Ith 10 fetal bovine serum (FBS), non-essential amino acids, 1 mM sodium pyruvate, 1 nM T3, 0.5 g/mL hydrocortisone, 8 ng/mL epidermal growth factor, 25 mM HEPES, and 0.1 mg/mL Primocin. MDA-T41 cells were obtained from G. Clayman (University of Texas MD Anderson Cancer Center, Houston, TX). K1 cells were provided by D. Wynford-Thomas (Cardiff University, Cardiff, UK). T238 were obtained from L. R