Dietary habits, oral impact on daily performance and type 2 diabetes: a matched case-control study from Sudan.

BACKGROUND: It is evident that social and behavioural factors influence on individuals' general health and quality of life. Nevertheless, information about the influence of dietary habits on oral health-related quality of life is limited; especially among patients with type 2 diabetes (T2D). The aim of this study was to examine the influence of dietary habits and clinical oral health indicators on oral health-related quality of life in individuals with and without T2D. METHODS: A total of 149 T2D cases and 298 controls were recruited for this age and gender matched case-control study. Questionnaire-guided interviews were conducted to collect data about socio-demographic characteristics, consumption of food items per week (milk, meat, eggs, vegetables, fruits, sweets and bread) and oral impact on daily performance (OIDP). Plaque index, bleeding on probing, probing depth, tooth mobility, decayed, missing and filled teeth index (DMFT) and root caries were recorded. RESULTS: Difficulty with eating and sleeping were more frequently reported by T2D cases (23.5% and 16.1%, respectively) than by the controls (10.7% and 5.0%, respectively) (P < 0.01). After adjusting for diabetic status, plaque index, bleeding on probing, probing depth, tooth mobility, root caries, and missing teeth, those with high consumption of milk and sweets, were more likely than those with low consumption to report any oral impact (OIDP > 0). The corresponding ORs were 1.23 (1.01-4.89) and 2.10 (1.08-4.09), respectively. Participants with low consumption of meat and vegetables were more likely than their counterparts with high consumption to report any oral impact. The corresponding ORs were 0.46 (0.25-0.83) and 0.38 (0.17-0.87), respectively. There was a significant interaction between diabetic status and meat consumption as well as between diabetic status and bread consumption. CONCLUSIONS: Oral impacts were more frequently reported in T2D cases than controls. Independent of diabetic- and oral clinical status, dietary habits discriminated between individuals with and without oral impacts. The influence of meat and bread consumption on OIDP varied significantly according to T2D status.

Influence of type 2 diabetes on local production of inflammatory molecules in adults with and without chronic periodontitis: a cross-sectional study.

BACKGROUND: Pathological changes in periodontal tissues are mediated by the interaction between microorganisms and the host immune-inflammatory response. Hyperglycemia may interfere with this process. The aim of this study was to compare the levels of 27 inflammatory molecules in the gingival crevicular fluid (GCF) of patients with type 2 diabetes, with and without chronic periodontitis, and of chronic periodontitis subjects without diabetes. A putative correlation between glycated haemoglobin (HbA1c) and levels of the inflammatory molecules was also investigated. METHODS: The study population comprised a total of 108 individuals, stratified into: 54 with type 2 diabetes and chronic periodontitis (DM + CP), 30 with chronic periodontitis (CP) and 24 with type 2 diabetes (DM). Participants were interviewed with the aid of structured questionnaire. Periodontal parameters (dental plaque, bleeding on probing and periodontal pocket depth) were recorded. The GCF levels of the 27 inflammatory molecules were measured using multiplex micro-bead immunoassay. A glycated haemoglobin (HbA1c) test was performed for patients with diabetes by boronate affinity chromatography. RESULTS: After adjustment for potential confounders, the DM + CP group had higher levels of IL-8 and MIP-1ß, and lower levels of TNF-α, IL-4, INF-γ, RANTES and IL-7 compared to the CP group. Moreover, the DM + CP group had lower levels of IL-6, IL-7 and G-CSF compared to the DM group. The DM group had higher levels of IL-10, VEGF, and G-CSF compared to the CP group. The levels of MIP-1α and FGF were lower in diabetes patients (regardless of their periodontal status) than in chronic periodontitis subjects without diabetes. Diabetes patients (DM + CP and DM) had higher Th-2/Th-1 ratio compared to the CP group. HbA1c correlated positively with the pro-inflammatory cytokines (Pearson correlation coefficient = 0.27, P value: 0.02). CONCLUSION: Type 2 diabetes and chronic periodontitis may influence the GCF levels of inflammatory molecules synergistically as well as independently. Type 2 diabetes was associated with high Th-2/Th-1 ratio, and modulated the local expression of molecules involved in the anti-inflammatory and healing processes.

