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Updated: May 28, 2026
Application of Genetically Encoded Fluorescent Nitric Oxide (NO•) Probes, the geNOps, for Real-time Imaging of NO• Signals in Single Cells
Published on: March 16, 2017
Effects of nitric oxide synthase-3 overexpression on post-translational modifications and cell survival in HepG2
P Aguilar-Melero1, G Ferrín, J Muntané
1Liver Research Unit, IMIBIC (Instituto Maimónides para la Investigación Biomédica de Córdoba), Reina Sofia University Hospital, Córdoba, Spain. b92agmep@uco.es
Abstract:
Hepatocarcinoma is the fifth most common neoplasm and the third cause of cancer-related death. The development of genetic- and/or molecular-based therapies is urgently required. The administration of high doses of nitric oxide (NO) promotes cell death in hepatocytes. NO contributes to cell signaling by inducing oxidative/nitrosative-dependent post-translational modifications. The aim of the present study was to investigate protein modifications and its relation with alteration of cell proliferation and death in hepatoma cells. Increased intracellular NO production was achieved by stable nitric oxide synthase-3 (NOS-3) overexpression in HepG2 cells. We assessed the pattern of nitration, nitrosylation and carbonylation of proteins by proteomic analysis. The results showed that NOS-3 cell overexpression increased oxidative stress, which affected proteins mainly involved in cell protein folding. Carbonylation also altered metabolism, as well as immune and antioxidant responses. The interaction of nitrosative and oxidative stress generated tyrosine nitration, which affected the tumor marker Serpin B3, ATP synthesis and cytoskeleton. All these effects were associated with a decrease in chaperone activity, a reduction in cell proliferation and an increased cell death. Our study showed that alteration of nitration, nitrosylation and carbonylation pattern of proteins by NO-dependent oxidative/nitrosative stress was related to a reduction of cell survival in a hepatoma cell line.
Insights
High nitric oxide (NO) levels induce oxidative stress in hepatoma cells, altering protein modifications. This leads to reduced cell proliferation and increased cell death, suggesting NO-based therapies for liver cancer.
Area of Science:
- Hepatocellular carcinoma research
- Molecular oncology
- Proteomics and post-translational modifications
Background:
- Hepatocellular carcinoma (HCC) is a major global health concern, necessitating novel therapeutic strategies.
- Nitric oxide (NO) plays a dual role in cell signaling and can induce cell death at high concentrations.
- Understanding NO-mediated protein modifications is crucial for developing targeted HCC therapies.
Purpose of the Study:
- To investigate the impact of increased intracellular nitric oxide (NO) production on protein modifications in hepatoma cells.
- To correlate these protein alterations with changes in cell proliferation and cell death.
- To explore the potential of NO-dependent stress as a therapeutic target for liver cancer.
Main Methods:
- Overexpression of nitric oxide synthase-3 (NOS-3) in HepG2 hepatoma cells to increase intracellular NO.
- Proteomic analysis to assess protein nitration, nitrosylation, and carbonylation patterns.
- Evaluation of cell proliferation and cell death markers.
Main Results:
- NOS-3 overexpression elevated oxidative stress, impacting proteins involved in cell protein folding, metabolism, and immune responses.
- Nitrosative and oxidative stress interactions led to tyrosine nitration, affecting tumor markers (Serpin B3), ATP synthesis, and cytoskeleton.
- Observed decrease in chaperone activity, reduced cell proliferation, and increased cell death.
Conclusions:
- Altered protein nitration, nitrosylation, and carbonylation patterns due to NO-dependent stress are linked to reduced hepatoma cell survival.
- NO-induced post-translational modifications offer potential therapeutic targets for hepatocellular carcinoma.
- Targeting NO signaling pathways may represent a novel strategy for liver cancer treatment.
