Sequential immunohistochemical p53 expression in biopsies of oral lichen planus undergoing malignant evolution

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

Investigating the factors proposed in oral lichen planus malignant transformation: A literature review

Background and Aims

Lichen planus is a chronic inflammatory disease that affects about 1% of the world's population. The World Health Organization has included oral lichen planus among potentially malignant disorders. Identification of reliable biomarkers for the diagnosis of malignant transformation may play a unique role in the development of standard screening and improvement of follow-up in patients with oral precancerous lesions. It is currently assumed that the molecular pathways controlling growth, maturation, proliferation, and apoptosis in epithelial cells may play an important role in the process of transformation into malignancy.

Methods

The search was done in PubMed, Scopus, Google Scholar, Embase, and Cochrane databases from 1960 to 2022.

Results

Based on the inclusion criteria, 23 articles were included.

Conclusion

In this review of articles, 34 different biomarkers that have been investigated in studies for the possibility of malignant transformation in OLP have been studied. Among all the risk factors related to malignant transformation, most studies have been done on the role of cytokines and tumor suppressors, in fact, the chronicity of the lesion which is the result of the reaction between the repair and the inflammatory response and the responses accompanied by the secretion of cytokines, may play a major role in the malignant transformation of OLP.

The genomic and proteomic landscape in oral lichen planus versus oral squamous cell carcinoma: a scoping review

BACKGROUND

Oral lichen planus (OLP), a World Health Organization (WHO)-classified oral potentially malignant condition, confers a 1% risk of transformation to oral squamous cell carcinoma (OSCC). There does not appear to be a consensus understanding of the underlying molecular events. This scoping review aimed to identify critical molecular pathways and highlight gaps in existing knowledge on malignant transformation in OLP.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) guidelines, a comprehensive literature search and methodical screening identified 61 relevant studies detailing molecular differences between OLP and OSCC.

RESULTS

Molecular changes shared between OLP and OSCC included those affecting cellular proliferation (altered p53 expression, hypermethylation of p16/CDKN2A, MYC gains, increased ki-67), apoptosis (increased bcl-2 and survivin expression), extracellular matrix (ECM) remodeling (increased matrix metalloproteinase [MMP] expression), and transcriptional control (altered bmi1 and microRNA [miRNA] expression). In addition, some molecular alterations accumulated incrementally from control to OLP to OSCC or were present in higher-risk erosive variants of OLP or transformed OLP. Few studies included rigorous diagnostic inclusion criteria or unbiased discovery methods.

CONCLUSIONS

Results of this review support the potentially malignant nature of OLP and imply that molecular events associated with malignant transformation may be heterogeneous. In addition, findings in this review highlight the need for additional studies using rigorous diagnostic inclusion criteria and unbiased discovery methods to further understand this process.

Markers associated with malignant transformation of oral lichen planus: A review article

Oral lichen planus (OLP) is one of the autoimmune diseases associated with chronic inflammation that involves several complications including the potential for malignant transformation into oral squamous cell carcinoma. Pathogenesis of OLP are yet to be fully comprehended however, it has been demonstrated that the epithelial cells in OLP lesions are affected by cytotoxic T lymphocytes leading to immunological reactions. Various factors are reported to act as diagnostic markers for predicting and monitoring the cancerous progression. Hence, in this review, we summarize and present the latest studies regarding the predictive markers associated with malignant potential of OLP.

Comparison of p53 immunohistochemical staining in differentiated vulvar intraepithelial neoplasia (dVIN) with that in inflammatory dermatoses and benign squamous lesions in the vulva

AIMS

Differentiated vulvar intraepithelial neoplasia (dVIN), the precursor lesion to human papillomavirus-independent vulvar squamous cell carcinoma (VSCC), can be difficult to distinguish from vulvar inflammatory dermatoses. Our goal was to determine if p53 could be a useful biomarker for dVIN, by characterizing p53 percentage, intensity and patterns of staining in dVIN and its histological mimics.

METHODS AND RESULTS

We studied p53 immunohistochemical staining patterns in 16 dVIN cases and 46 vulvar non-neoplastic squamous lesions [12 lichen sclerosus (LS); seven lichen simplex chronicus; three lichen planus (LP); six psoriasis; 13 spongiotic dermatitis (SPO); and five candidiasis]. dVIN cases were adjacent to a p16-negative invasive VSCC in resection specimens. All dVIN cases showed null-type or moderate to strong uniform p53 staining in >70% of basal cells, with moderate to strong continuous parabasal staining extending to two-thirds of the epidermis. This was in contrast to weak or weak to moderate patchy p53 staining in the majority of other lesions. Moderate to strong and increased basal p53 staining (≥70%) was also observed in a subset of LS cases (5/12, 42%), LP cases (1/3, 33%), and SPO cases (36%, 4/11); however, in all categories, this was limited to the basal layer, and any staining in the parabasal layers was patchy.

