, and its presence in the adjacent non-tumour epithelium suggests it may be involved in early oncogenesis.

Cancer stem cells: A comprehensive review on identification and therapeutic implications

Cancer stem cells (CSCs) are distinct subpopulations of tumor cells that possess the ability for perpetual self-renewal and proliferation. They produce downstream progenitor cells and cancer cells that drive tumor growth. Studies of many cancer types including oral squamous cell carcinoma (OSCC) have identified CSCs using specific markers, but it is still unclear as to where in the stem cell hierarchy these markers fall. This is compounded further by the presence of multiple CSC subtypes within OSCC, making investigation reliant on the use of multiple markers. This review paper focuses on the current knowledge in CSC markers including OCT4, SOX2, NANOG, aldehyde dehydrogenase 1, CD44, CD24, CD133 and Musashi-1, highlighting their use and validity in OSCC CSC research.

Loss of TIMP3 by promoter methylation of Sp1 binding site promotes oral cancer metastasis

The tissue inhibitor of metalloproteinase-3 (TIMP3) is the only member of the TIMP family that binds to the extracellular matrix and suppresses cancer cell growth, angiogenesis, migration, and invasion. However, whether the abnormal expression and promoter methylation of TIMP3 facilitates oral cancer metastasis remain unclear. In this study, the DNA methylation levels of TIMP3 CpG islands were assessed through pyrosequencing. Artificial modulation of TIMP3 was performed to explore the role of TIMP3 in tumor metastasis in vitro and in vivo. Our results showed that the suppression of TIMP3 transcription by DNA methylation involves the inhibition of the binding of the transcription factor Sp1 to the TIMP3 promoter as well as the upregulation of DNMT1 and DNMT3B. Functional analyses revealed that TIMP3 overexpression reduced migration and invasion abilities in oral cancer cells and inhibited lymph node metastasis in vivo. Moreover, TIMP3 regulated epithelial-mesenchymal transition by increasing the expression of the epithelial markers and reducing the expression of the mesenchymal markers. In conclusion, our findings suggested that the suppression of TIMP3 by DNA methylation contributes to oral cancer metastasis.

MUC1 gene silencing inhibits proliferation, invasion, and migration while promoting apoptosis of oral squamous cell carcinoma cells

The aim of the present study is to investigate the role of RNA interference in the inhibition of MUC1 gene expression in occurrence and metastasis of oral squamous cell carcinoma (OSCC) and its in-depth mechanisms. The OSCC and normal oral mucosa tissues, as well as normal oral epithelial cell line HOK and OSCC cell line SCC-4, Cal-27, TSCCA, Tca8113 were obtained to detect the expression of MUC1. Slug expression in OSCC and normal oral mucosa tissues was also determined. The OSCC cells were grouped to investigate the role of MUC1 gene silencing on proliferation, DNA replication, cell cycle distribution, apoptosis, colony formation ability, epithelial-mesenchymal transition (EMT), invasion, and migration of OSCC cells. We first found higher positive rate of MUC1 and Slug expression in OSCC tissues. Next, it was determined that higher expression of MUC1 was found in OSCC tissues and cells. Furthermore, silencing of MUC1 declined Slug expression, inhibited the proliferation, DNA replication, cell cycle progression, and EMT while inducing apoptosis of OSCC cells. Our study suggests that overexpression of MUC1 is found in OSCC, and MUC1 gene silencing could inhibit the proliferation, invasion, and migration while inducing apoptosis of OSCC cells.

Creation of Bone and Soft Tissue in Postmaxillectomy Patients Using Curvilinear Transport Distraction Osteogenesis

BACKGROUND

Large surgical defects in the maxilla due to trauma or tumor are usually reconstructed with revascularized-free fibula flaps (RFFF). In the past, the use of curvilinear transport distraction osteogenesis (CTDO) has been shown to be an efficacious way in closing large defects in the maxilla, but it had limitations which have now been overcome by the present development. The present distractor is an improvement upon the previous three prototypes and employs the concept of tetrafocal distraction by means of hybridizing the bone with the tooth in the transport disc segment. This article aims to prove that tetrafocal distraction provides a viable alternative to the RFFF.

MATERIALS AND METHOD

In a prospective cohort study of six postmaxillectomy patients, the method of CTDO was applied and investigated to ascertain the outcome. The regenerate bone was compared with the parent bone, using a new maxillary transport distractor. A linear bicortical fracture was created in the maxilla in a vertical direction (segmentally) to develop a mobile, vascularized transport disk. This transport disk underwent further subdivision to produce the concept of tetrafocal distraction.

