Blocking transforming growth factor-beta up-regulates E-cadherin and reduces migration and invasion of hepatocellular carcinoma cells

Role of transforming growth factor-β1 pathway in angiogenesis induced by chronic stress in colorectal cancer

BACKGROUND

Chronic stress can induce stress-related hormones; norepinephrine (NE) is considered to have the highest potential in cancer. NE can stimulate the expression of hypoxia-inducible factor-1α (HIF-1α), which is associated with vascular endothelial growth factor (VEGF) secretion and tumor angiogenesis. However, the underlying mechanisms are poorly understood.

METHODS

Tumor-bearing mice were subjected to chronic restraint stress and treated with normal saline, human monoclonal VEGF-A neutralizing antibody bevacizumab, or β-adrenergic receptor (β-AR) antagonist (propranolol). Tumor growth and vessel density were also evaluated. Human colorectal adenocarcinoma cells were treated with NE, propranolol, or the inhibitor of transforming growth factor-β (TGF-β) receptor Type I kinase (Ly2157299) in vitro. TGF-β1 in mouse serum and cell culture supernatants was quantified using ELISA. The expression of HIF-1α was measured using Real time-PCR and western blotting. Cell migration and invasion were tested.

RESULTS

Chronic restraint stress attenuated the efficacy of bevacizumab and promoted tumor growth and angiogenesis in a colorectal tumor model. Propranolol blocked this effect and inhibited TGF-β1 elevation caused by chronic restraint stress or NE. NE upregulated HIF-1α expression, which was reversed by propranolol or Ly2157299. Propranolol and Ly2157199 blocked NE-stimulated cancer cell migration and invasion.

CONCLUSIONS

Our results demonstrate the effect of NE on tumor angiogenesis and the critical role of TGF-β1 signaling during this process. In addition, β-AR/TGF-β1 signaling/HIF-1α/VEGF is a potential signaling pathway. This study also indicates that psychosocial stress might be a risk factor which weakens the efficacy of anti-angiogenic therapy.

Infiltrative Vessel Co-optive Growth Pattern Induced by IQGAP3 Overexpression Promotes Microvascular Invasion in Hepatocellular Carcinoma

PURPOSE

Microvascular invasion (MVI) is a major unfavorable prognostic factor for intrahepatic metastasis and postoperative recurrence of hepatocellular carcinoma (HCC). However, the intervention and preoperative prediction for MVI remain clinical challenges due to the absent precise mechanism and molecular marker(s). Herein, we aimed to investigate the mechanisms underlying vascular invasion that can be applied to clinical intervention for MVI in HCC.

EXPERIMENTAL DESIGN

The histopathologic characteristics of clinical MVI+/HCC specimens were analyzed using multiplex immunofluorescence staining. The liver orthotopic xenograft mouse model and mechanistic experiments on human patient-derived HCC cell lines, including coculture modeling, RNA-sequencing, and proteomic analysis, were used to investigate MVI-related genes and mechanisms.

RESULTS

IQGAP3 overexpression was correlated significantly with MVI status and reduced survival in HCC. Upregulation of IQGAP3 promoted MVI+-HCC cells to adopt an infiltrative vessel co-optive growth pattern and accessed blood capillaries by inducing detachment of activated hepatic stellate cells (HSC) from the endothelium. Mechanically, IQGAP3 overexpression contributed to HCC vascular invasion via a dual mechanism, in which IQGAP3 induced HSC activation and disruption of the HSC-endothelial interaction via upregulation of multiple cytokines and enhanced the trans-endothelial migration of MVI+-HCC cells by remodeling the cytoskeleton by sustaining GTPase Rac1 activity. Importantly, systemic delivery of IQGAP3-targeting small-interfering RNA nanoparticles disrupted the infiltrative vessel co-optive growth pattern and reduced the MVI of HCC.

CONCLUSIONS

Our results revealed a plausible mechanism underlying IQGAP3-mediated microvascular invasion in HCC, and provided a potential target to develop therapeutic strategies to treat HCC with MVI.

Ginkgolide B Blocks Vascular Remodeling after Vascular Injury via Regulating Tgfβ1/Smad Signaling Pathway

Coronary artery disease (CAD) is the most prevalent cardiovascular disease worldwide, resulting in myocardial infarction (MI) and even sudden death. Following percutaneous coronary intervention (PCI), restenosis caused by vascular remodeling is always formed at the stent implantation site. Here, we show that Ginkgolide B (GB), a naturally occurring terpene lactone, effectively suppresses vascular remodeling and subsequent restenosis in wild-type mice following left carotid artery (LCA) injury. Additional experiments reveal that GB exerts a protective effect on vascular remodeling and further restenosis through modulation of the Tgfβ1/Smad signaling pathway in vivo and in human vascular smooth muscle cells (HVSMAs) but not in human umbilical vein endothelial cells (HUVECs) in vitro. Moreover, the beneficial effect of GB is abolished after incubated with pirfenidone (PFD, a drug for idiopathic pulmonary fibrosis, IPF), which can inhibit Tgfβ1. In Tgfβ1-/- mice, treatment with pirfenidone capsules and Yinxingneizhi Zhusheye (including Ginkgolide B) fails to improve vascular remodeling and restenosis. In conclusion, our data identify that GB could be a potential novel therapeutic agent to block vessel injury-associated vascular remodeling and further restenosis and show significant repression of Tgfβ1/Smad signaling pathway.

Colorectal Liver Metastasis: Can Cytokines Make the Difference?

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. Metastasis is the prime driver of CRC-related mortality, and the liver is the organ most frequently involved. Despite the overall success of current treatments, colorectal liver metastasis (CRLM) is associated with poor prognoses and a survival rate of only 14%. Recent studies have highlighted the importance of the tumor microenvironment (TME) and the crosstalk within it in determining the invasion of distant organs by circulating cancer cells. In the TME, cellular communication is mediated via soluble molecules, among which cytokines have recently emerged as key regulators, involved in every aspect of tumor progression and the metastatic cascade. Indeed, in the serum of CRC patients elevated levels of several cytokines are associated with cancer development and progression. The current review evaluates the role of different cytokines during CRLM development. Additionally, considering the increasing amount of data concerning the importance of cytokine complex networks, we outline the potential of combination treatments using targeted cytokines together with other well-established therapies, such as immune checkpoint blockades, chemotherapy, or gene therapy, to improve therapeutic outcomes.

Laminin-332 γ2 Monomeric Chain Promotes Adhesion and Migration of Hepatocellular Carcinoma Cells

Extracellular matrix (ECM) has a well-recognized impact on the progression of solid tumors, including hepatocellular carcinoma (HCC). Laminin 332 (Ln332) is a ECM molecule of epithelial basal lamina, composed of three polypeptide chains (α3, β3, and γ2), that is usually poorly expressed in the normal liver but is detected at high levels in HCC. This macromolecule was shown to promote the proliferation, epithelial-to-mesenchymal transition (EMT), and drug resistance of HCC cells. The monomeric γ2 chain is up-regulated and localized preferentially at the invasive edge of metastatic intrahepatic HCC nodules, suggesting its potential involvement in the acquisition of invasive properties of HCC cells. HCC cells were tested in in vitro adhesion, scattering, and transwell migration assays in response to fibronectin and the Ln332 and Ln332 γ2 chains, and the activation status of major signaling pathways involved was evaluated. Here, we show that the Ln332 γ2 chain promotes HCC the cell adhesion, migration, and scattering of HCC cells that express the Ln332 receptor α3β1 integrin, proving to be a causal factor of the EMT program achievement. Moreover, we found that efficient HCC cell adhesion and migration on γ2 require the activation of the small cytosolic GTPase Rac1 and ERKs signaling. These data suggest that the γ2 chain, independently from the full-length Ln332, can contribute to the pro-invasive potential of aggressive HCC cell subpopulations.

Implications of Possible HBV-Driven Regulation of Gene Expression in Stem Cell-like Subpopulation of Huh-7 Hepatocellular Carcinoma Cell Line

Elevated levels of STIM1, an endoplasmic reticulum Ca²⁺ sensor/buffering protein, appear to be correlated with poor cancer prognosis in which microRNAs are also known to play critical roles. The purpose of this study is to investigate possible HBV origins of specific microRNAs we identified in a stem cell-like subpopulation of Huh-7 hepatocellular carcinoma (HCC) cell lines with enhanced STIM1 and/or Orai1 expression that mimicked poor cancer prognosis. Computational strategies including phylogenetic analyses were performed on miRNome data we obtained from an EpCAM- and CD133-expressing Huh-7 HCC stem cell-like subpopulation with enhanced STIM1 and/or Orai1 expression originally cultured in the present work. Results revealed two putative regions in the HBV genome based on the apparent clustering pattern of stem loop sequences of microRNAs, including miR3653. Reciprocal analysis of these regions identified critical human genes, of which their transcripts are among the predicted targets of miR3653, which was increased significantly by STIM1 or Orai1 enhancement. Briefly, this study provides phylogenetic evidence for a possible HBV-driven epigenetic remodeling that alters the expression pattern of Ca²⁺ homeostasis-associated genes in STIM1- or Orai1 overexpressing liver cancer stem-like cells for a possible mutual survival outcome. A novel region on HBV-X protein may affect liver carcinogenesis in a genotype-dependent manner. Therefore, detection of the viral genotype would have a clinical impact on prognosis of HBV-induced liver cancers.

