Wnt-Pathway Activation in Two Molecular Classes of Hepatocellular Carcinoma and Experimental Modulation by Sorafenib (original) (raw)

Canonical Wnt signaling is antagonized by noncanonical Wnt5a in hepatocellular carcinoma cells

Molecular Cancer, 2009

Background: -catenin mutations that constitutively activate the canonical Wnt signaling have been observed in a subset of hepatocellular carcinomas (HCCs). These mutations are associated with chromosomal stability, low histological grade, low tumor invasion and better patient survival. We hypothesized that canonical Wnt signaling is selectively activated in well-differentiated, but repressed in poorly differentiated HCCs. To this aim, we characterized differentiation status of HCC cell lines and compared their expression status of Wnt pathway genes, and explored their activity of canonical Wnt signaling.

WNT/β-catenin pathway activation in hepatocellular carcinoma: a clinical perspective

Gastrointestinal Cancer: Targets and Therapy, 2014

Hepatocellular carcinoma (HCC) is a significant global health concern which requires multidisciplinary approaches in its management. However, apart from surgical resection of the tumor, molecularly targeted therapeutics remains limited to sorafenib. New targets and drugs are urgently needed to broaden the currently limited treatment options for HCC to allow more efficacious clinical interventions and ultimately to improve the overall survival of HCC patients. The WNT/β-catenin pathway controls multiple biological functions throughout embryonic development and adult homeostasis; its dysregulation underlies a wide range of pathologies including cancer. In particular, many lines of evidence suggest that hyperactivation of this pathway is associated with the initiation and development of HCC. The critical role of the WNT to WNT/β-catenin pathway in HCC lends itself to rationally designed approaches to intervene with various aberrant loci along its signaling cascade to achieve therapeutic effects in HCC. Here, we review the current state of knowledge on WNT/β-catenin pathway deregulation in HCC, and how this pathway may be exploited for therapeutic interventions.

Comparative analysis of Wnt signaling-related proteins in normal, benign, malignant and metastasised human liver tumors

2020

Background and AimsLiver cancer comprises of benign or malignant tumors including hepatocellular carcinoma (HCC), cholangiocarcinoma (CC), hepatoblastoma (HB), and other rarer tumor types. There is evidence of aberrant Wnt signaling during initiation and progression of HCC, CC and HB.MethodsWe investigated the expression of Wnt/β-catenin transcription related proteins, Cyclin D1, c-Myc, Fra-1 and Pygo-1, in human liver tumors by using an unbiased, quantitative immunohistochemical (qIHC) approach.ResultsSemi-automated, unbiased quantitation of individual proteins revealed reduced expression of Cyclin D1 and Pygo-1 in CC (P < 0.0001 and P < 0.01, respectively) and HB (P < 0.05 and P < 0.01, respectively) compared to normal liver (NL). Receiver operating characteristic curves showed Cyclin D1 as a putative marker for CC (AUC > 0.8) that discriminates CC from both NL and HCC (P ≤ 0.0001), and Pygo-1 (AUC > 0.7) as a marker for both CC and HCC (P < 0.01) compared to ...

Blockade of Wnt-1 signaling leads to anti-tumor effects in hepatocellular carcinoma cells

Molecular Cancer, 2009

Background: Hepatocellular carcinoma (HCC) is an aggressive cancer, and is the third leading cause of cancer death worldwide. Standard therapy is ineffective partly because HCC is intrinsically resistant to conventional chemotherapy. Its poor prognosis and limited treatment options make it critical to develop novel and selective chemotherapeutic agents. Since the Wnt/β-catenin pathway is essential in HCC carcinogenesis, we studied the inhibition of Wnt-1-mediated signaling as a potential molecular target in HCC.

Wnt signaling and hepatocarcinogenesis: The hepatoblastoma model

The International Journal of Biochemistry & Cell Biology, 2011

The β-catenin mutation is frequently observed in hepatoblastoma (HB), but the underlying mechanism by which Wnt/β-catenin signaling induces HB tumor formation is unknown. Here we show that expression of growth regulation by estrogen in breast cancer 1 (GREB1) depends on Wnt/β-catenin signaling in HB patients. GREB1 is localized to the nucleus where it binds Smad2/3 in a competitive manner with p300 and inhibits TGFβ signaling, thereby promoting HepG2 HB cell proliferation. Forced expression of β-catenin, YAP, and c-Met induces HB-like mouse liver tumor (BYM mice), with an increase in GREB1 expression and HB markers. Depletion of GREB1 strongly suppresses marker gene expression and HB-like liver tumorigenesis, and instead enhances TGFβ signaling in BYM mice. Furthermore, antisense oligonucleotides for GREB1 suppress the formation of HepG2 cell-induced tumors and HB-like tumors in vivo. We propose that GREB1 is a target molecule of Wnt/β-catenin signaling and required for HB progression.

