Interleukin-6-driven progranulin expression increases cholangiocarcinoma growth by an Akt-dependent mechanism

Dysregulation of bile acid signal transduction causes neurological dysfunction in cirrhosis rats

BACKGROUND

The pathogenesis of hepatic encephalopathy (HE) remains unclear, and the classical theory of ammonia toxicity lacks sufficient justification.

AIM

To investigate the potential of bile acids as intervention targets for HE.

METHODS

This study employed 42 wild-type male SD rats weighing 200 ± 20 g. Using a random number table method, two rats were randomly selected to undergo common bile duct ligation (BDL). The remaining 40 rats were randomly assigned to four groups serving as controls: The vehicle + control diet (VC) group, the thioacetamide (TAA) group, the TAA + total bile acids (TAAT) group, and the TAA + cholestyramine (TAAC) group. Except for the VC group, all rats were intraperitoneally injected with 100 mg/kg TAA solution once daily for ten consecutive days to establish a HE model. Simultaneously, the TAAT and TAAC groups were administered a diet containing 0.3% bile acids (derived from BDL rats) and 2% cholestyramine, respectively, by gavage for ten days. For the BDL rat model group, the common BDL procedure was performed following the aforementioned protocol. After four weeks, laparotomy revealed swollen bile ducts at the ligation site, and bile was collected. Following successful modeling, behavioral tests, including the elevated plus maze and open field test, were conducted to assess the HE status of the rats. Peripheral blood, liver, and cerebral cortex tissue samples were collected, and the total bile acid content in the serum and cerebral cortex was measured using an enzyme cycling method. The levels of inflammatory factors in the serum and cerebral cortex were analyzed using enzyme-linked immunosorbent assay. Liver histological examination was performed using the hematoxylin-eosin double-labeling method. Reverse transcription polymerase chain reaction, western blot, immunohistochemistry, and other techniques were employed to observe the expression of microglial activation marker ionized calcium-binding adaptor molecule-1 and Takeda G protein-coupled receptor 5 (TGR5) protein.

RESULTS

Compared to the VC group, the TAA group exhibited an exacerbation of HE in rats. The total bile acid content, pro-inflammatory factors [interleukin-1β (IL-1β), IL-6], and the anti-inflammatory factor IL-10 in both the serum and cerebral cortex were significantly elevated. Similarly, the expression of the TGR5 receptor in the cerebral cortex was upregulated. To investigate the impact of total bile acids on HE in rats, comparisons were made with the TAA group. In the TAAT group, the severity of HE was further aggravated, accompanied by increased total bile acid content in the serum and cerebral cortex, elevated pro-inflammatory factors (IL-1β, IL-6), reduced levels of the anti-inflammatory factor IL-10, and decreased expression of the TGR5 receptor in the cerebral cortex. In the TAAC group, the severity of HE was alleviated. This group showed reductions in total bile acid content in the serum and cerebral cortex, decreased pro-inflammatory factors (IL-1β, IL-6), increased levels of the anti-inflammatory factor IL-10, and enhanced expression of the TGR5 receptor in the cerebral cortex.

CONCLUSION

This study demonstrated that the total bile acid content in the serum and cerebral cortex of TAA-induced liver cirrhosis rats was elevated. Furthermore, total bile acids exacerbate the progression of HE in rats. This effect may be attributed to bile acids' involvement in the development of neurological dysfunction by mediating TGR5 expression and regulating neuroinflammation.

CD47 signaling induces hepatic cell death and microglia activation during hepatic encephalopathy

Acute liver failure results from severe hepatic injury and can lead to neurological dysfunction known as hepatic encephalopathy (HE). Thrombospondin-1 can contribute to HE by increasing cerebral edema and microglia activation in the azoxymethane (AOM) mouse model. CD47 is a receptor for TSP1 and can directly modulate inflammation in numerous disease states. However, the role of CD47 in the progression of HE is currently unknown. Therefore, the aim of this study was to assess the role of CD47 in liver and brain pathology in the AOM mouse model of HE. C57Bl/6 or CD47 knockout (CD47-/-) were administered AOM to induce acute liver failure and HE. Liver damage was evaluated by measuring serum transaminases and histological assessment. Neurological function was determined by evaluating the time taken to reach coma (loss of all reflexes), cerebral edema, and microglia activation. CD47 signaling, and downstream signaling pathways, were assessed by real-time PCR, western blotting, immunofluorescence, and immunohistochemistry. AOM-treated mice had increased expression of CD47 in the liver, cortex, hippocampus, and cerebellum when compared to vehicle-treated mice. CD47-/- AOM-treated mice had reduced liver injury and apoptosis when compared to wildtype AOM-treated mice. A slower degree of neurological decline and less cerebral edema were observed in CD47-/- mice compared to wildtype AOM-treated mice. This was associated with decreased microglia proliferation and increased SOD1 expression in CD47-/- mice compared to wildtype AOM-treated mice. These findings support that CD47 signaling exacerbates AOM-induced acute liver failure and HE by inducing hepatic cell death, cerebral edema, and microglia activation.

Bioinformatics- and quantitative proteomics-based identification of gastric adenocarcinoma-related proteins and analysis

BACKGROUND

The emergence of immune resistance and a lack of effective therapeutic targets have become significant challenges in immunotherapy, highlighting the urgent need for new molecular markers and treatment targets. Moreover, the significance and mechanisms of PGRN (Progranulin) in gastric cancer remain ambiguous.

OBJECTIVE

To identify differentially expressed proteins in gastric cancer and elucidate the function and mechanism of PGRN.

METHODS

The data-independent acquisition proteomics was used to identify the differentially expressed proteins in gastric adenocarcinoma and the corresponding paraneoplastic tissues, providing a comprehensive dataset of gastric cancer-related proteins. The function and mechanism of PGRN in gastric cancer were further explored using a series of experiments, including RT-qPCR (Real Time-Quantitative Polymerase Chain Reaction), cell transfection, cell viability assays, cell scratch, immunohistochemistry and Transwell assays, Western blot, and a mouse tumor-bearing model. These investigations were combined with bioinformatics analyses to examine the relationship between PGRN expression and clinical-pathological characteristics, confirming its high expression of PGRN in gastric cancer tissues.

RESULTS

We identified a large number of differentially expressed proteins between gastric cancer and adjacent tissues and conducted an initial functional analysis. Further studies on PGRN showed that it was associated with gastric cancer prognosis and lymph node metastasis. The inhibition of PGRN expression led to reduced cell viability, migration, and invasion, with corresponding changes in related genes and proteins. In a mouse tumor-bearing model, the tumor growth of the subcutaneously transplanted tumors in nude mice was reduced after the inhibition of PGRN expression. An in-depth functional analysis of PGRN was performed using bioinformatics to predict protein interactions, miRNA regulation, and relationships with multiple immune cell types. Enrichment analysis indicated that PGRN is involved in multiple signaling pathways, with the MAPK (Mitogen-Activated Protein Kinase) pathway selected for validation. In AGS and HGC27 cells, PGRN inhibition led to increased expression of phosphorylated p38 (p-p38) in the MAPK pathway, suggesting that PGRN may promote gastric cancer development by regulating p-p38.

CONCLUSIONS

This study identified significant differences in protein expression between gastric adenocarcinoma and adjacent tissues, with PGRN emerging as a key protein influencing gastric cancer proliferation, migration, and invasion. These findings suggest that PGRN could serve as a potential therapeutic target for gastric cancer.

Progranulinopathy: A diverse realm of disorders linked to progranulin imbalances

Progranulin (PGRN), encoded by the GRN gene in humans, was originally isolated as a secreted growth factor that implicates in a multitude of processes ranging from regulation of tumorigenesis, inflammation to neural proliferation. Compelling evidence indicating that GRN mutation can lead to various common neuronal degenerative diseases and rare lysosomal storage diseases. These findings have unveiled a critical role for PGRN as a lysosomal protein in maintaining lysosomal function. The phenotypic spectrum of PGRN imbalance has expanded to encompass a broad spectrum of diseases, including autoimmune diseases, metabolic, musculoskeletal and cardiovascular diseases. These diseases collectively referred to as Progranulinopathy- a term encompasses the wide spectrum of disorders influenced by PGRN imbalance. Unlike its known extracellular function as a growth factor-like molecule associated with multiple membrane receptors, PGRN also serves as an intracellular co-chaperone engaged in the folding and traffic of its associated proteins, particularly the lysosomal hydrolases. This chaperone activity is required for PGRN to exert its diverse functions across a broad range of diseases, encompassing both the central nervous system and peripheral systems. In this comprehensive review, we present an update of the emerging role of PGRN in Progranulinopathy, with special focus on elucidating the intricate interplay between PGRN and a diverse array of proteins at various levels, ranging from extracellular fluids and intracellular components, as well as various pathophysiological processes involved. This review seeks to offer a comprehensive grasp of PGRN's diverse functions, aiming to unveil intricate mechanisms behind Progranulinopathy and open doors for future research endeavors.