Deciphering the role of transforming growth factor-beta 1 as a diagnostic-prognostic-therapeutic candidate against hepatocellular carcinoma

Transforming growth factor-beta (TGF-β) is a multifunctional cytokine that performs a dual role as a tumor suppressor and tumor promoter during cancer progression. Among different ligands of the TGF-β family, TGF-β1 modulates most of its biological outcomes. Despite the abundant expression of TGF-β1 in the liver, steatosis to hepatocellular carcinoma (HCC) progression triggers elevated TGF-β1 levels, contributing to poor prognosis and survival. Additionally, elevated TGF-β1 levels in the tumor microenvironment create an immunosuppressive stage via various mechanisms. TGF-β1 has a prime role as a diagnostic and prognostic biomarker in HCC. Moreover, TGF-β1 is widely studied as a therapeutic target either as monotherapy or combined with immune checkpoint inhibitors. This review provides clinical relevance and up-to-date information regarding the potential of TGF-β1 in diagnosis, prognosis, and therapy against HCC.

Advances in novel systemic therapies for advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most frequent type of primary liver tumor. Most HCC patients present with advanced disease at diagnosis and the recurrence rate after surgery remains high. Treatment options for advanced HCC are limited, with sorafenib representing the only systemic agent approved for treatment of advanced HCC in more than a decade. However, in recent years new molecular targeted therapies and immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced HCC. In particular, combinations of ICIs with antiangiogenic drugs, or with other ICIs, represent one of the most promising strategies. Herein we provide a comprehensive overview of the main therapeutic advances in the systemic treatment of HCC, focusing on the most relevant ongoing clinical trials.

Dysregulated glucuronic acid metabolism exacerbates hepatocellular carcinoma progression and metastasis through the TGFβ signalling pathway

BACKGROUND

Glucuronic acid metabolism participates in cellular detoxification, extracellular matrix remodeling and cell adhesion and migration. Here, we aimed to explore the crosstalk between dysregulated glucuronic acid metabolism and crucial metastatic signalling in glutathione S-transferase zeta 1 (GSTZ1)-deficient hepatocellular carcinoma (HCC).

METHODS

Transwell, HCC xenograft and Gstz1-/- mouse models were used to examine the role of GSTZ1 in HCC metastasis. Non-targeted and targeted metabolomics and global transcriptomic analyses were performed to screen significantly altered metabolic and signalling pathways in GSTZ1 overexpressing hepatoma cells. Further, RNA-binding protein immunoprecipitation, Biotin-RNA pull-down, mRNA decay assays and luciferase reporter assays were used to explore the interaction between RNA and RNA-binding proteins.

RESULTS

GSTZ1 was universally silenced in both human and murine HCC cells, and its deficiency contributed to HCC metastasis in vitro and in vivo. UDP-glucose 6-dehydrogenase (UGDH)-mediated UDP-glucuronic acid (UDP-GlcUA) accumulation promoted hepatoma cell migration upon GSTZ1 loss. UDP-GlcUA stabilized TGFβR1 mRNA by enhancing its binding to polypyrimidine tract binding protein 3, contributing to the activation of TGFβ/Smad signalling. UGDH or TGFβR1 blockade impaired HCC metastasis. In addition, UGDH up-regulation and UDP-GlcUA accumulation correlated with increased metastatic potential and decreased patient survival in GSTZ1-deficient HCC.

CONCLUSIONS

GSTZ1 deficiency and subsequent up-regulation of the glucuronic acid metabolic pathway promotes HCC metastasis by increasing the stability of TGFβR1 mRNA and activating TGFβ/Smad signalling. UGDH and a key metabolite, UDP-GlcUA, may serve as prognostic markers. Targeting UGDH might be a promising strategy for HCC therapy.

The S100 calcium binding protein A11 promotes liver fibrogenesis by targeting TGF-β signaling

Liver fibrosis is a key transformation stage and also a reversible pathological process in various types of chronic liver diseases. However, the pathogenesis of liver fibrosis still remains elusive. Here, we report that the calcium binding protein A11 (S100A11) is consistently upregulated in the integrated data from GSE liver fibrosis and tree shrew liver proteomics. S100A11 is also experimentally activated in liver fibrosis in mouse, rat, tree shrew, and human with liver fibrosis. While overexpression of S100A11 in vivo and in vitro exacerbates liver fibrosis, the inhibition of S100A11 improves liver fibrosis. Mechanistically, S100A11 activates hepatic stellate cells (HSCs) and the fibrogenesis process via the regulation of the deacetylation of Smad3 in the TGF-β signaling pathway. S100A11 physically interacts with SIRT6, a deacetylase of Smad2/3, which may competitively inhibit the interaction between SIRT6 and Smad2/3. The subsequent release and activation of Smad2/3 promote the activation of HSCs and fibrogenesis. Additionally, a significant elevation of S100A11 in serum is observed in clinical patients. Our study uncovers S100A11 as a novel profibrogenic factor in liver fibrosis, which may represent both a potential biomarker and a promising therapy target for treating liver fibrosis and fibrosis-related liver diseases.

Identification of a TGF-β/SMAD/lnc-UTGF positive feedback loop and its role in hepatoma metastasis

Aberrant activation of the TGF-β/SMAD signaling pathway is often observed in hepatocellular carcinoma (HCC). Whether lncRNA regulates the TGF-β/SMAD signaling remains largely unknown. Here, we identified an oncogenic lncRNA that was upregulated in HCC and was transcriptionally induced by TGF-β (named lnc-UTGF, lncRNA upregulated by TGF-β). Upon TGF-β stimulation, SMAD2/3 bound to the lnc-UTGF promoter and activated lnc-UTGF expression. In turn, the TGF-β/SMAD signaling was augmented by overexpressing lnc-UTGF, but was inhibited by silencing lnc-UTGF. Mechanism investigations revealed that lnc-UTGF interacted with the mRNAs of SMAD2 and SMAD4 via complementary base-pairing, resulting in enhanced stability of SMAD2/4 mRNAs. These data suggest a novel TGF-β/SMAD/lnc-UTGF positive feedback circuitry. Subsequent gain- and loss-of-function analyses disclosed that lnc-UTGF promoted the migration and invasion of hepatoma cells, and this effect of lnc-UTGF was attenuated by repressing SMAD2/4 expression or by mutating the SMAD2/4-binding sites in lnc-UTGF. Studies using mouse models further confirmed that in vivo metastasis of hepatoma xenografts was inhibited by silencing lnc-UTGF, but was enhanced by ectopic expression of lnc-UTGF. The lnc-UTGF level was positively correlated with the SMAD2/4 levels in xenografts. Consistently, we detected an association of lnc-UTGF upregulation with increase of SMAD2, SMAD4, and their metastasis effector SNAIL1 in human HCC. And high lnc-UTGF level was also significantly associated with enhanced metastasis potential, advanced TNM stages, and worse recurrence-free survival. Conclusion: there exists a lnc-UTGF-mediated positive feedback loop of the TGF-β signaling and its deregulation promotes hepatoma metastasis. These findings may provide a new therapeutic target for HCC metastasis.

The effect of macrophage polarization on the expression of the oxytocin signalling system in enteric neurons

BACKGROUND

The aim of the current study was to investigate the effect of macrophage polarization on the expression of oxytocin (OT) and the oxytocin receptor (OTR) in enteric neurons.

METHODS

In this study, we used a classic colitis model and D-mannose model to observe the correlation between macrophage polarization and OT signalling system. In order to further demonstrate the effect of macrophages, we examined the expression of OT signalling system after depletion of macrophages.

RESULTS

The data showed that, in vitro, following polarization of macrophages to the M1 type by LPS, the macrophage supernatant contained proinflammatory cytokines (IL-1β, IL-6 and TNF-α) that inhibited the expression of OT and OTR in cultured enteric neurons; following macrophage polarization to the M2 type by IL4, the macrophage supernatant contained anti-inflammatory cytokines (TGF-β) that promoted the expression of OT and OTR in cultured enteric neurons. Furthermore, M1 macrophages decreased the expression of the OT signalling system mainly through STAT3/NF-κB pathways in cultured enteric neurons; M2 macrophages increased the expression of the OT signalling system mainly through activation of Smad2/3 and inhibition of the expression of Peg3 in cultured enteric neurons. In a colitis model, we demonstrated that macrophages were polarized to the M1 type during the inflammatory phase, with significant decreased in the expression of OT and OTR. When macrophages were polarized to the M2 type during the recovery phase, OT and OTR expression increased significantly. In addition, we found that D-mannose increased the expression of OT and OTR through polarization of macrophages to the M2 type.

