Differential Inhibition of the TGF-β Signaling Pathway in HCC Cells Using the Small Molecule Inhibitor LY2157299 and the D10 Monoclonal Antibody against TGF-β Receptor Type II

MLK3 promotes prooncogenic signaling in hepatocellular carcinoma via TGFβ pathway

Advanced hepatocellular carcinoma (HCC) is a lethal disease, with limited therapeutic options. Mixed Lineage Kinase 3 (MLK3) is a key regulator of liver diseases, although its role in HCC remains unclear. Analysis of TCGA databases suggested elevated MAP3K11 (MLK3 gene) expression, and TMA studies showed higher MLK3 activation in human HCCs. To understand MLK3's role in HCC, we utlized carcinogen-induced HCC model and compared between wild-type and MLK3 knockout (MLK3-/-) mice. Our studies showed that MLK3 kinase activity is upregulated in HCC, and MLK3 deficiency alleviates HCC progression. MLK3 deficiency reduced proliferation in vivo and MLK3 inhibition reduced proliferation and colony formation in vitro. To obtain further insight into the mechanism and identify newer targets mediating MLK3-induced HCCs, RNA-sequencing analysis was performed. These showed that MLK3 deficiency modulates various gene signatures, including EMT, and reduces TGFB1&2 expressions. HCC cells overexpressing MLK3 promoted EMT via autocrine TGFβ signaling. Moreover, MLK3 deficiency attenuated activated hepatic stellate cell (HSC) signature, which is increased in wild-type. Interestingly, MLK3 promotes HSC activation via paracrine TGFβ signaling. These findings reveal TGFβ playing a key role at different steps of HCC, downstream of MLK3, implying MLK3-TGFβ axis to be an ideal drug target for advanced HCC management.

Inhibition of transforming growth factor-β signals suppresses tumor formation by regulation of tumor microenvironment networks

The tumor microenvironment (TME) consists of cancer cells surrounded by stromal components including tumor vessels. Transforming growth factor-β (TGF-β) promotes tumor progression by inducing epithelial-mesenchymal transition (EMT) in cancer cells and stimulating tumor angiogenesis in the tumor stroma. We previously developed an Fc chimeric TGF-β receptor containing both TGF-β type I (TβRI) and type II (TβRII) receptors (TβRI-TβRII-Fc), which trapped all TGF-β isoforms and suppressed tumor growth. However, the precise mechanisms underlying this action have not yet been elucidated. In the present study, we showed that the recombinant TβRI-TβRII-Fc protein effectively suppressed in vitro EMT of oral cancer cells and in vivo tumor growth in a human oral cancer cell xenograft mouse model. Tumor cell proliferation and angiogenesis were suppressed in tumors treated with TβRI-TβRII-Fc. Molecular profiling of human cancer cells and mouse stroma revealed that K-Ras signaling and angiogenesis were suppressed. Administration of TβRI-TβRII-Fc protein decreased the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF), interleukin-1β (IL-1β) and epiregulin (EREG) in the TME of oral cancer tumor xenografts. HB-EGF increased proliferation of human oral cancer cells and mouse endothelial cells by activating ERK1/2 phosphorylation. HB-EGF also promoted oral cancer cell-derived tumor formation by enhancing cancer cell proliferation and tumor angiogenesis. In addition, increased expressions of IL-1β and EREG in oral cancer cells significantly enhanced tumor formation. These results suggest that TGF-β signaling in the TME controls cancer cell proliferation and angiogenesis by activating HB-EGF/IL-1β/EREG pathways and that TβRI-TβRII-Fc protein is a promising tool for targeting the TME networks.

Perfluorotributylamine-Loaded Albumin Nanoparticles Downregulate Platelet-Derived TGFβ to Inhibit Tumor Metastasis

Tumor metastasis contributes to the low overall survival of tumor patients, while transforming growth factor-β (TGFβ) has been recognized as a prominently promoting factor in the development of tumor metastasis. Platelets reserve abundant TGFβ, which will be secreted to peripheral blood after activation, and they are the dominant source of circulating TGFβ. Therefore, downregulation of platelet-derived TGFβ is expected to inhibit the metastasis of circulating tumor cells. Here, unfolded human serum albumin (HSA)-coated perfluorotributylamine (PFTBA) nanoparticles were constructed to display a favorable platelet delivery and an antiplatelet effect to downregulate platelet-derived TGFβ in vitro and in blood plasma. PFTBA@HSA-mediated TGFβ downregulation impaired epithelial-mesenchymal transition of tumor cells as well as their migration and invasion behaviors and enhanced immune surveillance of NK cells. Intravenous injection of PFTBA@HSA effectively reduced tumor metastasis on the lungs or liver to improve the survival rate of mice on multiple metastatic models, including CT26 colon cancer, B16F10 melanoma, and 4T1 breast cancer. Compared with the clinical antiplatelet drug ticagrelor, PFTBA@HSA reduced bleeding risk when displaying a favorable downregulation on platelet-derived TGFβ, thereby obtaining a higher therapy benefit. Together, this study confirmed that downregulation of platelet-derived TGFβ by PFTBA@HSA will be a potential approach and therapeutic candidate for the prevention of tumor metastasis.

TGF-β Signaling in Progression of Oral Cancer

Oral cancer is a common malignancy worldwide, accounting for 1.9% to 3.5% of all malignant tumors. Transforming growth factor β (TGF-β), as one of the most important cytokines, is found to play complex and crucial roles in oral cancers. It may act in a pro-tumorigenic and tumor-suppressive manner; activities of the former include cell cycle progression inhibition, tumor microenvironment preparation, apoptosis promotion, stimulation of cancer cell invasion and metastasis, and suppression of immune surveillance. However, the triggering mechanisms of these distinct actions remain unclear. This review summarizes the molecular mechanisms of TGF-β signal transduction, focusing on oral squamous cell and salivary adenoid systemic carcinomas as well as keratocystic odontogenic tumors. Both the supporting and contrary evidence of the roles of TGF-β is discussed. Importantly, the TGF-β pathway has been the target of new drugs developed in the past decade, some having demonstrated promising therapeutic effects in clinical trials. Therefore, the achievements of TGF-β pathway-based therapeutics and their challenges are also assessed. The summarization and discussion of the updated knowledge of TGF-β signaling pathways will provide insight into the design of new strategies for oral cancer treatment, leading to an improvement in oral cancer outcomes.

Ecoevolutionary biology of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC), the most common histological subtype of pancreatic cancer, is an aggressive disease predicted to be the 2nd cause of cancer mortality in the US by 2040. While first-line therapy has improved, 5-year overall survival has only increased from 5 to ∼10%, and surgical resection is only available for ∼20% of patients as most present with advanced disease, which is invariably lethal. PDAC has well-established highly recurrent mutations in four driver genes including KRAS, TP53, CDKN2A, and SMAD4. Unfortunately, these genetic drivers are not currently therapeutically actionable. Despite extensive sequencing efforts, few additional significantly recurrent and druggable drivers have been identified. In the absence of targetable mutations, chemotherapy remains the mainstay of treatment for most patients. Further, the role of the above driver mutations on PDAC initiation and early development is well-established. However, these mutations alone cannot account for PDAC heterogeneity nor discern early from advanced disease. Taken together, management of PDAC is an example highlighting the shortcomings of the current precision medicine paradigm. PDAC, like other malignancies, represents an ecoevolutionary process. Better understanding the disease through this lens can facilitate the development of novel therapeutic strategies to better control and cure PDAC. This review aims to integrate the current understanding of PDAC pathobiology into an ecoevolutionary framework.

Radiosensitizing effect of galunisertib, a TGF-ß receptor I inhibitor, on head and neck squamous cell carcinoma in vitro

Background. Resistance to radiation therapy poses a major clinical problem for patients suffering from head and neck squamous cell carcinoma (HNSCC). Transforming growth factor ß (TGF-ß) has emerged as a potential target. This study aimed to investigate the radiosensitizing effect of galunisertib, a small molecule TGF-ß receptor kinase I inhibitor, on HNSCC cells in vitro. Methods. Three HNSCC cell lines were treated with galunisertib alone, or in combination with radiation. Of those three cell lines, one has a known inactivating mutation of the TGF-ß pathway (Cal27), one has a TGF-ß pathway deficiency (FaDu) and one has no known alteration (SCC-25). The effect on metabolic activity was evaluated by a resazurin-based reduction assay. Cell migration was evaluated by wound-healing assay, clonogenic survival by colony formation assay and cell cycle by FACS analysis. Results. Galunisertib reduced metabolic activity in FaDu, increased in SCC-25 and had no effect on CAL27. Migration was significantly reduced by galunisertib in all three cell lines and showed additive effects in combination with radiation in CAL27 and SCC-25. Colony-forming capabilities were reduced in SCC-25 by galunisertib and also showed an additive effect with adjuvant radiation treatment. Cell cycle analysis showed a reduction of cells in G₁ phase in response to galunisertib treatment. Conclusion. Our results indicate a potential antineoplastic effect of galunisertib in HNSCC with intact TGF-ß signaling in combination with radiation.