Interleukin-6 Induces Stem Cell Propagation through Liaison with the Sortilin-Progranulin Axis in Breast Cancer

Unraveling the complex network between cancer cells and their tumor microenvironment is of clinical importance, as it might allow for the identification of new targets for cancer treatment. Cytokines and growth factors secreted by various cell types present in the tumor microenvironment have the potential to affect the challenging subpopulation of cancer stem cells showing treatment-resistant properties as well as aggressive features. By using various model systems, we investigated how the breast cancer stem cell-initiating growth factor progranulin influenced the secretion of cancer-associated proteins. In monolayer cultures, progranulin induced secretion of several inflammatory-related cytokines, such as interleukin (IL)-6 and -8, in a sortilin-dependent manner. Further, IL-6 increased the cancer stem fraction similarly to progranulin in the breast cancer cell lines MCF7 and MDA-MB-231 monitored by the surrogate mammosphere-forming assay. In a cohort of 63 patient-derived scaffold cultures cultured with breast cancer cells, we observed significant correlations between IL-6 and progranulin secretion, clearly validating the association between IL-6 and progranulin also in human-based microenvironments. In conclusion, the interplay between progranulin and IL-6 highlights a dual breast cancer stem cell-promoting function via sortilin, further supporting sortilin as a highly relevant therapeutic target for aggressive breast cancer.

Primary Sclerosing Cholangitis-Associated Cholangiocarcinoma: From Pathogenesis to Diagnostic and Surveillance Strategies

Cholangiocarcinoma (CCA) is the most common malignancy in patients with primary sclerosing cholangitis (PSC), accounting for 2-8% of cases and being the leading cause of death in these patients. The majority of PSC-associated CCAs (PSC-CCA) develop within the first few years after PSC diagnosis. Older age and male sex, as well as concomitant inflammatory bowel disease (IBD) or high-grade biliary stenosis, are some of the most relevant risk factors. A complex combination of molecular mechanisms involving inflammatory pathways, direct cytopathic damage, and epigenetic and genetic alterations are involved in cholangiocytes carcinogenesis. The insidious clinical presentation makes early detection difficult, and the integration of biochemical, radiological, and histological features does not always lead to a definitive diagnosis of PSC-CCA. Surveillance is mandatory, but current guideline strategies failed to improve early detection and consequently a higher patient survival rate. MicroRNAs (miRNAs), gene methylation, proteomic and metabolomic profile, and extracellular vesicle components are some of the novel biomarkers recently applied in PSC-CCA detection with promising results. The integration of these new molecular approaches in PSC diagnosis and monitoring could contribute to new diagnostic and surveillance strategies.

Circ_0020256 induces fibroblast activation to drive cholangiocarcinoma development via recruitment of EIF4A3 protein to stabilize KLF4 mRNA

Cancer-associated fibroblasts (CAFs) are a kind of stromal cells in the cholangiocarcinoma (CCA) microenvironment, playing crucial roles in cancer development. However, the potential mechanisms of the interaction between CCA cells and CAFs remain obscure. This work investigated the role of circ_0020256 in CAFs activation. We proved circ_0020256 was up-regulated in CCA. High circ_0020256 expression facilitated TGF-β1 secretion from CCA cells, which activated CAFs via the phosphorylation of Smad2/3. Mechanistically, circ_0020256 recruited EIF4A3 protein to stabilize KLF4 mRNA and upregulate its expression, then KLF4 bound to TGF-β1 promoter and induced its transcription in CCA cells. KLF4 overexpression abrogated the inhibition of circ_0020256 silencing in TGF-β1/Smad2/3-induced CAFs activation. Furthermore, CCA cell growth, migration, and epithelial-mesenchymal transition were favored by CAFs-secreted IL-6 via autophagy inhibition. We also found circ_0020256 accelerated CCA tumor growth in vivo. In conclusion, circ_0020256 promoted fibroblast activation to facilitate CCA progression via EIF4A3/KLF4 pathway, providing a potential intervention for CCA progression.

Progranulin Oncogenic Network in Solid Tumors

Progranulin is a pleiotropic growth factor with important physiological roles in embryogenesis and maintenance of adult tissue homeostasis. While-progranulin deficiency is associated with a broad range of pathological conditions affecting the brain, such as frontotemporal dementia and neuronal ceroid lipofuscinosis, progranulin upregulation characterizes many tumors, including brain tumors, multiple myeloma, leiomyosarcoma, mesothelioma and epithelial cancers such as ovarian, liver, breast, bladder, adrenal, prostate and kidney carcinomas. The increase of progranulin levels in tumors might have diagnostic and prognostic significance. In cancer, progranulin has a pro-tumorigenic role by promoting cancer cell proliferation, migration, invasiveness, anchorage-independent growth and resistance to chemotherapy. In addition, progranulin regulates the tumor microenvironment, affects the function of cancer-associated fibroblasts, and modulates tumor immune surveillance. However, the molecular mechanisms of progranulin oncogenic function are not fully elucidated. In bladder cancer, progranulin action relies on the activation of its functional signaling receptor EphA2. Notably, more recent data suggest that progranulin can also modulate a functional crosstalk between multiple receptor-tyrosine kinases, demonstrating a more complex and context-dependent role of progranulin in cancer. Here, we will review what is currently known about the function of progranulin in tumors, with a focus on its molecular mechanisms of action and regulation.

Interleukin-6-derived cancer-associated fibroblasts activate STAT3 pathway contributing to gemcitabine resistance in cholangiocarcinoma

Cancer-associated fibroblasts (CAFs) are the dominant component of the tumor microenvironment (TME) that can be beneficial to the generation and progression of cancer cells leading to chemotherapeutic failure via several mechanisms. Nevertheless, the roles of CAFs on anti-cancer drug response need more empirical evidence in cholangiocarcinoma (CCA). Herein, we examined the oncogenic roles of CAFs on gemcitabine resistance in CCA cells mediated via IL-6/STAT3 activation. Our findings showed that CCA-derived CAFs promote cell viability and enhance gemcitabine resistance in CCA cells through the activation of IL-6/STAT3 signaling. High expression of IL-6R was correlated with a poor overall survival rate and gemcitabine resistance in CCA, indicating that IL-6R can be a prognostic or predictive biomarker for the chemotherapeutic response of CCA patients. Blockade of IL-6R on CCA cells by tocilizumab, an IL-6R humanized antihuman monoclonal antibody, contributed to inhibition of the CAF-CCA interaction leading to enhancement of gemcitabine sensitivity in CCA cells. The results of this study should be helpful for modifying therapeutic regimens aimed at targeting CAF interacting with cancer cells resulting in the suppression of the tumor progression but enhancement of drug sensitivity.

Progranulin A Promotes Compensatory Hepatocyte Proliferation via HGF/c-Met Signaling after Partial Hepatectomy in Zebrafish

Compensatory hepatocyte proliferation and other liver regenerative processes are activated to sustain normal physiological function after liver injury. A major mitogen for liver regeneration is hepatocyte growth factor (HGF), and a previous study indicated that progranulin could modulate c-met, the receptor for HGF, to initiate hepatic outgrowth from hepatoblasts during embryonic development. However, a role for progranulin in compensatory hepatocyte proliferation has not been shown previously. Therefore, this study was undertaken to clarify whether progranulin plays a regulatory role during liver regeneration. To this end, we established a partial hepatectomy regeneration model in adult zebrafish that express a liver-specific fluorescent reporter. Using this model, we found that loss of progranulin A (GrnA) function by intraperitoneal-injection of a Vivo-Morpholino impaired and delayed liver regeneration after partial hepatectomy. Furthermore, transcriptome analysis and confirmatory quantitative real-time PCR suggested that cell cycle progression and cell proliferation was not as active in the morphants as controls, which may have been the result of comparative downregulation of the HGF/c-met axis by 36 h after partial hepatectomy. Finally, liver-specific overexpression of GrnA in transgenic zebrafish caused more abundant cell proliferation after partial hepatectomy compared to wild types. Thus, we conclude that GrnA positively regulates HGF/c-met signaling to promote hepatocyte proliferation during liver regeneration.

Update on the association of hepatitis B with intrahepatic cholangiocarcinoma: Is there new evidence?

Intrahepatic cholangiocarcinoma (iCCA) is a subgroup of cholangiocarcinoma that accounts for about 10%-20% of the total cases. Infection with hepatitis B virus (HBV) is one of the most important predisposing factors leading to the formation of iCCA. It has been recently estimated based on abundant epidemiological data that the association between HBV infection and iCCA is strong with an odds ratio of about 4.5. The HBV-associated mechanisms that lead to iCCA are under intense investigation. The diagnosis of iCCA in the context of chronic liver disease is challenging and often requires histological confirmation to distinguish from hepatocellular carcinoma. It is currently unclear whether antiviral treatment for HBV can decrease the incidence of iCCA. In terms of management, surgical resection remains the mainstay of treatment. There is a need for effective treatment modalities beyond resection in both first- and second-line treatment. In this review, we summarize the epidemiological evidence that links the two entities, discuss the pathogenesis of HBV-associated iCCA, and present the available data on the diagnosis and management of this cancer.