RESULTS

After osseointegration of the dental implants, prosthetic rehabilitation of the dentition was successful. The authors report the successful outcome of two of the six cases subjected to CTDO to treat defects ranging from 25 mm (using bifocal distraction) to 80 mm along a curved trajectory (using tetrafocal distraction).

CONCLUSIONS

The production of curvilinear bone and soft tissue along a horizontal plane has been demonstrated. From a clinical perspective, the new alveolar bone achieved the correct width and height to create a physiological vestibule and an esthetic zone for dental implants. In addition, the shape of the palatal vault is also reconstituted. The tetrafocal method of the CTDO is a reliable method of maxillary reconstruction.

Assessment of the Blood Parameters, Cardiac and Liver Enzymes in Oral Squamous Cell Carcinoma Following Treated with Injectable Doxorubicin-Loaded Nano-Particles

Purpose:

Oral squamous cell carcinoma (OSCC) is the most common and most malignant disorder of the oral cavity. Standard cancer treatments have many complications for patients. Nausea, vomiting, and perturbation in blood cells are the most common side effects when using Doxorubicin (Dox) for the treatment of OSCC. Use of Doxorubicin-loaded nano-particles (n-Dox) give rise to increase its biological efficacy and the rapeutic effects. This study assessed the efficacy of the injectable form of the n-Doxon blood parameters and cardiac and liver enzymes compared to the commercial form of Dox in OSCC-induced by 4NQO in rats.

Methods:

4-nitroquinoline-1-oxideas was used as a solution in drinking water for inducing OSCC during 14 weeks in male Sprague-Dawley rats. Four groups of animals were categorized randomly: first (OSCC+Dox), second (OSCC+n-Dox), third (OSCC) and, last, healthy animals.

Results:

Using n-Dox had no harmful effect on the number of white and red blood cells. Thrombocytopenia and leukopenia in animals treated with n-Dox was less than the other groups. Hemoglobin and hematocrit in all treated groups did not differ and were similar to the healthy control. Hepatic and cardiac enzymes did not show any significant difference in any of the groups.

Conclusion:

The results of this research showed that significant decreases in haematological changes occurred, including leukopenia and anemia, in an animal model of OSCC induced by 4-NQO following use of n-Dox with compare to Dox. Use of n-Dox is better than of Dox for treatment of OSCC.

Amplification of the EGFR and CCND1 Are Coordinated and Play Important Roles in the Progression of Oral Squamous Cell Carcinomas

Oral squamous cell carcinoma (OSCC) is a common cancer in Taiwan and worldwide. To provide some clues for clinical management of OSCC, 72 advanced-stage OSCCs were analyzed using two microarray platforms (26 cases with Affymetrix 500 K and 46 cases with Affymetrix SNP 6.0). Genomic identification of significant targets in cancer analyses were used to identify significant copy number alterations (CNAs) using a q-value cutoff of 0.25. Among the several significant regions, 12 CNAs were common between these two platforms. Two gain regions contained the well-known oncogenes EGFR (7p11.2) and CCND1 (11q13.3) and several known cancer suppressor genes, such as FHIT (3p14.2-p12.1), FAT1 (4q35.1), CDKN2A (9p21.3), and ATM (11q22.3-q24.3), reside within the 10 deletion regions. Copy number gains of EGFR and CCND1 were further confirmed by fluorescence in situ hybridization and TaqMan CN assay, respectively, in 257 OSCC cases. Our results indicate that EGFR and CCND1 CNAs are significantly associated with clinical stage, tumor differentiation, and lymph node metastasis. Furthermore, EGFR and CCND1 CNAs have an additive effect on OSCC tumor progression. Thus, current genome-wide CNA analysis provides clues for future characterization of important oncogenes and tumor suppressor genes associated with the behaviors of the disease.

Mechanism for oral tumor cell lysyl oxidase like-2 in cancer development: synergy with PDGF-AB

