Subtypes Of Hepatoblastoma Research Articles

Abstract 1100: Fascin-1 inhibitor decreases hepatoblastoma cells tumorigenicity via YAP 1

Abstract Introduction: Hepatoblastoma (HB) is a liver tumor that arises in children. It's a sporadic malignancy that is often overly aggressive. The current treatment consists of chemotherapy. However, chemotherapy in young patients has disastrous and long-term side effects such as ototoxicity, cardiomyopathy, and infertility. Thus, alternative strategies are needed. One hint is to target the most common mutations in HB. It has been demonstrated that 90% of HB tumors are mutated for the Wnt pathway effector ß-catenin. This mutation leads to an aberrant constitutive activation of Wnt/ß-catenin signaling. Here, we investigate one of ß-catenin transcriptional targets, Fascin-1 that is found up-regulated in many tumors. Fascin1 affects actin organization into bundles, and this leads to cell migration and invasion. Whereas Fascin-1 is absent from normal hepatocytes, we found its expression associated to the poor prognosis C2 subtype of HB. In both human and murine HB samples, Fascin-1 is associated to undifferentiated tumor cells. We further demonstrated that Fascin-1 expression modulates tumor hepatocyte differentiation status through gene expression. In this study, we investigate how Fascin-1 can regulate tumor cell plasticity and whether Fascin-1 is a druggable target in HB tumors. Methods: We use two classical HB model cells Huh6 and HepG2 and 3 Patient-Derived-Xenograft cell lines. We explore the effect of Fascin-1 actin-bundling activity impairment by using inhibitors, on invasion and migration using Trans-well and wound-healing assays. We follow proliferation and cell death by Flow cytometry and investigate gene expression by PCR and reporter assay. We investigate Fascin modulation of the kinome with PamGene technology. Results: We show that the inhibition of Fascin actin-binding activity decreases cell invasion and migration as well as proliferation. We show an increase of cell death in Huh6/HepG2 cells but not in the PDX models. A cell cycle arrest is induced, and the cells become senescent. Differentiation genes are overexpressed and EMT genes are repressed. Yap expression is downregulated; Yap promoter activity is downregulated, and Yap is found translocated into the cytoplasm upon Fascin-1 inhibition. These data suggest that Fascin inhibition decreases tumors cell invasion, induces cell senescence, and favors a switch towards a differentiated and these effects on the cells are mediated via the Hippo pathway. The kinome is also modulated. Conclusion: Fascin-1 is an interesting target in hepatoblastoma, commercialized phase-2 drugs are available, and this study will confirm the potential use of those drugs in HB treatment and elucidate by which mechanism Fascin-1 inhibition impacts tumors. Citation Format: Lydia DIF, Amandine Martin, Sara Basbous, Gregoire Manaud, Violaine Moreau. Fascin-1 inhibitor decreases hepatoblastoma cells tumorigenicity via YAP 1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1100.

Single-cell transcriptomics uncovers cellular architecture and developmental trajectories in hepatoblastoma.

Hepatoblastoma (HB) is the predominant type of childhood liver cancer. Treatment options for the clinically advanced HB remain limited. We aimed to dissect the cellular and molecular basis underlying HB oncogenesis and heterogeneity at the single-cell level, which could facilitate a better understanding of HB at both the biological and clinical levels. Single-cell transcriptome profiling of tumor and paired distal liver tissue samples from five patients with HB was performed. Deconvolution analysis was used for integrating the single-cell transcriptomic profiles with the bulk transcriptomes of our HB cohort of post-neoadjuvant chemotherapy tumor samples. A single-cell transcriptomic landscape of early human liver parenchymal development was established for exploring the cellular root and hierarchy of HB oncogenesis. As a result, seven distinct tumor cell subpopulations were annotated, and an effective HB subtyping method was established based on their compositions. A HB tumor cell hierarchy was further revealed to not only fit with the classical cancer stem cell (CSC) model but also mirror the early human liver parenchymal development. Moreover, FACT inhibition, which could disrupt the oncogenic positive feedback loop between MYC and SSRP1 in HB, was identified as a promising epigenetic-targeted therapeutic strategy against the CSC-like HB1-Pro-like1 subpopulation and its related high-risk "Pro-like1" subtype of HB. Our findings illustrate the cellular architecture and developmental trajectories of HB via integrative bulk and single-cell transcriptome analyses, thus establishing a resourceful framework for the development of targeted diagnostics and therapeutics in the future.