Progranulin in neurodegenerative dementia

Long-term or severe lack of protective factors is important in the pathogenesis of neurodegenerative dementia. Progranulin (PGRN), a neurotrophic factor expressed mainly in neurons and microglia, has various neuroprotective effects such as anti-inflammatory effects, promoting neuron survival and neurite growth, and participating in normal lysosomal function. Mutations in the PGRN gene (GRN) have been found in several neurodegenerative dementias, including frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD). Herein, PGRN deficiency and PGRN hydrolytic products (GRNs) in the pathological changes related to dementia, including aggregation of tau and TAR DNA-binding protein 43 (TDP-43), amyloid-β (Aβ) overproduction, neuroinflammation, lysosomal dysfunction, neuronal death, and synaptic deficit have been summarized. Furthermore, as some therapeutic strategies targeting PGRN have been developed in various models, we highlighted PGRN as a potential anti-neurodegeneration target in dementia.

Cancer-Associated Fibroblast-Derived IL-6 Determines Unfavorable Prognosis in Cholangiocarcinoma by Affecting Autophagy-Associated Chemoresponse

Simple Summary

We aimed to validate with clinical and molecular data the hypothesis that CAF infiltration and release of IL-6 predict poor prognosis in CCA patients following dysregulation of autophagy in cancer cells. Stromal IL-6 and cancer-cell-associated autophagy proteins were assayed by Tissue MicroArray immunohistochemistry and their expression correlated with overall survival (OS) in a cohort of 70 CCA patients. We found that patients bearing a CCA with low stromal IL-6 and active autophagy flux in the cancer cells have the best prognosis and this correlates with a more effective response to post-operative chemotherapy. A similar trend was observed in CCA patients from the TCGA database. In vitro experiments with primary CAFs isolated from human CCA showed that IL-6 impairs the autophagy-associated apoptotic response to 5-FU in human CCA cells. Stromal IL-6 inhibition of autophagy in cancer cells was confirmed in an animal model of CCA. Our data support a therapeutic strategy that includes drugs limiting the stromal inflammation and enhancing autophagy to improve the survival of CCA patients.

Abstract

Background: Interleukin-6 (IL-6) released by cancer-associated fibroblasts (CAFs) has been shown to associate with the malignant behavior of cholangiocarcinoma (CCA). Here, we aimed to validate with clinical and molecular data the hypothesis that CAF infiltration and release of IL-6 predict poor prognosis in CCA patients following dysregulation of autophagy in cancer cells. Methods: Stromal IL-6 and cancer-cell-associated autophagy proteins LC3 and p62 were assayed by Tissue MicroArray immunohistochemistry and their expression correlated with overall survival (OS) in a cohort of 70 CCA patients. The 5-FU cytotoxicity and autophagy were determined in CCA cells cultured with CAF-conditioned medium. Results: We show that patients bearing a CCA with low production of stromal IL-6 and active autophagy flux in the cancer cells have the best prognosis and this correlates with a more effective response to post-operative chemotherapy. A similar trend was observed in CCA patients from the TCGA database. In vitro genetic manipulation of IL-6 production by primary CAFs isolated from human CCA showed that IL-6 impairs the autophagy-associated apoptotic response to 5-FU in human CCA cells. Stromal IL-6 inhibition of autophagy in cancer cells was confirmed in an animal model of CCA. Conclusion: Our data support a therapeutic strategy that includes autophagy-enhancing drugs along with adjuvants limiting the stromal inflammation (i.e., the secretion of IL-6) to improve the survival of CCA patients.

Targeting the tumor microenvironment in cholangiocarcinoma: implications for therapy

Introduction: Cholangiocarcinomas (CCAs) are biliary epithelial tumors with rising incidence over the past 3 decades. Early diagnosis of CCAs remains a significant challenge and the majority of patients present at an advanced stage. CCAs are heterogeneous tumors and currently available standard systemic therapy options are of limited effectiveness. Immune checkpoint inhibition (ICI) has transformed cancer therapy across a spectrum of malignancies. However, the response rate to ICI has been relatively disappointing in CCAs owing to its desmoplastic tumor microenvironment (TME).Areas covered: Tumor microenvironment of CCAs consists of innate and adaptive cells, stromal cells, and extracellular components (cytokines, chemokines, exosomes, etc.). This intricate microenvironment has multiple immunosuppressive elements that promote tumor cell survival and therapeutic resistance. Accordingly, there is a need for the development of effective therapeutic strategies that target the TME. Herein, we review the components of the CCA TME, and potential therapies targeting the CCA TME.Expert opinion: CCAs are desmoplastic tumors with a dense tumor microenvironment. An enhanced understanding of the various components of the CCA TME is essential in the effort to develop novel biomarkers for patient stratification as well as combination therapeutic strategies that target the tumor plus the TME.

The converging roles of Batten disease proteins in neurodegeneration and cancer

Epidemiological studies have reported an inverse correlation between cancer and neurodegenerative disorders, and increasing evidence shows that similar genes and pathways are dysregulated in both diseases but in a contrasting manner. Given the genetic convergence of the neuronal ceroid lipofuscinoses (NCLs), a family of rare neurodegenerative disorders commonly known as Batten disease, and other neurodegenerative diseases, we sought to explore the relationship between cancer and the NCLs. In this review, we survey data from The Cancer Genome Atlas and available literature on the roles of NCL genes in different oncogenic processes to reveal links between all the NCL genes and cancer-related processes. We also discuss the potential contributions of NCL genes to cancer immunology. Based on our findings, we propose that further research on the relationship between cancer and the NCLs may help shed light on the roles of NCL genes in both diseases and possibly guide therapy development.

The role and mechanisms of Microglia in Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neurological disease that can cause blindness and disability. As the major mediators in the central nervous system, microglia plays key roles in immunological regulation in neuroinflammatory diseases, including NMOSD. Microglia can be activated by interleukin (IL)-6 and type I interferons (IFN-Is) during NMOSD, leading to signal transducer and activator of transcription (STAT) activation. Moreover, complement C3a secreted from activated astrocytes may induce the secretion of complement C1q, inflammatory cytokines and progranulin (PGRN) by microglia, facilitating injury to microglia, neurons, astrocytes and oligodendrocytes in an autocrine or paracrine manner. These processes involving activated microglia ultimately promote the pathological course of NMOSD. In this review, recent research progress on the roles of microglia in NMOSD pathogenesis is summarized, and the mechanisms of microglial activation and microglial-mediated inflammation, and the potential research prospects associated with microglial activation are also discussed.

Progranulin/GP88, A Complex and Multifaceted Player of Tumor Growth by Direct Action and via the Tumor Microenvironment

Investigation of the role of progranulin/GP88 on the proliferation and survival of a wide variety of cells has been steadily increasing. Several human diseases stem from progranulin dysregulation either through its overexpression in cancer or its absence as in the case of null mutations in some form of frontotemporal dementia. The present review focuses on the role of progranulin/GP88 in cancer development, progression, and drug resistance. Various aspects of progranulin identification, biology, and signaling pathways will be described. Information will be provided about its direct role as an autocrine growth and survival factor and its paracrine effect as a systemic factor as well as via interaction with extracellular matrix proteins and with components of the tumor microenvironment to influence drug resistance, migration, angiogenesis, inflammation, and immune modulation. This chapter will also describe studies examining progranulin/GP88 tumor tissue expression as well as circulating level as a prognostic factor for several cancers. Due to the wealth of publications in progranulin, this review does not attempt to be exhaustive but rather provide a thread to lead the readers toward more in-depth exploration of this fascinating and unique protein.

Inhibition of thrombospondin-1 reduces glutathione activity and worsens acute liver injury during acetaminophen hepatotoxicity in mice

Acetaminophen (N-Acetyl-p-Aminophenol or APAP)-induced hepatotoxicity is the most common cause of acute liver failure in the United States and Western Europe. Previous studies have shown that TGFβ1 is elevated during APAP-induced hepatotoxicity and promotes liver injury by reducing liver regeneration while inducing hepatocyte senescence. At this time, little is known about the role of proteins that activate latent TGFβ1 and their effects during APAP-induced hepatotoxicity. Thrombospondin-1 (TSP1) is a homotrimeric protein that can not only activate latent TGFβ1 but can also interact with other proteins including Nrf2 to induce antioxidant signaling. The aim of the current study was to assess the role of thrombospondin-1 (TSP1) in both TGFβ1 activation and its contribution to APAP-induced liver injury. C57Bl/6 mice or TSP1 null mice (TSP1-/-) were administered 300 mg/kg or 600 mg/kg of APAP. TGFβ1 signaling, TSP1 expression, measures of hepatic injury, Nrf2 expression, measures of oxidative/nitrosative stress and GSH metabolism were assessed. The expression of TGFβ1, TSP1 and phosphorylation of SMAD proteins increased in APAP-treated mice compared to controls. TSP1-/- mice had reduced TGFβ1 expression and phosphorylation of SMAD proteins but increased liver injury. Hepatocyte cell death was increased in TSP1-/- mice and this was associated with decreased Nrf2 activity, decreased GSH levels and increased oxidative stress in comparison to wild-type C57Bl/6 mice. Together, these data demonstrate that elimination of TSP1 protein in APAP-treated mice reduces TGFβ1 signaling but leads to increased liver injury by reducing Nrf2 expression and GSH activity, ultimately resulting in increased cell death.