[PCR analysis of the expression of chromosome 18 genes in human liver tissue: interindividual variability]

Using human chromosome 18 (Ch18) genes as an example, a PCR analysis of the interindividual variability of gene expression in liver tissue was performed. Although the quantitative profiles of the Ch18 transcriptome, expressed in the number of cDNA copies per single cell, showed a high degree of correlation between donors (Pearson correlation coefficients ranged from 0.963 to 0.966), the expression of the significant number of genes (from 13% to 19%, depending on the method of experimental data normalization) varied by more than 4-fold when comparing donors pairwise. At the same time, the proportion of differentially expressed genes increased with a decrease in the level of their expression. It is shown that the higher quantitative variability of low-abundance transcripts is mainly not technical, but biological. Bioinformatic analysis of the interindividual variability of the differential expression of chromosome 18 genes in human liver tissue did not reveal any statistically significant groups of genes related to certain biological processes that indicated a rather transient nature of the interindividual variability of their expression, probably reflecting the response of cells of an individual to specific external stimuli.

Serine-Threonine Kinase inhibition as antifibrotic therapy: TGF-β and ROCK inhibitors

Serine-threonine kinases mediate the phosphorylation of intracellular protein targets, transferring a phosphorus group from an ATP molecule to the specific amino acid residues within the target proteins. Serine-threonine kinases regulate multiple key cellular functions. From this large group of kinases, transforming growth factor beta (TGF-β) through the serine-threonine activity of its receptors and Rho kinase (ROCK) play an important role in the development and maintenance of fibrosis in various human diseases, including systemic sclerosis. In recent years, multiple drugs targeting and inhibiting these kinases, have been developed, opening the possibility of becoming potential antifibrotic agents of clinical value for treating fibrotic diseases. This review analyzes the contribution of TGF- β and ROCK-mediated serine-threonine kinase molecular pathways to the development and maintenance of pathological fibrosis and the potential clinical use of their inhibition.

The TGF-β Pathway: A Pharmacological Target in Hepatocellular Carcinoma?

Transforming Growth Factor-beta (TGF-β) superfamily members are essential for tissue homeostasis and consequently, dysregulation of their signaling pathways contributes to the development of human diseases. In the liver, TGF-β signaling participates in all the stages of disease progression from initial liver injury to hepatocellular carcinoma (HCC). During liver carcinogenesis, TGF-β plays a dual role on the malignant cell, behaving as a suppressor factor at early stages, but contributing to later tumor progression once cells escape from its cytostatic effects. Moreover, TGF-β can modulate the response of the cells forming the tumor microenvironment that may also contribute to HCC progression, and drive immune evasion of cancer cells. Thus, targeting the TGF-β pathway may constitute an effective therapeutic option for HCC treatment. However, it is crucial to identify biomarkers that allow to predict the response of the tumors and appropriately select the patients that could benefit from TGF-β inhibitory therapies. Here we review the functions of TGF-β on HCC malignant and tumor microenvironment cells, and the current strategies targeting TGF-β signaling for cancer therapy. We also summarize the clinical impact of TGF-β inhibitors in HCC patients and provide a perspective on its future use alone or in combinatorial strategies for HCC treatment.

Reprogramming the anti-tumor immune response via CRISPR genetic and epigenetic editing

Precise clustered regularly interspaced short palindromic repeats (CRISPR)-mediated genetic and epigenetic manipulation of the immune response has become a promising immunotherapeutic approach toward combating tumorigenesis and tumor progression. CRISPR-based immunologic reprograming in cancer therapy comprises the locus-specific enhancement of host immunity, the improvement of tumor immunogenicity, and the suppression of tumor immunoevasion. To date, the ex vivo re-engineering of immune cells directed to inhibit the expression of immune checkpoints or to express synthetic immune receptors (chimeric antigen receptor therapy) has shown success in some settings, such as in the treatment of melanoma, lymphoma, liver, and lung cancer. However, advancements in nuclease-deactivated CRISPR-associated nuclease-9 (dCas9)-mediated transcriptional activation or repression and Cas13-directed gene suppression present novel avenues for the development of tumor immunotherapies. In this review, the basis for development, mechanism of action, and outcomes from recently published Cas9-based clinical trial (genetic editing) and dCas9/Cas13-based pre-clinical (epigenetic editing) data are discussed. Lastly, we review cancer immunotherapy-specific considerations and barriers surrounding use of these approaches in the clinic.

Phase 1b study of galunisertib and ramucirumab in patients with advanced hepatocellular carcinoma

BACKGROUND

Preclinical data suggest that vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β signaling interact to stimulate angiogenesis and suppress antitumor immune responses. Thus, combined inhibition of both pathways may offer greater antitumor activity compared with VEGF-targeted antiangiogenic monotherapy against hepatocellular carcinoma (HCC).

METHODS

This is a multicenter, open-label, phase 1b study of galunisertib, an inhibitor of TGF-β receptor 1, and ramucirumab, an anti-VEGF receptor 2 antibody, in patients with advanced HCC aiming to define the maximum tolerated dose (MTD). Secondary objectives included safety, pharmacokinetics (PK), antitumor efficacy, and plasma alpha-fetoprotein and TGF-β kinetics. Dose escalation employed a 3 + 3 design. Patients received galunisertib at 80 mg (cohort 1) or 150 mg (cohort 2) orally twice a day on days 1-14 of a 28-day cycle combined with ramucirumab 8 mg/kg intravenously every 2 weeks.

RESULTS

Eight patients were enrolled: three in cohort 1 and five in cohort 2 (two patients were unevaluable due to rapid disease progression and replaced). No dose-limiting toxicities were observed. Treatment-related adverse events (AEs) of any grade in ≥2 patients included nausea (25%) and vomiting (25%). There was one Grade 3 treatment-related AE, a cerebrovascular accident possibly related to ramucirumab. Galunisertib exposure was dose-proportional and not affected by ramucirumab. The RECIST version 1.1 objective response rate and disease control rate were 0% and 12.5%, respectively.

CONCLUSION

Combination therapy was safe and tolerable and displayed favorable PK. The MTD was established at galunisertib at 150 mg orally twice a day and ramucirumab 8 mg/kg intravenously every 2 weeks. The results do not support the preclinical hypothesis that blocking TGFβ signaling enhances efficacy of VEGF-targeted therapy; thus further clinical development was halted for the combination of galunisertib and ramucirumab.

Garcimultiflorone K from Garcinia multiflora attenuates hepatocellular carcinoma metastasis by suppressing transforming growth factor-β signaling

BACKGROUND

Transforming growth factor‑β (TGF-β) signaling is a crucial inducer of tissue fibrosis and extracellular matrix accumulation and a vital suppressor of epithelial cell proliferation and cancer metastasis. The nature of this multifunctional cytokine has prompted the development of TGF-β signaling inhibitors as therapeutic agents. Our research group has recently isolated the polyprenylated polycyclic acylphloroglucinol garcimultiflorone K (GMK) from the stems of Garcinia multiflora; GMK exhibits antiangiogenic activity in endothelial cells.

PURPOSE

In the current study, we aimed to explore the antitumor effect and detailed mechanisms of Garcimultiflorone K in hepatocellular carcinoma cells.

METHODS

Cell proliferation and viability were evaluated using the MTT assay. The migratory ability of HepG2 cells was measured using wound healing assays. The inhibitory effect of GMK against the nuclear translocation of Smad by TGF-β was assessed through immunofluorescence staining and Western blotting. To investigate TGF-β-dependent gene expression profiles upon GMK stimulation, RNA transcript levels were determined using reverse transcription polymerase chain reaction. The effects of GMK in Smad2-driven transcriptomic activities were studied using a reporter gene assay. Protein levels were detected using Western blotting.