Impact of Chronic Periodontitis on Levels of Glucoregulatory Biomarkers in Gingival Crevicular Fluid of Adults with and without Type 2 Diabetes.

The relationship between diabetes and periodontal disease is bidirectional, but information about the effect of chronic periodontitis on the levels of the glucoregulatory biomarkers locally in gingival crevicular fluid (GCF) is limited. The aim of this study was to compare the levels of 10 glucoregulatory biomarkers in GCF, firstly in subjects with type 2 diabetes (T2DM) presenting with and without chronic periodontitis and secondly, in subjects without diabetes, with and without chronic periodontitis. The material comprised a total of 152 subjects, stratified as: 54 with T2DM and chronic periodontitis (G1), 24 with T2DM (G2), 30 with chronic periodontitis (G3) and 44 without T2DM or periodontitis (G4). The levels of the biomarkers were measured using multiplex biometric immunoassays. Periodontal pocket depths were recorded in mm. Subsets G1 and G2 and subsets G3 and G4 were compared independently. Among T2DM subjects, GIP, GLP-1 and glucagon were significantly up-regulated in G1 compared to G2. Moreover, there were no statistical differences between the two groups regarding C-peptide, insulin, ghrelin, leptin and PAI-1. Comparisons among individuals without T2DM revealed significantly lower amounts of C-peptide and ghrelin in G3 than in G4. The number of sites with pocket depth ≥ 4mm correlated negatively with C-peptide (Spearman's correlation co-efficient: -0.240, P < 0.01) and positively with GIP and visfatin (Spearman's correlation co-efficient: 0.255 and 0.241, respectively, P < 0.01). The results demonstrate that chronic periodontitis adversely influences the GCF levels of glucoregulatory biomarkers, as it is associated with disturbed levels of biomarkers related to the onset of T2DM and its medical complications.

Comparison between single PCR and nested PCR in detection of human papilloma viruses in paraffin-embedded OSCC and fresh oral mucosa.

BACKGROUND: Infection with human papilloma virus (HPV) has been implicated as one of the risk factors for the development of oropharyngeal cancer. Many different HPV tests exist, and information regarding their specific technical, analytical, and clinical properties is increasing. AIM: This study aimed to compare the level of detection of HPV using two reliable polymerase chain reaction (PCR) methods, nested PCR (NPCR) and single PCR (SPCR), in archival paraffin-embedded oral squamous cell carcinoma (OSCC) samples and fresh oral mucosa specimens. MATERIALS AND METHODS: The presence of HPV genome in two groups of tissue samples was analyzed: (i) 57 paraffin-embedded OSCC samples from Sudan and (ii) eight healthy fresh oral mucosal samples from Swedish volunteers. The specimens were tested by SPCR with primer pair MY9/MY11 and NPCR using GP5+/GP6+ primer sets. RESULTS: Eighteen (32%) out of the 57 paraffin-embedded OSCC samples, and five (62%) out of the eight fresh clinically healthy samples were found to be HPV-positive with NPCR. With SPCR, four (7%) out of the paraffin-embedded OSCC samples were HPV-positive. A statistically significant difference between HPV-positive and -negative samples was found when comparing NPCR and SPCR in OSCC and fresh oral mucosa (p<0.0001). The comparative test between SPCR and NPCR showed 100% sensitivity and 69% specificity for OSCC. CONCLUSION: The use of the GP5+/GP6+ nested PCR increased the positivity rate, efficiency rate and sensitivity of HPV detection in oral samples significantly and should be considered as the method of choice.

Profiling of chromosomal changes in potentially malignant and malignant oral mucosal lesions from South and South-East Asia using array-comparative genomic hybridization.