Extracellular lysyl oxidases (LOX and LOXL1–LOXL4) are critical for collagen biosynthesis. LOXL2 is a marker of poor survival in oral squamous cell cancer. We investigated mechanisms by which tumor cell secreted LOXL2 targets proximal mesenchymal cells to enhance tumor growth and metastasis. This study identified the first molecular mechanism for LOXL2 in the promotion of cancer via its enzymatic modification of a non-collagenous substrate in the context of paracrine signaling between tumor cells and resident fibroblasts. The role and mechanism of active LOXL2 in promoting oral cancer was evaluated and employed a novel LOXL2 small molecule inhibitor, PSX-S1C, administered to immunodeficient, and syngeneic immunocompetent orthotopic oral cancer mouse models. Tumor growth, histopathology, and metastases were monitored. In vitro mechanistic studies with conditioned tumor cell medium treatment of normal human oral fibroblasts were carried out in the presence and absence of the LOXL2 inhibitor to identify signaling mechanisms promoted by LOXL2 activity. Inhibition of LOXL2 attenuated cancer growth and lymph node metastases in the orthotopic tongue mouse models. Immunohistochemistry data indicated that LOXL2 expression in and around tumors was decreased in mice treated with the inhibitor. Inhibition of LOXL2 activity by administration of PXS-S1C to mice reduced tumor cell proliferation, accompanied by changes in morphology and in the expression of epithelial to mesenchymal transition markers. In vitro studies identified PDGFRβ as a direct substrate for LOXL2, and indicated that LOXL2 and PDGF-AB together secreted by tumor cells optimally activated PDGFRβ in fibroblasts to promote proliferation and the tendency toward fibrosis via ERK activation, but not AKT. Optimal fibroblast proliferation in vitro required LOXL2 activity, while tumor cell proliferation did not. Thus, tumor cell-derived LOXL2 in the microenvironment directly targets neighboring resident cells to promote a permissive local niche, in addition to its known role in collagen maturation.

Experience of radiotherapy in head and neck

Abstract Objective: The aim of this manuscript was to understand and describe the experience of radiotherapy on the perspective of a woman with oral cancer. Methods: This is a qualitative, exploratory, descriptive study, with theoretical reference of medical anthropology and instrumental case study methodology. Data collection was performed in the oncology sector of a public university hospital in the Southeast region of Brazil, State of Minas Gerais, Brazil and at the participant’s residence, during from March to August, 2016. The case selected was of a female patient, diagnosed with Spinocellular Carcinoma in oral cavity, submitted to radiotherapy. Five semi-structured interviews and participant observation were performed and audio-taped. Results: Three thematic units are presented: the radiotherapy trajectory, family support and refuge in God and the importance of the multiprofessional team. The adverse reactions such as odynophagia, dysgeugia and weight loss were the ones that stood out the most, being causes of the social isolation of the participant, nonetheless the patient showed optimism and hope, despite the social isolation. Conclusion: The qualitative methodology allowed the whole trajectory of radiotherapy follow-up which made it possible to understand the treatment experience from the perspective of the participant. Despite the adverse reactions, no negative experience with radiotherapy was found. New studies using the qualitative methodology are suggested with groups presenting similar characteristics of the participant, thus providing a better understanding of the topic addressed, as well as the identification and adoption of strategies that aim at improving care and the quality of life of this population, as well.

Aberrant expression of vimentin predisposes oral premalignant lesion derived cells towards transformation

OBJECTIVE

We have previously reported the aberrant expression of vimentin in human oral premalignant lesions and a 4-Nitroquinoline 1-oxide (4NQO) model of rat lingual carcinogenesis. Hence, we wanted to understand whether the expression of vimentin in early stage contributes to the process of transformation.

STUDY DESIGN

Vimentin was stably expressed in oral premalignant lesion derived cells (vimentin negative) and various transformation related phenotypic assays were performed. Since vimentin alone failed to transform the cells, an additional carcinogenic stimulus benzo[a]pyrene (BP) was used. Concomitantly, immunohistochemistry (IHC) was performed on oral leukoplakia and tumor tissues for studying the expression of vimentin and E-cadherin.

RESULTS

Exogenous expression of vimentin led to the appearance of EMT and stemness-related signatures. Further, upon BP treatment, vimentin expressing clones showed an increase in vitro and in vivo transformation efficiency. Importantly, high vimentin-low E-cadherin expression significantly correlated with the grade of dysplasia, as also with the lymph node metastasis in oral tumors.

CONCLUSION

Our study suggests that the expression of vimentin in early stages may be beneficial, although not sufficient to achieve transformation. Further, high vimentin-low E-cadherin expression, if validated in more number of early oral lesions, may prove useful in the identification of high risk human premalignant lesions.

Epidemiological and Histopathological Aspects of Tongue Squamous Cell Carcinomas-Retrospective Study

Tongue squamous cell carcinoma is one of the most commonly diagnosed intraoral squamous cell carcinomas (25-40%), being considered an aggressive form of squamous cell carcinoma, as it is most commonly associated with lymph node metastases and the survival rate at five years is below 50%. In according with these data, we have proposed in this study to individualize an epidemiological and histopathological profile of the patients with such oral cancers, diagnosed and treated in the Oral and Maxillofacial Surgery Clinic and in the Otolaryngology Surgery Clinic of the Emergency Clinical County Hospital Craiova, between 2015-2017. The cases were histopathologically reassessed according to the latest WHO classification of head and neck tumors, the variables of interest being the age of the patients, the gender, the lesion topography, the histological subtype, the degree of tumor differentiation, the pTNM stage, the resection margin status and the Brandwein-Gensler prognostic score. Thus, we recorded an average age of 55.81±14.98 tongue cancer development, 65% of the casuistry being diagnosed during the 7th and 6th decades, with a slight prevalence in men, with development in two thirds of cases in the mobile portion of the tongue. Histopathologically, conventional forms of squamous cell carcinoma prevailed (53.7%), followed by varieties: acantholytic (26%), basaloid (13%), sarcomatoid (5.45%) and verrucous (1.85%). Moderate differentiated forms prevailed (44.44%), half of the cases falling within the moderate degree of Brandwein-Gensler's histological risk score and two thirds were diagnosed in pTNM stage II and III of the disease, and a quarter of the cases having the margins invaded.

