Association of CTLA-4 gene polymorphism with oral submucous fibrosis in Taiwan

Immunopathogenesis of oral submucous fibrosis by chewing the areca nut

Oral submucous fibrosis (OSF) is a chronic, progressive, scarring, and premalignant disease of the oral mucosa. Its pathogenic factors are complex and include chewing areca nuts or other spicy food items, nutrition, and genetic and immune factors. Recently, immune factors have become the focus of medical research, with increased attention being paid to the role of immune regulation in diseases, particularly tumors. OSF is accompanied by obvious changes in the immune microenvironment. The aim of this review is to discuss the potential relationship of OSF and areca nuts genetic with the immune system, including lymphocytes, macrophage, Langerhans cell, mast cell, and substances released by activated immune cells, to determine the pathogenesis and treatment of OSF from an immunologic viewpoint.

Oral submucous fibrosis: A global challenge. Rising incidence, risk factors, management, and research priorities

Oral submucous fibrosis is a potentially malignant disorder of the oral cavity, with a high rate of malignant transformation. It is very common among habitual areca nut chewers. The pathogenesis of oral submucous fibrosis is not well established, but it is believed to be a disease of multifactorial origin, including areca nut chewing, ingestion of chilies, genetic factors, immunologic processes and nutritional deficiencies. Genetically susceptible individuals when exposed to areca nut chewing develop this disease over a variable period of time. Oral submucous fibrosis is considered to be a disease of collagen metabolism. Several genetic factors are reported but there is no consensus about the exact mechanism of disease initiation. Variations in histopathological presentation are noted among oral submucous fibrosis patients with habitual areca nut chewing in different forms and other additive agents, eg betel quid, pan masala and gutkha, together with a variety of tobacco habits. The role of epigenetic modifications, such as miRNA regulation, and DNA methylation is also being reported as part of the pathogenesis of oral submucous fibrosis. A combined approach, including analysis of genetic and epigenetic regulations with different habits, might be helpful to better understand the contributory factors and pathogenesis of this serious disorder.

Comparative Evaluation of role of Lysyl oxidase gene (LOXG473A) expression in pathogenesis and malignant transformation of Oral Submucous Fibrosis

Background

Identification and comparison of gene expression of Lysyl oxidase (LOX) in oral submucous fibrosis and controls and to determine its role in Pathogenesis of Oral submucous fibrosis.

Material and Methods

Of total sample size (n=127), the whole blood sample were collected from case and control group in citrate vial. It is centrifused and stored at -800C. We collected and isolated RNA from blood of case group (n=127) and age and sex matched control group (n=127) recruited on the basis of inclusion criteria. The cDNA was prepared for 127 samples which were processed for gene expression of Lysyl oxidase (LOX) in relation to housekeeping genes (Beta actin and 18srRNA) and its role in pathogenesis of Oral submucous fibrosis.

Results

In relative expression (Normalized ratio),relatively 11 cases shown down-regulation of lysyl oxidase gene while 27 cases shows up-regulation of lysyl oxidase gene while in 89 cases there were no regulation i.e expression of lysyl oxidase gene in case group was of same degree of control. In non-relative expression results (Non-normalized ratio), the 38 cases shown down regulation of LOX gene while in 53 cases, it was up-regulated however in remaining 36 cases there was neither up-regulation nor down-regulation of Lysyl oxidase gene i.e the expression of LOX gene is null.

Conclusions

In oral submucous fibrosis, the expression of Lysyl oxidase gene is mixed type i.e either it will down regulate/upregulate or there will be no expression at all comparatively. However in majority of cases the upregulation of lysyl oxidase is relatively more common than down-regulation or non expression of Lysyl oxidase gene.

Key words:Oral submucous fibrosis, lysyl oxidase, betel nut, premalignant disorders.

Estimation of Salivary and Serum Lactate Dehydrogenase in Oral Submucous Fibrosis

AIM AND OBJECTIVES

The objective of the present study was to estimate the serum and salivary lactate dehydrogenase (LDH) levels in patients with oral submucous fibrosis (OSMF) and to study the association between serum and salivary LDH levels and mouth opening, frequency of habit, and duration of habit in patients with OSMF.

