Fraser extracellular matrix complex subunit 1 promotes liver metastasis of gastric cancer.

Liver metastasis is often fatal in patients with gastric cancer, therefore, we aimed to identify genes associated with the mechanisms of liver metastasis of gastric cancer (GC) and to investigate their potential to predict recurrence and to serve as targets of therapy. Recurrence pattern-specific transcriptome analysis was performed to identify liver metastasis-associated genes. A stable knockout cell line was generated to investigate metabolic pathways that contribute to the malignant phenotype in vitro and vivo. Three hundred GC patients were analyzed to demonstrate an association between gene expression levels and clinicopathological parameters. As a results extracellular matrix complex subunit 1 (FRAS1) was identified as a liver metastasis-associated gene. Pathway analysis revealed that FRAS1 expression was significantly correlated with the expression of genes encoding TGFB1, MAP1B, AHNAK, BMP2, MUC1, BIRC5, MET, CDH1, RB1 and MKI67. FRAS1 expression was associated with the activation of the EGFR and PI3K signaling pathways. The proliferation ability of FRAS1 knockout cell line (FRAS1-KO) was inhibited compared to that of the parent cell line through caspase activity increment and cell cycle alteration. FRAS1-KO cells exhibited increased responsiveness to oxygen stress and diminished stemness, invasiveness, and migration. Mouse models of GC revealed decreases in tumor formation and generation of metastasis by FRAS1-KO cells. Moreover, the cumulative liver recurrence rate was significantly increased in patients with GC with high FRAS1 expression levels. We concluded that FRAS1 contributes to the malignant phenotype of GC, especially liver metastasis, and may therefore serve as a predictive marker or a target for treating liver metastasis.