BACKGROUND/AIM: Using array-CGH, the present study aimed to explore genome-wide profiles of chromosomal aberrations in samples of oral cancer (OC), oral submucous fibrosis (OSF) and their corresponding normal oral mucosa from Indian (n=18) and OC from Sri Lankan (n=12) patients with history of BQ use, and correlate the findings to other clinicopathological parameters. A second aim was to verify the results from the array-CGH by selecting a candidate gene, S100A14, and examine its expression and genetic polymorphisms by immunohistochemistry (IHC) and restriction fragment length polymorphism (RFLP) using samples from both populations and from multi-national archival DNA and paraffin-embedded samples of OC. RESULTS: In OC and OSF samples, 80 chromosomal regions (harboring 349 genes) were found as deleted or amplified. Out of the 349 genes, 34 (including several S100 gene family members) were found to be deleted and 30 (containing NOTCH4, TP53 and ERBB2) were found as amplified in OSF and OC cases. 285 genes (including TP53, ERBB2 and BRCA1) were found either as deleted in one population or amplified in the other. Few chromosomal alterations were found to be exclusive to either OC or OSF samples alone. IHC demonstrated down-regulation and transfer of S100A14 protein expression from membrane to cytoplasmic. RFLP showed differential distribution between Asian samples compared to African and Western samples at 461 G>A SNP. CONCLUSION: The present study provides findings on chromosomal aberrations likely to be involved in pathogenesis of OC and OSF. Findings of chromosomal changes harboring genes previously found in OC examined from Western, African and Asian populations demonstrate the importance of these changes in development of OC, and the existence of common gene-specific amplifications/deletions, regardless of source of samples or attributed risk factors. We report a down-regulation of S100A14 expression to be a significant marker in association with loss of 1q21 in 70% of OC samples.

Association between oral health status and type 2 diabetes mellitus among Sudanese adults: a matched case-control study.

AIM: The purpose of this study was to compare the clinical and subjective oral health indicators of type 2 diabetic patients (T2DM) with age and gender matched non-diabetic controls. A second aim was to identify clinical and subjective oral health indicators that discriminate between well-controlled and poorly controlled T2DM patients as well as between patients with long and short duration of the disease. METHODS: A total of 457 individuals participated in the study (154 T2DM cases and 303 non-diabetic controls). The T2DM group was sub-divided according to metabolic control [(well-controlled: glycosylated haemoglobin test 8%), (poorly controlled: glycosylated haemoglobin test > 8%)] and according to duration of T2DM [(long duration: >10 years), (short duration: 10 years)]. Participants were interviewed using a structured questionnaire including socio-demographics, lifestyle and oral health related quality of life factors. The clinical examination comprised full mouth probing depths, plaque index, tooth mobility index, furcation involvement and coronal and root surface caries. RESULTS: The T2DM patients presented with more probing depths 4 mm, furcation involvement, tooth mobility, missing teeth, and oral impacts on daily performance (OIDP). The corresponding adjusted odds ratios and their 95% confidence intervals were 4.07 (1.74-9.49), 2.96 (1.36-6.45), 5.90 (2.26-15.39), 0.23 (0.08-0.63) and 3.46 (1.61-7.42), respectively. Moreover, the odds ratio was 2.60 (1.21-5.55) for the poorly controlled T2DM patients to have high levels of mobility index and 2.94 (1.24-6.94) for those with long duration of T2DM to have high decayed, missed and filled teeth (DMFT) values. CONCLUSION: This study revealed that chronic periodontitis, tooth mobility, furcation involvement and OIDP were more prevalent among T2DM patients compared to their non-diabetic controls.

S100A14 interacts with S100A16 and regulates its expression in human cancer cells.

Both S100A14 and S100A16 are members of the multifunctional S100 protein family. Formation of homo/heterodimers is considered to be one of the major mechanisms for S100 proteins to execute their diverse cellular functions. By employing a classical Yeast two hybrid (Y-2 H) screen, we identified S100A16 as the single interaction partner of S100A14. This interaction was verified by co-immunoprecipitation, double indirect immunofluorescence and double immunostaining in specimens of oral squamous cell carcinoma and normal oral mucosa. The functional significance of this interaction was examined by employing retroviral mediated over-expression and knock-down of these proteins in several cancer cell-lines. Over-expression and knock-down of S100A14 led to concomitant up- and down-regulation of S100A16 protein in the cell-lines examined. However, there was no up-regulation of S100A16 mRNA upon S100A14 over-expression, indicating that modulation of S100A16 expression was not due to enhanced transcriptional activity but possibly by post-transcriptional regulation. In contrary, over-expression of S100A16 was associated neither with the up-regulation of S100A14 mRNA nor its protein, suggesting a unidirectional regulation between S100A14 and S100A16. Cellular treatment with protein synthesis inhibitor cycloheximide demonstrated a time-dependent intracellular degradation of both S100A16 and S100A14 proteins. Additionally, regulation of S100A16 and S100A14 degradation was found to be independent of the classical proteasomal and lysosomal pathways of protein degradation. Further studies will therefore be necessary to understand the functional significance of this interaction and the mechanisms on how S100A14 is involved in the regulation of S100A16 expression.