MATERIALS AND METHODS

Participants were divided into two groups: Group I - case group diagnosed with OSMF and Group II - the control group. Unstimulated whole saliva was collected from all the participants. The International Federation of Clinical Chemistry method was carried out with the help of LDH (P-L) kit (Crest Biosystems, Goa). Collection of blood sample was done under aseptic precautions and processed for LDH. The data were analyzed using SPSS software 2010 (version 19, IBM, Armonk, NY, USA). Descriptive statistics including mean, range, standard deviation, and percentage were used along with unpaired t-test and Pearson's correlation test.

RESULTS

All the participants were male and were in the age range of 18-60 years, with a mean age of 28.63 ± 10.39 years. The mean salivary LDH levels in patients with OSMF were 1057.30 ± 640.12 μg/dl and in the control group were 668.25 ± 498.45 μg/dl. The mean serum LDH level in patients with OSMF was 408.35 ± 158.35 μg/dl as compared to the control group was 313.05 ± 82.69 μg/dl. The Pearson's correlation coefficient between serum LDH and frequency of habit, duration of habit, and mouth opening was found to be 0.55, 0.53, and 0.69, respectively. The Pearson's correlation coefficient between salivary LDH and frequency of habit, duration of habit, and mouth opening was found to be 0.33, 0.04, and 0.13, respectively. The Pearson's correlation coefficient between salivary LDH and serum LDH was found to be -0.18.

CONCLUSIONS

There was a significant increase in the serum and salivary LDH in OSMF patients as compared to controls; the salivary LDH did not seem to correlate with frequency of the habit, duration of the habit, or mouth opening of OSMF patients. However, serum LDH was found to correlate directly with frequency of the habit and mouth opening in OSMF patients. Hence, based on the results of the present study, it can be hypothesized that serum LDH is a better biological marker than salivary LDH in the evaluation of OSMF.

Areca nut in pathogenesis of oral submucous fibrosis: revisited

BACKGROUND

Oral submucous fibrosis is a disease due to a chronic, insidious change in fibro-elasticity, characterized by burning sensation in the oral cavity, blanching, and stiffening of the oral mucosa and oropharynx leading to trismus and inability to open the mouth. The symptoms and signs depend on the progression of the lesions and number of affected sites. It is predominantly seen in Indians and other Asians. Once the disease has developed, there is neither regression nor any effective treatment. It is considered as a pre-malignant stage of oral cancer, and the reported risk of malignant transformation varies from 2.3-7.6%.

CONCLUSIONS

The common etiological factor considered for this unremitting disease is use of areca nut; however, the precise mechanism still remains elusive and controversial. A wide range of treatment consisting of drugs, surgical therapy, and physiotherapy have been attempted till date, with varying degrees of benefit, but none of them have proved to be a cure for this disease. This field remains open for clinical trials and research. This paper aims to give an overview on the role of areca nut in the pathogenesis and malignant potential of oral submucous fibrosis.

Association of T-cell regulatory gene polymorphisms with oral squamous cell carcinoma

Costimulatory molecules have complementary effects on T-cell activation and their balance may control the development of oral cancer. The aim of this study was to determine the relevance of cytotoxic T-lymphocyte antigen 4 (CTLA-4), CD28 and inducible costimulator (ICOS) polymorphisms in oral squamous cell carcinoma (OSCC). Genotyping for CTLA-4 (-1661 A/G and +49 A/G), CD28 (0 C/G and +3160 G/T) and ICOS (+637 A/C and +1599 C/T) was performed in the 83 patients with OSCC, compared to the 40 unrelated healthy volunteers as controls. The genotype CTLA-4 -1661 was significantly different between the patient group and the control group. The allele CTLA-4 -1661 G was significantly found more frequent in patients with OSCC (p=0.001). In bivariate analysis, noticeable differences between OSCC and controls were seen. The combinations CTLA-4 -1661 G/G and CTLA-4 +49 A/G, ICOS +1559 C/T and ICOS +1559 C/C each with CTLA-4 -1661 G/G, ICOS +637 C/C and ICOS +637 A/C each with CTLA-4 -1661, CTLA-4 -1661 A/G and ICOS +637 C/C, CD28 +3160 G/T and CTLA-4 -1661 A/A and CD28 +3160 G/T and CTLA-4 -1661 A/G were seen in the patient group only. Especially the polymorphisms of the CTLA-4 -1661-genotype - alone and in combination with other T cell regulator polymorphisms - seem to be possible predisposing factors for OSCC. Therefore, they might be future targets for a primary prophylaxis or an individualised therapy.