CONCLUSIONS

This is the first study to demonstrate that macrophage polarization differentially regulates the expression of OT and OTR in enteric neurons.

Direct and Indirect Effect of TGFβ on Treg Transendothelial Recruitment in HCC Tissue Microenvironment

The balance between anti-tumor and tumor-promoting immune cells, such as CD4+ Th1 and regulatory T cells (Tregs), respectively, is assumed to dictate the progression of hepatocellular carcinoma (HCC). The transforming growth factor beta (TGFβ) markedly shapes the HCC microenvironment, regulating the activation state of multiple leukocyte subsets and driving the differentiation of cancer associated fibroblasts (CAFs). The fibrotic (desmoplastic) reaction in HCC tissue strongly depends on CAFs activity. In this study, we attempted to assess the role of TGFβ on transendothelial migration of Th1-oriented and Treg-oriented CD4+ T cells via a direct or indirect, CAF-mediated mechanisms, respectively. We found that the blockage of TGFβ receptor I-dependent signaling in Tregs resulted in impaired transendothelial migration (TEM) of these cells. Interestingly, the secretome of TGFβ-treated CAFs inhibited the TEM of Tregs but not Th1 cells, in comparison to the secretome of untreated CAFs. In addition, we found a significant inverse correlation between alpha-SMA and FoxP3 (marker of Tregs) mRNA expression in a microarray analysis involving 78 HCCs, thus suggesting that TGFβ-activated stromal cells may counteract the trafficking of Tregs into the tumor. The apparent dual behavior of TGFβ as both pro- and anti-tumorigenic cytokines may add a further level of complexity to the mechanisms that regulate the interactions among cancerous, stromal, and immune cells within HCC, as well as other solid tumors, and contribute to better manipulation of the TGFβ signaling as a therapeutic target in HCC patients.

ZEB1 serves an oncogenic role in the tumourigenesis of HCC by promoting cell proliferation, migration, and inhibiting apoptosis via Wnt/β-catenin signaling pathway

Zinc finger E-box-binding homeobox 1 (ZEB1), a functional protein of zinc finger family, was aberrant expressed in many kinds of liver disease including hepatic fibrosis and Hepatitis C virus. Bioinformatics results showed that ZEB1 was abnormally expressed in HCC tissues. However, to date, the potential regulatory role and molecular mechanisms of ZEB1 are still unclear in the occurrence and development of HCC. This study demonstrated that the expression level of ZEB1 was significantly elevated both in liver tissues of HCC patients and cell lines (HepG2 and SMMC-7721 cells). Moreover, ZEB1 could promote the proliferation, migration, and invasion of HCC cells. On the downstream regulation mechanism, ZEB1 could activate the Wnt/β-catenin signaling pathway by upregulating the protein expression levels of β-catenin, c-Myc, and cyclin D1. Novel studies showed that miR-708 particularly targeted ZEB1 3'-UTR regions and inhibited the HCC cell proliferation, migration, and invasion. Furthermore, results of nude mice experiments of HCC model indicated that miR-708 could inhibit tumor growth and xenograft metastasis model was established to validate that miR-708 could inhibit HCC cell metastasis through tail-vein injection in vivo. Together, the study suggested that ZEB1 modulated by miR-708 might be a potential therapeutic target for HCC therapy.

Radiation-Induced Overexpression of TGFβ and PODXL Contributes to Colorectal Cancer Cell Radioresistance through Enhanced Motility

The primary cause of colorectal cancer (CRC) recurrence is increased distant metastasis after radiotherapy, so there is a need for targeted therapeutic approaches to reduce the metastatic-relapse risk. Dysregulation of the cell-surface glycoprotein podocalyxin-like protein (PODXL) plays an important role in promoting cancer-cell motility and is associated with poor prognoses for many malignancy types. We found that CRC cells exposed to radiation demonstrated increased TGFβ and PODXL expressions, resulting in increased migration and invasiveness due to increased extracellular matrix deposition. In addition, both TGFβ and PODXL were highly expressed in tissue samples from radiotherapy-treated CRC patients compared to those from patients without this treatment. However, it is unclear whether TGFβ and PODXL interactions are involved in cancer-progression resistance after radiation exposure in CRC. Here, using CRC cells, we showed that silencing PODXL blocked radiation-induced cell migration and invasiveness. Cell treatment with galunisertib (a TGFβ-pathway inhibitor) also led to reduced viability and migration, suggesting that its clinical use may enhance the cytotoxic effects of radiation and lead to the effective inhibition of CRC progression. Overall, the results demonstrate that downregulation of TGFβ and its-mediated PODXL may provide potential therapeutic targets for patients with radiotherapy-resistant CRC.

TGF-β Signaling in Liver, Pancreas, and Gastrointestinal Diseases and Cancer

Genetic alterations affecting transforming growth factor-β (TGF-β) signaling are exceptionally common in diseases and cancers of the gastrointestinal system. As a regulator of tissue renewal, TGF-β signaling and the downstream SMAD-dependent transcriptional events play complex roles in the transition from a noncancerous disease state to cancer in the gastrointestinal tract, liver, and pancreas. Furthermore, this pathway also regulates the stromal cells and the immune system, which may contribute to evasion of the tumors from immune-mediated elimination. Here, we review the involvement of the TGF-β pathway mediated by the transcriptional regulators SMADs in disease progression to cancer in the digestive system. The review integrates human genomic studies with animal models that provide clues toward understanding and managing the complexity of the pathway in disease and cancer.

Combinatorial Strategies to Target Molecular and Signaling Pathways to Disarm Cancer Stem Cells

Cancer is an urgent public health issue with a very huge number of cases all over the world expected to increase by 2040. Despite improved diagnosis and therapeutic protocols, it remains the main leading cause of death in the world. Cancer stem cells (CSCs) constitute a tumor subpopulation defined by ability to self-renewal and to generate the heterogeneous and differentiated cell lineages that form the tumor bulk. These cells represent a major concern in cancer treatment due to resistance to conventional protocols of radiotherapy, chemotherapy and molecular targeted therapy. In fact, although partial or complete tumor regression can be achieved in patients, these responses are often followed by cancer relapse due to the expansion of CSCs population. The aberrant activation of developmental and oncogenic signaling pathways plays a relevant role in promoting CSCs therapy resistance. Although several targeted approaches relying on monotherapy have been developed to affect these pathways, they have shown limited efficacy. Therefore, an urgent need to design alternative combinatorial strategies to replace conventional regimens exists. This review summarizes the preclinical studies which provide a proof of concept of therapeutic efficacy of combinatorial approaches targeting the CSCs.

Immunomodulation: An immune regulatory mechanism in carcinoma therapeutics

Cancer has been generally related to the possession of numerous mutations which interrupt important signaling pathways. Nevertheless, deregulated immunological signaling is considered as one of the key factors associated with the development and progression of cancer. The signaling pathways operate as modular network with different components interacting in a switch-like fashion with two proteins interplaying between each other leading to direct or indirect inhibition or stimulation of down-stream factors. Genetic, epigenetic, and transcriptomic alterations maintain the pathological conduit of different signaling pathways via affecting diverse mechanisms including cell destiny. At present, immunotherapy is one of the best therapies opted for cancer treatment. The cancer immunotherapy strategy includes harnessing the specificity and killing mechanisms of the immunological system to target and eradicate malignant cells. Targeted therapies utilizing several little molecules including Galunisertib, Astragaloside-IV, Melatonin, and Jervine capable of regulating key signaling pathways can effectively help in the management of different carcinomas.

The Role of TGF-β Signaling Pathways in Cancer and Its Potential as a Therapeutic Target

The transforming growth factor-β (TGF-β) signaling pathway mediates various biological functions, and its dysregulation is closely related to the occurrence of malignant tumors. However, the role of TGF-β signaling in tumorigenesis and development is complex and contradictory. On the one hand, TGF-β signaling can exert antitumor effects by inhibiting proliferation or inducing apoptosis of cancer cells. On the other hand, TGF-β signaling may mediate oncogene effects by promoting metastasis, angiogenesis, and immune escape. This review summarizes the recent findings on molecular mechanisms of TGF-β signaling. Specifically, this review evaluates TGF-β's therapeutic potential as a target by the following perspectives: ligands, receptors, and downstream signaling. We hope this review can trigger new ideas to improve the current clinical strategies to treat tumors related to the TGF-β signaling pathway.