CONCLUSION

Strong and uniform p53 staining of basal cells, extending into the parabasal layers, and a complete absence of staining (null type) is useful in distinguishing dVIN from other mimics in the vulva. p53 staining of lesser intensity or quantity, particularly basal overexpression only, overlaps with that in vulvar inflammatory lesions.

Expression of Ki-67, p53, α-SMA and COX-2 in lichen planus and related lesions: A pilot study

Background

Researchers have struggled to understand the natural history of lesions presenting with both lichenoid features and epithelial dysplasia. Thus the present study was designed to differentiate between OLP, OLP with dysplasia, epithelial dysplasia and epithelial dysplasia with lichenoid features based on the expressions of ki-67, p53, COX-2, and α-SMA.

Materials and methods

Formalin-fixed paraffin-embedded archival specimens of OLP, OLP with dysplasia, epithelial dysplasia and epithelial dysplasia with lichenoid features were subjected to immunohistochemical staining with ki-67, p53, COX-2, and α-SMA.

Results

Ki-67 exhibited strong positivity in 100% (6/6) of epithelial dysplasia cases, 71.4% (5/7) of lichenoid dysplasia cases, 57.1% (4/7) of OLP cases and 60% (3/5) of OLP with dysplasia cases. Strong p53 staining was evident in more cases of lichenoid dysplasia [42.8% (3/7)], while moderate staining was more frequent in OLP cases [42.8% (3/7)] and OLP with dysplasia cases [42.8% (3/7)] and mild intensity was more frequent in epithelial dysplasia cases [50% (3/6)] followed by lichenoid dysplasia cases [42.8% (3/7)], OLP cases [28.5 (2/7)] and OLP with dysplasia cases [40% (2/5)]. COX-2 strong positivity was more frequent in cases of epithelial dysplasia cases [57.1% (4/7)] and OLP [50% (3/6)]. Strong α- SMA staining was noted more frequently in lichenoid dysplasia cases [71.4 (5/7)], followed by OLP cases [42.8% (3/7)] and OLP with dysplasia cases [60% (3/5)].

Conclusions

Ki-67, p53, α-SMA and COX-2 expression do not differentiate between OLP, LP with dysplasia and epithelial dysplasia with lichenoid features.

Markers of Oral Lichen Planus Malignant Transformation

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology with significant impact on patients' quality of life. Malignant transformation into oral squamous cell carcinoma (OSCC) is considered as one of the most serious complications of the disease; nevertheless, controversy still persists. Various factors seem to be involved in the progression of malignant transformation; however, the mechanism of this process is not fully understood yet. Molecular alterations detected in OLP samples might represent useful biomarkers for predicting and monitoring the malignant progression. In this review, we discuss various studies which highlight different molecules as ominous predictors of OLP malignant transformation.

Correlation between tissue expression of microRNA-137 and CD8 in oral lichen planus

OBJECTIVES

Oral lichen planus (OLP) is a chronic, inflammatory condition, classified by the World Health Organization as a premalignant lesion. We performed this study to evaluate the correlation between microRNA-137 (miR-137) and CD8 oral tissue expression in OLP patients.

MATERIALS AND METHODS

Twenty OLP patients [classified into three groups: (a) papular, reticular, or plaque; (b) atrophic; and (c) erosive] and 20 healthy controls were subjected to biopsy of the oral mucosa. To evaluate CD8 tissue expression, we performed immunohistochemical examination, followed by immunostaining and computerized quantification. The expression of miR-137 was evaluated using real-time quantitative PCR. We used SPSS software (version 15 for windows) to perform the statistical analysis.

RESULTS

Our analysis showed an increased tissue expression of CD8 (p < 0.01) and reduced expression of miR-137 (p < 0.001) in OLP patients, compared to the control group. Moreover, there was a statistically significant difference (p = 0.001) between OLP subgroups in terms of CD8 tissue expression [highest in erosive OLP and lowest in papular/reticular/plaque OLP]. However, these subgroups showed no significant difference (p = 0.168) in terms of miR-137 expression. A negative correlation (p < 0.05) between tissue expression of miR-137 and CD8 was noted with a varying correlation coefficient in different OLP subgroups (-0.250 in erosive OLP, -0.491 in atrophic OLP and -0.616 in papular/reticular/plaque OLP).

CONCLUSIONS

Our findings indicate reduced expression of miR-137 and a reverse correlation between tissue expression of miR-137 and CD8 in the oral mucosa of OLP patients.

CLINICAL RELEVANCE

Future studies should investigate the therapeutic potential of miR-137 overexpression in OLP patients.