Downregulation of miR-218-5p promotes invasion of oral squamous cell carcinoma cells via activation of CD44-ROCK signaling

The invasion front of oral squamous cell carcinoma (OSCC) harbors the most aggressive cells of the tumor and is critical for cancer invasion and metastasis. MicroRNAs (miRNAs) play important roles in OSCC progression. In this study, we modelled the OSCC invasion front on a microfluidic chip, and investigated differences in miRNA profiles between cells in the invasion front and those in the tumor mass by small RNA sequencing. We found that miR-218-5p was downregulated in invasion front cells and negatively regulates OSCC invasiveness by targeting the CD44-ROCK pathway. Thus, miR-218-5p may serve as a useful therapeutic target for OSCC. Moreover, invasion front cell isolation based-on microfluidic technology provided a useful strategy for cancer invasion study.

Effect of Ferula persica plant methanol extract on the level of Cox-2 in induced squamous cell carcinoma (SCC) in rat tongue

Background: More than 90% of oral cancers are cases of squamous cell carcinoma. Standard treatment of cancer includes a combination of surgery, chemotherapy and radiotherapy. Each of these treatments, however, brings about certain problems and side effects. Today herbal medicine, has become a more preferable option in dealing with health problems or preventing them because this type of medicine has better compatibility with the body and does not cause undesirable side effects. In this study , the effect of Ferula persica plant methanol extraction on Cox-2 levels in SCC induced rat tongue is conducted in vivo.

Methods: In this lab research, 75 rats from SD race in the age – range of 2/5 – 3 months were selected and put in five groups. In order to induce tongue carcinoma, 4– Nitroquinoline 1 (4 NQO) powder was used 3 times a week for each rat. Furthermore, Ferula persica extract was given to each of the groups in order to examine Cox-2 changes in the blood.

Results: Comparison of Cox-2 average in various groups resulted in the observation that there was significant difference between the Cox-2 levels in the groups which had only received carcinogen and the other groups. In this group, Cox-2 level was less and in the group that had received Ferula extract (500 mg) along with carcinogen , Cox-2 level was found to be more than other groups.

Conclusion: Ferula persica extract does not have reducing effect on serum Cox-2.

Prognostic and clinicopathological significance of cyclin D1 expression in oral squamous cell carcinoma: A systematic review and meta-analysis

OBJECTIVES

To evaluate the prognostic significance of cyclin D1 (CD1) overexpression in OSCC.

MATERIAL AND METHODS

We searched studies published before August 2017 (Pubmed, Embase, Web of Science, Scopus). We evaluated the quality of the studies included (Quality in Prognosis Studies [QUIPS] tool). The impact of CD1 overexpression on overall survival and disease-free survival, T status, N status, stage, and histological degree was meta-analyzed. We analyzed heterogeneity among studies, conducted sensitivity analyses, analyzed small-study effects, and conducted subgroup analyses.

RESULTS

31 studies (2942 patients) met inclusion criteria. Qualitative evaluation demonstrated that not all studies were performed with the same rigor, finding the greatest risk of bias in the study confounding domain. Quantitative evaluation showed that CD1 overexpression had a strong statistical association with worse overall survival (HR = 2.00, 95% CI = 1.59-2.51, p < 0.001), worse disease-free survival (HR = 1.46, 95% CI = 1.13-1.87, p = 0.003), higher T status (OR = 1.51, 95% CI = 1.07-2.13, p = 0.02), N+ status (OR = 2.16, 95% CI = 1.60-2.92, p < 0.001), advanced stage (OR = 1.44, 95% CI = 1.15-1.81, p = 0.002), and high histological grade (OR = 1.60, 95% CI = 1.12-2.29, p = 0.010). We observed heterogeneity in all parameters except for disease-free survival and clinical stage. We found effect of small studies on T and N status. The tonguel SCC subgroup showed the strongest association between CD1 overexpression and worse development. In addition, application of a cutoff point ≥10% tumor cells with nuclear CD1 expression maintained most of the significant associations reported.

