V. Masciullo et al., Frequent loss of expression of the cyclin-dependent kinase inhibitor p27 in epithelial ovarian cancer, CANCER RES, 59(15), 1999, pp. 3790-3794
p27(Kip1) is a member of the Cip1/Kip1 family of cyclin-dependent kinase in
hibitors and is a potential tumor suppressor gene. Low levels of p27 are as
sociated with poor prognosis in a variety of tumors, including breast, colo
n, prostate, and lung carcinomas.
In the present study, p27 protein expression was investigated by immunohist
ochemistry and Western blot analysis in a series of 82 epithelial ovarian t
umors [16 classified as low malignant potential (LMP) and 66 classified as
primary ovarian adenocarcinomas], Immunohistochemical analysis revealed fre
quent loss of p27 expression in primary ovarian adenocarcinomas (33%), with
respect to LMP tumors (6%; P = 0.0009). In addition to nuclear staining, c
ytoplasmic localization of p27 was noted in 45 (55%) of 82 cases. p27 level
s inversely correlated with cdk2 kinase activity in a representative subset
of tumors, When the clinical outcome of the patients was evaluated in rela
tionship to p27 status, we observed a significant correlation between prese
nce of p27 staining and a longer time to progression (P = 0.032 by log-rank
test).
These data indicate that loss of p27 is a frequent event in ovarian carcino
mas as compared with LMP tumors, suggesting that these tumor types may have
different pathogenesis, p27 levels mag. also represent a useful prognostic
marker for predicting disease recurrence in primary ovarian carcinomas.