Malignant transformation of oral lichen planus and oral lichenoid lesions: A meta-analysis of 20095 patient data

OBJECTIVES

For over a century, a heated debate existed over the possibility of malignant transformation of oral lichen planus (OLP). We performed this meta-analysis to evaluate the malignant potential of OLP and oral lichenoid lesions (OLL) and investigate the possible risk factors for OLP malignant transformation into oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

We searched Medline, Scopus, and Web of Knowledge for relevant observational studies. Data on OLP malignant transformation were calculated as a pooled proportion (PP), using the Der-Simonian Liard method. We performed subgroup analyses by OLP diagnostic criteria, site, and clinical type, using Open Meta[Analyst] software. Data on possible risk factors for malignant transformation were pooled as odds ratios (ORs), using Comprehensive Meta-Analysis software.

RESULTS

Pooling data for OLP malignant transformation from 57 studies (19,676 patients) resulted in an overall PP of 1.1% [95% CI: 0.9%, 1.4%], while pooling data from 14 recent studies that used the World Health Organization-2003 diagnostic criteria resulted in an overall-PP of 0.9% [95% CI: 0.5%, 1.3%]. The risk of malignant transformation was higher (PP=2.5%, 95% CI [1%, 4%]) in OLL patients (419 patients). A significant increase of malignant transformation risk was noted among smokers (OR=2, 95% CI [1.25, 3.22]), alcoholics (OR=3.52, 95% CI [1.54, 8.03]), and HCV-infected patients (OR=5, 95% CI [1.56, 16.07]), compared to patients without these risk factors.

CONCLUSION

A small subset of OLP patients (1.1%) develop OSCC; therefore, regular follow-up for these patients is recommended. A higher incidence of malignant transformation was found among smokers, alcoholics, and HCV-infected patients; however, these associations should be further investigated.

Expression of survivin and p53 in oral lichen planus, lichenoid reaction and lichenoid dysplasia: An immunohistochemical study

Context:

The malignant transformation potential of oral lichen planus (OLP) and related lesions is a subject of great controversy.

Aim:

The aim of this study was to compare the expression of proteins related to apoptosis and tumour suppressor gene processes in OLP, oral lichenoid reaction (OLR) and oral lichenoid dysplasia (OLD).

Materials and Methods

The immunohistochemical study was carried out to investigate the expressions of survivin and p53 in a total of 30 lesional biopsy specimens - 10 cases each of OLP, OLR and OLD. The expression rates were further compared with 10 control specimens of normal oral mucosa (NORM).

Results:

Immunoreactivity for p53 was seen in 7 cases (70%) of OLD, 4 cases (40%) of OLP and 2 cases (20%) of OLR and none of NORM. We obtained a significant difference (P = 0.01) in mean p53 expression between the different entities. The positive staining rate of survivin was found to be significantly different between OLD (50%), OLP (10%), OLR (0%), and normal mucosa (0%) (P = 0.004). There was a positive correlation between p53 and survivin expression in OLP and OLD using Pearson's correlation coefficient.

Conclusion:

Lichenoid dysplasia has shown p53 and survivin expression in the range of not OLP, but leukoplakia. On the other hand, OLR seems to be an innocuous lesion. The study results with OLP are inconclusive but points toward a small but important malignant potential in OLP. This kind of comparative study highlights the importance of biopsying OLP and related lesions for proper diagnosis and appropriate management.

Diagnosis of oral lichen planus: a position paper of the American Academy of Oral and Maxillofacial Pathology

Despite being one of the most common oral mucosal diseases and recognized as early as 1866, oral lichen planus (OLP) is still a disease without a clear etiology or pathogenesis, and with uncertain premalignant potential. More research is urgently needed; however, the research material must be based on an accurate diagnosis. Accurate identification of OLP is often challenging, mandating inclusion of clinico-pathological correlation in the diagnostic process. This article summarizes current knowledge regarding OLP, discusses the challenges of making an accurate diagnosis, and proposes a new set of diagnostic criteria upon which to base future research studies. A checklist is also recommended for clinicians to provide specific information to pathologists when submitting biopsy material. The diagnostic process of OLP requires continued clinical follow-up after initial biopsy, because OLP mimics can manifest, necessitating an additional biopsy for direct immunofluorescence study and/or histopathological evaluation in order to reach a final diagnosis.

P53 and bcl-2 immunoexpression in patients with oral lichen planus and oral squamous cell carcinoma

OBJECTIVE

The aim of this study was to determine by immunohistochemistry the presence and significance of p53 and bcl-2 proteins in oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC).

STUDY DESIGN

We used 21 cases diagnosed as OLP 16 diagnosed as OSCC and four normal gingival biopsies taken from healthy patients were used as controls. Slides were processed for immunohistochemistry using anti-p53 and anti-bcl-2 monoclonal antibodies.

