Leukoplakia Lesions Research Articles

A new classification of vocal fold leukoplakia by morphological appearance guiding the treatment

Objective: To provide a reference for classification and treatment of vocal cords leukoplakia.Methods: 640 cases of patients with vocal cords leukoplakia were divided into three groups based on the appearances. There were respectively 81 smooth flat lesions, 155 smooth hypertrophy lesions and 13 rough lesions were treated with conservative methods and 26, 153 and 212 cases were resected surgically for biopsy.Results: A majority of smooth flat leukoplakia lesions were cured by non-operational methods and no atypical hyperplasia. Most of rough lesions were invalid and even progressed treated with conservative therapy and were severe dysplasia or canceration. Although 67.6% smooth hypertrophy lesions were cured or improved by conservative methods and 47% lesions had no or mild dysplasia, over 30% of lesions were still invalid or progressed and over 50% had moderate, severe dysplasia and canceration. By statistical analysis, the appearance of leukoplakia was concordant with pathological changes.Conclusions: It is suggested that smooth flat vocal cords leukoplakia could be treated with conservative methods and rough lesions should be resected operationally, while for smooth hypertrophy vocal cords leukoplakia could be first followed-up and then adopt measures based on the appearance changes.

Immunohistochemical Expression of Podoplanin in Clinical Variants of Oral Leukoplakia and Its Correlation With Epithelial Dysplasia.

Oral leukoplakia is the most common premalignant lesion of the oral cavity and is associated with development of oral squamous cell carcinoma. Certain changes at cellular and molecular level are important indicators for transformation into carcinoma. Podoplanin, a transmembrane glycoprotein is involved in the cytoskeletal remodeling and increased motility of the cell which helps in determining the malignant potential of oral leukoplakic lesions. The objective of the study was to determine immunohistochemically the expression of podoplanin in homogenous (HOL) and nonhomogenous oral leukoplakia (NHOL) and to compare the expression with clinicopathological parameters. Study group included 15 cases each of HOL, NHOL and control group included 15 healthy volunteers. Both tissues were immunohistochemically stained for podoplanin (D2-40) antibody. No statistical significant difference was observed between the study and control groups for expression of podoplanin but significant difference was observed on comparison of podoplanin scores between HOL and NHOL. Statistical significant difference was observed when the podoplanin expression in the epithelium and the lymphatic vessel density were correlated with the histologic grading of HOL and NHOL. Expression of podoplanin was greater in NHOL as compared with HOL, this supports the fact that NHOL has a greater risk of malignant transformation when compared with HOL. Podoplanin expression, lymphangiogenesis, and lymphatic vessel density increased with increasing grades of dysplasia, suggesting that cellular modeling and motility is increased as the grade of dysplasia advances. Thus suggesting podoplanin can be used as a prognostic marker to determine the malignant potential in oral leukoplakias.

Correlation of serum lactate dehydrogenase and alkaline phosphatase in different histological grades of head and neck squamous cell carcinoma and premalignant lesions.

Head neck cancer (HNCA) in North-East India accounts for 54.48% cancers at all sites, one of the highest in the country. Increased serum lactate dehydrogenase (LDH) activity is considered as a marker of cellular necrosis while serum alkaline phosphatase (ALP) is recognized as an important marker of induction of tumor cell differentiation. Considering the importance and need of biomarker in HNCA and there being no previous study on tumor markers from this highly prevalent region, we intended to examine the role of serum LDH and ALP in head and neck squamous cell carcinoma (HNSCC) and epithelial precursor lesions (EPLs) and also to find their correlation with the different histological grades of tumor. This is a prospective observational study on patients with HNSCC and precancerous lesions attending Department of ENT of a Teaching Hospital. Serum LDH and ALP was measured in HNSCC, EPL and control groups and the results were statistically analyzed and compared using analysis of variance, Pearson correlation coefficient, and sensitivity-specificity analysis. Serum LDH was found to be a significant marker of HNSCC. Total serum LDH level was high in both premalignant and HNSCC cases. There was a significant correlation between serum LDH and grades of HNSCC showing highest levels of expression in moderately differentiated SCC. Elevated serum LDH was also seen in erythroleukoplakia, leukoplakia, and verrucous lesion, but serum ALP levels were not significant. This is the first study from this highly prevalent region of HNCA showing that serum LDH could be regarded as a biomarker for malignant and premalignant conditions of the head and neck.

