Si src

Pre-miR-203 and pre-miR-control were purchased from ThermoFischer Scientific, (Waltham, USA, #AM17100 pre-miR203a-3p ID assays PM10152 and #AM17111, respectively).
SiRNAs were purchased from ThermoFischer Scientific, Waltham, USA, with the following references: control siRNA, #12935-100; si-SRC(A), #1299001 ID HSS186080; si-SRC(B), #1299001 ID HSS186081, si-RAPGEF1(A), #1299001 ID HSS104431; si-RAPGEF1(B) #1299001 ID HSS104432.
NHK were cultured on a feeder layer of Swiss 3T3 fibroblasts as described previously^{75 (link)}. At 80% confluency they were trypsinized and transfected with pre-miRNA or siRNA at a final concentration of 10 nM, using lipofectamine RNAiMAX reagent (ThermoFischer Scientific, Waltham, USA) in Opti-MEM^® I Reduced Serum Medium (ThermoFischer Scientific, Waltham, USA). After one night of transfection, cells were grown at 37 °C, 5% CO₂, in KGM-Gold w/o Ca²⁺, phenol red free BulletKit (Lonza, Basel, Switzerland), prepared according to the manufacturer’s protocol but without gentamicin/amphotericin B and supplemented with calcium at a final concentration of 50 µM.

The THY1 shRNA sequence was based on our previous study with successful knockdown of THY1 [5 (link)]. Transfection was then conducted in a similar way for THY1 expression, as described in 4.2. For SRC and PTPN22 knockdown, siRNAs (siTHY1, Dharmacon, Lafayette, CO, USA, #L-015337-00-0005; siSRC, ThermoFisher, Waltham, MA, USA, #s13414; siPTPN22, ThermoFisher #s25225; siCTL, Dharmacon #D-001810-10-20) were transfected into NPC cells with Lipofectamine^® 2000 (Invitrogen, Thermo Fisher Scientific, Waltham, MA, USA) as previously described [22 (link)].