• Resistance mechanism: BT474R cells have increased AXL expression, which is a novel mechanism of resistance to lapatinib.

  
  

• Sensitivity restoration: AXL kinase inhibition by GSK1363089 (foretinib) can restore lapatinib sensitivity in BT474R cells. ER deprivation or blockade can also restore lapatinib sensitivity by down-regulating AXL.

  
  

• Viability: BT474R cells have a two-fold increased viability after 48 hours of lapatinib treatment.

  
  

• Apoptosis: BT474R cells have a significantly decreased apoptosis after treatment with lapatinib.

  
  

• HER2 and HER3 knockdown: BT474 LLR cells are extremely sensitive to HER2 and HER3 knockdown.

  
  

• Lapatinib dosage: A double dosage of lapatinib (2 μM) suppresses BT474 LLR growth by 60%.

  
  

Lapatinib is a tablet taken orally to slow down the growth of cancer cells. It is usually taken once a day, at least 1 hour before or 1 hour after a meal.