Differential expression of transcriptional genes in paclitaxel-resistant mouse gastric adenocarcinoma cell lines

Paclitaxel is commonly used as a second-line treatment for gastric cancer, but the mechanisms underlying paclitaxel resistance remain to be further investigated. To address this, we successfully established a mouse gastric adenocarcinoma cell line (MPC) from murine gastric adenocarcinoma organoids. Subsequently, a paclitaxel-resistant cell line (MPC-PTX) was generated through multi-cycle drug stimulation. This model provides a valuable tool for studying the mechanisms of paclitaxel resistance in gastric cancer. The increasing drug concentration method was employed in this study to induce drug resistance in the cell line. Initially, the primary IC50 (pIC50) of the parent cell line was determined. When the cells reached 50% confluence, the MPC cells were exposed to the IC50 dose of paclitaxel (PTX). After 2 days of treatment, the medium was changed to fresh medium for culture for the next 5 days. Every 4 cycles of treatment, the treated PTX IC50 (tIC50) level of MTC was reassessed. MTC cells were treated with a new cycle of PTX at the tIC50 concentration. After ~30 cycles of PTX treatment, the drug resistance index (RI), defined as RI = tIC50/pIC50, exceeded 5, indicating successful establishment of a PTX-resistant cell line, which was named MPC-PTX. According to the methods mentioned above, MTC-R cells also underwent monoclonal selection, and the IC50 of PTX was remeasured.