Molecular Markers in Oral Lichen Planus - Insight into Pathogenesis

PURPOSE

Oral lichen planus (OLP) is a chronic inflammatory disease, characterized by immune-mediated basal keratinocyte apoptosis. In recent years the importance of programmed cell death for the tissue destruction in OLP has been disputed, while at the same time an increased proliferative index has been reported in the epithelium of these lesions. OLP is considered as a precancerous condition. This study investigated the expression of pro-apoptotic, anti-apoptotic and proliferative markers in OLP lesions in an attempt to understand more about the pathogenesis and malignant potential of the disease.

METHODS

Twenty patients with histologically confirmed OLP were compared to ten healthy controls through immunohistochemical analysis of the levels of p53, p63, bcl-2, Ki-67 and COX-2.

RESULTS

The results demonstrated significantly decreased expression of p63 in OLP lesions compared to normal oral mucosa. The levels of p53, bcl-2, Ki-67, and COX-2 were not significantly different from those in the control group. A significant association was found between p63 and Ki-67 (p = 0.001), as well as between p63 and p53 (p = 0.016). Expression of the inflammatory COX-2 and the apoptotic p53 appeared to be independent of each other (p = 0.44). The intensity of expression of any of the five analyzed markers was not related to the severity of the clinical manifestation.

CONCLUSIONS

The obtained results suggest that apoptosis may not be the dominant mechanism in the disease's pathogenesis. Decreased expression of p63 on the other hand appears to play an important role. Among the possible effects of this protein deficiency are activation of programmed cell death, cell cycle arrest, cellular senescence, or anoikis; suppression of cell proliferation or changes in cell differentiation. The observed reduction in p63, Ki67 and bcl-2 levels predisposes to epithelial thinning, erosions and/or ulcers. For the presented OLP cohort, there was no molecular evidence of increased malignant potential of the lesions.

Elevation of Serum SSCCAII in Cutaneous and Oral Lichen Planus: Missing Link for Hidden Carcinogenic Potential?

Context:

Lichen planus (LP) is an immune mediated inflammatory condition. SCCAII is a useful biomarker reflecting Th17 type inflammation. It is also a tumour marker, especially for Squamous cell carcinoma (SCC) Mechanism of carcinogenesis in LP is still unknown. Chronic inflammation may facilitate the development of cellular clones in the epidermis.

Aims:

Estimation of serum level of SCCA II in patients with cutaneous and oral LP (OLP) to detect its role in LP pathogenesis, and to reveal the missing link in understanding mechanism of carcinogenesis in LP.

Methods and Material:

A case control study, where 100 subjects were included; 80 LP patients (40 cutaneous & 40 oral) and 20 apparently healthy controls. We obtained an informed written consent from each subject prior the participation. Cutaneous and oral LP were diagnosed clinically, SCCA II level was measured by ELISA technique.

Statistical analysis used:

Statistical analysis was done using SPSS vs.25. (IBM, Armonk, New York, United states). Numerical data was summarized as means and standard deviations or medians and ranges.

Results:

Median SSCCAII level was significantly higher in LP cases compared to controls (P < 0.001) and was significantly higher in patients with OLP compared to patients with cutaneous LP (P ≤ 0.001). Post hoc analysis revealed that median SSCCAII was significantly higher in patients with ulcerative type compared to both reticular type and others. It was also significantly higher in patients with actinic type compared to both hypertrophic type and classic type. Median SSCCAII was significantly higher in patients with ulcerative OLP compared to actinic LP (P < 0.001).

Conclusions:

Our study revealed that serum SCCAII level was higher in patients with cutaneous and OLP. This might be linked to the pathogenesis of LP, especially actinic and erosive OLP. SCCAII level could facilitate the screening and early detection of patients at risk, a potential alarm to launch accurate assessment and continue follow up of cutaneous as well as O LP patients.

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.

Analysis of Ki-67 Expression in Oral Premalignant Lesions and Normal Oral Mucosa: An Immunohistochemical Study

Aim:

This study aimed to evaluate the Ki-67 expression in oral premalignant lesions and normal oral mucosa.

Materials and Methods:

The cases were selected on the basis of the details obtained from the patients. A total of 45 specimens were divided into three groups: Group 1 (normal mucosa), Group 2 (clinically and histologically diagnosed as oral lichen planus), and Group 3 (clinically and histologically diagnosed as leukoplakia). Specimens were prepared and the slides for Ki-67 were observed under light microscope with a magnification of ×400. The tissue samples were thoroughly examined, and the pattern of expression was analyzed semiquantitatively by counting the number of positive cells.

Results:

The mean positive cell count of normal mucosa was 23.20 ± 2.89, of oral lichen planus was 42.82 ± 2.65, and of leukoplakia was 82.14 ± 3.10. There was a statistically significant difference of expression observed between the groups (P < 0.001). On multiple comparisons using Tukey post hoc test, a statistical difference was found between all the three groups.

Conclusion:

Ki-67 is an easily applicable marker of cell proliferation whose expression correlates well with the disease progression.

