F. Basolo et al., Cyclin D1 overexpression in thyroid carcinomas: Relation with clinico-pathological parameters, retinoblastoma gene product, and Ki67 labeling index, THYROID, 10(9), 2000, pp. 741-746
Cyclin D1 is a G1 cyclin participating in the control of cell cycle progres
sion through interaction with the retinoblastoma gene product (pRB). The ov
erexpression of positive regulators (such as cyclin D1) has been reported i
n a variety of neoplasms, but their role in thyroid tumorigenesis is yet to
be established. In our series of 54 thyroid carcinomas, cyclin D1 overexpr
ession (detected by both immunohistochemistry and by Northern blotting) was
correlated with prognostic variables, proliferative activity and pRB. Cycl
in D1 overexpression was observed in 35% of thyroid carcinomas with a signi
ficantly higher expression of this cyclin in neoplastic tissues than in mat
ched normal parenchyma. In well-differentiated carcinomas, the cyclin D1 mR
NA overexpression was inversely correlated with nodal status (p = 0.03), wh
ile the protein product was higher in tumors from patients less than 40 tha
n patients over 40 years of age. Inversely, there was no significant correl
ation with gender and tumor status, pRB and with proliferative activity.