[Effect of Staphylococcal Nuclease and Tudor Domain Containing 1/SLC7A11 on the Occurrence and Development of Osteosarcoma by Inhibiting Ferroptosis].

Objective To investigate the effect of staphylococcal nuclease and tudor domain containing 1(SND1) on the biological function of osteosarcoma cells and decipher the mechanism of SND1 in regulating ferroptosis in osteosarcoma cells via SLC7A11. Methods Human osteoblasts hFOB1.19 and osteosarcoma cell lines Saos-2,U2OS,HOS,and 143B were cultured,in which the expression level of SND1 was determined.Small interfering RNA was employed to knock down the expression of SND1(si-SND1) in the osteosarcoma cell line HOS and 143B.The CCK8 assay kit,colony formation assay,and Transwell assay were employed to examine the effect of SND1 expression on the biological function of osteosarcoma cells.Furthermore,we altered the expression of SND1 and SLC7A11 in osteosarcoma cells to investigate the effect of SND1 on osteosarcoma ferroptosis via SLC7A11. Results The mRNA and protein levels of SND1 in Saos-2,U2OS,HOS,and 143B cells were higher than those in hFOB1.19 cells(all P <0.01).Compared with the control group,transfection with si-SND1 down-regulated the expression level of SND1 in HOS and 143B cells(all P <0.01),decreased the viability of HOS and 143B cells,reduced the number of colony formation,and inhibited cell invasion and migration(all P <0.001).The ferroptosis inducer Erastin promoted the apoptosis of HOS and 143B cells,while the ferroptosis inhibitor Ferrostatin-1 improved the viability of HOS and 143B cells(all P <0.001).After SND-1 knockdown,Erastin reduced the viability of HOS and 143B cells,while Ferrostatin-1 restored the cell viability(all P <0.001).After treatment with Erastin in the si-SND1 group,the levels of iron and malondialdehyde were elevated,and the level of glutathione was lowered(all P <0.001).The results of in vivo experiments showed that SND1 knockdown inhibited the mass of the transplanted tumor in 143B tumor-bearing nude mice( P <0.001).Knocking down the expression of SND1 resulted in down-regulated SLC7A11 expression(all P <0.001) and increased ferroptosis in HOS and 143B cells( P <0.001, P =0.020). Conclusions SND1 presents up-regulated expression in osteosarcoma cells.It may inhibit ferroptosis by up-regulating the expression of SLC7A11,thereby improving the viability of osteosarcoma cells.