Tumor necrosis factor-α (TNF-α) stimulates the epithelial-mesenchymal transition regulator Snail in cholangiocarcinoma. Med Oncol. 2012;29:3083-3091. [PMID: 22903530 DOI: 10.1007/s12032-012-0305-x]

Atovaquone inhibits colorectal cancer metastasis by regulating PDGFRβ/NF-κB signaling pathway

BACKGROUND

Colorectal cancer is a common malignant tumour. Invasive growth and distant metastasis are the main characteristics of its malignant biological behaviour, and they are also the primary factors leading to death in colon cancer patients. Atovaquone is an antimalarial drug, and its anticancer effect has recently been demonstrated in several cancer models in vitro and in vivo, but it has not been examined in the treatment of colorectal cancer.

METHODS

To elucidate the effect of atovaquone on colorectal cancer. We used RNA transcriptome sequencing, RT‒PCR and Western blot experiments to examine the expression of NF-κB (p-P65), EMT-related proteins and related inflammatory factors (IL1B, IL6, CCL20, CCL2, CXCL8, CXCL6, IL6ST, FAS, IL10 and IL1A). The effect of atovaquone on colorectal cancer metastasis was validated using an animal model of lung metastases. We further used transcriptome sequencing, the GCBI bioinformatics database and the STRING database to predict relevant target proteins. Furthermore, pathological sections were collected from relevant cases for immunohistochemical verification.

RESULTS

This study showed that atovaquone could inhibit colorectal cancer metastasis and invasion in vivo and in vitro, inhibit the expression of E-cadherin protein, and promote the protein expression of N-cadherin, vimentin, ZEB1, Snail and Slug. Atovaquone could inhibit EMT by inhibiting NF-κB (p-P65) and related inflammatory factors. Further bioinformatics analysis and verification showed that PDGFRβ was one of the targets of atovaquone.

CONCLUSION

In summary, atovaquone can inhibit the expression of NF-κB (p-P65) and related inflammatory factors by inhibiting the protein expression of p-PDGFRβ, thereby inhibiting colorectal cancer metastasis. Atovaquone may be a promising drug for the treatment of colorectal cancer metastasis.

Initial drainage‐related prognostic factors for perihilar cholangiocarcinoma: A single‐center retrospective study

Objectives

Perihilar cholangiocarcinoma (PCC) is a complex disorder involving the hepatic hilum. Multiple endoscopic retrograde cholangiopancreatography sessions are necessary for diagnosis and treatment with underlying cholangitis risk. Our aim is to clarify the initial‐drainage‐related prognostic factors of PCC.

Methods

This study was a single‐center retrospective study. A total of 104 consecutive patients diagnosed with PCC from January 2010 to February 2020 were enrolled. We defined the diagnostic period as the time between the first biliary drainage attempt and the final drainage when treatment, including surgery or chemotherapy, was started. We focused on this initial period and analyzed the endoscopy‐related factors that affected mortality.

Results

Overall survival of all PCC patients was 599 days. Overall survival of surgically treated patients and unresectable patients were 893 days and 512 days, respectively. In 48 surgically treated patients, drainage‐related cholangitis within the diagnostic period, defined as new cholangitis that occurred after the first biliary drainage attempt, worsened overall survival from 1460 days to 607 days. Endoscopic sphincterotomy, the first drainage method other than endoscopic nasobiliary drainage, and four or more endoscopic retrograde cholangiopancreatography sessions were risk factors for drainage‐related cholangitis. Drainage‐related cholangitis increased pathological lymph node metastasis. Percutaneous transhepatic biliary drainage as final drainage was the only prognostic factor in unresectable chemotherapy‐treated patients.

Conclusions

Drainage‐related cholangitis worsened the prognosis in PCC patients who underwent surgery. Appropriate endoscopic retrograde cholangiopancreatography strategies, especially during the diagnostic period, are of great importance in PCC.

IFIT2 Depletion Promotes Cancer Stem Cell-like Phenotypes in Oral Cancer

(1) Background: Cancer stem cells (CSCs) are a small cell population associated with chemoresistance, metastasis and increased mortality rate in oral cancer. Interferon-induced proteins with tetratricopeptide repeats 2 (IFIT2) depletion results in epithelial to mesenchymal transition, invasion, metastasis, and chemoresistance in oral cancer. To date, no study has demonstrated the effect of IFIT2 depletion on the CSC-like phenotype in oral cancer cells. (2) Methods: Q-PCR, sphere formation, Hoechst 33,342 dye exclusion, immunofluorescence staining, and flow cytometry assays were performed to evaluate the expression of the CSC markers in IFIT2-depleted cells. A tumorigenicity assay was adopted to assess the tumor formation ability. Immunohistochemical staining was used to examine the protein levels of IFIT2 and CD24 in oral cancer patients. (3) Results: The cultured IFIT2 knockdown cells exhibited an overexpression of ABCG2 and CD44 and a downregulation of CD24 and gave rise to CSC-like phenotypes. Clinically, there was a positive correlation between IFIT2 and CD24 in the patients. IFIT2high/CD24high/CD44low expression profiles predicted a better prognosis in HNC, including oral cancer. The TNF-α blockade abolished the IFIT2 depletion-induced sphere formation, indicating that TNF-α may be involved in the CSC-like phenotypes in oral cancer. (4) Conclusions: The present study demonstrates that IFIT2 depletion promotes CSC-like phenotypes in oral cancer.

The contradictory roles of macrophages in non-alcoholic fatty liver disease and primary liver cancer-Challenges and opportunities

Chronic liver diseases from varying etiologies generally lead to liver fibrosis and cirrhosis. Among them, non-alcoholic fatty liver disease (NAFLD) affects roughly one-quarter of the world population, thus representing a major and increasing public health burden. Chronic hepatocyte injury, inflammation (non-alcoholic steatohepatitis, NASH) and liver fibrosis are recognized soils for primary liver cancer, particularly hepatocellular carcinoma (HCC), being the third most common cause for cancer-related deaths worldwide. Despite recent advances in liver disease understanding, therapeutic options on pre-malignant and malignant stages remain limited. Thus, there is an urgent need to identify targetable liver disease-driving mechanisms for the development of novel therapeutics. Monocytes and macrophages comprise a central, yet versatile component of the inflammatory response, fueling chronic liver disease initiation and progression. Recent proteomic and transcriptomic studies performed at singular cell levels revealed a previously overlooked diversity of macrophage subpopulations and functions. Indeed, liver macrophages that encompass liver resident macrophages (also named Kupffer cells) and monocyte-derived macrophages, can acquire a variety of phenotypes depending on microenvironmental cues, and thus exert manifold and sometimes contradictory functions. Those functions range from modulating and exacerbating tissue inflammation to promoting and exaggerating tissue repair mechanisms (i.e., parenchymal regeneration, cancer cell proliferation, angiogenesis, fibrosis). Due to these central functions, liver macrophages represent an attractive target for the treatment of liver diseases. In this review, we discuss the multifaceted and contrary roles of macrophages in chronic liver diseases, with a particular focus on NAFLD/NASH and HCC. Moreover, we discuss potential therapeutic approaches targeting liver macrophages.

Tumor microenvironment enriches the stemness features: the architectural event of therapy resistance and metastasis

Cancer divergence has many facets other than being considered a genetic term. It is a tremendous challenge to understand the metastasis and therapy response in cancer biology; however, it postulates the opportunity to explore the possible mechanism in the surrounding tumor environment. Most deadly solid malignancies are distinctly characterized by their tumor microenvironment (TME). TME consists of stromal components such as immune, inflammatory, endothelial, adipocytes, and fibroblast cells. Cancer stem cells (CSCs) or cancer stem-like cells are a small sub-set of the population within cancer cells believed to be a responsible player in the self-renewal, metastasis, and therapy response of cancer cells. The correlation between TME and CSCs remains an enigma in understanding the events of metastasis and therapy resistance in cancer biology. Recent evidence suggests that TME dictates the CSCs maintenance to arbitrate cancer progression and metastasis. The immune, inflammatory, endothelial, adipocyte, and fibroblast cells in the TME release growth factors, cytokines, chemokines, microRNAs, and exosomes that provide cues for the gain and maintenance of CSC features. These intricate cross-talks are fueled to evolve into aggressive, invasive, migratory phenotypes for cancer development. In this review, we have abridged the recent developments in the role of the TME factors in CSC maintenance and how these events influence the transition of tumor progression to further translate into metastasis and therapy resistance in cancer.

