/pdf/mitochondrial-dysfunction-and-induction-of-apoptosis-in-1nntg1in30.pdf

Mitochondrial Dysfunction and Induction of Apoptosis in Hepatocellular Carcinoma and Cholangiocarcinoma Cell Lines by Thymoquinone

/pdf/translational-pediatrics-reflections-for-the-21st-century-pjw14st8.pdf

Translational pediatrics: reflections for the 21st century and beyond

Thymoquinone (TQ), a plant-based bioactive constituent derived from the volatile oil of Nigella sativa, has been shown to possess some anti-neoplastic activities. The present study aimed to investigate the mitochondria and apoptosis observed when TQ is applied against hepatocellular carcinoma (HepG2) and cholangiocarcinoma (HuCCT1) cells, two of the most common primary tumors of the liver. All cell lines were treated with increasing concentrations of TQ for varying durations. The anti-proliferative effect of TQ was measured using the methoxyphenyl-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and resulted in dose- and time-dependent growth inhibition in both cell lines. Cell cycle, apoptosis, and assessment of mitochondria viability by morphology assessment and evaluation of the mitochondrial membrane potential were investigated. The present study confirms that TQ caused cell cycle arrest at different phases and induced apoptosis in both cell lines. A systematic review of rodent animal models was also carried out. Overall, our data seem to represent the most robust results, suggesting that TQ possesses promising therapeutic potential as an anti-tumor agent for the treatment of hepatocellular carcinoma and cholangiocarcinoma.