Modeling Liver Organogenesis by Recreating Three-Dimensional Collective Cell Migration: A Role for TGFβ Pathway

Three-dimensional (3D) collective cell migration (CCM) is critical for improving liver cell therapies, eliciting mechanisms of liver disease, and modeling human liver development and organogenesis. Mechanisms of CCM differ in 2D vs. 3D systems, and existing models are limited to 2D or transwell-based systems, suggesting there is a need for improved 3D models of CCM. To recreate liver 3D CCM, we engineered in vitro 3D models based upon a morphogenetic transition that occurs during liver organogenesis, which occurs rapidly between E8.5 and E9.5 (mouse). During this morphogenetic transition, 3D CCM exhibits co-migration (multiple cell types), thick-strand interactions with surrounding septum transversum mesenchyme (STM), branching morphogenesis, and 3D interstitial migration. Here, we engineer several 3D in vitro culture systems, each of which mimics one of these processes in vitro. In mixed spheroids bearing both liver cells and uniquely MRC-5 (fetal lung) fibroblasts, we observed evidence of co-migration, and a significant increase in length and number of liver spheroid protrusions, which was highly sensitive to transforming growth factor beta 1 (TGFβ1) stimulation. In MRC-5-conditioned medium (M-CM) experiments, we observed dose-dependent branching morphogenesis associated with an upregulation of Twist1, which was inhibited by a broad TGFβ inhibitor. In models in which liver spheroids and MRC-5 spheroids were co-cultured, we observed complex strand morphogenesis, whereby thin, linear, 3D liver cell strands attach to the MRC-5 spheroid, anchor and thicken to form permanent and thick anchoring contacts between the two spheroids. In these spheroid co-culture models, we also observed spheroid fusion and strong evidence for interstitial migration. In conclusion, we present several novel cultivation systems that recreate distinct features of liver 3D CCM. These methodologies will greatly improve our molecular, cellular, and tissue-scale understanding of liver organogenesis, liver diseases like cancer, and liver cell therapy, and will also serve as a tool to bridge conventional 2D studies and preclinical in vivo studies.

B-cell receptor-associated protein 31 promotes migration and invasion in ovarian cancer cells

B cell receptor associated protein 31 (BAP31) is a member of the B cell receptor that functions as a transporter for numerous types of newly formed proteins from the endoplasmic reticulum to the Golgi apparatus. Previous studies found that that BAP31 serves an important role in the pathogenesis of malignancy but its specific effect on ovarian cancer is not clear. The present study aimed to investigate whether BAP31 affects ovarian cancer and its underlying mechanism. In the present study, ovarian cancer tissue, human ovarian normal epithelial cell line IOSE80 and five ovarian cancer cell lines (A2780, Hey-T30, COC1, SKOV3 and OVCAR3) underwent reverse transcription-quantitative PCR, western blotting, Cell Counting Kit-8, Transwell and co-immunoprecipitation (Co-IP) assay and transcriptome sequencing. Previous studies showed that compared with healthy tissues, the expression level of BAP31 protein was found to be significantly higher in various types of cancer tissues, implying that BAP31 may serve an important role in the pathogenesis of cancer. The present study found that BAP31 expression was upregulated in five ovarian cancer cell lines and ovarian cancer tissue, such that BAP31 knockdown [performed using two short hairpin (sh)RNA plasmids] decreased proliferation, invasion and migration. In addition, BAP31 knockdown was found to downregulate the expression of N-cadherin and upregulate the expression of E-cadherin on transcriptional level by controlling the nuclear aggregation of TWIST1, a transcriptional regulator of N-cadherin and E-cadherin. There was no interaction between BAP31 and E-cadherin or N-cadherin using Co-IP detection, while BAP31, E-cadherin and N-cadherin interacted with TWIST1 protein. E-cadherin and N-cadherin expression levels recovered when TWIST1 was overexpressed in the shBCAP31 cells. These results suggest that BAP31 can regulate the migration and invasion of ovarian cancer cells through the epithelial-mesenchymal transition pathway at the transcriptional level, which may be beneficial for the identification of potentially novel targets for ovarian cancer therapy.

Small interfering-high mobility group A2 attenuates epithelial-mesenchymal transition in thymic cancer cells via the Wnt/β-catenin pathway

Thymus carcinoma is one of the thymic epithelial neoplasms with high metastasis, which does not have any good treatment at present. High mobility group A2 (HMGA2) is highly expressed in a variety of malignant tumors, such as lung cancer, colon cancer and ovarian cancer and is closely related to tumor invasion and metastasis. The present study aimed to investigate the effect and mechanism of HMGA2 on epithelial-mesenchymal transition (EMT) in thymic cancer cells. IU-TAB-1, A549, HCT-116 and 293T cells were screened by testing the protein expression level of HMGA2 though western blotting and subjected to HMGA2 interference [small interfering (si)-HMGA2]. Cell proliferation was evaluated using the Cell Counting Kit-8 assay. Cell migration and invasion were detected using the Transwell assay. Cell apoptosis was examined using flow cytometry and β-catenin expression was observed by immunofluorescence. The levels of E-cadherin, vimentin, Wnt3a, Wnt5a and β-catenin proteins were determined by western blotting. Among the four cell lines tested, IU-TAB-1 cells demonstrated the highest expression of HMGA2 (P<0.05) and were hence selected for subsequent experiments. Compared with the control group (untransfected cells), si-HMGA2 resulted in significantly decreased proliferation, migration and invasion of IU-TAB-1 cells, whereas apoptosis was increased (P<0.05). The protein expression of vimentin, Wnt3a, Wnt5a and β-catenin was significantly decreased by si-HMGA2 compared with the control group (P<0.05), whereas E-cadherin expression was increased (P<0.05). After treatment with si-HMGA2 in combination with Wnt/β-catenin agonists (SKL2001) or inhibitors (XAV-939), EMT was respectively enhanced or inhibited in IU-TAB-1 cells. Overall, si-HMGA2 may attenuate EMT in thymic cancer cells and the mechanism may be related to the Wnt/β-catenin pathway.

MST4 negatively regulates the EMT, invasion and metastasis of HCC cells by inactivating PI3K/AKT/Snail1 axis

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and has a poor prognosis due to the high incidence of invasion and metastasis-related progression. However, the underlying mechanism remains elusive, and valuable biomarkers for predicting invasion, metastasis, and poor prognosis of HCC patients are still lacking.

Methods: Immunohistochemistry (IHC) was performed on HCC tissues (n = 325), and the correlations between MST4 expression of the clinical HCC tissues, the clinicopathologic features, and survival were further evaluated. The effects of MST4 on HCC cell migratory and invasive properties in vitro were evaluated by Transwell and Boyden assays. The intrahepatic metastasis mouse model was established to evaluate the HCC metastasis in vivo. The PI3K inhibitor, LY294002, and a specific siRNA against Snail1 were used to investigate the roles of PI3K/AKT pathway and Snail1 in MST4-regulated EMT, migration, and invasion of HCC cells, respectively.

Results: In this study, by comprehensively analyzing our clinical data, we discovered that low MST4 expression is highly associated with the advanced progression of HCC and serves as a prognostic biomarker for HCC patients of clinical-stage III-IV. Functional studies indicate that MST4 inactivation induces epithelial-to-mesenchymal transition (EMT) of HCC cells, promotes their migratory and invasive potential in vitro, and facilitates their intrahepatic metastasis in vivo, whereas MST4 overexpression exhibits the opposite phenotypes. Mechanistically, MST4 inactivation elevates the expression and nuclear translocation of Snail1, a key EMT transcription factor (EMT-TF), through the PI3K/AKT signaling pathway, thus inducing the EMT phenotype of HCC cells, and enhancing their invasive and metastatic potential. Moreover, a negative correlation between MST4 and p-AKT, Snail1, and Ki67 and a positive correlation between MST4 and E-cadherin were determined in clinical HCC samples.

Conclusions: Our findings indicate that MST4 suppresses EMT, invasion, and metastasis of HCC cells by modulating the PI3K/AKT/Snail1 axis, suggesting that MST4 may be a potential prognostic biomarker for aggressive and metastatic HCC.

Syndecan-1 modulates the invasive potential of endometrioma via TGF-β signalling in a subgroup of women with endometriosis

STUDY QUESTION

What is the physiological role of transforming growth factor-beta (TGF-β1) and syndecans (SDC1, SDC4) in endometriotic cells in women with endometriosis?

SUMMARY ANSWER

We observed an abnormal, pro-invasive phenotype in a subgroup of samples with ovarian endometriosis, which was reversed by combining gene silencing of SDC1 with the TGF-β1 treatment.

WHAT IS KNOWN ALREADY

Women with endometriosis express high levels of TGF-β1 and the proteoglycan co-receptors SDC1 and SDC4 within endometriotic cysts. However, how SDC1 and SDC4 expression is regulated by TGF-β1 and the physiological significance of the high expression in endometriotic cysts remains unknown as does the potential role in disease severity.