The mechanism of lncRNAs in the crosstalk between epithelial-mesenchymal transition and tumor microenvironment for early colon adenocarcinoma based on molecular subtyping

A large number of colon adenocarcinoma (COAD) patients are already advanced when diagnosed. In this study, we aimed to further understand the mechanism of tumor development in early COAD by focusing on epithelial-mesenchymal transition (EMT) and long non-coding RNAs (lncRNAs). Expression profiles of early COAD patients were obtained from public databases. EMT-related lncRNAs were used as a basis for constructing molecular subtypes through unsupervised consensus clustering. Genomic features, pathways and tumor microenvironment (TME) were compared between two subtypes. LncATLAS database was applied to analyze the relation between lncRNAs and transcription factors (TFs). First order partial correlation analysis was conducted to identify key EMT-related lncRNAs.C1 and C2 subtypes with distinct prognosis were constructed. Oncogenic pathways such as EMT, KRAS signaling, JAK-STAT signaling, and TGF-β signaling were significantly enriched in C2 subtype. Higher immune infiltration and expression of immune checkpoints were also observed in C2 subtype, suggesting the key EMT-related lncRNAs may play a critical role in the modulation of TME. In addition, JAK-STAT signaling pathway was obviously enriched in upregulated TFs in C2 subtype, which indicated a link between key lncRNAs and JAK-STAT signaling that may regulate TME. The study further expanded the research on the role of EMT-related lncRNAs in the early COAD. The six identified EMT-related lncRNAs could serve as biomarkers for early screening COAD.

Berberine as a potential agent for breast cancer therapy

Breast cancer (BC) is a common malignancy that mainly occurred in women and it has become the most diagnosed cancer annually since 2020. Berberine (BBR), an alkaloid extracted from the Berberidacea family, has been found with broad pharmacological bioactivities including anti-inflammatory, anti-diabetic, anti-hypertensive, anti-obesity, antidepressant, and anticancer effects. Mounting evidence shows that BBR is a safe and effective agent with good anticancer activity against BC. However, its detailed underlying mechanism in BC treatment remains unclear. Here, we will provide the evidence for BBR in BC therapy and summarize its potential mechanisms. This review briefly introduces the source, metabolism, and biological function of BBR and emphasizes the therapeutic effects of BBR against BC via directly interacting with effector proteins, transcriptional regulatory elements, miRNA, and several BBR-mediated signaling pathways. Moreover, the novel BBR-based therapeutic strategies against BC improve biocompatibility and water solubility, and the efficacies of BBR are also briefly discussed. Finally, the status of BBR in BC treatment and future research directions is also prospected.

Similarities and differences among the Opisthorchiidae liver flukes: insights from Opisthorchis felineus

The foodborne liver trematode Opisthorchis felineus (Rivolta, 1884) is a member of the triad of phylogenetically related epidemiologically important Opisthorchiidae trematodes, which also includes O. viverrini (Poirier, 1886) and Clonorchis sinensis (Loos, 1907). Despite similarity in the life cycle, Opisthorchiidae liver flukes also have marked differences. Two species (O. viverrini and C. sinensis) are recognized as Group 1A biological carcinogens, whereas O. felineus belongs to Group 3A. In this review, we focus on these questions: Are there actual differences in carcinogenicity among these 3 liver fluke species? Is there an explanation for these differences? We provide a recent update of our knowledge on the liver fluke O. felineus and highlight its differences from O. viverrini and C. sinensis. In particular, we concentrate on differences in the climate of endemic areas, characteristics of the life cycle, the range of intermediate hosts, genomic and transcriptomic features of the pathogens, and clinical symptoms and morbidity of the infections in humans. The discussion of these questions can stimulate new developments in comparative studies on the pathogenicity of liver flukes and should help to identify species-specific features of opisthorchiasis and clonorchiasis pathogenesis.

A comparative study on the model of PM2.5 direct or indirect interaction with bronchial epithelial cells

The impact of PM_2.5 on epithelial cells is a pivotal process leading to many lung pathological changes and pulmonary diseases. In addition to PM_2.5 direct interaction with epithelia, macrophages that engulf PM_2.5 may also influence the function of epithelial cells. However, among the toxic researches of PM_2.5, there is a lack of evaluation of direct or indirect exposure model on human bronchial epithelial cell against PM_2.5. In this present research, PM_2.5-exposed human bronchial epithelial cell line (BEAS-2B) serves as the direct interaction model. By contrast, a PM_2.5-stimulated co-culture model of macrophages and epithelial cells based on the transwell system was adopted as indirect stimulation model. By comparing these two models of interaction, we examined the viability of BEAS-2B and mRNA/protein expression profile of oxidative stress and inflammatory response-related transcription factors Nrf2, NF-kB, and according inflammatory indicators such as IL-1, IL-6, and IL-8, with a view to evaluating the effects of different interaction models of PM_2.5 on epithelial cell damage in vitro. Our results indicated that under the same doses, the direct stimulation model of PM_2.5 could inhibit the viability of BEAS-2B. Furthermore, the indirect stimulation model strengthen inflammation response of epithelia under the higher concentration of PM_2.5 and induce epithelia to undergo EMT under the lower concentration of PM_2.5. Overall, we have found that macrophage involvement may protect epithelia from PM_2.5 cytotoxic effect, while it strengthens the inflammation response and induce epithelia to undergo EMT.

Metformin suppressed tumor necrosis factor-α-induced epithelial-mesenchymal transition in prostate cancer by inactivating the NF-κB signaling pathway

BACKGROUND

Epithelial-mesenchymal transition (EMT) and the tumor micro- environment are involved in tumorigenesis and progression. Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine in cancer that might be associated with promoting cancer invasion and metastasis. This study aimed to explore the potential effects of metformin on TNF-α-induced EMT in prostate cancer.

METHODS

TNF-α, NF-κB-P65 and E-cadherin were detected in prostate cancer and benign prostatic hyperplasia (BPH) tissues by immunohistochemistry. Prostate cancer PC3 cells were treated with TNF-α with or without metformin. Then, the cell invasion and cell proliferation ability was separately determined by scratch assay and invasion assay. The expression of E-cadherin, N-cadherin, Vimentin, TNF-α, NF-κB-P65, p-IKK and p-IκBα were detected by western blotting and immunofluorescence.

RESULTS

TNF-α and NF-κB-P65 were positively related to higher Gleason scores, but E-cadherin was negatively related to higher Gleason scores. TNF-α significantly increased the migration and invasion ability of prostate cancer cells, and it significantly promoted the expression of N-cadherin, Vimentin, NF-κB-P65, p-IKK and p-IκBα but reduced the expression of E-cadherin. Metformin significantly inhibited TNF-α-induced migration and invasion of prostate cancer cells. Furthermore, metformin decreased TNF-α-induced expression of N-cadherin, Vimentin, NF-κB-P65, p-IKK and p-IκBα but increased the expression of E-cadherin. Moreover, metformin inhibited NF-κB-P65 translocation into the nucleus.

CONCLUSIONS

TNF-α accelerated the EMT process potentially via activation of the NF-κB signaling pathway. Metformin might suppress TNF-α-induced EMT in prostate cancer by inactivating the NF-κB signaling pathway.

Thymidine phosphorylase promotes angiogenesis and tumour growth in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer, and thymidine phosphorylase (TP) is a regulator of angiogenesis. To investigate the biological activities of TP in ICC, we established human cholangiocarcinoma RBE cell lines overexpressing TP or silencing TP. Overexpression of TP enhanced viability, suppressed apoptosis and increased tube formation in human umbilical vein endothelial cells, while downregulation of TP reversed these effects. Moreover, an orthotopic xenograft mouse model of ICC was built to further explore TP's function in ICC in vivo. Histological analysis using H&E, TUNEL and Ki67 staining showed that TP promoted tumour growth and inhibited cell apoptosis. Immunostaining for CD31 revealed an elevation in microvessel density in the presence of TP. Besides, upregulation of TP increased the expression of vascular endothelial growth factor, basic fibroblast growth factor, interleukin-8 and tumour necrosis factor alpha. In contrast, TP knockdown inhibited tumour growth, suppressed microvessel formation and decreased the expression of angiogenesis-related proteins. Therefore, we suggest that TP promotes angiogenesis and tumour growth in ICC, which can be a potent therapeutic target for ICC treatment.

Periostin induces epithelial‑to‑mesenchymal transition via the integrin α5β1/TWIST‑2 axis in cholangiocarcinoma

Periostin (PN) (also known as osteoblast-specific factor OSF-2) is a protein that in humans is encoded by the POSTN gene and has been correlated with a reduced survival of cholangiocarcinoma (CCA) patients, with the well-known effect of inducing epithelial-to-mesenchymal transition (EMT). The present study investigated the effect of PN, through integrin (ITG)α5β1, in EMT-mediated CCA aggressiveness. The alterations in EMT-related gene and protein expression were investigated by real-time PCR, western blot analysis and zymogram. The effects of PN on migration and the level of TWIST-2 were assessed in CCA cells with and without siITGα5 transfection. PN was found to induce CCA cell migration and EMT features, including increments in Twist-related protein 2 (TWIST-2), zinc finger protein SNAI1 (SNAIL-1), α-smooth muscle actin (ASMA), vimentin (VIM) and matrix metallopeptidase 9 (MMP-9), and a reduction in cytokeratin 19 (CK-19) together with cytoplasmic translocation of E-cadherin (CDH-1). Additionally, PN markedly induced MMP-9 activity. TWIST-2 was significantly induced in PN-treated CCA cells; this effect was attenuated in the ITGα5β1-knockdown cells and corresponded to reduced migration of the cancer cells. These results indicated that PN induced CCA migration through ITGα5β1/TWIST-2-mediated EMT. Moreover, clinical samples from CCA patients showed that higher levels of TWIST-2 were significantly correlated with shorter survival time. In conclusion, the ITGα5β1-mediated TWIST-2 signaling pathway regulates PN-induced EMT in CCA progression, and TWIST-2 is a prognostic marker of poor survival in CCA patients.