Association between clinical stage of oral cancer and expression of immunohistochemical markers.

The aim of this study is to demonstrate the possible correlation between the expression of examined protein markers - p53, EGFR, PCNA, p44/42 in the mass of the tumor and the clinical stage of disease. 48 patients of the Department and Clinic of Oral and Maxillofacial Surgery, Lublin diagnosed with oral cancer. The control group consisted of 10 patients diagnosed with leukoplakia lesions in the oral cavity. The methods: Immunohistochemical analysis using the detection system DAKO K5007 Cat - Dako REAL ™ Detection System, Peroxidase DAB +, Rabbit / Mouse. Based upon the statistical results, significant correlation between p53 protein and tumor staging; however, a correlation between the level of expression of EGFR, p44/42, PCNA and staging was not likewise revealed. Looking for oral squamous cell carcinoma markers remains an actual issue. Identification of specific markers of oral cancer could be used in screening the population, determining prognosis and response to treatment.

White oral mucosal lesions among the Yemeni population and their relation to local oral habits.

The aim of the present study was to assess the prevalence and risk factors of white oral mucosal lesions among Yemeni adults; in particular, those who chew khat and tobacco. The present cross-sectional study included 1052 dental patients aged 15years and older. A detailed oral examination was performed by a single examiner in accordance with standard international criteria. Overall, 25.2% of the study participants presented with one or more white lesions. The most prevalent lesions were khat-induced white lesion (8.8%), leukoedema (5.1%), and frictional keratosis (3.9%). Potentially malignant lesions, such as lichen planus, leukoplakia, and smokeless tobacco-induced lesions, were seen in 2.4%, 1.2%, and 1.7% of participants, respectively. Moreover, three cases of oral cancer were identified. The presence of white lesions was found to be significantly associated with advanced age (P=.004), male gender (P=.009), and khat/tobacco chewing habits (P<.001). The present study demonstrates a high prevalence of oral benign and potentially malignant white lesions. Further, it highlights the urgent need to develop and implement new government policies to regulate the sale of these products to reduce the prevalence of these lesions and the overall incidence of oral cancers in the Yemeni population.

Considerations in the diagnosis of oral hairy leukoplakia—an institutional experience

We report here the 10-year experience with oral hairy leukoplakia (OHL) at the Division of Oral and Maxillofacial Pathology at the University of North Carolina at Chapel Hill, NC, USA. All the associated hematoxylin and eosin and Epstein-Barr virus encoding region in situ hybridization slides of OHL cases between January 1, 2008, and February 1, 2017, were retrieved and reviewed. Collected demographic characteristics, clinical presentation, medical and social histories were reviewed and reported. Six OHL cases with confirmed in situ hybridization showed predilection for the lateral tongue. The study included 3 females and 3 males (mean age 50.5 years; age range 29-70 years). One patient had known HIV-positive status before biopsy was performed. Three patients had reported a history of heavy smoking. Other medical conditions reported were history of breast cancer, a long history of corticosteroid inhaler use for asthma treatment, high cholesterol, diabetes, and hypertension. The findings of this study indicate the need to include OHL as a potential entity in the differential diagnosis of leukoplakic tongue lesions, regardless of the patient's HIV status. In addition, the presence of OHL in the patient requires investigation of various explanations for EBV infection, including immunosuppression caused by HIV infection or chronic steroid use.

Abstract 2015: Mesenchymal stem cell correlates oral leukoplakia malignant transformation through regulate T cell response

