Activation of Activator Protein 1 and Extracellular Signal-Regulated Kinases in Human Hepatocellular Transformation

Systematic analysis of the mechanism of Xiaochaihu decoction in hepatitis B treatment via network pharmacology and molecular docking

Hepatitis B (HB) is a globally prevalent infectious disease caused by the HB virus. Xiaochaihu decoction (XCHD) is a classic herbal formula with a long history of clinical application in treating HB. Although the anti-HB activity of XCHD has been reported, systematic research on the exact mechanism of action is lacking. Here, a network pharmacology-based approach was used to predict the active components, important targets, and potential mechanism of XCHD in HB treatment. Investigation included drug-likeness evaluation; absorption, distribution, metabolism, and elimination (ADME) screening; protein-protein interaction (PPI) network construction and cluster analysis; Gene Ontology (GO) analysis; and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Molecular docking was adopted to investigate the interaction between important target proteins and active components. Eighty-seven active components of XCHD and 155 anti-HB targets were selected for further analysis. The GO enrichment and similarity analysis results indicated that XCHD might perform similar or the same GO functions. Glycyrrhizae Radix (GR), one of the seven XCHD herbs, likely exerts some unique GO functions such as the regulation of interleukin-12 production, positive regulation of interleukin-1 beta secretion, and regulation of the I-kappaB/NF-kappaB complex. The PPI network and KEGG pathway analysis results showed that XCHD affects HB mainly through modulating pathways related to viral infection, immunity, cancer, signal transduction, and metabolism. Additionally, molecular docking verified that the active compounds (quercetin, chrysin, and capsaicin) could bind with the key targets. This work systematically explored the anti-HB mechanism of XCHD and provides a novel perspective for future pharmacological research.

Antiproliferative Effects of Alkaloid Evodiamine and Its Derivatives

Alkaloids, a category of natural products with ring structures and nitrogen atoms, include most U.S. Food and Drug Administration approved plant derived anti-cancer agents. Evodiamine is an alkaloid with attractive multitargeting antiproliferative activity. Its high content in the natural source ensures its adequate supply on the market and guarantees further medicinal study. To the best of our knowledge, there is no systematic review about the antiproliferative effects of evodiamine derivatives. Therefore, in this article the review of the antiproliferative activities of evodiamine will be updated. More importantly, the antiproliferative activities of structurally modified new analogues of evodiamine will be summarized for the first time.

FBXL5 targets cortactin for ubiquitination-mediated destruction to regulate gastric cancer cell migration

Cortactin, an actin-interacting protein, is implicated in cytoskeletal architecture and often amplified in several types of cancer including gastric adenocarcinomas. Downregulation of cortactin decreases cell migration and invasion. However, how to regulate cortactin in gastric cancer remains largely unknown. Here, we report that FBXL5 interacts with and targets cortactin for ubiquitylation and subsequent proteasomal degradation. Furthermore, we showed that FBXL5-induced cortactin degradation is mediated by extracellular regulated signal kinase (ERK). Serine phosphorylation sites mutant, cortactinS405A/S418A, prevent FBXL5-induced cortactin degradation. Moreover, CortactinS405A/S418A exhibited stronger effects in promoting gastric cancer cell migration when compared to wild-type cortactin. Taken together, our data suggested a novel molecular mechanism for the negative regulation of cortactin by FBXL5 in gastric cancer cells migration.

Evodiamine inhibits 12-O-tetradecanoylphorbol-13-acetate-induced activator protein 1 transactivation and cell transformation in human hepatocytes

Evodia rutaecarpa has been used to treat inflammatory digestive disorders in Asian countries. However, little is known about the antitumor activities of E. rutaecarpa and its bioactive constituent evodiamine (EVO). The aim of this study was to characterize the antitumor mechanisms of E. rutaecarpa and EVO in human hepatocytes. Human Chang liver cells were transfected with activator protein 1 (AP-1)-luciferase reporter gene and designated as Chang/AP-1 cells. The Chang/AP-1 cells were treated with E. rutaecarpa and its bioactive constituents, and challenged with the AP-1 stimulator 12-O-tetradecanoylphorbol-13- acetate (TPA). The present study showed that the methanol extract of E. rutaecarpa decreased the TPA-induced AP-1 transactivation in Chang/AP-1 cells, with an EC₅₀ value of 24.72 μg/mL. EVO inhibited the TPA-induced AP-1 transactivation and colony formation, with EC₅₀ values of 82 μM and 8.2 μM, respectively. Moreover, EVO significantly diminished the TPA-induced phosphorylation of extracellular signal-regulated kinases (ERKs). These results suggested that EVO treatment suppressed the TPA-induced AP-1 activity via the ERKs pathway. In conclusion, EVO inhibited the AP-1 activity and cellular transformation in human hepatocytes, suggesting that EVO was a potential agent for antitumor therapy.

