5 n ethyl n isopropyl amiloride eipa

Abx was labeled with FITC using fluorescein-EX protein labeling kit (Thermo Fisher). A 0.5 mL solution of 2 mg/mL abraxane was mixed with 50 µl of 1 M bicarbonate and incubated with the reactive dye for 1 h at room temperature. The labeled Abx was purified from free dye using a spin column (MW > 20 kDa). Cells (1 × 10⁵ cells/well of a four-well chamber) were incubated with 1% bovine serum albumin at 24°C for 30 min and then with 5 μg/mL of FITC-labeled Abx at 37 °C for 1 h. Cells were fixed with 4% paraformaldehyde followed by nuclear staining with 4', 6-diamidino-2-phenylindole (DAPI) after washing and observed under a confocal microscope (Nanoscope, Daejeon, Korea), or cells were analyzed using Attune NxT flow cytometer (Thermo Fisher). For the internalization inhibition, cells were incubated with 50 μM of 5-(n-ethyl-n-isopropyl) amiloride (EIPA, Thermo Fisher), 50 μM of chlorpromazine (CPZ, Sigma-Aldrich), and 100 μM of anti-IL4Rα blocking antibody or anti-IgG antibody (R&D Systems, Minneapolis, MN) for 30 min prior to incubation with FITC-labeled Abx.

A table containing all employed antibodies as well as their cellular target, supplier and catalogue number is provided as Supplementary Table S2.
Cariporide was a gift from Sanofi-Aventis and 5-(N-ethyl-N-isopropyl) amiloride (EIPA) (#E3111) was from Thermo-Fisher. β-actin antibody (#A5441), tamoxifen (#T5648), cisplatin (#P4394), 5-fluorouracil (5-FU) (#F6627), 5-(N,N-Dimethyl) amiloride (DMA) (#A4562), 5-(N,N-Hexamethylene) amiloride (HMA) (#A9561) and amiloride (#A7410) were from Sigma-Aldrich, and doxorubicin (#120629) and eniporide (#HY-106150B) from Abcam and MedChemExpress, respectively. Akt (Akti, #124018) and MEK (U0126, #662005) inhibitors were from Calbiochem. Horseradish Peroxidase (HRP)-conjugated anti-mouse- (#P0447) and anti-rabbit (#P0448) antibodies were from Dako, and Alexa Fluor anti-mouse (#A11019) and anti-rabbit (#A11070) fluorophore-conjugated secondary antibodies were from Invitrogen.