Diabetes may increase risk for oral cancer through the insulin receptor substrate-1 and focal adhesion kinase pathway

EGFR and HER-2 oncogenes expression in an experimental model of two-stage chemically induced carcinogenesis in mouse skin

The aim of the study was to investigate the expression of EGFR and HER-2 oncogenes using an experimental two stage chemically induced carcinogenesis protocol on the dorsal skin in FVB/N mice. Forty female FVB/N mice 4 weeks old, were grouped into one control (n = 8) and two experimental groups (Group A: n = 16, Group B: n = 16) following a randomization process. Two-stage carcinogenesis protocol, was implicated, including an initial treatment with 97.4 nmol DMBA on their shaved dorsal skin and subsequent treatments of 32.4 nmol TPA applications after 13 weeks for Group A and after 20 weeks for Group B. The control group C, received no treatment. Skin was examined weekly for tumor development. Post-experiment, animals were euthanized for tissue analysis. The histological status of the skin lesions in the experimental groups corresponded well with tumour advancement (from dysplasia to poorly-differentiated carcinoma). Tumour sections were evaluated histologically and immunohistochemically. EGFR expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 008 respectively), while tended to be higher in benign tumours (p = 079), compared to normal histology. Moreover, mean percentage of EGFR positive expression in malignant tumours was significantly higher than in benign tumours (p < 001). HER-2 expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 015 respectively), while tended to be higher in benign tumours (p = 085), compared to normal histology. Furthermore, mean percentage of HER-2 positive expression in malignant tumours was significantly higher than in benign tumours (p = 005). The study demonstrated that in FVB/N mice subjected to a two-stage chemically induced carcinogenesis protocol, there was a significant increase in the expression of EGFR and HER-2 oncogenes in precancerous and malignant skin lesions compared to normal tissue. This suggests a potentially early role of these oncogenes in the progression of skin tumours in this model.

Dentists Behavioral Factors Influencing Early Detection of Oral Cancer: Direct Clinical Observational Study

This study aimed to investigate the possible factors affecting dentists' behavior relating to performing oral cancer examinations as part of routine clinical examination. A total of 95 direct clinical observation sessions-utilizing an instrument consisting of 19 evidence-based observational criteria for oral cancer examinations-were observed by four calibrated dentists. Thirty-two final-year students, 32 interns, and 31 faculty members of Jazan Dental School were examined between April 9 and May 4, 2017. A descriptive analysis was conducted to investigate the frequencies/percentages of the performed observing criteria by all examiners. ANOVA and Tukey tests were carried out to investigate the difference between the examiner groups. A total number of 32 patients participated in the study, whereby each patient was examined by three different examiners from each group, as well as by the attending observer/s. Fewer than 50% of the examiners performed the clinical steps necessary for an oral cancer examination-for example, taking into account past medical history, as well as extra and intra-oral examinations. More than 90% of the examiners examined hard tissue, whereas fewer than 30% of them educated their patients about possible risk factors. A significant difference between examiner groups was found in favor of faculty members. A gap between knowledge and actual practice of oral cancer examinations was evident: majority of participants failed to perform the necessary steps for an oral cancer examination. Previous experience and confidence in performing oral cancer examination are possible explanations for the dentist's behavior toward oral cancer examination.

Impact of hyperglycemia on the expression of GLUT1 during oral carcinogenesis in rats

BACKGROUND

On the background of the epidemiological link between diabetes and oral cancer, the present study aimed to analyze the potential involvement of selected glucose transporters (GLUT1/GLUT3/GLUT4), if any, in such putative association.