Management of oral submucous fibrosis: an overview

Oral submucous fibrosis is a disease due to a chronic, insidious change in fibroelasticity, characterized by burning sensation in the oral cavity, blanching, and stiffening of the oral mucosa and oro-pharynx leading to trismus and inability to open the mouth. The symptoms and signs depend on the progression of the lesions and number of affected sites. It is predominantly seen in Indians and other Asians. Once, the disease has developed, there is neither regression nor any effective treatment. It is considered as a pre-malignant stage of oral cancer and reported risk of malignant transformation varies from 2.3-7.6%.The common etiological factor considered for this unremitting disease is use of areca nut; however, the precise pathogenesis still remains elusive and controversial. A wide range of treatment consisting of drug management, surgical therapy, and physiotherapy have been attempted till date; with varying degrees of benefit, but none of them have proved to be a cure for this disease. This field remains open for clinical trials and research. This paper aims to provide an overview on various management modalities available for oral submucous fibrosis.

Synergistic effect of stromelysin-1 (matrix metalloproteinase-3) promoter (-1171 5A->6A) polymorphism in oral submucous fibrosis and head and neck lesions

BACKGROUND

Matrix metalloproteinases (MMPs) are enzymes that degrade all the components of extra cellular matrix and collagen. Various types of MMPs are known to be expressed and activated in patients with oral submucous fibrosis (OSMF) as well as head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to asses the association of the single nucleotide polymorphism (SNP) adenosine insertion/deletion polymorphism (-1171 5A->6A) in the MMP-3 promoter region in these lesions.

METHODS

MMP-3 SNP was genotyped by polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) analysis in a case control study consisting of 362 participants; 101 cases of OSMF, 135 of HNSCC and 126 controls, compared for age, sex and habits. ROC distribution was plotted to assess the contributions of genetic variation in MMP-3 genotypes with relation to age.

RESULTS

Analysis of MMP 3 (-1171 5A->6A) polymorphism revealed the frequency of 5A allele in OSMF, HNSCC and controls to be 0.15, 0.13 and 0.07, respectively. A significant difference was found in 5A genotype frequency between OSMF (5A genotype frequency = 0.15, p = 0.01, OR = 2.26, 95% CI = 1.22-4.20) and in controls (5A genotype frequency 0.07) as well as HNSCC (5A genotype frequency 0.13, p = 0.03,95%CI = 1.06-3.51) and controls (5A genotype frequency = 0.07) In this study, 5A genotype had greater than two fold risk for developing OSMF (OR = 2.26) and nearly the same in case of HNSCC (OR = 1.94) as compared to controls. In patients with OSMF as well as HNSCC, the ROC analysis between the MMP-3 genotype and age, 6A/6A allele was found to be significant in patients both over and under 45 years of age; while the 5A/5A carrier alleles showed an association only in patients less than 45 years of age.

CONCLUSIONS

This study concluded that the expression of MMP-3 genotype associated with the 5A alleles, it may have an important role in the susceptibility of the patients to develop OSMF and HNSCC.

Association between lysyl oxidase polymorphisms and oral submucous fibrosis in older male areca chewers

OBJECTIVE

Areca use is the major cause for oral squamous cell carcinoma and oral submucous fibrosis (OSF) in South Asians. Lysyl oxidase (LOX) is a copper-activated enzyme critical for collagen cross-linking and organization of extracellular matrix. The presence of a G to A polymorphism at nucleotide 473 caused a non-conservative Arg158Gln change in the LOX amino acid sequence. OSF is a precancerous lesions characterized by the accumulation of collagen in oral submucosa. The aim of this study was to investigate the relationship between LOX Arg158Gln polymorphism and the risk of OSF.