Pathogenesis of Cholangiocarcinoma

Cholangiocarcinoma (CCA) encompasses a group of malignancies that can arise at any point in the biliary tree. Although considered a rare cancer, the incidence of CCA is increasing globally. The silent and asymptomatic nature of these tumors, particularly in their early stages, in combination with their high aggressiveness, intra- and intertumor heterogeneity, and chemoresistance, significantly compromises the efficacy of current therapeutic options, contributing to a dismal prognosis. During the last few years, increasing efforts have been made to unveil the etiologies and pathogenesis of these tumors and to develop more effective therapies. In this review, we summarize current findings in the field of CCA, mainly focusing on the mechanisms of pathogenesis, cells of origin, genomic and epigenetic abnormalities, molecular alterations, chemoresistance, and therapies.

Ghrelin reverses ductular reaction and hepatic fibrosis in a rodent model of cholestasis

The orexigenic peptide ghrelin (Ghr) stimulates hunger signals in the hypothalamus via growth hormone secretagogue receptor (GHS-R1a). Gastric Ghr is synthetized as a preprohormone which is proteolytically cleaved, and acylated by a membrane-bound acyl transferase (MBOAT). Circulating Ghr is reduced in cholestatic injuries, however Ghr's role in cholestasis is poorly understood. We investigated Ghr's effects on biliary hyperplasia and hepatic fibrosis in Mdr2-knockout (Mdr2KO) mice, a recognized model of cholestasis. Serum, stomach and liver were collected from Mdr2KO and FVBN control mice treated with Ghr, des-octanoyl-ghrelin (DG) or vehicle. Mdr2KO mice had lower expression of Ghr and MBOAT in the stomach, and lower levels of circulating Ghr compared to WT-controls. Treatment of Mdr2KO mice with Ghr improved plasma transaminases, reduced biliary and fibrosis markers. In the liver, GHS-R1a mRNA was expressed predominantly in cholangiocytes. Ghr but not DG, decreased cell proliferation via AMPK activation in cholangiocytes in vitro. AMPK inhibitors prevented Ghr-induced FOXO1 nuclear translocation and negative regulation of cell proliferation. Ghr treatment reduced ductular reaction and hepatic fibrosis in Mdr2KO mice, regulating cholangiocyte proliferation via GHS-R1a, a G-protein coupled receptor which causes increased intracellular Ca2+ and activation of AMPK and FOXO1, maintaining a low rate of cholangiocyte proliferation.

Macrophage-derived progranulin promotes allergen-induced airway inflammation

BACKGROUND

Progranulin (PGRN), mainly produced by immune and epithelial cells, has been known to be involved in the development of various inflammatory diseases. However, the function of PGRN in allergic airway inflammation has not been clearly elucidated, and we investigated the role of PGRN in allergic airway inflammation.

METHODS

Production of PGRN and various type 2 cytokines was evaluated in mouse airways exposed to house dust mite allergen, and main cellular sources of these molecules were investigated using macrophage, airway epithelial cell, and NKT cell lines. We elucidated the role of PGRN in allergic airway inflammation in mouse models of asthma using macrophage-derived PGRN-deficient mice and NKT cell knockout mice by evaluating cytokine levels in bronchoalveolar lavage fluids and histopathology. We also supplemented recombinant PGRN in the mouse models to confirm the role of PGRN in allergic airway inflammation.

RESULTS

PGRN production preceded other cytokines, mainly from macrophages, in the airway exposed to allergen. PGRN induced IL-4 and IL-13 production in NKT cells and IL-33 and TSLP in airway epithelial cells. PGRN-induced Th2 cytokine production was abolished in NKT-deficient mice. Finally, allergic inflammation was significantly attenuated in allergen-exposed PGRN-deficient mice, but inflammation was restored when recombinant PGRN was supplemented during the allergen sensitization period.

CONCLUSION

The presence of macrophage-derived PGRN in airways in the early sensitization period may be critical for mounting a Th2 immune response and for following an allergic airway inflammation pathway via induction of type 2 cytokine production in NKT and airway epithelial cells.

FOXO1 overexpression is correlated with poor prognosis in epithelial ovarian cancer

OBJECTIVE

To investigate FOXO1 expression in epithelial ovarian cancer (EOC), and to explore its correlation with clinicopathological parameters and prognosis of EOC.

METHODS

Two hundred and sixteen cases of paraffin-embedded EOC and 41 paratumor tissues from 2009 to 2017 that had been pathologically confirmed at the memorial hospital of Sun Yat-sen University were included in this study, and the expression of FOXO1 was performed by immunohistochemistry using a polyclonal antibody specific for FOXO1.

RESULTS

FOXO1 protein expression is associated with Recurrence free and overall survival in EOC patients; In addition, FOXO1 expression is associated with age, FIGO stage, intraperitoneal metastasis, intestinal metastasis, vital status, intraperitoneal recurrence and differentiation grade; Moreover, in a multivariate model FOXO1 overexpression was an independent predictor of poor survival in EOC.

CONCLUSION

FOXO1 may play a candidate oncogenic role in EOC, and FOXO1 is a useful independent prognostic marker in EOC, and it may provide a candidate target therapy in future.

Multifaceted Aspects of Metabolic Plasticity in Human Cholangiocarcinoma: An Overview of Current Perspectives

Cholangiocarcinoma (CCA) is a deadly tumor without an effective therapy. Unique metabolic and bioenergetics features are important hallmarks of tumor cells. Metabolic plasticity allows cancer cells to survive in poor nutrient environments and maximize cell growth by sustaining survival, proliferation, and metastasis. In recent years, an increasing number of studies have shown that specific signaling networks contribute to malignant tumor onset by reprogramming metabolic traits. Several evidences demonstrate that numerous metabolic mediators represent key-players of CCA progression by regulating many signaling pathways. Besides the well-known Warburg effect, several other different pathways involving carbohydrates, proteins, lipids, and nucleic acids metabolism are altered in CCA. The goal of this review is to highlight the main metabolic processes involved in the cholangio-carcinogeneis that might be considered as potential novel druggable candidates for this disease.

Nintedanib inhibits intrahepatic cholangiocarcinoma aggressiveness via suppression of cytokines extracted from activated cancer-associated fibroblasts

Background

Intrahepatic cholangiocarcinoma (ICC) is a malignancy that is challenging to treat. Fibroblasts in ICC tissues have been identified as cancer-associated fibroblasts (CAFs) that promote the malignant behaviour of ICC cells. An antifibrotic drug nintedanib has been reported to suppress activated hepatic stellate cells in liver fibrosis.

Methods

We investigated whether nintedanib could suppress the cancer-promoting effect of CAFs derived from ICC tissues in vitro and in vivo.

Results

CAFs promoted the proliferation and invasion of ICC cells. Nintedanib suppressed activated CAFs expressing α-smooth muscle actin (α-SMA) and inhibited the ICC-promoting effects of CAFs. Nintedanib greatly reduced the levels of cancer-promoting cytokines, such as interleukin (IL)-6 (IL-6) and IL-8, secreted by CAFs. An in vivo study demonstrated that nintedanib reduced xenografted ICC growth and activated CAFs expressing α-SMA, and that combination therapy with nintedanib and gemcitabine against CAFs and ICC cells showed the strongest inhibition of tumour growth compared with the control and single-treatment groups.

Conclusions

Nintedanib inhibited the cancer-promoting effect of CAFs via the suppression of CAF activation and secretion of cancer-promoting cytokines. Our findings suggest that therapeutic strategies combining conventional cytotoxic agents with nintedanib targeting CAFs are promising for overcoming refractory ICC with activated CAFs.

