Figure 7.

Survival of patients with breast tumors and breast cancer lines depending on Cdk5 expression profile. (A) MFS curves for breast tumor patients with high (NCdk5 > 3.8) and low (NCdk5 ≤ 3.8) tumor expression levels of Cdk5 mRNA. The mean patient follow-up was 9.5 years (range 5 months to 33 years) and 169 patients in the cohort developed metastases. (B) Survival of HCC1954 and BT549 breast tumor cell lines. Cells were transfected either with a siRNA control or a siRNA directed against Cdk5 expression. 72 h later they were plated and left to attach for 4 h before treatment with or without the PARP inhibitor ABT888 (10 μM). 24 h after treatment cell culture medium was changed and colonies grown for 8 days and counted. Data are the mean numbers of colonies counted ± SD from 2 independent experiments each in triplicate (*P < 0.05; **P < 0.01; ***P < 0.001, unpaired t-test). (C) Clonogenic cell survival of HCC1954 (left panel) and BT549 (right panel) breast tumor cells depending on Cdk5 expression after increasing doses of gamma-irradiation in the presence or not of a PARP inhibitor. Cells were transfected with either a control or Cdk5 siRNA as in panel (B) and then the PARP inhibitor ABT888 (10 μM) added 1 h prior to radiation. 24 h after treatment cell culture medium was changed and colonies grown for 8 days and counted. Data are the mean survivals of 2 independent experiments each in triplicate (*P < 0.05; **P < 0.01, unpaired t-test). (D) Representative western blot of breast cancer cell lines after transfection with siRNA control or Cdk5.