METHOD

PCR-restriction fragment length polymorphisms and direct sequencing was utilized to compare LOX polymorphic allelotype in male areca-chewing controls (n = 216) and OSF (n = 83) patients.

RESULTS

There was a borderline of statistically significant difference in Arg158Gln genotype lying between control and OSF patients. However, the G/A+A/A of LOX Arg158Gln in OSF patients older than 50 year was statistically significantly higher than controls older than 50 year (odd's ratio: 4.48; 95% CI = 1.58-12.67).

CONCLUSION

The elder OSF patients were increased in LOX Arg158Gln. Our findings may suggest a potential application in risk population selection using LOX polymorphism for preventive intervention of OSF genesis in a subset of areca chewers.

Oral submucous fibrosis: Review on aetiology and pathogenesis

Data from recent epidemiological studies provide overwhelming evidence that areca nut is the main aetiological factor for OSF. A clear dose-dependent relationship was observed for both frequency and duration of chewing areca nut (without tobacco) in the development of OSF. Commercially freeze dried products such as pan masala, Guthka and mawa (areca and lime) have high concentrates of areca nut per chew and appear to cause OSF more rapidly than by self prepared conventional betel quid that contain smaller amounts of areca nut. It is logical to hypothesise that the increased collagen synthesis or reduced collagen degradation as possible mechanisms in the development of the disease. There are numerous biological pathways involved in the above processes and, it is likely that the normal regulatory mechanisms are either down regulated or up regulated at different stages of the disease. Among the chemical constituents, alkaloids from areca nut are the most important biologically whilst tannin may have a synergistic role. These chemicals appear to interfere with the molecular processes of deposition and/or degradation of extracellular matrix molecules such as collagen. In vitro studies on human fibroblasts using areca extracts or chemically purified arecoline support the theory of fibroblastic proliferation and increased collagen formation that is also demonstrable histologically in human OSF tissues. The copper content of areca nut is high and the possible role of copper as a mediator of fibrosis is supported by the demonstration of up regulation of lysyl oxidase in OSF biopsies. It has been postulated that areca nut may also induce the development of the disease by increased levels of cytokines in the lamina propria. Increased and continuous deposition of extracellular matrix may take place as a result of disruption of the equilibrium between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMP). Current evidence implicates collagen-related genes in the susceptibility and pathogenesis of OSF. The individual mechanisms operating at various stages of the disease-initial, intermediate and advanced-need further study in order to propose appropriate therapeutic interventions.

The functional (-1171 5A-->6A) polymorphisms of matrix metalloproteinase 3 gene as a risk factor for oral submucous fibrosis among male areca users

BACKGROUND

Insertion/deletion (-1171 5A-->6A) polymorphisms in the promoter region of matrix metalloproteinase 3 (MMP3) gene result in different transcriptional activities. MMP3 is able to degrade collagens types II, V, IX, and X, and other extracellular matrix. The functional promoter polymorphism of MMP3 has been related to the susceptibility in some inflammatory diseases and metastasis of cancers.

METHODS

Oral submucous fibrosis (OSF) and oral squamous cell carcinoma (OSCC) are prevalent among Asian areca users. In this study, genomic DNA obtained from the blood of OSCC (n = 150), OSF (n = 71), and control non-diseased areca user (n = 98) in male were subjected to polymerase chain reaction (PCR)-based genotyping of MMP3.

RESULTS

The 5A genotype in MMP3 promoter was observed more frequently in OSF group than in control group (P = 0.01). No significant difference was noted between OSCC and control groups on the 5A genotype frequency (P = 0.18). No association was found between 5A genotype in MMP3 promoter and site or lymph node metastasis and stage of OSCC.

CONCLUSION

The results indicated that the 5A genotype of MMP3 promoter was associated with the risk of OSF but not OSCC.