PM2.5, Fine Particulate Matter: A Novel Player in the Epithelial-Mesenchymal Transition?

Epithelial-mesenchymal transition (EMT) refers to the conversion of epithelial cells to mesenchymal phenotype, which endows the epithelial cells with enhanced migration, invasion, and extracellular matrix production abilities. These characteristics link EMT with the pathogenesis of organ fibrosis and cancer progression. Recent studies have preliminarily established that fine particulate matter with an aerodynamic diameter of less than 2.5 μm (PM_2.5) is correlated with EMT initiation. In this pathological process, PM_2.5 particles, excessive reactive oxygen species (ROS) derived from PM_2.5, and certain components in PM_2.5, such as ions and polyaromatic hydrocarbons (PAHs), have been implicated as potential EMT mediators that are linked to the activation of transforming growth factor β (TGF-β)/SMADs, NF-κB, growth factor (GF)/extracellular signal-regulated protein kinase (ERK), GF/phosphatidylinositol 3-kinase (PI3K)/Akt, wingless/integrated (Wnt)/β-catenin, Notch, Hedgehog, high mobility group box B1 (HMGB1)-receptor for advanced glycation end-products (RAGE), and aryl hydrocarbon receptor (AHR) signaling cascades and to cytoskeleton rearrangement. These pathways directly and indirectly transduce pro-EMT signals that regulate EMT-related gene expression in epithelial cells, finally inducing the characteristic alterations in morphology and functions of epithelia. In addition, novel associations between autophagy, ATP citrate lyase (ACLY), and exosomes with PM_2.5-induced EMT have also been summarized. However, some debates and paradoxes remain to be consolidated. This review discusses the potential molecular mechanisms underlying PM_2.5-induced EMT, which might account for the latent role of PM_2.5 in cancer progression and fibrogenesis.

Role of Cancer Stem Cells in Cholangiocarcinoma and Therapeutic Implications

Cholangiocarcinoma (CCA) is the second most common type of liver cancer, and is highly aggressive with very poor prognosis. CCA is classified into intrahepatic cholangiocarcinoma (iCCA) and extra-hepatic cholangiocarcinoma (eCCA), which is further stratified into perihilar (pCCA) and distal (dCCA). Cancer stem cells (CSCs) are a subpopulation of cancer cells capable of tumor initiation and malignant growth, and are also responsible for chemoresistance. Thus, CSCs play an important role in CCA carcinogenesis. Surface markers such as CD133, CD24, CD44, EpCAM, Sox2, CD49f, and CD117 are important for identifying and isolating CCA CSCs. CSCs are present in the tumor microenvironment (TME), termed ‘CSC niche’, where cellular components and soluble factors interact to promote tumor initiation. Epithelial-to-mesenchymal transition (EMT) is another important mechanism underlying carcinogenesis, involved in the invasiveness, metastasis and chemoresistance of cancer. It has been demonstrated that EMT plays a critical role in generating CSCs. Therapies targeting the surface markers and signaling pathways of CCA CSCs, proteins involved in TME, and immune checkpoint proteins are currently under investigation. Therefore, this review focuses on recent studies on the roles of CSCs in CCA; the possible therapeutic strategies targeting CSCs of CCA are also discussed.

Melatonin preconditioning of bone marrow-derived mesenchymal stem cells promotes their engraftment and improves renal regeneration in a rat model of chronic kidney disease

Bone marrow-derived mesenchymal stem cells (BMMSCs) transplantation has shown to be effective in treating chronic kidney disease. However, the effectiveness of this strategy is constrained by low homing and survival rate of transplanted cells in the injured organs. Therefore, developing strategies to improve homing and cell survival rate and therapeutic potential in cell-based therapies seems necessary. The purpose of this study is to evaluate the effect of pretreating BMMSCs with melatonin (MT) on the prosurvival and renoprotective of transplanted cells into the irreversible model of unilateral ureteral obstruction. Adult male Sprague-Dawley rats were randomized into four groups: Sham, UUO, UUO + BMMSCs, and UUO + BMMSCs + MT. The results of our study demonstrated that preconditioning with MT enhanced homing of BMMSCs into the injured kidney. MT reduced the number of TUNEL positive transplanted cells in the UUO + BMMSCs + MT group. The UUO + BMMSCs + MT group showed lower expressions of TGF-β1, α-SMA and TNF-α at both gene and protein levels but higher expression of E-cadherin compared with the UUO + BMMSCs group. In addition, MT preconditioned BMMSCs ameliorated basement membrane disruption and histological status of injured renal tubules and also reduced fibrosis in damaged kidneys. In conclusion, our results show that stem cells pretreated by MT may represent a feasible approach for improving the beneficial effects of stem cell therapy and significantly enhance their survival after transplantation to the injured kidney.

The role of tumour microenvironment: a new vision for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a relatively rare malignant and lethal tumour derived from bile duct epithelium and the morbidity is now increasing worldwide. This disease is difficult to diagnose at its inchoate stage and has poor prognosis. Therefore, a clear understanding of pathogenesis and major influencing factors is the key to develop effective therapeutic methods for CCA. In previous studies, canonical correlation analysis has demonstrated that tumour microenvironment plays an intricate role in the progression of various types of cancers including CCA. CCA tumour microenvironment is a dynamic environment consisting of authoritative tumour stromal cells and extracellular matrix where tumour stromal cells and cancer cells can thrive. CCA stromal cells include immune and non‐immune cells, such as inflammatory cells, endothelial cells, fibroblasts, and macrophages. Likewise, CCA tumour microenvironment contains abundant proliferative factors and can significantly impact the behaviour of cancer cells. Through abominably intricate interactions with CCA cells, CCA tumour microenvironment plays an important role in promoting tumour proliferation, accelerating neovascularization, facilitating tumour invasion, and preventing tumour cells from organismal immune reactions and apoptosis. This review summarizes the recent research progress regarding the connection between tumour behaviours and tumour stromal cells in CCA, as well as the mechanism underlying the effect of tumour stromal cells on the growth of CCA. A thorough understanding of the relationship between CCA and tumour stromal cells can shed some light on the development of new therapeutic methods for treating CCA.

Ponicidin inhibits pro-inflammatory cytokine TNF-α-induced epithelial-mesenchymal transition and metastasis of colorectal cancer cells via suppressing the AKT/GSK-3β/Snail pathway

Ponicidin (PON), a natural diterpenoid compound, has been shown to exhibit potent anticancer activities in a wide variety of cancers, including colorectal cancer (CRC). Nevertheless, the precise mechanisms underlying the anti-metastasis effect of PON have not yet been completely defined. The present study was designed to uncover the inhibitory effect of PON on epithelial-mesenchymal transition (EMT), migration and invasion of HCT116 cells induced by pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) in vitro, and liver metastasis in vivo. Briefly, cell proliferation was assessed by Cell Counting Kit-8 assay, followed by wound healing and transwell assays to evaluate cell migration and invasion. The EMT-related molecular markers were determined through quantitative real-time polymerase chain reaction (qPCR), immunofluorescence (IF), western blot (WB), and immunohistochemistry (IHC). Additionally, WB was used to assess the expression of AKT, phosphorylated AKT (p-AKT), GSK-3β, and phosphorylated GSK-3β (p-GSK-3β). As a result, PON could effectively suppress EMT, migration, and invasion in HCT116 cells in vitro, and liver metastasis of HCT116 cells in vivo. Additionally, PON administration also dramatically altered the expression of EMT-associated markers such as E-cadherin, N-cadherin, and Vimentin, and suppressed the expression of p-AKT, p-GSK-3β and transcription factor, Snail in a dose-dependent manner. Moreover, the incidence of liver metastasis in the control group was 100% and although the incidence of liver metastasis did not decrease, the number of metastatic nodules in the livers of each PON dose group decreased by (34 ± 4.2)%, (64 ± 3.6)%, and (76 ± 5.3)%, respectively, compared to the control group. Collectively, these findings indicated that targeting the AKT/GSK-3β/Snail pathway by PON might be a promising treatment for TNF-α-induced EMT and metastasis of CRC.

