Mild Oral Epithelial Dysplasia Research Articles

P53 Abnormal Oral Epithelial Dysplasias are Associated With High Risks of Progression and Local Recurrence—A Retrospective Study in a Longitudinal Cohort

Grading of oral epithelial dysplasia (OED) can be challenging with considerable intraobserver and interobserver variability. Abnormal immunohistochemical staining patterns of the tumor suppressor protein, p53, have been recently shown to be potentially associated with progression in OED. We retrospectively identified 214 oral biopsies from 203 patients recruited in a longitudinal study between 2001 and 2008 with a diagnosis of reactive, nondysplastic lesions, low-grade lesions (mild OED and moderate OED) and high-grade lesions (HGLs; severe OED/carcinoma in situ). Tissue microarrays were constructed from the most representative area of the pathology. Three consecutive sections were sectioned and stained for hematoxylin and eosin, p53 immunohistochemistry, and p16 immunohistochemistry. The staining results were reviewed by 2 pathologists (Y.C.K.K., C.F.P.) blinded to clinical outcome. Samples were categorized into p53 abnormal OED (n = 46), p53 conventional OED (n = 118), and p53 human papillomavirus (HPV) OED (HPV associated) (n = 12) using a previously published pattern-based approach. All cases of p53 HPV OED (HPV associated) were identified in HGLs. In contrast, cases of p53 abnormal OED were observed in mild OED (9.5%), moderate OED (23%), and severe OED/carcinoma in situ (51%). None of the 27 reactive or nondysplastic lesions showed abnormal p53 staining patterns. Among the 135 low-grade lesions, 23 cases (17.0%; 2 mild OEDs and 21 moderate OEDs) progressed to HGL or squamous cell carcinoma, with 11 cases showing progression within the first 3 years. Remarkably, 82% (9/11) of these faster progressors showed abnormal p53 patterns. Survival analysis revealed that p53 abnormal OED had significantly poorer progression-free probability (P < .0001) with hazard ratio of 11.24 (95% CI, 4.26-29.66) compared with p53 conventional OED. Furthermore, p53 abnormal OED had poorer local recurrence–free survival compared with p53 wild-type OED (P = .03). The study supports that OED with p53 abnormal pattern is at high risk for progression and recurrence independent of the dysplasia grade.

Expression of PD-L1 and p-RPS6 in epithelial dysplasia and squamous cell carcinoma of the oral cavity.

Oral squamous cell carcinoma (OSCC) is often preceded by oral epithelial dysplasia (OED). The role of ribosomal protein S6 (RPS6) and programmed cell death ligand-1 (PD-L1) in the progression of OED to OSCC remains unclear. This study aimed to investigate the expression of phosphorylated RPS6 (p-RPS6) and PD-L1 in OSCC and OED and to examine its relationship with clinicopathological features. Fifty-two OSCC and 48 OED cases were recruited for immunohistochemical analysis of p-RPS6 and PD-L1 expression. The expression of markers was correlated with clinicopathological features of OSCC and OED. We found p-RPS6 expression in all cases of OSCC and OED, whereas PD-L1 was expressed in 42/48 (87%) OED and in 28/52 (53%) OSCC. The patients with mild OED presented higher expression level of PD-L1 and p-RPS6 significantly, when compared to moderate-differentiated OSCC patients (p < 0.05). Moreover, we found a significant positive correlation between PD-L1 and p-RPS6 expression in OED and OSCC patients (p < 0.01). The PD-L1 expression was significantly related to more than 2 cm tumor size in OSCC patients (p = 0.007). Our findings suggest the upregulation of PD-L1 may be related with activation of the mTOR pathway in the early events of tumor progression and the pathogenesis of OSCC.

Oral health of an indigenous population in northeastern Brazil: a cross-sectional Study of the Fulni-ô ethnic group.

There is a lack of studies evaluating the oral health of traditional indigenous communities in Brazil. Thus, the objective of this study was to describe the oral health characteristics of the indigenous Fulni-ô ethnic group in Northeast Brazil. A cross-sectional observational investigation was conducted within the Project on Atherosclerosis among Indigenous Populations. This study included participants of both sexes from the Fulni-ô ethnic group. The participants included in this investigation underwent a comprehensive oral health evaluation by a registered and experienced dentist to assess oral health and identify potentially malignant oral lesions. Participants with suspicious lesions were referred for biopsy. Shapiro-Wilk, Mann-Whitney, and Student's t-tests were used, and measures of central tendency and dispersion were described. Statistical significance was 5%. A total of 104 individuals were included in this study. The prevalence of the use of tobacco derivatives was 94.0%, with similarities between sexes. The prevalence of oral changes in this study population was 84.4%. Fifty-one individuals who underwent oral reassessment were referred for oral lesion biopsy. This study demonstrated a high prevalence of oral alterations in the Fulni-ô population. Histopathological analyses indicated the presence of mild oral epithelial dysplasia in five cases.

