Abstract：Objective： To explore the regulation and mechanism of microRNA-27a-3p (miR-27a-3p) on ferroptosis of colorectal cancer cell line HT-29 and SW480. Methods： Colorectal cancer cell lines HT-29 and SW480 were treated with 0, 25 and 5 μmol/L Erastin, respectively. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the mRNA expression of solute carrier family 7 member 11 (SLC7A11) in each group and the optimal concentration of Erastin was screened. HT-29 and SW480 cells were divided into siControl group, siSLC7A11-1 group and siSLC7A11-2 group, and transfected with control siRNA, siSLC7A11-1 and siSLC7A11-2, respectively. The cells were co-cultured with 5 μmol/L Erastin for 0, 24, 48 and 72 h to detect the cell proliferation activity and the level of malondialdehyde in the cells at different time points. HT-29 and SW480 cells were divided into miR-NC group, miR-27a-3p group and anti-miR-27a-3p group, respectively, and transfected with miR-NC, miR-27a-3 mimics and miR-27a-3p inhibitors, respectively. The mRNA expression level of SLC7A11 was detected by qRT-PCR, and the luciferase reporter gene assay was used to detect the luciferase activity of SLC7A11 3′UTR sequence (SLC7A11-WT) and mutant sequence (SLC7A11-Mut). The cells were co-cultured with 5 μmol/L Erastin for 0, 24, 48 and 72 h, and the cell proliferation activity was detected at different time points, and the intracellular malondialdehyde level was detected. Results： The mRNA expression of SLC7A11 in colorectal cancer HT-29 and SW480 cells was significantly increased with the increase of Erastin concentration (P<0.01). In colorectal cancer HT-29 and SW480 cells, compared with the siControl group, the cell proliferation activity in siSLC7A11-1 and siSLC7A11-2 groups was significantly increased at 48 h and 72 h (P<0.05), with a significant decrease in malondialdehyde levels (P<0.05). Compared with the miR-NC group, cell proliferation activity in miR-27a-3p group was significantly enhanced (P<0.05), while malondialdehyde levels and luciferase activity of SLC7A11-WT group were significantly decreased (P<0.05 or P<0.01), and luciferase activity of SLC7A11-Mut group showed no significant changes(P>0.05); and the cell viability of anti-miR-27a-3p group was significantly decreased (P<0.01), the level of malondialdehyde and the luciferase activity of SLC7A11-WT were significantly increased (P<0.01), and the luciferase activity of SLC7A11-Mut was not significantly changed (P>0.05). Conclusion： miR-27a-3p may regulate Erastin-induced ferroptosis in colorectal cancer cells by targeting the 3′UTR of SLC7A11 mRNA.
［Key words］colorectal cancer; ferroptosis; miR-27a-3p; solute carriers 7A11
