Antonio Solinas

Hepatocellular carcinoma (HCC) is the most common type of liver cancer and has limited treatment options. Snail family transcriptional repressor 1 (SNAI1) is a master regulator of epithelial–mesenchymal transition (EMT) and has been implicated in HCC initiation and progression. However, the precise role of SNAI1 and the way it contributes to hepatocarcinogenesis have not been investigated in depth, especially in vivo. Here, we analyzed the functional relevance of SNAI1 in promoting hepatocarcinogenesis in the context of the AKT/c-Met–driven mouse liver tumor model (AKT/c-Met/SNAI1). Overexpression of SNAI1 did not accelerate AKT/c-Met–induced HCC development or induce metastasis in mice. Elevated SNAI1 expression rather led to the formation of cholangiocellular (CCA) lesions in the mouse liver, a phenotype that was paralleled by increased activation of Yap and Notch. Ablation of Yap strongly inhibited AKT/c-Met/SNAI-induced HCC and CCA development, whereas inhibition of the Notch pathway specifically blocked the CCA-like phenotype in mice. Intriguingly, overexpression of SNAI1 failed to induce EMT, indicated by strong E-cadherin expression and lack of vimentin expression by AKT/c-Met/SNAI tumor cells. SNAI1 mRNA levels strongly correlated with the expression of CCA markers, including SOX9, CK19, and EPCAM, but not with EMT markers such as E-CADHERIN and ZO-1, in human HCC samples. Overall, our findings suggest SNAI1 regulates the CCA-like phenotype in hepatocarcinogenesis via regulation of Yap and Notch. Significance: These findings report a new function of SNAI1 to promote cholangiocellular transdifferentiation instead of epithelial–mesenchymal transition in hepatocellular carcinoma.

Tumour microenvironment is a complex, multicellular functional compartment that, particularly when assembled as an abundant desmoplastic reaction, may profoundly affect the proliferative and invasive abilities of epithelial cancer cells. Tumour microenvironment comprises not only stromal cells, mainly cancer‐associated fibroblasts, but also immune cells of both the innate and adaptive system (tumour‐associated macrophages, neutrophils, natural killer cells, and T and B lymphocytes), and endothelial cells. This results in an intricate web of mutual communications regulated by an extensively remodelled extracellular matrix, where the tumour cells are centrally engaged. In this regard, cholangiocarcinoma, in particular the intrahepatic variant, has become the focus of mounting interest in the last years, largely because of the lack of effective therapies despite its rising incidence and high mortality rates worldwide. On the other hand, recent studies in pancreatic cancer, which similarly to cholangiocarcinoma, is highly desmoplastic, have argued against a tumour‐promoting function of the tumour microenvironment. In this review, we will discuss recent developments concerning the role of each cellular population and their multifaceted interplay with the malignant biliary epithelial counterpart. We ultimately hope to provide the working knowledge on how their manipulation may lead to a therapeutic gain in cholangiocarcinoma.

Background & Aims: Although it is well established that fatty acids (FA) are indispensable for the proliferation and survival of cancer cells in hepatocellular carcinoma (HCC), inhibition of Fatty Acid Synthase (FASN) cannot completely repress HCC cell growth in culture. Thus, we hypothesized that uptake of exogenous FA by cancer cells might play an important role in the development and progression of HCC. Lipoprotein lipase (LPL) is the enzyme that catalyses the hydrolysis of triglycerides into free fatty acids (FFA) and increases the cellular uptake of FA.Methods: We used immunohistochemistry and quantitative reverse transcription real‐time polymerase chain reaction to evaluate LPL expression in human and mouse HCC samples. Using lipoprotein‐deficient medium as well as siRNAs against LPL and/or FASN, we investigated whether human HCC cells depend on both endogenous and exogenous fatty acids for survival in vitro.Results: We found that LPL is upregulated in mouse and human HCC samples. High expression of LPL in human HCC samples is associated with poor prognosis. In HCC cell lines, silencing of FASN or LPL or culturing the cells in lipoprotein‐deficient medium significantly decreased cell proliferation. Importantly, when FASN suppression was coupled to concomitant LPL depletion, the growth restraint of cell lines was further augmented.Conclusions: The present study strongly suggests that both de novo synthetized and exogenous FA play a major role along hepatocarcinogenesis. Thus, combined suppression of LPL and FASN might be highly beneficial for the treatment of human HCC.

