Overexpression of cyclin E in acute myelogenous leukemia.
Cyclin E is one of the G1 cyclins that play an important role in cell proliferation. Overexpression of cyclin E protein has been reported in several solid tumors, but little is known about the involvement of cyclin E in leukemia. In this study, we analyzed the expression of cyclin E gene product in 85 patients with acute myelogenous leukemia (AML) by Western blot analysis. In 23 of 85 AML samples (27%), cyclin E expression was enhanced in blasts. Among the French-American-British classification of AML, the ratio of the samples with enhanced cyclin E expression was high in M5 and low in M2 and M3. No rearrangements were observed by Southern blot analysis in these AML blasts with enhanced cyclin E expression. Flow cytometric analysis showed no correlation between overexpression of cyclin E and cell cycle distribution. Immunoblot analysis of cyclin D1 showed no correlation between overexpression of cyclin E and that of cyclin D1. Interestingly, p27 expression detected by Western blotting was apparently enhanced in 18 of 23 AML cells with enhanced cyclin E expression but none of 14 AML cells without enhanced cyclin E exhibited enhanced p27 expression. The rates of complete remission and of disease-free survival of the patients with M4 or M5 leukemia blasts with overexpressed cyclin E seemed to be low. Therefore, we suggest the necessity of a larger-scale study to elucidate the contribution of cyclin E overexpression to the phenotype and the prognosis of certain AML.
Iida
H
H
First Department of Internal Medicine, Nagoya University School of Medicine, Nagoya, Japan.
Towatari
M
M
Tanimoto
M
M
Morishita
Y
Y
Kodera
Y
Y
Saito
H
H
D000328:Adult; D000368:Aged; D015139:Blotting, Southern; D015153:Blotting, Western; D019927:Cyclin E / Q000096:biosynthesis*; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
D019927:Cyclin E