STUDY DESIGN, SIZE, DURATION

We utilized a pre-validated panel of stem- and cancer cell-associated markers on endometriotic tissue (n = 15) to stratify subgroups of women with endometriosis. Furthermore, CD90+CD73+CD105+ (SC+) endometriotic stromal cells from these patient subgroups were explored for their invasive behaviour in vitro by transient gene inhibition of SDC1 or SDC4, both in the presence or absence of TGF-β1 treatment.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Endometriotic cyst biopsies (n = 15) were obtained from women diagnosed with ovarian endometriosis (ASRM Stage III-IV). Gene expression variability was assessed on tissue samples by applying gene clustering tools for the dataset generated from the pre-validated panel of markers. Three-dimensional (3D) spheroids from endometriotic SC+ were treated in vitro with increasing doses of TGF-β1 or the TGFBRI/II inhibitor Ly2109761 and assessed for SDC1, SDC4 expression and in vitro 3D-spheroid invasion. Transcriptomic signatures from the invaded 3D spheroids were evaluated upon combining transient gene silencing of SDC1 or SDC4, both in presence or absence of TGF-β1 treatment. Furthermore, nanoscale changes on the surface of endometriotic cells were analysed after treatment with TGF-β1 or TGFBRI/II inhibitor using atomic force microscopy.

MAIN RESULTS AND THE ROLE OF CHANCE

Gene clustering analysis revealed that endometriotic tissues displayed variability in their gene expression patterns; a small subgroup of samples (2/15, Endo-hi) exhibited high levels of SDC1, SDC4 and molecules involved in TGF-β signalling (TGF-β1, ESR1, CTNNB1, SNAI1, BMI1). The remaining endometriotic samples (Endo-lo) showed a uniform, low gene expression profile. Three-dimensional spheroids derived from Endo-hi SC+ but not Endo-lo SC+ samples showed an aberrant expression of SDC1 and exhibited enhanced 3D-spheroid invasion in vitro, upon rhTGF-β1 treatment. However, this abnormal, pro-invasive response of Endo-hi SC+ was reversed upon gene silencing of SDC1 with the TGF-β1 treatment. Interestingly, transcriptomic signatures of 3D spheroids silenced for SDC1 and consecutively treated with TGF-β1, showed a down-regulation of cancer-associated pathways such as WNT and GPCR signalling.

LARGE SCALE DATA

Transcriptomic data were deposited in NCBI's Gene Expression Omnibus (GEO) and could be retrieved using GEO series accession number: GSE135122.

LIMITATIONS, REASONS FOR CAUTION

It is estimated that about 2.5% of endometriosis patients have a potential risk for developing ovarian cancer later in life. It is possible that the pro-oncogenic molecular changes observed in this cohort of endometriotic samples may not correlate with clinical occurrence of ovarian cancer later in life, thus a validation will be required.

WIDER IMPLICATIONS OF THE FINDINGS

This study emphasizes the importance of interactions between syndecans and TGF-β1 in the pathophysiology of endometriosis. We believe that this knowledge could be important in order to better understand endometriosis-associated complications such as ovarian cancer or infertility.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Cancerfonden (CAN 2016/696), Radiumhemmets Forskningsfonder (Project no. 154143 and 184033), EU MSCA-RISE-2015 project MOMENDO (691058), Estonian Ministry of Education and Research (IUT34-16), Enterprise Estonia (EU48695) and Karolinska Institute. Authors do not have any conflict of interest.

Critical signaling pathways governing hepatocellular carcinoma behavior; small molecule-based approaches

Hepatocellular carcinoma (HCC) is the second leading cause of death due to cancer. Although there are different treatment options, these strategies are not efficient in terms of restricting the tumor cell's proliferation and metastasis. The liver tumor microenvironment contains the non-parenchymal cells with supportive or inhibitory effects on the cancerous phenotype of HCC. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of liver carcinoma cells. Recent studies have established new approaches for the prevention and treatment of HCC using small molecules. Small molecules are compounds with a low molecular weight that usually inhibit the specific targets in signal transduction pathways. These components can induce cell cycle arrest, apoptosis, block metastasis, and tumor growth. Devising strategies for simultaneously targeting HCC and the non-parenchymal population of the tumor could lead to more relevant research outcomes. These strategies may open new avenues for the treatment of HCC with minimal cytotoxic effects on healthy cells. This study provides the latest findings on critical signaling pathways governing HCC behavior and using small molecules in the control of HCC both in vitro and in vivo models.

A new horizon in risk stratification of hepatocellular carcinoma by integrating vessels that encapsulate tumor clusters and microvascular invasion

BACKGROUND

Vessels that encapsulate tumor clusters (VETC) is a novel described vascular pattern different from microvascular invasion (MVI) for patients with hepatocellular carcinoma (HCC). The prognostic value of integrating VETC and MVI (VETC-MVI model) in HCC patients after resection remains unclear.

METHODS

From January 2013 to December 2016, 498 HCC patients who underwent curative resection were enrolled from five academic centers and stratified into different groups according to their VETC and MVI statuses. Overall survival (OS), disease-free survival (DFS), and early and late recurrence rates were evaluated.

RESULTS

The patients were divided into four subgroups: VETC^-/MVI^- (n = 277, 55.6%), VETC^-/MVI⁺ (n = 110, 22.1%), VETC⁺/MVI^- (n = 53, 10.6%), and VETC⁺/MVI⁺ (n = 58, 11.6%). The patients in the VETC⁺/MVI^- and VETC^-/MVI⁺ groups had similar long-term outcomes (OS: p = 0.402; DFS: p = 0.990), VETC^-/MVI^- patients showed the best prognosis, and VETC⁺/MVI⁺ patients had the worst prognosis. Further analysis revealed that the VETC-MVI model showed a similar stratification ability for early recurrence but not for late recurrence. The area under the curve values for early recurrence was 0.70, 0.63 and 0.64 for the VETC-MVI model, VETC, and MVI, respectively (VETC-MVI model vs VETC: p < 0.001; VETC-MVI model vs MVI: p = 0.004; VETC vs MVI: p = 0.539). Multivariate Cox regression analysis showed that the VETC-MVI model successfully predicted OS, DFS and early recurrence.

CONCLUSIONS

VETC status provides additional discriminative information for patients with either MVI^- or MVI⁺. A combination of VETC and MVI may help classify subtypes and predict the prognosis of HCC patients.

Short overview on the relevance of microRNA-reactive oxygen species (ROS) interactions and lipid peroxidation for modulation of oxidative stress-mediated signalling pathways in cancer treatment

OBJECTIVES

Modulation of oxidative stress-mediated signalling pathways is constantly getting more attention as a valuable therapeutic strategy in cancer treatment. Although complexity of redox signalling pathways might represent a major hurdle, the development of advanced -omics technologies allow thorough studies on cancer-specific biology, which is essential to elucidate the impact of these signalling pathways in cancer cells. The scope of our review is to provide updated information about recent developments in cancer treatment.

KEY FINDINGS

In recent years identifying oxidative stress-mediated signalling pathways is a major goal of cancer research assuming it may provide novel therapeutic approaches through the development of agents that may have better tissue penetration and therefore affect specific redox signalling pathways. In this review, we discuss some recent studies focussed on the modulation of oxidative stress-related signalling pathways as a novel anti-cancer treatment, with a particular emphasis on the induction of lipid peroxidation.

CONCLUSIONS

Characterization and modulation of oxidative stress-mediated signalling pathways and lipid peroxidation products will continue to foster novel interest and further investigations, which may pave the way for more effective, selective, and personalized integrative biomedicine treatment strategies.

Cell surface thermal proteome profiling tracks perturbations and drug targets on the plasma membrane

Numerous drugs and endogenous ligands bind to cell surface receptors leading to modulation of downstream signaling cascades and frequently to adaptation of the plasma membrane proteome. In-depth analysis of dynamic processes at the cell surface is challenging due to biochemical properties and low abundances of plasma membrane proteins. Here we introduce cell surface thermal proteome profiling for the comprehensive characterization of ligand-induced changes in protein abundances and thermal stabilities at the plasma membrane. We demonstrate drug binding to extracellular receptors and transporters, discover stimulation-dependent remodeling of T cell receptor complexes and describe a competition-based approach to measure target engagement of G-protein-coupled receptor antagonists. Remodeling of the plasma membrane proteome in response to treatment with the TGFB receptor inhibitor SB431542 leads to partial internalization of the monocarboxylate transporters MCT1/3 explaining the antimetastatic effects of the drug.