RESULTS

Our data revealed that GMK inhibited TGF-β-induced cellular responses, including Smad protein phosphorylation, cell migration, and extracellular matrix production, during epithelial-mesenchymal transition (EMT). Mechanistic studies further demonstrated that GMK suppressed TGF-β signaling by downregulating TGF-β receptor II (TβRII).

CONCLUSION

These findings elucidate that TβRII expression in hepatic cells can be specifically suppressed by GMK to attenuate metastasis and the disease-promoting effects of EMT, representing a therapeutic approach.

Recent progress in TGF-β inhibitors for cancer therapy

Transforming growth factor-β (TGF-β) is a multifunctional cytokine that is involved in proliferation, metastasis, and many other important processes in malignancy. Inhibitors targeting TGF-β have been considered by pharmaceutical companies for cancer therapy, and some of them are in clinical trial now. Unfortunately, several of these programs have recently been relinquished, and most companies that remain in the contest are progressing slowly and cautiously. This review summarizes the TGF-β signal transduction pathway, its roles in oncogenesis and fibrotic diseases, and advancements in antibodies and small-molecule inhibitors of TGF-β.

A Functional SMAD2/3 Binding Site in the PEX11β Promoter Identifies a Role for TGFβ in Peroxisome Proliferation in Humans

In mammals, peroxisomes perform crucial functions in cellular metabolism, signaling and viral defense which are essential to the viability of the organism. Molecular cues triggered by changes in the cellular environment induce a dynamic response in peroxisomes, which manifests itself as a change in peroxisome number, altered enzyme levels and adaptations to the peroxisomal morphology. How the regulation of this process is integrated into the cell's response to different stimuli, including the signaling pathways and factors involved, remains unclear. Here, a cell-based peroxisome proliferation assay has been applied to investigate the ability of different stimuli to induce peroxisome proliferation. We determined that serum stimulation, long-chain fatty acid supplementation and TGFβ application all increase peroxisome elongation, a prerequisite for proliferation. Time-resolved mRNA expression during the peroxisome proliferation cycle revealed a number of peroxins whose expression correlated with peroxisome elongation, including the β isoform of PEX11, but not the α or γ isoforms. An initial map of putative regulatory motif sites in the respective promoters showed a difference between binding sites in PEX11α and PEX11β, suggesting that these genes may be regulated by distinct pathways. A functional SMAD2/3 binding site in PEX11β points to the involvement of the TGFβ signaling pathway in expression of this gene and thus peroxisome proliferation/dynamics in humans.

Galunisertib Drives Treg Fragility and Promotes Dendritic Cell-Mediated Immunity against Experimental Lymphoma

Galunisertib (LY2157299) is a selective ATP-mimetic inhibitor of TGF-β receptor-I activation, currently under clinical trial in a variety of cancers. We have tested the combined effects of galunisertib- and interleukin-15-activated dendritic cells in an aggressive and highly metastatic murine lymphoma. Based on the tumor-draining lymph node architecture, and its histology, the combination therapy results in better prognosis, including disappearance of the disease-exacerbating regulatory T cells. Our data suggest that galunisertib significantly enhances the success of immunotherapy with IL-15-activated dendritic cells by limiting the regulatory T cells generation with consequent downregulation of regulatory T cells in the tumor-draining lymph nodes and vascularized organ like spleen. This is also associated with consistent loss p-SMAD2 and downregulation of Neuropilin-1, leading to better prognosis and positive outcome. These results connect the role of combined therapy with the consequent elimination of disease-exacerbating T regulatory cells in a metastatic murine lymphoma.

•

Galunisertib (LY2157299) + IL-15-activated DC is tumoricidal against DL lymphoma

•

The binary therapy downregulates Treg cell generation in lymph nodes

•

Loss of p-SMAD2 and Neuropilin-1 in lymph nodes with improved prognosis

•

Critical role of central CD8⁺ memory T cells and Treg cells for therapeutic success

The Role of Glypican-1 in the Tumour Microenvironment

Glypican-1 (GPC-1) is a cell surface heparan sulphate proteoglycan that is critical during normal development, but which is not required for normal homoeostasis in the adult. It is, however, overexpressed in a variety of solid tumours and is known to regulate tumour growth, invasion, metastasis and progression, through modulation of tumour cell biology as well as influence on the tumour microenvironment (TME). The role of GPC-1 in the TME and on the tumour cell is broad, as GPC-1 regulates signalling by several growth factors, including FGF, HGF, TGF-β, Wnt and Hedgehog (Hh). Signalling via these pathways promotes tumour growth and invasive and metastatic ability (drives epithelial-to-mesenchymal transition (EMT)) and influences angiogenesis, affecting both tumour and stromal cells. Broad modulation of the TME via inhibition of GPC-1 may represent a novel therapeutic strategy for inhibition of tumour progression. Here, we discuss the complex role of GPC-1 in tumour cells and the TME, with discussion of potential therapeutic targeting strategies.

Therapeutic Targets for the Treatment of Cardiac Fibrosis and Cancer: Focusing on TGF-β Signaling

Transforming growth factor-β (TGF-β) is a common mediator of cancer progression and fibrosis. Fibrosis can be a significant pathology in multiple organs, including the heart. In this review, we explain how inhibitors of TGF-β signaling can work as antifibrotic therapy. After cardiac injury, profibrotic mediators such as TGF-β, angiotensin II, and endothelin-1 simultaneously activate cardiac fibroblasts, resulting in fibroblast proliferation and migration, deposition of extracellular matrix proteins, and myofibroblast differentiation, which ultimately lead to the development of cardiac fibrosis. The consequences of fibrosis include a wide range of cardiac disorders, including contractile dysfunction, distortion of the cardiac structure, cardiac remodeling, and heart failure. Among various molecular contributors, TGF-β and its signaling pathways which play a major role in carcinogenesis are considered master fibrotic mediators. In fact, recently the inhibition of TGF-β signaling pathways using small molecule inhibitors, antibodies, and gene deletion has shown that the progression of several cancer types was suppressed. Therefore, inhibitors of TGF-β signaling are promising targets for the treatment of tissue fibrosis and cancers. In this review, we discuss the molecular mechanisms of TGF-β in the pathogenesis of cardiac fibrosis and cancer. We will review recent in vitro and in vivo evidence regarding antifibrotic and anticancer actions of TGF-β inhibitors. In addition, we also present available clinical data on therapy based on inhibiting TGF-β signaling for the treatment of cancers and cardiac fibrosis.

Paeoniflorin inhibits cell viability and invasion of liver cancer cells via inhibition of Skp2

Paeoniflorin (PF) has been demonstrated to exert tumor suppressive functions in various types of human cancer. However, the mechanisms of PF-mediated anti-tumor activity have not been fully elucidated. S-phase kinase associated protein 2 (Skp2) has been characterized as an oncoprotein that contributes to carcinogenesis. Therefore, the inhibition of Skp2 may be a useful approach for the treatment of various types of human cancer. The present study explored whether PF inhibited the expression of Skp2 in liver cancer cells, leading to cell viability inhibition, induction of apoptosis, and suppression of migration and invasion. PF treatment led to inhibition of Skp2 expression in liver cancer cells. The overexpression of Skp2 abolished PF-mediated anti-cancer activity, whereas the downregulation of Skp2 enhanced this type of activity. The data indicated that PF may be considered as a novel inhibitor of Skp2 in liver cancer cells.

Development of small molecule inhibitors targeting TGF-β ligand and receptor: Structures, mechanism, preclinical studies and clinical usage

Transforming growth factor-β (TGF-β) is a member of a superfamily of pleiotropic proteins that regulate multiple cellular processes such as growth, development and differentiation. Following binding to type I and II TGF-β serine/threonine kinase receptors, TGF-β activates downstream signaling cascades involving both SMAD-dependent and -independent pathways. Aberrant TGF-β signaling is associated with a variety of diseases, such as fibrosis, cardiovascular disease and cancer. Hence, the TGF-β signaling pathway is recognized as a potential drug target. Various organic molecules have been designed and developed as TGF-β signaling pathway inhibitors and they function by either down-regulating the expression of TGF-β or by inhibiting the kinase activities of the TGF-β receptors. In this review, we discuss the current status of research regarding organic molecules as TGF-β inhibitors, focusing on the biological functions and the binding poses of compounds that are in the market or in the clinical or pre-clinical phases of development.

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.

