Sympathetic and parasympathetic innervation in hepatocellular carcinoma

Autonomic nervous system plays an important role in the development of multiple cancers via regulating cancer cell proliferation, differentiation, apoptosis, migration and invasion. However, no detailed studies have been performed to study the role of autonomic nerve fibers in hepatocellular carcinoma (HCC) as well as its correlation with the progression of HCC. Here, we examined the distribution of the autonomic nerve fibers and analyzed the correlation between autonomic nerve fibers and the pathological characteristics of HCC patients. The transcriptional expression of adrenergic and cholinergic receptors was evaluated in both hepatoma cell lines and primary hepatoma cells. In addition, we summarized the function of receptors for neurotransmitters in different cancers recently reported. Our findings indicate that tissue of liver cancer is innervated by both sympathetic and parasympathetic nerves and the density of the nerve fibers is associated with patients' poor prognosis. Additionally, we report that adrenergic receptors beta 2 and cholinergic receptors alpha 7, M1 and M3 are high expressed in both hepatoma cell lines and primary hepatoma cells, indicating these receptors may play essential roles in the regulation of autonomic nervous system triggered HCC.