METHODS AND RESULTS

Oral carcinogenesis was induced by 4-nitroquinoline N-oxide in 10 non-diabetic and 10 diabetic rats; 8 non-diabetic and 7 diabetic rats served as controls. Expressions of selected GLUTs at mRNA and protein levels were analyzed in oral tissue (normal/lesion) by quantitative real-time PCR and immunohistochemistry respectively. Premalignant lesions (hyperplasia/dysplasia/carcinoma-in-situ) appeared on tongues of carcinogen-treated animals. Significant increase of GLUT1mRNA level was seen from normal to lesion tongues, along increasing lesion grades (from hyperplasia/mild dysplasia to moderate/severe dysplasia) and in lesions induced under hyperglycemic condition than that induced under normoglycemic one; a similar trend was found in transcript variant-1 of GLUT1, but not in variant-2. GLUT3 and GLUT4 mRNA levels were comparable among lesions irrespective of grades and glycemic status. Concordant to mRNA level, overall expression of GLUT1 protein was higher in tongue lesions in presence of hyperglycemia than in absence of such condition; non-lesion portions of tongues exposed to carcinogen showed a similar trend. Moreover in carcinogen-treated groups, non-lesion and lesion portions of tongues under hyperglycemic condition showed predominantly membranous expression for GLUT1 which was again significantly higher than equivalent portions of tongue under normoglycemic condition.

CONCLUSION

Hyperglycemia seemed to favor GLUT1 over-expression and membrane localization of the protein during oral carcinogenesis. GLUT1 transcript variant-1 appeared to be more important than variant-2 in disease pathogenesis.

Identification of potential candidate genes for lip and oral cavity cancer using network analysis

Lip and oral cavity cancer, which can occur in any part of the mouth, is the 11th most common type of cancer worldwide. The major obstacles to patients' survival are the poor prognosis, lack of specific biomarkers, and expensive therapeutic alternatives. This study aimed to identify the main genes and pathways associated with lip and oral cavity carcinoma using network analysis and to analyze its molecular mechanism and prognostic significance further. In this study, 472 genes causing lip and oral cavity carcinoma were retrieved from the DisGeNET database. A protein-protein interaction network was developed for network analysis using the STRING database. VEGFA, IL6, MAPK3, INS, TNF, MAPK8, MMP9, CXCL8, EGF, and PTGS2 were recognized as network hub genes using the maximum clique centrality algorithm available in cytoHubba, and nine potential drug candidates (ranibizumab, siltuximab, sulindac, pomalidomide, dexrazoxane, endostatin, pamidronic acid, cetuximab, and apricoxib) for lip and oral cavity cancer were identified from the DGIdb database. Gene enrichment analysis was also performed to identify the gene ontology categorization of cellular components, biological processes, molecular functions, and biological pathways. The genes identified in this study could furnish a new understanding of the underlying molecular mechanisms of carcinogenesis and provide more reliable biomarkers for early diagnosis, prognostication, and treatment of lip and oral cavity cancer.

Role of Focal Adhesion Kinase in Head and Neck Squamous Cell Carcinoma and Its Therapeutic Prospect

Head and neck cancers are one of the most prevalent cancers globally. Among them, head and neck squamous cell carcinoma (HNSCC) accounts for approximately 90% of head and neck cancers, which occurs in the oral cavity, oral pharynx, hypopharynx and larynx. The 5-year survival rate of HNSCC patients is only 63%, mainly because about 80–90% of patients with advanced HNSCC tend to suffer from local recurrence or even distant metastasis. Despite the more in-depth understanding of the molecular mechanisms underlying the occurrence and progression of HNSCC in recent years, effective targeted therapies are unavailable for HNSCC, which emphasize the urgent demand for studies in this area. Focal adhesion kinase (FAK) is an intracellular non-receptor tyrosine kinase that contributes to oncogenesis and tumor progression by its significant function in cell survival, proliferation, adhesion, invasion and migration. In addition, FAK exerts an effect on the tumor microenvironment, epithelial–mesenchymal transition, radiation (chemotherapy) resistance, tumor stem cells and regulation of inflammatory factors. Moreover, the overexpression and activation of FAK are detected in multiple types of tumors, including HNSCC. FAK inhibition can induce cell cycle arrest and apoptosis, significantly decrease cell growth, invasion and migration in HNSCC cell lines. In this article, we mainly review the research progress of FAK in the occurrence, development and metastasis of HNSCC, and put forward the prospects for the therapeutic targets of HNSCC.

Evaluation of factors associated with the risk stratification of survivorship for stage IV squamous cell carcinoma of the oral cavity: A 10-year retrospective study

BACKGROUND

Oral squamous cell carcinoma (OSCC) leads to thousands of deaths every year in Taiwan. Nearly 40% of OSCC patients are diagnosed with stage IV disease, which has a poor prognosis. Multimodality treatments including surgery and adjuvant therapy have been utilized, but their treatment outcomes are generally poor. In this study, we sought to identify possible clinical impact factors that may contribute to the survival of stage IV OSCC.

