Circulating immune complexes as an immunological marker in premalignant and malignant lesions of the oral cavity

Possible Immunotherapeutic Strategies Based on Carcinogen-Dependent Subgroup Classification for Oral Cancer

The oral cavity serves as an open local organ of the human body, exposed to multiple external factors from the outside environment. Coincidentally, initiation and development of oral cancer are attributed to many external factors, such as smoking and drinking, to a great extent. This phenomenon was partly explained by the genetic abnormalities traditionally induced by carcinogens. However, more and more attention has been attracted to the influence of carcinogens on the local immune status. On the other hand, immune heterogeneity of cancer patients is a huge obstacle for enhancing the clinical efficacy of tumor immunotherapy. Thus, in this review, we try to summarize the current opinions about variant genetic changes and multiple immune alterations induced by different oral cancer carcinogens and discuss the prospects of targeted immunotherapeutic strategies based on specific immune abnormalities caused by different carcinogens, as a predictive way to improve clinical outcomes of immunotherapy-treated oral cancer patients.

PTMA, a new identified autoantigen for oral submucous fibrosis, regulates oral submucous fibroblast proliferation and extracellular matrix

Oral submucous fibrosis (OSF) is a chronic, insidious disease. The presence of autoantibodies in sera of OSF patients is the most characteristic and direct evidence of OSF being an autoimmune disease. To identify the specific autoantigens which could contribute to antibody production, the Human Proteome Microarrays composed of 19000 full-length unique proteins were employed. 45 proteins correlated with OSF were identified. To validate these results, we used ELISA to validate 28 OSF-associated autoantigens in extended samples. 8 autoantigens were positive in OSF serum with high frequency compared to the healthy controls. Moreover, the mRNA expression of 8 candidates was up-regulated in OSF oral submucous tissues; among them, the protein level of PTMA, the one with the highest positive frequency, was also increased. Through searching the Bioinformatics Public Database and performing the Spearman’s rank correlation analysis, we observed that PTMA was positively correlated with fibrosis-related TGFβ1 and SMAD4, the downstream gene of TGFβ1. In TGFβ1-induced fibrosis model of primary human oral submucous fibroblast, PTMA knockdown reversed TGFβ1-induced fibrosis process through inhibiting the cell viability and proliferation of fibroblast, reducing the protein levels of PTMA, Collagen I, α-SMA and MMP9 and increasing the protein levels of SMAD4. In contrast, PTMA overexpression enhanced TGFβ1-induced fibrosis process. Taken together, PTMA is involved in TGFβ1-induced fibrosis in the primary human submucous fibroblast by regulating the expression of ECM-related markers and the downstream genes of TGFβ1. In conclusion, PTMA presents an essential autoantigen during OSF process; targeting PTMA might be a promising strategy for OSF treatment.

Estimation of serum and salivary immunoglobulin G and immunoglobulin A in oral pre-cancer: A study in oral submucous fibrosis and oral lichen planus

Aim:

Oral submucous fibrosis (OSMF) and oral lichen planus (OLP) are two frequently reported, potentially malignant disorders with multifactorial etiologies and ambiguous pathogenesis. An immunological pathogenesis has been hypothesized as a causative factor for both. The present study aims to evaluate the role of serum and salivary immunoglobulin G (IgG) and immunoglobulin A (IgA) in both these conditions, by their quantitative estimation.

Materials and Methods:

Saliva and serum samples were collected from 30 patients, clinically diagnosed and histopathologically confirmed with OSMF, 30 with OLP and 30 age and sex matched controls. The levels of IgG and IgA were estimated by nephelometry.

Results:

The mean values of serum IgG were marginally higher in both OSMF and OLP groups compared to the controls but this difference was not significant and the mean values of serum immunoglobulin A were marginally decreased in both the study groups compared to the controls but this difference was also not significant. Inconclusively low levels of salivary IgG and IgA were obtained in the three groups.

Conclusion:

The present study suggests an insignificant association of these immunoglobulins in the pathogenesis of both these diseases.

E, S. S, R. M, R. P, K.R. G. Estimation of Circulating Immune Complexes in patients with Oral Leukoplakia and Oral Submucous Fibrosis: A Case Control Study

PURPOSE OF THE STUDY

The present study was conducted to estimate the serum levels of Circulating Immune Complexes in patients with Oral Leukoplakia ,Oral sub mucous fibrosis and normal subjects and correlate these values with the clinical grades of the diseases.

MATERIALS AND METHODS

The study consisted of 25 Oral Leukoplakia patients, 25 Oral sub mucous fibrosis patients and 25 Normal subjects.

RESULTS

The mean serum levels of CIC showed a gradual increase from normal subjects to Oral Leukoplakia patients and showed a high values in Oral sub mucous fibrosis patients. The mean serum levels of CIC also showed a gradual increase from clinical grade I to grade IV of Oral sub mucous fibrosis.

CONCLUSION

Serum levels of CIC may be taken as a prognostic marker for disease progression of patients with Oral Leukoplakia and Oral sub mucous fibrosis.

