Inhibitory Effects of Quercetin on Progression of Human Choriocarcinoma Cells Are Mediated Through PI3K/AKT and MAPK Signal Transduction Cascades.

As a major dietary flavonol, quercetin mitigates proliferation and progression of cancer due to its anti-angiogenic, anti-inflammatory, anti-oxidant, and apoptotic biological effects on cells. Although its apoptotic effects have been reported for various cancers, little is known of the functional role of quercetin in gestational choriocarcinoma. Results of the present study indicated that quercetin reduced proliferation and induced cell death in two choriocarcinoma cell lines, JAR and JEG3 cells, with an increase in the sub-G1 phase of the cell cycle. In addition, quercetin induced mitochondrial dysfunction significantly reduced mitochondrial membrane potential (MMP) and increased production of reactive oxygen species (ROS) in both JAR and JEG3 cells. Further, quercetin inhibited phosphorylation of AKT, P70S6K and S6 proteins whereas, it increased phosphorylation of ERK1/2, P38, JNK and P90RSK proteins in JAR and JEG3 cells. The decrease in viability of choriocarcinoma cells treated with quercetin was confirmed by using combinations of quercetin and pharmacological inhibitors of the PI3K and MAPK signaling pathways. Classical chemotherapeutic agents, cisplatin (a platinum-based drug) and paclitaxel (a taxene-based drug), inhibited proliferation of JAR and JEG3 cells, and when combined with quercetin, the antiproliferative effects of cisplatin and paclitaxel were enhanced for both choriocarcinoma cell lines. Collectively, these results suggest that quercetin prevents development of choriocarcinoma and may be a valuable therapeutic agent for treatment of choriocarcinoma through its regulation of PI3K and MAPK signal transduction pathways. J. Cell. Physiol. 232: 1428-1440, 2017. © 2016 Wiley Periodicals, Inc.

Lim W ，Yang C ，Park S ，Bazer FW ，Song G ... -  《-》

Chrysophanol Induces Apoptosis of Choriocarcinoma Through Regulation of ROS and the AKT and ERK1/2 Pathways.

Chrysophanol is an anthraquinone compound, mainly isolated from rhubarb, with anti-cancer effects on some types of cancer cells. However, effects of chrysophanol on human choriocarcinoma cells are not known. Therefore, the objective of this study was to determine effects of chrysophanol on choriocarcinoma cells (JAR and JEG-3) and identify signal transduction cascades activated by chrysophanol. Results of present study, showed that chrysophanol decreased cell viability and induced apoptosis of JEG-3, but not JAR cells, in a dose-dependent manner. Chrysophanol also increased oxidative stress in JEG-3 cells by inducing ROS generation followed by mitochondrial dysfunction including depolarization of mitochondrial inner membrane potential. Western blot analysis revealed that ERK1/2, P90RSK, AKT, and P70S6K were increased significantly in JEG-3 cells by chrysophanol. Next, we investigated chrysophanol-mediated effects on proliferation of JEG-3 cells using pharmacological inhibitors of PI3K/AKT (LY294002) and ERK1/2 (U0126). Inhibition of AKT and ERK1/2 prevented chrysophanol-induced stimulation of proliferation of JEG-3 cells. In addition, the phosphorylation of AKT and ERK1/2 was suppressed by LY294002 and U0126 in JEG-3 cells treated with chrysophanol, whereas, the AKT protein was activated by pre-treatment of JEG-3 cells with U0126. Furthermore, we compared therapeutic effects of chrysophanol with cisplatin and paclitaxel which are conventional salvage regimens for choriocarcinoma. Our results verified that chrysophanol has synergistic effects with traditional therapy to increase apoptosis of JEG-3 cells. Collectively, these results indicate that chrysophanol is a potential effective chometherapeutic agent for treatment of choriocarcinoma therapy, and minimizing side effects of conventional treatment regimens. J. Cell. Physiol. 232: 331-339, 2017. © 2016 Wiley Periodicals, Inc.

Lim W ，Yang C ，Bazer FW ，Song G ... -  《-》

Apigenin Reduces Survival of Choriocarcinoma Cells by Inducing Apoptosis via the PI3K/AKT and ERK1/2 MAPK Pathways.