Abstract Introduction Leukoplakia is one of the most common clinically presented oral potential malignant disorders (OPMD). Detailed understanding of leukoplakia-associated molecular or cellular changes would help us better undertand about the progress of leukoplakia malignant transformation. In this study, we examined the potential involvement of MSC in this very progress, and demonstrated lesion resident MSCs may favour leukoplakia malignant transformation through its strong immunoregulation on T cell. Methods Eighteen six-week-old female Sprague-Dawley rats (180-220g) were given 0.05g/L 4NQO in drinking water for 22 weeks for development of lesions. Lesions classfied by histological HE stainnig. MSCs were obtained from single cell suspesion of lesions, and cultured with splenocyte to study its immunoregulate ability. Results 1. MSC-like cells are enriched in carcinogen induced leukoplakia and cancers. Representative results showing the lesions on tongue of rats. And relative proportion of MSC phenotype marker (CD29+, CD31-, CD45-, CD90+) in oral lesions (OMSC) were counted by flow cytometry. 2. Leukoplakia-derived MSC (L-OMSC), cancer-derived MSC (C-OMSC), and the normal mucosa-derived MSC (N-OMSC) share the similar stemness properties. 3. Cancer lesion have less infiltrating T cells (quantified by IHC and FCM of CD3 ). Cancer-derived MSCs suppress T cell proliferation, but not promote T cell apoptosis and inhibit T cell migration to the lesions. 4. Higher number of lesion derived MSCs associates with higher celluar proliferation in the lesions. Summary Our study demonstrated MSCs could migrate to pre-malignant leukoplakia lesions prior to tumor establishment. Further, MSCs play an important role in leukoplakia malignant transformation induced by chemicals, which via its strong immunomodulatory activities. Citation Format: Yichen Chen, Bailin He, Da Ma, Jingjing Song, Xi Wang, Bin Cheng, Zhi Wang. Mesenchymal stem cell correlates oral leukoplakia malignant transformation through regulate T cell response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2015. doi:10.1158/1538-7445.AM2017-2015

Aberrant expression of CK8 in leukoplakia and oral squamous cell carcinoma: an immunohistochemistry study

Introduction: In India, oral cavity cancer contributes to significant morbidity and mortality. Since only few of premalignant lesions turn into cancer and routine histopathology has limited prognostic value, therefore we need to devise methods to ascertain premalignant lesions with high potential for conversion to malignancy, appropriate management and early diagnosis of cancers. Cytokeratin K8 (CK8) may be used as surrogate markers in oral premalignant lesion and cancers, so we conducted the present study with an aim to evaluate & compare expression of CK8 in normal oral mucosa, leukoplakia as well as Oral squamous cell carcinoma (OSCC). Material and Methods: The present study included 107 pathological specimens of histologically proven cases of OSCC (n=19), leukoplakia (n=77) and benign lesions (n=10). All the cases were subjected to immunohistochemistry to check the expression of CK8 antibodies. Correlation was evaluated statistically by Chi-square test. Result: Increased expression of CK8 was seen in OSCC and leukoplakia with dysplasia. No immunoreactivity was seen in benign oral mucosa. Expression of CK8 was significantly correlated with dysplasia and cancer. Conclusion: CK8 can be used as marker of sequential premalignant changes in oral cancers.

Role of Chemiluminescence examination as non-invasive diagnostic tool in early detection of Leukoplakia

ObjectivesTo assess the efficacy of Chemiluminescent light (Vizilite plus) in enhancing visualization and its ability to highlight Leukoplakia lesion. Material and methodsThis was a cross-sectional study done on 40 study subjects. Subjects were inducted into the study irrespective of age and sex based on the specific inclusion and exclusion criteria. The lesion parameters like the location of the lesion, the shape of lesion, the size, the extent, borders and the presence or absence of any adjacent satellite lesions were assessed under Incandescent light followed by Toluidine blue and Vizilite plus examinations. Histopathological examination results were considered as the gold standard and TBLU and CHEM outcomes were compared to them. ResultsVizilite plus examination method was most effective in assessing the size, borders and shape of the lesions followed by Toluidine blue and Incandescent light examinations. Toluidine blue and Vizilite plus examination methods demonstrated the sensitivity of 100% and specificity of 97.3%. They also demonstrated PPV of 100% and NPV of 75% with reliable accuracy of 97.5%. ConclusionChemiluminescent light is a stepping stone and has the potential to revolutionize the diagnostic protocol for patients with potentially premalignant lesions. The device can be used as a general oral mucosal examination system and may in particular improve the visualization of potentially premalignant lesions.

Differentiation-Dependent LMP1 Expression Is Required for Efficient Lytic Epstein-Barr Virus Reactivation in Epithelial Cells.