Betel quid use in relation to infectious disease outcomes in Cambodia

OBJECTIVES

The habitual chewing of betel quid (areca nut, betel leaf, tobacco) is estimated to occur among 600 million persons in Asia and the Asia-Pacific Region. Emerging data from rural Asia indicate that the betel quid is part of traditional medicine practices that promote its use for a wide range of ailments, including infectious disease. In the present study, we examined the association between betel quid, traditional medicine, and infectious disease outcomes.

METHODS

For the purpose of a nationwide, interviewer-administered, cross-sectional survey of tobacco use (including betel quid), we conducted a stratified three-stage cluster sampling of 13 988 adults aged 18 years and older from all provinces of Cambodia.

RESULTS

We found an association between the intensity of betel quid use and HIV/AIDS (odds ratio (OR) 2.06, 95% CI 1.09-3.89), dengue fever (OR 2.40, 95% CI 1.55-2.72), tuberculosis (OR 1.50, 95% CI 0.96-2.36), and typhoid (OR 1.48, 95% CI 0.95-2.30). These associations were even stronger in women - the primary users of betel quid in Cambodia. Multivariable analyses that controlled for age, gender, income, education, urban versus rural dwelling, receiving care from traditional medicine practitioners, and cigarette smoking did not alter the betel quid-infectious disease association.

CONCLUSIONS

Our findings raise the possibility of a role of betel quid use in the transmission of infectious disease through pathways such as immunosuppression, oral route of entry for a pathogen (i.e., through injury to the oral mucosa), and contamination (i.e., fecal-oral) of the betel quid ingredients.

Circulating Immune complexes (CIC) as marker for disease progress in oral cancer

Oral Cancer is one of the five leading sites of cancer in Indian population. The circulating immune complexes were investigated in 100 serum samples of 60 oral cancer patients having different grades of the disease and 40 patients with precancerous lesions obtained from Nair Hospital Dental collage, Mumbai. The results obtained were compared with those of group of 40 healthy blood donors. Elevated levels of Circulating Immune Complexes were observed in oral cancer patients and patients with oral precancerous lesions. 92% positive samples were observed in well differentiated squamous cell carcinoma whereas 100% positive samples were observed in both moderately and poorly differentiated squamous cell carcinoma. Oral leukoplakia and oral submucous fibrosis showed 15% and 90% positivity respectively. Increased level of Circulating Immune complexes in high grade tumor suggest that Circulating Immune complexes is likely to contribute in evaluating the degree of malignancy, but follow up study is needed to draw any conclusion regarding it's prognostic role.

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.

Modulatory efficacy of green tea polyphenols on glycoconjugates and immunological markers in 4-Nitroquinoline 1-oxide-induced oral carcinogenesis-A therapeutic approach

Green tea polyphenols (GTP) has been used as a chemopreventive agent world wide against chemically induced cancer. The present study is aimed to understand the therapeutic action of GTP on glycoconjugates and immunological markers in 4-Nitroquinoline 1-oxide (4-NQO)-induced oral cancer over a period of 30 days at 200mg/kg, p.o., Oral cancer was induced by painting 4-NQO for 8 weeks followed by administration of GTP after 22 weeks, for 30 days. Glycoconjugates such as hexose, hexosamine, sialicacid, fucose and mucoprotein were analysed. Expression of glycoconjugates was examined through histology and SDS-PAGE. Immunological markers such as circulating immune complex and mast cell density were studied. Oral cancer-induced animals showed a significant increase in levels of glycoconjugates and its expression, similar to that observed for immunological markers. Treatment with GTP altered the expression of glycoconjugates as well as immunological markers. The results suggest that GTP modulates both the expression of glycoconjugates and immunological markers resulting in regression of oral cancer.

Cell-mediated immunity and head and neck cancer: with special emphasis on betel quid chewing habit

Betel quid (BQ) chewing is popular in Taiwan, India, and many southeast-Asian countries. BQ chewing has strong association with the risk of oral leukoplakia (OL), oral submucous fibrosis (OSF), and oral cancer (OC). BQ components exhibit genotoxicity and may alter the structure of DNA, proteins and lipids, resulting in production of antigenicity. BQ ingredients are also shown to induce keratinocyte inflammation by stimulating the production of prostaglandins, TNF-alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in keratinocytes. These events may provoke tissue inflammation, early cell-mediated immunity (CMI), and immune surveillance in BQ chewers. However, BQ components also directly affect the functional activities of immunocompotent cells, and moreover tumor cells may hypo-respond to the CMI via diverse mechanisms such as induction of apoptosis of lymphocytes, induction of production of suppressor T cells, downregulation of MHC molecules in tumor cells, etc. Clinically, an alteration in lymphocyte subsets, a decrease in total number of lymphocytes, and a reduction in functional activities of CMI have been observed in isolated peripheral blood mononuclear cells (PBMC) and tumor infiltrated lymphocytes (TIL) in patients with OSF, OL or OC. Adaptation of tumor cells to immune system may promote clonal selection of resistant tumor cells, leading to immune tolerance. Future studies on effects of BQ components on CMI and humoral immunity in vitro and in vivo can be helpful for chemoprevention of BQ-related oral mucosal diseases. To elucidate how virus infection, tobacco, alcohol and BQ consumption, and other environmental exposure affect the immune status of patients with oral premalignant lesions or OC will help us to understand the immunopathogenesis of OC and to develop immunotherapeutic strategies for OC.