Assessment of the Relationship between Expressions of CD34, p63 with Different Clinical Types of Oral Epithelial Dysplasia: A Retrospective Immunohistochemical Study

Background: Potentially malignant disorders such as leukoplakia and erythroplakia are often associated with dysplastic changes that have an increased risk for malignant transformation. CD34 is considered as an important marker for tissue vascularization, which represents microvessel density. P63 has a role in epithelial proliferation and is frequently altered in dysplasia and associated with tumorigenesis. The aim of this study was to evaluate the expression of CD34 and p63 in different grades of oral epithelial dysplasia (OED). Methods and Results: This research included 50 histopathologically confirmed OED. CD34 and P63 expressions were studied by using the immunohistochemical technique. Most OED lesions were observed in patient between 40 and 69 years of age. Buccal mucosa was the most affected site (42%). According to histopathological grades, mild OED was predominant (54%). There was a significant difference among OED grades through the P63 marker. Conclusion: The P63 marker can be considered a good indicator for malignant transformation by grade scoring scales, and the CD34 marker can be used as a useful diagnostic indicator for OED.

Expression of Orai1 and STIM1 in human oral squamous cell carcinogenesis

Background/purposeReturn of Ca2+ to endoplasmic reticulum is mediated by Orai/STIM-mediated store-operated Ca2+ entry (SOCE) channel. We aimed to investigate Orai1 and STIM1 expressions in human oral carcinogenesis. Materials and methodsSixty-six oral squamous cell carcinomas (OSCCs), 14 oral potentially malignant disorders (OPMD) with moderate-severe oral epithelial dysplasia (OED), 19 OPMD with mild OED, and 14 normal oral mucosa (NOM) samples were subjected to immunohistochemical staining. Two human oral cancer cell lines (OCCLs), an oral premalignant cell line (DOK), and a normal oral keratinocyte culture (HOK) were used for Western blot and real-time quantitative reverse transcription-polymerase chain reaction. OCCLs were evaluated for proliferation, migration, and invasion assays. ResultsOrai1 and STIM1 protein and mRNA expressions in OSCC were significantly enhanced as compared with normal samples. Protein expressions of Orai1 and STIM1 in OCCLs were significantly enhanced as compared with HOK. Significant decreases in degrees of proliferation, migration and invasion were noted in OCCLs with Orai1 and STIM1 siRNA transfection as compared with those without transfection. Significantly increased Orai1 and STIM1 protein levels were noted in OPMD with moderate-severe OED as compared with those with mild OED. ConclusionOur results indicate that Orai1 and STIM1 overexpression is associated with human oral carcinogenesis.

An Immunohistochemical Study of HIF-1 Alpha in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma.

To evaluate and compare the expression of HIF-1 Alpha (HIF-1α) in oral epithelial dysplasia (OED) and various grades of Oral squamous cell carcinoma (OSCC). 30 cases each of OEDand OSCC were stained with HIF-1α antibody. Quantification of HIF-1α positive cellswas carried out and the data was statistically analysed. The mean % HIF-1α labeling index (HIF-1α LI) increased significantly from mild OED (32.11%), moderate OED (55.07%), to severe OED (64.58%). There was a statistically significant increase in the expression of HIF-1α as grades of OED increased. The mean HIF-1α LI % in well differentiated OSCC was 46.3%, Moderately differentiated OSCC-76.31% and Poorly differentiated OSCC-89.9%. The mean HIF-1α LI was found to increase with increasing grades of OSCC which was statistically significant (P < 0.05). Further a comparison of mean HIF-1α LI in OED with different histologic grades of OSCC by Independent samples t test was performed. We found statistically significant difference between OED and moderately differentiated OSCC and OED and poorly differentiated OSCC (P = 0.000). Progressive increase in expression of HIF-1α was noted from OED to OSCC. It can be postulated that epithelial dysplastic lesions with increased HIF-1α expression are at greater risk of malignant transformation, suggesting that the expression of HIF-1α is an early event in oral carcinogenesis.

Coalition of E-cadherin and vascular endothelial growth factor expression in predicting malignant transformation in common oral potentially malignant disorders.

