Epigenetics and genetics of hepatoblastoma: Linkage and treatment

Adult Hepatoblastoma and Concomitant Hepatitis B Infection

We report a case of hepatoblastoma in a 26-year-old man with a background of type 2 diabetes mellitus and untreated hepatitis B, initially presenting with hematemesis and a recent diagnosis of hepatocellular carcinoma on computed tomography scan from a different hospital and recent referral to hospice. On presentation to our hospital, given atypical presentation for hepatocellular carcinoma, histological examination was made, revealing hepatoblastoma. Treatment included chemotherapy and management of hepatitis B, although complicated by chemotherapy-induced cytopenias and tumor progression, ultimately losing the patient to follow-up after 2 years.

From diagnosis to therapy: The critical role of lncRNAs in hepatoblastoma

According to findings, long non-coding RNAs (lncRNAs) serves an integral part in growth and development of a variety of human malignancies, including Hepatoblastoma (HB). HB is a rare kind of carcinoma of the liver that mostly affects kids and babies under the age of three. Its manifestations include digestive swelling, abdominal discomfort, and losing weight. This thorough investigation digs into the many roles that lncRNAs serve in HB, giving views into their varied activities as well as possible therapeutic consequences. The function of lncRNAs in HB cell proliferation, apoptosis, migratory and penetrating capacities, epithelial-mesenchymal transition, and therapy tolerance is discussed. Various lncRNA regulatory roles are investigated in depth, yielding information on their effect on essential cell processes such as angiogenesis, apoptosis, immunity, and growth. Circulating lncRNAs are currently acknowledged as potential indications for the initial stages of identification of cancer, with the ability to diagnose as well as forecast. In addition to their diagnostic utility, lncRNAs provide curative opportunities as locations and actors, contributing to the expanding landscape of cancer research. Several HB-linked lncRNAs have been demonstrated to exhibit abnormal expression and are involved in tumor-like characteristics via DNA, RNA, or protein binding or encoding short peptides. As a result, a better knowledge of lncRNA instability might bring fresh perspectives into HB etiology as well as innovative strategies for HB early diagnosis and therapy. We describe the abnormalities of lncRNA expression in HB and their tumor-suppressive or carcinogenic activities during HB carcinogenesis in this study. Furthermore, we explore lncRNAs' diagnostic and therapeutic possibilities in HB.

Strategies to enhance the response of liver cancer to pharmacological treatments

In contrast to other types of cancers, there is no available efficient pharmacological treatment to improve the outcomes of patients suffering from major primary liver cancers, i.e., hepatocellular carcinoma and cholangiocarcinoma. This dismal situation is partly due to the existence in these tumors of many different and synergistic mechanisms of resistance, accounting for the lack of response of these patients, not only to classical chemotherapy but also to more modern pharmacological agents based on the inhibition of tyrosine kinase receptors (TKIs) and the stimulation of the immune response against the tumor using immune checkpoint inhibitors (ICIs). This review summarizes the efforts to develop strategies to overcome this severe limitation, including searching for novel drugs derived from synthetic, semisynthetic, or natural products with vectorial properties against therapeutic targets to increase drug uptake or reduce drug export from cancer cells. Besides, immunotherapy is a promising line of research that is already starting to be implemented in clinical practice. Although less successful than in other cancers, the foreseen future for this strategy in treating liver cancers is considerable. Similarly, the pharmacological inhibition of epigenetic targets is highly promising. Many novel "epidrugs," able to act on "writer," "reader," and "eraser" epigenetic players, are currently being evaluated in preclinical and clinical studies. Finally, gene therapy is a broad field of research in the fight against liver cancer chemoresistance, based on the impressive advances recently achieved in gene manipulation. In sum, although the present is still dismal, there is reason for hope in the non-too-distant future.

Inhibition of Histone Deacetylase Activity Increases Cisplatin Efficacy to Eliminate Metastatic Cells in Pediatric Liver Cancers

The pediatric liver cancers, hepatoblastoma and hepatocellular carcinoma, are dangerous cancers which often spread to the lungs. Although treatments with cisplatin significantly improve outcomes, cisplatin may not eliminate metastasis-initiating cells. Our group has recently shown that the metastatic microenvironments of hepatoblastoma contain Cancer Associated Fibroblasts (CAFs) and neuron-like cells, which initiate cancer spread from liver to lungs. In this study, we found that these cells express high levels of HDAC1; therefore, we examined if histone deacetylase inhibition improves cisplatin anti-proliferative effects and reduces the formation of tumor clusters in pediatric liver cancer metastatic microenvironments.

