Placental choriocarcinoma is a malignant trophoblastic tumor associated with placentation. During placentation, complicated molecular networks are mediated by endocrine and paracrine signals. Serotonin neurotransmitters have been identified in the transmembrane region of human placental choriocarcinoma (HPC) cells as tumor promoters; therefore, their antagonists have anti-cancer properties. Although methiothepin, a serotonin receptor antagonist and FDA-approved psychotropic agent, has shown multi-pharmacological functions in various disease models, its anti-tumorigenic activity and mechanisms underlying its action against HPC are unknown. Therefore, we identified the anti-cancer effects of methiothepin in JEG3 and JAR HPC cells. Methiothepin attenuated mitochondrial function and induced endoplasmic reticular stress, reducing oxidative phosphorylation and causing metabolic shifting in HPC cells. Furthermore, methiothepin showed synergistic pharmacological effects with paclitaxel in HPC cells. Our results highlight the robust tumor-suppressive function of methiothepin in HPC. Our findings provide new insights into the repositioning of methiothepin from a psychotropic agent to novel anti-cancer agents, especially against HPC.
Jin-Young Lee, Whasun Lim, and Gwonhwa Song
Gwonhwa Song, Fuller W Bazer, and Thomas E Spencer
Radical S-adenosyl methionine domain containing 2 (RSAD2) encodes a cytoplasmic antiviral protein induced by interferons (IFN). Interferon-induced with helicase C domain 1 (IFIH1) is a RNA helicase involved in innate immune defense against viruses, growth suppression, and apoptosis. Interferon tau (IFNT), a Type I IFN produced by the peri-implantation ruminant conceptus, acts on the uterine endometrium to signal pregnancy recognition and promote receptivity to implantation. Transcriptional profiling identified RSAD2 and IFIH1 as IFNT regulated genes in the ovine uterine endometrium. This study tested the hypothesis that RSAD2 and IFIH1 were induced in the endometrium in a cell type-specific manner by IFNT from the conceptus during early pregnancy. Endometrial RSAD2 and IFIH1 mRNA increased between days 12 and 16 of pregnancy, but not of the estrous cycle. In pregnant ewes, RSAD2 and IFIH1 mRNAs increased in endometrial glands, and stroma and immune cells, but not in the luminal epithelium. Neither gene was expressed in the trophectoderm of day 18 or 20 conceptuses. Progesterone (P4) treatment of ovariectomized ewes did not induce expression RSAD2 or IFIH1 mRNA in the endometrium; however, intrauterine injections of IFNT induced expression of RSAD2 and IFIH1 mRNA in endometria of ewes treated with P4, as well as in ewes treated with P4 and the progesterone receptor antagonist, ZK 136,317. These results indicate that conceptus IFNT induces both RSAD2 and IFIH1 in a P4-independent manner in the ovine uterine endometrium. These two IFNT-stimulated genes are proposed to have biological roles in the establishment of uterine receptivity to the conceptus during implantation through induction of an antiviral state and modulation of local immune cells in the endometrium.
Changwon Yang, Gwonhwa Song, and Whasun Lim
In humans, pregnancy maintenance depends on normal placental formation following trophoblast invasion into the endometrium and vascular remodeling. In the early stages of pregnancy, immune tolerance, inflammatory response and adaptation to hypoxia need to be precisely regulated in the placental microenvironment. Various types of cells, such as trophoblasts, endothelial cells, immune cells, mesenchymal stem cells (MSCs) and adipocytes, induce normal placental development via intercellular interactions through soluble factors. Extracellular vesicles (EVs) are used to diagnose various diseases because their constituents vary depending on the type of cell of origin and pathological characteristics. EV-derived microRNAs (miRNAs) and proteins in the placenta regulate inflammatory responses and the invasion of trophoblasts through intercellular delivery in the placental microenvironment. If the placenta does not adapt to the changed environment during early pregnancy, pregnancy disorders such as pre-eclampsia, preterm birth and gestational diabetes mellitus can occur. Thus, the important roles of EVs during pregnancy and development is fast emerging. This review describes the physiological role of EVs during placentation and their composition in the human placenta. It also suggests the possibility of finding EV markers that can diagnose pregnancy disorders. Furthermore, it describes the properties of EVs that affect pregnancy in livestock.
Gwonhwa Song, M Carey Satterfield, Jinyoung Kim, Fuller W Bazer, and Thomas E Spencer
The actions of leukemia inhibitory factor (LIF) via LIF receptor (LIFR) and its co-receptor, IL6 signal transducer (IL6ST), are implicated in uterine receptivity to conceptus implantation in a number of species including sheep. The present study determined the effects of the estrous cycle, pregnancy, progesterone (P4), and interferon tau (IFNT) on the expression of LIFR and IL6ST in the ovine uterus. LIFR mRNA and protein were localized to the endometrial luminal (LE) and superficial glandular epithelia (sGE), whereas IL6ST mRNA and protein were localized primarily in the middle to deep GE. Both LIFR and IL6ST mRNAs and protein were more abundant in pregnant than cyclic ewes and increased from days 10 to 20 of pregnancy. Treatment of ovariectomized ewes with P4 and/or infusion of ovine IFNT increased LIFR and IL6ST in endometrial LE/sGE and GE respectively. Co-expression of LIFR and IL6ST as well as phosphorylated STAT3 was observed only in the upper GE of the endometrium as well as in the conceptus trophectoderm on days 18 and 20. In mononuclear trophectoderm and GE cells, LIF elicited an increase in phosphorylated STAT3 and MAPK3/1 MAPK proteins. Collectively, these results suggest that LIFR and IL6ST are both stimulated by IFNT and regulated by P4 in a complex stage- and cell-specific manner, and support the hypothesis that LIF exerts effects on the endometrial GE as well as conceptus trophectoderm during early pregnancy in sheep. Thus, LIF and STAT3 may have biological roles in endometrial function and trophectoderm growth and differentiation.