Blockade of Wnt Signaling Inhibits Angiogenesis and Tumor Growth in Hepatocellular Carcinoma

Cancer Research, 2009

Aberrant activation of Wnt signaling plays an important role in hepatocarcinogenesis. In addition to direct effects on tumor cells, Wnt signaling might be involved in the organization of tumor microenvironment. In this study, we have explored whether Wnt signaling blockade by exogenous expression of Wnt antagonists could inhibit tumor angiogenesis and control tumor growth. Human Wnt inhibitory factor 1 (WIF1) and secreted frizzled-related protein 1 (sFRP1) were each fused with Fc fragment of human IgG1 to construct fusion proteins WIF1-Fc and sFRP1-Fc. The recombinant adenoviral vectors carrying WIF1-Fc and sFRP1-Fc driven by cytomegalovirus promoter were constructed. Ad-WIF1-Fc or Ad-sFRP1-Fc induced the expression and correct conformation of WIF1-Fc and sFRP1-Fc fusion proteins. These molecules caused down-regulation of E2F1, cyclin D1, and c-myc and promoted cell apoptosis in hepatocellular carcinoma cells. Treatment of established hepatocellular carcinoma tumors with Ad-WIF1-Fc ...

Blocking Wnt Secretion Reduces Growth of Hepatocellular Carcinoma Cell Lines Mostly Independent of β-Catenin Signaling

Neoplasia, 2016

Aberrant activation of Wnt/β-catenin signaling plays a key role in the onset and development of hepatocellular carcinomas (HCC), with about half of them acquiring mutations in either CTNNB1 or AXIN1. However, it remains unclear whether these mutations impose sufficient β-catenin signaling or require upstream Wnt ligand activation for sustaining optimal growth, as previously suggested for colorectal cancers. Using a panel of nine HCC cell lines, we show that siRNA-mediated knockdown of β-catenin impairs growth of all these lines. Blocking Wnt secretion, by either treatment with the IWP12 porcupine inhibitor or knockdown of WLS, reduces growth of most of the lines. Unexpectedly, interfering with Wnt secretion does not clearly affect the level of β-catenin signaling in the majority of lines, suggesting that other mechanisms underlie the growth-suppressive effect. However, IWP12 treatment did not induce autophagy or endoplasmic reticulum (ER) stress, which may have resulted from the accumulation of Wnt ligands within the ER. Similar results were observed for colorectal cancer cell lines used for comparison in various assays. These results suggest that most colorectal and liver cancers with mutations in components of the β-catenin degradation complex do not strongly rely on extracellular Wnt ligand exposure to support optimal growth. In addition, our results also suggest that blocking Wnt secretion may aid in tumor suppression through alternative routes currently unappreciated.

Atypical regulators of Wnt/β-catenin signaling as potential therapeutic targets in Hepatocellular Carcinoma

Experimental biology and medicine (Maywood, N.J.), 2017

Hepatocellular carcinoma is one of the most common causes of cancer-related death worldwide. Hepatocellular carcinoma development depends on the inhibition and activation of multiple vital pathways, including the Wnt signaling pathway. The Wnt/β-catenin pathway lies at the center of various signaling pathways that regulate embryonic development, tissue homeostasis and cancers. Activation of the Wnt/β-catenin pathway has been observed frequently in hepatocellular carcinoma. However, activating mutations in β-catenin, Axin and Adenomatous Polyposis Coli only contribute to a portion of the Wnt signaling hyper-activation observed in hepatocellular carcinoma. Therefore, besides mutations in the canonical Wnt components, there must be additional atypical regulation or regulators during Wnt signaling activation that promote liver carcinogenesis. In this mini-review, we have tried to summarize some of these well-established factors and to highlight some recently identified novel factors in ...

Targeting Wnt/β-catenin pathway in hepatocellular carcinoma treatment

World journal of gastroenterology, 2016

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death worldwide. Liver cancer is generally related to hepatitis B or C infection and cirrhosis. Usually, patients with HCC are asymptomatic and are diagnosed at late stages when surgical treatment is no longer suitable. Limited treatment options for patients with advanced HCC are a major concern. Therefore, there is an urge for finding novel therapies to treat HCC. Liver cancer is highly heterogeneous and involved deregulation of several signaling pathways. Wnt/β-catenin pathway is frequently upregulated in HCC and it is implicated in maintenance of tumor initiating cells, drug resistance, tumor progression, and metastasis. A great effort in developing selective drugs to target components of the β-catenin pathway with anticancer activity is underway but only a few of them have reached phase I clinical trials. We aim to review the role of β-catenin pathway on hepatocarcinogenesis and liver cancer stem c...