METHODS

Data for patients with malignant neoplasms of the oral cavity registered in the Cancer Registry Database of Taipei Veterans General Hospital between 2002 and 2011 were retrieved. The study patients consisted of OSCC patients with clinical stage IV disease who had undergone a surgery and adjuvant therapy. The primary endpoints were the 5-year disease-free survival (DFS) and overall survival (OS) rates. The clinicopathological characteristics of the patients were also stratified and compared.

RESULTS

A total of 191 OSCC patients were included for retrospective analysis. The different subgroups of stage IV disease presented different treatment outcomes. The 5-year OS versus DFS rates of each subgroup were as follows: T4N0: 70.9% versus 52.6%; T1-3N23: 66.1% versus 49.8%; T4N1: 49.6% versus 31.6%; and T4N23: 40.9% versus 31.0% (p < 0.01). Patients with diabetes, moderate or poor cell differentiation, perineural invasion, and extracapsular spread presented lower 5-year OS rates (hazard ratio [HR] = 1.87, 1.65, 2.42, and 2.14, respectively), and patients with perineural invasion, positive cut margin, and extracapsular spread presented lower 5-year DFS rates (HR = 1.57, 1.62, and 1.71, respectively).

CONCLUSION

In this study, we elucidated the different survival rates of different subgroups of stage IV OSCC following the same treatment scheme. The results of the study provide clinical physicians with references by which to evaluate prognosis and determine post-operative disease monitoring timetables based upon different characteristics.

The Impact of Type II Diabetes on Tongue Dysplasia and p16-Related Aging Process: An Experimental Study

Objective

To evaluate the effect of streptozotocin-induced experimental diabetes mellitus on p16, p53, Ki67, and Bcl2 expressions and histopathological changes in the tongue of the rats.

Material and Methods

Twenty-two adult female Sprague-Dawley rats were used. The rats were randomly divided into 2 groups (n = 14) as control (C) (n = 8) and diabetic (DM) (n = 6). The rats in the DM group were given streptozotocin as a single intraperitoneal dose for induction of diabetes. Histopathological and immunohistochemical evaluations of formalin-fixed and paraffin-embedded tissue sections of the tongue were used.

Results

Significant differences were observed between the DM group and the control group in terms of epithelial thickness, length of filiform papillae, and width of filiform papillae (p = 0.005, p = 0.001, and p = 0.006, respectively). There was no significant difference between the groups in terms of mononuclear inflammatory cell infiltration, capillary proliferation, and dysplasia (p = 0.204, p = 0.244, and p = 0.204, respectively). As a result of immunohistochemical studies, no significant difference was found between the groups in terms of p53, Ki67, and Bcl-2 expressions (p = 0.588, p = 0.662, and p = 0.686, respectively). A significant difference was found between the groups when p16 expression was evaluated (p = 0.006).

Conclusions

In our study, streptozotocin-induced experimental diabetes mellitus induced p16 expression but did not show any difference in p53, Bcl-2, and Ki67 levels. It should be considered in the studies that the pathological changes at the early stages of the relationship between DM and oral cancer may be related to p16 expression; however, it may also be linked with p16-related aging process.

Targeting Cellular Metabolism Modulates Head and Neck Oncogenesis

Considering the great energy and biomass demand for cell survival, cancer cells exhibit unique metabolic signatures compared to normal cells. Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent neoplasms worldwide. Recent findings have shown that environmental challenges, as well as intrinsic metabolic manipulations, could modulate HNSCC experimentally and serve as clinic prognostic indicators, suggesting that a better understanding of dynamic metabolic changes during HNSCC development could be of great benefit for developing adjuvant anti-cancer schemes other than conventional therapies. However, the following questions are still poorly understood: (i) how does metabolic reprogramming occur during HNSCC development? (ii) how does the tumorous milieu contribute to HNSCC tumourigenesis? and (iii) at the molecular level, how do various metabolic cues interact with each other to control the oncogenicity and therapeutic sensitivity of HNSCC? In this review article, the regulatory roles of different metabolic pathways in HNSCC and its microenvironment in controlling the malignancy are therefore discussed in the hope of providing a systemic overview regarding what we knew and how cancer metabolism could be translated for the development of anti-cancer therapeutic reagents.

