Fetal bovine serum (fbs)

Immediately after surgical resection of the tumor, several tissue blocks (approximately 0.5 cm) were removed from the center of the tumor mass to avoid blood vessels. The tissue blocks were placed in RPMI1640 medium (iCell, Shanghai, China), sealed and stored at 4 °C, and transported to the laboratory within 1 h. Tumor tissues were washed three times with D-Hanks solution (Solarbio, Beijing, China) and dissected into 1 mm³ samples in a culture dish. The tissue was mixed with 5 mL type II collagenase (final concentration of 1 mg/mL; Solarbio), followed by digestion for 1.5 h in a 37 °C water bath (Figure 7C). Digestion was terminated by adding 5 mL culture medium and centrifugation at 1000 rpm for 5 min. The cell suspension was filtered twice through a 200-mesh filter. Finally, the RPMI1640 complete medium was added, and the cell suspension was transferred to T25 culture flasks. The complete medium was supplemented with 15% FBS (iCell), 1% penicillin-streptomycin solution (iCell), 1× L-glutamine (iCell), and 20 ng/mL basic fibroblast growth factor (bFGF, iCell). During the culture period, cells were incubated in a humidified incubator at 37 °C with 5% CO₂, and the medium was changed every 2 d. The primary cell line was named PriGIST, and the PriGIST cells were divided into two parts: one was introduced with genes for immortalization, and the other was used as a control.

Porcine kidney cells (PK15 cells) were preserved in the house. Porcine skeletal muscle satellite cells (PSC cells) were purchased from iCell Bioscience Inc. (Shanghai, China). PK15 cells were maintained in Dulbecco’s modified eagle media (DMEM) (Gibco, Thermo Fisher Scientific, Shanghai, China) supplied with 10% fetal bovine serum (FBS) (Gibco, Thermo Fisher Scientific, Shanghai, China) and 1% penicillin/streptomycin (Thermo Fisher Scientific, Shanghai, China). PSC cells were maintained in skeletal muscle cell complete medium (PriMed-iCell-018, iCell Bioscience Inc., Shanghai, China) supplied with 10% FBS (iCell Bioscience Inc., Shanghai, China), 1% penicillin/streptomycin (iCell Bioscience Inc., Shanghai, China), and 1% additive (iCell Bioscience Inc., Shanghai, China). The cells were cultured in a 37 °C incubator with 5% CO₂.

We collected scar tissues within 6 h of surgery and soaked it in phosphate buffer saline (PBS) with 2% penicillin/streptomycin (P/S) for 5 min. The epidermis and hypodermis were mechanically removed from the scar tissue with a scalpel. The remaining dermis was minced into 1 mm³ pieces in sterile culture dishes. These pieces were then transferred to culture dishes precoated with fetal bovine serum (FBS, Gibco) and incubated in complete Dulbecco's modified Eagle's medium (DMEM, Gibco) for 7 days in a humidified atmosphere at 37°C, 5% CO₂ until the cells reached 70%–80% confluence.
³¹ (link) Passages 5–15 were used for subsequent experiments and named as scar‐derived fibroblasts (SCF).
Human skin fibroblast cell line (HSF, iCell) was cultured under 37°C in 5% CO₂ conditions in complete medium (DMEM + 10% FBS + 2% P/S). Passages 5–15 were used for the following experiment.
Human umbilical vein endothelial cells (EC, iCell) were cultured in endothelial cell medium (EDCM, Sciencell) at 37°C, 5% CO₂. Passages 2–8 were used for the following experiment.