High incidence of autoantibodies in Taiwanese patients with oral submucous fibrosis

BACKGROUND

Previous study has shown a high incidence of autoantibodies including antinuclear (ANA), antismooth muscle (SMA), antigastric parietal cell (GPCA), antithyroid microsomal (TMA), and antireticulin antibodies in a small group of 26 patients with oral submucous fibrosis (OSF). The reasons why some of the OSF patients have high titers of autoantibodies in serum have not been completely explained and no further study on autoantibodies in OSF patients has been done in a large group of patients.

METHODS

In this study, we determined the serum levels of ANA, SMA, GPCA, and TMA in a large group of 109 male Taiwanese patients with OSF by an indirect immunofluorescence technique (for ANA, SMA, and GPCA), and by a semiquantitative microtiter particle agglutination test (for TMA). The presence of serum autoantibodies in OSF patients was further correlated with patients' oral habits and the severity of OSF measured by maximum mouth opening (MMO) and sites of involvement.

RESULTS

We found that the frequencies of presence of serum ANA (23.9%), SMA (23.9%), and GPCA (14.7%) in OSF patients were significantly higher than those (9.2, 7.3, and 5.5%, respectively) in healthy control subjects (P < 0.01, P < 0.005, and P < 0.05, respectively). Although the frequency of presence of TMA (5.5%) in OSF patients was also greater than that (2.8%) in healthy control subjects, the difference was not significant (P > 0.05). The presence of serum GPCA in OSF patients was significantly associated with daily areca quid (AQ) consumption (P < 0.05). The presence of serum ANA in OSF patients associated with daily AQ consumption was of borderline statistical significance (P = 0.066). However, no significant correlations were demonstrated between the presence of serum autoantibodies in OSF patients and other variables of oral habits, MMO, and sites of involvement.

CONCLUSION

In this study, all the 109 OSF patients had AQ chewing habit and 73.4% of the OSF patients swallowed the 'juice' of AQ during the chewing process. The presence of serum GPCA and ANA in OSF patients was associated with daily consumption of AQs. AQ chewing caused mucosal microtrauma, and ulcerations facilitated the diffusion of genotoxic and cytotoxic AQ ingredients into the oral and gastric tissues. Altered autoantigens released from AQ ingredients-damaged cells may induce autoantibody production. Higher frequencies of specific HLA-DR antigens in OSF patients may also help autoantibody production. Therefore, we conclude that the high incidence of autoantibodies in OSF patients may be due to AQ chewing habit, toxic AQ ingredients, and genetic susceptibility of the OSF patients.

Pathogenesis of oral submucous fibrosis. Relationship to risk factors associated with oral cancer

Oral submucous fibrosis (OSF) is a chronic disease of the oral mucosa characterized by inflammation and a progressive fibrosis of the lamina propria and deeper connective tissues. It is a condition predominantly seen among people of Indian origin, and an epidemiologic survey done a decade ago showed no less than 250,000 cases in India, a figure that must have increased sharply. OSF is a condition with a high risk of malignant transformation; to date, no conclusive etiologic agent has been identified, although plenty of data have been generated on various aspects of the disease. These include genetic, carcinogenic, immunologic, viral, nutritional, and autoimmune possibilities, all of which also have been implicated in the development of oral cancer. This article reviews existing evidence on the pathogenesis of OSF and its relation to oral cancer and suggests a possible multifactorial model to explain the disease process.

Recent results of oral cancer research in Kerala, India

Findings from a research program in oral cancer at Regional Cancer Centre, Trivandrum, Kerala, India are reviewed. There is evidence of immune impairment in oral cancer patients. Plant lectins are being investigated for specific binding characteristics in various oral precancers and different histological subtypes of oral cancer. Tobacco and alcohol have been identified as the major risk factors for oral cancer. The chemopreventive potential of carotenoids and retinoids have been evaluated in oral leucoplakias. Beta-carotene and vitamin A in heavier doses induced remission of oral leukoplakias in 25%-50% of trial participants who continued with their tobacco and alcohol habits during the trial. The remission could be maintained with lower doses. Less than 20% of our patients with oral cancer were initially seen in localized stages. Various community-oriented programs for prevention of primary and secondary oral cancers are being evaluated. These include antitobacco health education, oral self-examination, and oral examination by trained volunteers. The results of radical radiotherapy and surgical salvage of radiation failure are also discussed. The 5-year disease-free survival rate of 34% is a reflection of the advanced stages of the disease when initially seen. Salvage rates with surgery for radiation failures were encouraging.