Expression of cdk4 and p16 in Oral Lichen Planus.

OBJECTIVES: The purpose of this study was to evaluate the expression of cdk4 and p16, the proteins implicated in hyperproliferation and arrest in oral lichen planus and to compare their expression in erosive and non-erosive oral lichen planus and with normal mucosa and oral squamous cell carcinoma. MATERIAL AND METHODS: Analysis of cdk4 and p16 expression was done in 43 erosive oral lichen planus (EOLP) and 17 non-erosive oral lichen planus (NOLP) cases, 10 normal mucosa and 10 oral squamous cell carcinoma (OSCC) cases with immunohistochemistry. RESULTS: This study demonstrated a significantly increased expression of cytoplasmic cdk4 (80% cases, cells stained - 19.6%), and cytoplasmic p16 (68.3% cases, cells stained - 16.4%) in oral lichen planus (OLP) compared to normal mucosa. cdk4 was much higher in OSCC in both cytoplasm and nuclei compared to normal mucosa. Also, while comparing OLP with positive control, significant difference was noted for cdk4 and p16, with expression being more in OSCC. While comparing EOLP with NOLP; significant differences were seen for cdk4 cytoplasmic staining only, for number of cases with positive staining as well as number of cells stained. CONCLUSIONS: Overexpression of cytoplasmic cdk4 and p16 was registered in oral lichen planus, however considerably lower than in squamous cell carcinoma. Erosive oral lichen planus demonstrated overexpression of cytoplasmic cdk4 and premalignant nature compared to non-erosive lesion. Therefore there is an obvious possibility for cytoplasmic expression of cdk4 and p16 to predict malignant potential of oral lichen planus lesions.

Role of serum interleukin-6 in deciding therapy for multidrug resistant oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is a T cell mediated immune response. T cells locally present in the involved tissues release cytokines like interleukin-6 (IL-6), which contributes to pathogenesis of OLP. Also IL-6 has been associated with multidrug resistance protein (MRP) expression by keratinocytes. Correspondingly, upregulation of MRP was found in OLP. We conducted this study to evaluate the effects of various drugs on serum IL-6 in OLP; and correlation of these effects with the nature of clinical response and resistance pattern seen in OLP lesions with various therapeutic modalities. Thus we evaluated the role of serum IL-6 in deciding therapy for multidrug resistant OLP. MATERIAL AND METHODS: Serum IL-6 was evaluated in 42 erosive OLP (EOLP) patients and 10 normal mucosa and 10 oral squamous cell carcinoma cases using ELISA technique. OLP patients were randomly divided into 3 groups of 14 patients each and were subjected to Pimecrolimus local application, oral Mycophenolate Mofetil (MMF) and Methotrexate (MTX) alongwith Pimecrolimus local application. IL-6 levels were evaluated before and after treatment. RESULTS: Serum IL-6 levels were raised above 3pg/ml in 26.19% erosive OLP (EOLP) cases (mean- 3.72±8.14). EOLP (5%) cases with IL-6 levels above 5pg/ml were resistant in MTX group. However significant decrease in serum IL-6 corresponding with the clinical resolution was seen in MMF group. CONCLUSIONS: Significantly raised IL-6 levels in EOLP reflect the chronic inflammatory nature of the disease. As serum IL-6 levels significantly decreased in MMF group, correspondingly no resistance to treatment was noted. However with MTX there was no significant decrease in IL-6 and resistance to treatment was noted in some, especially plaque type lesions. Thus IL-6 can be a possible biomarker in deciding the best possible therapy for treatment resistant OLP. KEY WORDS: Lichen planus, biological markers, cytokines, enzyme-linked immunosorbent assay, immunosuppressive agents.

Profiling of Pro-Inflammatory Cytokines in Radiation Induced Oral Mucositis (RIOM) among Indian patients

Radiation-induced oral mucositis (RIOM) is aimed at evaluating the expression of NF-κß, IL-1α, IL-6, IL-8 and TNF-α in patients with RIOM so as to validate their role in the pathobiology of the disease. Blood samples were collected and serum of 45 patients isolated with clinical signs and symptoms of mucositis and 10 healthy controls were also included in the study. The expression level of NF-κß, IL-1α, IL-6, IL-8, TNF-α was investigated using ELISA. Mann Whitney U test was applied to find the significance of the expression of these markers in RIOM patients as compared to normal healthy controls and significant expression (P< 0.05) for NF-κß, IL-6, TNF-α and non-significant expression (P > 0.05) IL-1α and IL-8 was found. No significant change in the expression level of the cytokines was observed for patients undergoing chemotherapy and radiation therapy as well as those receiving only the radiation therapy as a part of their treatment. We have also found less expression in grade 1 of mucositis as compared to grade 4. Pro- inflammatory cytokines indeed play a vital role in the pathogenesis as well as progression of RIOM (AU)