Targeting hepatoma using nitric oxide donor strategies

Area of Science:

• Hepatoma cell death mechanisms
• Nitric oxide signaling in cancer
• Tumor biology and therapy

Background:

• Hepatoma cells are a significant cause of cancer mortality.
• Nitric oxide (NO) plays a complex role in cell survival and death.
• Understanding NO's role in CD95-dependent apoptosis is crucial for cancer therapy.

Purpose of the Study:

• To investigate the effect of increased intracellular nitric oxide (NO) on CD95-dependent cell death in hepatoma cells.
• To analyze the impact of NO on cell death receptors, caspase activation, RhoA kinase activity, and p53 expression.
• To evaluate the antitumoral activity of NO in vivo using xenograft mouse models.

Main Methods:

• NO donors and NOS-3 overexpression were used to increase intracellular NO concentration.
• Analysis of cell death receptors, caspase activation, RhoA kinase activity, NOS-3 expression/activity, oxidative/nitrosative stress, and p53 expression.
• Xenograft mouse models with hepatoma cells (NOS-3 overexpressing or wild-type) were used to assess antitumoral effects.

Main Results:

• NO donors and NOS-3 overexpression increased CD95 expression and caspase activation in hepatoma cell lines.
• NOS-3 overexpression led to increased oxidative/nitrosative stress, p53 expression, and cell death.
• In vivo studies showed reduced tumor size and increased p53 and cell death receptor expression with NOS-3 overexpression or NO donor injection.

Conclusions:

• Increased intracellular NO concentration promotes oxidative/nitrosative stress, Rho kinase activity, p53 and CD95 expression, and cell death in hepatoma cells.
• NO-mediated mechanisms, including p53 and CD95 pathways, contribute to antitumoral effects.
• Intratumoral NO administration or NOS-3 overexpression demonstrates therapeutic potential against hepatoma in vivo.