Targeting transforming growth factor-β signaling for enhanced cancer chemotherapy

During the past decades, drugs targeting transforming growth factor-β (TGFβ) signaling have received tremendous attention for late-stage cancer treatment since TGFβ signaling has been recognized as a prime driver for tumor progression and metastasis. Nonetheless, in healthy and pre-malignant tissues, TGFβ functions as a potent tumor suppressor. Furthermore, TGFβ signaling plays a key role in normal development and homeostasis by regulating cell proliferation, differentiation, migration, apoptosis, and immune evasion, and by suppressing tumor-associated inflammation. Therefore, targeting TGFβ signaling for cancer therapy is challenging. Recently, we and others showed that blocking TGFβ signaling increased chemotherapy efficacy, particularly for nanomedicines. In this review, we briefly introduce the TGFβ signaling pathway, and the multifaceted functions of TGFβ signaling in cancer, including regulating the tumor microenvironment (TME) and the behavior of cancer cells. We also summarize TGFβ targeting agents. Then, we highlight TGFβ inhibition strategies to restore the extracellular matrix (ECM), regulate the tumor vasculature, reverse epithelial-mesenchymal transition (EMT), and impair the stemness of cancer stem-like cells (CSCs) to enhance cancer chemotherapy efficacy. Finally, the current challenges and future opportunities in targeting TGFβ signaling for cancer therapy are discussed.

A Pilot Study of Galunisertib plus Stereotactic Body Radiotherapy in Patients with Advanced Hepatocellular Carcinoma

TGFβ is a pleiotropic cytokine with immunosuppressive activity. In preclinical models, blockade of TGFβ enhances the activity of radiation and invokes T-cell antitumor immunity. Here, we combined galunisertib, an oral TGFβ inhibitor, with stereotactic body radiotherapy (SBRT) in patients with advanced hepatocellular carcinoma (HCC) and assessed safety, efficacy, and immunologic correlatives. Patients (n = 15) with advanced HCC who progressed on, were intolerant of, or refused sorafenib were treated with galunisertib (150 mg orally twice a day) on days 1 to 14 of each 28-day cycle. A single dose of SBRT (18-Gy) was delivered between days 15 to 28 of cycle 1. Site of index lesions treated with SBRT included liver (9 patients), lymph node (4 patients), and lung (2 patients). Blood for high-dimensional single cell profiling was collected. The most common treatment-related adverse events were fatigue (53%), abdominal pain (46.6%), nausea (40%), and increased alkaline phosphatase (40%). There were two instances of grade 2 alkaline phosphatase increase and two instances of grade 2 bilirubin increase. One patient developed grade 3 achalasia, possibly related to treatment. Two patients achieved a partial response. Treatment with galunisertib was associated with a decrease in the frequency of activated T regulatory cells in the blood. Distinct peripheral blood leukocyte populations detected at baseline distinguished progressors from nonprogressors. Nonprogressors also had increased CD8⁺PD-1⁺TIGIT⁺ T cells in the blood after treatment. We found galunisertib combined with SBRT to be well tolerated and associated with antitumor activity in patients with HCC. Pre- and posttreatment immune profiling of the blood was able to distinguish patients with progression versus nonprogression.

Proteoglycan-4 is correlated with longer survival in HCC patients and enhances sorafenib and regorafenib effectiveness via CD44 in vitro

Sorafenib and regorafenib administration is among the preferential approaches to treat hepatocellular carcinoma (HCC), but does not provide satisfactory benefits. Intensive crosstalk occurring between cancer cells and other multiple non-cancerous cell subsets present in the surrounding microenvironment is assumed to affect tumor progression. This interplay is mediated by a number of soluble and structural extracellular matrix (ECM) proteins enriching the stromal milieu. Here we assess the HCC tumor expression of the ECM protein proteoglycan 4 (PRG4) and its potential pharmacologic activity either alone, or in combination with sorafenib and regorafenib. PRG4 mRNA levels resulted strongly correlated with increased survival rate of HCC patients (p = 0.000) in a prospective study involving 78 HCC subjects. We next showed that transforming growth factor beta stimulates PRG4 expression and secretion by primary human HCC cancer-associated fibroblasts, non-invasive HCC cell lines, and ex vivo specimens. By functional tests we found that recombinant human PRG4 (rhPRG4) impairs HCC cell migration. More importantly, the treatment of HCC cells expressing CD44 (the main PRG4 receptor) with rhPRG4 dramatically enhances the growth-limiting capacity of sorafenib and regorafenib, whereas not significantly affecting cell proliferation per se. Conversely, rhPRG4 only poorly potentiates drug effectiveness on low CD44-expressing or stably CD44-silenced HCC cells. Overall, these data suggest that the physiologically-produced compound PRG4 may function as a novel tumor-suppressive agent by strengthening sorafenib and regorafenib effects in the treatment of HCC.

A Phase 2 Study of Galunisertib (TGF-β1 Receptor Type I Inhibitor) and Sorafenib in Patients With Advanced Hepatocellular Carcinoma

Inhibition of tumor growth factor-β (TGF-β) receptor type I potentiated the activity of sorafenib in preclinical models of hepatocellular carcinoma (HCC). Galunisertib is a small-molecule selective inhibitor of TGF-β1 receptor type I, which demonstrated activity in a phase 2 trial as second-line HCC treatment.

Effects of Pyrrole-Imidazole Polyamides Targeting Human TGF-β1 on the Malignant Phenotypes of Liver Cancer Cells

Synthetic pyrrole-imidazole (PI) polyamides bind to the minor groove of double-helical DNA with high affinity and specificity, and inhibit the transcription of corresponding genes. In liver cancer, transforming growth factor (TGF)-β expression is correlated with tumor grade, and high-grade liver cancer tissues express epithelial-mesenchymal transition markers. TGF-β1 was reported to be involved in cancer development by transforming precancer cells to cancer stem cells (CSCs). This study aimed to evaluate the effects of TGF-β1-targeting PI polyamide on the growth of liver cancer cells and CSCs and their TGF-β1 expression. We analyzed TGF-β1 expression level after the administration of GB1101, a PI polyamide that targets human TGF-β1 promoter, and examined its effects on cell proliferation, invasiveness, and TGF-β1 mRNA expression level. GB1101 treatment dose-dependently decreased TGF-β1 mRNA levels in HepG2 and HLF cells, and inhibited HepG2 colony formation associated with downregulation of TGF-β1 mRNA. Although GB1101 did not substantially inhibit the proliferation of HepG2 cells compared to untreated control cells, GB1101 significantly suppressed the invasion of HLF cells, which displayed high expression of CD44, a marker for CSCs. Furthermore, GB1101 significantly inhibited HLF cell sphere formation by inhibiting TGF-β1 expression, in addition to suppressing the proliferation of HLE and HLF cells. Taken together, GB1101 reduced TGF-β1 expression in liver cancer cells and suppressed cell invasion; therefore, GB1101 is a novel candidate drug for the treatment of liver cancer.

Biomarkers and overall survival in patients with advanced hepatocellular carcinoma treated with TGF-βRI inhibitor galunisertib

Background

Transforming growth factor beta (TGF-β) signalling is involved in the development of hepatocellular carcinoma (HCC). We followed changes in biomarkers during treatment of patients with HCC with the TGF-βRI/ALK5 inhibitor galunisertib.

Methods

This phase 2 study (NCT01246986) enrolled second-line patients with advanced HCC into one of two cohorts of baseline serum alpha-fetoprotein (AFP): Part A (AFP ≥1.5x ULN) or Part B (AFP <1.5x ULN). Baseline and postbaseline levels of AFP, TGF-β1, E-cadherin, selected miRNAs, and other plasma proteins were monitored.

Results

The study enrolled 149 patients (Part A, 109; Part B, 40). Median OS was 7.3 months in Part A and 16.8 months in Part B. Baseline AFP, TGF-β1, E-cadherin, and an additional 16 plasma proteins (such as M-CSF, IL-6, ErbB3, ANG-2, neuropilin-1, MIP-3 alpha, KIM-1, uPA, IL-8, TIMP-1, ICAM-1, Apo A-1, CA-125, osteopontin, tetranectin, and IGFBP-1) were found to correlate with OS. In addition, a range of miRs were found to be associated with OS. In AFP responders (21% of patients in Part A with decrease of >20% from baseline) versus non-responders, median OS was 21.5 months versus 6.8 months (p = 0.0015). In TGF-β1 responders (51% of all patients) versus non-responders, median OS was 11.2 months versus 5.3 months (p = 0.0036).

Conclusions

Consistent with previous findings, both baseline levels and changes from baseline of circulating AFP and TGF-β1 function as prognostic indicators of survival. Future trials are needed to confirm and extend these results.

Utilizing Experimental Mouse Model to Identify Effectors of Hepatocellular Carcinoma Induced by HBx Antigen

Hepatocellular carcinoma (HCC) is among the ten most commonly diagnosed cancers and the fourth leading cause of cancer-related death. Patients with hepatitis B virus (HBV) infection are prone to developing chronic liver diseases (i.e., fibrosis and cirrhosis), and the HBV X antigen plays an important role in the development of HCC. The difficulty in detecting HCC at the early stages is one of the main reasons that the death rate approximates the incidence rate. The regulators controlling the downstream liver protein expression from HBV infection are unclear. Mass spectrometric techniques and customized programs were used to identify differentially expressed proteins which may be involved in the development of liver fibrosis and HCC progression in hepatitis B virus X protein transgenic mice (HBx mice). FSTL1, CTSB, and TGF-β enhanced the signaling pathway proteins during the pathogenesis of HBx. Missing proteins can be essential in cell growth, differentiation, apoptosis, migration, metastasis or angiogenesis. We found that LHX2, BMP-5 and GDF11 had complex interactions with other missing proteins and BMP-5 had both tumor suppressing and tumorigenic roles. BMP-5 may be involved in fibrosis and tumorigenic processes in the liver. These results provide us an understanding of the mechanism of HBx-induced disorders, and may serve as molecular targets for liver treatment.