/pdf/mitochondrial-dysfunction-and-induction-of-apoptosis-in-35du7rl8.pdf

Hepatoblastoma (HB) is a rare primary malignancy but ranks as the most common type of malignant liver cancer that occurs in the first 5 years of neonates.1 A considerable proportion of patients with HB are faced with rapid progression characterised by multiple nodules at diagnosis, vascular invasion, chemoresistance and relapse.2 Although a combined therapy, including surgery and neoadjuvant chemotherapy, could significantly improve the overall survival rate of HB patients, approximately 30% of patients still experience relatively poor prognosis.3 Meanwhile, the early diagnosis for HB is intractable due to the ambiguity of the aetiology and the lack of serum biomarkers.4 Thus, it is still urgent to identify the underlying pathogenesis to achieve a better prognosis for HB patients. In this issue of Clinical and Translational Medicine, Cui et al. identified a novel regulatory cascade that may play a vital role in the progression of HB.5 In this work, they discussed the O-GlcNAcylation on a specific oncogene, namely La-related protein 1 (LAPR1), and elucidated the mechanism of the abnormal activation of LARP1 and the following tumour-promoting LARP1/DKK4/β-catenin cascade in HB carcinogenesis. LARP1 is a protein that belongs to the La superfamily and plays essential roles in various aspects of RNA metabolism, including mRNA translation, stability and splicing. The overexpression of LARP1 has been identified in multiple types of cancers with oncogenic functions (Table 1). The tumour-promoting effect of LARP1 is mediated by its regulatory function on mRNA translation. Specifically, LARP1 could bind to the 5′ untranslated region of target mRNAs, facilitating their translation by recruiting the translation initiation factor eukaryotic translation initiation factor 4E (eIF4E) to the m7G cap structure at the 5′ end of the mRNA.6 Other translation factors, such as poly(A)-binding protein (PABP) and eukaryotic translation initiation factor 4G (eIF4G), were also demonstrated to be associated with LARP1 in mRNA translation promotion.7 These interactions would significantly increase the stability and enrichment of mRNAs encoding for proteins involved in tumour cell proliferation and migration, such as c-Myc, cyclin D1 and Bcl-2.8, 9 Post-translational modifications of proteins, including phosphorylation, methylation and ubiquitination, are commonly observed and would play important roles in protein functioning and metabolism. Adding O-linked β-N-acetylglucosamine (O-GlcNAc) to the serine and threonine residues of proteins, known as O-GlcNAcylation, is a universal post-translational modification that could alter the functions and stabilities of proteins involved in various biological processes and diseases.18 Recent studies suggest that O-GlcNAcylation would play a significant role in the occurrence, growth, metastasis, drug resistance and cancer stem cell population maintenance of another liver cancer: hepatocellular carcinoma (HCC).19, 20 The principal oncogenic function of O-GlcNAcylation is revealed by the induction of proteins with abnormal behaviours or stimulus-responsiveness in HCC progression. In Cui's work, they proved that the Ser672 residue of LARP1 is O-GlcNAc-modified by O-GlcNAc transferase (OGT) in HB progression, which leads to LARP1 stabilisation to avoid ubiquitin-proteasome-mediated degradation. Moreover, several circRNAs have been demonstrated to play critical roles in the upregulation of LARP1.15, 21 The authors also revealed that the binding of circCLNS1A to LARP1 can protect LARP1 from ubiquitination and proteolysis by competing with the degradation mediator tripatite motif containing 25 (TRIM-25). These findings delineated the mechanism of the abnormal upregulation of LARP1 and provided potential strategies for targeting this oncogenic alteration. The Wnt/β-catenin signalling pathway is a well-known oncogenic pathway proven guilty of the malignancy and heterogeneity of numerous types of cancers. The core regulatory pattern of the canonical Wnt pathway is the binding of Wnt ligands with fizzed proteins (FZDs) as well as LRP5/6 downregulating the phosphorylation and degradation of β-catenin. As a result, accumulated active β-catenin triggers the nuclear translocation and activates the T-cell factor/lymphoid enhancer factor (TCF/LEF) transcript factor, leading to the upregulation of genes associated with tumour cell proliferation, migration and stemness maintenance.22 In Cui's work, a non-canonical activator of Wnt/β-catenin signalling, namely dickkopf-related protein 4 (DKK4), was found to be upregulated along with LARP1. Through deeper investigation, the authors revealed that the competitive interaction between LARP1 and PABPC1, an important RNA-binding protein for initiating protein translation and mRNA decay, would lead to the stabilisation of DKK4 mRNA though preventing its BTG2-dependent deadenylation and degradation. By illuminating the underlying LARP1-DKK4-β-catenin cascade in HB progression, this work provoked interest in LARP1/DKK4 targeting therapies as promising strategies for HB treatment. Even though the oncogenic function of DKK4 has been concreted in several studies, some evidence also suggests that DKK4 also possesses tumour suppressive functions in specific circumstances. The Dickkopf proteins (DKKs) are generally recognised as antagonists of the Wnt signalling pathway for the prevention function of the Kremen-mediated Wnt-FZDs-LRP5/6 complex formation.23 Although the role of DKK4 is relatively controversial and less studied, the LRP5/6-binding and Wnt signalling-inhibiting capability of DKK4 has been proved, and the tumour suppressive potential of DKK4 was observed in HCC and lung cancer.24, 25 However, it could promote tumour progression by activating other non-canonical Wnt signallings, and the carcinogenic effect of DKK4 has been proven in various other cancer types. It can serve as a prognostic factor predicting poor prognosis and accelerate tumour cell progression in vitro and in vivo.26 Interestingly, DKK4-deletion was demonstrated effective in enhancing colon tumour cells' sensitivity towards chemotherapies.27 As a regulator of canonical and non-canonical Wnt pathways with a dual role in carcinogenesis, DKK4 could be involved in multiple regulatory routines on β-catenin nuclear accumulation. In summary, the development of DKK4-targeted drugs can be promising but torturous. Meanwhile, once launched, these drugs still need to be applied accurately and precisely based on the tumour types and the molecular background of the tumours. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/ctd2.210

Targeting the oncogenic LARP1/DKK4/β‐catenin axis in hepatoblastoma

Role of m6A modification in immune microenvironment of digestive system tumors.

