Crosstalk between the p38 and TGF-β signaling pathways through TβRI, TβRII and Smad3 expression in plancental choriocarcinoma JEG-3 cells

Stimulus-Induced Activation of the Glycoprotein Hormone α-Subunit Promoter in Human Placental Choriocarcinoma Cells: Major Role of a tandem cAMP Response Element

The glycoprotein hormones LH, FSH, TSH and chorionic gonadotropin consist of a common α-subunit and a hormone-specific β-subunit. The α-subunit is expressed in the pituitary and the placental cells, and its expression is regulated by extracellular signal molecules. Much is known about the regulation of the α-subunit gene in the pituitary, but few studies have addressed the regulation of this gene in trophoblasts. The aim of this study was to characterize the molecular mechanism of stimulus-induced α-subunit gene transcription in JEG-3 cells, a cellular model for human trophoblasts, using chromatin-embedded reporter genes under the control of the α-subunit promoter. The results show that increasing the concentration of the second messengers cAMP or Ca2+, or expressing the catalytic subunit of cAMP-dependent protein kinase in the nucleus activated the α-subunit promoter. Similarly, the stimulation of p38 protein kinase activated the α-subunit promoter, linking α-subunit expression to stress response. The stimulation of a Gαq-coupled designer receptor activated the α-subunit promoter, involving the transcription factor CREB, linking α-subunit expression to hormonal stimulation and an increase in intracellular Ca2+. Deletion mutagenesis underscores the importance of a tandem cAMP response element within the glycoprotein hormone α-subunit promoter, which acts as a point of convergence for a multiple signaling pathway.

Stress signaler p38 mitogen-activated kinase activation: a cause for concern?

Oxidative stress (OS) induced activation of p38 mitogen-activated kinase (MAPK) and cell fate from p38 signaling was tested using the human fetal membrane's amnion epithelial cells (AEC). We created p38 KO AEC using the CRISPR/Cas9 approach and tested cell fate in response to OS on an AEC-free fetal membrane extracellular matrix (ECM). Screening using image CyTOF indicated OS causing epithelial-mesenchymal transition (EMT). Further testing revealed p38 deficiency prevented AEC senescence, EMT, cell migration, and inflammation. To functionally validate in vitro findings, fetal membrane-specific conditional KO (cKO) mice were developed by injecting Cre-recombinase encoded exosomes intra-amniotically into p38αloxP/loxP mice. Amnion membranes from p38 cKO mice had reduced senescence, EMT, and increased anti-inflammatory IL-10 compared with WT animals. Our study suggested that overwhelming activation of p38 in response to OS inducing risk exposures can have an adverse impact on cells, cause cell invasion, inflammation, and ECM degradation detrimental to tissue homeostasis.

Osteogenic growth peptide enhances osteogenic differentiation of human periodontal ligament stem cells

Bone tissue engineering consists of three major components namely cells, scaffolds, and signaling molecules to improve bone regeneration. These integrated principles can be applied in patients suffered from bone resorption diseases, such as osteoporosis and periodontitis. Osteogenic growth peptide (OGP) is a fourteen-amino acid sequence peptide that has the potential to regenerate bone tissues. This study aimed to disseminate the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) with OGP treatment. OGP was elaborated for proliferation, cytotoxicity, osteogenic differentiation effects, and the involvement of osteogenic related signaling pathways in vitro. This study found that OGP at lower concentration shows better effects on cytotoxicity and proliferation. Moreover, OGP at concentration 0.01 nM had the most potential to differentiate hPDLSCs toward osteogenic lineage comparing with higher concentrations of OGP. The phenomenon was mainly involving transforming growth factor-beta (TGF-β), bone morphogenetic protein (BMP), Hedgehog, and Wingless-related (Wnt) pathways. Further, SB-431542 treatment demonstrated the partial involvement of OGP in regulating osteogenic differentiation of hPDLSCs. In conclusion, OGP at low concentration enhances osteogenic differentiation of hPDLSCs by governing TGF-β signaling pathway.