Epstein-Barr virus (EBV)-associated diseases of epithelial cells, including tumors that have latent infection, such as nasopharyngeal carcinoma (NPC), and oral hairy leukoplakia (OHL) lesions that have lytic infection, frequently express the viral latent membrane protein 1 (LMP1). In lytically infected cells, LMP1 expression is activated by the BRLF1 (R) immediate early (IE) protein. However, the mechanisms by which LMP1 expression is normally regulated in epithelial cells remain poorly understood, and its potential roles in regulating lytic reactivation in epithelial cells are as yet unexplored. We previously showed that the differentiation-dependent cellular transcription factors KLF4 and BLIMP1 induce lytic EBV reactivation in epithelial cells by synergistically activating the two EBV immediate early promoters (Zp and Rp). Here we show that epithelial cell differentiation also induces LMP1 expression. We demonstrate that KLF4 and BLIMP1 cooperatively induce the expression of LMP1, even in the absence of the EBV IE proteins BZLF1 (Z) and R, via activation of the two LMP1 promoters. Furthermore, we found that differentiation of NOKs-Akata cells by either methylcellulose suspension or organotypic culture induces LMP1 expression prior to Z and R expression. We show that LMP1 enhances the lytic infection-inducing effects of epithelial cell differentiation, as well as 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate treatment, in EBV-infected epithelial cells by increasing expression of the Z and R proteins. Our results suggest that differentiation of epithelial cells activates a feed-forward loop in which KLF4 and BLIMP1 first activate LMP1 expression and then cooperate with LMP1 to activate Z and R expression.IMPORTANCE The EBV protein LMP1 is expressed in EBV-associated epithelial cell diseases, regardless of whether these diseases are due to lytic infection (such as oral hairy leukoplakia) or latent infection (such as nasopharyngeal carcinoma). However, surprisingly little is known about how LMP1 expression is regulated in epithelial cells, and there are conflicting reports about whether it plays any role in regulating viral lytic reactivation. In this study, we show that epithelial cell differentiation induces LMP1 expression by increasing expression of two cellular transcription factors (KLF4 and BLIMP1) which cooperatively activate the two LMP1 promoters. We also demonstrate that LMP1 promotes efficient lytic reactivation in EBV-infected epithelial cells by enhancing expression of the Z and R proteins. Thus, in EBV-infected epithelial cells, LMP1 expression is promoted by differentiation and positively regulates lytic viral reactivation.

Predictive value of p63, ki-67, and survivin expression in oral leukoplakia: A tissue microarray study.

The aim of this study was to analyze the immunohistochemical expression of survivin, ki-67, and p63 in oral leukoplakic lesions, histopathologically differentiated into dysplastic and nondysplastic. A tissue microarray containing 57 samples of biopsies from clinically classified lesions, such as leukoplakia, was immunolabeled for survivin, ki-67, and p63. Samples were scored for percentage of positively stained. Scores were designated as follows: low = less than 25% of positive cells; and high = more than 25% of positive cells. On performing histopathological diagnosis, 20 dysplastic lesions and 37 nondysplastic lesions were seen, in which female patients (56.1%) were predominant with an average age of 58.27 years. The study showed a high expression of 37.5% for survivin, 43.7% for ki-67, and 88.2% for p63 in dysplastic lesions. However, there was a high expression of 16.7% for survivin, 16.7% for ki-67, and 92% for p63 in nondysplastic lesions. There is a positive correlation of expression among the three antibodies. In the association of immunoreactivity, in both dysplastic and nondysplastic lesions, increased expression of survivin reflects on the increased expression of ki-67, and there is an overexpression of p63. In leukoplakia, the expression of survivin associated with that of ki-67 reinforces the assumption that all these lesions are potentially malignant, regardless of histopathology; and the overexpression of p63 may indicate carcinogenic potential. These findings may help in the treatment of patients with this type of lesion.

The differential diagnosis of narrow band imaging for the leukoplakia lesion on the vocal cord

The differential diagnosis of narrow band imaging for the leukoplakia lesion on the vocal cord

Oral lesions as an important marker for HIV progression

Oral hairy leukoplakia (OHL) is a benign lesion caused by Epstein-Barr virus (EBV) replication in the oral epithelium affecting the borders of the tongue. It is strongly associated with immunosuppression, especially in HIV+ adults but is uncommon in pediatric population. The aim of the study is to show the importance of the correct diagnosis of OHL and its influence on HIV treatment.We report two cases of HIV+ adolescent patients that presented with leukoplakic lesions on the border of the tongue, suggestive of OHL. OHL diagnosis was confirmed in only one case through EBV in situ hybridization. After confirmation of the diagnosis, the patient with OHL was referred to an infectious disease specialist with the decision to start antiretroviral therapy. OHL definitive diagnosis can help clinical management of pediatric HIV+ patients.

