The communication between tumor-derived elements and stroma in the metastatic niche has a critical role in facilitating cancer metastasis. Yet, the mechanisms tumor cells use to control metastatic ...niche formation are not fully understood. Here we report that in the lung metastatic niche, high-metastatic hepatocellular carcinoma (HCC) cells exhibit a greater capacity to convert normal fibroblasts to cancer-associated fibroblasts (CAFs) than low-metastatic HCC cells. We show high-metastatic HCC cells secrete exosomal miR-1247-3p that directly targets B4GALT3, leading to activation of β1-integrin-NF-κB signaling in fibroblasts. Activated CAFs further promote cancer progression by secreting pro-inflammatory cytokines, including IL-6 and IL-8. Clinical data show high serum exosomal miR-1247-3p levels correlate with lung metastasis in HCC patients. These results demonstrate intercellular crosstalk between tumor cells and fibroblasts is mediated by tumor-derived exosomes that control lung metastasis of HCC, providing potential targets for prevention and treatment of cancer metastasis.
Neutrophils are the largest population of circulating leukocytes and the first responder against invading pathogens or other danger signals. Sophisticated machineries help them play critical roles in ...immunity and inflammation, including phagocytosis, superoxide production, cytokine and chemokine production, degranulation, and formation of neutrophil extracellular traps (NETs). After maturation and release from the bone marrow, neutrophils migrate to inflamed tissues in response to many stimuli. Increasing evidences indicate that neutrophils are critically involved in the pathogenesis of liver diseases, including liver cancer, thus making them promising target for the treatment of liver diseases. Here, we would like to provide the latest finding about the role of neutrophils in liver diseases and discuss the potentiality of neutrophils as target for liver diseases.
The AMP-activated protein kinase (AMPK) serves as an energy sensor in eukaryotic cells and occupies a central role in linking metabolism and cancer development. However, the phosphorylation status of ...AMPK and its therapeutic value in human hepatocellular carcinoma (HCC) remain unclear.
The phosphorylation status of AMPK (Thr172) was determined by immunoblotting and immunostaining in specimens from 273 patients with HCC (including 253 patients with hepatitis B virus -related HCC). Kaplan-Meier survival analysis was used to determine the correlation with prognosis. The effects of therapeutic metformin/AMPK activation were assessed in cultured human HCC cell lines and primary HCC cells in vitro and in xenograft tumors model in vivo. To define the mechanisms of anticancer effects of metformin, we examined its influence on AMPK activation and NF-κB pathway.
AMPK is dysfunctional in patients with HCC, and low p-AMPK staining is correlated with aggressive clinicopathologic features and poor prognosis. Activation of AMPK by metformin not only inhibited HCC cells growth in vitro and in vivo, but also augmented cisplatin-induced growth inhibition in HCC cells. Knockdown of AMPKα expression can greatly decrease the inhibitory effect of metformin, indicating that AMPK activation is required for the anticancer action of metformin. Mechanistically, metformin/AMPK activation inhibited NF-κB signaling through upregulation of IκBα. Activation of NF-κB signaling by ectopic expression of P65 or overexpression of an undegradable mutant form of IκBα attenuated the anticancer effects of metformin.
These results present novel insight into a critical role of AMPK in HCC progression. Anticancer effects of therapeutic metformin/AMPK activation unravel metformin's potential in treatment of HCC.
Fibrosis and cancer represent two major complications of chronic liver disease. MicroRNAs have been implicated in the development of fibrosis and cancer, thus constituting potential therapeutic ...targets. Here, we investigated the role of microRNA‐21 (miR‐21), a microRNA that has been implicated in the development of fibrosis in multiple organs and has also been suggested to act as an “oncomir.” Accordingly, miR‐21 was the microRNA that showed the strongest up‐regulation in activated hepatic stellate cells (HSCs) in multiple models of fibrogenesis, with an 8‐fold to 24‐fold induction compared to quiescent HSCs. However, miR‐21 antisense inhibition did not suppress the activation of murine or human HSCs in culture or in liver slices. Moreover, genetic deletion of miR‐21 in two independently generated knockout mice or miR‐21 antisense inhibition did not alter HSC activation or liver fibrosis in models of toxic and biliary liver injury. Despite a strong up‐regulation of miR‐21 in injury‐associated hepatocellular carcinoma and in cholangiocarcinoma, miR‐21 deletion or antisense inhibition did not reduce the development of liver tumors. As inhibition of the most up‐regulated microRNA did not affect HSC activation, liver fibrosis, or fibrosis‐associated liver cancer, we additionally tested the role of microRNAs in HSCs by HSC‐specific Dicer deletion. Although Dicer deletion decreased microRNA expression in HSCs and altered the expression of select genes, it only exerted negligible effects on HSC activation and liver fibrosis. Conclusion: Genetic and pharmacologic manipulation of miR‐21 does not inhibit the development of liver fibrosis and liver cancer. Moreover, suppression of microRNA synthesis does not significantly affect HSC phenotype and activation. (Hepatology 2018;67:2414‐2429).