BORIS/CTCFL expression activates the TGFβ signaling cascade and induces Drp1 mediated mitochondrial fission in neuroblastoma

The cancer-testis antigen CTCFL/BORIS (Brother of Regulator of Imprinted Sites) also known, as a paralog of CTCF -the "master weaver of the genome" is a key transcriptional regulator. Both CTCF and BORIS can bind to the same promoter sequence and recruit diverse proteins. BORIS is also known to be associated with actively translating ribosomes suggesting new roles of BORIS in gene expression. Various studies have attempted to elucidate the role of BORIS in different cell types for the development of targeted therapy depending on molecular signatures and genetic aberrations associated with the disease type. The current study is focused on its role in neuroblastoma. Here, we have deciphered the role of BORIS on TGFβ1 pathway which is highly affected by embryonic CTCFL expression. BORIS stabilized the SMAD3 and SMAD4 transcripts leading to prolonged TGFβ activation. Further, loss of BORIS abrogated both the canonical and non-canonical TGFβ signaling suggesting the dependency of TGFβ on BORIS. The effect on the metabolic profile of the neuroblastoma cells were analyzed with change in BORIS expression levels. Also, ectopic expression of BORIS leads to Drp1 phosphorylation (Ser616) enhancing mitochondrial fission followed by a switch in cellular metabolism towards glycolysis. This cellular metabolism switch was in turn supported with a reduction in oxygen consumption rate upon BORIS expression. Interestingly methylome analysis revealed patterns of global histone methylation, a mechanism that regulate important signaling pathways in neuroblastoma. This study analyzes the consequence of BORIS expression in neuroblastoma cells and thereby elucidate its downstream targets, which could help in designing effective therapeutic for treating neuroblastoma. Similar results were obtained in both MYCN amplified and non-MYCN neuroblastoma cell lines, indicating a common mechanism of BORIS/CTCFL action in neuroblastoma.

p38 inhibition enhances TCR-T cell function and antagonizes the immunosuppressive activity of TGF-β

The efficacy of adoptive cell therapy (ACT) relies on the abilities of T cells in self-expansion, survival and the secretion of effector molecules. Here, we presented an optimized method to generate T cells with improved functions by supplementing the culture medium with p38 inhibitor and the combination of IL-7 and IL-15 or IL-2 alone. The addition of p38 inhibitor, Doramapimod or SB202190, to IL-7 and IL-15 culture largely increased the capacity of T cells in the proliferation with enrichment of the naïve-like subsets and expression of CD62L. Importantly, we found this regimen has generated complete T cell resistance to TGF-β-induced functional suppression, with sustained levels of the IFN-γ and Granzyme-B productions. Such findings were also validated in the melanoma-associated antigen recognized by T cells (MART-1) specific T cell receptor (TCR) engineered T cells, which were expanded in Doramapimod and IL-7 + IL-15 added media. In conclusion, we have established and optimized a protocol with the combination of p38 inhibitor, IL-7 and IL-15, rather than IL-2, for the generation of functionally enhanced T cells applicable for ACT.

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.

ChondroGELesis: Hydrogels to harness the chondrogenic potential of stem cells

The extracellular matrix is a highly complex microenvironment, whose various components converge to regulate cell fate. Hydrogels, as water-swollen polymer networks composed by synthetic or natural materials, are ideal candidates to create biologically active substrates that mimic these matrices and target cell behaviour for a desired tissue engineering application. Indeed, the ability to tune their mechanical, structural, and biochemical properties provides a framework to recapitulate native tissues. This review explores how hydrogels have been engineered to harness the chondrogenic response of stem cells for the repair of damaged cartilage tissue. The signalling processes involved in hydrogel-driven chondrogenesis are also discussed, identifying critical pathways that should be taken into account during hydrogel design.

