BACKGROUND The clinicopathologic features of thymic epithelial tumors are inadequate as predictors of the progression of these tumors because of their heterogeneous histology and varied biological behavior. We attempted to detect the expression of tyrosine kinase receptors and oncogenic markers to determine the correlation between these markers and the WHO classification of the tumors. METHODS: Forty-three surgically resected thymic epithelial tumors (37 thymomas and 6 thymic carcinomas) were immunohistochemically assessed on tissue arrays for c-KIT, her-2/neu, epidermal growth factor receptor (EGFR), p53. bcl-2 and Ki-67. RESULTS The Ki-67 labeling index was significantly increased in thymic carcinoma (p<0.05). The overexpression of p53 protein was observed exclusively in type B3 thymoma (67%) and thymic carcinoma (83%). Bcl-2 was expressed in type A and AB thymomas as well as in thymic carcinoma. C-KIT was only present in thymic carcinoma (p<0.05), whereas the EGFR expression was significantly high in all types of thymomas, except for thymic carcinomas. Her-2/neu was not identified in any type of thymoma. CONCLUSION: This study suggests that the Ki-67 LI, bcl-2, p53, c-KIT, and EGFR protein expression may be useful markers for the subclassification of thymic epithelial tumors according to WHO schema and WHO classification correlated with the tumor staging. The overexpression of c-KIT in thymic carcinoma reveals that these patients would likely benefit from an anti-c-KIT treatment.
BACKGROUND Tyrosine kinase receptor (TKR) is an important protein for normal-development, growth and tumorigenesis in human tissues. The purpose of this study was to evaluate the effect of TKR in the progression of breast cancer. METHODS The expressions of EphA2, c-met and c-erbB-2 were examined, by using immunohistochemical methods and RT-PCR, in samples of breast tissue that included 111 samples of normal epithelium, 34 samples of ductal carcinoma in situ (DCIS), and 109 samples of invasive ductal carcinomas (IDC).
The results were compared with the prognostic parameters of breast cancer including the tumor grade, growth pattern, lymph node metastasis and the expressions of ER, PR, p53 and Ki-67. RESULTS The protein expressions of the three TKRs were higher in DCIS and IDC than in normal epithelium. The protein expression of EphA2 was correlated with a tumor grade, a labeling index of Ki-67, and the protein expression of c-met. Overexpression of c-erbB-2 was correlated with lymph node metastasis. The mRNA levels of the three TKRs were correlated with each other in normal tissue and IDC.
The level of c-met mRNA was higher in the low grade tumors. CONCLUSIONS The three TKRs may play roles in the tumorigenesis of human breast cancer. The overexpressions of EphA2 and c-erbB-2 may be a poor prognostic parameter in breast cancers.