Thrombospondin-1 Exacerbates Acute Liver Failure and Hepatic Encephalopathy Pathology in Mice by Activating Transforming Growth Factor β1

Severe hepatic insults can lead to acute liver failure and hepatic encephalopathy (HE). Transforming growth factor β1 (TGFβ1) has been shown to contribute to HE during acute liver failure; however, TGFβ1 must be activated to bind its receptor and generate downstream effects. One protein that can activate TGFβ1 is thrombospondin-1 (TSP-1). Therefore, the aim of this study was to assess TSP-1 during acute liver failure and HE pathogenesis. C57Bl/6 or TSP-1 knockout (TSP-1-/-) mice were injected with azoxymethane (AOM) to induce acute liver failure and HE. Liver damage, neurologic decline, and molecular analyses of TSP-1 and TGFβ1 signaling were performed. AOM-treated mice had increased TSP-1 and TGFβ1 mRNA and protein expression in the liver. TSP-1-/- mice administered AOM had reduced liver injury as assessed by histology and serum transaminase levels compared with C57Bl/6 AOM-treated mice. TSP-1-/- mice treated with AOM had reduced TGFβ1 signaling that was associated with less hepatic cell death as assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and cleaved caspase 3 expression. TSP-1-/- AOM-treated mice had a reduced rate of neurologic decline, less cerebral edema, and a decrease in microglia activation in comparison with C57Bl/6 mice treated with AOM. Taken together, TSP-1 is an activator of TGFβ1 signaling during AOM-induced acute liver failure and contributes to both liver pathology and HE progression.

Inhibition of PI3K/AKT/mTOR and MAPK signaling pathways decreases progranulin expression in ovarian clear cell carcinoma (OCCC) cell line: a potential biomarker for therapy response to signaling pathway inhibitors

Patients with advanced stage ovarian clear cell carcinoma (OCCC) have a poor prognosis due to resistance to conventional platinum chemotherapy. Recent studies have demonstrated that PI3K/AKT/mTOR and ERK1/2 signaling pathways are involved in this chemoresistance. Progranulin (PGRN) overexpression contributes to cisplatin resistance of epithelial ovarian cancer cell lines. Also, PGRN expression is regulated by AKT/mTOR and ERK1/2 signaling pathways in different cell types. Thus, the present study was designed to identify if PGRN expression is regulated by AKT, mTOR, and ERK1/2 signaling pathways in the OCCC cell line TOV-21G. Cultured TOV-21G cells were incubated with different concentrations of pharmacological cell signaling inhibitors. PGRN expression and phosphorylation of ERK1/2, AKT, and mTOR were assessed by Western blotting. Inhibition of AKT, mTOR, and ERK1/2 significantly reduced PGRN expression. Cell viability was not affected, while cell proliferation significantly decreased with all inhibitors used in this study. These observations demonstrated that inhibition of PI3K/AKT/mTOR and ERK1/2 signaling pathways reduces PGRN expression in TOV-21G cells. Thus, PGRN could be considered as a candidate for explaining the high resistance to platinum-based treatment and a potential biomarker for therapy response to cell signaling inhibitors in patients with OCCC.

M2-polarized tumor-associated macrophages promote epithelial-mesenchymal transition via activation of the AKT3/PRAS40 signaling pathway in intrahepatic cholangiocarcinoma

Tumor-associated macrophages (TAMs) have been considered as a major component of the tumor microenvironment. However, the crosstalk between M2-polarized tumor-associated macrophages (M2-TAMs) and intrahepatic cholangiocarcinoma (ICC) remains undetermined. In the present study, we aimed to clarify the role of M2-TAMs in ICC and the underlying mechanism. The in vitro assay demonstrated M2-TAMs promoted epithelial-mesenchymal transition (EMT) of ICC cells, resulting in enhanced cell invasion and metastasis ability. Moreover, M2-TAMs modulated the microenvironment of ICC by increasing the secretion of cytokines (GM-CSF, tumor necrosis factor-α [TNF-α], ICAM-1, interleukin-6 [IL-6], etc) and chemokines (CCL1, CCL3, etc). In addition, p-AKT (Ser473) and p-PRAS40 (Thr246) were upregulated in ICC cells when cocultured with M2-TAMs or treated with M2-TAMs secreted core cytokines (GM-CSF, TNF-α, ICAM-1, and IL-6). Consistently, AKT3 silencing (but not AKT1 silencing and AKT2 silencing) markedly inhibited phosphorylation of AKT and PRAS40 of ICC cells and inhibited the EMT process when cocultured with M2-TAMs. Taken together, the current data indicated that M2-TAMs promoted ICC cells EMT, partially through increasing secretion of cytokines and chemokines, thus modulating the microenvironment and activating the AKT3/PRAS40 signaling pathway.

Progranulin attenuates liver fibrosis by downregulating the inflammatory response

Progranulin (PGRN) is a cysteine-rich secreted protein expressed in endothelial cells, immune cells, neurons, and adipocytes. It was first identified for its growth factor-like properties, being implicated in tissue remodeling, development, inflammation, and protein homeostasis. However, these findings are controversial, and the role of PGRN in liver disease remains unknown. In the current study, we examined the effect of PGRN in two different models of chronic liver disease, methionine‐choline‐deficient diet (MCD)-induced non-alcoholic steatohepatitis (NASH) and carbon tetrachloride (CCl4)-induced liver fibrosis. To induce long-term expression of PGRN, PGRN-expressing adenovirus was delivered via injection into the tibialis anterior. In the CCl4-induced fibrosis model, PGRN showed protective effects against hepatic injury, inflammation, and fibrosis via inhibition of nuclear transcription factor kappa B (NF-κB) phosphorylation. PGRN also decreased lipid accumulation and inhibited pro-inflammatory cytokine production and fibrosis in the MCD-induced NASH model. In vitro treatment of primary macrophages and Raw 264.7 cells with conditioned media from hepatocytes pre-treated with PGRN prior to stimulation with tumor necrosis factor (TNF)-α or palmitate decreased their expression of pro-inflammatory genes. Furthermore, PGRN suppressed inflammatory and fibrotic gene expression in a cell culture model of hepatocyte injury and primary stellate cell activation. These observations increase our understanding of the role of PGRN in liver injury and suggest PGRN delivery as a potential therapeutic strategy in chronic inflammatory liver disease.

GATA1 gene silencing inhibits invasion, proliferation and migration of cholangiocarcinoma stem cells via disrupting the PI3K/AKT pathway

Background/aims: Intrahepatic cholangiocarcinoma (CCA) is the second most prevalent type primary liver malignancy, accompanied by an increasing global incidence and mortality rate. Research has documented the contribution of the GATA binding protein-1 (GATA1) in the progression of liver cancer. Here, we aim to investigate the role of GATA1 in CCA stem cells via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway.

Methods: Initially, microarray-based gene expression profiling was employed to identify the differentially expressed genes associated with CCA. Subsequently, an investigation was conducted to explore the potential biological significance behind the silencing of GATA1 and the regulatory mechanism between GATA1 and PI3K/AKT pathway. CCA cell lines QBC-939 and RBE were selected and treated with siRNA against GATA1 or/and a PI3K/AKT pathway inhibitor LY294002. In vivo experiment was also conducted to confirm in vitro findings.

Results: GATA1 exhibited higher expression in CCA samples and was predicted to affect the progression of CCA through blockade of the PI3K/AKT pathway. siRNA-mediated downregulation of GATA1 and LY294002 treatment resulted in reduced proliferation, migration and invasion abilities of CCA stem cells, together with impeded tumor growth, and led to increased cell apoptosis and primary cilium expression. Additionally, the siRNA-mediated GATA1 downregulation had an inhibitory effect on the PI3K/AKT pathway. LY294002 was manifested to enhance the inhibitory effects of GATA1 inhibition on CCA progression. These in vitro findings were reproduced in vivo on siRNA against GATA1 or LY294002 injected nude mice.

Conclusion: Altogether, the present study highlighted that downregulation of GATA1 via blockade of the PI3K/AKT pathway could inhibit the CCA stem cell proliferation, migration and invasion, and tumor growth, and promote cell apoptosis, primary cilium expression.

Dissecting the Prognostic Significance and Functional Role of Progranulin in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is known for its strong dependency on the tumor microenvironment. We found progranulin (GRN), a protein that has been linked to inflammation and cancer, to be upregulated in the serum of CLL patients compared to healthy controls, and increased GRN levels to be associated with an increased hazard for disease progression and death. This raised the question of whether GRN is a functional driver of CLL. We observed that recombinant GRN did not directly affect viability, activation, or proliferation of primary CLL cells in vitro. However, GRN secretion was induced in co-cultures of CLL cells with stromal cells that enhanced CLL cell survival. Gene expression profiling and protein analyses revealed that primary mesenchymal stromal cells (MSCs) in co-culture with CLL cells acquire a cancer-associated fibroblast-like phenotype. Despite its upregulation in the co-cultures, GRN treatment of MSCs did not mimic this effect. To test the relevance of GRN for CLL in vivo, we made use of the Eμ-TCL1 CLL mouse model. As we detected strong GRN expression in myeloid cells, we performed adoptive transfer of Eμ-TCL1 leukemia cells to bone marrow chimeric Grn-/- mice that lack GRN in hematopoietic cells. Thereby, we observed that CLL-like disease developed comparable in Grn-/- chimeras and respective control mice. In conclusion, serum GRN is found to be strongly upregulated in CLL, which indicates potential use as a prognostic marker, but there is no evidence that elevated GRN functionally drives the disease.

