Sulfasalazine induces ferroptosis by regulating the PIAS3/JAK1/STAT3 pathway to prevent brain metastases of hepatocellular carcinoma

Sulfasalazine (SAS) has a certain inhibitory effect on cancer, but its therapeutic effect on intracranial metastasis of hepatocellular carcinoma (HCC) remains unclear. The purpose of this study was to explore whether SAS has a beneficial effect on intracranial metastasis of HCC and reveal its potential molecular mechanism. HCC cells were treated with SAS, and PIAS3/JAK1/STAT3 was regulated by siRNA, pcDNA 3.1 overexpression vector, and JAK inhibitors. The regulatory effects of SAS on the PIAS3/JAK1/STAT3 axis were evaluated by loss- and gain-of-function and rescue experiments. Cancer cells were evaluated by C11-BODIPY probe, MDA detection, iron ion detection, and LPO detection. Proliferation was assessed by clonal formation assay, apoptosis by flow cytometry, invasion and migration by Transwell assay, and EMT-associated protein expression by western blot. The ability of cancer cells to metastasize was evaluated by blood–brain barrier model and xenografted mouse model. SAS effectively hampered HCC cell proliferation, invasion, and migration and EMT process, induced apoptosis and ferroptosis of HCC cells, and prevented brain metastases (BMS) of HCC cells. SAS inhibited JAK1/STAT3 pathway activation in HCC cells by upregulating PIAS3. JAK1 inhibitor enhanced the impact of SAS on HCC, while PIAS3 had the opposite action. SAS blocks JAK1/STAT3 pathway by upregulating PIAS3, thereby inducing ferroptosis and inhibiting BMS in HCC. Combined administration of SAS and JAK inhibitors may be a potential strategy for HCC with brain metastases.