Background:Reduced E-cadherin expression and increased VEGF expression is known to be involved in tissue growth and transformation of Oral Potentially Malignant Disorders (OPMDs) and has been correlated with their differing histological grades in numerous studies.Aim:To evaluate Immunohistochemical (IHC) expression of both E-cadherin and VEGF in predicting the malignant transformation potential of common OPMDs.Materials and Methods:Ten cases each of Normal Oral mucosa (NOM), Mild Oral Epithelial Dysplasia (OED), Moderate OED, Severe OED, Oral Submucous Fibrosis, (OSMF) and Oral Squamous Cell Carcinoma (OSCC) were stained and evaluated for the expression of Ecadherin and VEGF. Quick score (QS) for expression intensity in all epithelial layers was calculated for both markers and results statistically analysed using Kruskal –Wallis ANOVA and Mann-Whitney “U” test.Results:E-cadherin expression was continuous and membranous in all the layers of NOM and reduced with progressing grades of OED to OSCC. In OSMF, expression was intermediate between moderate and severe OED. VEGF expression increased as the disease progressed from normal to increasing grades of OED to malignancy. In OSMF, expression was similar to that in mild OED. VEGF, E-cadherin expression for basal and parabasilar cells showed a strong statistically significant negative correlation in NOM. A very strong statistically significant positive correlation with perfect monotonic relation was noted in superficial cells in severe OED group and OSCC group.Conclusion:E-Cadherin and VEGF could be used as combination markers to predict the potential risk for malignant transformation in OEDs.

THE COMPARISON OF P53 EXPRESSION PATTERNS IN NORMAL AND DYSPLASTIC ORAL MUCOSA

Current diagnostic criteria for oral epithelial dysplasia (OED) mostly rely on cytologic and architectural alterations, and these sometimes are not sufficient to distinguish reactive atypia from mild OED. Wild-type p53 protein has been shown to be present in approximately 25% of the basal cell nuclei in normal oral mucosa. In OED, basal and suprabasal p53 overexpression has been noted. We hypothesize that p53 may help to differentiate OED and reactive keratoses, and improve the accuracy of histopathologic diagnosis.

THE EFFECT OF OXIDATIVE STRESS ON MITOCHONDRIAL ULTRASTRUCTURE AND IMMUNOEXPRESSION OF ERK-1 AND HIF-1 ALPHA IN ORAL EPITHELIAL DYSPLASIA INDUCED IN EXPERIMENTAL ANIMALS

Background: Oxidative stress and accumulation of reactive oxygen species may play a role in the pathogenesis of cancer. They were reported in precancerous and cancerous cells. Methods: An animal model of carcinogenesis was used to detect the effect of oxidative stress on mitochondrial ultrastructure by transmission electron microscope and the levels of extracellular signal- regulated kinase-1(ERK-1) and hypoxia inducible factor-1 alpha (HIF-1α) by immunohistochemistry in mild and severe oral epithelial dysplasia (OED) induced in tongues of experimental mice. Results: We identified degeneration and enlargement of mitochondria in association with up- regulation of both ERK-1 and HIF-1α from normal control to mild OED and reached their highest values in severe OED. Conclusions: Degeneration and enlargement of mitochondria in association with up-regulation of both ERK-1 and HIF-1α can be indicative features of dysplastic changes and may act as early markers for malignancy.

Overexpression of Smad proteins, especially Smad7, in oral epithelial dysplasias

Transforming growth factor β, via membrane-bound receptors and downstream Smad2-4, 7, can modulate tumorigenesis. Smad2 and Smad3 heterodimerize with Smad4, and the complex migrates to the nucleus to regulate the expression of target genes. Smad7 is a key negative regulator of this signaling pathway. This study aimed to examine Smad2-4, 7 expression and phosphorylated Smad2-3 (p-Smad2-3) in oral epithelial dysplasia and compared it with normal oral mucosa, hyperkeratosis/epithelial hyperplasia and squamous cell carcinoma (SCC). Immunohistochemical staining of Smad2-4, 7 and p-Smad2-3, was performed for 75 samples of human oral mucosa, including hyperkeratosis/epithelial hyperplasia (n = 20), mild epithelial dysplasia (n = 11), moderate to severe epithelial dysplasia (n = 11), and SCC (n = 43). Normal buccal mucosa samples (n = 9) were also included. A significant increase in Smad7 expression was observed in the ascending order of samples of normal oral mucosa, hyperkeratosis/epithelial hyperplasia/mild oral epithelial dysplasia, moderate to severe oral epithelial dysplasia, and well-differentiated oral SCC/moderately to poorly differentiated oral SCC. Additionally, significant increases in Smad7 expression were noted as compared with expression of Smad2-4 and p-Smad2-3 in lesions of hyperkeratosis/epithelial hyperplasia, mild oral epithelial dysplasia, moderate to severe oral epithelial dysplasia, well-differentiated oral SCC, and moderately to poorly differentiated oral SCC. Our results indicate that Smad proteins, particularly Smad7, in oral epithelial dysplasia and SCC could contribute to the attenuation of Smads anti-proliferative signaling in cancer development. Smad7 could be a marker for risk of malignant transformation of oral epithelial dysplasia.