p53 Codon 72 polymorphism in oral exfoliated cells in a Sudanese population.

Earlier studies have investigated the tumor suppressor gene p53 as a co-factor in the development of oral squamous cell carcinoma (OSCC). Our previous studies have indicated that chronic use of Sudanese snuff (toombak) and the presence of human papilloma virus (HPV) may be involved in the high prevalence of OSCC in Sudan. This study investigated the prevalence of p53 codon 72 polymorphism in brush biopsies obtained from a Sudanese population. A total of 174 individuals were included in the study; chronic toombak users (n=152) and non-users (n=22). DNA was extracted from all the samples and genotyped for the codon 72 polymorphism by polymerase chain reaction/restriction fragment length polymorphism. The Arg/Pro genotype was found in 53% of the 174 study participants, compared to 21% found with Arg/Arg and 26% found with Pro/Pro. Stratifying by toombak use, 28 (18%), 45 (29%) and 79 (52%) of the 152 samples from toombak users had Arg/Arg, Pro/Pro and Arg/Pro respectively, compared to 9 (41%), 0 (0%) and 13 (59%) found in the 22 samples from non users. The differences between the samples from toombak users and non users in Arg/Arg and Pro/Pro codon 72 polymorphism and HPV infection were statistically significant (p<0.05). Our study indicated that a high prevalence of the genotype Arg/Pro at the p53 codon 72 may contribute to susceptibility to OSCC, especially in combination with the use of carcinogenic tobacco-specific nitrosamine (TSNA)-rich toombak. Our observations warrant an in-depth study for understanding the role of p53 polymorphism in human oral cancers.

Human papilloma virus, herpes simplex virus and epstein barr virus in oral squamous cell carcinoma from eight different countries.

Oral squamous cell carcinoma (OSCC) is a major health problem in many parts of the world, and the major causative agents are thought to be the use of alcohol and tobacco. Oncogenic viruses have also been suggested to be involved in OSCC development. This study investigated the prevalence of human papillomaviruses (HPV), herpes simplex virus (HSV) and Epstein-Barr virus (EBV) in 155 OSCC from eight different countries from different ethnic groups, continents and with different socioeconomic backgrounds. 41 A total of OSCCs were diagnosed in the tongue (26%) and 23 in the floor of the mouth (15%); the other 91 OSCCs were diagnosed in other locations (59%). The patients were also investigated regarding the use of alcohol and smoking and smokeless tobacco habits. Tissue samples were obtained from formalin-fixed, paraffin-embedded samples of the OSCC. DNA was extracted and the viral genome was examined by single, nested and semi-nested PCR assays. Sequencing of double-stranded DNA from the PCR product was carried out. Following sequencing of the HPV-, HSV- and EBV-positive PCR products, 100% homology between the sampels was found. Of all the 155 OSCCs examined, 85 (55%) were positive for EBV, 54 (35%) for HPV and 24 (15%) for HSV. The highest prevalence of HPV was seen in Sudan (65%), while HSV (55%) and EBV (80%) were most prevalent in the UK. In 34% (52/155) of all the samples examined, co-infection by two (46/155=30%) or three (6/155=4%) virus specimens was detected. The most frequent double infection was HPV with EBV in 21% (32/155) of all OSCCs. There was a statistically significant higher proportion of samples with HSV (p=0.026) and EBV (p=0.015) in industrialized countries (Sweden, Norway, UK and USA) as compared to developing countries (Sudan, India, Sri Lanka and Yemen). Furthermore, there was a statistically significant higher co-infection of HSV and EBV in samples from industrialized countries (p=0.00031). No firm conclusions could be drawn regarding the relationship between alcohol, tobacco and virus infections. The significance of our findings must be put in relation to other risk factors and these observations warrant further studies to determine the possible role of viral infections and co-infections with HPV, EBV and HSV as risk markers for the development of OSCC.