Growth Differentiation Factor 15 Promotes Progression of Esophageal Squamous Cell Carcinoma via TGF-β Type II Receptor Activation

OBJECTIVES

Growth differentiation factor 15 (GDF15), which is derived from tumor-associated macrophages (TAM) and cancer cells, promotes progression of esophageal squamous cell carcinomas (ESCC). However, its role in the ESCC microenvironment remains unclear. Here, we examined the effects of GDF15 on ESCC cell lines and tissues.

METHODS

Western blotting, MTS, and Transwell migration/invasion assays were used to evaluate cell signaling, proliferation, and migration/invasion, respectively, in ESCC cell lines treated with recombinant human GDF15 (rhGDF15). ESCC cell lines were administered a TGF-βRI/II inhibitor (LY2109761), small interfering RNA against TGF-β type II receptor (TGF-βRII), or neutralizing antibody against TGF-βRII to study the role of TGF-βRII in mediating the effects of rhGDF15. The localization of GDF15 and TGF-βRII in ESCC cell lines was observed by immunofluorescence. TGF-βRII expression in ESCC tissues was analyzed by immunohistochemistry, and the relationship between clinicopathological factors and prognosis in ESCC patients was evaluated.

RESULTS

rhGDF15 increased levels of phosphorylated Akt, Erk1/2, and TGF-βRII in ESCC cell lines. Inhibition/knockdown of TGF-βRII suppressed rhGDF15-induced activation of Akt and Erk1/2 and enhancement of cellular proliferation, migration, and invasion. Immunofluorescence revealed that TGF-βRII and GDF15 were colocalized in ESCC cell lines. High TGF-βRII expression in ESCC tissues, as determined by immunohistochemistry, correlated with depth of invasion and increased number of infiltrating TAMs. ESCC patients with high TGF-βRII expression showed a tendency toward poor prognosis.

CONCLUSIONS

GDF15 promotes ESCC progression by increasing cellular proliferation, migration, and invasion via TGF-βRII signaling.

Validation of Hepatocellular Carcinoma Experimental Models for TGF-β Promoting Tumor Progression

Transforming growth factor beta (TGF-β) is a pleiotropic cytokine with dual role in hepatocellular carcinoma (HCC). It acts as tumor-suppressor and tumor-promoter in the early and late stage respectively. TGF-β influences the tumor-stroma cross-talk affecting the tumoral microenvironment. Therefore, inhibiting the TGF- β mediated pathway alone and/or in combination with chemotherapeutics represents an important therapeutic option. Experimental models to dissect the role of TGF-β in HCC tumor progression as well as the effectiveness of specific inhibitors are tricky. HCC cell lines respond to TGF-β according to their epithelial phenotype. However, the mesenchymal and more aggressive HCC cell lines in vitro, do not develop tumors when transplanted in vivo, thus hampering the understanding of molecular pathways that dictate outcome. In addition, in this model the native immune system is abolished, therefore the contribution of inflammation in hepatocarcinogenesis is unreliable. Different strategies have been set up to engineer HCC animal models, including genetically modified mice, chemically induced HCC, or hydrodynamic techniques. Patient-derived xenograft is currently probably the most fascinating model, keeping in mind that models cannot mirror all the reality. In this context, we discuss the different available HCC mouse models including our experimental model treated with inhibitor of TGF-β receptor Type I kinase (Galunisertib) and a potential role of exosomes in TGF-β moderated tumor progression of HCC. Unfortunately, no positive results were obtained in our treated orthotopic model because it does not reproduce the critical tumor-stroma interactions of the HCC.

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.

Population pharmacokinetics and exposure-overall survival analysis of the transforming growth factor-β inhibitor galunisertib in patients with pancreatic cancer

PURPOSE

To evaluate the exposure-overall survival (OS) relationship in patients with advanced pancreatic cancer treated with galunisertib plus gemcitabine (GG) or gemcitabine plus placebo (GP).

METHODS

Galunisertib 300 mg/day was given orally as intermittent dosing and gemcitabine as per label. Galunisertib exposure metrics for each patient in the GG arm (n = 99) of a phase 2 study of pancreatic cancer were calculated. Parametric survival models were used to identify influential baseline and response covariates on OS.

RESULTS

The population pharmacokinetics dataset included data from 297 patients/healthy subjects (age: 22-84 years, weight: 39-126 kg) across multiple studies, including this pancreatic cancer study. Galunisertib was rapidly absorbed with peak concentrations attained within 0.5-2 h and had an elimination half-life of 8 h. Between-subject variance on apparent clearance was estimated to be 47%. Age was the only characteristic to have a statistically significant effect on apparent clearance. A parametric Weibull survival model with treatment effect (dose) estimated a hazard ratio of 0.796, after adjusting for patient baseline factors that were significantly associated with OS. There was also a flat daily exposure-OS relationship within the observed exposure range, once all significant baseline covariates were included. Response covariates, such as reduction in CA19-9, time on treatment, and cumulative exposure over treatment cycles were also identified as significant factors for OS for patients with pancreatic cancer.

CONCLUSIONS

This analysis suggests that 300 mg/day galunisertib administered as 150 mg twice daily for 14 days on/14 days off treatment is an appropriate dosing regimen for patients with pancreatic cancer.

Tumor-specific inhibitory action of decorin on different hepatoma cell lines

BACKGROUND

In spite of therapeutic approaches, liver cancer is still one of the deadliest type of tumor in which tumor microenvironment may play an active role in the outcome of the disease. Decorin, a small leucine-rich proteoglycan is not only responsible for assembly and maintenance of the integrity of the extracellular matrix, but a natural inhibitor of cell surface receptors, thus it exerts antitumorigenic effects. Here we addressed the question whether this effect of decorin is independent of the tumor phenotypes including differentiation, proliferation and invasion.

METHOD

Four hepatoma cell lines HepG2, Hep3B, HuH7 and HLE, possessing different molecular backgrounds, were selected to investigate. After proliferation tests, pRTK arrays, WB analyses, and immunofluorescent examinations were performed on decorin treated and control cells for comparison.

RESULTS

Significant growth inhibitory potential of decorin on three out of four hepatoma cell lines was proven, however the mode of its action was different. Induction of p21^WAF1/CIP1, increased inactivation of c-myc and β-catenin, and decrease of EGFR, GSK3β and ERK1/2 phosphorylation levels were observed in HepG2 cells, pathways already well-described in literature. However, in the p53 deficient Hep3B and HuH7, InsR and IGF-1R were the main receptors transmitting signals. In harmony with its receptor status, Hep3B cells displayed high level of activated AKT. As the cell line is retinoblastoma mutant, ATR/Chk1/Wee1 system might hinder the cell cycle in G2/M phase via phosphorylation of CDK1. In Huh7 cells, all RTKs were inhibited by decorin followed by downregulation of AKT. Furthermore, HuH7 cell line responded with concentration-dependent ERK activation and increased phospho-c-myc level. Decorin had only a non-significant effect on the proliferation rate of HLE cell line. However, it responded with a significant decrease of pAKT, c-myc and β-catenin activity. In this special cell line, the inhibition of TGFβ may be the first step of the protective effect of decorin.

CONCLUSIONS

Based on our results decorin may be a candidate therapeutic agent in the battle against liver cancer, but several questions need to be answered. It is certain that decorin is capable to exert its suppressor effect in hepatoma cells without respect to their phenotype and molecular background.

Current status and future prospects of transforming growth factor-β as a potential prognostic and therapeutic target in the treatment of breast cancer

The transforming growth factor-β (TGF-β) signaling pathway is one of the important pathways involved in the cancer cell proliferation, invasion, migration, angiogenesis, apoptosis, as well as in metastasis by agitation or invasion of metastasis-related factors, including matrix metalloproteinase (MMP), epithelial-to-mesenchymal transition (EMT), tumor microenvironment (TME), cancer stem cells (CSCs), and cell adhesion molecules (CAMs). These data suggest its potential value as a therapeutic object in the treatment of malignancies including breast cancer. Several pharmacological approaches have been established to suppress TGF-β pathway; such as vaccines, small molecular inhibitors, antisense oligonucleotides, and monoclonal antibodies. Some of these are now approved by the US Food and Drug Administration for targeting the TGF-β signaling pathway. This study attempts to summarize the current data about the functions of TGF-β in cancer cells, and their probable application in the cancer therapy with a specific emphasis on recent preclinical and clinical research in the treatment of breast cancer and its prognostic value.

