Hepatocarcinoma cells stimulate hepatocyte growth factor secretion in human liver myofibroblasts

A Comparative Study of Serum Angiogenic Biomarkers in Cirrhosis and Hepatocellular Carcinoma

Simple Summary

The progression of liver disease is accompanied by pathological angiogenesis, a prerequisite for the development of HCC. In this paper, we analyzed the clinical significance of serum angiogenic markers VEGF, Ang-1, Ang-2, angiopoietin receptor Tie1/2, HGF, and PECAM-1 in 62 patients with liver disease, out of which 33 were diagnosed with HCC and 29 with liver cirrhosis without signs of neoplasia. Biomarkers levels were investigated as a function of “Model for End-Stage Liver Disease” (MELD) score and Fibrosis Index (FI). HCC patients showed higher HGF levels than ones with cirrhosis, while high Ang-1 levels appeared to have a protective role in HCC as well as prognostic significance; we also found a strong correlation between HGF levels, Ang-2, and VEGF levels, further supporting their role in tumor angiogenesis. Due to the complexity of angiogenesis and the small size of the study group, further investigations are widely desired especially in the era of immunotherapy and HCC-targeted anti-angiogenic drugs.

Abstract

Background: Hepatocellular carcinoma (HCC) is a global health problem associated with chronic liver disease. Its pathogenesis varies according to the underlying etiological factors, although in most cases it develops from liver cirrhosis. The disease progression is accompanied by pathological angiogenesis, which is a prerequisite that favors the development of HCC. Aims: This study aims at contributing to our understanding of the role of angiogenic factors in the progression of liver disease. For this purpose, we evaluate the clinical significance of serum angiogenic markers (VEGF, Ang-1, Ang-2, the angiopoietin receptor Tie1/2, HGF, and PECAM-1) first in cirrhotic and HCC patients separately, and then comparing cirrhotic patients with and without HCC. Materials and Methods: We enrolled 62 patients, out of whom 33 were diagnosed with HCC and 29 with liver cirrhosis without signs of neoplasia. Patients underwent venous blood sampling before and after receiving treatments for the diagnosed disease. Serum markers were evaluated using ELISA assays for Tie1 and the Bio-Plex Multiplex system for the remaining ones. Biomarker levels were investigated as a function of clinical scores for disease staging (MELD and Fibrosis Index, FI). Results: In cirrhotic patients, Ang-1 and Ang-2 correlate with MELD (ρ_Ang-1 = −0.73, p = 2E−5) and FI (ρ_Ang-1 = −0.52, p = 7E−3, ρ_Ang-2 = 0.53, p = 3E−3). A reduction of Ang-2 levels (p = 0.047) and of the Ang-2/Ang-1 ratio (p = 0.031) is observed in cirrhotic patients diagnosed with viral hepatitis after antiviral treatments. In HCC patients, Ang-1 negatively correlates with FI (ρ = −0.63, p = 1E−4), and PECAM-1 positively correlates with MELD (ρ = 0.44, p = 0.01). A significant Ang-1 reduction was observed in deceased patients during the study compared to ones who survived (p = 0.01). In HCC patients, VEGF levels were increased after tumor treatment (p = 0.037). Notably, HGF levels in cirrhotic patients with HCC are significantly raised (p = 0.017) compared to that in those without HCC. Conclusions: Our results suggest that serum angiogenic markers, with emphasis on Ang-1/2, can contribute to the development of quantitative tools for liver disease staging and therapy monitoring. The comparison between cirrhotic patients with and without HCC suggests that HGF levels are potentially useful for monitoring the insurgence of HCC after a cirrhosis diagnosis. High Ang-1 levels in HCC patients appear to have a protective role as well as prognostic significance.

Peritumoral activated hepatic stellate cells are associated with hepatic recurrence for resectable colorectal adenocarcinoma liver metastasis following resection