Association of Periodontitis with Oral Cancer: A Case-Control Study

The association between oral squamous cell carcinoma (OSCC) and periodontitis in large hospital cases with cohort controls has yet to be evaluated. The aim of this study was to investigate the association of periodontitis with OSCC across tumor location and tumor-node-metastasis (TNM) stage among Koreans ( N = 424). OSCC cases ( n = 146) were recruited from Seoul National University Dental Hospital and matched by age, sex, and smoking to controls ( n = 278) from the Yangpyeong health and periodontal cohort in Korea. OSCC was diagnosed through biopsy and radiographs, including computed tomography and magnetic resonance imaging. Tumor location and TNM stage were classified after the surgery. Periodontitis was defined by alveolar bone loss with panoramic radiographs following the guidelines of the Fifth European Workshop in Periodontology. Alcohol intake, education, physical activity, obesity by body mass index, hypertension by blood pressure, diabetes by plasma glucose, and hypercholesterolemia by plasma cholesterol were considered as confounders. Information about age, sex, smoking, alcohol intake, education, and physical activity was obtained through interview; body mass index and blood pressure, through physical examination; and preoperative glucose and cholesterol, through laboratory tests. Bivariate analysis was applied with Fisher’s exact chi-square test. Multivariable conditional logistic regression models were applied to evaluate the adjusted association of periodontitis with OSCC after controlling for confounders. Subgroup analyses were explored by OSCC and periodontitis. Participants with periodontitis were 3.7 times more likely to have OSCC (adjusted odds ratio [aOR] = 3.66, 95% CI = 1.46 to 9.23) than participants without periodontitis. The differences in periodontitis were not statistically significant across TNM stages of OSCC ( P > 0.05) and its location ( P > 0.05). The link was highlighted among males (aOR = 6.55), elders aged >60 y (aOR = 4.98), and those with more tooth loss (aOR = 9.99). Our data showed that periodontitis was independently associated with OSCC. Thus, the risk of OSCC could be modulated by reducing periodontitis.

Identification of human papillomavirus status specific biomarker in head and neck cancer

BACKGROUND

In an attempt to improve the prognosis of patients with head and neck cancer, it could be necessary to identify biomarkers in homogeneous subgroups of patients with head and neck cancer.

METHODS

We explored the necessity of human papillomavirus (HPV) status-specific biomarkers in patients with head and neck cancer and identified an HPV status-specific gene set. The identified gene set was validated with the external microarray datasets. For this purpose, we used 4 microarray datasets obtained from a public database. One dataset was used for identifying the HPV status specific gene set, and the other datasets were used for validation.

RESULTS

The identified gene set for distinguishing head and neck cancer from head and neck normal, did not accurately discriminate the HPV specific patients with head and neck cancer from the head and neck normal group. Also, it was demonstrated that some HPV-positive (HPV+) head and neck cancer-specific genes may not be significant in HPV-negative (HPV-) head and neck cancer patients. The identified HPV specific gene sets showed good performance in validation datasets. The HPV+ head and neck cancer-specific gene set included various metabolism-related pathways, and the HPV- head and neck cancer-specific gene set included several pathways; fibroblast, collagen degradation, actin-binding, and actin cytoskeleton.

CONCLUSION

The identification of HPV status-specific significant gene set was necessary. It is expected that HPV status-specific biomarkers can be helpful in deciding therapeutic methods for patients with head and neck cancer, after biological validation and large prospective trials.

Histologic and systemic prognosticators for local control and survival in margin-negative transoral laser microsurgery treated oral cavity squamous cell carcinoma

BACKGROUND

Appreciable local recurrence rates observed in patients with margin-negative, transoral laser microsurgery (TLM)-treated oral cavity squamous cell carcinoma (SCC) necessitate identification of new prognosticators for local control and survival. A histopathologic index (Brandwein-Gensler score [BGS]) and intrinsic/iatrogenic/chronic conditions causing immune compromise are investigated.

