Snu 216

Twelve types of GC cells (AGS, KATO-3, MKN-28, MKN-45, NCI-N87, SNU-5, SNU-216, SNU-484, SNU-668, YCC-1, YCC-6, and YCC-16) and normal human lung cells IMR-90 were purchased from American Type Culture Collection (Manassas, VA, USA), and three normal cell lines (GES-1, L-02, and 293T) were purchased from Saiqi Biotech Co., Ltd (Shanghai, China). AGS, KATO-3, MKN-28, MKN-45, SNU-5, SNU-216, SNU-484, SNU-668, IMR-90, and L-02 cells were maintained in RPMI 1640 medium (Gibco, Waltham, MA, USA). NCI-N87, YCC-1, YCC-6, YCC-16, GES-1, and 293T cells were grown in Dulbecco’s Modified Eagle Medium (Gibco) supplemented with 10% fetal bovine serum (Gibco), 100 U/mL penicillin (Gibco), and 100 μg/mL streptomycin (Gibco). All cells were cultured in a humidified atmosphere of 5% CO₂ incubator (Sanyo, Osaka, Japan) at 37°C, and the number of cells maintained at 80%.

The gastric cancer cell lines AGS, SNU-216, NCI-N87, SNU-620, SNU-638, SNU-668, NUGC-3, and MKN-74 were purchased from the Korean Cell Line Bank (Cancer Research Center, Seoul National University, Seoul, Korea) and grown in RPMI1640 medium (Gibco) supplemented with 5% fetal bovine serum (Gibco) and 100 μg/ml antibiotics (100 U/ml penicillin and 100 μg/ml streptomycin, Gibco). Cells (1 × 10⁵ cells/well) were plated in 24-well cell culture plates and grown at 37°C in a humidified, 5% CO₂/air atmosphere.

Human gastric cancer (GC) cell lines (MKN45, HGC27, SGC7901, BGC823, N87, SNU216 and MGC803) were purchased from the Cell Centre of the Chinese Academy of Sciences (Shanghai, China). Cells were cultured in RPMI-1640 (Invitrogen, Carlsbad, CA, USA) containing 10% heat-inactivated foetal bovine serum (FBS) (Invitrogen), 100 U/mL penicillin and 100 ng/L streptomycin and incubated in a 5% carbon dioxide humidified atmosphere at 37°C. Experiments were performed using cells in the logarithmic phase of growth. Small interfering RNA (siRNA) targeting beclin1 was purchased from Genepharma (Shanghai, China). The primer sequences of the beclin1 siRNAs were 5′‐CTCACAGCTCCATTACTTA‐3′ (beclin1‐KD1) and 5′‐TCAGGAGAGGAGCCATTTA‐3′ (beclin1‐KD2); negative control siRNAs were provided by the same manufacturer. The SNU216 cells were cultured in six-well plates to 60–70% confluence and then transfected with Lipofectamine 3000 (Invitrogen), according to the manufacturer’s protocol. The complete medium containing 1 μg/mL of puromycin (Gibco, Grand Island, NY, USA) was used to select the beclin1 knockdown cell lines.