S100A14 inhibits proliferation of oral carcinoma derived cells through G1-arrest.

Altered expression of S100A14 has been reported in various human cancers including oral squamous cell carcinomas (OSCCs). Its biological functions in carcinogenesis, however, are largely unknown. This study aimed to investigate the functional role of S100A14 in tumor cell proliferation and its possible functional association with p53. S100A14 protein was found to be gradually down-regulated during the transition from normal to dysplastic and carcinoma cells in an in vitro human OSCC progression model. When over-expressed by employing retroviral expression vector, S100A14 inhibited proliferation of CaLH3 and OSCC1, OSCC cell-lines harboring wild type (wt) p53, by inducing G1-arrest. This G1-arrest correlated with up-regulation of p21 both in the CaLH3 and OSCC1 cell-lines. shRNA mediated silencing of p53 led to partial suppression of p21 in S100A14 over-expressing CaLH3 cells, indicating that p21 up-regulation was, at least, partly dependent on p53. We further demonstrated that nuclear accumulation of p53 occurred with over-expression of S100A14 in CaLH3 cells. Our data suggest a novel role of S100A14 in OSCC cell proliferation by inducing G1-arrest and also indicate a functional link between S100A14 and the tumor suppressor protein p53.

Differential expression of apoptosis, cell cycle regulation and intermediate filament genes in oral squamous cell carcinomas associated with toombak use in Sudan.

Previously we used microarray genomic hybridization technology to explore genome-wide profiles of chromosomal aberrations in samples of oral squamous cell carcinomas (OSCCs) and paired normal controls. Based on these findings, 9 genes related to apoptosis, cell cycle regulation and intermediate filament proteins were selected and their differential expression status was examined by real-time quantitative RT-PCR in 26 samples of Sudanese OSCCs and their matched normal controls. The findings were correlated with the habit of toombak use. The mRNA levels of Bcl2, keratin 1, keratin 13 and p53 were significantly lower and the level of survivin was significantly higher in the OSCC samples of the toombak users compared to their paired control samples. A significant down-regulation in keratin 1 and keratin 13 expression levels was found in the OSCC samples of the nontoombak users compared to their normal control samples. The differential expression of genes related to apoptosis, cell cycle regulation and types I and II keratin could be useful diagnostic markers and provide valuable information for the understanding of oral malignancy in relation to toombak use.

Global gene expression profile of osteoblast-like cells grown on polyester copolymer scaffolds.

One of the principal goals in tissue engineering is to produce scaffold materials that will guide cells to differentiate and regenerate functional replacement tissue at the site of injury. Poly(l-lactide-co-1,5-dioxepan-2-one) [Poly(LLA-co-DXO)], a potential scaffolding material for bone tissue engineering, has high hydrophilicity. Previous in vitro studies using human osteoblast-like cells (HOBs) demonstrated greater cytocompatibility and enhanced osteogenic differentiation when HOBs were seeded onto Poly(LLA-co-DXO) compared to Poly(l-lactide) [P(LLA)] scaffolds. The aim of the study was to identify the gene expression profiles of HOBs obtained from alveolar bone and grown on Poly(LLA-co-DXO) biodegradable polymer scaffolds compared to P(LLA) one. Illumina HumanWG-6 v3.0 Expression BeadChips were used for the gene expression analysis. Several genes were found as differentially expressed at 24 h and at 21 days. Expression of genes related to cell adhesion, cytoskeleton, antiapoptosis, proliferation, and bone mineralization was influenced by adding the monomer 1,5-dioxepan-2-one to the L-lactide. Genes related to three biological pathways involving Integrin, Notch, and Ras were found to be upregulated. For selected genes, results were confirmed by quantitative reverse transcriptase-polymerase chain reaction. Further, calcium content analysis revealed a significant enhancement of calcium deposition on both tested scaffolds. This observation was confirmed by Von Kossa and Alizarin Red S staining. Findings of this study are relevant to a better understanding of the molecular mechanisms underlying the behavior of HOBs in bone regenerative procedure.