The formation of the pre-metastatic niche (PMN), which precedes the establishment of tumor lesions, plays a critical role in cancer recurrence and metastasis. Hepatic stellate cells (HSCs), a critical liver stromal cell component, can be induced to facilitate metastasis by modeling liver PMN formation. In the present study, activated HSCs were observed in the peritumor non-cancerous liver tissues (PNLT) colorectal adenocarcinoma liver metastasis (CRALM), and the density of activated HSCs was higher in PNLT compared with that in normal liver tissues (NLT). High density of activated HSC in the PNLT was positively associated with the number of tumor liver metastases (P=0.036), maximum diameter of liver metastases (P=0.002), and recurrence following synchronous radical resection (P=0.003). High density of activated HSCs in the PNLT was identified as a significant and independent prognostic factor for disease-free survival (HR, 2.083; 95% CI, 1.504–2.885; P=0.016) and overall survival (HR, 2.039; 95% CI, 1.312–3.169; P=0.019). Functionally, in vitro assays revealed that activated HSCs facilitated colorectal adenocarcinoma (CRA) cells to colonize the liver. Molecularly, it was demonstrated that the pro-recurrence of activated HSCs depended on paracrine hepatic growth factor. Taken together, the present results showed that high density of activated HSCs in the PNLT was an independent predictor for CRALM recurrence following resection, and they exerted their roles via their effect on CRA cell recruitment and proliferation by paracrine HGF.

Decreased expression of hsa_circ_0003570 in hepatocellular carcinoma and its clinical significance

BACKGROUND

Circular RNAs (circRNAs) constitute a class of non-coding RNAs recently discovered to be widespread and abundant in mammalian cells. However, the expression features of most of circRNAs in hepatocellular carcinoma (HCC) are unraveled. In this study, we focused on hsa_circ_0003570, which was found to be down-regulated in HCC tissues in our previous microarray screening.

METHODS

The hsa_circ_0003570 levels in HCC cell lines, HepG2, SMMC-7721, MHCC97L, MHCC97H, and HCCLM3, and human normal hepatic cell line L02 were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Then, its levels in 107 paired HCC tissues and adjacent non-tumor tissues, 60 liver biopsy samples from patients with chronic liver diseases were detected by qRT-PCR. The receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of hsa_circ_0003570 for HCC.

RESULTS

Hsa_circ_0003570 was not only first found down-regulated in HCC cell lines (P<.001) but also in HCC tissues (P<.001). Moreover, hsa_circ_0003570 was gradually decreased from chronic hepatitis (CH), to liver cirrhosis (LC) and to HCC tissues (P<.01). Its expression levels were significantly correlated with tumor diameter (P=.035), differentiation (P=.013), microvascular invasion (P=.045), Barcelona Clinic Liver Cancer stages (P=.011), tumor-node-metastasis stages (P=.016), and serum alpha-fetoprotein levels (P=.031). The ROC curve demonstrated that hsa_circ_0003570 had poor performance for differentiating HCC from LC and CH, but had relatively good performance for differentiating LC from CH.

CONCLUSIONS

These results indicated that hsa_circ_0003570 expression levels were associated with HCC clinicopathological characteristics.

Higher Matrix Stiffness Upregulates Osteopontin Expression in Hepatocellular Carcinoma Cells Mediated by Integrin β1/GSK3β/β-Catenin Signaling Pathway

Increased stromal stiffness is associated with hepatocellular carcinoma (HCC) development and progression. However, the molecular mechanism by which matrix stiffness stimuli modulate HCC progress is largely unknown. In this study, we explored whether matrix stiffness-mediated effects on osteopontin (OPN) expression occur in HCC cells. We used a previously reported in vitro culture system with tunable matrix stiffness and found that OPN expression was remarkably upregulated in HCC cells with increasing matrix stiffness. Furthermore, the phosphorylation level of GSK3β and the expression of nuclear β-catenin were also elevated, indicating that GSK3β/β-catenin pathway might be involved in OPN regulation. Knock-down analysis of integrin β1 showed that OPN expression and p-GSK3β level were downregulated in HCC cells grown on high stiffness substrate compared with controls. Simultaneously, inhibition of GSK-3β led to accumulation of β-catenin in the cytoplasm and its enhanced nuclear translocation, further triggered the rescue of OPN expression, suggesting that the integrin β1/GSK-3β/β-catenin pathway is specifically activated for matrix stiffness-mediated OPN upregulation in HCC cells. Tissue microarray analysis confirmed that OPN expression was positively correlated with the expression of LOX and COL1. Taken together, high matrix stiffness upregulated OPN expression in HCC cells via the integrin β1/GSK-3β/β-catenin signaling pathway. It highlights a new insight into a pathway involving physical mechanical signal and biochemical signal molecules which contributes to OPN expression in HCC cells.