RESULTS

We found p53 immunoexpression in 71.4% OLP cases and 68.7% OSCC cases, with no immunoexpression in control cases. Bcl-2 was negative for all OLP and OSCC cases, and mild positivity was observed in normal tissue. We found significant correlation among p53 expression and OSCC malignancy.

CONCLUSIONS

Our results suggest that TP53 system mainly promotes a hyperproliferative state by cell cycle arrest of the OLP epithelial cells for repairing damaged DNA nor apoptosis and that anti-apoptotic action of bcl-2 is not important in this disease.

Comparative study of cell alterations in oral lichen planus and epidermoid carcinoma of the mouth mucosa

Currently, much is discussed regarding the pre-malignant nature of mouth mucosa lichen planus.

AIM

The present study aims at analyzing the alterations found in the epithelial cells present in the oral cavity lichen planus, comparing them to those found in epidermoid carcinoma.

MATERIALS AND METHODS

Histological cross-sections of oral lichen planus and epidermoid carcinoma, dyed by hematoxylineosin, were analyzed through light microscopy.

RESULT

The most frequently found alterations in oral lichen planus were: an increase in the nucleus/cytoplasm relation (93.33%), nucleus membrane thickness (86.67%) and bi-nucleus or multinucleous (86.67%). The Student t test (alpha=5%) revealed a statistically significant difference between the average number of cell alterations in oral lichen planus (5.87+/-1.57) and in epidermoid carcinoma (7.60+/-1.81). As to the types of alterations, the chi-squared test also revealed statistically significant differences among the lesions assessed in relation to the following cell alterations: nuclear excess chromatism, atypical mitoses, cellular pleomorphism and abnormal cell differentiation (p<0.05).

CONCLUSION

Despite the fact that in some cases, some pathologists may make mistakes in the histopathological diagnosis of oral lichen planus, the results obtained in this study show that the alterations present in oral lichen planus differ considerably from those seen in epidermoid carcinoma, thus showing how distinct these two diseases are.

A role for the substance P/NK-1 receptor complex in cell proliferation and apoptosis in oral lichen planus

OBJECTIVES

To determine whether substance P (SP) and NK-1 receptor (NK-1R) are expressed in oral lichen planus (OLP) and are related to cell proliferation and apoptosis in this disease.

MATERIAL AND METHODS

Tissue samples from 50 OLP patients and 26 healthy controls were studied. Immunohistochemistry was performed with anti-SP, anti-NK-1R, anti-ki-67 and anti-caspase-3 monoclonal antibodies and the clinical and pathological data of the OLP patients were evaluated.

RESULTS

With the exception of NK-1R expression in epithelial cell membrane and cytoplasm, all markers were more frequently present in OLP patients than in controls (P < 0.05). Higher cytoplasmatic expression of NK-1R was associated with higher epithelial expression of caspase-3 (P < 0.05). Higher epithelial expression of NK-1R and SP was associated with higher suprabasal and basal epithelial expression of ki-67 (P < 0.05 and P < 0.005, respectively).

CONCLUSIONS

Actions of the SP/NK-1R complex may contribute to the immune disorder underlying OLP and trigger stimuli to induce cell proliferation. These results indicate that this complex might play a role in the malignant transformation of OLP.

Carriage rate and virulence attributes of oral Candida albicans isolates from patients with oral lichen planus: a study in an ethnic Chinese cohort

The objectives of this study are to investigate the carriage rate of Candida albicans from the patients with oral lichen planus (OLP, erosive and non-erosive subtypes) and the healthy control individuals in a Chinese cohort and then to compare the virulence attributes of these isolates. Oral C. albicans isolates from 300 patients with OLP as well as 128 healthy controls were isolated and a total of 112 isolates from patients with erosive OLP (62), non-erosive OLP (24) and healthy control (26) were screened for phospholipase activity by using an in vitro plate assay method. Adhesion ability of the above isolates was also studied by using buccal epithelial cells assay. Statistically, the carriage rate of C. albicans from the patients with erosive OLP (44.29%) was higher than that of patients with non-erosive OLP (15.00%) or the healthy control group (20.31%) (P < 0.001). The adhesion to buccal epithelial cells of the isolates from the erosive OLP group (3.950 +/- 1.436) was more marked (P < 0.001) than that from healthy control (2.2112 +/- 0.4833). The phospholipase activity of these isolates either from erosive (0.4170 +/- 0.029) or non-erosive OLP groups (0.4327 +/- 0.028) was higher (P < 0.001) than that from healthy controls (0.5259 +/- 0.074). Some C. albicans isolates with special virulence attributes might be co-factors, which contribute to the development of OLP, especially erosive OLP.

