Expression and its relationship of murine double minute 2 and P53 protein in oral leukoplakia and squamous cell carcinoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the expression and its relationship of murine double minute 2 (MDM2), P53 protein in oral leukoplakia and squamous cell carcinoma.</p><p><b>METHODS</b>Immunohistochemical assay was used to detect the expression of MDM2 and P53 proteins in 15 normal oral epithelium tissues, 24 cases of oral leukoplakias and 41 cases of oral squamous cell carcinomas.</p><p><b>RESULTS</b>There were no positive expression of MDM2 and P53 in normal mucosa. With significantly difference compared with the normal group (P < 0.05), the positive rates of MDM2 and P53 were 58.3%, 75.6% and 37.5%, 68.3% in oral leukoplakia and squamous cell carcinoma. MDM2-positive rate had no significant difference (P > 0.05), while P53-positive rate was significant difference (P < 0.05) compared with oral leukoplakia and oral squamous cell carcinoma. Two kinds of indicators for further correlation analysis showed that MDM2 and P53 protein showed a positive correlation relationship both in oral leukoplakia (P = 0.018) and oral squamous cell carcinoma (P = 0.000).</p><p><b>CONCLUSION</b>The expression of MDM2 in oral leukoplakia and oral squamous cell carcinoma suggests that this gene may play a significant role in the process of carcinogenesis of oral squamous cell carcinoma. The correlation of MDM2 and P53 expression indicates that both of them may play a synergistic role in the process of carcinogenesis of oral squamous cell carcinoma.</p>

The expression of human major histocompatibility complex-I in oral leukoplakia / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to examine the expression of human major histocompatibility complex-I at different degrees of dysplasia leukoplakia, and to investigate local immune status and discuss their associations with oral leukoplakia.</p><p><b>METHODS</b>The monoclonal antibody of MHC class I antigen was employed in this study. There were 55 oral leukoplakias, 31 primary oral squamous cell carcinomas and 28 histologically normal oral epithelia were detected for the presence of the MHC class I molecule by using immunohistochemistry method.</p><p><b>RESULTS</b>The MHC class I antigen expression of the severe dysplasia and oral squamous cell carcinoma was significantly lower than that of the normal epithelia (P < 0.05). But their expression did not show statistically difference between the normal epithelia and other groups of oral leukoplakia (P > 0.05).</p><p><b>CONCLUSION</b>The expression levels of the MHC class I antigen is reduced in oral leukoplakia, particularly in severe dysplasia oral leukoplakia, it is relevant to the degree of dysplasia.</p>