Candida infection in oral leukoplakia: an unperceived public health problem

Objectives: The study aimed to determine the proportion, known risk factors and etiology for Candida infection in leukoplakia lesions among patients with oral leukoplakia attending the Oral and Maxillofacial Clinic at a Tertiary Care Hospital in Sri Lanka.Materials and methods: Eighty clinically suspected oral leukoplakia patients were included. Two oral swabs each, from leukoplakia patients: one swab from the lesion and the other one from the contralateral unaffected corresponding area (as a control) were collected. Direct microscopy and culture followed by colony count and phenotypic identification were performed to identify pathogenic Candida species.Results: Candida infection was seen in 47% of patients with oral leukoplakia. Candida albicans (94.7%) was the most common Candida species followed by Candida tropicalis (5.3%). Majority of Candida-infected lesions were seen in the buccal mucosa region. Alteration of taste (p = 0.021), having other oral lesions (p = 0.008), angular cheilitis (p = 0.024) and periodontitis (p = 0.041) showed a significant association with Candida-associated leukoplakia. Increasing age showed a significant tendency for Candida infection (p = 0.020). Smoking (p = 0.026) and betel-quid chewing (p = 0.006) were also found to be significantly associated, although alcohol consumption alone did not show a significant association. Oral leukoplakia patients who had all three habits: alcohol consumption, smoking and betel-quid chewing had a significant association with Candida infection (p = 0.004).Conclusions: Patients who had a combination of risk factors: smoking, betel-quid chewing and alcohol consumption were seen to have a significant association with Candida infection. Further betel-quid chewing alone and smoking singly was also significantly associated with Candida infection in oral leukoplakia.

The role of narrow-band imaging (NBI) endoscopy in optical biopsy of vocal cord leukoplakia.

The aim of this study was to investigate whether observing microvascular changes by narrow-band imaging (NBI) endoscopy in the area surrounding leukoplakia is sufficient for discriminating between benign and malignant patterns of vocal cord leukoplakia. A total of 282 patients were investigated using white-light high-definition TV laryngoscopy and NBI endoscopy from 6/2013 to 8/2015, and 63 patients with a primary case of laryngeal leukoplakia were enrolled. Patients were divided into two groups based on leukoplakia with surrounding malignant intraepithelial papillary capillary loops (group I; 26/63) and leukoplakia with a surrounding benign vascular network (group II; 37/63), both by NBI endoscopy. All 63 patients were evaluated by blinded histological examination, and results were compared with NBI optical biopsy. Carcinoma in situ or invasive squamous cell carcinoma was confirmed in 22/26 cases (84.6%) in group I. Hyperkeratosis or low-grade dysplasia was confirmed histologically in 31/37 (83.8%) and squamous cell carcinoma in 2/37 (5.4%) cases in group II. Accordance of NBI endoscopy and histopathological features of vocal cord leukoplakia lesions was statistically significant (kappa index 0.77, p<0.001), with a sensitivity of 88.0% (95% CI 67.8-97.5%) and specificity of 89.5% (95% CI 71.2-97.1%). NBI is convenient for improving evaluation of laryngeal leukoplakias based on optic prehistological diagnosis. The close accordance between NBI features and histological results suggests that a negative NBI endoscopy may be an indication for long-term endoscopy follow-up without histological evaluation.

Abstract 4324: Undenatured whey protein isolate exhibit chemopreventive activity against HPV-16 induced carcinogenesis of CD271+ oral mucosa stem cells