Role of cell proliferation and vascularity in malignant transformation of potentially malignant disorders

BACKGROUND

Significant increase in cell proliferation and vascularity occurs during the transition from normal oral mucosa through differing degrees of dysplasia to oral squamous cell carcinoma (OSCC).

AIMS

To evaluate the cell proliferation and vascularity in potentially malignant disorders and OSCC.

SETTINGS AND DESIGN

Proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF) and CD34 were quantified immunohistochemically (IHC) using anti-PCNA, anti-VEGF and anti-CD34 antibody.

MATERIALS AND METHODS

A total of 60 archival specimens included 10 oral lichen planus, 10 oral leukoplakia, 10 oral submucous fibrosis and 30 OSCC (well differentiated, moderately differentiated and poorly differentiated), and also, 10 normal oral mucosa as control group were taken. PCNA, VEGF and CD34 expression was assessed in relation to the localization and area of IHC-stained cells.

STATISTICAL ANALYSIS

One-way analysis of variance test and post hoc least significant difference test were assessed for statistical significance.

RESULTS

Cell proliferation and vascularity appeared to increase gradually with disease progression.

CONCLUSION

Upregulation of cell proliferation and vascularity indicates their possible role in malignant transformation of potentially malignant disorders.

Oral lichen planus and malignant transformation: The role of p16, Ki-67, Bub-3 and SOX4 in assessing precancerous potential

The association of oral lichen planus (OLP) lesions with malignant transformation risk has remained a controversial topic and is of clinical importance. Therefore, the present study evaluated the expression levels of p16, Ki-67, budding uninhibited by benzimidazoles 3 (Bub-3) and sex-determining region Y-related high mobility group box 4 (SOX4), and their roles as precancerous biomarkers in OLP. A retrospective study was performed, in which tissue blocks of OLP, oral dysplasia (OD), cutaneous lichen planus (CLP) and oral fibrous hyperplasia (OFH) were used (n=120). A positivity index (PI) for p16, BUB3, Ki-67 and SOX4 expression was calculated in each group. The PI for p16 was 20.65% for OLP, 7.85% for OD, 86.59% for CLP and 11.8% for OFH, and the difference between these groups was statistically significant (P<0.001). PIs of Ki-67 were indicated as 11.6% for OLP, 14.4% for OD, 8.24% for CLP and 5.5% for OFH, and a statistically significant difference was observed between the groups (P<0.001). Notably, the expression levels of BUB3 were not statistically different among groups. The highest expression levels of SOX4 were identified in CLP (P<0.001 vs. OLP/CLP; P=0,001 vs. CLP/OD). The determined expression levels of p16 and Ki-67 suggest that specific OLP lesions may have an intermediate malignant potential and should be carefully followed up. The intense SOX4 staining in CLP indicated a different proliferation pattern of epithelium compared with oral mucosa cells. These findings suggest that SOX4 expression may also be associated with the different clinical courses of OLP and CLP.

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.

Oral lichenoid lesions: distinguishing the benign from the deadly

Oral lichen planus is a chronic inflammatory disease of unknown etiology or pathogenesis with varied disease severity that waxes and wanes over a long period of time. Although a common oral mucosal disease, accurate diagnosis is often challenging due to the overlapping clinical and histopathological features of oral lichen planus and other mucosal diseases. Other immune-mediated mucocutaneous diseases can exhibit lichenoid features including mucous membrane pemphigoid, chronic graft-versus-host disease, and discoid lupus erythematosus. Reactive changes to dental materials or to systemic medications can mimic oral lichen planus both clinically and histologically. In these situations the clinical presentation can be useful, as oral lichen planus presents as a multifocal process and is usually symmetrical and bilateral. Dysplasia of the oral cavity can exhibit a lichenoid histology, which may mask the potentially premalignant features. Proliferative verrucous leukoplakia, an unusual clinical disease, can often mimic oral lichen planus clinically, requiring careful correlation of the clinical and pathologic features.

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.

In situ carcinoma developed over oral lichen planus: a case report with analysis of BUB3, p16, p53, Ki67 and SOX4 expression

Oral lichen planus (OLP) represents a common mucocutaneous disease. Various authors have suggested that OLP has malignant potential; however, the mechanisms involved in malignant transformation have not yet been elucidated. A 79-year-old man presented a white lesion for five months in the buccal mucosa diagnosed as OLP. After two months using 0.05% clobetasol ointment for treatment, the lesion became ulcerated. A new biopsy of the same lesion was performed, and histological analysis showed an in situ oral carcinoma (ISOC). An immunohistochemistry panel was performed, and p16 expression was negative in OLP, however, it showed weak cytoplasmic staining in ISOC. There was strong nuclear BUB3 staining in both OLP and ISOC areas. p53 showed less intense nuclear staining in both regions. Ki67 was negative in OLP area, but showed nuclear staining in the ISOC. SOX4 was negative in both studied areas. BUB3 expression, first reported in this case, and the p16 expression may suggest some influence of these genes on pathogenesis or malignant potential of OLP.