Copy Number Alterations in Hepatoblastoma: Literature Review and a Brazilian Cohort Analysis Highlight New Biological Pathways

Hepatoblastoma (HB) is a rare embryonal tumor, although it is the most common pediatric liver cancer. The aim of this study was to provide an accurate cytogenomic profile of this type of cancer, for which information in cancer databases is lacking. We performed an extensive literature review of cytogenetic studies on HBs disclosing that the most frequent copy number alterations (CNAs) are gains of 1q, 2/2q, 8/8q, and 20; and losses at 1p and 4q. Furthermore, the CNA profile of a Brazilian cohort of 26 HBs was obtained by array-CGH; the most recurrent CNAs were the same as shown in the literature review. Importantly, HBs from female patients, high-risk stratification tumors, tumors who developed in older patients (> 3 years at diagnosis) or from patients with metastasis and/or deceased carried a higher diversity of chromosomal alterations, specifically chromosomal losses at 1p, 4, 11q and 18q. In addition, we distinguished three major CNA profiles: no detectable CNA, few CNAs and tumors with complex genomes. Tumors with simpler genomes exhibited a significant association with the epithelial fetal subtype of HBs; in contrast, the complex genome group included three cases with epithelial embryonal histology, as well as the only HB with HCC features. A significant association of complex HB genomes was observed with older patients who developed high-risk tumors, metastasis, and deceased. Moreover, two patients with HBs exhibiting complex genomes were born with congenital anomalies. Together, these findings suggest that a high load of CNAs, mainly chromosomal losses, particularly losses at 1p and 18, increases the tendency to HB aggressiveness. Additionally, we identified six hot-spot chromosome regions most frequently affected in the entire group: 1q31.3q42.3, 2q23.3q37.3, and 20p13p11.1 gains, besides a 5,3 Mb amplification at 2q24.2q24.3, and losses at 1p36.33p35.1, 4p14 and 4q21.22q25. An in-silico analysis using the genes mapped to these six regions revealed several enriched biological pathways such as ERK Signaling, MicroRNAs in Cancer, and the PI3K-Akt Signaling, in addition to the WNT Signaling pathway; further investigation is required to evaluate if disturbances of these pathways can contribute to HB tumorigenesis. The analyzed gene set was found to be associated with neoplasms, abnormalities of metabolism/homeostasis and liver morphology, as well as abnormal embryonic development and cytokine secretion. In conclusion, we have provided a comprehensive characterization of the spectrum of chromosomal alterations reported in HBs and identified specific genomic regions recurrently altered in a Brazilian HB group, pointing to new biological pathways, and relevant clinical associations.

Hepatoblastoma: glutamine depletion hinders cell viability in the embryonal subtype but high GLUL expression is associated with better overall survival

PurposeGlutamine plays an important role in cell viability and growth of various tumors. For the fetal subtype of hepatoblastoma, growth inhibition through glutamine depletion was shown. We studied glutamine depletion in embryonal cell lines of hepatoblastoma carrying different mutations. Since asparagine synthetase was identified as a prognostic factor and potential therapeutic target in adult hepatocellular carcinoma, we investigated the expression of its gene ASNS and of the gene GLUL, encoding for glutamine synthetase, in hepatoblastoma specimens and cell lines and investigated the correlation with overall survival.MethodsWe correlated GLUL and ASNS expression with overall survival using publicly available microarray and clinical data. We examined GLUL and ASNS expression by RT-qPCR and by Western blot analysis in the embryonal cell lines Huh-6 and HepT1, and in five hepatoblastoma specimens. In the same cell lines, we investigated the effects of glutamine depletion. Hepatoblastoma biopsies were examined for histology and CTNNB1 mutations.ResultsHigh GLUL expression was associated with a higher median survival time. Independent of mutations and histology, hepatoblastoma samples showed strong GLUL expression and glutamine synthesis. Glutamine depletion resulted in the inhibition of proliferation and of cell viability in both embryonal hepatoblastoma cell lines. ASNS expression did not correlate with overall survival.ConclusionGrowth inhibition resulting from glutamine depletion, as described for the hepatoblastoma fetal subtype, is also detected in established embryonal hepatoblastoma cell lines carrying different mutations. At variance with adult hepatocellular carcinoma, in hepatoblastoma asparagine synthetase has no prognostic significance.

