| Autor: |
Wakasugi, E, Kobayashi, T, Tamaki, Y, Nakano, Y, Ito, Y, Miyashiro, I, Komoike, Y, Miyazaki, M, Takeda, T, Monden, T, Monden, M |
| Zdroj: |
Journal of Clinical Pathology; May1997, Vol. 50 Issue 5, p407-412, 6p, 5 Black and White Photographs, 3 Charts |
| Abstrakt: |
AIM: In order to study the role of retinoblastoma protein (pRB) in breast cancer, the phosphorylation of pRB and the expression of its related proteins-such as cyclin E, cyclin dependent kinase 2 (Cdk2), and p21/Cdk interacting protein 1 (Cip1)-were examined in 30 breast cancers in which pRB overexpression was confirmed immunohistochemically. METHODS: The phosphorylation of pRB for 30 tumours was investigated with western blotting. The expression of pRB, Cdk2/Cdc2, cyclin E, and p21/Cip1 was identified by immunohistochemistry and western blotting. RESULTS: The expression of pRB was confirmed in 52 of 70 tumours (74%) by immunostaining. Western blotting for pRB showed that 25 of 30 representative cancers (83%) were underphosphorylated, while only five tumours showed the hyperphosphorylated form of pRB. However, cyclin E and Cdk2-which promote phosphorylation of pRB-were expressed in all tumours. On the other hand p21/Cip1, a Cdk2 inhibitor, was expressed in 18 of 25 tumours with underphosphorylated pRB, while four of the five tumours with hyperphosphorylated pRB showed no expression of p21/Cip1. Examination of the relation between pRB phosphorylation and clinicopathological variables showed that the underphosphorylated group was characterised by low risk of lymph node metastasis (p < 0.01). CONCLUSIONS: The phosphorylation of pRB appears to be regulated mainly by p21/Cip1 through the suppression of cyclin E and Cdk2 in breast cancer. The underphosphorylated form of pRB may be useful as a prognostic factor. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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