Relationship between epithelial-to-mesenchymal transition and the inflammatory microenvironment of hepatocellular carcinoma

Epithelial-to-mesenchymal transition (EMT) is a complex process involving multiple genes, steps and stages. It refers to the disruption of tight intercellular junctions among epithelial cells under specific conditions, resulting in loss of the original polarity, order and consistency of the cells. Following EMT, the cells show interstitial cell characteristics with the capacity for adhesion and migration, while apoptosis is inhibited. This process is critically involved in embryogenesis, wound-healing, tumor invasion and metastasis. The tumor microenvironment is composed of infiltrating inflammatory cells, stromal cells and the active medium secreted by interstitial cells. Most patients with hepatocellular carcinoma (HCC) have a history of hepatitis virus infection. In such cases, major components of the tumor microenvironment include inflammatory cells, inflammatory factors and virus-encoded protein are major components. Here, we review the relationship between EMT and the inflammatory tumor microenvironment in the context of HCC. We also further elaborate the significant influence of infiltrating inflammatory cells and inflammatory mediators as well as the products expressed by the infecting virus in the tumor microenvironment on the EMT process.

Opisthorchiasis with proinflammatory cytokines (IL-1β and TNF-α) polymorphisms influence risk of intrahepatic cholangiocarcinoma in Thailand: a nested case-control study

Background

Chronic inflammation and repeated infection with Opisthorchis viverrini (O. viverrini) induces intrahepatic cholangiocarcinoma (ICC). Inflammatory cytokines such as interleukin (IL) and tumor necrosis factor (TNF) are substances in the immune system that promote inflammation and causes disease to progress. Genes that help express proinflammatory cytokines can affect an individual’s susceptibility to disease, especially in cancer-related chronic inflammation. This study aimed to investigate risk factors for ICC with a focus on opisthorchiasis and polymorphisms of proinflammatory cytokines (IL-1β and TNF-α).

Methods

This study was a nested case-control study within a cohort study. 219 subjects who developed a primary ICC were identified and matched with two non-cancer controls from the same cohort based on sex and age at recruitment (±3 years). An O. viverrini-IgG antibody was assessed using enzyme linked immunosorbent assay. IL-1β and TNF-α polymorphisms were analyzed using a polymerase chain reaction with high resolution melting analysis. Associations between variables and ICC were assessed using conditional logistic regression.

Results

Subjects with a high infection intensity had higher risk of ICC than those who had a low level (OR = 2.1; 95% CI: 1.2–3.9). Subjects with all genotypes of TNF-α (GG, GA, AA) and high infection intensity were significantly related to an increased risk of ICC (p < 0.05).

Conclusions

Polymorphisms of IL-1β and TNF-α are not a risk of ICC, but an individual with O. viverrini infection has an effect on all genotypes of the TNF-α gene that might promote ICC. Primary prevention of ICC in high-risk areas is based on efforts to reduce O. viverrini infection.

Cancer; an induced disease of twentieth century! Induction of tolerance, increased entropy and 'Dark Energy': loss of biorhythms (Anabolism v. Catabolism)

Maintenance of health involves a synchronized network of catabolic and anabolic signals among organs/tissues/cells that requires differential bioenergetics from mitochondria and glycolysis (biological laws or biorhythms). We defined biological circadian rhythms as Yin (tumoricidal) and Yang (tumorigenic) arms of acute inflammation (effective immunity) involving immune and non-immune systems. Role of pathogens in altering immunity and inducing diseases and cancer has been documented for over a century. However, in 1955s decision makers in cancer/medical establishment allowed public (current baby boomers) to consume million doses of virus-contaminated polio vaccines. The risk of cancer incidence and mortality sharply rose from 5% (rate of hereditary/genetic or innate disease) in 1900s, to its current scary status of 33% or 50% among women and men, respectively. Despite better hygiene, modern detection technologies and discovery of antibiotics, baby boomers and subsequent 2–3 generations are sicker than previous generations at same age. American health status ranks last among other developed nations while America invests highest amount of resources for healthcare. In this perspective we present evidence that cancer is an induced disease of twentieth century, facilitated by a great deception of cancer/medical establishment for huge corporate profits. Unlike popularized opinions that cancer is 100, 200 or 1000 diseases, we demonstrate that cancer is only one disease; the severe disturbances in biorhythms (differential bioenergetics) or loss of balance in Yin and Yang of effective immunity. Cancer projects that are promoted and funded by decision makers are reductionist approaches, wrong and unethical and resulted in loss of millions of precious lives and financial toxicity to society. Public vaccination with pathogen-specific vaccines (e.g., flu, hepatitis, HPV, meningitis, measles) weakens, not promotes, immunity. Results of irresponsible projects on cancer sciences or vaccines are increased population of drug-dependent sick society. Outcome failure rates of claimed ‘targeted’ drugs, ‘precision’ or ‘personalized’ medicine are 90% (± 5) for solid tumors. We demonstrate that aging, frequent exposures to environmental hazards, infections and pathogen-specific vaccines and ingredients are ‘antigen overload’ for immune system, skewing the Yin and Yang response profiles and leading to induction of ‘mild’, ‘moderate’ or ‘severe’ immune disorders. Induction of decoy or pattern recognition receptors (e.g., PRRs), such as IRAK-M or IL-1dRs (‘designer’ molecules) and associated genomic instability and over-expression of growth promoting factors (e.g., pyruvate kinases, mTOR and PI3Ks, histamine, PGE2, VEGF) could lead to immune tolerance, facilitating cancer cells to hijack anabolic machinery of immunity (Yang) for their increased growth requirements. Expression of constituent embryonic factors would negatively regulate differentiation of tumor cells through epithelial–mesenchymal-transition and create “dual negative feedback loop” that influence tissue metabolism under hypoxic conditions. It is further hypothesized that induction of tolerance creates ‘dark energy’ and increased entropy and temperature in cancer microenvironment allowing disorderly cancer proliferation and mitosis along with increased glucose metabolism via Crabtree and Pasteur Effects, under mitophagy and ribophagy, conditions that are toxic to host survival. Effective translational medicine into treatment requires systematic and logical studies of complex interactions of tumor cells with host environment that dictate clinical outcomes. Promoting effective immunity (biological circadian rhythms) are fundamental steps in correcting host differential bioenergetics and controlling cancer growth, preventing or delaying onset of diseases and maintaining public health. The author urges independent professionals and policy makers to take a closer look at cancer dilemma and stop the ‘scientific/medical ponzi schemes’ of a powerful group that control a drug-dependent sick society before all hopes for promoting public health evaporate.

Interplay between inflammatory tumor microenvironment and cancer stem cells

Cancer stem cells (CSCs), which have a close connection with tumor microenvironment, play a pivotal role in tumorigenesis, tumor progression, and metastasis. The inflammatory microenvironment is an essential component of tumor microenvironment. In the recent years, many studies have demonstrated that the inflammatory microenvironment induces the initiation of tumors, and contributes to the process of the progression of tumors, as well as metastasis. In this review, we summarize the relationship between CSCs and inflammatory components, such as inflammatory cytokines (IFNs, TNF, IL-6, IL-17) and inflammatory cells (myeloid-derived suppressor cells, tumor-associated macrophages). To illuminate the key factors that exert important actions in the tumor process would be important to improve the clinical outcome of the treatment for different types of cancer.

Molecular Mechanisms Driving Cholangiocarcinoma Invasiveness: An Overview

The acquisition of invasive functions by tumor cells is a first and crucial step toward the development of metastasis, which nowadays represents the main cause of cancer-related death. Cholangiocarcinoma (CCA), a primary liver cancer originating from the biliary epithelium, typically develops intrahepatic or lymph node metastases at early stages, thus preventing the majority of patients from undergoing curative treatments, consistent with their very poor prognosis. As in most carcinomas, CCA cells gradually adopt a motile, mesenchymal-like phenotype, enabling them to cross the basement membrane, detach from the primary tumor, and invade the surrounding stroma. Unfortunately, little is known about the molecular mechanisms that synergistically orchestrate this proinvasive phenotypic switch. Autocrine and paracrine signals (cyto/chemokines, growth factors, and morphogens) permeating the tumor microenvironment undoubtedly play a prominent role in this context. Moreover, a number of recently identified signaling systems are currently drawing attention as putative mechanistic determinants of CCA cell invasion. They encompass transcription factors, protein kinases and phosphatases, ubiquitin ligases, adaptor proteins, and miRNAs, whose aberrant expression may result from either stochastic mutations or the abnormal activation of upstream pro-oncogenic pathways. Herein we sought to summarize the most relevant molecules in this field and to discuss their mechanism of action and potential prognostic relevance in CCA. Hopefully, a deeper knowledge of the molecular determinants of CCA invasiveness will help to identify clinically useful biomarkers and novel druggable targets, with the ultimate goal to develop innovative approaches to the management of this devastating malignancy.