Multiscale Regulation of the Intervertebral Disc: Achievements in Experimental, In Silico, and Regenerative Research

Intervertebral disc (IVD) degeneration is a major risk factor of low back pain. It is defined by a progressive loss of the IVD structure and functionality, leading to severe impairments with restricted treatment options due to the highly demanding mechanical exposure of the IVD. Degenerative changes in the IVD usually increase with age but at an accelerated rate in some individuals. To understand the initiation and progression of this disease, it is crucial to identify key top-down and bottom-up regulations' processes, across the cell, tissue, and organ levels, in health and disease. Owing to unremitting investigation of experimental research, the comprehension of detailed cell signaling pathways and their effect on matrix turnover significantly rose. Likewise, in silico research substantially contributed to a holistic understanding of spatiotemporal effects and complex, multifactorial interactions within the IVD. Together with important achievements in the research of biomaterials, manifold promising approaches for regenerative treatment options were presented over the last years. This review provides an integrative analysis of the current knowledge about (1) the multiscale function and regulation of the IVD in health and disease, (2) the possible regenerative strategies, and (3) the in silico models that shall eventually support the development of advanced therapies.

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.

p38MAPK controls fibroblast growth factor 23 (FGF23) synthesis in UMR106-osteoblast-like cells and in IDG-SW3 osteocytes

BACKGROUND

p38 mitogen-activated protein kinase (p38MAPK) is a serine/threonine kinase activated by cellular stress stimuli including radiation, osmotic shock, and inflammation and influencing apoptosis, cell proliferation, and autophagy. Moreover, p38MAPK induces transcriptional activity of the transcription factor complex NFκB mediating multiple pro-inflammatory cellular responses. Fibroblast growth factor 23 (FGF23) is produced by bone cells, and regulates renal phosphate and vitamin D metabolism as a hormone. FGF23 expression is enhanced by NFκB. Here, we analyzed the relevance of p38MAPK activity for the production of FGF23.

METHODS

Fgf23 expression was analyzed by qRT-PCR and FGF23 protein by ELISA in UMR106 osteoblast-like cells and in IDG-SW3 osteocytes.

RESULTS

Inhibition of p38MAPK with SB203580 or SB202190 significantly down-regulated Fgf23 expression and FGF23 protein expression. Conversely, p38MAPK activator anisomycin increased the abundance of Fgf23 mRNA. NFκB inhibitors wogonin and withaferin A abrogated the stimulatory effect of anisomycin on Fgf23 gene expression.

CONCLUSION

p38MAPK induces FGF23 formation, an effect at least in part dependent on NFκB activity.

The wonders of BMP9: From mesenchymal stem cell differentiation, angiogenesis, neurogenesis, tumorigenesis, and metabolism to regenerative medicine

Although bone morphogenetic proteins (BMPs) initially showed effective induction of ectopic bone growth in muscle, it has since been determined that these proteins, as members of the TGF-β superfamily, play a diverse and critical array of biological roles. These roles include regulating skeletal and bone formation, angiogenesis, and development and homeostasis of multiple organ systems. Disruptions of the members of the TGF-β/BMP superfamily result in severe skeletal and extra-skeletal irregularities, suggesting high therapeutic potential from understanding this family of BMP proteins. Although it was once one of the least characterized BMPs, BMP9 has revealed itself to have the highest osteogenic potential across numerous experiments both in vitro and in vivo, with recent studies suggesting that the exceptional potency of BMP9 may result from unique signaling pathways that differentiate it from other BMPs. The effectiveness of BMP9 in inducing bone formation was recently revealed in promising experiments that demonstrated efficacy in the repair of critical sized cranial defects as well as compatibility with bone-inducing bio-implants, revealing the great translational promise of BMP9. Furthermore, emerging evidence indicates that, besides its osteogenic activity, BMP9 exerts a broad range of biological functions, including stem cell differentiation, angiogenesis, neurogenesis, tumorigenesis, and metabolism. This review aims to summarize our current understanding of BMP9 across biology and the body.