New landscapes and horizons in hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC), is the sixth most frequent form of cancer and leads to the fourth highest number of deaths each year. HCC results from a combination of environmental factors and aging as there are driver mutations at oncogenes which occur during aging. Most of HCCs are diagnosed at advanced stage preventing curative therapies. Treatment in advanced stage is a challenging and pressing problem, and novel and well-tolerated therapies are urgently needed. We will discuss further advances beyond sorafenib that target additional signaling pathways and immune checkpoint proteins. The scenario of possible systemic therapies for patients with advanced HCC has changed dramatically in recent years. Personalized genomics and various other omics approaches may identify actionable biochemical targets, which are activated in individual patients, which may enhance therapeutic outcomes. Further studies are needed to identify predictive biomarkers and aberrantly activated signaling pathways capable of guiding the clinician in choosing the most appropriate therapy for the individual patient.

Self-Renewal Signalling Pathway Inhibitors: Perspectives on Therapeutic Approaches for Cancer Stem Cells

The poor survival and prognosis of individuals with cancer are often attributed to tumour relapse and metastasis, which may be due to the presence of cancer stem cells (CSCs). CSCs have the characteristics of self-renewal, differentiation potential, high carcinogenicity, and drug resistance. In addition, CSCs exhibit many characteristics similar to those of embryonic or tissue stem cells while displaying persistent abnormal activation of self-renewal pathways associated with development and tissue homeostasis, including the Wnt, Notch, Hedgehog (Hh), TGF-β, JAK/STAT3, and NF-κB pathways. Therefore, we can eliminate CSCs by targeting these self-renewal pathways to constrain stem cell replication, survival and differentiation. At the same time, we cannot neglect the ping-pong effect of the tumour microenvironment, which releases cytokines and promotes self-renewal pathways in CSCs. Recently, meaningful progress has been made in the study of inhibitors of self-renewal pathways in tumours. This review primarily summarizes several representative and novel agents targeting these self-renewal signalling pathways and the tumour microenvironment and that represent a promising strategy for treating refractory and recurrent cancer.

Active PLK1-driven metastasis is amplified by TGF-β signaling that forms a positive feedback loop in non-small cell lung cancer

Early findings that PLK1 is highly expressed in cancer have driven an exploration of its functions in metastasis. However, whether PLK1 induces metastasis in vivo and its underlying mechanisms in NSCLC have not yet been determined. Here, we show that the expression of active PLK1 phosphorylated at T210, abundant in TGF-β-treated lung cells, potently induced metastasis in a tail-vein injection model. Active PLK1 with intact polo-box and ATP-binding domains accelerated cell motility and invasiveness by triggering EMT reprogramming, whereas a phosphomimetic version of p-S137-PLK1 did not, indicating that the phosphorylation status of PLK1 may determine the cell traits. Active PLK1-driven invasiveness upregulated TGF-β signaling and TSG6 encoded by TNFAIP6. Loss of TNFAIP6 disturbed the metastatic activity induced by active PLK1 or TGF-β. Clinical relevance shows that PLK1 and TNFAIP6 are strong predictors of poor survival rates in metastatic NSCLC patients. Therefore, we suggest that active PLK1 promotes metastasis by upregulating TGF-β signaling, which amplifies its metastatic properties by forming a positive feedback loop and that the PLK1/TGF-β-driven metastasis is effectively blocked by targeting PLK1 and TSG6, providing PLK1 and TSG6 as negative markers for prognostics and therapeutic targets in metastatic NSCLC.

CCL7 Signaling in the Tumor Microenvironment

The tumor microenvironment is the primary location in which tumor cells and the host immune system interact. There are many physiological, biochemical, cellular mechanisms in the neighbor of tumor which is composed of various cell types. Interactions of chemokines and chemokine receptors can recruit immune cell subsets into the tumor microenvironment. These interactions can modulate tumor progression and metastasis. In this chapter, we will focus on chemokine (C-C motif) ligand 7 (CCL7) that is highly expressed in the tumor microenvironment of various cancers, including colorectal cancer, breast cancer, oral cancer, renal cancer, and gastric cancer. We reviewed how CCL7 can affect cancer immunity and tumorigenesis by describing its regulation and roles in immune cell recruitment and stromal cell biology.

Tankyrases/β-catenin Signaling Pathway as an Anti-proliferation and Anti-metastatic Target in Hepatocarcinoma Cell Lines

Objective: The Wnt/β-catenin pathway is involved in the development of hepatocellular carcinoma (HCC) and malignant events such as the epithelial-mesenchymal transition (EMT), metastasis, and invasion. Studies have illustrated that the inhibition of tankyrases (TNKS) antagonizes Wnt/β-catenin signaling in many cancer cells. Methods: The expression levels of proteins related to the Wnt/β-catenin pathway and EMT were analyzed by immunohistochemistry in HCC tissue and paired adjacent normal tissue (n = 10), and in an analysis of The Cancer Genome Atlas (TCGA) data. Additionally, after treatment of HCC cell lines with TNKS1/2 small interfering RNA (siRNA) and a novel TNKS inhibitor (NVP-TNKS656), cell viability, cell clone formation, wound-healing, and cell invasion assays were performed. Results: Higher expression of β-catenin, TNKS, vimentin, and N-cadherin was observed in HCC tissue compared to adjacent normal tissue, but lower expression of E-cadherin was found in HCC tissue. These findings were also observed in the TCGA analysis. In addition, TNKS inhibition (using TNKS1/2 siRNA and NVP-TNKS656) not only abrogated the proliferation of the HCC cell lines but also suppressed metastasis, invasion, and EMT phenotypic features. Moreover, the mechanisms related to TNKS inhibition in HCC probably involved the stabilization of AXIN levels and the downregulation of β-catenin, which mediates EMT marker expression. Conclusion: The TNKS/β-catenin signaling pathway is a potential anti-proliferation and anti-metastatic target in HCC.

Sanguinarine inhibits epithelial-mesenchymal transition via targeting HIF-1α/TGF-β feed-forward loop in hepatocellular carcinoma

Epithelial–mesenchymal transition (EMT) plays a crucial role in hepatocellular carcinoma (HCC) progression. Hypoxia and excessive transforming growth factor-β (TGF-β) have been identified as inducers and target for EMT in HCC. Here, we show hypoxia inducible factor-1α (HIF-1α) and TGF-β form a feed-forward loop to induce EMT in HCC cells. Further mechanistic study indicates under both hypoxia and TGF-β stimulation, Smad and PI3K-AKT pathways are activated. We show sanguinarine, a natural benzophenanthridine alkaloid, impairs the proliferation of nine kinds of HCC cell lines and the colony formation of HCC cells. In hypoxic and TGF-β cell models, sanguinarine inhibits HIF-1α signaling and the expression of EMT markers, translocation of Snail and activation of both Smad and PI3K-AKT pathways. Sanguinarine could also inhibit TGF-β-induced cell migration in HCC cells. In vivo studies reveal that the administration of sanguinarine inhibits tumor growth and HIF-1α signaling, inhibits the expression changes of EMT markers as well as Smad and PI3K-AKT pathway proteins. Our findings suggest that sanguinarine is a promising candidate targeting HIF-1α/TGF-β signaling to improve the treatment for HCC patients.

DKK1 promotes hepatocellular carcinoma inflammation, migration and invasion: Implication of TGF-β1

Dickkopf-1 (DKK1), an inhibitor of the most frequently impaired signaling pathway in hepatocellular carcinoma (HCC), the Wnt/beta-catenin pathway, seems to fulfill contradictory functions in the process of tumorigenesis, acting either as an oncogenic promoter of metastasis or as a tumor suppressor. Elevated serum levels of DKK1 have been reported in HCC; however, little is known about its functional significance. In the current study, we treated HepG2/C3A and PLC/PRF/5 with the recombinant protein DKK1. Cytotoxicity was first determined by the WST-8 assay. AFP expression was measured at both the mRNA and protein levels. Expression of the oncogenes MYC, CCND1, hTERT, and MDM2 and the tumor suppressor genes TP53, P21 and RB was assessed. Western blot analysis of non-phosphorylated ẞ-catenin and Sanger sequencing were performed to explain the functional differences between the two cell lines. Subsequently, inflammation, migration and invasion were evaluated by qPCR, ELISA, the Boyden chamber assay, zymography, and MMP-2 and MMP-9 western blot analysis. Knockdown of DKK1 and TGF-β1 were also performed. Our results suggest that DKK1 exerts an oncogenic effect on HepG2/C3A cell line by upregulating the expression of oncogenes and downregulating that of tumor suppressor genes, whereas the opposite effect was demonstrated in PLC/PRF/5 cells. This differential impact of DKK1 can be explained by the mutations that affect the canonical Wnt pathway that were detected in exon 3 of the CTNNB1 gene in the HepG2 cell line. We further confirmed that DKK1 promotes inflammation, tumor invasion and migration in both cell types. The canonical pathway was not responsible for the DKK1 proinvasive effect, as indicated by the active ẞ-catenin levels in the two cell lines upon DKK1 treatment. Interestingly, knockdown of TGF-β1 negatively affected the DKK1 proinvasive effect. Taken together, DKK1 appears to facilitate tumor invasion and migration through TGF- β1 by remodeling the tumor microenvironment and inducing inflammation. This finding endorses the relevance of TGF-β1 as a therapeutic target.