Oral lichen planus: controversies surrounding malignant transformation

Studies of the malignant potential of oral lichen planus (OLP) have been hampered by inconsistencies in the diagnostic criteria used for OLP, the criteria adopted to identify a true case of malignant transformation in OLP, the risk factors for malignant transformation and the optimum management of patients to ensure the early diagnosis of transformation. Consensus remains elusive, and leading workers in this field have recently published conflicting reports on the malignant potential of OLP and on the important question of the advisability of excluding patients with epithelial dysplasia or a tobacco habit from studies on this issue. The present review outlines these debates and proposes a possible a molecular basis for the malignant transformation in this disease.

No differences in caspase-3 and Bax expression in atrophic-erosive vs. reticular oral lichen planus

BACKGROUND

Caspase-3 (CPP32) and Bax expression levels in oral lichen planus (OLP) lesions are considered reliable markers of apoptosis. The malignant transformation of OLP remains a very controversial matter. The objective of this study was to compare histological and apoptotic phenomena between atrophic-erosive and reticular forms of OLP.

METHODS

Analysis was conducted of biopsy samples from 18 patients with reticular and 14 with atrophic-erosive OLP. Conventional histology techniques were used to quantify histological markers of OLP and peroxidase/anti-peroxidase techniques to determine apoptosis markers caspase-3 (CPP32) and Bax.

RESULTS

More Civatte bodies and lymphocyte exocytosis were observed in atrophic-erosive than reticular OLP samples, without any statistical difference. No statistical significant differences in caspase-3 expression were found between these OLP forms in suprabasal layer (58.3% vs. 43.8%), basal layer (83.3% vs. 68.8%) or infiltrate (69.2% vs. 46.6%). Bax expression was relatively infrequent, and no differences were observed between atrophic-erosive and reticular forms.

CONCLUSIONS

The low frequency of apoptotic phenomena (caspase-3 and Bax) in epithelial cells of OLP may create a favourable substrate for malignant transformation. However, there does not seem to be an association with the clinical form (atrophic-erosive or reticular).

Oro-genital lichen planus: report of two cases

Lichen planus is a common mucocutaneous disease. However, lichen planus with concomitant oral and genital involvement is a rare condition that requires multidisciplinary intervention for appropriate diagnosis. In this study, we reported two cases of oro-genital lichen planus in a man and a woman. Analyses of oral and genital lesions were clinically and histopathologically compatible with lichen planus. This description highlights the importance of patients presenting oral lichen planus be routinely required to undergo further medical examination in order to investigate putative genital mucosal involvement. These lesions have the potential to progress to neoplasia. Therefore, medical and dentistry professionals should be aware of this condition.

High proliferative activity and chromosomal instability in oral lichen planus

The study aimed to assess the proliferative activity and karyotype in Oral Lichen Planus (OLP) lesions. G-banding chromosomal analysis of short-term primary cultures, and immunohistochemical expression of Ki67 and p53 were applied in 30 consecutive OLP patients divided into two groups according to clinical presentation of the lesions, and in nine subjects as negative controls. Mean values of Ki67 and p53 expression differed significantly (P<.01) between controls and patients groups with reticular or atrophic-erosive forms of OLP, whereas there was no significant difference between the two groups of patients with reticular or atrophic-erosive lesions. Six OLP patients showed clonal chromosome alterations, four of them associated with p53 overexpression. In conclusion, OLP is characterized by a high cellular turnover in most patients irrespective of clinical disease presentation. The genetic instability found in some patients should be interpreted as a consequence of the enhanced epithelial turnover, although we cannot rule out the possibility that some of the cytogenetic non-random anomalies observed represent early steps in cancer development.

Cell cycle regulating mechanisms in oral lichen planus: Molecular bases in epithelium predisposed to malignant transformation

OBJECTIVE

Expression of p53, p21, ki-67, Bcl-2 and caspase-3 proteins in oral lichen planus (OLP) was studied to investigate cell cycle regulation mechanisms in this disease.

MATERIAL AND METHODS

Oral biopsies were obtained from 51 patients with OLP and 26 controls for immunohistochemical analysis (peroxidase antiperoxidase) to quantify expression of the proteins under study (-: 0%, +: <10%, ++: 10-25%, +++: 26-50%, ++++: >50% positive cells).