CONCLUSIONS

These findings indicate that immunohistochemical assessment of CD1 overexpression may be useful as a prognostic biomarker for OSCC.

Perspectives on oral squamous cell carcinoma prevention-proliferation, position, progression and prediction

Squamous cell carcinoma arising from oral mucosal epithelium remains a lethal and deforming disease due to tumour invasion, oro-facial destruction, cervical lymph node metastasis and ultimate blood-borne dissemination. Worldwide, 300 000 new cases are seen each year, with a recent and significant rise in incidence affecting particularly the young. To rationalize perspectives on preventive strategies in oral cancer management, this study addresses a number of fundamental questions regarding carcinogenesis: proliferation-what epithelial cell changes precede tumour development? Position-why are certain oral sites so predisposed to cancer? Progression-why do some precursor lesions progress to invasive carcinoma and others do not? Prediction-how can we predict individual patient and/or lesion behaviour to prevent disease progression? By improving our understanding of oral carcinogenesis, can we thereby facilitate more effective primary, secondary and tertiary preventive strategies and ultimately reduce the global burden of oral squamous cell carcinoma (OSCC)?

uPA/uPAR and SERPINE1 in head and neck cancer: role in tumor resistance, metastasis, prognosis and therapy

There is strong evidence supporting the role of the plasminogen activator system in head and neck squamous cell carcinoma (HNSCC), particularly of its uPA (urokinase plasminogen activator) / uPAR (urokinase plasminogen activator receptor) and SERPINE1 components. Overexpression of uPA/uPAR and SERPINE1 enhances tumor cell migration and invasion and plays a key role in metastasis development, conferring poor prognosis. The apparent paradox of uPA/uPAR and its inhibitor SERPINE1 producing similar effects is solved by the identification of SERPINE1 activated signaling pathways independent of uPA inhibition. Both uPA/uPAR and SERPINE1 are directly linked to the induction of epithelial-to-mesenchymal transition, the acquisition of stem cell properties and resistance to antitumor agents. The aim of this review is to provide insight on the deregulation of these proteins in all these processes.

We also summarize their potential value as prognostic biomarkers or potential drug targets in HNSCC patients. Concomitant overexpression of uPA/uPAR and SERPINE1 is associated with a higher risk of metastasis and could be used to identify patients that would benefit from an adjuvant treatment. In the future, the specific inhibitors of uPA/uPAR and SERPINE1, which are still under development, could be used to design new therapeutic strategies in HNSCCs.

Ephrin-B2 reverse signaling regulates progression and lymph node metastasis of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignant tumor of the head and neck and frequently metastasizes to cervical lymph nodes. Aggressive local invasion and metastasis of OSCC are significant factors for poor prognosis. In this study, we investigated whether ephrin-B2 expressed in OSCC contributed to tumor progression and lymph node metastasis. Clinical specimens from patients with OSCC had robust ephrin-B2-positive tumor cells and ephrin-B2 protein level was associated with clinical stage, lymph node metastasis, and poor survival outcomes. We also determined that ephrin-B2 protein level was increased in OSCC cell lines compared to normal human oral keratinocytes and that its levels were associated with the migratory and invasive potential of OSCC cell lines. Transfection of an EFNB2-specific small interfering RNA (siRNA) into SAS-L1 cells significantly reduced proliferation, attachment, migration, and invasion through phosphorylation of the epidermal growth factor receptor, FAK, ERK1/2, p38, AKT, and JNK1/2 pathways. Furthermore, knockdown of EFNB2 significantly suppressed adhesion and transmigration of SAS-L1 cells toward human lymphatic endothelial cells. In addition, the growth rate of tumor xenografts and cervical lymph node metastases of OSCC were suppressed by local injection of EFNB2 siRNA. These results suggest that ephrin-B2 overexpression and activation of the ephrin-B2 reverse signaling pathway in tumor microenvironment in OSCC facilitates progression and lymph node metastasis via enhancement of malignant potential and interaction with surrounding cells.

