Generic chemoprevention of hepatocellular carcinoma

Don't Judge a Book by Its Cover: The Role of Statins in Liver Cancer

Statins, which are inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, are an effective pharmacological tool for lowering blood cholesterol levels. This property makes statins one of the most popular drugs used primarily to prevent cardiovascular diseases, where hyperlipidemia is a significant risk factor that increases mortality. Nevertheless, studies conducted mainly in the last decade have shown that statins might prevent and treat liver cancer, one of the leading causes of cancer-related mortality worldwide. This narrative review summarizes the scientific achievements to date regarding the role of statins in liver tumors. Molecular biology tools have revealed that cell growth and proliferation can be inhibited by statins, which further inhibit angiogenesis. Clinical studies, supported by meta-analysis, confirm that statins are highly effective in preventing and treating hepatocellular carcinoma and cholangiocarcinoma. However, this effect may depend on the statin's type and dose, and more clinical trials are required to evaluate clinical effects. Moreover, their potential hepatotoxicity is a significant caveat for using statins in clinical practice. Nevertheless, this group of drugs, initially developed to prevent cardiovascular diseases, is now a key candidate in hepato-oncology patient management. The description of new drug-statin-like structures, e.g., with low toxicity to liver cells, may bring another clinically significant improvement to current cancer therapies.

Transcriptome and proteome analysis reveals the anti-cancer properties of Hypnea musciformis marine macroalga extract in liver and intestinal cancer cells

BACKGROUND

Marine seaweeds are considered as a rich source of health-promoting compounds by the food and pharmaceutical industry. Hypnea musciformis is a marine red macroalga (seaweed) that is widely distributed throughout the world, including the Mediterranean Sea. It is known to contain various bioactive compounds, including sulfated polysaccharides, flavonoids, and phlorotannins. Recent studies have investigated the potential anticancer effects of extracts from H. musciformis demonstrating their cytotoxic effects on various cancer cell lines. The anticancer effects of these extracts are thought to be due to the presence of bioactive compounds, particularly sulfated polysaccharides, which have been shown to have anticancer and immunomodulatory effects. However, further studies are needed to fully understand the molecular mechanisms that underlie their anticancer effects and to determine their potential as therapeutic agents for cancer treatment.

METHODS

H. musciformis was collected from the Aegean Sea (Greece) and used for extract preparation. Transcriptome and proteome analysis was performed in liver and colon cancer human cell lines following treatment with H. musciformis seaweed extracts to characterize its anticancer effect in detail at the molecular level and to link transcriptome and proteome responses to the observed phenotypes in cancer cells.

RESULTS

We have identified that treatment with the seaweed extract triggers a p53-mediated response at the transcriptional and protein level in liver cancer cells, in contrast to colon cancer cells in which the effects are more associated with metabolic changes. Furthermore, we show that in treated HepG2 liver cancer cells, p53 interacts with the chromatin of several target genes and facilitates their upregulation possibly through the recruitment of the p300 co-activator.

CONCLUSIONS

Overall, the available evidence suggests that extracts from H. musciformis have the potential to serve as a source of anticancer agents in liver cancer cells mainly through activation of a p53-mediated anti-tumor response that is linked to inhibition of cellular proliferation and induction of cell death.

Screening and interventions to prevent nonalcoholic fatty liver disease/nonalcoholic steatohepatitis-associated hepatocellular carcinoma

Liver cancer is the sixth most commonly diagnosed cancer worldwide, with hepatocellular carcinoma (HCC) comprising most cases. Besides hepatitis B and C viral infections, heavy alcohol use, and nonalcoholic steatohepatitis (NASH)-associated advanced fibrosis/cirrhosis, several other risk factors for HCC have been identified (i.e. old age, obesity, insulin resistance, type 2 diabetes). These might in fact partially explain the occurrence of HCC in non-cirrhotic patients without viral infection. HCC surveillance through effective screening programs is still an unmet need for many nonalcoholic fatty liver disease (NAFLD) patients, and identification of pre-cirrhotic individuals who progress to HCC represents a substantial challenge in clinical practice at the moment. Patients with NASH-cirrhosis should undergo systematic HCC surveillance, while this might be considered in patients with advanced fibrosis based on individual risk assessment. In this context, interventions that potentially prevent NAFLD/ NASH-associated HCC are needed. This paper provided an overview of evidence related to lifestyle changes (i.e. weight loss, physical exercise, adherence to healthy dietary patterns, intake of certain dietary components, etc.) and pharmacological interventions that might play a protective role by targeting the underlying causative factors and pathogenetic mechanisms. However, well-designed prospective studies specifically dedicated to NAFLD/NASH patients are still needed to clarify the relationship with HCC risk.

Hepatocellular Carcinoma Chemoprevention with Generic Agents

Liver cancer, mainly hepatocellular carcinoma (HCC), remains a major cause of cancer-related death worldwide. With the global epidemic of obesity, the major HCC etiologies have been dynamically shifting from viral to metabolic liver diseases. This change has made HCC prevention difficult with increasingly elusive at-risk populations as rational target for preventive interventions. Besides ongoing efforts to reduce obesity and metabolic disorders, chemoprevention in patients who already have metabolic liver diseases may have a significant impact on the poor HCC prognosis. Hepatitis B- and hepatitis C-related HCC incidences have been substantially reduced by the new antivirals, but HCC risk can persist over a decade even after successful viral treatment, highlighting the need for HCC-preventive measures also in these patients. Experimental and retrospective studies have suggested potential utility of generic agents such as lipophilic statins and aspirin for HCC chemoprevention given their well-characterized safety profile, although anticipated efficacy may be modest. In this review, we overview recent clinical and translational studies of generic agents in the context of HCC chemoprevention under the contemporary HCC etiologies. We also discuss newly emerging approaches to overcome the challenges in clinical testing of the agents to facilitate their clinical translation.

