Effect of RAB25 knockdown on ferroptosis of colorectal cancer cells

Abstract

Objective: To investigate the effect of RAB25 on the sensitivity of erastin-induced ferroptosis in colorectal cancer(CRC). Methods: The GEPIA database was used to analyze the mRNA expression levels of RAB25 in CRC tissues and the co-expression between RAB25 and ferroptosis related genes. The lentivirus-mediated RAB25 knockdown cell line was constructed. The expression of RAB25 was detected by quantitative real-time polymerase chain (qRT-PCR) and western blotting. After adding erastin at different concentrations(0-20 μmol/L), the cell proliferation rate was measured by CCK8 assay. The cell morphology and the mitochondrial structure were observed by inverted fluorescence microscope and transmission electron microscope, respectively. C11-BODIPY staining and flow cytometry probe were used to determine the level of lipid peroxides in cellular membranes. The combined effect of erastin and cetuximab on cellular viability in RAB25 knockdown cells were investigated. Results: The mRNA expression of RAB25 was unregulated in colorectal cancer tissues (P<0.01). The mRNA expression of RAB25 was correlated with some vital ferroptosis-associated genes. When erastin ≥10 μmol/L, the shRAB25 group inhibited the killing effect of ferroptosis on cell viability (P<0.000 1) compared to that of the control group, and cell morphology and mitochondrial structure were clearer and complete in the shRAB25 group. Flow cytometry revealed a significant decrease in lipid peroxidation levels in the shRAB25 group(P<0.000 1) compared to the control group. The expression of shRAB25 enhanced the toxic effects by erastin and cetuximab combination. Conclusions: RAB25 is highly expressed in colorectal cancer tissues and played an significant role in ferroptosis. After silencing RAB25, the erastin-induced lethal effect of colorectal cancer cells was inhibited. RAB25 and erastin may induce ferroptosis synergistically, enhancing the efficacy of cetuximab

Keywords

• |colorectal cancer|ras-associated binding protein 25|ferroptosis