Elevated circulating TGFβ1 during acute liver failure activates TGFβR2 on cortical neurons and exacerbates neuroinflammation and hepatic encephalopathy in mice

BACKGROUND

Acute liver failure resulting from drug-induced liver injury can lead to the development of neurological complications called hepatic encephalopathy (HE). Hepatic transforming growth factor beta 1 (TGFβ1) is upregulated due to liver failure in mice and inhibiting circulating TGFβ reduced HE progression. However, the specific contributions of TGFβ1 on brain cell populations and neuroinflammation during HE are not known. Therefore, the aim of this study was to characterize hepatic and brain TGFβ1 signaling during acute liver failure and its contribution to HE progression using a combination of pharmacological and genetic approaches.

METHODS

C57Bl/6 or neuron-specific transforming growth factor beta receptor 2 (TGFβR2) null mice (TGFβR2^ΔNeu) were treated with azoxymethane (AOM) to induce acute liver failure and HE. The activity of circulating TGFβ1 was inhibited in C57Bl/6 mice via injection of a neutralizing antibody against TGFβ1 (anti-TGFβ1) prior to AOM injection. In all mouse treatment groups, liver damage, neuroinflammation, and neurological deficits were assessed. Inflammatory signaling between neurons and microglia were investigated in in vitro studies through the use of pharmacological inhibitors of TGFβ1 signaling in HT-22 and EOC-20 cells.

RESULTS

TGFβ1 was expressed and upregulated in the liver following AOM injection. Pharmacological inhibition of TGFβ1 after AOM injection attenuated neurological decline, microglia activation, and neuroinflammation with no significant changes in liver damage. TGFβR2^ΔNeu mice administered AOM showed no effect on liver pathology but significantly reduced neurological decline compared to control mice. Microglia activation and neuroinflammation were attenuated in mice with pharmacological inhibition of TGFβ1 or in TGFβR2^ΔNeu mice. TGFβ1 increased chemokine ligand 2 (CCL2) and decreased C-X3-C motif ligand 1 (CX3CL1) expression in HT-22 cells and reduced interleukin-1 beta (IL-1ß) expression, tumor necrosis factor alpha (TNFα) expression, and phagocytosis activity in EOC-20 cells.

CONCLUSION

Increased circulating TGFβ1 following acute liver failure results in activation of neuronal TGFβR2 signaling, driving neuroinflammation and neurological decline during AOM-induced HE.

MicroRNA-31 reflects IL-6 expression in cancer tissue and is related with poor prognosis in bile duct cancer

Bile duct cancer is a highly aggressive malignancy wherein early diagnosis is difficult and few treatment options are available. MicroRNA-31 (miR-31) is reported to be related with survival in patients with gastrointestinal cancers; however, the regulatory mechanism of miR-31 and association between miR-31 expression and survival in patients with bile duct cancer cases have not been established. Thus, we evaluated miR-31 expression in bile duct cancer tissues and assessed its relationship with prognosis. Additionally, we examined the effects of several cytokines on miR-31 expression. The study included 81 samples of bile duct cancer tissues. MiR-31 expression in bile duct cancer cells was significantly higher than that in normal bile duct epithelial cells (P = 0.038). There were no significant associations between miR-31 expression and clinical or pathological characteristics, except for tumour size (P = 0.012). In Kaplan-Meier analysis, high miR-31 expression was significantly associated with shorter survival (log-rank test, P = 0.0082). In multivariate Cox regression analysis, high miR-31 expression was significantly associated with prognosis (P = 0.043), independent of clinical or pathological features. Interleukin-6 (IL-6) significantly promoted miR-31 expression and cell proliferation in a dose-dependent manner, and the inhibition of STAT-3 signalling significantly suppressed miR-31 expression and cell proliferation. In conclusion, high expression was significantly associated with poor prognosis in bile duct cancer patients. The IL-6-STAT-3 signalling regulated bile duct cancer cell proliferation and miR-31 expression. Our findings suggest that miR-31 may be a promising biomarker that reflects IL-6 expression in bile duct cancer tissues and predicts poor prognosis.

Molecular Pathogenesis of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinomas are a heterogeneous group of malignancies arising from a number of cells of origin along the biliary tree. Although most cases in Western countries are sporadic, large population-based studies have identified a number of risk factors. This review summarises the evidence behind reported risk factors and current understanding of the molecular pathogenesis of cholangiocarcinoma, with a focus on inflammation and cholestasis as the driving forces in cholangiocarcinoma development.

RISK FACTORS FOR CHOLANGIOCARCINOGENESIS

Cholestatic liver diseases (e.g. primary sclerosing cholangitis and fibropolycystic liver diseases), liver cirrhosis, and biliary stone disease all increase the risk of cholangiocarcinoma. Certain bacterial, viral or parasitic infections such as hepatitis B and C and liver flukes also increase cholangiocarcinoma risk. Other risk factors include inflammatory disorders (such as inflammatory bowel disease and chronic pancreatitis), toxins (e.g. alcohol and tobacco), metabolic conditions (diabetes, obesity and non-alcoholic fatty liver disease) and a number of genetic disorders.

MOLECULAR PATHOGENESIS OF CHOLANGIOCARCINOMA

Regardless of aetiology, most risk factors cause chronic inflammation or cholestasis. Chronic inflammation leads to increased exposure of cholangiocytes to the inflammatory mediators interleukin-6, Tumour Necrosis Factor-ɑ, Cyclo-oxygenase-2 and Wnt, resulting in progressive mutations in tumour suppressor genes, proto-oncogenes and DNA mismatch-repair genes. Accumulating bile acids from cholestasis lead to reduced pH, increased apoptosis and activation of ERK1/2, Akt and NF-κB pathways that encourage cell proliferation, migration and survival. Other mediators upregulated in cholangiocarcinoma include Transforming Growth Factor-β, Vascular Endothelial Growth Factor, Hepatocyte Growth Factor and several microRNAs. Increased expression of the cell surface receptor c-Met, the glucose transporter GLUT-1 and the sodium iodide symporter lead to tumour growth, angiogenesis and cell migration. Stromal changes are also observed, resulting in alterations to the extracellular matrix composition and recruitment of fibroblasts and macrophages that create a microenvironment promoting cell survival, invasion and metastasis.

CONCLUSION

Regardless of aetiology, most risk factors for cholangiocarcinoma cause chronic inflammation and/or cholestasis, leading to the activation of common intracellular pathways that result in reactive cell proliferation, genetic/epigenetic mutations and cholangiocarcinogenesis. An understanding of the molecular pathogenesis of cholangiocarcinoma is vital when developing new diagnostic biomarkers and targeted therapies for this disease.

Progranulin: A conductor of receptors orchestra, a chaperone of lysosomal enzymes and a therapeutic target for multiple diseases

Progranulin (PGRN), a widely expressed glycoprotein with pleiotropic function, has been linked to a host of physiological processes and diverse pathological states. A series of contemporary preclinical disease models and clinical trials have evaluated various therapeutic strategies targeting PGRN, highlighting PGRN as a promising therapeutic target. Herein we summarize available knowledge of PGRN targeting in various kinds of diseases, including common neurological diseases, inflammatory autoimmune diseases, cancer, tissue repair, and rare lysosomal storage diseases, with a focus on the functional domain-oriented drug development strategies. In particular, we emphasize the role of extracellular PGRN as a non-conventional, extracellular matrix bound, growth factor-like conductor orchestrating multiple membrane receptors and intracellular PGRN as a chaperone/co-chaperone that mediates the folding and traffic of its various binding partners.

Targeting the PI3K/AKT/mTOR pathway in biliary tract cancers: A review of current evidences and future perspectives

Biliary tract cancers (BTCs) are a group of invasive neoplasms, with increasing incidence and dismal prognosis. In advanced disease, the standard of care is represented by first-line chemotherapy with cisplatin and gemcitabine. In subsequent lines, no clear recommendations are currently available, highlighting the need for novel therapeutic approaches. The PI3K/AKT/mTOR pathway is a core regulator of cell metabolism, growth and survival, and is involved in BTCs carcinogenesis and progression. Mutations, gene copy number alterations and aberrant protein phosphorylation of PI3K, AKT, mTOR and PTEN have been thoroughly described in BTCs and correlate with poor survival outcomes. Several pre-clinical evidences state the efficacy of PI3K/AKT/mTOR pathway inhibitors in BTCs, both in vitro and in vivo. In the clinical setting, initial studies with rapamycin analogs have shown interesting activity with an acceptable toxicity profile. Novel strategies evaluating AKT and PI3K inhibitors have risen serious safety concerns, pointing out the need for improved patient selection and increased target specificity for the clinical development of these agents, both alone and in combination with chemotherapy. This review extensively describes the role of the PI3K/AKT/mTOR pathway in BTCs and examines the rationale of its targeting in these tumors, with particular focus on clinical activity, toxicities and perspectives on further development of PI3K/AKT/mTOR pathway inhibitors.

