FXYD5 regulates gastric cancer cell metastasis and drug resistance by EMT modulation.

Gastric cancer (GC) is the third leading cause of cancer-related mortality and the fourth most prevalent malignancy globally. The high prevalence and mortality rates of GC are attributed to various factors, including drug resistance, local recurrence, and distant metastases. There is an urgent need to identify novel therapeutic targets for GC. Patient-derived xenografts (PDX) model offers unique advantages in maintaining the molecular heterogeneity and tumor microenvironment of primary tumors, offering significant advantages for the screening of personalized therapeutic targets. In this study, we established GC PDX models with metastatic potential through orthotopic transplantation and investigated the different gene expressions between primary and metastatic tumors using PCR-array analysis. We found that the metastatic tumors displayed elevated levels of FXYD domain-containing ion transport regulator 5 (FXYD5) compared to the primary tumors. Additionally, reducing FXYD5 expression was found to inhibit the invasion, metastasis, and proliferation of GC cells. Silencing FXYD5 also reversed the resistance of GC cells to doxorubicin and vincristine by modulating the epithelial-mesenchymal transition (EMT) process and the expression of multidrug resistance protein 2. This study indicates that FXYD5 is involved in GC progression and regulates chemotherapy resistance, suggesting its potential as a novel therapeutic target for the clinical treatment of GC.