The impact of TGF-β1 on the mRNA expression of TβR I, TβR II, Smad4 and the invasiveness of the JEG-3 placental choriocarcinoma cell line

Guhong Injection Protects Against Apoptosis in Cerebral Ischemia by Maintaining Cerebral Microvasculature and Mitochondrial Integrity Through the PI3K/AKT Pathway

Guhong injection (GHI) can be used for the treatment of ischemic stroke. We investigated the antiapoptotic activity of GHI, its ability to repair the cerebral microvessels and mitochondria, and the PI3K/AKT signaling pathway of GHI against cerebral ischemia. Western blot and immunohistochemical analyses were used to determine the expression of cleaved caspase-3, B-cell lymphoma-2 (Bcl-2), cytochrome c (Cyt-c), basic fibroblast growth factor (BFGF), vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), and proteins in the PI3K/AKT signaling pathway. Transmission electron microscopy and scanning electron microscopy were used to evaluate the structures of the cerebral microvasculature and cells. Hoechst 33342 staining was used to evaluate the nuclear morphology. FITC-AV/PI double staining was used to measure the antiapoptotic effects. The fluorescent dye JC-1 was used to measure mitochondrial membrane potential. The enzyme-linked immunosorbent assay (ELISA) was used to detect the activities of matrix metalloproteinase-9 (MMP-9). Biochemical assay kits were used to detect the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA). Compared with the middle cerebral artery occlusion (MCAO) group, there was decreased infarct volume and significantly improved neurological deficits in the GHI group. In addition, the expression of Bcl-2 was significantly upregulated, while the expression of Cyt-c, Bax, and cleaved caspase-3 was notably downregulated. GHI administration attenuated the pathological change and morphology of the cerebral microvasculature, and immunohistochemical staining indicated that the expressions of BFGF, VEGF, and TGF-β1 were significantly increased. The cell morphology, cell viability, cell nuclei characteristics, and mitochondrial morphology normalized following GHI treatment, which decreased the release of Cyt-c and the mitochondrial membrane potential. The levels of LDH, MMP-9, and MDA decreased, while SOD increased. Moreover, GHI administration inhibited the activation of the PI3K/AKT signaling pathway in rat brain microvascular endothelial cells (rBMECs) following oxygen/glucose deprivation (OGD) injury. Therefore, our results show that GHI administration resulted in antiapoptosis of cerebral cells and repair of cerebral microvessels and mitochondria via the PI3K/AKT signaling pathway.

miR-373-3p inhibits epithelial-mesenchymal transition via regulation of TGFβR2 in choriocarcinoma

AIM

Previous studies have indicated that early metastasis is a major cause of mortality in patients with choriocarcinoma. However, what determines whether early metastasis of choriocarcinoma has occurred is unknown. The emerging role of miRNA in regulating cancer development and progression has been recognized. miR-373 has been shown to play pivotal roles in tumorigenesis and metastasis. However, whether miR-373 functions to promote choriocarcinoma metastasis is not clear. The purpose of this study is to determine the function of miR-373-3p in the progression of this cancer.

METHODS

In this study, we first compared epithelial-mesenchymal transition (EMT)-related markers, which were inversely correlated with miR-373-3p expression in trophoblast and choriocarcinoma cell lines. Using PCR and Western blot, upregulation of miR-373-3p was observed to inhibit EMT progression. Similarly, gain- and loss-of-function studies revealed that ectopic miR-373-3p overexpression inhibited the migration by transwell methods of choriocarcinoma cells.

RESULTS

Our results revealed that miR-373-3p acted as an EMT inhibitor in JEG-3 and JAR cells; this was due to its mediation of the transforming growth factor-β (TGFβ) signaling pathway, which was responsible for EMT. miRNA microarray analysis demonstrated that miR-373-3p interacted with the 3' untranslated region of TGFβR2 mRNA, and then Western blot and dual-luciferase reporter gene assays verified this interaction.

CONCLUSION

Our findings suggest that miR-373-3p upregulation partly accounts for TGFβR2 downregulation and leads to a restraint of EMT and migration. miR-373-3p may therefore serve as a valuable potential target in the treatment of choriocarcinoma.

