Hela cells

Eight human cancer xenografts were used (CRC cell lines DLD-1, HT-29, HCT116, KM20C and SW480; small cell lung cancer cells Lu-134; breast cancer cells MC-2 and MX-1). Lu-134, MC-2 and MX-1 were maintained by serial transplantation in the dorsum of nude mice. Other xenografts were established by implantation of cultured cells before each study. Lu-134 and MC-2 were obtained from the Central Institute for Experimental Animals (Tokyo, Japan). NUGC-3, HT-29 and MX-1 cells were provided by the Japanese Foundation for Cancer Research (Tokyo, Japan). DLD-1 and HCT116 cells were obtained from Dainippon Pharmaceutical (Tokyo, Japan). KM20C cells were kindly provided by the National Cancer Center (Tokyo, Japan). SW480 cells were purchased from American Type Culture Collection (Manassas, VA, USA). HeLa cells were obtained from the Health Science Research Resources Bank (Tokyo, Japan). These cultured cells were maintained at 37°C with 5% CO₂, in the culture medium recommended by each provider.

We used NIH 3T3 cells (JCRB0615; Health Science Research Resources Bank, Japan Health Science Foundation, Japan) and HeLa cells (JCRB9004; Health Science Research Resources Bank, Japan Health Science Foundation, Japan) as adhesive cells. The cells were cultured in Dulbecco’s minimal essential medium (Invitrogen Corp., USA) supplemented with 10% fetal bovine serum, 100 U mL⁻¹ penicillin, and 100 µg mL⁻¹ streptomycin. Each cell suspension was obtained by treating the confluent monolayer formed on the tissue culture dish with 0.25% trypsin (Invitrogen). The cells were cultured under a humidified atmosphere of 5% CO₂ and 95% air at 37 °C.