RESULTS

Basal expression of caspase-3 was negative in 22 cases (46.8%) and positive in <10% of basal cells in 22 cases (46.8%); caspase-3 expression in inflammatory infiltrate was negative in 22 cases (46.8%) and positive in <10% of lymphocytes in 20 cases (42.5%). Basal expression of Bcl-2 was negative in 35 cases (74.5%); Bcl-2 was expressed in inflammatory infiltrate in 34 cases (72.3%) and was positive in <25% of lymphocytes in 14 of these (29.7%). Basal expression of p53 and p21 was positive in 32 (67.9%) and 23 (48.8%) cases, respectively. Basal expression of ki-67 was positive in 45 cases (95.7%), of which 20 (42.5%) showed positivity in >25% of cells; ki-67 was expressed in inflammatory infiltrate in 23 cases (48.9%). Significant associations were found between basal expressions of p53 and ki-67 (p<0.001) and between Bcl-2 expression in infiltrate and basal expression of ki-67 (p<0.001). No association was observed between basal expressions of p53 and caspase-3 (p=0.08). Bcl-2 expression in infiltrate and basal expression of ki-67 were independently associated with presence of OLP.

CONCLUSIONS

Epithelial cells in OLP do not preferentially develop apoptosis but rather cycle arrest or an increased proliferation rate, which may create a suitable substrate for malignant transformation.

Evaluation of proliferative potential in oral lichen planus and oral lichenoid lesions using immunohistochemical expression of p53 and Ki67

A small proportion of cases diagnosed as oral lichen planus (OLP) and oral lichenoid lesions (OLL) can undergo malignant transformation. Some authors, however, stand that only dysplastic lichenoid lesions, not true OLP, have the potential to progress to oral squamous cell carcinoma (OSCC). The histologic diagnosis is a subjective resource and is not always accurate in differentiating OLP from OLL. Thus, this study attempted to evaluate the malignant potential of lesions diagnosed as OLP and as OLL without dysplasia. The Streptavidin-biotin method of immunohistochemistry was used for the staining with p53 and Ki67 in 22 cases of OLP and 27 cases diagnosed as OLL. Ki67 immunoexpression was not statistically different between OLP and OLL (p = 0.353), but, p53 staining showed a significant contrast (p = 0.036). A higher average of staining was detected in the group of OLP. The study showed that apparently a diagnosis of OLP or OLL makes no difference for the patient regarding malignant transformation, although in OLP p53 showed a higher index of expression, probably related to the intensity of inflammatory infiltrate.

The feasibility of monitoring NF-kappaB associated cytokines: TNF-alpha, IL-1alpha, IL-6, and IL-8 in whole saliva for the malignant transformation of oral lichen planus

Previous investigations have demonstrated that immune activation and chronic inflammation may be one of the causes of oncogenesis. A previous study from our lab has shown significant increases of NF-kappaB dependent cytokines, TNF-alpha, IL-1alpha, IL-6, and IL-8 in different oral fluids from oral lichen planus (OLP) patients. The aim of this analysis was to explore the potential of detecting these cytokines in whole unstimulated saliva (WUS) in monitoring the malignant transformation of OLP. Thirteen patients with OLP (with epithelial dysplasia), 13 cases with oral squamous cell carcinoma (OSCC), and 13 age-sex matched controls were enrolled in the study. The WUS samples were collected and the level of TNF-alpha, IL-1alpha, IL-6, and IL-8 in WUS was determined by ELISA. In moderate and severe dysplasia, the level of each cytokine was significantly higher than in control. In moderate dysplasia, TNF-alpha and IL-1alpha were significantly increased at a level without difference from OSCC, but IL-6 and IL-8 was detected at a concentration significantly lower than OSCC. In severe dysplasia, the level of TNF-alpha was also not significantly different from that of OSCC, and the level of IL-1alpha, IL-6, and IL-8 was still significantly lower than that of OSCC. The level of four cytokines between smokers and non-smokers in each group did not show a significant difference. These results indicate that the change of NF-kappaB dependent cytokines in WUS may in part reflect the malignant transformation of OLP and the analysis of these cytokines and may provide a useful, non-invasive surrogate endpoint for monitoring malignant transformation as well as the therapeutic response of OLP. This is the first in vivo study utilizing saliva to confirm preclinical data that NF-kappaB is upregulated in oral carcinogenesis.

Nitrative and oxidative DNA damage in oral lichen planus in relation to human oral carcinogenesis

Oral lichen planus (OLP) is a chronic inflammatory disease, which has been clinically associated with development to oral cancer. A double immunofluorescence labeling study found that 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) accumulated in oral epithelium in OLP and oral squamous cell carcinoma (OSCC) biopsy specimens, whereas little or no immunoreactivity was observed in normal oral mucosa. Colocalization of 8-nitroguanine and inducible nitric oxide synthase (iNOS) was found in oral epithelium of OLP and OSCC. Immunoreactivity of 3-nitrotyrosine, which is formed by protein tyrosine nitration and is considered to be a biochemical marker for inflammation, was also observed in oral epithelial cells and colocalized with 8-nitroguanine. Accumulation of p53 was more strongly observed in oral epithelium in OSCC than OLP, whereas there was no p53 accumulation in normal oral mucosa. Our findings demonstrate that iNOS-dependent DNA damage in OLP may lead to p53 accumulation in not only OLP but also OSCC. We conclude that the formation of potentially mutagenic DNA lesions including 8-nitroguanine and 8-oxodG may contribute to the development of oral cancer from OLP.

