Bt 474

LN229, BT-474, MDA-MB-468, HEK-293T, and Chinese hamster ovary (CHO)-K1 cell lines were obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA). LN229/HER2 and CHO/HER2 were established as described previously [23 (link)]. The HEK-293T/HER2-KO cell line (BINDS-23) was generated by transfecting a CRISPR/Cas9 plasmid that targets HER2 [Thermo Fisher Scientific, Inc. (Thermo), Waltham, MA, USA]. CHO-K1 and CHO/HER2 cell lines were cultured in RPMI-1640 medium [Nacalai Tesque, Inc. (Nacalai), Kyoto, Japan]. LN229, BT-474, BINDS-23, and MDA-MB-468 cell lines were cultured in a DMEM medium (Nacalai). Both media were supplemented with 100 units/mL of penicillin, 100 μg/mL streptomycin, 0.25 μg/mL amphotericin B (Nacalai), and 10% fetal bovine serum (FBS, Thermo, Waltham, MA, USA). All cell lines were cultured at 37 °C in a humidified atmosphere with 5% CO₂ and 95% air.

A human breast cancer cell line (BT-474) and a pancreatic cancer cell line (Capan-2) were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA). BT-474 was cultured in Dulbecco’s Modified Eagle Medium (Nacalai Tesque, Inc. (Nacalai), Kyoto, Japan), supplemented with 10% fetal bovine serum (FBS; Thermo Fisher Scientific, Inc. (Thermo), Waltham, MA, USA), 100 units/mL of penicillin, 100 μg/mL streptomycin, and 0.25 μg/mL amphotericin B (Nacalai). Capan-2 was cultured in McCOY’s medium (Cytiva, Tokyo, Japan), supplemented with 10% FBS, 100 μg/mL streptomycin, 100 units/mL of penicillin, and 0.25 μg/mL amphotericin B. The cell lines were maintained in a humidified atmosphere under 5% CO₂ at 37 °C.