Hepatic stellate cells: central modulators of hepatic carcinogenesis

Hepatocellular carcinoma (HCC) represents the second most common cause of cancer-related death worldwide, and is increasing in incidence. Currently, our therapeutic repertoire for the treatment of HCC is severely limited, and therefore effective new therapies are urgently required. Recently, there has been increasing interest focusing on the cellular and molecular interactions between cancer cells and their microenvironment. HCC represents a unique opportunity to study the relationship between a diseased stroma and promotion of carcinogenesis, as 90 % of HCCs arise in a cirrhotic liver. Hepatic stellate cells (HSC) are the major source of extracellular proteins during fibrogenesis, and may directly, or via secreted products, contribute to tumour initiation and progression. In this review we explore the complex cellular and molecular interplay between HSC biology and hepatocarcinogenesis. We focus on the molecular mechanisms by which HSC modulate HCC growth, immune cell evasion and angiogenesis. This is followed by a discussion of recent progress in the field in understanding the mechanistic crosstalk between HSC and HCC, and the pathways that are potentially amenable to therapeutic intervention. Furthermore, we summarise the exciting recent developments in strategies to target HSC specifically, and novel techniques to deliver pharmaceutical agents directly to HSC, potentially allowing tailored, cell-specific therapy for HCC.

Priming cancer cells for drug resistance: role of the fibroblast niche

Conventional and targeted chemotherapies remain integral strategies to treat solid tumors. Despite the large number of anti-cancer drugs available, chemotherapy does not completely eradicate disease. Disease recurrence and the growth of drug resistant tumors remain significant problems in anti-cancer treatment. To develop more effective treatment strategies, it is important to understand the underlying cellular and molecular mechanisms of drug resistance. It is generally accepted that cancer cells do not function alone, but evolve through interactions with the surrounding tumor microenvironment. As key cellular components of the tumor microenvironment, fibroblasts regulate the growth and progression of many solid tumors. Emerging studies demonstrate that fibroblasts secrete a multitude of factors that enable cancer cells to become drug resistant. This review will explore how fibroblast secretion of soluble factors act on cancer cells to enhance cancer cell survival and cancer stem cell renewal, contributing to the development of drug resistant cancer.

[Molecular mechanisms of progression in human hepatocarcinogenesis]

Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors worldwide with poor prognosis. Based on high-throughput screening technology, we and others have identified factors and pathways that are pivotal for tumor progression including transcription factors and microtubule-interacting proteins. In addition, aberrant activation of the IGF signalling pathway is frequently observed in HCCs which is predominantly based on high level expression of its ligand IGF-II. Because protumorigenic effects of IGF-II such as proliferation, anti-apoptosis, and migration are transmitted through its receptor IGF-1R, selective inhibition of this tyrosine kinase by small molecule compounds might reduce IGF-II-driven tumor growth. Indeed, administration of IGF-1R-selective inhibitors reduces IGF-II-induced effects and was associated with a significant reduction of tumor growth in a xenograft transplantation model. In conclusion, the IGF-II/IGF-1R signalling pathway is critically involved in the regulation of tumor growth and tumor cell dissemination, representing a promising therapeutic target structure in the treatment of HCC.

Gene expression profiles during activation of cultured rat hepatic stellate cells by tumoral hepatocytes and fetal bovine serum

PURPOSE

Hepatic stellate cells (HSCs) transdifferentiate to become extracellular matrix-producing myofibroblasts during liver injury. Myofibroblasts can also promote invasion and metastasis of hepatocellular carcinoma (HCC). In this study, we determined gene expression changes in two different models of HSC activation, induction-activated HSCs (iHSCs) and culture-activated HSCs (cHSCs).

METHODS

Hepatic stellate cells were isolated by density centrifugation and exposed to conditioned medium (CM) from the rat HCC cell line C5F, and fetal bovine serum (FBS). Expression of 27,100 genes in quiescent HSCs, cHSCs and iHSCs was analyzed by microarray and was confirmed on a subset of genes by real-time RT-PCR and Western blot.

RESULTS

One thousand nine hundred sixty-seven genes were differentially expressed in cHSCs and iHSCs, including genes that encode proinflammatory factors, adhesion molecules, cell surface receptors, signaling transduction and immune factors such as Il1a, Vcam1, Ccl6, Ilr7, PRAP, osteopontin, Gp39, Raf1, Rac2, Adam17, Wnt6, MMP-9, and Cfd. C5F-CM-induced activation only partially reproduced the gene expression changes observed during FBS culture activation. iHSCs showed specific gene expression, suggesting that HCC cells can specifically induce HSC activation.