Roles of TNF-α/NF-κB/Snail pathway in regulating epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is a process of transformation of epithelial cells to mesenchymal cells, and it not only plays an important role in the developmental process, but also participates in tissue healing, organ fibrosis, tumorigenesis, and metastasis. In recent years, it has been found that tumor necrosis factor-α (TNF-α) is a major inflammatory factor that can induce snail expression by binding to nuclear factor-κB (NF-κB), thus mediating EMT. This article briefly introduces the roles of the TNF-α/NF-κB/Snail pathway in mediating EMT, aiming to promote a further understanding of the mechanism of TNF-α in regulating EMT.

Progranulin modulates cholangiocarcinoma cell proliferation, apoptosis, and motility via the PI3K/pAkt pathway

Progranulin (PGRN) is a growth factor normally expressed in rapidly cycling epithelial cells for growth, differentiation, and motility. Several studies have shown the association of PGRN overexpression with the progression of numerous malignancies, including cholangiocarcinoma (CCA). However, the underlying mechanisms on how PGRN modulates CCA cell proliferation and motility is not clear. In this study, we investigated the prognostic significance of PGRN expression in human CCA tissue and the mechanisms of PGRN modulation of CCA cell proliferation and motility. We found that CCA tissues with high PGRN expression were correlated with poor prognosis and likelihood of metastasis. PGRN knockdown KKU-100 and KKU-213 cells demonstrated a reduced rate of proliferation and colony formation and decreased levels of phosphatidyl inositol-3-kinase (PI3K) and phosphorylated Akt (pAkt) proteins. Accumulation of cells at the G1 phase was observed and was accompanied by a reduction of cyclin D1 and CDK4 protein levels. Knockdown cells also induced apoptosis by increasing the Bax-to-Bcl-2 ratio. Increased cell apoptosis was confirmed by annexin V-FITC/PI staining. Moreover, suppression of PGRN reduced CCA cell migration and invasion in vitro. Investigating the biomarkers in epithelial–mesenchymal transition (EMT) revealed a decrease in the expression of vimentin, snail, and metalloproteinase-9. In conclusion, our findings imply that PGRN modulates cell proliferation by dysregulating the G1 phase, inhibiting apoptosis, and that it plays a role in the EMT affecting CCA cell motility, possibly via the PI3K/pAkt pathway.

Is Osteopontin a Friend or Foe of Cell Apoptosis in Inflammatory Gastrointestinal and Liver Diseases?

Osteopontin (OPN) is involved in a variety of biological processes, including bone remodeling, innate immunity, acute and chronic inflammation, and cancer. The expression of OPN occurs in various tissues and cells, including intestinal epithelial cells and immune cells such as macrophages, dendritic cells, and T lymphocytes. OPN plays an important role in the efficient development of T helper 1 immune responses and cell survival by inhibiting apoptosis. The association of OPN with apoptosis has been investigated. In this review, we described the role of OPN in inflammatory gastrointestinal and liver diseases, focusing on the association of OPN with apoptosis. OPN changes its association with apoptosis depending on the type of disease and the phase of disease activity, acting as a promoter or a suppressor of inflammation and inflammatory carcinogenesis. It is essential that the roles of OPN in those diseases are elucidated, and treatments based on its mechanism are developed.

Genistein induces apoptosis of colon cancer cells by reversal of epithelial-to-mesenchymal via a Notch1/NF-κB/slug/E-cadherin pathway

Background

Genistein has been known to inhibit proliferation and induce apoptosis in several kinds of cancer cells. While knowledge of genistein in regulating epithelial mesenchymal transition (EMT) of colon cancer cells is unknown.

Methods

To investigate the effects and mechanisms of genistein on EMT of colon cancer cells, HT-29 cells were used and treated by genistein and TNF-α in this paper. EMT was determined by cell invasion assays using a transwell chamber and the expression changes of EMT-related markers were confirmed by RT–PCR, Western blotting, and immunofluorescence staining.

Results

Genistein inhibited cell migration at 200 μmol/L. Genistein reversed the EMT of colon cancer cells by upregulation of E-cadherin and downregulation of N-cadherin, accompanied by the suppression of EMT related makers, such as Snail2/slug, ZEB1, ZEB2, FOXC1, FOXC2 and TWIST1. Moreover, genistein can inhibit the expression of notch-1, p-NF-κB and NF-κB, while promote the expression of Bax/Bcl-2 and caspase-3 in HT-29 cells.

Conclusion

The present study demonstrated that genistein suppressed the migration of colon cancer cells by reversal the EMT via suppressing the Notch1/NF-κB/slug/E-cadherin pathway. Genistein may be developed as a potential antimetastasis agent to colon cancer.

Role of tumor necrosis factor-α in epithelial-to-mesenchymal transition in transplanted kidney cells in recipients with chronic allograft dysfunction

BACKGROUND

Chronic allograft dysfunction (CAD) is characterized by allograft kidney interstitial fibrosis, the underlying mechanism of which is unclear. Our aim was to elucidate the role and mechanism of TNF-α-induced epithelial-to-mesenchymal transition (EMT) in transplant kidney tubular interstitial fibrosis.

METHODS

Human kidney tissues from normal volunteers and CAD patients were assessed using periodic acid-Schiff, Masson trichrome and immunohistochemical staining. mRNA and protein expression of E-cadherin, α-smooth muscle actin (SMA) and fibronectin(FN) in renal proximal tubule epithelial (HK-2) cells after treatment with TNF-α under different conditions were assessed using western blot and qRT-PCR analysis. Cell motility and migration were assessed using wound healing and transwell assays. Expression of Smurf2 and TNF-α-signaling pathway-related proteins in HK-2 cells treated with TNF-α was detected by western blotting. E-cadherin and α-SMA expression was also assessed in Smurf2 plasmid-transfected or Smurf2 siRNA-treated HK-2 cells.

RESULTS

The expression of TNF-α, Smurf2, α-SMA, and fibronectin was significantly upregulated, while the expression of E-cad was downregulated in the CAD group compared with the normal group. The in vitro results showed that TNF-α remarkably upregulated the expression of Smurf2, α-SMA and fibronectin and downregulated the expression of E-cadherin in HK-2 cells and enhanced motility and migration in HK-2 cells. Overexpression of Smurf2 could promote the expression of α-SMA and inhibit the expression of E-cad, whereas knockdown of Smurf2 expression reversed TNF-α-induced upregulation of α-SMA and prohibited the reduction of E-cad expression. Furthermore, TNF-α-induced Smurf2 expression promoted EMT through the Akt signaling pathway.

CONCLUSIONS

TNF-α induced EMT via the TNF-α/Akt/Smurf2 signaling pathways, and it may play a role in aggravating allograft kidney interstitial fibrosis in CAD patients.

Molecular correlates and prognostic value of tmTNF-α expression in colorectal cancer of 5-Fluorouracil-Based Adjuvant Therapy

Transmembrane tumor necrosis factor-α (tmTNF-α) is known to induce the activation of NF-κB to protect tumor cells. Upregulation of tmTNF-α leads to resistance to apoptosis and induces drug resistance in breast cancer. However, the expression of tmTNF-α in colorectal cancer (CRC) and its association with clinical outcome in CRC have remained unclear. In this study, we examined the tmTNF-α expression in CRC by immunohistochemistry and western blotting, assessed the prognostic value of tmTNF-α related to the recurrence/metastasis and survival of stage II/III CRC by the Kaplan-Meier survival curve and Cox regression model, and also explored the role of tmTNF-α expression on the chemotherapeutic efficacy of 5-Fluorouracil by flow cytometry assay and cell counting kit-8 (CCK-8) in vitro. Overall, we found that 77 (78.6%) out of 98 patients exhibited higher tmTNF-α expression in the CRC tissues comparing with the adjacent tissues. The tmTNF-α expression was correlated with Differentiation (P = 0.019), TNM stage (P = 0.039), Lymph nodes metastasis (P = 0.024) and Lymphovascular invasion (P = 0.027) but not related with Age (P = 0.617), Gender (P = 0.625), Tumor location (P = 0.138), Perforation/Obstruction (P = 1.000), Depth of invasion (P = 0.327), and microsatellite instability status (P = 0.150). The prognostic analyses showed that high tmTNF-α expression patients was significantly associated with decreased Disease-Free Survival (P = 0.0209) and Overall Survival (P = 0.0163). CCK-8 results suggested that the tmTNF-α influenced the chemotherapeutic effect of 5-Fluorouracil on colon cancer cells. Altogether, these data indicated the stageII/III CRC patients with high tmTNF-α expression were more likely to have a worse prognosis than patients with low tmTNF-α expression and tmTNF-α may influence the chemotherapeutic effect of 5-Fluorouracil. The mechanism for these observations warrants further study.