Biomarkers in Tumorigenesis Using Cancer Cell Lines: A Systematic Review

Cancer is a leading cause of death worldwide. Despite many research advancements in the field, the genetic changes regulating the transformation of normal oral cells into malignant cells have not been fully elucidated. Several studies have evaluated carcinogenesis at the molecular level. Cancer cell lines are commonly used in biomedical research because they provide an unlimited source of cells and represent various stages of initiation and progression of carcinogenesis in vitro. Aims: The objective of the study was to review original research articles using cancer cell lines as a tool to understand carcinogenesis and to identify the genes involved in tumor development. Additionally, we also examined the application of the genes as predictive biomarkers. Methods and Materials: Several databases, including PubMed, Google Scholar, Ebsco, and Science Direct, were searched from 1985 to December 2016 using various combinations of the following key words: “mouth neoplasm”, “cell lines”, and “tumorigenesis”. Original experimental studies published in English were included. We excluded letters to the editor, historic reviews, and unpublished data from the analysis. Results: There were 17 studies (in vitro) included in the analysis. There were 14 genes and 4 miRNAs involved in malignant transformation of oral keratinocytes into cancer cells. The most commonly studied genes were p53, cyclin D1, and hTERT. Conclusion: Additional reviews and studies are needed to identify a panel of genes specific to various potentially malignant disorders and to aid in the early detection of oral squamous cell carcinoma (OSCC) because tumorigenesis involves the mutation of multiple genes. Furthermore, improving advanced cost-effective diagnostic methods may benefit the public health sector.

Study of trace metal imbalances in the blood, scalp hair and nails of oral cancer patients from Pakistan

Oral cancer is an important cause of cancer morbidity and mortality globally and exposure to trace metals alongside tobacco, alcohol and HPV are the important etiological factors in its development. Selected essential and toxic trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured in the blood, scalp hair and nails of oral cancer patients and counterpart controls by atomic absorption spectrometry. Mean concentrations of Cd, Ni and Pb were found to be significantly higher (p<0.05) and those of Cu, Fe and Zn were considerably lower in the blood, scalp hair and nails of the patients than the controls. Most of the metal concentrations exhibited higher dispersion and asymmetry in the blood, scalp hair and nails of the patients compared with the controls. The correlation study revealed significantly diverse relationships among the metals in blood, scalp hair and nails of both donor groups. Variations in the metal levels were also noted for various stages (I, II, III & IV) as well as the types (adenocarcinoma and squamous cell carcinoma) of oral cancer. Multivariate cluster analysis of the metal levels in the patients were also significantly dissimilar than the controls. The study evidenced considerably divergent variations in the metal levels in oral cancer patients in comparison with the controls.

Influence of the RPL34 gene on the growth and metastasis of oral squamous cell carcinoma cells

BACKGROUND

Oral squamous cell carcinoma (OSCC) accounts for almost 3% of all malignant tumors all over the world. This study aims to investigate the correlation of RPL34 with the cell growth and metastasis of oral squamous cell carcinoma (OSCC) as well as its clinical prognosis.

METHOD

Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry were conducted to determine the RPL34 expression in 85 OSCC tissues and 30 normal oral mucosa tissues. Besides, OSCC cell lines SCC-4 were divided into blank group, negative control (NC) group and RPL34-shRNA group. The qRT-PCR and western blot were performed to measure RPL34 expression, CCK-8 and flow cytometry to observe cell growth and apoptosis, and wound healing and transwell to detect cell migration and invasion.

RESULTS

The RPL34 gene expression was up-regulated in OSCC tissues and cells. The RPL34 expression was significantly correlated with differentiation degree, TNM stage and lymph node metastasis. Patients with positive RPL34 expression had a poorer prognosis. After inhibition of RPL34 expression, the proliferation of SCC-4 cells was slowed down at 24h, 48h, 72h and 96h respectively, and both the migration distance and the number of invasive cells were reduced, while there was an increase in the ratio of cells at G0/G1 stage and cell apoptosis.

CONCLUSION

The RPL34 gene was highly expressed in OSCC, while silencing RPL34 could block cell proliferation and metastasis, but promote cell apoptosis, suggesting the RPL34 gene to be a new promising clinical target for OSCC therapy.

Cancer Stem Cells in Oral Cavity Squamous Cell Carcinoma: A Review

Cancer stem cells (CSCs) have been identified in oral cavity squamous cell carcinoma (OCSCC). CSCs possess the ability for perpetual self-renewal and proliferation, producing downstream progenitor cells and cancer cells that drive tumor growth. Studies of many cancer types including OCSCC have identified CSCs using specific markers, but it is still unclear as to where in the stem cell hierarchy these markers fall. This is compounded further by the presence of multiple CSC subtypes within OCSCC, making investigation reliant on the use of multiple markers. This review examines the current knowledge in CSC markers OCT4, SOX2, NANOG, ALDH1, phosphorylated STAT3, CD44, CD24, CD133, and Musashi-1, specifically focusing on their use and validity in OCSCC CSC research and how they may be organized into the CSC hierarchy. OCSCC CSCs also express components of the renin–angiotensin system (RAS), which suggests CSCs may be novel therapeutic targets by modulation of the RAS using existing medications.