Abstract Oral cancer, and associated HPV-16 infection, and tobacco smoking is a major public health concern in the Kamrup district of India. To facilitate research on oral cancer chemoprevention, we have set up a collaborative research team between Forsyth Institute, an oral medicine specialized center affiliated to Harvard School of Dental Medicine, and KaviKrishna Laboratory, a non-for profit private laboratory set up located in Guwahati, the major city of Kamrup district, India. To study the cellular and molecular mechanism of HPV-16 mediated carcinogenesis, we have developed an in vitro model of HPV-16 mediated carcinogenesis of oral squamous stem cells. In this model (Bhuyan et al. The potential role of oral mucosa stem cell altruistic behavior as the initiating event of malignant transformation. AACR abstract Control # 16-A-6618-AACR), the treatment of oral mucosa cells derived from healthy volunteer with HPV-16 derived E6 protein led to expansion of a p53 deficient CD271+ expressing oral mucosa stem cells (OMSC). Noted that CD271 cell surface marker was recently identified as a putative marker for OMSCs. Using this in vitro carcinogenesis model, we evaluated the potential chemopreventive role of dietary whey protein. The E6 treated p53 deficient CD271+ cells were treated with DMEM/F12 media containing 0.2% of Immunocal, an undenatured whey protein (Tsai WY et al. Nutr Cancer 2000. PMID: 11525598). The p53 status as well as in vitro self-renewal activity of the CD271+ cells were examined by ELISA, transcriptional activity assay, and methylcellulose based clonogenic assay. We also fed Immunocal 20 gm/daily for 6 months to 5 individual with oral leukoplakia lesion with HPV-16 positivity. The CD271+ cells obtained from the leukoplakia lesion of clinical subjects were subjected to p53 status, and clonogenic assay. The data was compared with CD271+ cells obtained from leukoplakia lesion of subjects taking regular diet without whey protein supplements. We found that addition of Immunocal whey protein led to 8-fold decrease in the expansion of CD271+ cells following E6 treatment in the in vitro model of OMSC culture. Importantly, Immunocal treatment prevented the suppression of p53 in OMSCs. In the preliminary clinical study, the dietary intake of Immunocal led to complete loss of leukoplakia lesion in the 4/5 individual. In contrast, the control subjects exhibited the presence of CD271+ cells in the leukoplakia lesion having low p53 status, and high clonogenic activity. We are incorporating a larger number of subjects to study the potential chemopreventive activity of whey protein, using the locally available affordable whey protein extracts. Conclusion: This study indicate that whey protein extract, which is available in the local villages of Kamrup district could serve as a chemopreventive agent against oral cancer. Citation Format: Sora Sandhya, Rika Tsuchida, Sukanya Gayan, Rashmi Bhuyan, Joyeeta Talukdar, Bidisha Pal, Seema Bhuyan, Jugal Ch Das, Amal Ch Kataki, Debabrata Baishya, Bikul Das. Undenatured whey protein isolate exhibit chemopreventive activity against HPV-16 induced carcinogenesis of CD271+ oral mucosa stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4324.

Correlation analysis of oral lesion sizes by various standardized criteria

ObjectiveRequirements of an NCI contract examining a novel treatment for leukoplakia were to compare standard bi-dimensional measurement of oral lesions to examine for correlation with Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and to examine the feasibility of digital image analysis for automated measurements. Study designRetrospective review. MethodsWe examined 13 patients by bi-dimensional measurement and compared these measurements to 1) RECIST criteria, 2) scalar digital measurements using a standardized measuring device within the photograph, and 3) pixel number. ResultsRECIST criteria correlated (r-squared=0.8535, p<0.0001) with bi-dimensional measurements. Digitized measures in photographs correlated with bi-dimensional measurements (r-squared=0.6661, p=0.0007), but were time consuming. There was minimal to no correlation between pixel number in Adobe Photoshop and the other measures. ConclusionBi-dimensional measurement of oral leukoplakia and RECIST criteria are highly correlated. Digital photography measurements, though highly correlative, are very cumbersome. We recommend bi-dimensional or longest length measurement and a simple photograph as standard of documentation for leukoplakia lesions.

Peroxiredoxin 1 has an anti-apoptotic role via apoptosis signal-regulating kinase 1 and p38 activation in mouse models with oral precancerous lesions.

