Objectives: The c-kit gene encodes a transmembrane receptor-type tyrosine kinase, which is known to have a significant role in the normal migration and development of germ cells and melanocytes. In the previous studies of c-kit gene, c-kit expressions showed only in adenoid cystic carcinomas, lymphoepithelioma-like carcinomas and myoepithelial carcinomas, but not in others and mutation was not found in any types of salivary carcinoma. We investigate the c-kit expression which may be useful to differentiating adenoid cystic carcinomas from others, and mutation of the gene which may not be exist nor the mechanism of c-kit activation in salivary carcinomas.
Material and Methods: The archival tissue samples from 42 salivary carcinomas of major and minor salivary glands were studied for c-kit expression by immunohistochemistry and gene mutation by polymerase chain reaction amplification and single strand conformational polymorphism.
Results: The c-kit expressions were noted in 22/24 adenoid cystic carcinomas, 7/9 mucoepidermoid carcinomas, 2/3 acinic cell carcinomas, 3/4 malignant mixed tumors, and one undifferentiated carcinoma. The mutation of c-kit gene was found in 3/24 adenoid cystic carcinomas, 3/8 mucoepidermoid carcinomas, one acinic cell carcinoma, and 2/4 malignant mixed tumors.
Conclusion: c-kit protein overexpression is seen in a variety of salivary gland carcinomas, and the mutation of the gene may be the mechanism of c-kit activation in these neoplasms.
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