Transforming Growth Factor-β Promotes Morphomechanical Effects Involved in Epithelial to Mesenchymal Transition in Living Hepatocellular Carcinoma

The epithelial mesenchymal transition (EMT) is a physiological multistep process involving epithelial cells acquiring a mesenchymal-like phenotype. It is widely demonstrated that EMT is linked to tumor progression and metastasis. The transforming growth factor (TGF)-β pathways have been widely investigated, but its role in the hepatocarcinoma EMT is still unclear. While the biochemical pathways have been extensively studied, the alteration of biomechanical behavior correlated to cellular phenotype and motility is not yet fully understood. To better define the involvement of TGF-β1 in the metastatic progression process in different hepatocarcinoma cell lines (HepG2, PLC/PRF/5, HLE), we applied a systematic morphomechanical approach in order to investigate the physical and the structural characteristics. In addition, we evaluated the antitumor effect of LY2157299, a TGF-βR1 kinase inhibitor, from a biomechanical point of view, using Atomic Force and Confocal Microscopy. Our approach allows for validation of biological data, therefore it may be used in the future as a diagnostic tool to be combined with conventional biomolecular techniques.

Cancer stem cells in hepatocellular carcinoma: an overview and promising therapeutic strategies

The poor clinical outcome of hepatocellular carcinoma (HCC) patients is ascribed to the resistance of HCC cells to traditional treatments and tumor recurrence after curative therapies. Cancer stem cells (CSCs) have been identified as a small subset of cancer cells which have high capacity for self-renewal, differentiation and tumorigenesis. Recent advances in the field of liver CSCs (LCSCs) have enabled the identification of CSC surface markers and the isolation of CSC subpopulations from HCC cells. Given their central role in cancer initiation, metastasis, recurrence and therapeutic resistance, LCSCs constitute a therapeutic opportunity to achieve cure and prevent relapse of HCC. Thus, it is necessary to develop therapeutic strategies to selectively and efficiently target LCSCs. Small molecular inhibitors targeting the core stemness signaling pathways have been actively pursued and evaluated in preclinical and clinical studies. Other alternative therapeutic strategies include targeting LCSC surface markers, interrupting the CSC microenvironment, and altering the epigenetic state. In this review, we summarize the properties of CSCs in HCC and discuss novel therapeutic strategies that can be used to target LCSCs.

Transforming Growth Factor-β-Induced Cell Plasticity in Liver Fibrosis and Hepatocarcinogenesis

The Transforming Growth Factor-beta (TGF-β) family plays relevant roles in the regulation of different cellular processes that are essential for tissue and organ homeostasis. In the case of the liver, TGF-β signaling participates in different stages of disease progression, from initial liver injury toward fibrosis, cirrhosis and cancer. When a chronic injury takes place, mobilization of lymphocytes and other inflammatory cells occur, thus setting the stage for persistence of an inflammatory response. Macrophages produce profibrotic mediators, among them, TGF-β, which is responsible for activation -transdifferentiation- of quiescent hepatic stellate cells (HSC) to a myofibroblast (MFB) phenotype. MFBs are the principal source of extracellular matrix protein (ECM) accumulation and prominent mediators of fibrogenesis. TGF-β also mediates an epithelial-mesenchymal transition (EMT) process in hepatocytes that may contribute, directly or indirectly, to increase the MFB population. In hepatocarcinogenesis, TGF-β plays a dual role, behaving as a suppressor factor at early stages, but contributing to later tumor progression, once cells escape from its cytostatic effects. As part of its potential pro-tumorigenic actions, TGF-β induces EMT in liver tumor cells, which increases its pro-migratory and invasive potential. In parallel, TGF-β also induces changes in tumor cell plasticity, conferring properties of a migratory tumor initiating cell (TIC). The main aim of this review is to shed light about the pleiotropic actions of TGF-β that explain its effects on the different liver cell populations. The cross-talk with other signaling pathways that contribute to TGF-β effects, in particular the Epidermal Growth Factor Receptor (EGFR), will be presented. Finally, we will discuss the rationale for targeting the TGF-β pathway in liver pathologies.

LY2157299 Monohydrate, a TGF-βR1 Inhibitor, Suppresses Tumor Growth and Ascites Development in Ovarian Cancer

Transforming growth factor beta (TGF-β) signaling has pleiotropic functions regulating cancer initiation, development, and metastasis, and also plays important roles in the interaction between stromal and cancer cells, making the pathway a potential therapeutic target. LY2157299 monohydrate (LY), an inhibitor of TGF-β receptor I (TGFBRI), was examined for its ability to inhibit ovarian cancer (OC) growth both in high-grade serous ovarian cancer (HGSOC) cell lines and xenograft models. Immunohistochemistry, qRT-PCR, and Western blot were performed to study the effect of LY treatment on expression of cancer- and fibroblast-derived genes. Results showed that exposure to TGF-β1 induced phosphorylation of SMAD2 and SMAD3 in all tested OC cell lines, but this induction was suppressed by pretreatment with LY. LY alone inhibited the proliferation, migration, and invasion of HGSOC cells in vitro. TGF-β1-induced fibroblast activation was blocked by LY. LY also delayed tumor growth and suppressed ascites formation in vivo. In addition, independent of tumor inhibition, LY reduces ascites formation in vivo. Using OVCAR8 xenograft specimens we confirmed the inhibitory effect of LY on TGF-β signaling and tumor stromal expression of collagen type XI chain 1 (COL11A1) and versican (VCAN). These observations suggest a role for anti-TGF-β signaling-directed therapy in ovarian cancer.

Galunisertib modifies the liver fibrotic composition in the Abcb4Ko mouse model

Transforming growth factor (TGF)-β stimulates extracellular matrix (ECM) deposition during development of liver fibrosis and cirrhosis, the most important risk factor for the onset of hepatocellular carcinoma. In liver cancer, TGF-β is responsible for a more aggressive and invasive phenotype, orchestrating remodeling of the tumor microenvironment and triggering epithelial-mesenchymal transition of cancer cells. This is the scientific rationale for targeting the TGF-β pathway via a small molecule, galunisertib (intracellular inhibitor of ALK5) in clinical trials to treat liver cancer patients at an advanced disease stage. In this study, the hypothesis that galunisertib modifies the tissue microenvironment via inhibition of the TGF-β pathway is tested in an experimental preclinical model. At the age of 6 months, Abcb4ko mice-a well-established model for chronic liver disease development and progression-are treated twice daily with galunisertib (150 mg/kg) via oral gavage for 14 consecutive days. Two days after the last treatment, blood plasma and livers are harvested for further assessment, including fibrosis scoring and ECM components. The reduction of Smad2 phosphorylation in both parenchymal and non-parenchymal liver cells following galunisertib administration confirms the treatment effectiveness. Damage-related galunisertib does not change cell proliferation, macrophage numbers and leucocyte recruitment. Furthermore, no clear impact on the amount of fibrosis is evident, as documented by PicroSirius red and Gomori-trichome scoring. On the other hand, several fibrogenic genes, e.g., collagens (Col1α1 and Col1α2), Tgf-β1 and Timp1, mRNA levels are significantly downregulated by galunisertib administration when compared to controls. Most interestingly, ECM/stromal components, fibronectin and laminin-332, as well as the carcinogenic β-catenin pathway, are remarkably reduced by galunisertib-treated Abcb5ko mice. In conclusion, TGF-β inhibition by galunisertib interferes, to some extent, with chronic liver progression, not by reducing the stage of liver fibrosis as measured by different scoring systems, but rather by modulating the biochemical composition of the deposited ECM, likely affecting the fate of non-parenchymal cells.

Periostin, a signal transduction intermediate in TGF-β-induced EMT in U-87MG human glioblastoma cells, and its inhibition by anthocyanidins

Periostin is a secreted protein that is highly expressed in glioblastoma cells as compared to normal brain tissue, and is therefore considered as a potential biomarker in therapeutic modalities. Its contribution in the cancer cells invasive phenotype is, however, poorly understood. This work investigates the role of periostin in U-87 MG glioblastoma cell invasion, cell migration and in Transforming Growth Factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT). Periostin gene silencing, using small interfering RNA, decreased TGF-β-induced mesenchymal marker expression of fibronectin and vimentin, partly through reduced Smad2, Akt and Fak phosphorylation as well as U-87 MG cell invasion and migration. The effects of anthocyanidins, the most abundant diet-derived flavonoids, were examined on periostin-mediated downstream signaling pathways. Anthocyanidins were found to decrease periostin expression whether added under pre-, co- or post-treatment conditions along with TGF-β, and altered the Akt and Fak signaling pathways. These effects were similar to Galunisertib (LY2157299), a small molecule inhibitor of the TGF-β receptor I kinase. Taken together, our data demonstrate that periostin acts as a central element in TGF-β-induced EMT, which can be prevented by diet-derived anthocyanidins.