Oral lichen planus shows higher expressions of tumor suppressor gene products of p53 and p21 compared to oral mucositis. An immunohistochemical study

Objective Oral lichen planus (OLP) has been speculated to be a chronic inflammatory disease with potential for malignant progression. The aim of this study was to establish a hypothesis on the difference between OLP and oral mucositis (OM) in terms of tumor suppressor gene expression. Design Computer based image analysis of immunohistochemical expressions of p53 and p21 was investigated in 18 samples of OLP, 10 normal oral epithelium (NOE), 10 oral squamous cell carcinoma (OSCC), 13 OM, 20 oral focal keratosis (OFK), and 30 samples of oral epithelial dysplasia (OED). Representative fields were digitized and analyzed. Results Using independent samples Student's t-test, p53 and p21 the mean percentages of positive nuclei (MPPN) of p53 (40.27%) and of p21 (39.98%) in OLP were significantly higher than that of NOE, OFK and OM (15.06%, 27.87%, 30.08% and 16%, 31.09%, 33.92% respectively, p < 0.001). MPPN of p53 in OLP was not different from that of mild OED (40.5%, p = 0.85) but lower than of moderate and severe OED, and OSCC (49.78%, 61.36%, 78.16% respectively; p < 0.001). MPPN of p21 in OLP was lower than that of moderate and severe OED, and OSCC (47.72%, 57.9%, 85.44% respectively; p < 0.001) but slightly higher than that of mild OED (39.86% p = 0.81). Conclusions As the expression of p53 and p21 in OLP was significantly higher than that of oral mucositis with no significant difference from mild epithelial dysplasia, OLP might need to be followed up and monitored more closely to detect early features of transformation, if any, compared to non-specific oral mucositis which needs no close follow-up.

Alterations in the immunoexpression of claudin-1 between different grades of oral epithelial dysplasias

Claudins are transmembrane proteins that play a role in cell proliferation and adhesion and tumourigenesis. This study evaluated the immunoexpression of claudin-1 in the oral epithelial dysplasia (OED) (19 mild, 26 moderate, 3 severe). Diffuse staining predominated in mild (89.4%) and moderate (80.8%) OEDs. Immunoexpression in the middle and upper third was observed in all mild cases, whereas in moderate/severe dysplasias staining was observed in the upper third in 41.4% of cases, in the upper and middle third in 41.4%, and in the upper, middle and lower third in 17.2% (P<0.05). All mild OEDs and 73.1% of moderate cases presented only membrane staining, whereas membrane/cytoplasmic staining was observed in severe cases. Staining intensity was weak in 60% of parakeratinized OEDs and moderate/strong in orthokeratinized OEDs (60.8%) (P>0.05). The differences in the immunoexpression of claudin-1 between different grades of OEDs suggest the involvement of this protein in the progression of dysplasias.

Outcome of oral dysplasia: a retrospective hospital‐based study of 207 patients with a long follow‐up

The aim of this retrospective hospital-based study was to review and evaluate the long-term outcome of patients with oral epithelial dysplasia (OED), with or without surgical intervention, to identify factors affecting clinical course and malignant evolution. Patients with a follow-up of at least 12 months were included. Data collected were statistically analyzed. The mean age was 63.58 years for women (n = 100) and 64.17 years for men (n = 107). One hundred and thirty-five of the patients had lesions with histopathological features of mild OED, 50 had moderate OED and 22 had severe OED. Gender and risk factors seemed not to be related with the development of OED. One hundred and thirty-three patients underwent active treatment. During the period considered, 39.4% of the 207 lesions disappeared; 19.66% remained stable and 33.7% of the total cases showed a new dysplastic event after treatment. Fifteen (7.24%) out of 207 developed a squamous cell carcinoma during follow-up. Our data showed that speckled lesions are more often associated with high histological grade. The risk of malignant development does not seem to be predictable. Surrounded by the limitations of the retrospective designs, we have showed that there is no eminent benefit of surgical intervention of OED in preventing recurrences and malignant development.