The deleterious interplay between tumor epithelia and stroma in cholangiocarcinoma

Prognosis of cholangiocarcinoma, a devastating liver epithelial malignancy characterized by early invasiveness, remains very dismal, though its incidence has been steadily increasing. Evidence is mounting that in cholangiocarcinoma, tumor epithelial cells establish an intricate web of mutual interactions with multiple stromal components, largely determining the pervasive behavior of the tumor. The main cellular components of the tumor microenvironment (i.e. myofibroblasts, macrophages, lymphatic endothelial cells), which has been recently termed as 'tumor reactive stroma', are recruited and activated by neoplastic cells, and in turn, deleteriously mold tumor behavior by releasing a huge variety of paracrine signals, including cyto/chemokines, growth factors, morphogens and proteinases. An abnormally remodeled and stiff extracellular matrix favors and supports these cell interactions. Although the mechanisms responsible for the generation of tumor reactive stroma are largely uncertain, hypoxia presumably plays a central role. In this review, we will dissect the intimate relationship among the different cell elements cooperating within this complex 'ecosystem', with the ultimate goal to pave the way for a deeper understanding of the mechanisms underlying cholangiocarcinoma aggressiveness, and possibly, to foster the development of innovative, combinatorial therapies aimed at halting tumor progression. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Understanding liver regeneration to bring new insights to the mechanisms driving cholangiocarcinoma

Cancer frequently arises in epithelial tissues subjected to repeated cycles of injury and repair. Improving our understanding of tissue regeneration is, therefore, likely to reveal novel processes with inherent potential for aberration that can lead to carcinoma. These highly conserved regenerative mechanisms are increasingly understood and in the liver are associated with special characteristics that underlie the organ's legendary capacity for restoration of size and function following even severe or chronic injury. The nature of the injury can determine the cellular source of epithelial regeneration and the signalling mechanisms brought to play. These observations are shaping how we understand and experimentally investigate primary liver cancer, in particular cholangiocarcinoma; a highly invasive malignancy of the bile ducts, resistant to chemotherapy and whose pathogenesis has hitherto been poorly understood. Interestingly, signals that drive liver development become activated in the formation of cholangiocarcinoma, such as Notch and Wnt and may be potential future therapeutic targets. In this review, we summarise the work which has led to the current understanding of the cellular source of cholangiocarcinoma, how the tumour recruits, sustains and is educated by its supporting stromal environment, and the tumour-derived signals that drive the progression and invasion of the cancer. With few current treatments of any true efficacy, advances that will improve our understanding of the mechanisms driving this aggressive malignancy are welcome and may help drive therapeutic developments.

Tumor reactive stroma in cholangiocarcinoma: The fuel behind cancer aggressiveness

Cholangiocarcinoma (CCA) is a highly aggressive epithelial malignancy still carrying a dismal prognosis, owing to early lymph node metastatic dissemination and striking resistance to conventional chemotherapy. Although mechanisms underpinning CCA progression are still a conundrum, it is now increasingly recognized that the desmoplastic microenvironment developing in conjunction with biliary carcinogenesis, recently renamed tumor reactive stroma (TRS), behaves as a paramount tumor-promoting driver. Indeed, once being recruited, activated and dangerously co-opted by neoplastic cells, the cellular components of the TRS (myofibroblasts, macrophages, endothelial cells and mesenchymal stem cells) continuously rekindle malignancy by secreting a huge variety of soluble factors (cyto/chemokines, growth factors, morphogens and proteinases). Furthermore, these factors are long-term stored within an abnormally remodeled extracellular matrix (ECM), which in turn can deleteriously mold cancer cell behavior. In this review, we will highlight evidence for the active role played by reactive stromal cells (as well as by the TRS-associated ECM) in CCA progression, including an overview of the most relevant TRS-derived signals possibly fueling CCA cell aggressiveness. Hopefully, a deeper knowledge of the paracrine communications reciprocally exchanged between cancer and stromal cells will steer the development of innovative, combinatorial therapies, which can finally hinder the progression of CCA, as well as of other cancer types with abundant TRS, such as pancreatic and breast carcinomas.

KLF7 overexpression in human oral squamous cell carcinoma promotes migration and epithelial-mesenchymal transition

Krüppel-like factor 7 (KLF7) is a member of the KLF family of zinc finger transcription factors, and was the first KLF cloned using complementary DNA and polymerase chain reaction (PCR) techniques with human vascular endothelial cells as a template. In addition, KLF7 is known as the ubiquitous Krüppel-like factor, as it is widely expressed in numerous human tissues at low levels. In the present study, the function of KLF7 in migration and epithelial-mesenchymal transition (EMT), which are associated with tumor progression, was investigated in human oral squamous cell carcinoma (OSCC) cells. Genes that were differentially expressed in normal vs. OSCC tissue were identified in the Gene Expression Omnibus database, which identified upregulation of KLF7 in OSCC. The expression and subcellular location of KLF7 was then analyzed using immunohistochemistry. KLF7 expression was measured in three OSCC cell lines, and the two cell lines with the highest (HN13) and lowest (CAL27) KLF7 expression were selected for further analysis. Subsequently, HN13 cells with reduced KLF7 expression (sh-HN13) and CAL27 cells overexpressing KLF7 (OE-CAL27) were constructed. Transwell migration and wound healing assays were then used to analyze the migration of the cells. In addition, mRNA and protein expression levels of the EMT markers E-cadherin, N-cadherin, vimentin and snail were detected using reverse transcription-quantitative PCR and western blotting. KLF7 overexpression in OSCC was validated using tissue immunohistochemistry, which identified moderate to high cytoplasmic staining of KLF7 in OSCC cells. KLF7 knockdown and overexpression altered the migration ability of sh-HN13 and OE-CAL27 cells, which decreased and increased significantly respectively. Expression of E-cadherin, N-cadherin, vimentin and snail was markedly altered in sh-HN13 and OE-CAL27 cells, indicating changes in EMT status. The results of the present study suggest that KLF7 overexpression changes the migratory behavior of OSCC cells, and induces EMT and lymph node metastasis through the expression of snail.

Epithelial-mesenchymal transition in cholangiocarcinoma: From clinical evidence to regulatory networks

Cholangiocarcinoma (CCA) is an aggressive tumor with a poor prognosis due to its late clinical presentation and the lack of effective non-surgical therapies. Unfortunately, most of the patients are not eligible for curative surgery owing to the presence of metastases at the time of diagnosis. Therefore, it is important to understand the steps leading to cell dissemination in patients with CCA. To metastasize from the primary site, cancer cells must acquire migratory and invasive properties by a cell plasticity-promoting phenomenon known as epithelial-mesenchymal transition (EMT). EMT is a reversible dynamic process by which epithelial cells gradually adopt structural and functional characteristics of mesenchymal cells, and has lately become a centre of attention in the field of metastatic dissemination. In the present review, we aim to provide an extensive overview of the current clinical data and the prognostic value of different EMT markers that have been analysed in CCA. We summarize all the regulatory networks implicated in EMT from the membrane receptors to the main EMT-inducing transcription factors (SNAIL, TWIST and ZEB). Furthermore, since a tumor is a complex structure not exclusively formed by tumor cells, we also address the prominent role of the main cell types of the desmoplastic stroma that characterizes CCA in the regulation of EMT. Finally, we discuss the therapeutic considerations and difficulties faced to develop an effective anti-EMT treatment due to the redundancies and bypasses among the pathways regulating EMT.

[Inflammation and Cancer Development in Pancreatic and Biliary Tract Cancer]

Chronic inflammation has been known to be a risk for many kinds of cancers, including pancreatic and biliary tract cancer. Recently, inflammatory process has emerged as a key mediator of cancer development and progression. Many efforts with experimental results have been given to identify the underlying mechanisms that contribute to inflammation-induced tumorigenesis. Diverse inflammatory pathways have been investigated and inhibitors for inflammation-related signaling pathways have been developed for cancer treatment. This review will summarize recent outcomes about this distinctive process in pancreatic and biliary tract cancer. Taking this evidence into consideration, modulation of inflammatory process will provide useful options for pancreatic and biliary tract cancer treatment.

The Role of Cancer-Associated Fibroblasts and Fibrosis in Liver Cancer

Liver cancer is the second leading cause of cancer mortality worldwide, causing more than 700,000 deaths annually. Because of the wide landscape of genomic alterations and limited therapeutic success of targeting tumor cells, a recent focus has been on better understanding and possibly targeting the microenvironment in which liver tumors develop. A unique feature of liver cancer is its close association with liver fibrosis. More than 80% of hepatocellular carcinomas (HCCs) develop in fibrotic or cirrhotic livers, suggesting an important role of liver fibrosis in the premalignant environment (PME) of the liver. Cholangiocarcinoma (CCA), in contrast, is characterized by a strong desmoplasia that typically occurs in response to the tumor, suggesting a key role of cancer-associated fibroblasts (CAFs) and fibrosis in its tumor microenvironment (TME). Here, we discuss the functional contributions of myofibroblasts, CAFs, and fibrosis to the development of HCC and CCA in the hepatic PME and TME, focusing on myofibroblast- and extracellular matrix-associated growth factors, fibrosis-associated immunosuppressive pathways, as well as mechanosensitive signaling cascades that are activated by increased tissue stiffness. Better understanding of the role of myofibroblasts in HCC and CCA development and progression may provide the basis to target these cells for tumor prevention or therapy.