Association between BRCA1 P871L polymorphism and cancer risk: evidence from a meta-analysis

Breast cancer 1 (BRCA1) gene makes great contributions to the repair of DNA. The association between BRCA1 P871L polymorphism and cancer risk has been investigated in a growing number of studies, but the conclusions are not conclusive. To obtain a comprehensive conclusion, we performed a meta-analysis of 24 studies with 13762 cases and 22388 controls. The pooled results indicated that BRCA1 gene P871L variant decreased risk of overall cancer (homozygous model: odds ratio (OR) = 0.89, 95%confidence interval (CI) = 0.79-1.00; recessive model: OR = 0.89, 95% CI = 0.80-0.99). The stratified analysis observed decreased risk associated with BRCA1 P871L in subgroups among Asians and high score studies, but not Caucasians or low score studies. In conclusion, despite several limitations, this meta-analysis suggested that BRCA1 P871L genetic variation may be associated with decreased susceptibility to cancer.

Inhibition of αvβ3 integrin induces loss of cell directionality of oral squamous carcinoma cells (OSCC)

The connective tissue formed by extracellular matrix (ECM) rich in fibronectin and collagen consists a barrier that cancer cells have to overpass to reach blood vessels and then a metastatic site. Cell adhesion to fibronectin is mediated by α_vβ₃ and α₅β₁ integrins through an RGD motif present in this ECM protein, thus making these receptors key targets for cell migration studies. Here we investigated the effect of an RGD disintegrin, DisBa-01, on the migration of human fibroblasts (BJ) and oral squamous cancer cells (OSCC, SCC25) on a fibronectin-rich environment. Time-lapse images were acquired on fibronectin-coated glass-bottomed dishes. Migration speed and directionality analysis indicated that OSCC cells, but not fibroblasts, showed significant decrease in both parameters in the presence of DisBa-01 (1μM and 2μM). Integrin expression levels of the α₅, α_v and β₃ subunits were similar in both cell lines, while β1 subunit is present in lower levels on the cancer cells. Next, we examined whether the effects of DisBa-01 were related to changes in adhesion properties by using paxillin immunostaining and total internal reflection fluorescence TIRF microscopy. OSCCs in the presence of DisBa-01 showed increased adhesion sizes and number of maturing adhesion. The same parameters were analyzed usingβ3-GFP overexpressing cells and showed that β3 overexpression restored cell migration velocity and the number of maturing adhesion that were altered by DisBa-01. Surface plasmon resonance analysis showed that DisBa-01 has 100x higher affinity for α_vβ₃ integrin than forα5β1 integrin. In conclusion, our results suggest that the α_vβ₃ integrin is the main receptor involved in cell directionality and its blockage may be an interesting alternative against metastasis.

Integrative analysis to select cancer candidate biomarkers to targeted validation

Targeted proteomics has flourished as the method of choice for prospecting for and validating potential candidate biomarkers in many diseases. However, challenges still remain due to the lack of standardized routines that can prioritize a limited number of proteins to be further validated in human samples. To help researchers identify candidate biomarkers that best characterize their samples under study, a well-designed integrative analysis pipeline, comprising MS-based discovery, feature selection methods, clustering techniques, bioinformatic analyses and targeted approaches was performed using discovery-based proteomic data from the secretomes of three classes of human cell lines (carcinoma, melanoma and non-cancerous). Three feature selection algorithms, namely, Beta-binomial, Nearest Shrunken Centroids (NSC), and Support Vector Machine-Recursive Features Elimination (SVM-RFE), indicated a panel of 137 candidate biomarkers for carcinoma and 271 for melanoma, which were differentially abundant between the tumor classes. We further tested the strength of the pipeline in selecting candidate biomarkers by immunoblotting, human tissue microarrays, label-free targeted MS and functional experiments. In conclusion, the proposed integrative analysis was able to pre-qualify and prioritize candidate biomarkers from discovery-based proteomics to targeted MS.

Association of microRNA polymorphisms with the risk of head and neck squamous cell carcinoma in a Chinese population: a case-control study

BACKGROUND

MicroRNA (miRNA) polymorphisms may alter miRNA-related processes, and they likely contribute to cancer susceptibility. Various studies have investigated the associations between genetic variants in several key miRNAs and the risk of human cancers; however, few studies have focused on head and neck squamous cell carcinoma (HNSCC) risk. This study aimed to evaluate the associations between several key miRNA polymorphisms and HNSCC risk in a Chinese population.

METHODS

In this study, we genotyped five common single-nucleotide polymorphisms (SNPs) in several key miRNAs (miR-149 rs2292832, miR-146a rs2910164, miR-605 rs2043556, miR-608 rs4919510, and miR-196a2 rs11614913) and evaluated the associations between these SNPs and HNSCC risk according to cancer site with a case-control study including 576 cases and 1552 controls, which were matched by age and sex in a Chinese population.