Pathophysiology of oral cancer in experimental animal models: a review with focus on the role of sympathetic nerves.

Global increase in incidence and mortality as well as poor prognosis of oral cancer (OC) has intensified efforts towards early detection and prevention of this disfiguring disease. Several studies have been conducted using experimental animal models to understand the pathophysiology and molecular events involved in OC. Lack of identification of specific biomarkers during the multifaceted steps of oral carcinogenesis has hindered its diagnosis and treatment. Solid stress generated by growing tumors as well as abnormalities in tumor vasculature lead to increased interstitial fluid pressure, which could obstruct therapeutic drug delivery to tumors. Furthermore, the sympathetic nervous system is known to affect angiogenesis, vessel permeability, immune responses and carcinogenesis. Recent findings indicate that, in addition to angiogenic and lymphangiogenic factors, tumor cells release neurotrophic factors that initiate innervation. Interactions between cytokines and sympathetic neurotransmitters, and their respective receptors expressed by the nerve, immune and tumor cells appear to influence tumor growth. Thus, understanding the complex signaling processes and interrelationships between vascular, nervous and immune systems during oral carcinogenesis may prove vital for successful prevention and treatment of OC. This review aims at outlining the available knowledge on pathophysiology of OC in experimental animal models including evidence from our own findings.

S100A14 regulates the invasive potential of oral squamous cell carcinoma derived cell-lines in vitro by modulating expression of matrix metalloproteinases, MMP1 and MMP9.

Despite the differential expression of S100A14 (a newly identified S100 member) in various human cancers including oral squamous cell carcinomas (OSCCs), its biological role in tumour invasion has not been characterised. The aim of this study was thus to investigate the possible role of S100A14 in OSCC cell invasion. Using immunohistochemistry in normal (n=13), dysplastic (n=10) and OSCC (n=16) archival tissues, S100A14 protein was found to be down-regulated/lost with concomitant membrane to cytoplasmic translocation in OSCCs, especially in the invading tumour islands. These expression data were corroborated by profiling S100A14 mRNA expression using quantitative RT-PCR (qRT-PCR) in an in vitro human OSCC progression model consisting of cell-lines derived from normal (n=3), dysplastic (n=3) and OSCC (n=8) tissues. Employing in vitro Matrigel invasion assay, we demonstrated that retroviral vector mediated over-expression of S100A14 resulted in significant decrease in the invasive potential of OSCC derived CaLH3 and H357 cell-lines whereas siRNA mediated knockdown resulted in significant increase in the invasive potential of CaLH3 cell-line. Pathway focused PCR array and validation using qRT-PCR revealed that S100A14 over-expression was associated with down-regulation of MMP1 and MMP9 mRNAs in both CaLH3 and H357 cell-lines. Further, S100A14 over-expression was found to be associated with suppression of MMP9 gelatinolytic activity in CaLH3 cell-line. Additionally, an inverse correlation between mRNA expression levels of MMP1 and MMP9 with S100A14 was found in 19 cases of OSCCs. Collectively, these data provide the first evidence for a role of S100A14 protein in regulation of OSCC cell invasion by modulating expression of MMP1 and MMP9.

Presence of human papilloma virus, herpes simplex virus and Epstein-Barr virus DNA in oral biopsies from Sudanese patients with regard to toombak use.