Characterization of hsa_circ_0000594 as a new biomarker and therapeutic target for hepatoblastoma.

Various studies have shown that aberrant expression of circular RNAs (circRNAs) has a pivotal role in multifarious cancers. However, the role of circRNAs in hepatoblastoma (HB) is not clearly understood. In the present study, we attempted to explore the underlying mechanism of hsa_cric_0000594 in HB along with its clinical importance. In our research, the expression pattern of hsa_circ_0000594 in HB tissues and matched normal liver tissues was determined by in situ hybridization and RT-qPCR. Proliferation, viability, migration, and apoptosis of HB cell lines were detected via Cell Counting Kit-8 (CCK-8), colony formation, transwell, and flow cytometry assays. The interaction of hsa_circ_0000594 with miR-217 was investigated by Dual-Luciferase reporter assay. Expression levels of hsa_circ_0000594 were significantly upregulated in HB tissues compared with those in paired normal liver tissues and showed a clear association with the subtype of HB. The knockdown of hsa_circ_0000594 inhibited the malignant phenotype of HB. Bioinformatics analysis suggests that sirtuin 1 (SIRT1) may serve as a target gene of miR-217. Mechanically, hsa_circ_0000594 was identified to have a critical role in HB development through the hsa_circ_0000594/mir-217/SIRT1 regulatory axis, which might become a novel diagnostic marker and potential therapeutic target in HB.

Mutant CTNNB1 and histological heterogeneity define metabolic subtypes of hepatoblastoma

Hepatoblastoma is the most common malignant pediatric liver cancer. Histological evaluation of tumor biopsies is used to distinguish among the different subtypes of hepatoblastoma, with fetal and embryonal representing the two main epithelial components. With frequent CTNNB1 mutations, hepatoblastoma is a Wnt/β‐catenin‐driven malignancy. Considering that Wnt activation has been associated with tumor metabolic reprogramming, we characterized the metabolic profile of cells from hepatoblastoma and compared it to cells from hepatocellular carcinoma. First, we demonstrated that glucose transporter GLUT3 is a direct TCF4/β‐catenin target gene. RNA sequencing enabled to identify molecular and metabolic features specific to hepatoblastoma and revealed that several glycolytic enzymes are overexpressed in embryonal‐like compared to fetal‐like tumor cells. This led us to implement successfully three biomarkers to distinguish embryonal from fetal components by immunohistochemistry from a large panel of human hepatoblastoma samples. Functional analyses demonstrated that embryonal‐like hepatoblastoma cells are highly glycolytic and sensitive to hexokinase‐1 silencing. Altogether, our findings reveal a new, metabolic classification of human hepatoblastoma, with potential future implications for patients’ diagnosis and treatment.

Hepatocellular malignant neoplasm, NOS: a clinicopathological study of 11 cases from a single institution.

The primary aim of this study is to characterize hepatocellular malignant neoplasm, NOS (HEMNOS), a new provisional entity describing a subset of paediatric hepatocellular tumours, which have histological features of neither typical hepatoblastoma (HB) nor hepatocellular carcinoma (HCC). The clinicopathological features of 11 patients with HEMNOS were analysed retrospectively. The median age and serum alpha-fetoprotein level at diagnosis was 7years and 182000ng/ml, respectively. Ten patients presented with pretreatment extent of disease (PRETEXT) stages III/IV multifocal tumours, eight with major vascular involvement, three with lung metastases and three with extrahepatic extension. The original pathology diagnoses were: HB in seven patients, HCC in two and HEMNOS in two. Our pathology review of pre-chemotherapy specimens showed that six tumours had equivocal/overlapping histological features of HB and HCC, four had predominant HB histology along with focal HCC-like histology and one had HB histology. Seven of nine post-chemotherapy resection specimens showed predominant HCC-like histology. Beta-catenin, glypican 3 and spalt-like transcription factor 4 immunostaining showed that all the tumours had a mixed HB/HCC immunophenotype. Telomerase reverse transcriptase immunostaining showed nuclear staining in nine of the 11 tumours. All patients received chemotherapy and achieved gross total primary tumour resection. Nine of the 11 patients were treated with established HB chemotherapy regimens. After a median follow-up of 6.1years (range: 1.2-11.8years), all patients were in remission. HEMNOS is a subtype of HB with focal HCC-like histology, a high-risk clinical profile but favourable outcome following chemotherapy and complete tumour resection.