CONCLUSIONS

Induction- activated HSCs' gene expression patterns were partially similar to and different from that of cHSCs. iHSCs might play an important role in invasion and metastasis of HCC. This study provided theoretical foundations for investigating the biology of HSCs in HCC.

[Molecular pathogenesis of hepatocellular carcinoma: new therapeutic approaches and predictive pathology]

Hepatocellular carcinoma is one of the most prevalent malignancies worldwide and its incidence is increasing. Multimodal strategies directed towards this carcinoma include primary (e.g. immunisation) and secondary (e.g. antiviral therapy) prevention, surgical approaches, novel specific systemic therapies (targeted therapy), and the treatment of comorbidity (cirrhosis). New molecular approaches are currently under development. These tackle several specific targets, with pathology being challenged in many aspects: experimental evaluation, the development of valid tumor-relevant diagnostic tests as well as morphological evaluation in the context of clinical studies, and finally in routine diagnosis.

Tumors Initiated by Constitutive Cdk2 Activation Exhibit Transforming Growth Factor β Resistance and Acquire Paracrine Mitogenic Stimulation during Progression

Cyclin D1/cyclin-dependent kinase 2 (Cdk2) complexes are present at high frequency in human breast cancer cell lines, but the significance of this observation is unknown. This report shows that expression of a cyclin D1-Cdk2 fusion protein under the control of the mouse mammary tumor virus (MMTV) promoter results in mammary gland hyperplasia and fibrosis, and mammary tumors. Cell lines isolated from MMTV-cyclin D1-Cdk2 (MMTV-D1K2) tumors exhibit Rb and p130 hyperphosphorylation and up-regulation of the protein products of E2F-dependent genes. These results suggest that cyclin D1/Cdk2 complexes may mediate some of the transforming effects that result from cyclin D1 overexpression in human breast cancers. MMTV-D1K2 cancer cells express the hepatocyte growth factor (HGF) receptor, c-Met. MMTV-D1K2 cancer cells also secrete transforming growth factor beta (TGFbeta), but are relatively resistant to TGFbeta antiproliferative effects. Fibroblasts derived from MMTV-D1K2 tumors secrete factors that stimulate the proliferation of MMTV-D1K2 cancer cells, stimulate c-Met tyrosine phosphorylation, and stimulate the phosphorylation of the downstream signaling intermediates p70(s6k) and Akt on activating sites. Together, these results suggest that deregulation of the Cdk/Rb/E2F axis reprograms mammary epithelial cells to initiate a paracrine loop with tumor-associated fibroblasts involving TGFbeta and HGF, resulting in desmoplasia. The MMTV-D1K2 mice should provide a useful model system for the development of therapeutic approaches to block the stromal desmoplastic reaction that likely plays an important role in the progression of multiple types of human tumors.

HGF synthesis in human lung fibroblasts is regulated by oncostatin M

Oncostatin M (OSM) is a IL-6 family cytokine locally produced in acute lung injury. Its profibrotic properties suggest a role in lung wound repair. Hepatocyte growth factor (HGF), produced by fibroblasts, is involved in pulmonary epithelial repair. We investigated the role of OSM in HGF synthesis by human lung fibroblasts. We showed that OSM upregulated HGF mRNA in MRC5 cells and in human lung fibroblasts, whereas IL-6 and leukemia inhibitory factor did not. OSM induced HGF secretion to a similar extent as IL-1beta in both a time- and dose-dependent manner. HGF was released in its cleaved mature form, and its secretion was completely inhibited in the presence of cycloheximide, indicating a de novo protein synthesis. OSM in combination with prostaglandin E(2), a powerful HGF inductor, led to an additive effect. OSM and indomethacin in combination further increased HGF secretion. This could be explained, at least in part, by a moderate upregulation of specific OSM receptor beta mRNA expression through cyclooxygenase inhibition. These results demonstrate that OSM-induced HGF synthesis did not involve a PGE(2) pathway. OSM-induced HGF secretion was inhibited by PD-98059 (a specific pharmacological inhibitor of ERK1/2), SB-203580 (a p38 MAPK inhibitor), and SP-600125 (a JNK inhibitor) by 70, 82, and 100%, respectively, whereas basal HGF secretion was only inhibited by SP-600125 by 30%. Our results demonstrate a specific upregulation of HGF synthesis by OSM, most likely through a MAPK pathway, and support the suggestion that OSM may participate in lung repair through HGF production.