CXCR4-Receptor-Targeted Liposomes for the Treatment of Peritoneal Fibrosis

Peritoneal fibrosis (PF) is a common complication of long-term peritoneal dialysis (PD). It is considered as the main reason for dialysis inadequacy and PD withdrawal. Transforming growth factor beta (TGF-β) regulates the expression of stromal cell-derived factor 1 (SDF-1α) and its receptor C-X-C chemokine receptor type 4 (CXCR4) on human peritoneal mesothelial cells (HPMCs), resulting in an increased migratory potential of HPMCs and extracellular matrix (ECM) deposition in the scar tissue and eventually fibrosis. Because SDF-1α/CXCR4 activation has a vital role in the pathogenesis of PF, codelivery of a CXCR4-receptor targeting agent with an antifibrotic agent in a single nanocarrier can be a promising strategy for treating PF. Here, for the first time, AMD3100 (AMD), a CXCR4-receptor antagonist, was coformulated with sulfotanshinone IIA sodium (STS IIA) into a liposome (STS-AMD-Lips) to develop a CXCR4 receptor targeting form of combination therapy for PF. CXCR4 targeting increased the ability of liposomes to target fibrotic peritoneal mesothelial cells overexpressing CXCR4 and facilitated the ability of STS IIA treatment at the fibrotic site. The liposome had an average diameter of 103 nm with encapsulated efficiencies of above 50%. The in vivo studies confirmed the reversal of PD solution-induced epithelial-to-mesenchymal transition by STS-AMD-Lips in HPMCs. The in vivo studies also revealed the precise biodistribution of the liposomes to peritoneum. Significant reduction of the morphological lesions and decreased level of ECM proteins were observed in rats treated with STS-AMD-Lips, proving that the liposomal nanocarrier has excellent ability to reverse PF. It has been concluded that the STS-AMD-Lips exhibit specific peritoneal targeting ability and could be used to improve STS-AMD combination delivery for the treatment of PF.

Dihydromyricetin induces apoptosis in a human choriocarcinoma cell line

Choriocarcinoma is a malignant trophoblastic tumor. The development of novel drugs is required to reduce the toxicity of current multi-agent chemotherapy and to successfully treat chemoresistant cases of the disease. The purpose of the present study was to investigate the effect of dihydromyricetin (DMY) on the human choriocarcinoma cell line, JAr, to identify a novel drug for the treatment of choriocarcinoma. An MTT assay was performed to determine the effects of DMY at different concentrations and for different exposure durations. Flow cytometry and TUNEL assays were performed to detect apoptosis, and western blotting was utilized to investigate the underlying mechanism. The results revealed that DMY significantly inhibited JAr cell viability in a time- and dose-dependent manner. The flow cytometry and TUNEL assays demonstrated that DMY inhibited proliferation by inducing apoptosis. Further analysis by western blotting indicated that the protein expression level of BCL-2 associated X, associated protein increased, while the protein expression levels of BCL-2 and pro-caspase-3 decreased. These findings suggest that DMY induced apoptosis in human choriocarcinoma JAr cells, through a mitochondrially mediated apoptotic pathway.

Compound Astragalus and Salvia miltiorrhiza extract inhibits hepatocarcinogenesis via modulating TGF-β/TβR and Imp7/8

