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Updated: Jun 28, 2025

An Oncogenic Hepatocyte-Induced Orthotopic Mouse Model of Hepatocellular Cancer Arising in the Setting of Hepatic Inflammation and Fibrosis
Published on: September 12, 2019
Tyrosine hydroxylase inhibits HCC progression by downregulating TGFβ/Smad signaling
Guoqian Liu1,2, Mengwei Li1,2, Zimei Zeng2
1Key Laboratory of Molecular Radiation Oncology Hunan Province, Changsha, 410008, Hunan, China.
Abstract:
The alteration of metabolic processes has been found to have significant impacts on the development of hepatocellular carcinoma (HCC). Nevertheless, the effects of dysfunction of tyrosine metabolism on the development of HCC remains to be discovered. This research demonstrated that tyrosine hydroxylase (TH), which responsible for the initial and limiting step in the bio-generation of the neuro-transmitters dopamine and adrenaline, et al. was shown to be reduced in HCC. Increased expression of TH was found facilitates the survival of HCC patients. In addition, decreased TH indicated larger tumor size, much more numbers of tumor, higher level of AFP, and the presence of cirrhosis. TH effectively impairs the growth and metastasis of HCC cells, a process dependent on the phosphorylation of serine residues (S19/S40). TH directly binds to Smad2 and hinders the cascade activation of TGFβ/Smad signaling with the treatment of TGFβ1. In summary, our study uncovered the non-metabolic functions of TH in the development of HCC and proposes that TH might be a promising biomarker for diagnosis as well as an innovative target for metastatic HCC.
Insights
Tyrosine hydroxylase (TH) is reduced in liver cancer (HCC), but higher TH levels improve patient survival. This enzyme inhibits HCC growth and metastasis, suggesting TH as a diagnostic biomarker and therapeutic target.
Area of Science:
- Biochemistry
- Oncology
- Molecular Biology
Background:
- Metabolic alterations are crucial in hepatocellular carcinoma (HCC) development.
- The role of tyrosine metabolism dysfunction in HCC remains unclear.
Purpose of the Study:
- To investigate the function of tyrosine hydroxylase (TH) in hepatocellular carcinoma (HCC).
- To explore TH as a potential biomarker and therapeutic target for HCC.
Main Methods:
- Quantification of TH expression in HCC tissues.
- Analysis of the correlation between TH levels and clinical parameters.
- Investigation of TH's effect on HCC cell growth and metastasis in vitro.
- Exploration of TH's interaction with the TGFβ/Smad signaling pathway.
Main Results:
- TH expression is reduced in HCC, and higher TH levels correlate with improved patient survival.
- Decreased TH is associated with larger tumor size, increased tumor number, higher AFP levels, and cirrhosis.
- TH inhibits HCC cell proliferation and metastasis by impairing serine phosphorylation (S19/S40).
- TH directly binds Smad2, inhibiting TGFβ/Smad signaling activation.
Conclusions:
- TH possesses non-metabolic functions critical to HCC development.
- TH may serve as a valuable diagnostic biomarker for HCC.
- TH represents a potential therapeutic target for metastatic HCC.
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