Cognitive dysfunction in patients with chronic hepatitis C virus (HCV) infection is a distinct form of minimal hepatic encephalopathy (MHE). In fact, the majority of HCV-positive patients, irrespective of the grading of liver fibrosis, display alterations of verbal learning, attention, executive function, and memory when they are evaluated by suitable neuropsychological tests. Similarities between the cognitive dysfunction of HCV patients and MHE of patients with different etiologies are unclear. It is also unknown how the metabolic alterations of advanced liver diseases interact with the HCV-induced cognitive dysfunction, and whether these alterations are reversed by antiviral therapies. HCV replication in the brain may play a role in the pathogenesis of neuroinflammation. HCV-related brain dysfunction may be associated with white matter neuronal loss, alterations of association tracts and perfusion. It is unclear to what extent, in patients with cirrhosis, HCV triggers an irreversible neurodegenerative brain damage. New insights on this issue will be provided by longitudinal studies using the protocols established by the diagnostic and statistical manual of mental disorders fifth edition for cognitive disorders. The domains to be evaluated are complex attention; executive functions; learning and memory; perceptual motor functions; social cognition. These evaluations should be associated with fluorodeoxyglucose positron emission tomography and magnetic resonance imaging (MRI) protocols for major cognitive disorders including magnetic resonance spectroscopy, diffusion tensor imaging, magnetic resonance perfusion, and functional MRI. Also, the characteristics of portal hypertension, including the extent of liver blood flow and the type of portal shunts, should be evaluated.

In this review we focus on lymphoepithelioma-like hepatocellular carcinomas (LEL-HCC) and lymphoepithelioma-like cholangiocarcinomas (LEL-ICC). Despite their rarity, these tumors are of general interest because of their epidemiological and clinical features, and because they represent a distinct model of interaction between the immune system and neoplastic cells. Approximately half of LEL-HCC arise in the context of chronic hepatitis C virus (HCV) infection and have been described both in Eastern and Western patients. By contrast, LEL-ICC is associated in almost all cases with Epstein-Barr virus (EBV) infection and exhibits the same epidemiological features of EBV related malignancies. Compared with classical hepatocellular carcinoma and intrahepatic cholangiocarcinoma of corresponding stage, both LEL-HCC and LEL-ICC are characterized by lower rates of recurrence after surgery and better overall survival. How this behavior is related to distinct genetic alterations and tumor microenvironment is unclear. The pathophysiological mechanisms of lymphoid infiltrations seem to be different among the two groups of tumors. In fact, LEL-HCC frequently arises in the context of inflammatory changes driven by HCV infection, and has been recognized as a variant of classical hepatocellular carcinoma. At variance, lymphocyte recruitment of LEL-ICC is similar to that described in nasopharyngeal carcinoma and gastric LEL, and possibly depends on the expression pattern of latent EBV infection.

Herein we report the results of mutation analysis of the ATP7B gene in a group of 134 Wilson disease (WD) families (268 chromosomes) prevalently of Italian origin. Using the SSCP and sequencing methods we identified 71 disease-causing mutations. Twenty-four were novel, while 19 more mutations already described, were identified in new populations in this study. A known mutation G591D showed a regional distribution, since it was only detected in 38.5% of the analyzed chromosomes in WD patients originating from Apulia, a region of South Italy. Detection of new mutations in the ATP7B gene increases our capability of molecular analysis that is essential for early diagnosis and treatment of WD.