Galunisertib suppresses the staminal phenotype in hepatocellular carcinoma by modulating CD44 expression

Cancer stem cells (CSCs) niche in the tumor microenvironment is responsible for cancer recurrence and therapy failure. To better understand its molecular and biological involvement in hepatocellular carcinoma (HCC) progression, one can design more effective therapies and tailored then to individual patients. While sorafenib is currently the only approved drug for first-line treatment of advanced stage HCC, its role in modulating the CSC niche is estimated to be small. By contrast, transforming growth factor (TGF)-β pathway seems to influence the CSC and thus may impact hallmarks of HCC, such as liver fibrosis, cirrhosis, and tumor progression. Therefore, blocking this pathway may offer an appealing and druggable target. In our study, we have used galunisertib (LY2157299), a selective ATP-mimetic inhibitor of TGF-β receptor I (TGFβI/ALK5) activation, currently under clinical investigation in HCC patients. Because the drug resistance is mainly mediated by CSCs, we tested the effects of galunisertib on stemness phenotype in HCC cells to determine whether TGF-β signaling modulates CSC niche and drug resistance. Galunisertib modulated the expression of stemness-related genes only in the invasive (HLE and HLF) HCC cells inducing a decreased expression of CD44 and THY1. Furthermore, galunisertib also reduced the stemness-related functions of invasive HCC cells decreasing the formation of colonies, liver spheroids and invasive growth ability. Interestingly, CD44 loss of function mimicked the galunisertib effects on HCC stemness-related functions. Galunisertib treatment also reduced the expression of stemness-related genes in ex vivo human HCC specimens. Our observations are the first evidence that galunisertib effectiveness overcomes stemness-derived aggressiveness via decreased expression CD44 and THY1.

Organ-On-A-Chip Platforms: A Convergence of Advanced Materials, Cells, and Microscale Technologies

Significant advances in biomaterials, stem cell biology, and microscale technologies have enabled the fabrication of biologically relevant tissues and organs. Such tissues and organs, referred to as organ-on-a-chip (OOC) platforms, have emerged as a powerful tool in tissue analysis and disease modeling for biological and pharmacological applications. A variety of biomaterials are used in tissue fabrication providing multiple biological, structural, and mechanical cues in the regulation of cell behavior and tissue morphogenesis. Cells derived from humans enable the fabrication of personalized OOC platforms. Microscale technologies are specifically helpful in providing physiological microenvironments for tissues and organs. In this review, biomaterials, cells, and microscale technologies are described as essential components to construct OOC platforms. The latest developments in OOC platforms (e.g., liver, skeletal muscle, cardiac, cancer, lung, skin, bone, and brain) are then discussed as functional tools in simulating human physiology and metabolism. Future perspectives and major challenges in the development of OOC platforms toward accelerating clinical studies of drug discovery are finally highlighted.

TGF-β signaling is an effective target to impair survival and induce apoptosis of human cholangiocarcinoma cells: A study on human primary cell cultures

Cholangiocarcinoma (CCA) and its subtypes (mucin- and mixed-CCA) arise from the neoplastic transformation of cholangiocytes, the epithelial cells lining the biliary tree. CCA has a high mortality rate owing to its aggressiveness, late diagnosis and high resistance to radiotherapy and chemotherapeutics. We have demonstrated that CCA is enriched for cancer stem cells which express epithelial to mesenchymal transition (EMT) traits, with these features being associated with aggressiveness and drug resistance. TGF-β signaling is upregulated in CCA and involved in EMT. We have recently established primary cell cultures from human mucin- and mixed-intrahepatic CCA. In human CCA primary cultures with different levels of EMT trait expression, we evaluated the anticancer effects of: (i) CX-4945, a casein kinase-2 (CK2) inhibitor that blocks TGF-β1-induced EMT; and (ii) LY2157299, a TGF-β receptor I kinase inhibitor. We tested primary cell lines expressing EMT trait markers (vimentin, N-cadherin and nuclear catenin) but negative for epithelial markers, and cell lines expressing epithelial markers (CK19-positive) in association with EMT traits. Cell viability was evaluated by MTS assays, apoptosis by Annexin V FITC and cell migration by wound-healing assay. Results: at a dose of 10 μM, CX4945 significantly decreased cell viability of primary human cell cultures from both mucin and mixed CCA, whereas in CK19-positive cell cultures, the effect of CX4945 on cell viability required higher concentrations (>30μM). At the same concentrations, CX4945 also induced apoptosis (3- fold increase vs controls) which correlated with the expression level of CK2 in the different CCA cell lines (mucin- and mixed-CCA). Indeed, no apoptotic effects were observed in CK19-positive cells expressing lower CK2 levels. The effects of CX4945 on viability and apoptosis were associated with an increased number of γ-H2ax (biomarker for DNA double-strand breaks) foci, suggesting the active role of CK2 as a repair mechanism in CCAs. LY2157299 failed to influence cell proliferation or apoptosis but significantly inhibited cell migration. At a 50 μM concentration, in fact, LY2157299 significantly impaired (at 24, 48 and 120 hrs) the wound-healing of primary cell cultures from both mucin-and mixed-CCA. In conclusion, we demonstrated that CX4945 and LY2157299 exert relevant but distinct anticancer effects against human CCA cells, with CX4945 acting on cell viability and apoptosis, and LY2157299 impairing cell migration. These results suggest that targeting the TGF-β signaling with a combination of CX-4945 and LY2157299 could have potential benefits in the treatment of human CCA.

Role of IQGAP3 in metastasis and epithelial-mesenchymal transition in human hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide owing to its high rates of metastasis and recurrence. The oncogene IQ motif-containing GTPase activating protein 3 (IQGAP3) is ubiquitously overexpressed in several human cancers, including liver, ovary, lung, large intestine, gastric, bone marrow, and breast malignancies and is involved in the invasion and metastasis of cancer cells. Therefore, we aimed to determine the biological role and molecular mechanism of IQGAP3 in HCC.

Methods

We used 120 archived clinical HCC samples, 9 snap-frozen HCC tumor tissues, and 4 normal liver tissues. Expression of IQGAP3 mRNA and protein in HCC cell lines (Hep3B, SMMC-7721, HCCC-9810, HepG2, BEL-7404, HCCLM3, QGY-7701, Huh7, and MHCC97H) and normal liver epithelial cells LO2 was examined by western blot, quantitative polymerase chain reaction, and immunohistochemistry. In addition, wound-healing and transwell matrix penetration assays were used to assess the migratory and invasive abilities of HCC cells, respectively.

Results

Expression of the IQGAP3 was robustly upregulated in HCC cells and tissues. High expression of IQGAP3 in HCC correlated with aggressive clinicopathological features and was an independent poor prognostic factor for overall survival. Furthermore, ectopic expression of IQGAP3 markedly enhanced HCC cell migration, invasion, and epithelial-to-mesenchymal transition (EMT) in vitro and promoted metastasis of orthotopic hepatic tumors in nude mice. Conversely, silencing endogenous IQGAP3 showed an opposite effect. Mechanistically, IQGAP3 promoted EMT and metastasis by activating TGF-β signaling.

Conclusions

IQGAP3 functions as an important regulator of metastasis and EMT by constitutively activating the TGF-β signaling pathway in HCC. Our findings present new evidence of the role of IQGAP3 in EMT and metastasis, indicating its potential as a prognostic biomarker candidate and a therapeutic target against HCC.

TGFβ Controls Ovarian Cancer Cell Proliferation

There have been no major improvements in the overall survival of ovarian cancer patients in recent decades. Even though more accurate surgery and more effective treatments are available, the mortality rate remains high. Given the differences in origin and the heterogeneity of these tumors, research to elucidate the signaling pathways involved is required. The Transforming Growth Factor (TGFβ) family controls different cellular responses in development and cell homeostasis. Disruption of TGFβ signaling has been implicated in many cancers, including ovarian cancer. This article considers the involvement of TGFβ in ovarian cancer progression, and reviews the various mechanisms that enable the TGFβ signaling pathway to control ovarian cancer cell proliferation. These mechanistic explanations support the therapeutic use of TGFβ inhibitors in ovarian cancer, which are currently in the early phases of development.