PFOS-induced placental cell growth inhibition is partially mediated by lncRNA H19 through interacting with miR-19a and miR-19b

Perfluorooctane sulfonic acid (PFOS), a persistent environmental pollutant, has been associated with decreased birth weight. The dysregulation of long non-coding RNA (lncRNA) H19 has been implicated in pregnancy complications such as intra-uterine growth retardation (IUGR), preeclampsia (PE), however, the expression and function of H19 in PFOS-exerted detrimental effects in the placenta remains to be unveiled. Here, we explored the role of H19 in PFOS-induced placental toxicity. Results showed that PFOS caused decreased cell growth in human HTR-8/SVneo cells. Expression of H19 was increased, while miR-19a and miR-19b expression were decreased in mice placenta tissues and in HTR-8/SVneo cells exposed to PFOS. A significant hypomethylation was observed at the H19 promoter in the placentas of mice that were gestational exposed to high dose of PFOS. H19 was confirmed to bind with miR-19a and miR-19b, targeting SMAD4. Furthermore, H19 appeared to partially improve the cell growth of HTR-8/SVneo cells exposed to PFOS via upregulation of miR-19a and miR-19b. In summary, our findings revealed that H19/miR-19a and miR-19b/SMAD4 axis exerted important functions in PFOS-induced placenta cell toxicity.

MST4 Regulates Epithelial-Mesenchymal Transition of Choriocarcinoma by Mediating TGF-β1 Expression

Background

Mammalian Ste20-like kinase 4 (MST4), also known as serine/threonine kinase 26 (STK26), promotes development of several cancers and is found to be highly expressed in the placenta. However, in choriocarcinoma that originated from the placenta, the expression of MST4 was undetermined and its mechanism was unknown. In this study, the expression of MST4 in choriocarcinoma as well as the underlying mechanism was explored.

Purpose

To detect the expression of MST4 in patient samples and mechanism of mediating EMT by MST4 in choriocarcinoma.

Patients and Methods

The metastatic lesions of choriocarcinoma (n=17) and volunteer villus (n=17) were collected to determine MST4 expression using immunohistochemistry and H&E staining. We use siRNA and lentiviral vector to knockdown MST4 and use plasmid to overexpress MST4 in choriocarcinoma. Then, we apply real-time polymerase chain reaction (RT-PCR), Western blot assay and immunofluorescence assay to detect target protein expressions. Cell invasion and migration and cell proliferation were detected by transwell assay and wound healing assay and CCK-8 and cell colony formation.

Results

MST4 is lowly expressed in the metastatic lesions of choriocarcinoma patients when compared with normal villus. Knockdown of MST4 activated epithelial–mesenchymal transition (EMT) process, significantly increasing the ability of invasion and migration in choriocarcinoma cell lines (JAR and JEG-3). In contrast, the EMT process was restrained in choriocarcinoma cell lines with overexpressed MST4. Meanwhile, genome-wide gene expression array, Western blot and ELISA revealed that tumor growth factor-beta 1 (TGF-β1) has significantly increased. The EMT process and metastatic prompting biofunction were reversed after using TGF-β1 inhibitor (LY364947) in the choriocarcinoma cell lines with MST4 knockdown.

Conclusion

Our studies demonstrated that MST4 was lowly expressed in patient samples. Additionally, JAR and JEG-3 increase cell invasion and migration ability while there is no influence on cell proliferation with MST4 knockdown. Conversely, the metastatic ability of JAR and JEG-3 was decreased with overexpressed MST4. Moreover, TGF-β1 was a key factor after MST4 knockdown. In conclusion, MST4 affects choriocarcinoma EMT by mediating TGF-β1 expression.

Inhibitory effect of dihydromyricetin on the proliferation of JAR cells and its mechanism of action

Dihydromyricetin (DMY) is a novel natural drug with antitumor activity against some cancer cells without obvious toxicity. Previously, its apoptotic effect on human choriocarcinoma was detected. The present study further investigated the therapeutic potential of DMY as a new drug for the treatment of choriocarcinoma, as well as its anti-proliferative effect and mechanism of action. The short-term proliferation of JAR cells was determined by MTT assay, whereas the effect of DMY on long-term cell proliferation was determined by colony forming assay. Flow cytometry was used to detect changes in the cell cycle. Furthermore, western blotting was used to detect the expression levels of proliferation-associated proteins such as cyclin A1, cyclin D1, SMAD3 and SMAD4. Reverse transcription-quantitative PCR (RT-qPCR) was used to quantify mRNA expression levels. The results indicated that DMY inhibited short and long-term proliferation of JAR cells in a concentration-dependent manner. Flow cytometry demonstrated S/G₂/M cell cycle arrest, and western blotting revealed the downregulation of SMAD3, SMAD4, cyclin A1 and cyclin D1 expression levels. The results of RT-qPCR and western blotting were consistent. Overall, the findings of the present study suggest that DMY inhibits the proliferation of human choriocarcinoma JAR cells, potentially through cell cycle arrest via the downregulation of cyclin A1, cyclin D1, SMAD3 and SMAD4 expression levels.