Higher expressions of p53 and proliferating cell nuclear antigen (PCNA) in atrophic oral lichen planus and patients with areca quid chewing

OBJECTIVE

The aim of the study was to examine the expressions of p53 and proliferating cell nuclear antigen (PCNA) in oral lichen planus (OLP) in relation to its clinical behavior and the patients' oral habits.

STUDY DESIGN

Immunohistochemical study was carried out to investigate the expressions of p53 and PCNA in 56 OLP specimens. The results were correlated with the clinical behavior of the disease and the patients' oral habits. The expression rates were further compared with those of normal oral mucosa (NOM), epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinoma (SCC).

RESULTS

The staining rate of p53 (28.6%) and PCNA labeling index (LI) (27.6 +/- 8.8%) in OLP were similar to those in EH ( P = .868, .074, respectively), but higher than those of NOM and lower than those of ED and SCC (all P < .05). In OLP, no significant correlations were found between p53 or PCNA expression and the patients' age, gender, lesion duration, location, size, number of site, presence of pain, presence of local irritant, and the habits of alcohol drinking and cigarette smoking (all P > .05). In addition, the mean PCNA LI of p53+ cases was close to that of p53- cases (P = .38). However, the staining rate of p53 in OLP was higher in areca quid (AQ) chewers compared to abstainers (P = .001), and the mean PCNA LI in atrophic cases was higher than that in hypertrophic cases (P = .029). Interestingly, the staining rate of p53 and mean PCNA LI were significantly increased in AQ chewers with atrophic OLP (100%, 36.7% +/- 9.0%, respectively), which were similar to those in ED and SCC (all P > .05).

CONCLUSIONS

Although this study could not confirm the precancerous nature of OLP by the relatively low p53 and PCNA expression, the results do suggest that atrophic form OLP and patients with AQ chewing habit may have a higher disease activity in view of higher expression rates of p53 and PCNA in the lesions.

Apoptosis and cell cycle arrest in oral lichen planus Hypothesis on their possible influence on its malignant transformation

The quantitative importance of cell cycle arrest and apoptosis mechanisms in oral lichen planus (OLP) was analysed in order to assess the cell response to T lymphocyte aggression and establish a hypothesis on the influence of these phenomena in the malignant transformation process. The TUNEL assay and immunohistochemical methods were used to detect caspase-3, bax, and p21 in 32 tissue samples of oral mucosa with OLP and in 20 samples of normal oral mucosa. Positivity for TUNEL, caspase-3 and p21 was significantly more frequent in cases than in controls (p<0.001). Both TUNEL and caspase-3 positivity was significantly greater in the basal versus suprabasal layer (p=0.004 and 0.052, respectively). The basal and suprabasal expression of p21 was significantly higher in cases with a more intense liquefaction degeneration (p<0.01). There was no significant difference in basal expression of bax between cases and controls. The quantitative importance of apoptosis was small in OLP. Epithelial cells attacked in OLP have a very low response to apoptosis and cell cycle arrest mechanisms, which may produce an epithelial substrate that favours malignant transformation.

Analysis of p53 and bcl-2 protein expression in the non-tumorigenic, pretumorigenic, and tumorigenic keratinocytic hyperproliferative lesions

BACKGROUND

The hyperproliferative keratinocytic lesions encompass a wide range of non-tumorigenic, pretumorigenic, and tumorigenic conditions. The aim of this work was to examine the expression patterns of apoptosis-linked molecules (bcl-2 and p53) in these lesions.

METHODS

Immunoperoxidase staining methods were applied to analyze p53 and bcl-2 protein expression in a total of 66 cases, including 12 squamous cell carcinomas (both in situ and invasive SCC), 11 actinic keratoses (AK), 13 psoriasis vulgaris (PV), eight verruca vulgaris (VV), six chronic dermatitis (CD), five seborrheic keratosis (SK), four lichen planus (LP), three epidermodysplasia verruciformis (EDV), two condyloma acuminata (CA), two lichen simplex chronicus (LSC), and 10 specimens from normal skin.