Tumor necrosis factor-alpha up-regulates expression of Jagged-1 and induces epithelial-mesenchymal transition in rat cholangiocytes in vitro

AIM: To investigate the role of tumor necrosis factor-alpha (TNF-α) in the epithelial-mesenchymal transition (EMT) process in rat cholangiocytes in vitro.

METHODS: Primary rat cholangiocytes were treated with TNF-α (10 ng/mL) alone, TNF-α plus nuclear factor kappa B (NF-κB) inhibitor PDTC (50 µmol/L), or PDTC alone for 72 h. The expression of Jagged-1, mesenchymal markers [fibroblast-specific protein-1 (FSP-1), Vimentin and α-SMA] as well as epithelial marker CK19 was detected by Western blot. NF-κB binding activity was measured by EMSA. Migration ability and morphological changes of cholangiocytes were also examined.

RESULTS: In the TNF-α alone group, the protein levels of Jagged-1, FSP-1, Vimentin and α-SMA were up-regulated compared to control cells, whereas the expression of CK19 was down-regulated. The migration ability of cholangiocytes was increased and their shape changed from stone-like to fiber-like. For the TNF-α plus PTCD group and the PTCD alone group, no significant changes in EMT markers as well as migration ability were observed compared to control cells.

CONCLUSION: TNF-α is able to increase the expression of Jagged-1 and induce EMT in rat cholangiocytes in vitro possibly through activation of NF-κB signaling.

Epithelial-to-Mesenchymal Transition and Cancer Invasiveness: What Can We Learn from Cholangiocarcinoma?

In addition to its well-established role in embryo development, epithelial-to-mesenchymal transition (EMT) has been proposed as a general mechanism favoring tumor metastatization in several epithelial malignancies. Herein, we review the topic of EMT in cholangiocarcinoma (CCA), a primary liver cancer arising from the epithelial cells lining the bile ducts (cholangiocytes) and characterized by an abundant stromal reaction. CCA carries a dismal prognosis, owing to a pronounced invasiveness and scarce therapeutic opportunities. In CCA, several reports indicate that cancer cells acquire a number of EMT biomarkers and functions. These phenotypic changes are likely induced by both autocrine and paracrine signals released in the tumor microenvironment (cytokines, growth factors, morphogens) and intracellular stimuli (microRNAs, oncogenes, tumor suppressor genes) variably associated with specific disease mechanisms, including chronic inflammation and hypoxia. Nevertheless, evidence supporting a complete EMT of neoplastic cholangiocytes into stromal cells is lacking, and the gain of EMT-like changes by CCA cells rather reflects a shift towards an enhanced pro-invasive phenotype, likely induced by the tumor stroma. This concept may help to identify new biomarkers of early metastatic behavior along with potential therapeutic targets.

Overexpression of HOXA10 promotes gastric cancer cells proliferation and HOXA10(+)/CD44(+) is potential prognostic biomarker for gastric cancer

Gastric cancer (GC) is a malignant cancer with poor prognosis. This study aims to investigate the roles of homeobox A10 (HOXA10) in GC and the correlations between HOXA10/CD44 expression and GC prognosis. Based on qRT-PCR and Western Blot analyses in 50 pairs of fresh GC samples and adjacent normal samples, it is identified that HOXA10 was significantly up-regulated in GC tissues at mRNA and protein levels. Cell proliferation, migration, and invasion were enhanced in GC cells with overexpressed HOXA10, while inhibited in cells with silenced HOXA10. Through IPA software, HOXA10 was predicted to interact with CD44 via MSN, which was preliminarily confirmed by using Western Blot. Through immunohistochemistry and tissue microarray (N=264), it is found that HOXA10 expression was significantly correlated with tumor size (P=0.011) and CD44 expression (P<0.001), while CD44 expression was significantly correlated with tumor size (P<0.001), depth of tumor invasion (P<0.001), lymph node metastasis (P<0.001), distant metastasis (P=0.001), UICC stage (P<0.001), histological differentiation (P<0.001), and HOXA10 expression (P<0.001). Additionally, the over-all survival and disease-free survival of HOXA10(+)/CD44(+) patients were dramatically decreased in comparison with that of HOXA10(+)/CD44(-), HOXA10(-)/CD44(+), or HOXA10(-)/CD44(-) patients (P<0.001), suggesting that the combinatory expression of HOXA10 and CD44 was correlated with poor GC prognosis. In conclusion, HOXA10 and CD44 might play roles in GC tumorigenesis, metastasis, and invasion. HOXA10(+)/CD44(+) expression might serve as a prognostic biomarker for GC, which needs more studies to validate.

Tumor Microenvironment Versus Cancer Stem Cells in Cholangiocarcinoma: Synergistic Effects?

Cholangiocarcinoma (CCAs) may be defined as tumors that derived from the biliary tree with the differentiation in the biliary epithelial cells. This tumor is malignant, extremely aggressive with a poor prognosis. It can be treated surgically and its pathogenesis is poorly understood. The tumor microenvironment (TME) is a very important factor in the regulation of tumor angiogenesis, invasion, and metastasis. Besides cancer stem cells (CSCs) can modulate tumor growth, stroma formation, and migratory capability. The initial stage of tumorigenesis is characterized by genetic mutations and epigenetic alterations due to intrinsic factors which lead to the generation of oncogenes thus inducing tumorigenesis. CSCs may result from precancerous stem cells, cell de-differentiation, normal stem cells, or an epithelial-mesenchymal transition (EMT). CSCs have been found in the cancer niche, and EMT may occur early within the tumor microenvironment. Previous studies have demonstrated evidence of cholangiocarcinoma stem cells (CD133, CD24, EpCAM, CD44, and others) and the presence of these markers has been associated with malignant potential. The interaction between TME and cholangiocarcinoma stem cells via signaling mediators may create an environment that accommodates tumor growth, yielding resistance to cytotoxic insults (chemotherarapeutic). While progress has been made in the understanding of the mechanisms, the interactions in the tumorigenic process still remain a major challenge. Our review, addresses recent concepts of TME-CSCs interaction and will emphasize the importance of early detection with the use of novel diagnostic mechanisms such as CCA-CSC biomarkers and the importance of tumor stroma to define new treatments. J. Cell. Physiol. 231: 768-776, 2016. © 2015 Wiley Periodicals, Inc.

Revealing gene clusters associated with the development of cholangiocarcinoma, based on a time series analysis

Cholangiocarcinoma (CC) is a rapidly lethal malignancy and currently is considered to be incurable. Biomarkers related to the development of CC remain unclear. The present study aimed to identify differentially expressed genes (DEGs) between normal tissue and intrahepatic CC, as well as specific gene expression patterns that changed together with the development of CC. By using a two‑way analysis of variance test, the biomarkers that could distinguish between normal tissue and intrahepatic CC dissected from different days were identified. A k‑means cluster method was used to identify gene clusters associated with the development of CC according to their changing expression pattern. Functional enrichment analysis was used to infer the function of each of the gene sets. A time series analysis was constructed to reveal gene signatures that were associated with the development of CC based on gene expression profile changes. Genes related to CC were shown to be involved in 'mitochondrion' and 'focal adhesion'. Three interesting gene groups were identified by the k‑means cluster method. Gene clusters with a unique expression pattern are related with the development of CC. The data of this study will facilitate novel discoveries regarding the genetic study of CC by further work.

Impact of microenvironment and stem-like plasticity in cholangiocarcinoma: molecular networks and biological concepts

Clinical complexity, anatomic diversity and molecular heterogeneity of cholangiocarcinoma (CCA) represent a major challenge in the assessment of effective targeted therapies. Molecular and cellular mechanisms underlying the diversity of CCA growth patterns remain a key issue of clinical concern. Crucial questions comprise the nature of the CCA-origin, the initial target for cellular transformation as well as the relationship with the cancer stem cells (CSC) concept. Additionally, since CCA often develops in the context of an inflammatory milieu (cirrhosis and cholangitis), the stromal compartment or tumour microenvironment (TME) likely promotes initiation and progression of this malignancy, contributing to its heterogeneity. This review will emphasize the dynamic interplay between stem-like intrinsic and TME-extrinsic pathways, which may represent novel options for multi-targeted therapies in CCA.