Transforming growth factor β1 promotes invasion of human JEG-3 trophoblast cells via TGF-β/Smad3 signaling pathway

Transforming growth factor (TGF)-β1 is involved invasion of human trophoblasts. However, the underlying mechanisms remain unclear. In this study, we performed Transwell assay and found that TGF-β1 promoted the invasion of trophoblast cell line JEG-3. Treatment with TGF-β1 up-regulated the expression of receptor-regulated Smad transcription factors Smad2 and Smad3, and two invasive-associated genes, namely, matrix metallopeptidase (MMP)-9 and MMP-2, in JEG-3 cells. Over-expressing activin receptor-like kinase (ALK) 5, the TGF-β type I receptor (TβRI) enhanced the up-regulation of Smad2, Smad3, MMP-9, and MMP-2 induced by TGF-β1, whereas application of TβRI inhibitor SB431542 diminished the stimulatory effects of TGF-β1 on these genes. Furthermore, transfection of Smad3 and ALK-5 seperately or in combination into JEG-3 cells before TGF-β1 treatment significantly increased the expression of MMP-9 and MMP-2. By contrast, silencing Smad3 and Smad2 by siRNAs significantly decreased the expression of MMP-9 and MMP-2, with Smad3 silence having a more potent inhibitory effect. Inhibiting TβRI with SB431542 or knockdown of Smad3, but not Smad2, abolished the stimulatory effect of TGF-β1 on the invasion of JEG-3 cells. Taken together, the results indicate that TGF-β1 activates the Smads signaling pathway in JEG-3 trophoblast cells and Smad3 play a key role in TGF-β1-induced invasion of JEG-3 and up-regulation of MMP-9 and MMP-2 expression.

The role, mechanism and potentially novel biomarker of microRNA-17-92 cluster in macrosomia

Macrosomia is one of the most common perinatal complications of pregnancy and has life-long health implications for the infant. microRNAs (miRNAs) have been identified to regulate placental development, yet the role of miRNAs in macrosomia remains poorly understood. Here we investigated the role of miR-17-92 cluster in macrosomia. The expression levels of five miRNAs in miR-17-92 cluster were significantly elevated in placentas of macrosomia, which may due to the up-regulation of miRNA-processing enzyme Drosha and Dicer. Cell cycle pathway was identified to be the most relevant pathways regulated by miR-17-92 cluster miRNAs. Importantly, miR-17-92 cluster increased proliferation, attenuated cell apoptosis and accelerated cells entering S phase by targeting SMAD4 and RB1 in HTR8/SVneo cells. Furthermore, we found that expression of miR-17-92 cluster in serum had a high diagnostic sensitivity and specificity for macrosomia (AUC: 80.53%; sensitivity: 82.61%; specificity: 69.57%). Our results suggested that miR-17-92 cluster contribute to macrosomia development by targeting regulators of cell cycle pathway. Our findings not only provide a novel insight into the molecular mechanisms of macrosomia, but also the clinical value of miR-17-92 cluster as a predictive biomarker for macrosomia.

Carcinosarcoma with Choriocarcinomatous and Osteosarcomatous Differentiation in a Patient with Juvenile Polyposis Syndrome

Juvenile polyposis syndrome (JPS) is an infrequent autosomal dominant hereditary predisposition to the occurrence of hamartomatous polyps in the colon and rectum. We describe the case of a 12-year-old boy with JPS associated with an abdominal tumor. Histological sections of the abdominal tumor showed components of adenocarcinoma, osteosarcoma, and choriocarcinoma. Immunohistochemistry was AE1/AE3, CK7, HCG and SALL4 positive. Juvenile polyposis syndrome patients are at increased risk of colorectal adenocarcinoma. However, we present a case of an adenocarcinoma associated with other unusual components. This association has not been reported before.

