Cells were grown on RPMI medium (Hyclone, GE Healthcare Life Sciences, Logan, UT, USA) supplemented with 10% (v/v) fetal bovine serum (Hyclone, GE Healthcare Life Sciences, Logan, UT, USA) and gentamicin (Sigma-Aldrich, St. Louis, MO, USA) at 37 ◦C in a humidified atmosphere ...