Antitumoral gene-based strategy involving nitric oxide synthase type III overexpression in hepatocellular carcinoma

Area of Science:

• Hepatocellular Carcinoma Research
• Gene Therapy
• Molecular Biology

Background:

• Hepatocellular carcinoma (HCC) develops in cirrhotic livers, posing a significant clinical challenge.
• Nitric oxide synthase type III (NOS-3) overexpression has shown potential to induce cell death in hepatoma cells.

Purpose of the Study:

• To develop and evaluate a gene therapy strategy for specifically overexpressing NOS-3 in HCC cells.
• To assess the efficacy of NOS-3 gene therapy in vitro and in vivo models of HCC in fibrotic livers.

Main Methods:

• Developed first-generation adenoviruses to overexpress NOS-3 or green fluorescent protein, regulated by alpha-fetoprotein (AFP) and Rous Sarcoma Virus (RSV) promoters.
• Utilized cultured Hepa 1-6 cells and orthotopically implanted tumors in CCl4-induced fibrotic mouse livers for in vitro and in vivo experiments.
• Administered adenoviruses via tail vein injection and analyzed effects on cell death markers, DNA damage, p53, CD95/CD95L, and caspase activities.

Main Results:

• AFP-NOS-3/RSV-luciferase adenovirus increased oxidative DNA damage, p53, CD95/CD95L expression, and caspase activities in cultured Hepa 1-6 cells.
• NOS-3 overexpression led to increased cell death markers and reduced proliferation of established HCC tumors in fibrotic livers.
• The observed effects were linked to increased oxidative/nitrosative stress induced by NOS-3.

Conclusions:

• Overexpression of NOS-3 via gene therapy effectively induces DNA damage, p53 activation, CD95/CD95L expression, and cell death in HCC cells.
• The developed gene therapy strategy demonstrates significant effectiveness both in vitro and in vivo for treating HCC in fibrotic livers.