METHODS

From a prospectively assembled database of TLM-treated oral cavity SCC, specimens for 60 patients with a minimum of 2-years follow-up could undergo BGS assignment. Local control, disease-specific survival (DSS), and overall survival (OS) were study endpoints.

RESULTS

"Low-BGS" was recorded in 28 patients (47%) and "high-BGS" in 32 patients (53%), whereas immune compromise was observed in 18%. In multivariate analyses, immune compromise was the only predictor for local control. T classification and immune compromise were prognostic for DSS and OS. "High-BGS" was prognostic only for OS.

CONCLUSION

"High-BGS" was associated with recurrences but immune compromise was the most significant predictor of local control and survival in margin-negative, TLM-treated oral cavity SCC. Strategies that maintain/restore tumor-specific immune responses in immune compromised oral cavity SCC hosts need to be developed.

miR-370 modulates insulin receptor substrate-1 expression and inhibits the tumor phenotypes of oral carcinoma

BACKGROUND

MicroRNAs play important roles in carcinogenesis. A preliminary screening study suggested that down-regulation of miR-370 occurs in oral squamous cell carcinoma (OSCC) tissue. Insulin receptor substratre-1 (IRS-1) is the substrate of insulin-like growth factor receptor (IGFR), which modulates AKT/mTOR activation in malignancies. The relationship between miR-370 and IRS-1, and their functional roles in OSCC pathogenesis are unclear.

MATERIALS AND METHODS

Primary OSCC specimens were examined for miR-370 expression. Exogenous expression of miR-370 was established using both stable subclones and transient expression, and these were used to gain insights into miR-370's functions in OSCC cells. Knockdown of miR-370 and IRS-1 was also carried out in OSCC cells using a small interference oligonucleotide approach.

RESULTS

Squamous cell carcinoma tissues with perineural invasion had lowered miR-370 expression compared with contrasting OSCC. OSCC cells also exhibited lower miR-370 expression than normal oral keratinocytes, and this can be reversed by treatment with 5-aza-2'-deoxycytidine. Exogenous miR-370 expression decreases the migration and anchorage-independent growth of OSCC cells, which implies a suppressor role for miR-370. The enhancement of anchorage-independent growth of OSCC cells through miR-370 inhibiting can be reduced by knockdown of IRS-1 expression.

CONCLUSION

This study concludes that miR-370 is able to target IRS-1 for oral tumorigenesis.

The prevalence of median rhomboid glossitis in diabetic patients: a case-control study

BACKGROUND

Diabetes mellitus (DM) is one of the most common disorders of endocrine glands which has a worldwide distribution and is a risk factor for oral pathology so; the purpose of the present study was to investigate the association between median rhomboid glossitis (MRG) and DM.

METHODS

We examined 202 Iranian patients with DM aged 10-86 years and 261 healthy subjects aged 10-28 years and the diagnosis of MRG was made based on clinical features.

RESULTS

The examination indicated that 13 (6.43%) diabetic patients and 4 (1.53%) of control group had MRG.There was a significant difference in the prevalence of MRG, between patients and control group. MRG showed no association with other variables (age, sex, duration of DM, drugs, FBS, A1C).

CONCLUSION

In the present study the prevalence of MRG in diabetics was much higher than that of controls.

Impact of diabetes mellitus on the prognosis of patients with oral squamous cell carcinoma: a retrospective cohort study

BACKGROUND

Diabetes mellitus (DM) is a prevalent chronic metabolic disease reported to affect the treatment outcomes of malignancies. This study explores the impact of diabetes on the prognosis of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Clinicopathological characteristics and survival in terms of overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival (CSS) of patients with OSCC who underwent surgical intervention at the Taipei Veterans General Hospital between 2002 and 2005 were stratified by diabetic status and compared.

