Abstract: Objective To investigate the effect and mechanism of Sulfiredoxin-1 (SRXN1) on ferroptosis in hepatocellular carcinoma cells. Methods Cultured HepG2 cells were divided into the following three groups: negative control group (NC group, treated with dimethyl sulfoxide), eristin group (treated with 10 μM eristin, a ferroptosis inducer ), and si-SRXN1 group (si-SRXN1 group, treated with small interfering RNA of SRXN1 and erasin). The iron content of each group was assayed by the iron content assay kit; The reactive oxygen species (ROS) and MDA levels of each group was detected with enzyme-linked immunosorbent assay (ELISA); The mRNA expression level of SRXN1, GPX4, SLC7A11, ACSL4, and LPCAT3 genes was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR); The expression level of SRXN1 protein was evaluated by Western-blot. Results Compared with the NC group, the cellular iron content [(8.46±0.60) vs (13.64±0.37)], ROS and MDA levels [(132.04±15.21) vs (203.82±13.17), and (97.35±9.58) vs (209.32±8.78)], the mRNA expression levels of ACSL4 and LPCAT3 [(1.00±0.06) vs (2.15±0.03), (1.00±0.02) vs (1.58±0.02)], as well as the expression levels of SRXN1 mRNA [(1.00±0.05) vs (2.94±0.16)] and protein [(0.88±0.02) vs (1.18±0.03)] were all significantly enhanced in the eristin group (P<0.01), whereas the expression of GPX4 and SLC7A11 were both prominently diminished in the eristin group [(1.00±0.03) vs (0.33±0.02), (1.00±0.08) vs (0.33±0.01)] (all P<0.0001). When compared with the eristin group, the cellular iron content [(13.64±0.37) vs (20.91±0.96)], ROS and MDA levels [(203.82±13.17) vs (261.38±16.92), (209.32±8.78) vs (293.86±7.65)], mRNA expression levels of ACSL4 [(2.15±0.03) vs (2.70±0.09)] and LPCAT3 [(1.58±0.02) vs (1.86±0.08)] were all substantially ascended (all P<0.01), but the mRNA expression levels of GPX4 [(0.33±0.02) vs (0.10±0.01)] and SLC7A11 [(0.33±0.01) vs (0.14±0.001)], as well as the expression levels of SRXN1 mRNA [(2.94±0.16) vs (0.48±0.02)] and protein [(1.18±0.03) vs (0.64±0.06)] were all dramatically declined in the si-SRXN1 group,(P<0.01). Conclusion Knocking-down SRXN1 elevates cellular iron content, promotes oxidative stress response, and aggravates ferroptosis in hepatocellular carcinoma cells induced by eristin, which may be related to an inhibition of GPX4 and SLC7A11 genes expression, therefore attenuate antioxidant capacity and activating the expression of ACSL4 and LPCAT3 genes to promote the formation of lipid peroxidation.

Key words: Sulfiredoxin-1, Hepatocellular carcinoma cells, Ferroptosis