RESULTS

The results revealed that miR-605 rs2043556 [dominant model: adjusted odds ratio (OR) 0.71, 95% confidence interval (CI) 0.58-0.88; additive model: adjusted OR 0.74, 95% CI 0.62-0.89] and miR-196a2 rs11614913 (dominant model: adjusted OR 1.36, 95% CI 1.08-1.72; additive model: adjusted OR 1.28, 95% CI 1.10-1.48) were significantly associated with the risk of oral squamous cell carcinoma (OSCC). Furthermore, when these two loci were evaluated together based on the number of putative risk alleles (rs2043556 A and rs11614913 G), a significant locus-dosage effect was noted on the risk of OSCC (P trend < 0.001). However, no significant association was detected between the other three SNPs (miR-149 rs2292832, miR-146a rs2910164, and miR-608 rs4919510) and HNSCC risk.

CONCLUSION

Our study provided the evidence that miR-605 rs2043556 and miR-196a2 rs11614913 may have an impact on genetic susceptibility to OSCC in Chinese population.

Optical diagnosis of actinic cheilitis by infrared spectroscopy

Actinic cheilitis (AC) is considered a potentially malignant disorder of the lip. Biomolecular markers study is important to understand malignant transformation into squamous cell carcinoma. Fourier transform infra red (FT-IR) spectroscopy was used to analyze AC in this study.

OBJECTIVES

The aim of the study was to evaluate if FT-IR spectral regions of nucleic acids and collagen can help in early diagnosis of malignant transformation.

METHODS

Tissues biopsies of 14 patients diagnosed with AC and 14 normal tissues were obtained. FT-IR spectra were measured at five different points resulting in 70 spectra of each. Analysis of Principal components analysis (PCA) and linear discrimination analysis (LDA) model were also used. In order to verify the statistical difference in the spectra, Mann-Whitney U test was performed in each variable (wavenumber) with p-value <0.05.

RESULTS

After the Mann-Whitney U test the vibrational modes of CO (Collagen 1), PO2 (Nucleic Acids) and CO asymmetric (Triglycerides/Lipids) were observed as a possible spectral biomarker. These bands were chosen because they represent the vibrational modes related to collagen and DNA, which are supposed to be changed in AC samples. Based on the PCA-LDA results, the predictive model corresponding to the area under the curve was 0.91 for the fingerprint region and 0.83 for the high wavenumber region, showing the greater accuracy of the test.

CONCLUSIONS

FT-IR changes in collagen and nucleic acids could be used as molecular biomarkers for malignant transformation.

Apple- and Hop-Polyphenols Inhibit Porphyromonas gingivalis-Mediated Precursor of Matrix Metalloproteinase-9 Activation and Invasion of Oral Squamous Cell Carcinoma Cells

BACKGROUND

Recent epidemiologic studies have revealed a significant association between periodontitis and oral squamous cell carcinoma (OSCC). Furthermore, periodontitis is markedly associated with orodigestive cancer mortality, whereas Porphyromonas gingivalis (Pg) infection has been identified as a specific and potentially independent microbial factor related to increased risk of orodigestive cancer death. The authors previously reported that Pg induced the precursor form of matrix metalloproteinase-9 (proMMP-9) production via proteinase-activated receptor (PAR)-related pathways, after which proMMP-9 was activated by gingipains to enhance cellular invasion of SAS cells. In the present study, effects of selected polyphenols as inhibitors of cellular invasion caused by Pg gingipains in SAS cells are examined.

METHODS

OSCC cells were infected with Pg strains including gingipain mutants. To evaluate effects of inhibitors: 1) apple polyphenol (AP); 2) hop bract polyphenol (HBP); 3) high-molecular-weight fractions of HBP (HMW-HBP); 4) low-molecular-weight fractions of HBP (LMW-HBP); 5) epigallocatechin gallate (EGCg); 6) KYT-1 (Arg-gingipain inhibitor); and KYT-36 (Lys-gingipain inhibitor) in combination are used. PAR2 and PAR4 mRNA expressions are examined using real-time reverse transcription polymerase chain reaction, and signaling pathways are evaluated by western blotting analysis.

RESULTS

KYT-1/KYT-36, AP, HBP, and HMW-HBP significantly inhibited PAR2 and PAR4 mRNA expressions, proMMP-9 activation, and cellular invasion. Furthermore, AP, HBP, and HMW-HBP reduced activation of heat shock protein 27 and Ets1 and nuclear translocation of nuclear factor-kappa B, whereas EGCg and LMW-HBP did not.

CONCLUSION

These results suggest that AP, HBP, HMW-HBP are potent inhibitors of proMMP-9 activation and cellular invasion mediated with Pg in OSCC cells.