Novel Advances in Understanding of Molecular Pathogenesis of Hepatoblastoma: A Wnt/β-Catenin Perspective.

Hepatoblastoma is the most common pediatric liver malignancy, typically striking children within the first 3 years of their young lives. While advances in chemotherapy and newer surgical techniques have improved survival in patients with localized disease, unfortunately, for the 25% of patients with metastasis, the overall survival remains poor. These tumors, which are thought to arise from hepatic progenitors or hepatoblasts, hence the name hepatoblastoma, can be categorized by histological subtyping based on their level of cell differentiation. Genomic and histological analysis of human tumor samples has shown exon-3 deletions or missense mutations in gene coding for β-catenin, a downstream effector of the Wnt signaling pathway, in up to 90% of hepatoblastoma cases. The current article will review key aberrations in molecular pathways that are implicated in various subtypes of hepatoblastoma with an emphasis on Wnt signaling. It will also discuss cooperation among components of pathways such as β-catenin and Yes-associated protein in cancer development. Understanding the complex network of molecular signaling in oncogenesis will undoubtedly aid in the discovery of new therapeutics to help combat hepatoblastoma.

High tricellulin expression is associated with better survival in human hepatoblastoma.

The more differentiated fetal component of hepatoblastoma (HB) is characterized by increased expression of tight junction (TJ) proteins claudin-1 and -2 when compared with embryonal component. Expression patterns of the recently identified TJ protein tricellulin and the epigenetic regulator enzyme EZH2 were investigated in epithelial subtypes of HB and related to survival. Twenty-one cases of epithelial HBs subtyped as pure fetal (n=12) and embryonal/fetal (n=9), along with 16 non-tumorous samples from surrounding liver, were analysed by immunohistochemistry for tricellulin, β-catenin and EZH2 expression. No significant differences were revealed in overall survival between fetal and embryonal/fetal types of HBs. The fetal component, however, showed considerably increased tricellulin expression while the embryonal component displayed significantly increased nuclear EZH2 positivity, in comparison to other epithelial subtypes and non-tumorous surrounding hepatocytes. Strong nuclear β-catenin staining was notably more frequent in embryonal than in fetal types. High tricellulin expression was associated with significantly increased overall survival (P=0.03), while elevated EZH2 expression was linked to the presence of distant metastases (P=0.013). Our data indicate that patients with treated HBs showing high expression of tricellulin have significantly better overall survival, independent of histological subtype. Increased nuclear expression of EZH2 was associated with the presence of distant metastases.

MicroRNA expression might predict prognosis of epithelial hepatoblastoma

Hepatoblastoma (HB) is the most common primary liver cancer in childhood. The fetal and mixed embryonal/fetal epithelial subtypes of HB differ not only in grade of differentiation but probably also in prognosis. We aimed to determine microRNA (miRNA) expression patterns of the main subtypes of epithelial HBs to reveal differences and relate them to survival. We studied 20 cases of epithelial HB, subtyped as pure fetal (n = 12) or embryonal/fetal (n = 8). Tissues were sampled according to subtype to arrive at 15 purely fetal and eight purely embryonal samples (n = 8) and 15 samples of non-tumorous surrounding liver (SL). Relative expression of miR-17-5p, miR-18a, miR-21, miR-34a, miR-96, miR-122, miR-181a, miR-195, miR-210, miR-214, miR-221, miR-222, miR-223, and miR-224 was determined by TaqMan MicroRNA Assays applying miR-140 as reference. A higher level of miR-18a (p < 0.01) was found in embryonal samples than in fetal samples. Lower miR-17-5p, miR-195, miR-210, miR-214, and higher miR-221 levels were detected in fetal samples (p < 0.02) in comparison with SL samples, whereas a lower miR-122 level was observed in embryonal samples (p < 0.003). Histological subtype did not correlate with survival; however, high miR-21, low miR-222, and low miR-224 levels proved to be independently prognostic for HB with significantly increased overall survival (p < 0.03). The fetal and embryonal components of epithelial HB, as well as SL, revealed different miRNA expression patterns. Furthermore, miR-21, miR-222, and miR-224 levels predict overall survival of HB patients regardless of epithelial subtype.