Gwonhwa Song, Jo-Ann G W Fleming, Jinyoung Kim, Thomas E Spencer, and Fuller W Bazer
Interferon τ (IFNT), the pregnancy recognition signal in ruminants, abrogates the luteolytic mechanism for maintenance of the corpus luteum for production of progesterone (P4). This study examined the expression of DEAD (Asp-Glu-Ala-Asp) box polypeptide 58 (DDX58) and phospholipid scramblase 1 (PLSCR1) mRNAs in the ovine uterus as these genes were increased most in 2fTGH (STAT1 positive) cells by IFNT. The results of this study indicated that IFNT regulates expression of DDX58 and PLSCR1 mRNAs in the ovine uterus, which confirmed the results of the in vitro transcriptional profiling experiment with the 2fTGH (parental STAT1 positive) and U3A (STAT1 null) cell lines. Steady-state levels of DDX58 and PLSCR1 mRNAs increased in cells of the ovine uterus between days 12 and 20 of pregnancy, but not between days 10 and 16 of the estrous cycle. The expression of DDX58 and PLSCR1 mRNAs was greatest in endometrial stromal cells, but there was transient expression in uterine luminal and superficial glandular epithelial cells. P4 alone did not induce expression of DDX58 and PLSCR1 mRNAs; however, intrauterine injections of IFNT did induce expression of DDX58 and PLSCR1 mRNAs in the endometria of nonpregnant ewes independent of effects of P4. These results indicate that IFNT induces expression of DDX58 and PLSCR1 in ovine endometrial cells via the classical STAT1-mediated cell signaling pathway. Based on their known biological effects, DDX58 and PLSCR1 are IFN-stimulated genes, which may increase the antiviral status of cells of the pregnant uterus to protect against viral infection and/or enhance secretion of type I IFNs that inhibit viral replication.
Minkyeong Lee, Changwon Yang, Gwonhwa Song, and Whasun Lim
The reproductive tract in avian females is sensitive to hormonal regulation. Exogenous estrogen induces immature oviduct development to improve egg production after molting. In this process, regressed female reproductive tract is regenerated in response to the secretion of estrogen. However, there is limited knowledge on the physiological mechanisms underlying the regulation of the avian female reproductive system. In our previous study, results from microarray analysis revealed that the expression of genes encoding egg white proteins is affected during molting. Herein, we artificially induced the molting period in chickens through a zinc-containing diet. Subsequently, changes in the expression of genes encoding egg white proteins were confirmed in the oviduct tissue. The levels of MUC5B, ORM1, RTBDN, and TENP mRNA were significantly high in the oviduct, and the genes were repressed in the regression phase, whereas these were expressed in the recrudescence phase, particularly in the luminal epithelium and glandular epithelium of the oviduct, during molting. Moreover, we observed that gene expression was induced in the magnum, the site for the secretion of egg white components. Next, differences in expression levels of the four genes in normal and cancerous ovaries were compared. Collectively, results suggest that the four selected genes are expressed in the female chicken reproductive tract in response to hormonal regulation, and egg white protein-encoding genes may serve as modulators of the reproductive system in hens.
Jin-Young Lee, Jiyeon Ham, Whasun Lim, and Gwonhwa Song
Apomorphine is a derivative of morphine that is used for the treatment of Parkinson’s disease because of its effects on the hypothalamus. Therapeutic effects of apomorphine have also been reported for various neurological diseases and cancers. However, the molecular mechanisms of the antitumor effects of apomorphine are not clear, especially with respect to choriocarcinoma. This is the first study to elucidate the anticancer effects of apomorphine on choriocarcinoma. We found that apomorphine suppressed the viability, proliferation, ATP production, and spheroid formation of JEG3 and JAR choriocarcinoma cells. Moreover, apomorphine activated the intrinsic apoptosis pathway by activating caspases and inhibited the production of anti-apoptotic proteins in choriocarcinoma cells. Further, apomorphine caused depolarization of mitochondria, calcium overload, energy deprivation, and endoplasmic reticulum stress in JEG3 and JAR cells. We confirmed synergistic effects of apomorphine with paclitaxel, a traditional chemotherapeutic agent, and propose that apomorphine could be a potential therapeutic agent in choriocarcinoma and an important candidate for drug repositioning that could help overcome resistance to conventional chemotherapy.
Jin-Young Lee, Hahyun Park, Whasun Lim, and Gwonhwa Song
α,β-Thujone is a natural terpenoid found in many medicinal herbs, such as Artemisia absinthium (wormwood), that exhibits antioxidant, anti-diabetic, and anti-tumorigenic effects. α,β-Thujone has numerous functions; it serves as a food ingredient, cosmetic additive, and medicinal remedy. Although the therapeutic properties of α,β-thujone were previously revealed, a comprehensive description of the mechanisms of its anti-cancer potential in choriocarcinoma is yet to be provided. To our knowledge, this study is the first to demonstrate that α,β-thujone attenuates JEG3 and JAR choriocarcinoma cells through a caspase-dependent intrinsic apoptotic pathway. Moreover, α,β-thujone was demonstrated to induce a global mitochondrial defect and ER stress in choriocarcinoma by causing mitochondrial depolarization, calcium overload, and metabolic alterations, thereby leading to energy deprivation, which eventually contributes to the increase in apoptosis of choriocarcinoma cells. Herein, we also revealed the synergistic anti-cancer activity of α,β-thujone via its sensitization effect on paclitaxel in choriocarcinoma cells. Altogether, our findings suggest that α,β-thujone is a novel, natural pharmacological compound that can be used to treat human placental choriocarcinoma.