Cancer‐associated orthotopic myofibroblasts stimulates the motility of gastric carcinoma cells

Tumor progression has been recognized as the product of evolving crosstalk between cancer cells and the surrounding stromal cells. Cancer‐associated orthotopic myofibroblasts may be linked to the progression of gastric carcinomas. To understand the significance of orthotopic myofibroblasts, we examined the effects of cancer‐associated orthotopic myofibroblasts on the malignant phenotype of gastric cancer cells. Three human gastric cancer cell lines (OCUM‐2MD3, OCUM‐12, MKN‐45) and four human gastric fibroblast cell lines (cancer‐associated orthotopic fibroblast [CaF]‐29, CaF‐33, normal orthotopic fibroblast [NF]‐29, NF‐33) were used. The cancer‐associated orthotopic fibroblast cell lines CaF‐29 and CaF‐33 were established from a tumoral gastric wall, and normal orthotopic fibroblast NF‐29 and NF‐33 were established from a non‐tumoral gastric wall. Fibroblasts that were α‐smooth muscle actin‐positive were defined as myofibroblasts. We examined the effects of cancer‐associated orthotopic myofibroblasts on the aggressiveness of gastric cancer cells by wound‐healing assay, invasion assay, and RT‐PCR. The ratios of myofibroblasts in CaF‐29 (33%) and CaF‐33 (46%) were significantly (P