Cells and tumor models

B16F10 melanoma cell, CT26 mouse colorectal cancer cell, human epidermal growth factor receptor 2 (HER2) positive SKOV3 human ovarian cancer cell (SKOV3-HER2), HEK293T and Phoenix-Eco cell were originally acquired from the American Type Culture Collection. B16-gp33, B16F10-OVA, and YUMM1.7-OVA mouse melanoma cell lines were generated as previously reported^9,49. HER2 transduced MC38 mouse colon cancer cell line (MC38-HER2) and ME275 human melanoma cell line (ME275-HER2) were generated according to the previous publication⁵⁰. All the mouse tumor cells and SKOV3-HER2 cells were cultured in complete Dulbecco’s modified Eagle’s medium (DMEM), a DMEM (Gibco / Thermo Fisher Scientific) medium supplemented with fetal bovine serum (FBS) (10% v/v, Gibco / Thermo Fisher Scientific) and penicillin/streptomycin (1% v/v, Gibco / Thermo Fisher Scientific). ME275-HER2 human melanoma cells were cultured in RPMI-1640 (Gibco / Thermo Fisher Scientific) medium supplemented with FBS (10% v/v, Gibco / Thermo Fisher Scientific), HEPES (pH 7.2~7.5, 1% v/v, Gibco / Thermo Fisher Scientific), penicillin/streptomycin (1% v/v, Gibco / Thermo Fisher Scientific). B16F10, YUMM1.7-OVA, B16F10-OVA, B16-gp33, or MC38-HER2 tumor cells (5 × 10⁵ or 1 × 10⁶ or as indicated) were implanted subcutaneously (s.c.) into the right flanks of Thy1.2⁺ C57BL/6 wild-type (WT) mice to establish the syngeneic tumor models. CT26 mouse colorectal cancer cells (3 × 10⁵) were s.c. inoculated into the right flanks of BALB/c mice.