Using PCR/DNA sequencing, we investigated the prevalence of human papillomavirus (HPV), herpes simplex virus (HSV) and Epstein-Barr virus (EBV) DNA in brush biopsies obtained from 150 users of Sudanese snuff (toombak) and 25 non-users of toombak in formalin-fixed paraffin-embedded tissue samples obtained from 31 patients with oral dysplasias (25 toombak users and 6 non-users), and from 217 patients with oral cancers (145 toombak users and 72 non-users). In the brush tissue samples from toombak users, HPV was detected in 60 (40%), HSV in 44 (29%) and EBV in 97 (65%) of the samples. The corresponding figures for the 25 samples from non-users were 17 (68%) positive for HPV, 6 (24%) positive for HSV and 21 (84%) for EBV. The formalin-fixed samples with oral dysplasias were all negative for HPV. In the 145 oral cancer samples from toombak users, HPV was detected in 39 (27%), HSV in 15 (10%) and EBV in 53 (37%) of the samples. The corresponding figures for the samples from non-users were 15 (21%) positive for HPV, 5 (7%) for HSV and 16 (22%) for EBV. These findings illustrate that prevalence of HSV, HPV and EBV infections are common and may influence oral health and cancer development. It is not obvious that cancer risk is increased in infected toombak users. These observations warrant further studies involving toombak-associated oral lesions, to uncover the possible mechanisms of these viral infections in the development of oral cancer, and the influence of toombak on these viruses.

Gene expression analysis by cDNA microarray in oral cancers from two Western populations.

BACKGROUND: In this work, gene expression profile was examined in 19 cases of oral cancer (OC) obtained from patients from Sweden (n=8) and UK (n=11) and the findings were tested for correlation to patient's clinicopathological data. MATERIALS AND METHODS: Following total RNA extraction, cDNA synthesis, labeling with fluorescent dyes and hybridization to the 21 k human oligonucleotide microarrays, slides were scanned and images were subjected to Genepix and J-Express analysis. Results for selected genes were validated by quantitative reverse transcriptase polymerase chain reaction (Q-RT-PCR). RESULTS: 42 genes were identified as being differentially expressed. These included 39 genes of known functions (such as fatty acid synthase (FASN), 5' nucleotidase, ecto (NT5E), high mobility group AT-hook (HMGA1), and v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS)) and 3 novel genes; 26 (67%) of the 39 genes with known functions were previously reported in oral/head and neck tumors examined from other populations. Hierarchical clustering of the samples using the 42 genes demonstrated that samples mainly clustered in the same population. CONCLUSION: These results illustrate that microarrays can be used to identify distinct patterns of gene expression in different populations, but with no direct association to clinicopathological parameters. The fact that 67% of the 39 genes with known functions found in this work were previously reported in oral/head and neck tumors from other populations provides clear evidence that development of these tumors follows the same biological pathways irrespective of the source of the samples used.

Prevalence of viral (HPV, EBV, HSV) infections in oral submucous fibrosis and oral cancer from India.

CONCLUSION: There is a high prevalence of human papilloma viruses (HPV) in oral submucous fibrosis (OSMF) and the etiologic implication of this finding warrants further studies. OBJECTIVE: The prevalence of oral squamous cell carcinoma (OSCC) and OSMF is high in India, and the diseases are partly attributed to high consumption of betel quid containing areca nut and tobacco. This study investigated the prevalence of HPV, herpes simplex virus (HSV), and Epstein­Barr virus (EBV) DNA in two groups of patients using betel quid with tobacco, those with OSMF (n = 12) and those with OSCC (n = 62). METHODS: DNA was extracted from all the samples and viral genome was examined by PCR/DNA sequencing. HPV-positive samples were analyzed separately for the high-risk types HPV 16 and 18. RESULTS: HPV DNA, HSV DNA, and EBV DNA were detected in 11 (91%), 1 (8%), and 3 (25%) of the 12 samples from patients with OSMF compared with 15 (24%), 3 (5%), and 18 (29%), respectively, from 62 patients with OSCC. HPV 16 and 18 DNA was detected in 8/12 (67%) in the OSMF group and 10/62 (16%) in the OSCC group. The difference between presence of HPV DNA in OSMF and OSCC groups was statistically significant, while the difference between HSV and EBV DNA content in OSMF and OSCC groups was insignificant.

Pattern of malignant tumors registered at a referral oral and maxillofacial hospital in Sudan during 2006 and 2007.

