Ham s f 12

The human GC cell lines MGC80-3 and AGS were purchased from Shanghai Cell Bank (Shanghai, China). Cells were cultured in RPMI-1640 or Ham’s F-12 (Procell, Wuhan, China) supplemented with 10% fetal bovine serum (FBS) (Gibco BRL, Gaithersburg, MD, United States) and antibiotics (100 IU/mL penicillin and 100 μg/mL streptomycin) at 37 °C in a humidified atmosphere with 5% CO₂. Short hairpin RNA for LINC01268 (NR_038863) was ligated into the GV493 plasmid (GeneChem, Shanghai, China). The sh-LINC01268 or nonspecific sh-negative control (sh-NC) plasmid was transfected into MGC80-3 and AGS cells using X-tremeGENE HP DNA Transfection Reagent (Roche, Germany). After infection for 48 h, the infected cells were harvested for the extraction of total RNA and protein.

Seven fresh frozen cancer tissues and corresponding paracancerous tissue samples were randomly selected from GC patients who underwent radical GC resection in the HMU Cancer Hospital from January 2019 to April 2019. The selected samples had complete clinicopathological data, including gender, age, degree of differentiation, tumor node metastasis (TNM) stage, primary tumor size, and lymph node metastasis. The Institutional Review Committee of Harbin Medical University Cancer Hospital approved this study. All samples were collected with the patient's written informed consent. The gastric epithelial cell line GES‐1 and GC cell lines AGS, BGC‐823, HGC‐27, and MKN‐28 were provided by Procell Life Science & Technology Co. Ltd. (Wuhan, PR China). AGS cells were cultured in Ham's F‐12 (Procell, PR China) and the other cells in RPMI‐1640 (Procell, Wuhan, PR China). All media were supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin solution. All cells were incubated at 37 °C and 5% CO₂.