Cell proliferation and p53 expression in pseudoepitheliomatous hyperplasia of oral paracoccidioidomycosis

Paracoccidioidomycosis (PCMycosis) is a systemic mycosis frequently found in many regions of Latin America. Microscopically, it is characterised by granulomatous inflammation and pseudoepitheliomatous hyperplasia (PEH). This work describes the proliferation index and p53 expression by immunohistochemistry in PEH of PCMycosis, normal oral mucosa (NOM) and mild oral epithelial dysplasia (ED). Ki67 positive cells were present in the basal and parabasal layers in NOM and PEH, while in ED it was also observed in the spinous layer. Percentage of ki67 positive cells was 7.7, 28.2 and 46.0 in NOM, PEH and ED respectively. p53 was negative in NOM and in PEH it was expressed by few cells in the basal layer of only three cases. However, it was expressed in all cases of ED, in basal and parabasal layers. Although histologically PEH mimics well-differentiated squamous cell carcinoma, its proliferative pattern and p53 expression are more similar to NOM than to dysplasia. These findings, confirm PEH as a reactive process probably associated with the underlying chronic inflammation.

Oral epithelial dysplasia: clinical characteristics of western European residents

To detail the clinical presentation of oral epithelial dysplasia in a large cohort of residents in western Europe. Descriptive statistical analysis of the data were calculated using chi-square and Fisher’s exact tests. Oral epithelial dysplasia manifested typically as a white or mixed red and white lesion on the tongue, buccal mucosa or floor of mouth. The peak age of presentation of oral epithelial dysplasia was the 6th decade. Most clinically detected lesions had only mild oral epithelial dysplasia. Although uncommon, lesions with severe dysplasia were most likely to arise on the floor of mouth or lateral border of tongue. Oral epithelial dysplasia is likely to manifest as a solitary white patch, but it is not possible to accurately predict the likely degree of dysplasia from the clinical features of such lesions.

Expression of inducible nitric oxide synthase in human oral premalignant epithelial lesions

Increased expression of inducible nitric oxide synthase (iNOS) has been found at the protein level in human oral epithelial dysplasias, but, a corresponding expression at the mRNA level has not been demonstrated. The purpose here was to assess the expression of iNOS mRNA and its correlation with the expression of the enzyme protein in human buccal premalignant epithelial lesions. Activities for iNOS protein (57/80, 64%) and mRNA (53/80, 53%) were detected in the specimens examined. Cytoplasmic and/or nuclear staining for iNOS protein was detected immunohistochemically in a number of mild oral epithelial dysplasias (16/20, 80%), moderate to severe oral epithelial dysplasias (14/20, 70%), submucous fibrosis (14/20, 70%) and verrucous hyperplasia (13/20, 65%). Upon in situ reverse transcription-polymerase chain reaction (RT-PCR), the cellular location of iNOS mRNA was compatible with the immunohistochemical findings. Furthermore, iNOS mRNA was found in 15 specimens of mild oral epithelial dysplasia (15/20, 75%), 13 specimens of moderate to severe oral epithelial dysplasia (13/20, 65%), 13 specimens of submucous fibrosis (13/20, 65%) and 12 specimens of verrucous hyperplasia (12/20, 60%). No iNOS protein or mRNA was found in samples of normal buccal mucosa, or in negative controls. Further studies on the characteristics of iNOS-positive cells and more long-term clinical follow-up data are needed.

Evaluation of glutathione S-transferase activity in human buccal epithelial dysplasias and squamous cell carcinomas

Glutathione S-transferase (GST) activity and amount of GST α, μ and π isoforms were measured in 40 patients with histopathologically confirmed oral epithelial dysplasia (OED) and squamous cell carcinoma of buccal mucosa. The results were compared with those of normal mucosa in an equal number of age- and sex-matched healthy controls. Mean total GST activities were significantly elevated from normal buccal mucosa for mild OED, moderate OED, severe OED and squamous cell carcinoma. GST activity of value approximating 100 nmol/min/mg distinguished between normal and dysplasia, and of value about 400 nmol/min/mg delineated between dysplasia and squamous cell carcinoma were observed. GST π was the predominant class in both the diseased and normal buccal mucosa examined. This class π GST was present at an intracellular concentration, which was significantly higher in diseased buccal mucosa than in normal buccal mucosa. These results indicated that π class GST was the major form of this enzyme in the cytosolic fraction of oral mucosa. The severity of OED related to squamous cell carcinoma development seemed to increase concomitantly with an increase in the level of this enzyme. Further studies will validate the role of GST π estimation in predicting the potential malignancy of OED.