Cancer-associated fibroblasts (CAF) are a poorly characterized cell population in the context of liver cancer. Our study investigates CAF functions in intrahepatic cholangiocarcinoma (ICC), a highly ...desmoplastic liver tumor. Genetic tracing, single-cell RNA sequencing, and ligand-receptor analyses uncovered hepatic stellate cells (HSC) as the main source of CAF and HSC-derived CAF as the dominant population interacting with tumor cells. In mice, CAF promotes ICC progression, as revealed by HSC-selective CAF depletion. In patients, a high panCAF signature is associated with decreased survival and increased recurrence. Single-cell RNA sequencing segregates CAF into inflammatory and growth factor-enriched (iCAF) and myofibroblastic (myCAF) subpopulations, displaying distinct ligand-receptor interactions. myCAF-expressed hyaluronan synthase 2, but not type I collagen, promotes ICC. iCAF-expressed hepatocyte growth factor enhances ICC growth via tumor-expressed MET, thus directly linking CAF to tumor cells. In summary, our data demonstrate promotion of desmoplastic ICC growth by therapeutically targetable CAF subtype-specific mediators, but not by type I collagen.
Display omitted
•The majority of CAF in ICC are derived from hepatic stellate cells•Inflammatory CAF promote ICC through HGF and its receptor MET•myCAF promote ICC through Has2/hyaluronic acid•CAF-derived type I collagen contributes to stiffness but does not promote ICC growth
Intrahepatic cholangiocarcinoma (ICC) is an extraordinarily stiff liver tumor due to abundant scar-forming cancer-associated fibroblasts (CAF). Here, Affo et al. determine the origin and functions of CAF, and uncover distinct CAF subsets, promoting ICC growth via different therapeutically targetable mediators. Thus, CAF and their mediators may serve as therapeutic targets for ICC.
Hepatocellular carcinoma (HCC) is a prototype of inflammation‐associated cancer. Oncoprotein Gankyrin, which mostly increases in HCC, plays a critical role in HCC development and metastasis. However, ...the exact mechanism of Gankyrin up‐regulation in HCC remains unclear. A Gankyrin luciferase reporter was developed to screen a potential regulator for Gankyrin from a list of proinflammatory cytokines, and interleukin (IL)‐1β was found as one of its activators. In clinical premalignant and malignant liver disease samples, enhanced IL‐1β/interleukin‐1 receptor‐associated kinase 1 (IRAK‐1) signaling accompanied by increased Gankyrin was observed. Lower expression of Gankyrin and phospho‐IRAK‐1 are favorable prognostic markers for HCC. A similar correlation was observed in the diethylnitrosamine (DEN) model of rat hepatocarcinogenesis. The results from Gankyrin reporter activity, real‐time polymerase chain reaction, or immunoblotting further confirmed the up‐regulation of Gankyrin by IL‐1β/IRAK‐1 inflammatory signaling. Moreover, a series of Gankyrin's truncated reporters were constructed, and electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) were performed to analyze the properties of Gankyrin promoter. Mechanistically, the core promoter of Gankyrin contains the binding site of nuclear factor Y (NF‐Y) family members, which can recruit histone acetyltransferase coactivator E1A‐binding protein p300 (p300) or CREB‐binding protein (CBP) to promote Gankyrin transcription. Conversely, knockdown of NF‐Y, p300, or CBP inhibits Gankyrin expression. IL‐1β stimulation causes sequential phosphorylation of IRAK‐1, c‐Jun N‐terminal kinase (JNK), and p300 and enhances recruitment of the p300/CBP/NF‐Y complex to Gankyrin promoter. Inhibition of phospho‐JNK impairs IL‐1β/IRAK‐1 signaling‐mediated up‐regulation of Gankyrin. Conclusion: The finding of IL‐1β/IRAK‐1 signaling promoting Gankyrin expression through JNK and NF‐Y/p300/CBP complex provides a fresh view on inflammation‐enhanced hepatocarcinogenesis. (Hepatology 2015;61:585‐597)
