Acid Sphingomyelinase Activation and ROS Generation Potentiate Antiproliferative Effects of Mitomycin in HCC

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Sphingolipids regulate hepatocellular apoptosis and proliferation.
• Sphingolipid metabolites are biomarkers for chronic liver disease and hepatocellular carcinoma.

Purpose of the Study:

• To investigate the effect of acid sphingomyelinase (ASM) overexpression on hepatocellular carcinoma (HCC) cell proliferation.
• To explore the role of ASM in mediating the antiproliferative effects of mitomycin.

Main Methods:

• Human HCC cell lines were transfected to overexpress ASM.
• Cells were treated with mitomycin, and ASM activity, sphingolipid levels, reactive oxygen species (ROS), and cell proliferation were measured.
• mRNA expression of ceramidases and sphingosine kinases was analyzed.

Main Results:

• Mitomycin treatment significantly increased ASM activity, ceramide accumulation, and ROS generation in ASM-overexpressing cells.
• Cell proliferation was significantly reduced in ASM-overexpressing cells, an effect reversed by antioxidants.
• Mitomycin altered mRNA levels of ceramidases and sphingosine kinases.

Conclusions:

• ASM overexpression enhances the antiproliferative effect of mitomycin in HCC cells.
• Ceramide and ROS accumulation mediate this enhanced effect.
• Targeting ASM could be a novel therapeutic strategy for HCC.