Table 3

Activity of CB300638 and CB3717 in human KB cells grown in 1 and 20 nm folate (R,S LV)

Human KB cells that constitutively overexpress the α-FR were cultured in folate-free RPMI 1640 (supplemented with 1 nm or 20 nm R,S-LV as the folate source) and dialysed FCS. Growth inhibition was measured by cell counting after 72 h.

Inhibition of cell growth, IC50, μm
KBKB +1 μm FA
CB3717
 20 nm LV0.0067 ± 0.00160.58 ± 0.20 a(87)
 I nm LV0.0012 ± 0.000730.23 ± 0.045 a(190)
CB300638
 20 nm LV0.0036 ± 0.00150.39 ± 0.18 (110)
 1 nm LV0.0076 ± 0.00310.43 ± 0.18 (57)
  • a Fold increase in IC50 in the presence of 1 μm FA.