RESULTS

As compared to normal skin (0.70 +/- 0.26), the bcl-2 average weighted scores in the non-tumorigenic (0.76 +/- 0.16), pretumorigenic (1.45 +/- 0.28), and tumorigenic lesions (2.83 +/- 0.50 and 2.92 +/- 0.50 for in situ and invasive SCC, respectively) showed significant up-regulation (p = 0.001). In the non-tumorigenic lesions, the bcl-2 expression values decreased in the following order: SK > EDV > CD > LP > CA > PV > VV (1.40 +/- 0.24 > 1.33 +/- 0.67 > 0.83 +/- 0.40 > 0.67 +/- 0.21 > 0.50 +/- 0.20 > 0.46 +/- 0.22 > 0.13 +/- 0.01, respectively). As compared to normal skin (1.10 +/- 0.23), the p53 average weighted scores in the non-tumorigenic (1.86 +/- 0.18), pretumorigenic (3.64 +/- 0.53), and tumorigenic lesions (5.00 +/- 1.00 and 5.08 +/- 0.86 for in situ and invasive SCC, respectively) showed significant up-regulation (p = 0.021). In the non-tumorigenic lesions, p53 average weighted scores decreased in the following order: SK > PV > CA > LP > CD > VV > EDV (3.20 +/- 0.49 > 2.38 +/- 0.27 > 2.0 +/- 0.0 > 1.83 +/- 0.48 > 1.0 +/- 0.37 > 1.0 +/- 0.33 > 1.0 +/- 0.0, respectively). There was a positive correlation between bcl-2 and p53 protein expression in normal skin (r = 0.966, p = 0.0001), non-tumorigenic (r = 0.775, p = 0.0001), pretumorigenic (r = 0.830, p = 0.001), and tumorigenic lesions (r = 0.757, p = 0.003).

CONCLUSIONS

Bcl-2 and p53 proteins are altered in the keratinocytic hyperproliferative lesions. Determination of whether these alterations reflect underlying gene mutations will require further investigations.

Oral lichen planus: an overview

Lichen planus (LP) is a chronic inflammatory muco-cutaneous disease. Since disorders of NK-cell functional activity could be observed in patients with LP, it is considered to be an autoimmune disease. The pathogenesis of LP is complex and not completely understood. The involvement of mucous membranes is frequently seen, usually asymptomatic, but occasionally complicated by extensive painful erosions, causing a considerable loss of quality of life. Patients with symptomatic oral lichen planus (OLP) often require intensive therapy to reduce the signs and symptoms of this painful and disabling inflammatory disease. OLP is considered to be a precancerous lesion for the development of squamous cell carcinomas. OLP is highly resistant to topical treatment and tends to pursue a chronic course with little tendency to spontaneous resolution. Until now meta-analysis provided little evidence for the superiority of the assessed interventions over placebo for palliation of symptomatic OLP.

Risk of oral squamous cell carcinoma in 402 patients with oral lichen planus: a follow-up study in an Italian population

The most important complication of oral lichen planus (OLP) is the development of oral squamous cell carcinoma (OSCC) but this is a very controversial matter. The aim of the study was to estimate in a Northern Italian cohort of OLP patients the risk for OSCC. Four hundred and two patients with histologically confirmed OLP diagnosed from January 1988 to July 1999, were followed-up to the end of February 2001. The standardized incidence ratio (SIR) of OSCC was calculated for the entire cohort and specific for gender, type of OLP, therapy for OLP and hepatitis C virus (HCV) infection. The relative risk (RR) of OSCC according to HCV infection was also estimated in the cohort. During the follow-up period, two men (1.3%) and seven women (2.9%) developed an OSCC. The SIR was 44.9 (95% CI: 20.5-85.2), being higher among women, but statistically significant in both genders. The RR of OSCC for patients with HCV as compared with those without HCV infection was 3.16 (0.8-12.5). Patients with OLP had a significantly increased risk of OSCC, irrespective of the clinical type of OLP and therapy. HCV infection apparently increased the risk for OSCC although this result could reflect the role of confounders, such as liver cirrhosis.

Psychoneuroimmunology in oral biology and medicine: the model of oral lichen planus

Rheumatoid arthritis involves psychoneuroendocrine-immunopathological comorbidities. In the stoma, patients with rheumatoid arthritis frequently show signs of periondontal disease consequent to elevated levels of crevicular proinflammatory cytokines. It is not clear whether rheumatoid arthritis may manifest in association with immunopathological manifestations of the oral soft mucosa. Oral lichen planus (OLP), first described by E. Wilson in 1859, is a T-cell-mediated inflammatory disease whose lesions characteristically lack B cells, plasma cells, immunoglobulin. or complement. It is increasingly well characterized and recognized as a model for psychoneuroimmunology research in oral biology and medicine. To date, we have shown an association between changes in hypothalamic-pituitary-adrenal (HPA) regulation, systemic markers of cellular immunity and mood states, with clinical stages of OLP (i.e., atrophic vs. erosive vs. bullous lesions). We report significant associations (p < 0.05) between the stage of OLP, HPA deregulation, and altered distribution and functional responses of naïve CD4(+) cells. We emphasize the need to study in greater details the psychoneuroendocrine-immune inter-relationships in OLP, and we propose a novel neuroimmune hypothesis for OLP.