The nervous system: a new target in the fight against cancer

Venlafaxine antagonizes the noradrenaline-promoted colon cancer progression by inhibiting the norepinephrine transporter

Epidemiological studies have demonstrated that the use of antidepressants is associated with a decreased risk of colorectal cancer (CRC); however, the mechanisms behind this association are yet unknown. Adrenergic system contributes to the stress-related tumor progression, with norepinephrine (NE) mainly secreted from adrenergic nerve fibers. Norepinephrine serotonin reuptake inhibitors are successfully used antidepressants. This study demonstrates that a widely used antidepressant venlafaxine (VEN) antagonizes NE-promoted colon cancer in vivo and in vitro. Bioinformatic analysis suggested that NE transporter (NET, SLC6A2), a target of VEN, was closely associated with the prognosis of clinical patients with CRC. In addition, the knockdown of NET antagonized the effect of NE. The NET-protein phosphatase 2 scaffold subunit alpha/phosphorylated Akt/vascular endothelial growth factor pathway partially mediates the antagonizing effect of VEN on NE's actions in colon cancer cells. These were also confirmed by in vivo experiments. Our findings revealed for the first time that, in addition to its primary function as a transporter, NET also promotes NE-enhanced colon cancer cell proliferation, tumor angiogenesis, and tumor growth. This provides direct experimental and mechanistic evidence for the use of antidepressant VEN in the treatment of CRC and a therapeutic potential for repurposing existing drugs as an anti-cancer approach to improve the prognosis of patients with CRC.

On the Core Prescriptions and Their Mechanisms of Traditional Chinese Medicine in Hepatitis B, Liver Cirrhosis, and Liver Cancer Treatment

Background

As a frequent cause of death in cancer patients, liver cancer usually occurs in hepatitis B and cirrhosis. In China, Chinese people have been using traditional Chinese medicine (TCM) in treating various chronic liver diseases, which could effectively improve the symptoms and slow down the progression of liver diseases. However, due to the complexity rules of TCM prescription, their action mechanisms are still not clearly understood, which may affect the popularization of effective prescriptions. This study aims to identify the core TCM herbs in the treatment of hepatitis B, liver cirrhosis, and liver cancer so as to clarify the mechanism of action of the core herb networks.

Methods

There were 1,673 prescriptions for chronic liver diseases collected in this study, of which 854 were hepatic B prescriptions, 530 were for liver cirrhosis, and 289 were for liver cancer. The basic characteristics of herbal medicine were firstly explained via descriptive analysis, then the core prescriptions of herbal medicine were analyzed through association rule, and finally, the mechanism of core prescriptions was explored with the help of systematic network pharmacology and by applying such databases as TCMIP, HERB, OMIM, GeneCards, KEGG, and software like RStudio and Cytoscape.

Results

The rule of the core prescriptions in these cases was characterized by the application of herbs with both cold and warm properties, in which bitter herbs with cold property took priority. Tonifying deficiency, clearing heat, and activating blood circulations to remove stasis were common treatment principles for the three liver diseases. Turmeric Root Tuber (YuJin), White Peony Root (BaiShao), Bupleurum (ChaiHu), Salvia miltiorrhiza (DanShen), and Astragali Radix (HuangQi) were prescribed the most in hepatitis B treatment to invigorate the spleen and soothe the liver. Astragali Radix (HuangQi), Tuckahoe (FuLing), Atractylodis Macrocephalae Rhizoma (BaiZhu), Fructus Polygoni Orientalis (ShuiHongHuaZi), and Curcumae Rhizome (EZhu) were most frequently applied in liver cirrhosis treatment to replenish qi and activate blood. Oldenlandia (BaiHuaSheSheCao), Bearded Scutellaria (BanZhiLian), Curcumae Rhizome (EZhu), and Cardamom (DouKou) were most frequently prescribed to eliminate cancer toxin, invigorate the spleen, and activate blood. These core herbs mainly act through signal transduction and immune system pathways, in which the PI3K-Akt pathway plays a key role. The core prescription for liver cirrhosis regulated more endocrine system pathways than the hepatitis B prescription, and liver cancer prescription regulated more nervous system-related pathways.

Conclusion

Three core prescriptions for hepatitis B, liver cirrhosis, and liver cancer treatment were identified, which acted mainly through signal transduction and immune system pathways to regulate immunity and cell growth and participate in inflammation inhibition, in which liver cancer prescription regulated more pathways, especially more nervous system-related pathways than the other two.