Skip to main content
. 2006 Dec 7;117(1):218–228. doi: 10.1172/JCI28803

Figure 1. Efficient RB knockdown in breast cancer cells causes deregulation of RB/E2F target genes and increased proliferation kinetics.

Figure 1

(A) MCF7 cells transfected with MSCV donor or MSCV siRb plasmids were selected with puromycin to isolate stable clones. Clones were screened by RB immunofluorescence as shown for MCF7 donor 1 and siRb28. Images were captured at equal exposures. Original magnification, ×20. (B) Lysates from MCF7 donor 1 and siRb28 clones were immunoblotted for expression levels of RB, PCNA, MCM7, cyclin E, cyclin A, cyclin D1, and p16INK4a. Cdk4 served as a loading control. (C) Cells represented in A were BrdU labeled for 10 hours, and BrdU immunofluorescence was performed and scored. (D) Cells represented in A were seeded at 3 × 105, cell growth assays were carried out for 9 days, and cells were counted every 3 days. (E) Lysates represented in B along with lysates from polyclonal populations of T47D and Zr-75-1 cells infected with retrovirus encoding donor or siRb88 plasmids were immunoblotted for expression levels of RB and cyclin D1. Lamin B served as a loading control. (F) Retrovirally infected T47D and Zr-75-1 cells represented in E were seeded at 3 × 105, and growth assays were carried out as described for D.