Aspirin triggers ferroptosis in hepatocellular carcinoma cells through restricting NF-κB p65-activated SLC7A11 transcription.

A number of studies have shown that aspirin, as commonly prescribed drug, prevents the development of hepatocellular carcinoma (HCC). Ferroptosis as a dynamic tumor suppressor plays a vital role in hepatocarcinogenesis. In this study we investigated whether aspirin affected ferroptosis in liver cancer cells. RNA-seq analysis revealed that aspirin up-regulated 4 ferroptosis-related drivers and down-regulated 5 ferroptosis-related suppressors in aspirin-treated HepG2 cells. Treatment with aspirin (4 mM) induced remarkable ferroptosis in HepG2 and Huh7 cells, which was enhanced by the ferroptosis inducer erastin (10 µM). We demonstrated that NF-κB p65 restricted ferroptosis in HepG2 and Huh7 cells through directly binding to the core region of SLC7A11 promoter and activating the transcription of ferroptosis inhibitor SLC7A11, whereas aspirin induced ferroptosis through inhibiting NF-κB p65-activated SLC7A11 transcription. Overexpression of p65 rescued HepG2 and Huh7 cells from aspirin-induced ferroptosis. HCC patients with high expression levels of SLC7A11 and p65 presented lower survival rate. Functionally, NF-κB p65 blocked the aspirin-induced ferroptosis in vitro and in vivo, which was attenuated by erastin. We conclude that aspirin triggers ferroptosis by restricting NF-κB-activated SLC7A11 transcription to suppress the growth of HCC. These results provide a new insight into the mechanism by which aspirin regulates ferroptosis in hepatocarcinogenesis. A combination of aspirin and ferroptosis inducer may provide a potential strategy for the treatment of HCC in clinic.

A universal gene carrier platform for treatment of human prostatic carcinoma by p53 transfection.

Our previous work showed that a charge-reversal layer-by-layer nanosystem, PEI/PAH-Cit/AuNP-CS, effectively facilitates cellular uptake of siRNA and enhances the silencing efficacy of MDR1 siRNA. Here, the plasmid loading capacity of this vehicle was examined using EGFP-N1, and the plasmid release profile was determined in response to pH changes. The cytotoxicity of the EGFP-N1/PEI/PAH-Cit/AuNP-CS complex against HeLa and 293T cells was almost negligible. PEI/PAH-Cit/AuNP-CS efficaciously delivered the plasmids EGFP-N1 (encoding green fluorescent protein) and pGL3.0 (encoding luciferase) into 293T and HeLa cells, thus verifying the universality of PEI/PAH-Cit/AuNP-CS as a gene carrier. The results of an inverted fluorescence microscopy, flow cytometry (FCM) and western blotting methods demonstrated that PC-3 prostate cancer cells treated with EGFP-p53/PEI/PAH-Cit/AuNP-CS expressed higher levels of GFP than cells treated with EGFP-p53/PEI. Furthermore, PC-3 cells treated with EGFP-p53/PEI/PAH-Cit/AuNP-CS showed reduced cellular viability and increased nuclear fragmentation, consistent with elevated p53 expression. Propidium iodide (PI) flow cytometric assays were conducted to demonstrate that EGFP-p53/PEI/PAH-Cit/AuNP-CS elevated the level of apoptosis in PC-3 cells. Western blotting and caspase activation studies revealed that EGFP-p53/PEI/PAH-Cit/AuNP-CS complexes may induce PC-3 apoptosis via the mitochondria-mediated signaling pathway by up-regulation of Bax, down-regulation of Bcl-2, and activation of caspase-3.