Inflammatory cytokines promote the retrodifferentiation of tumor-derived hepatocyte-like cells to progenitor cells

Human hepatocellular carcinoma (HCC) heterogeneity promotes recurrence and resistance to therapies. Recent studies have reported that HCC may be derived not only from adult hepatocytes and hepatoblasts but also hepatic stem/progenitors. In this context, HepaRG cells may represent a suitable cellular model to study stem/progenitor cancer cells and the retrodifferentiation of tumor-derived hepatocyte-like cells. Indeed, they differentiate into hepatocyte- and biliary-like cells. Moreover, tumor-derived HepaRG hepatocyte-like cells (HepaRG-tdHep) differentiate into both hepatocyte- and biliary-like cells through a hepatic progenitor. In this study we report the mechanisms and molecular effectors involved in the retrodifferentiation of HepaRG-tdHep into bipotent progenitors. Gene expression profiling was used to identify genomic changes during the retrodifferentiation of HepaRG-tdHep into progenitors. We demonstrated that gene expression signatures related to a poor-prognosis HCC subclass, proliferative progenitors, or embryonic stem cells were significantly enriched in HepaRG progenitors derived from HepaRG-tdHep. HepaRG-tdHep retrodifferentiation is mediated by crosstalk between transforming growth factor beta 1 (TGFβ1) and inflammatory cytokine pathways (e.g., tumor necrosis factor alpha [TNFα] and interleukin 6 [IL6]). Signatures related to TNFα, IL6, and TGFβ activation pathways are induced within the first hour of retrodifferentiation. Moreover, specific activation or inhibition of these signaling pathways allowed us to determine that TNFα and IL6 contribute to the loss of hepatic-specific marker expression and that TGFβ1 induces an epithelial-to-mesenchymal transition of HepaRG-tdHep. Interestingly, the retrodifferentiation process is blocked by the histone deacetylase inhibitor trichostatin A, opening new therapeutic opportunities.

CONCLUSION

Cancer progenitor cells (or metastasis progenitors) may derive from tumor-derived hepatocyte-like cells in an inflammatory environment that is frequently associated with HCC.

Soluble a‑proliferation‑inducing ligand (sAPRIL), a novel serum biomarker predicting the recurrence and metastasis of pancreatic adenocarcinoma after surgery

Pancreatic adenocarcinoma (PA) is a leading cause of adult cancer mortality, and surgery is still the best available treatment strategy. However, PA can recur at any time and has limited prognosis. It is therefore necessary to explore novel serum biomarkers of PA to allow the early diagnosis of PA. Soluble a-proliferation-inducing ligand (sAPRIL), a promising inducer of the epithelial-mesenchymal transition (EMT), is often found overexpressed in a variety of autoimmune diseases. To determine whether serum sAPRIL can constitute a PA biomarker, the protein level of sAPRIL was examined by immunohistochemistry and western blot, and the mRNA level was quantified by RT-qPCR. The PA cell line PanC-1 was transfected with vectors bearing the sAPRIL gene and sAPRIL short hairpin RNA (shRNA) oligos. Increased expression of serum sAPRIL was observed in patients with PA recurrence or metastasis after five-year surgery compared to subjects without PA recurrence or metastasis. The growth rate of PanC-1 cells transfected with the sAPRIL expression vector was increased by 23% (P<0.01, vs. control group), and was reduced by 17% (P<0.01, vs. control group) in the sAPRIL shRNA-silenced cell line. Thus, sAPRIL is highly expressed in PA, and serum levels of sAPRIL can serve as a useful indicator for the recurrence or metastasis of PA after surgery. Additional validation studies on the use of serum sAPRIL as a diagnostic marker in PA are however needed.

BMP-7 blocks the effects of TGF-β-induced EMT in cholangiocarcinoma

Epithelial-mesenchymal transition (EMT) is characterized by the loss of epithelial markers and the gain of mesenchymal markers. EMT is believed to be a major mechanism supporting cancer cell metastasis. The activation of EMT can be induced by various types of inflammatory cytokines including transforming growth factor β (TGF-β) whereas bone morphogenetic protein-7 (BMP-7) can inhibit this process. In this study, the up-regulation of Twist transcription factor and N-cadherin, mesenchymal marker in CCA tissues, has been demonstrated and it has been found that the high expression of Twist was significantly associated with poor prognosis of CCA patients (P = 0.010). Moreover, CCA samples showing Twist nuclear expression were significantly correlated with the up-regulation of N-cadherin (P = 0.024). These results also showed that the inflammatory mediator TGF-β induces CCA cell migration, one of the metastatic processes possibly via stimulation of Twist, N-cadherin and vimentin expression. Additionally, it has been shown that BMP-7 inhibits TGF-β-induced CCA cell migration, through inhibition of TGF-β-mediated Twist and N-cadherin expressions. These data reinforce the rationale to use BMP-7 as an EMT inhibitor to suppress the progression of CCA and might be a therapeutic approach to improve efficiency for CCA treatment.

Activated macrophages down-regulate expression of E-cadherin in hepatocellular carcinoma cells via NF-κB/Slug pathway

Hepatocellular carcinomas are an aggressive malignancy mainly due to metastasis or postsurgical recurrence. Expression of E-cadherin is strongly reduced in Hepatocellular carcinoma (HCC) tissues, and its downregulation is connected to invasiveness and metastasis in hepatocellular carcinomas. The previous study showed that the supernatant from activated macrophages can downregulate the expression of E-cadherin in HCC cells. The partial known molecular mechanism is that tyrosine kinases c-Src- and EGFR phosphorylate β-catenin and E-cadherin leading to destabilization of E-cadherin/β-catenin complex. The aim of this study is to clarify other mechanism by which activated macrophages downregulate the expression of E-cadherin. We detect the expression of E-cadherin and macrophage infiltration in hepatocellular carcinoma tissues by double-staining immunohistochemistry and evaluate the relationship between macrophages and E-cadherin expression in hepatocellular carcinoma cells in vitro experiments. We found that reduced expression of E-cadherin was associated with macrophage infiltration along the border between the tumor nest and stroma in hepatocellular carcinoma tissues. Besides, protein expression of E-cadherin was significantly decreased in hepatocellular carcinoma cells co-cultured with macrophages derived from THP-1 cells. Consistently, mRNA expression of E-cadherin was also decreased in cancer cells co-cultured with THP-1-differentiated macrophages. Moreover, the downregulation of E-cadherin expression was companied by upregulation of Slug expression in cancer cells with conditional medium from THP-1-differentiated macrophage culture. The change in expression of E-cadherin and Slug was abrogated when NF-κB signaling pathway was blocked. All the findings suggested that macrophages contributed to the decreased expression of E-cadherin by NF-κB/Slug pathway in hepatocellular carcinomas.

Loss of E-cadherin promotes migration and invasion of cholangiocarcinoma cells and serves as a potential marker of metastasis

Tumor progression is characterized by loss of cell adhesion and increase of invasion and metastasis. E-cadherin, a cell adhesion molecule, is frequently downregulated and has been proposed as an important mediator in epithelial-mesenchymal transition (EMT) in tumors. In this study, we investigated the expression of E-cadherin and its association with cancer invasion and prognosis in cholangiocarcinoma (CCA). Immunohistochemistry results demonstrated a statistically significant association between the positive metastasis status with low E-cadherin protein expression in human CCA tissues (P = 0.04). Statistical trends were identified for low E-cadherin level and shorter survival time (P = 0.08). Targeting the E-cadherin expression in CCA cells with siRNA caused upregulation of vimentin, a mesenchymal marker, and disappearance of the E-cadherin/β-catenin adhesion complex from cell membranes. Moreover, migration and invasion abilities of the cells were increased under this condition. These findings suggest that reduction of E-cadherin contributes to CCA progression by attenuating the strength of cellular adhesion, which affects motility as well as regulating the expression of EMT-related genes during CCA invasion and metastasis. Thus, E-cadherin can act as a central modulator of tumor cell phenotype and is a potential metastasis marker in CCA.

Tumor necrosis factor-α modulates epithelial mesenchymal transition mediators ZEB2 and S100A4 to promote cholangiocarcinoma progression

BACKGROUND

The epithelial-mesenchymal transition (EMT) process strongly contributes to cancer metastasis. This study was to investigate the alteration of EMT-related proteins (ZEB1, ZEB2 and S100A4) in cholangiocarcinoma (CCA) tissues. The effect of tumor necrosis factor-α (TNF-α) on the expression of those molecules in CCA cells was investigated.

METHODS

The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used to quantify ZEB1, ZEB2 and S100A4 mRNA levels in 50 CCA tissues and related its expression to clinicopathological data. ZEB2 protein immunostaining was investigated in 165 CCA tissues. The effect of TNF-α on EMT-related CCA cell migration was evaluated using qRT-PCR, immunofluorescence and transwell migration assays.

RESULTS

ZEB2 and S100A4 mRNA levels were found to be higher in CCA tissues. High levels of S100A4 mRNA and ZEB2 protein were significantly associated with CCA metastasis (P = 0.04 and P = 0.03). Moreover, a trend toward statistical association was found with high levels of both ZEB2 mRNA and protein with shorter survival time (P = 0.10 and P = 0.19). In addition, TNF-α induced CCA cell migration by the induction of transforming growth factor-β (TGF-β) resulting in ZEB2 and S100A4 mRNA and protein activation.

CONCLUSIONS

These studies demonstrate that TNF-α plays crucial role in the progression of CCA by activating TGF-β signaling and the induction of ZEB2 and S100A4, EMT-related proteins expression.