BACKGROUND: A progressive increase in the incidence and mortality of oral cancer is expected in Sudan. However, updated information on the epidemiology and pattern of the disease in the country is needed to draw the attention of the local authorities. AIM: The aim of this study has been to describe the pattern of cancer cases attending a referral oral and maxillofacial hospital in Sudan during the period 2006-2007. SETTINGS AND DESIGN: The investigation was conducted as a cross-sectional study using the hospital records. MATERIALS AND METHODS: From the hospital database, all cancer cases registered during the study period have been reported and their demographic characteristics, clinical information and history of oral habits were included. STATISTICS: Statistical Package for Social Sciences (version 12) was used for data analysis. Frequency distributions of the study variables were made and the association between pairs of variables was examined using the Chi-square test with a level of significance of 0.01. RESULTS AND CONCLUSION: Of the 261 cases included in this study, the most common pattern was found to be an intraoral squamous cell carcinoma (73.6%). The male to female ratio was approximately 3:2. Dropout rates were alarmingly high regardless of the patient's state of residence. The observation of this study indicated that most of the patients seek treatment when the tumor reaches late stage. More public health efforts are therefore needed to investigate the current impact of the problem as well as for prevention and early detection of the cases.

Sympathectomy suppresses tumor growth and alters gene-expression profiles in rat tongue cancer.

Sympathetic nerves are known to affect carcinogenesis. Recently we found that sympathetic denervation decreases the size of rat tongue tumors. To identify genes involved in rat tongue carcinogenesis and to study the effect of sympathetic nerves on these genes, we compared gene-expression profiles in normal rat tongue (control) and in tumor-induced tongues with (SCGx) and without (Sham) bilateral sympathectomy. Significance analysis of microarrays revealed 280 genes (168 up-regulated, 112 down-regulated) that showed at least a twofold differential expression between Sham and SCGx tumors (false discovery rate < 5%). These included genes associated with cell adhesion, signaling, structure, proliferation, metabolism, angiogenesis, development, and immunity. Hierarchical clustering demonstrated that controls and sympathectomized tumors grouped together, while Sham tumors grouped separately. We identified 34 genes, known to be involved in carcinogenesis, that were not differentially expressed between sympathectomized tumors and control tongues, but which showed a significant change in expression in Sham tumors. Microarray results of 12 of these genes were confirmed by quantitative reverse transcription-polymerase chain reaction. In conclusion, sympathectomy significantly altered the gene-expression profile and inhibited tumor growth. The expression of several cancer genes were increased more than threefold in Sham tumors, but unaltered in the sympathectomized tumors when compared with controls, indicating that these genes may be of significance in rat tongue carcinogenesis.

Chromosomal aberrations in head and neck squamous cell carcinomas in Norwegian and Sudanese populations by array comparative genomic hybridization.

We used microarray-based comparative genomic hybridization to explore genome-wide profiles of chromosomal aberrations in 26 samples of head and neck cancers compared to their pair-wise normal controls. The samples were obtained from Sudanese (n=11) and Norwegian (n=15) patients. The findings were correlated with clinicopathological variables. We identified the amplification of 41 common chromosomal regions (harboring 149 candidate genes) and the deletion of 22 (28 candidate genes). Predominant chromosomal alterations that were observed included high-level amplification at 1q21 (harboring the S100A gene family) and 11q22 (including several MMP family members). Regions of copy number increase was also identified at 6p21 (p21), 7p12 (EGFR), 17p13 (p53) and 19p13.2 (p19INK4d), while regions showing deletion included among others 3p25.2 (RAF1) and 9p21 (p15, p16). We found genes from four common biological pathways (MAPK signaling, cytokine-cytokine receptor interaction, ECM-receptor interaction and Jak-STAT signaling) to be predominantly over-represented in areas of gain and loss. The current study provides valuable information on chromosomal aberrations likely to be involved in the pathogenesis of head and neck cancers. An increased copy number of the S100A and MMP gene family members, known to be involved in invasion and metastasis, may play an important role in the development of the tumors. Hierarchical clustering of the chromosomal alterations with clinicopathological parameters showed little correlation, suggesting an occurrence of gains/losses regardless of ethnic differences and clinicopathological status between the patients from the two countries. Our findings indicate the existence of common gene-specific amplifications/deletions in these tumors, regardless of the source of the samples or attributed carcinogenic risk factors.