Simple Summary Hepatoblastoma is the most common malignant pediatric tumor of the liver. Unlike hepatocellular carcinoma (HCC) which has been associated with hepatitis B virus infection or cirrhosis, the etiology of hepatoblastoma remains vague. Genetic syndromes, including familial adenomatous polyposis (FAP), Beckwith-Wiedemann syndrome (BWS), and trisomy 18 syndrome, have been associated with hepatoblastoma. BWS is an overgrowth syndrome which exhibits an alteration of genomic imprinting on chromosome 11p15.5. N6-Methyladenosine (M6A) is an RNA modification with rampant involvement in the metabolism of cells and malignant diseases. It has been observed to impact the development of various cancers via its governance of gene expression. Here, we explore the role of m6A and its genetic associates in promoting HB, and the impact this may have on our future management of the disease. Abstract Hepatoblastoma (HB) is a rare primary malignancy of the developing fetal liver. Its course is profoundly influenced by genetics, in the context of sporadic mutation or genetic syndromes. Conventionally, subtypes of HB are histologically determined based on the tissue type that is recapitulated by the tumor and the direction of its differentiation. This classification is being reevaluated based on advances on molecular pathology. The therapeutic approach comprises surgical intervention, chemotherapy (in a neoadjuvant or post-operative capacity), and in some cases, liver transplantation. Although diagnostic modalities and treatment options are evolving, some patients experience complications, including relapse, metastatic spread, and suboptimal response to chemotherapy. As yet, there is no consistent framework with which such outcomes can be predicted. N6-methyladenosine (m6A) is an RNA modification with rampant involvement in the normal processing of cell metabolism and neoplasia. It has been observed to impact the development of a variety of cancers via its governance of gene expression. M6A-associated genes appear prominently in HB. Literature data seem to underscore the role of m6A in promotion and clinical course of HB. Illuminating the pathogenetic mechanisms that drive HB are promising additions to the understanding of the clinically aggressive tumor behavior, given its potential to predict disease course and response to therapy. Implicated genes may also act as targets to facilitate the evolving personalized cancer therapy. Here, we explore the role of m6A and its genetic associates in the promotion of HB, and the impact this may have on the management of this neoplastic disease.

/pdf/the-role-of-n6-methyladenosine-in-the-promotion-of-1plzycwn.pdf

The Role of N6-Methyladenosine in the Promotion of Hepatoblastoma: A Critical Review

The value of the defence postmortem examination in England and Wales

Subnuclear vacuoles in the proximal renal tubules have been reported as a histologic sign of ketoacidosis. Originally described in diabetic ketoacidosis, renal vacuoles can be found in other ketogenic states such as alcoholic ketoacidosis (AKA), starvation, and hypothermia, underpinned by deranged fatty acid metabolism. A retrospective analysis of 133 deaths associated with alcohol use disorder (AUD) examined at autopsy between 2017 and 2020 was undertaken. This study aimed to determine the prevalence of subnuclear vacuoles in deaths of those with AUD and their specificity for deaths from AKA, and to elucidate what demographic, biochemical, and pathologic findings are associated with subnuclear vacuoles. In each case, vitreous humor biochemistry including electrolytes, glucose, and beta-hydroxybutyrate (BHB) was analyzed alongside postmortem hemoglobin A1c and renal and liver histology. Renal histology was graded for the presence of vacuoles as absent (0), scanty (1), or easily identifiable (2). Liver histology was graded for steatosis and for fibrosis if Masson trichrome staining was available. Vacuoles were commonly seen in the deaths of those with AUD. They were seen in deaths due to AKA but were not specific to that cause of death. With vacuoles present, lower vitreous sodium (139 vs. 142 mmol/L; p = 0.005), higher vitreous BHB (1.50 vs. 1.39 mmol/L; p = 0.04), severe hepatic steatosis, and severe hepatic fibrosis were seen, compared with those without renal vacuoles.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/1556-4029.15321

Finn Morgan Auld

Papers

The Role of N6-Methyladenosine in the Promotion of Hepatoblastoma: A Critical Review

The value of the defence postmortem examination in England and Wales

Subnuclear renal tubular vacuoles in alcohol use disorder.