Compound Astragalus and Salvia miltiorrhiza extract (CASE) is a Chinese herbal formula consisting of astragalosides, astragalus polysaccharide and salvianolic acids extracted from Astragalus membranaceus and Salvia miltiorhiza. Previous studies by our group have demonstrated that CASE effectively suppresses diethylinitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in rats via modulating transforming growth factor β/Mothers against decapentaplegic (TGFβ/Smad) signaling. To further elucidate the mechanism of CASE, the effects of CASE on TGF-β₁, the serine/threonine kinase receptors of TGF-β [TGF-β receptor type-I (TβRI) and TβRII] and karyopherins [Importin 7 (Imp7) and Imp8], which are crucial for TGF-β/Smad signaling in fibro-hepatocarcinogenesis, were assessed in the present study using in vivo (DEN-induced HCC in rats) and in vitro [TGF-β₁-stimulated rat myofibroblasts (MFBs) and HepG2 cells] models of fibro-hepatocarcinogenesis. Hematoxylin and eosin staining revealed that CASE may suppress inflammatory reactions and fibrosis in HCC as well as increasing the differentiation of HCC cells. Positive TGF-β₁ staining was increased in HCC nodule areas and in adjacent normal liver tissues in DEN-treated rats, while TβRI staining was increased only in normal adjacent liver tissues. The elevated expression of TGF-β₁, TβRI and TβRII was suppressed by CASE. CASE treatment also reduced glutathione S-transferase P 1 and Imp7/8 protein expression in fibro-hepatocarcinogenesis. In vitro experiments confirmed that CASE was able to decrease the expression of TβRI and TβRII in TGF-β₁-stimulated MFBs and HepG2 cells. These results indicate that the anti-HCC effect of CASE may be achieved by mediating TGF-β/TβR and Imp7/8 protein expression, suggesting that CASE has multiple targets in HCC treatment.

p38 MAPK Inhibition Improves Heart Function in Pressure-Loaded Right Ventricular Hypertrophy

Although p38 mitogen-activated protein kinase (MAPK) is known to have a role in ischemic heart disease and many other diseases, its contribution to the pathobiology of right ventricular (RV) hypertrophy and failure is unclear. Therefore, we sought to investigate the role of p38 MAPK in the pathophysiology of pressure overload-induced RV hypertrophy and failure. The effects of the p38 MAPK inhibitor PH797804 were investigated in mice with RV hypertrophy/failure caused by exposure to hypoxia or pulmonary artery banding. In addition, the effects of p38 MAPK inhibition or depletion (by small interfering RNA) were studied in isolated mouse RV fibroblasts. Echocardiography, invasive hemodynamic measurements, immunohistochemistry, collagen assays, immunofluorescence staining, and Western blotting were performed. Expression of phosphorylated p38 MAPK was markedly increased in mouse and human hypertrophied/failed RVs. In mice, PH797804 improved RV function and inhibited cardiac fibrosis compared with placebo. In isolated RV fibroblasts, p38 MAPK inhibition reduced transforming growth factor (TGF)-β-induced collagen production as well as stress fiber formation. Moreover, p38 MAPK inhibition/depletion suppressed TGF-β-induced SMAD2/3 phosphorylation and myocardin-related transcription factor A (MRTF-A) nuclear translocation, and prevented TGF-β-induced cardiac fibroblast transdifferentiation. Moreover, p38 MAPK inhibition in mice exposed to pulmonary artery banding led to diminished nuclear levels of MRTF-A and phosphorylated SMAD3 in RV fibroblasts. Together, our data indicate that p38 MAPK inhibition significantly improves RV function and inhibits RV fibrosis. Inhibition of p38 MAPK in RV cardiac fibroblasts, resulting in coordinated attenuation of MRTF-A cytoplasmic-nuclear translocation and SMAD3 deactivation, indicates that p38 MAPK signaling contributes to distinct disease-causing mechanisms.

Molecular Cloning and Characterization of a P38-Like Mitogen-Activated Protein Kinase from Echinococcus granulosus

Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus. We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus. Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens p38α, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for p38α. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with TGF-β1 effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus, as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human TGF-β1.

Salinomycin suppresses TGF-β1-induced epithelial-to-mesenchymal transition in MCF-7 human breast cancer cells

Epithelial-to-mesenchymal transition (EMT) is the major cause of breast cancer to initiate invasion and metastasis. Salinomycin (Sal) has been found as an effective chemical compound to kill breast cancer stem cells. However, the effect of Sal on invasion and metastasis of breast cancer is unclear. In the present study, we showed that Sal reversed transforming growth factor-β1 (TGF-β1) induced invasion and metastasis accompanied with down-regulation of MMP-2 by experiments on human breast cancer cell line MCF-7. Sal was able to inhibit TGF-β1-induced EMT phenotypic transition and the activation of key signaling molecules involved in Smad (p-Smad2/3,Snail1) and non-Smad (β-catenin, p-p38 MAPK) signals which cooperatively regulate the induction of EMT. Importantly, in a series of breast cancer specimens, we found strong correlation among E-cadherin expression, β-catenin expression, and the lymph node metastatic potential of breast cancer. Our research suggests that Sal is promised to be a chemotherapeutic drug by suppressing the metastasis of breast cancer.