RESULTS

Patients with DM tend to have a lower OS, RFS, and CSS compared with nondiabetics (adjusted hazard ratio [HR] = 2.22, 2.42, and 2.16, respectively) even in less aggressive tumor stages (stage I and II). In advanced tumors, diabetic patients who were not prescribed adjuvant therapy had a significantly higher recurrence rate than nondiabetic patients (HR = 2.66). However, there was no significant difference in treatment outcome in patients with locally advanced tumors amenable to receive adjuvant therapy, even with the delayed initiation of adjuvant therapy in the DM group (49.1 +/- 22.3 days vs. 40.0 +/- 16.6 days, P = .04). DM was also associated with a higher frequency of perineural invasion (adjusted odds ratio [OR] = 2.53).

CONCLUSION

DM status could be a prognostic factor for OSCC, particularly for its effect in the survival and perineural invasion. Although diabetes-associated comorbidities may impair decision making toward less aggressive therapeutic modality, adjuvant treatment may be essential for DM patients to improve their survival.

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

This paper provides a synopsis of the main papers on epidemiology, diagnosis and prognosis of oral and oropharyngeal squamous cell carcinoma (OSCC) and head and neck SCC (HNSCC) published in 2007 in Oral Oncology - an international interdisciplinary journal which publishes high quality original research, clinical trials and review articles, and all other scientific articles relating to the aetiopathogenesis, epidemiology, prevention, clinical features, diagnosis, treatment and management of patients with neoplasms in the head and neck, and orofacial disease in patients with malignant disease.

Diabetes enhances cell proliferation but not Bax/Bcl-2-mediated apoptosis during oral oncogenesis

Markers of cell proliferation (Ki-67 antigen) and apoptosis (Bax, Bcl-2) were studied in an experimental model of chemically induced carcinogenesis in normal and diabetic (type I) Sprague-Dawley rats. Thirteen diabetic and 12 normal rats developed cancer after 4-nitroquinoline-N-oxide treatment, while 6 diabetic and 6 normal animals were used as controls. The biopsies were classified pathologically (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma) and studied immunohistochemically using monoclonal antibodies against Bax, Bcl-2 and Ki-67 proteins. The Bcl-2/Bax ratio was almost stable during the oncogenesis process in the diabetic rats, whereas the normal rats showed an increased Bcl-2/Bax ratio during the stage of moderately differentiated carcinoma. In contrast, Ki-67 expression was higher in diabetic rats than in normal ones in almost all stages of oral oncogenesis, and it reached significantly increased levels in the stages of normal control tissue, dysplasia and moderately differentiated squamous cell carcinoma. These data suggest that diabetes results in increased cell proliferation during oral oncogenesis, but this is accomplished without affecting the Bax/Bcl-2-mediated apoptotic pathways.

Enhancement of erbB2 and erbB3 expression during oral oncogenesis in diabetic rats

PURPOSE

The expression of erbB2 and erbB3 receptors was investigated in an experimental model of chemically induced oral carcinogenesis in normal and diabetic (type I) Sprague-Dawley rats.

METHODS

Thirteen diabetic and twelve normal rats developed precancerous and cancerous lesions after 4-nitroquinoline-N-oxide treatment, while six diabetic and six normal animals were used as controls. Sections of biopsies from all animals were classified histologically in the following categories: normal mucosa, hyperplasia, dysplasia, early invasion, well- and moderately-differentiated squamous cell carcinoma. Each section was studied immunohistochemically using monoclonal antibodies against erbB2 and erbB3 proteins and six representative histological regions in each section were analysed.

RESULTS

The erbB2 was expressed at very low levels in normal rats, while in diabetic animals its expression was significantly increased during early invasion (P = 0.04). The erbB3 expression was significantly elevated in well-differentiated carcinoma in normal animals (P = 0.01), while in diabetic animals it was significantly increased during oral mucosal hyperplasia and dysplasia (P = 0.03 and 0.0007, respectively). The comparison of erbB2 expression between diabetic and normal rats revealed significant differences in all stages except for the tumor stage of moderately differentiated carcinoma (P = 0.01, 0.00001, 0.00001, 0.003, and 0.00001). In regard to erbB3 expression, significant differences between diabetic and normal rats existed only in normal, non-cancerous and precancerous stages (P = 0.007, 0.0001, 0.0003).

CONCLUSIONS

It seems that diabetes enhances the expression of both erbB2 and erbB3 in certain stages of oral oncogenesis possibly resulting in promotion of cell proliferation and inhibition of apoptosis.