Rko e6

RH7777 rat hepatoma cells were kindly donated by Dr Chiba K (Mitsubishi Tanabe Pharma). Human CRC cell lines (Caco2, COLO 201, COLO 205, COLO 320DM, HCT116, HT29, LS1034, LS123, LS174T, LS180, RKO, RKO‐E6, SNU‐C1, SW1116, WiDr), PK‐1, PK‐59, PANC‐1, MIA PaCa‐2 pancreatic, BT20, BT474 breast, A549, NCI‐H2170 lung cancers, and P3U1 mouse myeloma cells were purchased from the American Type Culture Collection (ATCC). CCK‐81 and OUMS23 human CRC cells were purchased from JCRN Cell Bank. SW‐C4 is a clone originating from SW1116, and LS‐LM4¹¹ is a highly liver‐metastatic clone from LS174T. The HEK293F human embryonic kidney cell line was purchased from Invitrogen. All cells were cultured in RD medium,¹² which is a blended medium of equivalent volumes of RPMI‐1640 and Dulbecco's modified Eagle medium (Nissui Pharmaceutical Co, Ltd) containing 7% heat‐inactivated fetal bovine serum (FBS, Thermo Fisher Scientific Inc) at 37°C under humid conditions. Aseptic processing during cell culture was ideally controlled by a MediAir air purifier (Pieras Co., Ltd) equipped in the cell‐culture room. Cell growth was measured as previously described.¹³ Briefly, a WST‐8–based cell counting kit (Dojin Chemicals) was used, and 450 nm was measured using a microplate reader.