Peroxiredoxin 1 (Prx1) is important in the protection of cells from oxidative damage and the regulation of cell proliferation and apoptosis. Prx1 is overexpressed in oral precancerous lesions of oral leukoplakia (OLK) and oral cancer; however, the association between Prx1 expression and OLK pathogenesis remains unknown. The present study investigated the role of Prx1 and its molecular mechanisms in oxidative stress-induced apoptosis during the pathogenesis of OLK. Wild-type and Prx1 knockout mice were treated with 50 µg/ml 4-nitroquinoline-1-oxide (4NQO) or 4NQO + H2O2 for 16 weeks to establish mouse models with tongue precancerous lesions. Apoptotic cells were detected using terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The expression of Prx1, apoptosis signal-regulating kinase 1 (ASK1), phosphor-ASK1, p38 and phosphor-p38 was analyzed using immunohistochemical staining, and their mRNA expression levels were evaluated by reverse transcription quantitative polymerase chain reaction. The present results demonstrated that 4NQO or 4NQO + H2O2 induced the development of tongue precancerous lesions in Prx1 knockout and wild-type mice. Prx1 was overexpressed in tongue precancerous lesions compared with normal tongue mucosa. There was a significant decrease in the degree of moderate or severe epithelial dysplasia, and mild epithelial dysplasia was clearly elevated, in Prx1 knockout mice treated with 4NQO + H2O2 compared with wild-type mice treated with 4NQO + H2O2. Prx1 suppressed apoptosis and upregulated phosphor-ASK1 and phosphor-p38 expression in tongue precancerous lesions. The present results suggest that Prx1 suppresses oxidative stress-induced apoptosis via the ASK1/p38 signalling pathway in mouse tongue precancerous lesions. In conclusion, Prx1 and H2O2 have a coordination role in promoting the progression of tongue precancerous mucosa lesions. The present findings provide novel insight into Prx1 function and the mechanisms of Prx1 in OLK pathogenesis.

The presence of Helicobacter pylori in oral cavities of patients with leukoplakia and oral lichen planus.

ABSTRACTObjective Helicobacter pylori infection is one of the most common bacterial infections in men. This gastrointestinal pathogen is closely related to gastritis, peptic ulcers, and the increased risk of gastric cancer. Numerous studies have indicated oral cavities as possible Helicobacter pylori reservoirs. Helicobacter pylori has been detected both in supragingival and subgingival plaques, and also in saliva. In addition, the relationship between lesions of oral mucosa and the presence of H. pylori has been evaluated and described in some studies. The aim of this study was to assess the presence of Helicobacter pylori DNA in the oral cavity of patients with oral leukoplakia and oral lichen planus.Material and Methods The study included 54 patients with oral leukoplakia, 72 with oral lichen planus lesions, and 40 healthy controls. The presence of Helicobacter pylori in oral cavity samples was analyzed using a single-step Polymerase Chain Reaction (PCR) method. All patients underwent a periodontal examination and the following clinical parameters were collected: pocket depth, bleeding, and plaque indexes. The periodontal status was assessed using the Offenbacher classification.Results In most patients, pathological lesions were in typical sites on the buccal mucosa (leukoplakia in 88%, and oral lichen planus in 93% of patients). The DNA of the Helicobacter pylori was present in 20% of patients with leukoplakia and 23% of patients with lichen planus. We did not find the DNA of H. pylori in healthy controls. The periodontal status described by periodontal indices was worse in the investigated group than in the control group.Conclusion These findings suggest that the H. pylori presence in oral cavities may be related with leukoplakia and lichen planus oral lesions.

Photodynamic Therapy - A Non-invasive Treatment Modality for Precancerous Lesions.

Oral premalignant lesions are conditions having high potential tendency for transformation into malignancy. The use of a conservative and effective treatment modality is one of the best strategies for cancer prevention. Photodynamic therapy (PDT) is a non-invasive method for topical and selective treatment of oral precancerous lesions. The present study was taken up to determine the efficacy of PDT in oral precancerous lesions. The study consisted 13 patients with 24 oral leukoplakia (OL) lesions and 8 with 20 oral lichen planus (OLP) lesions, divided into control and study groups. These lesions were affecting various intraoral sites, the buccal mucosa being the most common site followed by tongue and gingiva. The treatment regimen of PDT included 98% 5-aminolevulinic acid (5-ALA) which is topical applied and irradiated with light emitting diode (LED) of 420 nm wavelengths at several sessions. In OL 16.6% of cases showed complete response, 66.6% partial response and 16.6% no response of the lesions to the treatment. In OLP 80% and 20% of the lesions showed partial and no response respectively. The differences with control groups for OL + OLP were found to be significant (P < 0.001). Based on the results of the present study, we can conclude that PDT appears to be a feasible alternative to conventional therapy for oral premalignant lesions.