sulprostone and Liver-Neoplasms

A wide range of studies has demonstrated the potent anticancer activity of Chinese herbs. Here, we evaluated the anticancer activity and molecular mechanisms of Actinidia chinensis root extract (acRoots) on hepatocellular carcinoma (HCC). HepG2 HCC cells were treated with various concentrations of acRoots for 72 h and examined by mRNA expression profiling, revealing alterations in cellular immunity, inflammation, proliferation, cell cycle, and metabolic signaling responses. Further analysis of the altered genes in cellular immunity and inflammation gene clusters identified prostaglandin E receptor 3 (EP3) as a key regulator of gene expression in response to acRoots. Further analysis revealed inhibition of cell growth, migration, and invasion in HCC in response to acRoots, along with increased apoptosis due to downregulation of EP3 expression. Treatment with acRoots and EP3 antagonist L-798106 led to decreases in VEGF, EGFR, MMP2, and MMP9 expression in HCC cells, along with significant effects on growth, migration, invasion, and apoptosis; the effects were reversed/blocked by the EP3 agonist sulprostone. Taken together, these data clearly demonstrated that acRoots inhibit HCC cell invasion and metastasis via inhibition of EP3 expression, resulting in decreased activation of VEGF, EGFR, MMP2, and MMP9.

Topics: Actinidia; Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dinoprostone; Disease Progression; Gene Expression Regulation, Neoplastic; Humans; Inflammation; Liver Neoplasms; Neoplasm Invasiveness; Neoplasm Proteins; Phytotherapy; Plant Extracts; Plant Roots; Receptors, Prostaglandin E, EP3 Subtype; Signal Transduction; Sulfonamides

Liver cancer is a common human cancer with a high mortality rate and currently there is no effective chemoprevention or systematic treatment. Recent evidence suggests that prostaglandin E(2) (PGE(2)) plays an important role in the occurrence and development of liver cancer. However, the mechanisms through which PGE(2) promotes liver cancer cell growth are not yet fully understood. It has been reported that the increased expression of FUSE-binding protein 1 (FBP1) significantly induces the proliferation of liver cancer cells. In this study, we report that PGE(2) promotes liver cancer cell growth by the upregulation of FBP1 protein expression. Treatment with PGE2 and the E prostanoid 3 (EP3) receptor agonist, sulprostone, resulted in the time-dependent increase in FBP1 protein expression; sulprostone increased the viability of the liver cancer cells. The protein kinase A (PKA) inhibitor, H89, and the adenylate cyclase (AC) inhibitor, SQ22536, inhibited the cell viability accelerated by sulprostone. By contrast, the Gi subunit inhibitor, pertussis toxin (PTX), exhibited no significant effect. Treatment with PGE(2) and sulprostone caused a decrease in JTV1 protein expression, blocked the binding of JTV1 with FBP1, which served as a mechanism for FBP1 degradation, leading to the decreased ubiquitination of FBP1 and the increase in FBP1 protein expression. Furthermore, H89 and SQ22536 prevented the above effects of JTV1 and FBP1 induced by PGE(2) and sulprostone. These findings indicate that the EP3 receptor activated by PGE(2) may couple to Gs protein and activate cyclic AMP (cAMP)-PKA, downregulating the levels of JTV1 protein, consequently inhibiting the ubiquitination of FBP1 and increasing FBP1 protein expression, thus promoting liver cancer cell growth. These observations provide new insights into the mechanisms through which PGE(2) promotes cancer cell growth.

Topics: Abortifacient Agents, Nonsteroidal; Adenine; Adenylyl Cyclase Inhibitors; Carrier Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colforsin; Cyclic AMP; Dinoprostone; DNA Helicases; DNA-Binding Proteins; Enzyme Activation; Enzyme Inhibitors; Humans; Isoquinolines; Liver Neoplasms; Nuclear Proteins; Pertussis Toxin; Phosphorylation; Protein Kinase Inhibitors; Receptors, Prostaglandin E, EP3 Subtype; Receptors, Prostaglandin E, EP4 Subtype; RNA Interference; RNA-Binding Proteins; RNA, Small Interfering; Smad2 Protein; Sulfonamides; Ubiquitination