Fig.1.
PTEN silencing decreases sensitivity to trastuzumab and lapatinib. When required cells were either treated with trastuzumab (5 ug/ml), or lapatinib (27 nM) unless otherwise stated. A) Colony formation assay in BT474 cells infected with either NKI library vector PTENkdA, a second independent shRNA vector PTENkdB, or relevant controls. Infected cells were left untreated or treated with trastuzumab, or lapatinib, or both. After 4 weeks cells were photographed and stained with crystal violet. B) Western Blot analysis monitoring PTEN expression in stably infected PTEN knockdown cells. C). Growth curves of stably infected PTEN knockdown BT474 cells treated for 3 weeks with trastuzumab, or lapatinib, or both. Cell numbers were quantified as described in Experimental Procedures. Growth curves were performed in triplicate with the error bars depicting the mean ± s.d. D) Western blot analysis of stably infected BT474 cells with shRNA PTENkdB vector treated overnight with trastuzumab, or lapatinib, or both in 10% serum. Whole cell extracts were analyzed with indicated antibodies.