Short hairpin RNA silencing of TGF-βRII and FZD-7 synergistically suppresses proliferation and metastasis of hepatocellular carcinoma cells

Transforming growth factor-β (TGF-β) is a multifunctional regulator of cell growth, apoptosis, differentiation and migration. The Wnt/β-catenin signaling pathway has been implicated in a wide spectrum of diseases, including numerous cancers and degenerative disease. The aim of the present study was to investigate if simultaneous blocking of TGF-β and Wnt/β-catenin signaling pathways exerts synergistic anti-tumor effects on hepatocellular carcinoma (HCC) cells. Short hairpin (sh) RNA eukaryotic expression vectors, specific to TGF-β receptor II (RII) and Frizzled receptor (FZD)-7, were constructed by gene recombination. The expression vectors were transfected into human HCC HepG2 and Huh-7 cells using Lipofectamine 2000 to investigate the synergistic effects between TGF-β and Wnt/β-catenin signaling pathways on HCC cell proliferation, invasion and migration and the cell-cycle distribution. Western blot analysis was used to identify the expression of β-catenin, c-Myc and cyclin D1 in transfected cells to investigate the underlying mechanisms that cause TGF-β and Wnt/β-catenin signaling in HCC cells. shTGF-βRII-c and shFZD-7-2 were selected as the most efficient plasmids. A cell growth assay and colony-forming assay consistently demonstrated that the proliferative activity of the co-transfected group was significantly decreased compared to the single-transfected group. A wound healing invasion and migration assay demonstrated that co-transfection of shTGF-βRII-c and shFZD-7-2 decreased the invasion and migration abilities of the cells compared with either single-transfected group. In addition, the present study demonstrated that the observed reduction in cell proliferation was due to the cells arresting at the G1 phase of the cell cycle, and the downregulation of β-catenin, c-Myc and cyclin D1 impaired the proliferative and invasive abilities of the HCC cells. The present results demonstrate that simultaneous blocking of TGF-β and Wnt/β-catenin signaling by targeting TGF-βRII and FZD-7 may inhibit the proliferation and metastasis of HCC cells more effectively compared with blocking either the TGF-β or Wnt/β-catenin pathway.

RNA-Seq and Network Analysis Revealed Interacting Pathways in TGF-β-Treated Lung Cancer Cell Lines

Whole transcriptome shotgun sequencing (RNA-Seq) is a useful tool for analyzing the transcriptome of a biological sample. With appropriate statistical and bioinformatic processing, this platform is capable of identifying significant differences in gene expression within the transcriptome and permits pathway and network analyses to determine how these genes interact biologically. In this study, we examined gene expression in two lung adenocarcinoma cell lines (H358 and A459) that were treated with transforming growth factor-β (TGF-β) as a model for induction of the epithelial-to-mesenchymal transition (EMT), commonly associated with disease progression. We performed this study in order to illustrate a workflow for identifying interesting genes and processes that are regulated early in EMT and to determine their gene pathway/network relationships and regulation. With this, we identified 137 upregulated and 32 downregulated genes common to both cell lines after TGF-β treatment that represent components of multiple canonical pathways and biological networks associated with the induction of EMT. These findings were also verified against reposited Affymetrix U133a expression profiles from multiple trials examining metastatic progression in patient cohorts (n = 731 total) to further establish the clinical relevance and translational significance of the model system. Together, these findings help validate the relevance of the TGF-β model for the study of EMT and provide new insights into early events in EMT.