Hook1 inhibits malignancy and epithelial–mesenchymal transition in hepatocellular carcinoma

Hook1 is a member of the hook family of coiled-coil proteins, which is recently found to be associated with malignant tumors. However, its biological function in hepatocellular carcinoma is yet unknown. Here, we evaluated the Hook1 levels in human hepatocellular carcinoma samples and matched peritumoral tissues by real-time polymerase chain reaction. Small interfering RNA knockdown and a transforming growth factor-β-induced epithelial–mesenchymal transition model were employed to investigate the biological effects of Hook1 in hepatocellular carcinoma. Our results indicated that Hook1 levels were significantly lower in hepatocellular carcinoma tissues than in the peritumoral tissues. In addition, Hook1 expression was significantly associated with hepatocellular carcinoma malignancy. Hook1 was downregulated after transforming growth factor-β-induced epithelial–mesenchymal transition. Moreover, Hook1 knockdown promoted epithelial–mesenchymal transition and attenuated the sensitivity of hepatocellular carcinoma cells to doxorubicin. In summary, our results indicate that downregulation of Hook1 plays a pivotal role in hepatocellular carcinoma progression via epithelial–mesenchymal transition. Hook1 may be used as a novel marker and therapeutic molecular target in hepatocellular carcinoma.

Precision medicine for hepatocelluar carcinoma using molecular pattern diagnostics: results from a preclinical pilot study

The aim of this study was to design a road map for personalizing cancer therapy in hepatocellular carcinoma (HCC) by using molecular pattern diagnostics. As an exploratory study, we investigated molecular patterns of tissues of two tumors from individual HCC patients, which in previous experiments had shown contrasting reactions to the phase 2 transforming growth factor beta receptor 1 inhibitor galunisertib. Cancer-driving molecular patterns encompass – inter alias – altered transcription profiles and somatic mutations in coding regions differentiating tumors from their respective peritumoral tissues and from each other. Massive analysis of cDNA ends and all-exome sequencing demonstrate a highly divergent transcriptional and mutational landscape, respectively, for the two tumors, that offers potential explanations for the tumors contrasting responses to galunisertib. Molecular pattern diagnostics (MPDs) suggest alternative, individual-tumor-specific therapies, which in both cases deviate from the standard sorafenib treatment and from each other. Suggested personalized therapies use kinase inhibitors and immune-focused drugs as well as low-toxicity natural compounds identified using an advanced bioinformatics routine included in the MPD protocol. The MPD pipeline we describe here for the prediction of suitable drugs for treatment of two contrasting HCCs may serve as a blueprint for the design of therapies for various types of cancer.

Galunisertib (LY2157299), a transforming growth factor-β receptor I kinase inhibitor, attenuates acute pancreatitis in rats

Galunisertib (LY2157299), a selective ATP-mimetic inhibitor of TGF-β receptor I (TGF-βRI), is the only known TGF-β pathway inhibitor. In the present study, we investigated the effect of galunisertib on taurocholate (TAC)-induced acute pancreatitis (AP) in rats, and the role of TGF-β and NF-κB signaling pathways. AP was induced by infusion of TAC into the pancreatic duct of Sprague-Dawley male rats (n=30). The rats (220±50 g) were administered galunisertib intragastrically [75 mg·kg^-1·day^-1 for 2 days (0 and 24 h)]. Serum IL-1β, IL-6, TNF-α, amylase (AMY), lipase (LIP), and myeloperoxidase (MPO) levels were measured by ELISA. NF-κB activity was detected by electrophoretic mobility shift assay (EMSA); NF-κBp65 and TGF-β1 proteins, as well as TGF-βRI and p-Smad2/3 proteins, were detected by western blot assay. Cell apoptosis was detected by TUNEL assay. H&E staining was used to evaluate the histopathological alterations of the pancreas. Galunisertib treatment attenuated the severity of AP and decreased the pancreatic histological score. In addition, number of apoptotic cells were significantly increased in the galunisertib-treated group (16.38±2.26) than in the AP group (8.14±1.27) and sham-operated group (1.82±0.73; P<0.05 and P<0.01, respectively). Galunisertib decreased the expression levels of TGF-βRI and p-Smad2/3 and inhibited NF-κB activation and p65 translocation compared with the sham-operated group. Furthermore, serum IL-1β, IL-6, TNF-α, AMY and LIP levels and tissue MPO activity were significantly decreased in the galunisertib-treated group. Our data demonstrate that galunisertib attenuates the severity of TAC-induced experimental AP in rats by inducing apoptosis in the pancreas, inhibiting the activation of TGF-β signals and NF-κB as well as the secretion of pro-inflammatory cytokines.

Transforming growth factor-β: A therapeutic target for cancer

Transforming growth factor-β (TGF-β) regulates cell growth and differentiation, apoptosis, cell motility, extracellular matrix production, angiogenesis, and cellular immunity. It has a paradoxical role in cancer. In the early stages it inhibits cellular transformation and prevents cancer progression. In later stages TGF-β plays a key role in promoting tumor progression through mainly 3 mechanisms: facilitating epithelial to mesenchymal transition, stimulating angiogenesis and inducing immunosuppression. As a result of its opposing tumor promoting and tumor suppressive abilities, TGF-β and its pathway has represented potential opportunities for drug development and several therapies targeting the TGF-β pathway have been identified. This review focuses on identifying the mechanisms through which TGF-β is involved in tumorigenesis and current therapeutics that are under development.

[PCR analysis of the absolute number of copies of human chromosome 18 transcripts in liver and HepG2 cells]

Using reverse transcription in conjunction with the quantitative real-time PCR or digital droplet PCR, the transcriptome profiling of human chromosome 18 has been carried out in liver hepatocytes and hepatoblastoma cells (HepG2 cell line) in terms of the absolute number of each transcript per cell. The transcript abundance varies within the range of 0.006 to 9635 and 0.011 to 4819 copies per cell for HepG2 cell line and hepatocytes, respectively. The expression profiles for genes of chromosome 18 in hepatocytes and HepG2 cells were found to significantly correlate: the Spearman's correlation coefficient was equal to 0.81. The distribution of frequency of transcripts over their abundance was bimodal for HepG2 cells and unimodal for liver hepatocytes. Bioinformatic analysis of the differential gene expression has revealed that genes of chromosome 18, overexpressed in HepG2 cells compared to hepatocytes, are associated with cell division and cell adhesion processes. It is assumed that the enhanced expression of those genes in HepG2 cells is related to the proliferation activity of cultured cells. The differences in transcriptome profiles have to be taken into account when modelling liver hepatocytes with cultured HepG2 cells.

NGS-based transcriptome profiling reveals biomarkers for companion diagnostics of the TGF-β receptor blocker galunisertib in HCC

Transforming growth factor-beta (TGF-β) signaling has gained extensive interest in hepatocellular carcinoma (HCC). The small molecule kinase inhibitor galunisertib, targeting the TGF-β receptor I (TGF-βRI), blocks HCC progression in preclinical models and shows promising effects in ongoing clinical trials. As the drug is not similarly effective in all patients, this study was aimed at identifying new companion diagnostics biomarkers for patient stratification. Next-generation sequencing-based massive analysis of cDNA ends was used to investigate the transcriptome of an invasive HCC cell line responses to TGF-β1 and galunisertib. These identified mRNA were validated in 78 frozen HCC samples and in 26 ex-vivo HCC tissues treated in culture with galunisertib. Respective protein levels in patients blood were measured by enzyme-linked immunosorbent assay. SKIL, PMEPA1 ANGPTL4, SNAI1, Il11 and c4orf26 were strongly upregulated by TGF-β1 and downregulated by galunisertib in different HCC cell lines. In the 78 HCC samples, only SKIL and PMEPA1 (P<0.001) were correlated with endogenous TGF-β1. In ex-vivo samples, SKIL and PMEPA1 were strongly downregulated (P<0.001), and correlated (P<0.001) with endogenous TGF-β1. SKIL and PMEPA1 mRNA expression in tumor tissues was significantly increased compared with controls and not correlated with protein levels in the blood of paired HCC patients. SKIL and PMEPA1 mRNA levels were positively correlated with TGF-β1 mRNA concentrations in HCC tissues and strongly downregulated by galunisertib. The target genes identified here may serve as biomarkers for the stratification of HCC patients undergoing treatment with galunisertib.