Functional polymorphism in NFKB1 promoter is related to the risks of oral squamous cell carcinoma occurring on older male areca (betel) chewers

Areca (betel)-chewing is tightly associated with the high prevalence of oral squamous cell carcinoma (OSCC) in Asians. NFKB1 encodes a 105kDa protein that can be processed to produce p50 subunit of nuclear factor-kappaB protein complex. A insertion (ins)/deletion (del) polymorphism (-94ins/delATTG) in NFKB1 promoter, which may drive the ins allele two-fold increase in NFKB1 transcription relative to del allele, was recently found. This study identified that the odds ratio in OSCC carrying ins allelotype were 1.78 relative to controls (56.7 vs 41.8%) in subjects more than 50 years old. L allelotype of Heme oxygenase-1 (HO-1), accounting for a long (GT)(n) repeat in HO-1 promoter, is associated with the risks of areca-related OSCC. Subjects carried both NFKB1 ins and HO-1 L allelotypes had significant risks for various subsets of OSCC. OSCC with lymph node metastasis or advanced stage had significantly higher frequency of NFKB1 ins and HO-1 L allelotypes. This study suggested that the functional NFKB1promoter polymorphism could be valuable for assessment of cancer risk.

Association of CTLA-4 gene polymorphism with oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a worldwide problem. The main mechanism of tumor immunity is the destruction of tumor cells by cytolytic T lymphocytes. Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4; CD152), a negative regulator of T-lymphocyte activation, plays an extremely important role in the immune tolerance and anergy. This study was designed to investigate the role of CTLA-4 polymorphism in OSCC.

METHODS

The CTLA-4 +49 A/G polymorphism was studied in 118 patients with OSCC and 147 healthy controls by using restriction fragment length polymorphism (RFLP). The genotype and phenotype frequencies were evaluated in Fisher's exact test.

RESULTS

There was no significant difference in the frequency of CTLA-4 polymorphism between the OSCC study group and healthy controls. The CTLA-4 A/A genotype was significantly associated with a younger age of onset of OSCC (P = 0.04). The AA genotype was associated with significantly poorer survival (P = 0.003).

CONCLUSION

The present study is the first to shows that the A/A polymorphism is associated with poor survival in OSCC in Taiwan.

Angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with risk of oral precancerous lesion in betel quid chewers

To investigate whether angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is related to the risk of oral precancerous lesions (OPL) in Taiwanese subjects who chew betel quid, a total of 61 betel quid chewers having OPL were compared with 61 asymptomatic betel quid chewers matched for betel quid chewing duration and dosage. The frequency of homozygote for ACE D variant is significantly higher in the case subjects than that of the controls (44.3 vs 24.6%; P=0.0108). The adjusted odds ratio of the D homozygous for the risk of OPL is 8.10 (95% confidence interval (CI)=2.04–32.19, P=0.003). In the allelic base analysis, the D allele is also significantly associated with higher risk of OPL. When grouping the study subjects by smoking status, the association between ACE I/D polymorphism and risk of OPL was only observed in nonsmokers. Our results support the theory that genetic factors may contribute to the susceptibility of OPL and suggest that smoking and genetic factors may be differently involved in the development of OPL.

Polymorphism in heme oxygenase-1 (HO-1) promoter is related to the risk of oral squamous cell carcinoma occurring on male areca chewers

Areca (betel) chewing is associated with the high incidence of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF) in Asians. Heme oxygenase-1 (HO-1), encoding an oxidative response protein, plays protective roles in cells. A (GT)_n microsatellite repeat in HO-1 promoter shows polymorphisms and modulates the level of gene transcription. We examined allelotypic frequencies of (GT)_n repeats in 83 controls, 147 OSCC and 71 OSF. All subjects were male areca chewers. Logistic regression was used to adjust the age confounding for odds ratio (OR). (GT)_n repeat polymorphism was classified into short (S), medium (M) and long (L) alleles. The adjusted OR in OSCC subjects carrying L allelotype relative to S allelotype was 1.75. Buccal squamous cell carcinoma (BSCC) is the most common OSCC subset in areca chewers. L allelotype implied the risk of BSCC with adjusted OR of 2.05, whereas M allelotype appeared protective for non-BSCC with adjusted OR of 0.49. Our findings indicated that longer (GT)_n repeat allele in HO-1 promoter is associated with the risks of areca-related OSCC, while the shorter (GT)_n repeat allele may have protective effects for OSCC.