Cyclin D1 is a cell cycle regulator of G(1) progression that has been
suggested to play a relevant role in the pathogenesis of several human
cancer types. In the current study, the expression of cyclin D1 has b
een investigated in a series of 33 patients, with benign (10 patients)
, borderline (five patients) and malignant (18 patients) ovarian disea
se. Cyclin D1 protein and mRNA content were analysed by Western blotti
ng and reverse transcriptase polymerase chain reaction respectively. T
he levels of cyclin D1 protein were undetectable in patients with beni
gn disease, detectable in the majority of patients with borderline dis
ease and elevated in those with ovarian carcinomas, being significantl
y related to the degree of malignancy (carcinoma vs benign, P=0.0001;
benign vs borderline, P=0.0238). A significant relationship between cy
clin D1 expression and tumour proliferative activity was also found (P
=0.000001). Moreover, eight benign lesions, two borderline tumours and
11 carcinomas proved to be suitable for the analysis of cyclin D1 tra
nscript, and emerging data demonstrated significant agreement between
protein abundance and mRNA expression. Results from the current study
suggest that cyclin D1 expression is associated with the degree of tra
nsformation and most probably plays a role in the early development of
ovarian malignancy.