Analysis of gene expression changes in patient-derived gastric cancer cells after anticancer drug treatment or ALDH1A3 knockdown

Tumors consist of heterogeneous cell population, containing cancer cell subpopulations with anticancer drug-resistant property, called “persister” cells. To reveal the character of the persister cells, we analyzed gene expression profile of patient-derived gastric cells and residual cancer cells after treatment with 5-FU or SN38, an active metabolite of irinotecan. In our study, we identified ALDH1A3 as a marker and a cell proliferation factor of persister cells. To examine molecular pathways regulated by ALDH1A3, we analyzed gene expression profile of patient-derived gastric JSC15-3 in which ALDH1A3 was knocked down by using shRNAs. We treated patient-derived gastric cancer JSC15-3, JSC17-2 and JSC17-7 cells with 5-FU or SN38. We analyzed gene expression of control (DMSO) or drug-treated cells. Meanwhile, we introduced shRNAs by using lentivirus and selected the infected cells by 1 mg/mL puromycin. We analyzed gene expression in control cells (non-targeting shRNA [NC]) and ALDH1A3 -knocked down cells.