Protein expression of cell cycle regulator, p27Kip1, correlates with histopathological grade of non-Hodgkin's lymphoma.
The protein p27Kip1 is one of the cyclin-dependent kinase inhibitors that are known to play important roles in the regulation of cell-cycle progression. Low levels of p27 expression in malignant cells are associated with poor prognosis in patients with breast, lung, colorectal and gastric cancers. To determine the relation of cyclin-dependent kinase inhibitors to histopathological grades of B-cell non-Hodgkin's lymphomas, the expression of p27, cyclin D1 and cyclin E in lymph node tissues was investigated in 56 patients with B-cell non-Hodgkin's lymphomas by western blotting and immunohistochemical techniques. High levels of p27 expression were observed in most lymph node tissue samples (93%) obtained from patients with low grade B-cell non-Hodgkin's lymphomas, while expression was low in lymph node tissue taken from all patients with intermediate and high grade B-cell non-Hodgkin's lymphomas. The difference in p27 expression in lymphoma tissues was significant among the different histopathological grades of B-cell non-Hodgkin's lymphomas (P<0.01). The analysis of the survival time of patients showed that the reduction of p27 expression correlated with poor prognosis. Cyclin D1, showed a high level of expression in mantle cell lymphomas and high grade B-cell non-Hodgkin's lymphomas. Cyclin E showed limited expression in 18 of 31 lymphoma tissues. Both cyclin D1 and E protein expression were not significantly different among the grades of B-cell non-Hodgkin's lymphomas. These results demonstrate that the level of p27 expression in lymphoma tissue is an important parameter in the classification of B-cell non-Hodgkin's lymphomas and in the prediction of prognosis.
Kudoh
S
S
Department of Cancer Cytogenetics, Research Institute for Radiation Biology and Medicine, Hiroshima University.
Kumaravel
T S
TS
Kuramavel
B
B
Eguchi
M
M
Asaoku
H
H
Dohy
H
H
Fujiwara
M
M
Sasaki
N
N
Tanaka
K
K
Kamada
N
N
D015153:Blotting, Western; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D019938:Cyclin D1 / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27; D005455:Fluorescent Antibody Technique; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D011379:Prognosis; D016019:Survival Analysis; D025521:Tumor Suppressor Proteins
D018797:Cell Cycle Proteins; D019927:Cyclin E; D008869:Microtubule-Associated Proteins; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27