The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges

Epithelial-to-Mesenchymal Transition (EMT) has been shown to be crucial in tumorigenesis where the EMT program enhances metastasis, chemoresistance and tumor stemness. Due to its emerging role as a pivotal driver of tumorigenesis, targeting EMT is of great therapeutic interest in counteracting metastasis and chemoresistance in cancer patients. The hallmark of EMT is the upregulation of N-cadherin followed by the downregulation of E-cadherin, and this process is regulated by a complex network of signaling pathways and transcription factors. In this review, we summarized the recent understanding of the roles of E- and N-cadherins in cancer invasion and metastasis as well as the crosstalk with other signaling pathways involved in EMT. We also highlighted a few natural compounds with potential anti-EMT property and outlined the future directions in the development of novel intervention in human cancer treatments. We have reviewed 287 published papers related to this topic and identified some of the challenges faced in translating the discovery work from bench to bedside.

Molecular mechanisms of circular RNAs, transforming growth factor-β, and long noncoding RNAs in hepatocellular carcinoma

At the heart of hepatocellular carcinoma (HCC) lies disruption of signaling pathways at the level of molecules, genes, and cells. Non‐coding RNAs (ncRNAs) have been implicated in the disease progression of HCC. For instance, dysregulated expression of circular RNAs (circRNAs) has been observed in patients with HCC. As such, these RNAs are potential therapeutic targets and diagnostic markers for HCC. Long non‐coding RNAs (lncRNAs), a type of ncRNA, have also been recognized to participate in the initiation and progression of HCC. Transforming growth factor‐beta (TGF‐β) is another element which is now recognized to play crucial roles in HCC. It has been implicated in many biological processes such as survival, immune surveillance, and cell proliferation. In HCC, TGF‐β promotes disease progression by two mechanisms: an intrinsic signaling pathway and the extrinsic pathway. Through these pathways, it modulates various microenvironment factors such as inflammatory mediators and fibroblasts. An interesting yet‐to‐be resolved concept is whether the HCC‐promoting role of TGF‐β pathways is limited to a subset of HCC patients or it is involved in the whole process of HCC development. This review summarizes recent advancements to highlight the roles of circRNAs, lncRNAs, and TGF‐β in HCC.

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.

Small molecule inhibitors of epithelial-mesenchymal transition for the treatment of cancer and fibrosis

Tissue fibrosis and cancer both lead to high morbidity and mortality worldwide; thus, effective therapeutic strategies are urgently needed. Because drug resistance has been widely reported in fibrotic tissue and cancer, developing a strategy to discover novel targets for targeted drug intervention is necessary for the effective treatment of fibrosis and cancer. Although many factors lead to fibrosis and cancer, pathophysiological analysis has demonstrated that tissue fibrosis and cancer share a common process of epithelial-mesenchymal transition (EMT). EMT is associated with many mediators, including transcription factors (Snail, zinc-finger E-box-binding protein and signal transducer and activator of transcription 3), signaling pathways (transforming growth factor-β1, RAC-α serine/threonine-protein kinase, Wnt, nuclear factor-kappa B, peroxisome proliferator-activated receptor, Notch, and RAS), RNA-binding proteins (ESRP1 and ESRP2) and microRNAs. Therefore, drugs targeting EMT may be a promising therapy against both fibrosis and tumors. A large number of compounds that are synthesized or derived from natural products and their derivatives suppress the EMT by targeting these mediators in fibrosis and cancer. By targeting EMT, these compounds exhibited anticancer effects in multiple cancer types, and some of them also showed antifibrotic effects. Therefore, drugs targeting EMT not only have both antifibrotic and anticancer effects but also exert effective therapeutic effects on multiorgan fibrosis and cancer, which provides effective therapy against fibrosis and cancer. Taken together, the results highlighted in this review provide new concepts for discovering new antifibrotic and antitumor drugs.

Prognostic and Therapeutic Implications of Microvascular Invasion in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a morbid condition for which surgical and ablative therapy are the only options for cure. Nonetheless, over half of patients treated with an R0 resection will develop recurrence. Early recurrences within 2 years after resection are thought to be due to the presence of residual microscopic disease, while late recurrences > 2 years after resection are thought to be de novo metachronous HCCs arising in chronically injured liver tissue. Microvascular invasion (MVI) is defined as the presence of micrometastatic HCC emboli within the vessels of the liver, and is a critical determinant of early recurrence and survival. In this review, we summarize the pathogenesis and clinical relevance of MVI, which correlates with adverse biological features, including high grade, large tumor size, and epithelial-mesenchymal transition. Multiple classification schemas have been proposed to capture the heterogeneous features of MVI that are associated with prognosis. However, currently, MVI can only be determined based on surgical specimens, limiting its clinical applicability. Going forward, advances in axial imaging technologies, molecular characterization of biopsy tissue, and novel serum biomarkers hold promise as future methods for non-invasive MVI detection. Ultimately, MVI status may be used to help clinicians determine treatment plans, particularly with respect to surgical intervention, and to provide more accurate prognostication.

Perspectives of small molecule inhibitors of activin receptor‑like kinase in anti‑tumor treatment and stem cell differentiation (Review)

Activin receptor‑like kinases (ALKs), members of the type I activin receptor family, belong to the serine/threonine kinase receptors of the transforming growth factor‑β (TGF‑β) superfamily. ALKs mediate the roles of activin/TGF‑β in a wide variety of physiological and pathological processes, ranging from cell differentiation and proliferation to apoptosis. For example, the activities of ALKs are associated with an advanced tumor stage in prostate cancer and the chondrogenic differentiation of mesenchymal stem cells. Therefore, potent and selective small molecule inhibitors of ALKs would not only aid in investigating the function of activin/TGF‑β, but also in developing treatments for these diseases via the disruption of activin/TGF‑β. In recent studies, several ALK inhibitors, including LY‑2157299, SB‑431542 and A‑83‑01, have been identified and have been confirmed to affect stem cell differentiation and tumor progression in animal models. This review discusses the therapeutic perspective of small molecule inhibitors of ALKs as drug targets in tumor and stem cells.

Suppressing growth and invasion of human hepatocellular carcinoma cells by celecoxib through inhibition of cyclooxygenase-2

Purpose: Biomarkers are lacking in hepatocellular carcinoma (HCC). Cyclooxygenase-2 (COX-2) and its metabolites play crucial roles in the process of inflammation-tumor transformation. This study was aimed to detect COX-2 expression in HCC tissues and evaluate the effects of a COX-2 inhibitor, celecoxib, on biological behaviors of HCC cell lines in vitro.

Methods: COX-2 expression was detected by immunohistochemistry on a human HCC tissue microarray. The correlations of COX-2 expression with tumor clinicopathological variables and overall survival were analyzed. The proliferation, apoptosis, cell cycle distribution, invasion capacity, and related signaling molecules of HCC cells after incubated with COX-2 inhibitor celecoxib were evaluated in vitro.

Results: Expression levels of COX-2 in HCC tissues were significantly higher than those in paracancerous tissues. The TNM stage III-IV, tumor size >5 cm, lymphovascular invasion and distant metastasis was higher in high COX-2 expression group compared with that in low COX-2 expression group. Patients with low COX-2 expression achieved better 5-year overall survival than those with high COX-2 expression. Treatment with celecoxib was sufficient to inhibit cell proliferation, promote apoptosis, and induce G0/G1 cell cycle arrest in HCC cells with concentration- and time-dependent manners. Celecoxib up-regulated E-cadherin protein through inhibiting COX-2-prostaglandin E2 (PGE2)-PGE2 receptor 2 (EP2)-p-Akt/p-ERK signaling pathway to suppress HCC cells migration and invasion.

Conclusion: High COX-2 expression was associated with advanced TNM stage, larger tumor size, increased lymphovascular invasion and short survival. Targeting inhibition of COX-2 by celecoxib exhibited anti-tumor activities by suppressing proliferation, promoting apoptosis, and inhibiting the aggressive properties of HCC cells.