Stem cell, biomaterials and growth factors therapy for hepatocellular carcinoma

Hepatocellular carcinoma is an antecedent of liver illnesses, including viral hepatitis, alcohol abuse, or metabolic disease. Transforming growth factor-Beta (TGF-b) plays an important role in creating a favorable microenvironment for tumor cell growth via two major mechanisms: an intrinsic activity as an autocrine growth factor and an extrinsic activity by inducing microenvironment changes. Recently stem cell therapy as also been a promising and potential treatment for liver cancer and in addition signaling pathways like GF/GFR systems, SDF-1α/CXC4 ligand receptor interaction and PI3K/Akt signaling, and cytokines has been identified to regulate cell fate decisions, and can be utilized to positively influence cell therapy outcomes. Thus stem cell-based therapy, together with signaling pathways can become a practical option in regenerative processes for replacing dead hepatocytes cells. Targeted drug delivery systems (TDDS) via biomaterials are presently been explored for cancer therapeutics especially liver cancer as it allows the enhancement of drug concentration in the liver and decrease the dosage and side effects. This review is intended to give a comprehensive summary of available liver cancer therapy using stem cells, growth factor and biomaterials.

A Small Dibromotyrosine Derivative Purified From Pseudoceratina Sp. Suppresses TGF-β Responsiveness by Inhibiting TGF-β Type I Receptor Serine/Threonine Kinase Activity

For clinical application, there is a great need for small-molecule inhibitors (SMIs) that could control pathogenic effects of transforming growth factor (TGF-β) and/or modulate effects of TGF-β in normal responses. Selective SMIs of the TGF-β signaling pathway developed for therapeutics will also be powerful tools in experimentally dissecting this complex pathway, especially its cross-talk with other signaling pathways. In this study, we characterized (1'R,5'S,6'S)-2-(3',5'-dibromo-1',6'-dihydroxy-4'-oxocyclohex-2'-enyl) acetonitrile (DT), a member of a new class of small-molecule inhibitors related to bromotyrosine derivate from Pseudoceratina sp., which inhibits the TGF-β type I receptor serine/threonine kinase known as activin receptor-like kinase (ALK) 5. The inhibitory effects of DT on TGF-β-induced Smad signaling and epithelial-to-mesenchymal transition (EMT) were investigated in epithelial cells using in vitro kinase assay, luciferase reporter assays, immunoblotting, confocal microscopy, and wound healing assays. The novel ALK5 inhibitor, DT, inhibited the TGF-β-stimulated transcriptional activations of 3TP-Lux. In addition, DT decreased phosphorylated Smad2/3 levels and the nuclear translocation of Smad2/3 increased by TGF-β. In addition, DT inhibited TGF-β-induced EMT and wound healing of A549 cells. Our results suggest that DT is a potential therapeutic agent for fibrotic disease and cancer treatment. J. Cell. Biochem. 117: 2800-2814, 2016. © 2016 Wiley Periodicals, Inc.

Effects of TGF-beta signalling inhibition with galunisertib (LY2157299) in hepatocellular carcinoma models and in ex vivo whole tumor tissue samples from patients

Galunisertib (LY2157299) is a selective ATP-mimetic inhibitor of TGF-β receptor (TβR)-I activation currently under clinical investigation in hepatocellular carcinoma (HCC) patients. Our study explored the effects of galunisertib in vitro in HCC cell lines and ex vivo on patient samples. Galunisertib was evaluated in HepG2, Hep3B, Huh7, JHH6 and SK-HEP1 cells as well as in SK-HEP1-derived cells tolerant to sorafenib (SK-Sora) and sunitinib (SK-Suni). Exogenous stimulation of all HCC cell lines with TGF-β yielded downstream activation of p-Smad2 and p-Smad3 that was potently inhibited with galunisertib treatment at micromolar concentrations. Despite limited antiproliferative effects, galunisertib yielded potent anti-invasive properties. Tumor slices from 13 patients with HCC surgically resected were exposed ex vivo to 1 μM and 10 μM galunisertib, 5 μM sorafenib or a combination of both drugs for 48 hours. Galunisertib but not sorafenib decreased p-Smad2/3 downstream TGF-β signaling. Immunohistochemistry analysis of galunisertib and sorafenib-exposed samples showed a significant decrease of the proliferative marker Ki67 and increase of the apoptotic marker caspase-3. In combination, galunisertib potentiated the effect of sorafenib efficiently by inhibiting proliferation and increasing apoptosis. Our data suggest that galunisertib may be active in patients with HCC and could potentiate the effects of sorafenib.

Musashi-2 (MSI2) supports TGF-β signaling and inhibits claudins to promote non-small cell lung cancer (NSCLC) metastasis

Non-small cell lung cancer (NSCLC) has a 5-y survival rate of ∼16%, with most deaths associated with uncontrolled metastasis. We screened for stem cell identity-related genes preferentially expressed in a panel of cell lines with high versus low metastatic potential, derived from NSCLC tumors of Kras(LA1/+);P53(R172HΔG/+) (KP) mice. The Musashi-2 (MSI2) protein, a regulator of mRNA translation, was consistently elevated in metastasis-competent cell lines. MSI2 was overexpressed in 123 human NSCLC tumor specimens versus normal lung, whereas higher expression was associated with disease progression in an independent set of matched normal/primary tumor/lymph node specimens. Depletion of MSI2 in multiple independent metastatic murine and human NSCLC cell lines reduced invasion and metastatic potential, independent of an effect on proliferation. MSI2 depletion significantly induced expression of proteins associated with epithelial identity, including tight junction proteins [claudin 3 (CLDN3), claudin 5 (CLDN5), and claudin 7 (CLDN7)] and down-regulated direct translational targets associated with epithelial-mesenchymal transition, including the TGF-β receptor 1 (TGFβR1), the small mothers against decapentaplegic homolog 3 (SMAD3), and the zinc finger proteins SNAI1 (SNAIL) and SNAI2 (SLUG). Overexpression of TGFβRI reversed the loss of invasion associated with MSI2 depletion, whereas overexpression of CLDN7 inhibited MSI2-dependent invasion. Unexpectedly, MSI2 depletion reduced E-cadherin expression, reflecting a mixed epithelial-mesenchymal phenotype. Based on this work, we propose that MSI2 provides essential support for TGFβR1/SMAD3 signaling and contributes to invasive adenocarcinoma of the lung and may serve as a predictive biomarker of NSCLC aggressiveness.

Epithelial-mesenchymal transition and related signaling pathways in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common forms of liver cancer and the third leading cause of cancer-related mortality in the world. Although numerous therapeutic strategies have been employed to treat this fatal disease, the prognosis of HCC patients remains dismal with a low 5-year survival rate of approximately 30%. Postoperative recurrence and metastasis of HCC are the leading cause of poor prognosis. Metastasis has been thought to rely on non-motile epithelial tumor cells acquiring characteristics of mesenchymal cells, which are more migratory. This change is known as the epithelial-to-mesenchymal transition (EMT). EMT has been considered one of the main reasons for the invasion and metastasis of HCC. Notably, increasing evidence indicates that several signaling pathways participate in the regulation of EMT in HCC. In the current review, we will discuss the current progress in research of EMT and its related signaling pathways in HCC.

The rationale for targeting TGF-β in chronic liver diseases

BACKGROUND

Transforming growth factor (TGF)-β is a pluripotent cytokine that displays several tissue-specific biological activities. In the liver, TGF-β is considered a fundamental molecule, controlling organ size and growth by limiting hepatocyte proliferation. It is involved in fibrogenesis and, therefore, in worsening liver damage, as well as in triggering the development of hepatocellular carcinoma (HCC). TGF-β is known to act as an oncosuppressor and also as a tumour promoter in HCC, but its role is still unclear.

DESIGN

In this review, we discuss the potential role of TGF-β in regulating the tumoural progression of HCC, and therefore the rationale for targeting this molecule in patients with HCC.

RESULTS

A considerable amount of experimental preclinical evidence suggests that TGF-β is a promising druggable target in patients with HCC. To support this hypothesis, a phase II clinical trial is currently ongoing using a TGF-β pathway inhibitor, and results will soon be available.

CONCLUSIONS

The identification of new TGF-β related biomarkers will help to select those patients most likely to benefit from therapy aimed at inhibiting the TGF-β pathway. New formulations that may provide a more controlled and sustained delivery of the drug will improve the therapeutic success of such treatments.