Liver Fluke-Associated Biliary Tract Cancer

Cholangiocarcinoma (CCA) is an aggressive cancer arising from epithelial cells of the bile duct. Most patients with CCA have an unresectable tumor at the time of diagnosis. In Western countries, the risk of CCA increases in patients with primary sclerosing cholangitis, whereas liver fluke infection appears to be the major risk factor for CCA in Asian countries. A diagnosis of liver fluke infection often relies on stool samples, including microscopic examination, polymerase chain reaction-based assays, and fluke antigen detection. Tests of serum, saliva and urine samples are also potentially diagnostic. The presence of liver fluke along with exogenous carcinogens magnifies the risk of CCA in people living in endemic areas. The “liver fluke-cholangiocarcinoma” carcinogenesis pathways consist of mechanical damage to the bile duct epithelium, immunopathologic and cellular reactions to the liver fluke’s antigens and excretory/secretory products, liver fluke-induced changes in the biliary tract microbiome and the effects of repeated treatment for liver fluke. A vaccine and novel biomarkers are needed for the primary and secondary prevention of CCA in endemic areas. Importantly, climate change exerts an effect on vector-borne parasitic diseases, and awareness of liver fluke should be enhanced in potentially migrated habitat areas.

Human liver flukes

Liver fluke infections occur in people worldwide. In some low-income regions, a combination of ecological, agricultural, and culinary factors leads to a very high prevalence of infection but, in higher-income regions, infections are uncommon. Infection is associated with substantial morbidity and several liver fluke species are recognised as biological carcinogens. Here, we review the epidemiology, clinical significance, and diagnostic and treatment strategies of human infection with these pathogens.

Granulin epithelin precursor promotes colorectal carcinogenesis by activating MARK/ERK pathway

Background

Granulin epithelin precursor (GEP) is reported to function as a growth factor stimulating proliferation and migration, and conferring chemoresistance in many cancer types. However, the expression and functional roles of GEP in colorectal cancer (CRC) remain elusive. The aim of this study was thus to investigate the clinical significance of GEP in CRC and reveal the molecular mechanism of GEP in CRC initiation and progression.

Methods

The mRNA expression of GEP in CRC cell lines were detected by qRT-PCR. The GEP protein expression was validated by immunohistochemistry in tissue microarray (TMA) including 190 CRC patient samples. The clinicopathological correlation analysis were achieved by GEP expression on TMA. Functional roles of GEP were determined by MTT proliferation, monolayer colony formation, cell invasion and migration and in vivo studies through siRNA/shRNA mediated knockdown assays. The cancer signaling pathway identification was acquired by flow cytometry, western blot and luciferase activity assays.

Results

The mRNA expression of GEP in CRC was significantly higher than it in normal colon tissues. GEP protein was predominantly localized in the cytoplasm and most of the CRC cases demonstrated abundant GEP protein compared with non-tumorous tissues. GEP overexpression was associated with non-rectal location, advanced AJCC stage, regional lymph node and distant metastasis. By Kaplan–Meier survival analysis, GEP abundance served as a prognostic marker for worse survival in CRC patients. GEP knockdown exhibited anti-cancer effect such as inhibiting cell proliferation, monolayer colony formation, cell invasion and migration in DLD-1 and HCT 116 cells and decelerating xenograft formation in nude mice. siGEP also induced G1 cell cycle arrest and apoptosis. Luciferase activity assays further demonstrated GEP activation was involved in MAPK/ERK signaling pathway.

Conclusion

In summary, we compressively delineate the oncogenic role of GEP in colorectal tumorigenesis by activating MAPK/ERK signaling pathway. GEP might serve as a useful prognostic biomarker and therapeutic target for CRC.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1530-7) contains supplementary material, which is available to authorized users.

Resveratrol interrupts the pro-invasive communication between cancer associated fibroblasts and cholangiocarcinoma cells

Cholangiocarcinoma (CCA), the cancer arising from the epithelial cells of bile ducts, is a prototype of inflammatory-driven cancer. Cytokines released by cancer associated fibroblasts (CAFs) play a pivotal role in CCA progression, driving the epigenetic Epithelial-to-Mesenchymal transition and the growth and metastasization of CCA cells. Consistently, the conditioned medium from CCA-derived CAFs further stimulated the secretion of IL-6, and to a lesser extent of IL-8, by CCA cells. CCA has a poor prognosis, because of late diagnosis and of high resistance to radio- and chemo-therapy of CCA cells. Targeting the CAFs and their secretion could be an alternative option. We found that while IL-6 indeed promoted the cell migration of invasive CCA cells, the nutraceutical Resveratrol strongly counteracted this effect both in CCA cells and in immortalized cholangiocytes. More importantly, here we show that Resveratrol has the potential to abrogate the secretion of IL-6 by CAFs. While the conditioned medium from CAFs strongly induced IL-6 mediated motility of CCA cells, the conditioned medium from CAFs pre-treated with Resveratrol completely halted cancer cell motility and reverted the N-to E-cadherin switch in migrating cells. This effect was associated with stimulation of autophagy in the cancer cells. This is the first demonstration that CAFs secretory products directly affect the regulation of autophagy and consequently the behavior of CCA cells, and that a nutraceutical may revert the malignant phenotype of cancer cells by acting on CAFs metabolism and secretion.

Genistein reduces the activation of AKT and EGFR, and the production of IL6 in cholangiocarcinoma cells involving estrogen and estrogen receptors

Cholangiocarcinoma (CCA) is a malignant tumor of the biliary epithelium associated with Opisthorchis viverrini, primary sclerosing cholangitis and hepatitis viral infection. In the global population, men have higher incidence rates for CCA than women; thus, a gender disparity in the progression of chronic inflammation of the biliary duct leading to malignancy may involve the effects of estrogen (E2). Genistein (GE), a prominent phytoestrogen found in soy products, is an estrogen receptor β (ERβ) agonist and a tyrosine kinase inhibitor. The present study investigated the effects of GE on the growth of CCA cells by cell viability assay. The effects on signaling proteins were detected by western blot analysis and ELISA. Gene expression was examined by RT-qPCR. Two human intrahepatic CCA cell lines, HuCCA‑1 and RMCCA‑1, were utilized. GE (50‑200 µM) reduced the viability of the two cell lines, and also inhibited the activation of epidermal growth factor receptor (EGFR) and AKT, as evidenced by decreasing protein levels of phosphorylated (p)-EGFR (Tyr1173) and p‑AKT (Ser473), respectively. GE altered the mitogen‑activated protein kinase signaling cascade by mediating decreased protein levels of p‑p38 and increased protein levels of p‑ERK1/2. GE significantly decreased the levels of interleukin 6 (IL6) and induced the expression of inducible nitric oxide synthase (iNOS). GE also downregulated the expression of p‑ERα (Ser118) protein and ERα mRNA levels. Finally, GE induced the downregulation of the protein levels of ERβ. Of note, E2 deprivation potentiated the GE-induced reduction of p‑EGFR (Tyr1173) and total AKT proteins and production of IL6, and mediated the downregulation of GE-induced iNOS protein. In conclusion, GE inhibited the growth of human CCA cell lines by reducing the activation of EGFR and AKT, and by attenuating the production of IL6. E2 and ER were also involved in the growth-inhibitory effect of GE in CCA cells.

Progranulin concentration in relation to bone mineral density among obese individuals

OBJECTIVE

Adipose tissue, particularly visceral adipose tissue, secretes a variety of cytokines, among which progranulin is a glycoprotein related to the immune system. Along with other secreted proteins, progranulin may be associated with bone mineral density. The aim of this study was to find out whether there are associations between the progranulin and bone mineral density among obese people.

SUBJECTS AND METHODS

This cross-sectional study was conducted on 244 obese participants (aged 22-52). Serum progranulin, high sensitive C-reactive protein, oxidised-low dencity lipoprotein, tumor necrosis factor-α, parathormone, vitamin D, and interleukins of 1 β, 4, 6, 10, 13, and 17 concentrations were measured. Anthropometric measurements, body composition and bone mineral density were also assessed.

RESULTS

Serum progranulin was directly associated with interleukin-6 and interleukin-1β, while it had a negative association with interleukin-17 and tumor necrosis factor-α. We also observed a statistically significant direct association between progranulin concentration and visceral fat, abdominal fat, waist, abdominal and hip circumferences, hip T-score, and Z-score and T-score for the lumbar region. A partial correlation test has also shown a significant positive correlation regarding serum progranulin and the hip Z-score. Moreover, progranulin level is inversely associated with ospteopenia (P = 0.04 and CI: 0.17,0.96).

CONCLUSION

Our study revealed that central obesity may be related to increased progranulin concentration. In addition, progranulin concentration was directly related to bone formation parameters, which indicates the protective effects of progranulin on bone density. Further studies are needed to clarify the exact mechanisms underlying these associations.

