- The Expression of c-met Oncogene in Thyroid Tumor.
-
Won Young Lee, Young Don lee, Young Jig Lee, Geun Sin Ryu
-
J Korean Endocr Soc. 2001;16(1):65-74. Published online February 1, 2001
-
-
-
 Abstract
 PDF
- BACKGROUND
The proto-oncogene c-met encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF), which is a pleiotropic cytokine that controls growth, survival, motility, invasive migration, and differentiation of epithelial cells. Like several other epithelial neoplasms, thyroid carcinomas have been found to overexpress the c-met oncogene. We presently examine the expression of c-met protein in thyroid tumors and the correlation of c-met protein expression with prognostic factors in thyroid cancers. METHOD: We have examined the expression of the c-met oncogene in 62 paraffin-embedded thyroid cancer specimens (54 papillary carcinomas, 5 follicular carcinomas, 2 medullary carcinomas, and 1 anaplastic carcinoma), 20 benign tumors and 20 normal tissues using immunohistochemistry. We measured both the proportion and the intensity of stained cells and then calculated the staining index by multiplying the proportion and intensity scores. The staining index were categorized to be negative/low (staining index < or = 5) or high(staining index >5). The most important prognostic factors were age (over 45), tumor size (over 1.5 cm), lymph node metastasis, capsular invasion, vascular invasion and peripheral metastasis. RESULT: 1) The rate of expression of the c-met oncogene were 100%, 100% and 60% in thyroid cancer, benign tumors and normal thyroid tissue respectively. The expression of the c-met oncogene was restricted to the membrane. 2) The staining index of normal tissue, benign tumors and thyroid carcinomas was 1.8, 4.3 and 5.8 respectively. In malignancies, the staining index of papillary carcinoma was 5.7, follicular carcinoma 5.4, medullary carcinoma 7.5, and anaplastic cancer 9. 3) A high expression of c-met was not correlated with prognostic factors in papillary, follicular carcinomas or medullay carcinomas. CONCLUSION: The c-met oncogene might not play a role in the pathogenesis of thyroid neoplasia. There was no correlation between the high expression rate of the c-met oncogene and prognostic factors in papillary and follicular carcinomas.
|
KES