Hepatocellular carcinoma (HCC) is a prototype of inflammation-associated cancer. Oncoprotein Gankyrin, which mostly increases in HCC, plays a critical role in HCC development and metastasis. However, ...the exact mechanism of Gankyrin up-regulation in HCC remains unclear. A Gankyrin luciferase reporter was developed to screen a potential regulator for Gankyrin from a list of proinflammatory cytokines, and interleukin (IL)-1beta was found as one of its activators. In clinical premalignant and malignant liver disease samples, enhanced IL-1beta/interleukin-1 receptor-associated kinase 1 (IRAK-1) signaling accompanied by increased Gankyrin was observed. Lower expression of Gankyrin and phospho-IRAK-1 are favorable prognostic markers for HCC. A similar correlation was observed in the diethylnitrosamine (DEN) model of rat hepatocarcinogenesis. The results from Gankyrin reporter activity, real-time polymerase chain reaction, or immunoblotting further confirmed the up-regulation of Gankyrin by IL-1beta/IRAK-1 inflammatory signaling. Moreover, a series of Gankyrin's truncated reporters were constructed, and electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) were performed to analyze the properties of Gankyrin promoter. Mechanistically, the core promoter of Gankyrin contains the binding site of nuclear factor Y (NF-Y) family members, which can recruit histone acetyltransferase coactivator E1A-binding protein p300 (p300) or CREB-binding protein (CBP) to promote Gankyrin transcription. Conversely, knockdown of NF-Y, p300, or CBP inhibits Gankyrin expression. IL-1beta stimulation causes sequential phosphorylation of IRAK-1, c-Jun N-terminal kinase (JNK), and p300 and enhances recruitment of the p300/CBP/NF-Y complex to Gankyrin promoter. Inhibition of phospho-JNK impairs IL-1beta/IRAK-1 signaling-mediated up-regulation of Gankyrin. Conclusion: The finding of IL-1beta/IRAK-1 signaling promoting Gankyrin expression through JNK and NF-Y/p300/CBP complex provides a fresh view on inflammation-enhanced hepatocarcinogenesis. (Hepatology 2015;61:585-597)
c-Met, the tyrosine-kinase receptor for hepatocyte growth factor, plays a critical role in the tumorigenesis of hepatocellular carcinoma (HCC). However, the underlying mechanism remains incompletely ...understood. The mature c-Met protein p190Metαβ (consists of a α subunit and a β subunit) is processed from pro-Met. Here we show that pro-Met is processed into p190MetNC by sarco/endoplasmic reticulum calcium-ATPase (SERCA) inhibitor thapsigargin. p190MetNC compensates for the degradation of p190Metαβ and protects human HCC cells from apoptosis mediated by endoplasmic reticulum (ER) stress. In comparison with p190Metαβ, p190MetNC is not cleaved and is expressed as a single-chain polypeptide. Thapsigargin-initiated p190MetNC expression depends on the disturbance of ER calcium homeostasis. Once induced, p190MetNC is activated independent of hepatocyte growth factor engagement. p190MetNC contributes to sustained high basal activation of c-Met downstream pathways during ER calcium disturbance-mediated ER stress. Both p38 MAPK-promoted glucose-regulated protein 78 (GRP78) expression and sustained high basal activation of PI3K/Akt and MEK/ERK are involved in the cytoprotective function of p190MetNC. Importantly, the expression of p190MetNC is detected in some HCC cases. Taken together, these data provide a potential mechanism to explain how c-Met promotes HCC cells survival in response to ER stress. We propose that context-specific processing of c-Met protein is implicated in HCC progression in stressful microenvironments.
Background: Both ER stress and c-Met are implicated in the tumorigenesis of HCC.
Results: ER calcium disturbance-induced p190MetNC expression inhibits ER stress-mediated apoptosis.
Conclusion: p190MetNC, but not p190Metαβ, plays a critical role in promoting HCC cells survival under ER stress.
Significance: We identify a novel biochemical mechanism by which c-Met ensures HCC cell survival under stress conditions.
The microbiome is a diverse and adaptive ecosystem whose composition is influenced by nutrition, lifestyle, gender, age,and diurnal changes. This chapter analyzes key pathways that regulate ...interactions between host and gut microbiota in the context of liver disease. It reviews the contribution of the gut microbiota types of liver disease. The chapter also reviews the therapeutic opportunities to target the microbiota–liver axis for the prevention or treatment of liver disease. Interactions between the gut microbiota and the immune system are bidirectional. Alcoholic liver disease is a spectrum ranging from hepatic steatosis to cirrhosis and alcoholic hepatitis. Fibrosis is the main determinant of mortality in non‐alcoholic steatohepatitis, as well as other types of chronic liver diseases (CLDs). Enrichment or decrease of specific bacteria correlates with the severity of liver dysfunction in cirrhosis. Hepatocellular carcinoma is a long‐term consequence of CLD and predominantly develops in cirrhotic livers.
PDF
