Metallothionein, a marker of antiapoptosis, is associated with clinical forms of oral lichen planus

Metallothioneins and Megalin Expression Profiling in Premalignant and Malignant Oral Squamous Epithelial Lesions

This study aimed to assess the relationship and possible interactions between metallothioneins (MTs) and megalin (LRP-2) in different grades of oral squamous cell carcinoma (OSCC) and premalignant lesions of the oral mucosa (oral leukoplakia and oral lichen planus). The study included archived samples of 114 patients and control subjects. Protein expression was examined by immunohistochemistry and immunofluorescence, and staining quantification was performed by ImageJ software. Protein interaction in cancer tissue was tested and visualized by proximity ligation assay. Mann-Whitney and Kruskal-Wallis tests were used to determine the significance of differences between each group, whereas Pearson correlation coefficient was performed to test correlation. Expression of both proteins differed significantly between each group showing the same pattern of gradual increasing from oral lichen planus to poorly differentiated OSCC. Moreover, MTs and megalin were found to co-express and interact in cancer tissue, and their expression positively correlated within the overall study group. Findings of prominent nuclear and chromosomal megalin expression suggest that it undergoes regulated intramembrane proteolysis upon MTs binding, indicating its ability to directly affect gene expression and cellular division in cancer tissue. The data obtained point to the onco-driving potential of MTs-megalin interaction.

Differential metallothionein expression in oral lichen planus and amalgam-associated oral lichenoid lesions

Background

Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL.

Material and Methods

We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry.

Results and Conclusions

White OLP has higher concentrations of metallothionein than red OLP in basal and parabasal layers. Moreover, metallothionein was more frequently observed in the cytoplasm and nuclei of basal cells in OLP patients compared to the same regions of OLL cases. Metallothionein levels are related to OLP severity and may contribute to a differential diagnosis between OLP and OLL.

Key words:Oral lichen planus, oral lichenoid lesions, autoimmune disorders, metallothionein, immunohistochemistry.

Programmed cell removal biomarkers calreticulin and CD47 implicated in oral lichen planus

OBJECTIVES

To investigate the expression of the programmed cell removal markers, calreticulin (CRT) and CD47, known to be involved in various autoimmune diseases, in patients with oral lichen planus (OLP), and to investigate the association with clinical behavior.

MATERIALS AND METHODS

Biopsies of 78 patients with OLP were included. The clinical data were collected from patients' charts. The expression of CRT and CD47 was immunomorphometrically analyzed in the epithelial (CRTep, CD47ep) and inflammatory cells (CRTinf, CD47inf), and the results were correlated with the clinical presentation.

RESULTS

The epithelial and inflammatory cells expressed CRT (2.83 ± 6.62 and 5.13 ± 3.72) and CD47 (7.92 ± 4.6 and 10.7 ± 7.16). The expressions of CD47ep and CD47inf were associated (R = 0.64, P < 0.0005) with one another. The expressions of CRTinf and CD47ep were higher in atrophic erosive forms (A/ELP) than in the keratotic form of patients with OLP (6.46 ± 0.76 and 9.38 ± 0.87 vs 4.2 ± 0.61 and 6.84 ± 0.91, respectively, P = 0.002 and P = 0.021). The expression of CRTep was associated with more localized lesions (P < 0.009) and more abundant in males (P = 0.049), and the expression of CRTinf was associated with the presence of skin lesions and symptoms (P < 0.034 and P = 0.047, respectively). Only in A/ELP patients, the expression of CRTep was associated with high expression of CD47ep (R = 0.6, P = 0.004), where both CD47ep and CD47inf were associated with lower age of the patients (R = -0.48, P = 0.03 and R = -0.54, P = 0.01).

CONCLUSIONS

The pattern of expression of CRT and CD47 in OLP suggests a general programmed cell removal response in OLP. Symptomatic patients may benefit from CRT/CD47 targeted therapy in the future.