Cytogenetics of hepatoblastoma

The cytogenetics of hepatoblastoma demonstrate recurring events which include whole chromosome trisomies, most commonly trisomy of chromosome 2, 8, or 10. In addition, unbalanced translocations involving a breakpoint on the proximal short arm of chromosome 1 are observed which result in a duplication of the long arm of chromosome 1q. The most commonly involved reciprocal chromosomal arm is 4q, although the reciprocal chromosome is highly variable and always results in a loss of chromosomal material. The full significance of these chromosomal changes has yet to be confirmed in large studies, however a suggestion of an association of duplication of regions of 2q with a poor prognosis. A rare sub-type of hepatoblastoma, known as the small cell undifferentiated variant, is associated with deletion or translocation of 22q, the locus of the rhabdoid tumor gene, SMARCB1.

The emerging family of hepatoblastoma tumours: From ontogenesis to oncogenesis

The identification of distinct types and subtypes of hepatoblastoma has led to a successful classification of these lesions. In recent years, and particularly within large tumour trials, the spectrum of paediatric epithelial liver tumours has increased. This, together with the need for defining clinically relevant risk groups, will require a new approach to defining and classifying these cancers. Furthermore, an impressive amount of molecular biological information on liver ontogenesis and growth regulation of hepatic tumours has recently accumulated, which will allow the development of a comprehensive classification system with particular emphasis on prognostics. In this review, novel findings relating to these issues are discussed.

Comparative genomic hybridization analysis of hepatoblastoma reveals high frequency of X-chromosome gains and similarities between epithelial and stromal components

Hepatoblastoma (HB) is the most common liver tumor in childhood and differs in its environmental risk factors and genetic background from hepatocellular carcinoma. HB is associated with inherited conditions such as familial adenomatous polyposis and Beckwith-Wiedemann syndrome, suggesting the importance of genetic abnormalities in the pathogenesis and progression of this disease. It has a very polymorphous morphology. A diverse range of cytogenetic alterations has been reported to date, the most frequent being trisomy 2 and trisomy 20. Thirty-five HB specimens from 31 patients (22 purely epithelial, 4 purely mesenchymal, 9 mixed) were examined by comparative genomic hybridization (CGH), a technique that enables us to screen the entire tumor genome for genetic losses and gains. Our aims were as follows: (1) to characterize chromosome abnormalities that appear in this tumor and (2) to identify possible differences between different histologic subtypes of HB. We found significant gains of genetic material, with very little difference in the number and type of alterations between the different histologic components of HB. The most frequent alterations were gains of Xp (15 cases, 43%) and Xq (21 cases, 60%). This finding was also confirmed by fluorescent in situ hybridization performed on nuclei extracted from 6 specimens. Other common alterations were 1p−, 2q+, 2q−, 4q−, and 4q+. We found no difference between different histologic subtypes, a finding that may be in agreement with the hypothesis of a common clonal origin for the different components. An hitherto-unreported high frequency of X chromosome gains may support the assumption that X-linked genes are involved in the development of this neoplasm.

Hepatoblastoma: A Rare Pediatric Neoplasm

The differential diagnosis of an abdominal mass in an infant or young child includes hepatoblastoma. This rare embryonal neoplasm of the liver is linked to several congenital abnormalities and may be associated with maternal occupational exposure to metal fumes, petroleum products, or paints. Alpha-fetoprotein is a useful tumor marker that may also be elevated with hepatocellular carcinoma. The relatively better prognosis of hepatoblastoma, if completely resected, mandates its differentiation from hepatoma. The fetal subtype of hepatoblastoma seems to represent a "favorable" histology pattern.