FXR-Mediated Cortical Cholesterol Accumulation Contributes to the Pathogenesis of Type A Hepatic Encephalopathy

BACKGROUND & AIMS

Hepatic encephalopathy is a serious neurologic complication of acute and chronic liver diseases. We previously showed that aberrant bile acid signaling contributes to the development of hepatic encephalopathy via farnesoid X receptor (FXR)-mediated mechanisms in neurons. In the brain, a novel alternative bile acid synthesis pathway, catalyzed by cytochrome p450 46A1 (Cyp46A1), is the primary mechanism by which the brain regulates cholesterol homeostasis. The aim of this study was to determine if FXR activation in the brain altered cholesterol homeostasis during hepatic encephalopathy.

METHODS

Cyp7A1^-/- mice or C57Bl/6 mice pretreated with central infusion of FXR vivo morpholino, 2-hydroxypropyl-β-cyclodextrin, or fed a cholestyramine-supplemented diet were injected with azoxymethane (AOM). Cognitive and neuromuscular impairment as well as liver damage and expression of Cyp46A1 were assessed using standard techniques. The subsequent cholesterol content in the frontal cortex was measured using commercially available kits and by Filipin III and Nile Red staining.

RESULTS

There was an increase in membrane-bound and intracellular cholesterol in the cortex of mice treated with AOM that was associated with decreased Cyp46A1 expression. Strategies to inhibit FXR signaling prevented the down-regulation of Cyp46A1 and the accumulation of cholesterol. Treatment of mice with 2-hydroxypropyl-β-cyclodextrin attenuated the AOM-induced cholesterol accumulation in the brain and the cognitive and neuromuscular deficits without altering the underlying liver pathology.

CONCLUSIONS

During hepatic encephalopathy, FXR signaling increases brain cholesterol and contributes to neurologic decline. Targeting cholesterol accumulation in the brain may be a possible therapeutic target for the management of hepatic encephalopathy.

Tumor necrosis factor receptor 2/AKT and ERK signaling pathways contribute to the switch from fibroblasts to CAFs by progranulin in microenvironment of colorectal cancer

Cancer associated fibroblasts (CAFs) are a crucial cellular component in tumor microenvironment and could promote tumor progression. CAFs are usually derived from resident fibroblasts, which undergoing an activated process stimulated by tumor cells. However, the agents and mechanism driving this switch have not yet been elucidated. Progranulin (PGRN), a well acknowledged secreted glycoprotein, could promote proliferation and angiogenesis of colorectal cancer (CRC) cells, and high expression of PGRN correlated with patient poor prognosis. Whether PGRN has effects on the function of stromal fibroblasts is unknown. Herein we found that there was a positive correlation between PGRN expression of CRC cells and expressions of smooth muscle actin α (α-SMA) on CAFs in CRC patient tissues. PGRN/α-SMA co-expression was positively correlated with CRC patient poor prognosis. Co-cultured with CRC cells or human recombinant PGRN (rPGRN), the expression of Ki67, fibroblast activation protein (FAP) and α-SMA in fibroblasts were all up-regulated significantly, accompanying with elevated cellular proliferation, migration and contraction. Whilst co-cultured with PGRN-silenced CRC cells, these functions were down-regulated. Studies of the underlying molecular mechanism demonstrated that either tumor necrosis factor receptor 2 (TNFR2)/Akt or the extracellular regulated kinase (ERK) signaling pathway contributed to modulate of Ki67, FAP, and α-SMA expression, and correlated to abilities of proliferation, migration and contraction in fibroblasts. In conclusion, PGRN plays an important role in activation of CRC fibroblasts, which may be taken as a prospective target of CRC therapy.

Growth factor progranulin promotes tumorigenesis of cervical cancer via PI3K/Akt/mTOR signaling pathway

Progranulin (PGRN) is an autocrine growth factor with tumorigenic roles in various tumors including cervical cancer. In this study, we investigated mammalian target of rapamycin (mTOR) signaling in response to PGRN induction and the contribution of the PGRN-stimulated PI3K/Akt/mTOR signaling pathway in the transformation and progression of cervical cancer. Here we identified a strong linkage between PGRN and phosphorylated-mTOR in cervical cancer tissues. PGRN promoted the phosphorylation of mTOR and activated mTOR signaling in human cervical mucosa epithelial cells and cervical cancer cells, and TNFR2 was needed for PGRN-stimulated mTOR signaling. Inhibition of mTOR signaling with rapamycin decreased PGRN-stimulated protein synthesis, transformation and proliferation of cervical cells in vitro, and tumor formation and growth in vivo. Thus, our findings update the signal transduction pathways of PGRN by suggesting that mTOR signaling contributes to PGRN-stimulated carcinogenesis of cervical cancer. Inhibition of PGRN/PI3K/Akt/mTOR signaling may be targeted in treatment of cervical cancer.

Progranulin facilitates the increase of platelet count in immune thrombocytopenia

INTRODUCTION

Progranulin (PGRN) is emerging as a critical immune mediator involved in a variety of autoimmune disorders. However, its role in immune thrombocytopenia (ITP) remains unclear.

MATERIALS AND METHODS

In this study, the enzyme-linked immunosorbent assay was used for determining the plasma levels of PGRN in ITP patients vs. healthy controls. In addition, the role of PGRN in ITP was investigated in two kinds of ITP murine models. Further, we explored whether PGRN functioned by affecting the number of T regulatory cells (Tregs) using flow cytometry.

RESULTS

We first observed that plasma levels of PGRN were significantly elevated in ITP patients (n = 52) compared to healthy controls (n = 40), and the levels of PGRN declined in patients after receiving treatment. Additionally, we found a negative correlation between plasma PGRN levels and platelet count of ITP patients, suggesting that PGRN is involved in the pathogenesis of ITP. PGRN deficiency further decreased platelet count in a passive-transfer ITP murine model. By contrast, administration of recombinant PGRN increased platelet count in SCID mice with chronic ITP. Meanwhile, PGRN deficiency impaired proliferation of Tregs in the passive transfer ITP murine model. These data suggest that PGRN may exert a protective role in ITP by promoting Treg proliferation.

CONCLUSION

Our study revealed a new regulator involved in the pathogenesis of ITP and provided a potential strategy for management of ITP.

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.

Higher levels of progranulin in cerebrospinal fluid of patients with lymphoma and carcinoma with CNS metastasis

Assessing central nervous system (CNS) involvement in patients with lymphoma or carcinoma is important in determining therapy and prognosis. Progranulin (PGRN) is a secreted glycosylated protein with roles in cancer growth and survival; it is highly expressed in aggressive cancer cell lines and specimens from many cancer types. We examined PRGN levels by Enzyme Immuno-Assay (EIA) in cerebrospinal fluid (CSF) samples from 230 patients, including 18 with lymphoma [12 with CNS metastasis (CNS⁺); 6 without CNS metastasis (CNS^-)], 21 with carcinomas (10 CNS⁺; 11 CNS^-), and 191 control patients with non-cancer neurological diseases, and compared PRGN levels among these disease groups. Median CSF PGRN levels in the CNS⁺ lymphoma group were significantly higher than in the CNS^- lymphoma and control non-cancer groups; and were also significantly higher in the CNS⁺ carcinoma group than in the CNS^- carcinoma and control groups, except for patients with infectious neurological disorders. Receiver operating characteristic curve analyses revealed that CSF PGRN levels distinguished CNS⁺ lymphoma from CNS^- lymphoma and non-cancer neurological diseases [area under curve (AUC): 0.969]; and distinguished CNS⁺ carcinomas from CNS^- carcinomas and non-cancer neurological diseases (AUC: 0.918). We report here, for the first time, that CSF PGRN levels are higher in patients with CNS⁺ lymphoma and carcinomas compared to corresponding CNS^- diseases. This would imply that measuring CSF PGRN levels could be used to monitor CNS⁺ lymphoma and metastasis.

Opisthorchiasis-Induced Cholangiocarcinoma: How Innate Immunity May Cause Cancer

Innate, inflammatory responses towards persistent Opisthorchis viverrini (OV) infection are likely to contribute to the development of cholangiocarcinoma (CCA), a liver cancer that is rare in the West but prevalent in Greater Mekong Subregion countries in Southeast Asia. Infection results in the infiltration of innate immune cells into the bile ducts and subsequent activation of inflammatory immune responses that fail to clear OV but instead may damage local tissues within the bile ducts. Not all patients infected with OV develop CCA, and so tumourigenesis may be dependent on multiple factors including the magnitude of the inflammatory response that is activated in infected individuals. The purpose of this review is to summarize how innate immune responses may promote tumourigenesis following OV infection and if such responses can be used to predict CCA onset in OV-infected individuals. It also hypothesizes on the role that Helicobacterspp., which are associated with liver fluke infections, may play in activation of the innate the immune system to promote tissue damage and persistent inflammation leading to CCA.