Table 1 Effect of hormonal status on cdkI association with cdk4 and cdk2 at early stages in mammary preneoplasia

Virgin EL11 TM2L

 BrdUrd L.I. 1 NC {uparrow}1.6
 Tumor incidence None None 61%
 p27/cdk2 1 {uparrow}2.4 {uparrow}4.2
 p27/cdk4 1 {downarrow}1.2 {downarrow}1.4
 p16/cdk4 1 {downarrow}1.6 {downarrow}4.2
 p21/cdk2 1 {downarrow}3.7 {downarrow}4.2
 BrdUrd L.I. {downarrow}14.8 {downarrow}2.5 {downarrow}1.5
 Tumor incidence None None 53%
 p27/cdk2 {uparrow}3.3 {uparrow}2.2 NC
 p27/cdk4 {uparrow}1.3 {uparrow}4.7 {uparrow}1.9
 p16/cdk4 NC {uparrow}2.5 {uparrow}1.5
 p21/cdk2 {uparrow}1.7 {uparrow}2.8 {uparrow}1.5
 BrdUrd L.I. {uparrow}2.2 {uparrow}1.6 NC
 Tumor incidence None None 74%
 p27/cdk2 {downarrow}2.3 {uparrow}3.9 {downarrow}12.4
 p27/cdk4 {downarrow}9.4 {uparrow}2.7 {downarrow}5.6
 p16/cdk4 {downarrow}5.0 {downarrow}3.0 {downarrow}4.2
 p21/cdk2 {downarrow}12.6 {downarrow}1.7 {downarrow}4.9

a Number of fold difference from normal virgin gland. L.I., labeling index; NC, no change.

b Number of fold difference compared with the internal control of each group. OVX, ovariectomized; +Pit, with pituitary isograft.