Inhibitory effects of Zuo-Jin-Wan and its alkaloidal ingredients on activator protein 1, nuclear factor-κB, and cellular transformation in HepG2 cells

Zuo-Jin-Wan (ZJW) has been used to treat hepatocellular carcinoma in Asia. This study was to determine whether ZJW and its components blocked activator protein 1 (AP-1) and nuclear factor-κB (NF-κB) activities as well as tumor promotion in hepatoblastoma HepG2 cells. ZJW and its components, Coptis chinensis and Evodia rutaecarpa, inhibited AP-1 and NF-κB activities, and suppressed anchorage-independent growth of HepG2 cells. The major alkaloidal ingredients, berberine and evodiamine, inhibited AP-1 activities and/or NF-κB activation, and further suppressed hepatocellular transformation. In conclusion, ZJW and its constituents, berberine and evodiamine, suppressed tumor promotion primarily through AP-1 and/or NF-κB pathways in HepG2 cells.

Eriobotrya japonica leaf and its triterpenes inhibited lipopolysaccharide-induced cytokines and inducible enzyme production via the nuclear factor-kappaB signaling pathway in lung epithelial cells

Pulmonary inflammation is a characteristic of many lung diseases. Increased levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines, such as interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and IL-8, have been correlated with lung inflammation. In this study, we used lipopolysaccharide (LPS) to induce iNOS, COX-2, and cytokines (TNF-alpha, IL-1beta, and IL-8) productions in human lung epithelial cells (A-549). Leaf of Eriobotrya japonica (Pi-Pa-Ye, PPY), a traditional Chinese medicine for the treatment of pulmonary inflammatory diseases, was capable of suppressing LPS-induced cytokine productions in a dose-dependent manner. Moreover, the suppression of PPY on the cytokine productions resulted from the inhibition of inhibitory kappaB-alpha phosphorylation and nuclear factor-kappaB (NF-kappaB) activation. Analysis of the anti-inflammatory effects of ursolic acid and oleanolic acid, the triterpene compounds present in PPY, showed that ursolic acid significantly inhibited LPS-induced IL-8 production, NF-kappaB activation, and iNOS mRNA expression, whereas oleanolic acid did not have these effects. In conclusion, our findings suggested the potential mechanisms of PPY and its active component, ursolic acid, in the treatment of pulmonary inflammation.

Morin inhibits 12-O-tetradecanoylphorbol-13-acetate-induced hepatocellular transformation via activator protein 1 signaling pathway and cell cycle progression

Flavonoids are constituents of fruits, vegetables, and plant-derived beverages, as well as components in herbal containing dietary supplements. They exhibit a remarkable spectrum of biochemical and pharmacological activities. In this study, we examined morin (3,5,7,2',4'-pentahydroxyflavone) for its effect on 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated human hepatocytes. Morin inhibited TPA-induced cellular transformation in Chang liver cells in a dose-dependent manner. Luciferase assay and electrophoretic mobility shift assay revealed that morin suppressed TPA-induced AP-1 activity, and the inhibition of AP-1 activity by morin was mediated through the inhibition of p38 kinase. Moreover, morin induced the S-phase arrest and inhibited the DNA synthesis in TPA-treated hepatocytes, suggesting that a cell cycle checkpoint was activated by morin to block DNA synthesis in S phase. In conclusion, our results suggested that morin was a potent anti-hepatocellular transformation agent that inhibited cellular transformation by suppressing the AP-1 activity and inducing the S-phase arrest in human hepatocytes.

Transformation of immortalized colorectal crypt cells by microcystin involving constitutive activation of Akt and MAPK cascade

It has been shown by epidemiological and animal studies that microcystin is an important exogenous factor involved in the carcinogenesis of colorectal cancer (CRC). However, details of the mechanism remain unclear. Transformation of colorectal cells is an important initial step in carcinogenesis. Whether microcystin is capable of transforming immortalized colorectal crypt cells, and what the mechanism might be, was investigated. In the present study, we demonstrated that immortalized colorectal crypt cells could be transformed by microcystin. Transformed colorectal crypt cells showed an anchorage-independent growth phenotype, and the proliferation activities of microcystin-transformed cells were also greater than that of immortalized colorectal crypt cells. The Akt and the p38, JNK of mitogen-activated protein kinase (MAPK) pathways in microcystin-transformed cells were found to be constitutively activated. In microcystin-transformed cells, PI3K, MAPKAPK2, Akt, cyclin D1 and cyclin D3 in the Akt pathway; IQGAP-2, RabGTPase, Rap1GAP, RasGAP, R-Ras, Krev-1 and TC21 of the Ras GTP/GDP protein family; and A-Raf, B-Raf and PAK in the Ras/MAPK pathway were all markedly upregulated. However, in positive control cells, dimethylhydrazine-transformed cells, only the Akt pathway was activated by PI3K, and no evidence of alteration of any molecules of the Ras superfamily was observed. Inhibition of Akt, p38 and JNK activation led to a reduced proliferation of microcystin-transformed cells. This implies that the constitutive activation of Akt and the p38, JNK of MAPK pathways in microcystin-transformed cells may be the mechanism by which this important external factor acts in the carcinogenesis of CRC.