Apigenin is a flavonoid found in parsley, onions, oranges, tea, chamomile, wheat, and sprouts. It has a variety of biological properties including anti-oxidant, anti-mutagenic, anti-carcinogenic, anti-inflammatory, anti-proliferative, and anti-spasmodic effects. Based on epidemiological and case-control studies, apigenin is regarded as a novel chemotherapeutic agent against various cancer types. However, little is known about the effects of apigenin on choriocarcinoma cells. Therefore, we investigated the anti-cancer effects of apigenin on choriocarcinoma cells (JAR and JEG3) in the present study. Apigenin reduced viability and migratory properties, increased apoptosis, and suppressed mitochondrial membrane potential in both the JAR and JEG3 cells. In addition, apigenin predominantly decreased phosphorylation of AKT, P70RSK, and S6 whereas the phosphorylation of ERK1/2 and P90RSK was increased by apigenin treatment of JAR and JEG3 cells in a dose-dependent manner. Moreover, treatment of JAR and JEG3 cells with both apigenin and pharmacological inhibitors of PI3K/AKT (LY294002) and ERK1/2 (U0126) revealed synergistic anti-proliferative effects. Collectively, these results indicated that the apigenin is an invaluable chemopreventive agent that inhibits progression and metastasis of choriocarcinoma cells through regulation of PI3K/AKT and ERK1/2 MAPK signal transduction mechanism. J. Cell. Physiol. 231: 2690-2699, 2016. © 2016 Wiley Periodicals, Inc.

Lim W ，Park S ，Bazer FW ，Song G ... -  《-》

Naringenin suppresses growth of human placental choriocarcinoma via reactive oxygen species-mediated P38 and JNK MAPK pathways.

Human placental choriocarcinoma is a gestational trophoblastic tumor with high rates of metastasis and reoccurrence. However, some patients with choriocarcinoma are chemoresistance to conventional chemotherapeutic agents. Naringenin increases apoptosis in human placental choriocarcinoma cells. We investigated the effects of naringenin on proliferation and migration of JAR and JEG3 cells, and performed TUNEL and Annexin V/PI staining assays to examine apoptotic effects of naringenin on both cells. In addition, we studied the loss of mitochondrial membrane potential (MMP) and the production of mitochondrial reactive oxygen species (ROS) to determine the specific reason for apoptosis of choriocarcinoma cells being mediated via mitochondria. Consistent with the induction of production of ROS by naringenin in both choriocarcinoma cell lines, we investigated lipid peroxidation and glutathione levels in both JAR and JEG3 cells since both are affected by ROS. We next determined dose-dependent effects of naringenin and its pharmacological inhibitors on signal transduction pathways in JAR and JEG3 cells by western blot analyses. Naringenin reduced viability and migratory functions of both cell lines, and increased mitochondria related apoptosis induced by ROS and lipid peroxidation, decreased glutathione and decreased mitochondrial membrane potential MMP in a dose-dependent manner. We also determined naringenin activated phosphorylation of ERK1/2, P38, JNK and P70S6K in JAR and JEG3 cells in a dose-response manner. Although naringenin induced phosphorylation of AKT proteins in JAR cells, it suppressed phosphorylation of the protein in JEG3 cells. In addition, we confirmed the mechanism of naringenin-induced cell signaling by using a combination of naringenin and pharmacological inhibitors of the PI3K and MAPK pathways, as well as a ROS inhibitor in JAR and JEG3 cell lines. Collectively, results of this study indicate that naringenin is a potential therapeutic molecule with anti-cancer effects on choriocarcinoma cells by inducing generation of ROS and activation of the MAPK pathways.

Park S ，Lim W ，Bazer FW ，Song G ... -  《-》

Luteolin Inhibits Proliferation and Induces Apoptosis of Human Placental Choriocarcinoma Cells by Blocking the PI3K/AKT Pathway and Regulating Sterol Regulatory Element Binding Protein Activity.

Luteolin is a natural compound known for its anticancer effects on various human cancers by regulating signal transduction cascades. However, the effects of luteolin on human placental choriocarcinoma are not known. Results of the present study revealed that luteolin decreased viability of JAR and JEG-3 cells, which are valuable placental models, in a dose-dependent manner, and it induced apoptosis and loss of mitochondrial membrane potential in JAR and JEG-3 cells. The results also suggested that the PI3K/AKT pathway was inhibited by luteolin treatment of JAR and JEG-3 cells in a dose- and time-dependent manner. Next, we established effects of luteolin in the presence of pharmacological inhibitors of PI3K/AKT, ERK1/2 MAPK, and mTOR on proliferation of JAR and JEG-3 cells. In addition, these inhibitors were used to verify phosphorylation of AKT, GSK3beta, and ERK1/2 and to confirm mechanisms regulated by luteolin in JAR and JEG-3 cells. We also determined levels of SREBP1 and SREBP2 expression to investigate regulatory functions of luteolin in lipid metabolism in JAR and JEG-3 cells. Expression levels of both SREBP1 and SREBP2 mRNAs were significantly reduced, but only SREBP1 protein was influenced by luteolin. We compared viability of JAR and JEG-3 cells in response to luteolin alone or in combination with other chemotherapeutic drugs (etoposide, cisplatin, and paclitaxel) and found that luteolin has synergistic effects with the conventional chemotherapeutic drugs as an anticancer agent. Collectively, these results showed that luteolin plays an important role in the treatment of human choriocarcinoma cells by inhibiting the PI3K/AKT/mTOR/SREBP cascade and expression of lipogenic genes.

Lim W ，Yang C ，Bazer FW ，Song G ... -  《-》