Icotinib inhibits the invasion of Tca8113 cells via downregulation of nuclear factor κB-mediated matrix metalloproteinase expression

Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor, which has been revealed to inhibit proliferation in tumor cells. However, the effect of icotinib on cancer cell metastasis remains to be explained. This study examines the effect of icotinib on the migration and invasion of squamous cells of tongue carcinoma (Tca8113 cells) in vitro. The results of the Boyden chamber invasion assay demonstrated that icotinib reduced cell invasion, suppressed the protein levels of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and increased the expression of tissue inhibitor of metalloproteinase-1. In addition, icotinib was found to significantly decrease the protein levels of nuclear factor κB (NF-κB) p65, which suggested that icotinib inhibits NF-κB activity. Furthermore, treatment with the NF-κB inhibitor, pyrrolidine dithiocarbamate, suppressed cell invasion and MMP-2 expression. These results suggested that icotinib inhibits the invasion of Tca8113 cells by downregulating MMP via the inactivation of the NF-κB signaling pathways.

Suppression of choriocarcinoma invasion and metastasis following blockade of BDNF/TrkB signaling

Brain-derived neurotrophic factor (BDNF) acts through its cognate receptor tyrosine kinase-B (TrkB) to regulate diverse physiological functions in reproductive and other tissues. In normal and malignant trophoblastic cells, the BDNF/TrkB signaling promotes cell growth. Due to the highly malignant nature of choriocarcinoma, we investigated possible involvement of this system in choriocarcinoma cell invasion and metastasis. We demonstrated that treatment of cultured choriocarcinoma cells, known to express both BDNF and TrkB, with a soluble TrkB ectodomain or a Trk receptor inhibitor K252a suppressed cell invasion accompanied with decreased expression of matrix metalloproteinase-2, a cell invasion marker. In vivo studies using a tumor xenograft model in athymic nude mice further showed inhibition of cell invasion from tumors to surrounding tissues following the suppression of endogenous TrkB signaling. For an in vivo model of choriocarcinoma metastasis, we performed intravenous injections of JAR cells expressing firefly luciferase into severe combined immunodeficiency (SCID) mice. Treatment with K252a inhibited metastasis of tumors to distant organs. In vivo K252a treatment also suppressed metastatic tumor growth as reflected by decreased cell proliferation and increased apoptosis and caspases-3/7 activities, together with reduced tissue levels of a tumor marker, human chorionic gonadotropin-β. In vivo suppression of TrkB signaling also led to decreased expression of angiogenic markers in metastatic tumor, including cluster of differentiation 31 and vascular endothelial growth factor A. Our findings suggested essential autocrine/paracrine roles of the BDNF/TrkB signaling system in choriocarcinoma invasion and metastasis. Inhibition of this signaling could serve as the basis to develop a novel therapy for patients with choriocarcinoma.

Crosstalk between p38 and Smad3 through TGF-β1 in JEG-3 choriocarcinoma cells

Choriocarcinoma is a highly malignant trophoblastic tumor related to pregnancy that often occurs with a complete hydatidiform mole. It grows quickly and can also widely metastasize to other organs or tissues through both the venous and lymphatic systems. The transforming growth factor-β1 (TGF-β1) belongs to a growth factor superfamily and has been suggested to play a critical role in regulating the genesis and development of choriocarcinoma through a variety of Smad-independent pathways, including the p38 MAPK pathway. Previous studies indicated that TGF-β can activate the p38 MAPK pathway. In this study, we investigated Smad and p38 MAPK signaling in JEG-3 choriocarcinoma cells using p38 MAPK inhibitor and TGF-β receptor inhibitor. Immunofluorescence and western blot assays were used to detect the proteins in Smad and p38 MAPK pathways. Our data demonstrated that TGF-β can activate Smad3 and induce Smad3 translocation into the nucleus in JEG-3 cells. Blockade of the TGF-β pathway significantly reduced the expression levels of p38 and phospho-p38. p38 MAPK inhibitors (SB 203580) can attenuate TGF-β1-induced Smad3 expression and suppress the activation of smad3. These findings indicate crosstalk between p38 and smad3 through TGF-β1 in choriocarcinoma cells.