METHODS

New cell lines were generated from primary hepatoblastoma liver tumors (hbl) and lung metastases (LM) of HBL patients. In addition, cell lines were generated from hepatocellular neoplasm, not otherwise specified (HCN-NOS) tumor samples, and hcc cell lines. Hbl, LM and hcc cells were treated with cisplatin, SAHA or in combination. The effect of these drugs on the number of cells, formation of tumor clusters and HDAC1-Sp5-p21 axis were examined.

RESULTS

Both HBL and HCC tissue specimens have increased HDAC1-Sp5 pathway activation, recapitulated in cell lines generated from the tumors. HDAC inhibition with vorinostat (SAHA) increases cisplatin efficacy to eliminate CAFs in hbl and in hcc cell lines. Although the neuron-like cells survive the combined treatments, proliferation was inhibited. Notably, combining SAHA with cisplatin overcame cisplatin resistance in an LM cell line from an aggressive case with multiple metastases. Underlying mechanisms of this enhanced inhibition include suppression of the HDAC1-Sp5 pathway and elevation of an inhibitor of proliferation p21. Similar findings were found with gemcitabine treatments suggesting that elimination of proliferative CAFs cells is a key event in the inhibition of mitotic microenvironment.

CONCLUSIONS

Our studies demonstrate the synergistic benefits of HDAC inhibition and cisplatin to eliminate metastasis-initiating cells in pediatric liver cancers.

First Transcriptome Analysis of Hepatoblastoma in Brazil: Unraveling the Pivotal Role of Noncoding RNAs and Metabolic Pathways

Hepatoblastoma stands as the most prevalent liver cancer in the pediatric population. Characterized by a low mutational burden, chromosomal and epigenetic alterations are key drivers of its tumorigenesis. Transcriptome analysis is a powerful tool for unraveling the molecular intricacies of hepatoblastoma, shedding light on the effects of genetic and epigenetic changes on gene expression. In this study conducted in Brazilian patients, an in-depth whole transcriptome analysis was performed on 14 primary hepatoblastomas, compared to control liver tissues. The analysis unveiled 1,492 differentially expressed genes (1,031 upregulated and 461 downregulated), including 920 protein-coding genes (62%). Upregulated biological processes were linked to cell differentiation, signaling, morphogenesis, and development, involving known hepatoblastoma-associated genes (DLK1, MEG3, HDAC2, TET1, HMGA2, DKK1, DKK4), alongside with novel findings (GYNG4, CDH3, and TNFRSF19). Downregulated processes predominantly centered around oxidation and metabolism, affecting amines, nicotinamides, and lipids, featuring novel discoveries like the repression of SYT7, TTC36, THRSP, CCND1, GCK and CAMK2B. Two genes, which displayed a concordant pattern of DNA methylation alteration in their promoter regions and dysregulation in the transcriptome, were further validated by RT-qPCR: the upregulated TNFRSF19, a key gene in the embryonic development, and the repressed THRSP, connected to lipid metabolism. Furthermore, based on protein-protein interaction analysis, we identified genes holding central positions in the network, such as HDAC2, CCND1, GCK, and CAMK2B, among others, that emerged as prime candidates warranting functional validation in future studies. Notably, a significant dysregulation of non-coding RNAs (ncRNAs), predominantly upregulated transcripts, was observed, with 42% of the top 50 highly expressed genes being ncRNAs. An integrative miRNA-mRNA analysis revealed crucial biological processes associated with metabolism, oxidation reactions of lipids and carbohydrates, and methylation-dependent chromatin silencing. In particular, four upregulated miRNAs (miR-186, miR-214, miR-377, and miR-494) played a pivotal role in the network, potentially targeting multiple protein-coding transcripts, including CCND1 and CAMK2B. In summary, our transcriptome analysis highlighted disrupted embryonic development as well as metabolic pathways, particularly those involving lipids, emphasizing the emerging role of ncRNAs as epigenetic regulators in hepatoblastomas. These findings provide insights into the complexity of the hepatoblastoma transcriptome and identify potential targets for future therapeutic interventions.

Atrichia with papular lesions in a 1-year-old girl resulting from a new homozygous nonsense pathogenic variant in the hairless gene

Congenital atrichia is a rare disorder featuring the gradual shedding of hair at birth with near total hair loss in succeeding weeks or months. When accompanied by milia-like papules on the face or body it is called atrichia with papular lesions (APL), caused by germline pathogenic variants in the hairless (HR) gene and some somatic variants in HR are implicated in various malignancies. We report a case of a patient harbouring a germline homozygous nonsense variant in the HR gene presenting as APL with concomitant liver cancer.