Hepatocellular carcinoma chemoprevention by targeting the angiotensin-converting enzyme and EGFR transactivation

Hepatocellular carcinoma (HCC) is a leading cause of death among cirrhotic patients, for which chemopreventive strategies are lacking. Recently, we developed a simple human cell-based system modeling a clinical prognostic liver signature (PLS) predicting liver disease progression and HCC risk. In a previous study, we applied our cell-based system for drug discovery and identified captopril, an approved angiotensin converting enzyme (ACE) inhibitor, as a candidate compound for HCC chemoprevention. Here, we explored ACE as a therapeutic target for HCC chemoprevention. Captopril reduced liver fibrosis and effectively prevented liver disease progression toward HCC development in a diethylnitrosamine (DEN) rat cirrhosis model and a diet-based rat model for nonalcoholic steatohepatitis–induced (NASH-induced) hepatocarcinogenesis. RNA-Seq analysis of cirrhotic rat liver tissues uncovered that captopril suppressed the expression of pathways mediating fibrogenesis, inflammation, and carcinogenesis, including epidermal growth factor receptor (EGFR) signaling. Mechanistic data in liver disease models uncovered a cross-activation of the EGFR pathway by angiotensin. Corroborating the clinical translatability of the approach, captopril significantly reversed the HCC high-risk status of the PLS in liver tissues of patients with advanced fibrosis. Captopril effectively prevents fibrotic liver disease progression toward HCC development in preclinical models and is a generic and safe candidate drug for HCC chemoprevention.

Liver cancer risk-predictive molecular biomarkers specific to clinico-epidemiological contexts

Hepatocellular carcinoma (HCC) risk prediction is increasingly important because of the low annual HCC incidence in patients with the rapidly emerging non-alcoholic fatty liver disease or cured HCV infection. To date, numerous clinical HCC risk biomarkers and scores have been reported in literature. However, heterogeneity in clinico-epidemiological context, e.g., liver disease etiology, patient race/ethnicity, regional environmental exposure, and lifestyle-related factors, obscure their real clinical utility and applicability. Proper characterization of these factors will help refine HCC risk prediction according to certain clinical context/scenarios and contribute to improved early HCC detection. Molecular factors underlying the clinical heterogeneity encompass various features in host genetics, hepatic and systemic molecular dysregulations, and cross-organ interactions, which may serve as clinical-context-specific biomarkers and/or therapeutic targets. Toward the goal to enable individual-risk-based HCC screening by incorporating the HCC risk biomarkers/scores, their assessment in patient with well-defined clinical context/scenario is critical to gauge their real value and to maximize benefit of the tailored patient management for substantial improvement of the poor HCC prognosis.

Liver cell circuits and therapeutic discovery for advanced liver disease and cancer

Hepatocellular carcinoma (HCC) is a major global health challenge with rising incidence. Despite the previous approval of several novel therapeutic approaches, HCC remains the second common cause of cancer-related death worldwide. The vast majority of HCCs arises in the context of chronic fibrotic liver diseases caused by viral or metabolic etiologies. In patients with advanced liver disease the risk of HCC persists even after viral cure or control of infection. Moreover, given the change in the lifestyle and increase of obesity and metabolic disorders, HCC incidence is predicted to drastically augment in the next decade. Early detection, improvement of the screening method in patient at-risk and development of chemopreventive strategies are therefore urgently needed to reduce HCC risk. This review summarizes the major challenges in the identification of patient at risk for HCC and the emergent strategies for HCC prevention to improve patients’ outcome.

Butyrate-containing structured lipids act on HDAC4, HDAC6, DNA damage and telomerase activity during promotion of experimental hepatocarcinogenesis

Hepatocellular carcinoma (HCC) presents with a high treatment resistance and poor prognosis. Early diagnosis and preventive approaches such as chemoprevention are essential for the HCC control. Therefore, we evaluated the chemopreventive effects of butyrate-containing structured lipids (STLs) administered during the promotion stage of hepatocarcinogenesis in rats submitted to the 'resistant hepatocyte' (RH) model. Administration of butyrate-containing STLs inhibited the incidence and mean number of visible hepatic nodules per rat and reduced the number and area of glutathione S-transferase placental form-positive (GST-P+) preneoplastic focal lesions in the livers. This was accompanied by the induction of apoptosis and an increased level of hepatic butyric acid. Treatment with butyrate-containing STLs resulted in increased histone H3 lysine 9 (H3K9) acetylation, reduction of total histone deacetylase (HDAC) activity, and lower levels of HDAC4 and HDAC6 proteins. The chemopreventive effect of butyrate-containing STLs was also associated with the increased nuclear compartmentalization of p53 protein and reduced expression of the Bcl-2 protein. In addition, rats treated with butyrate-containing STLs showed decreased DNA damage and telomerase activity in the livers. These results demonstrate that the suppressive activity of butyrate-containing STLs is associated with inhibition of elevated during hepatocarcinogenesis chromatin-modifying proteins HDAC4 and HDAC6, subcellular redistribution of the p53 protein, and decreased DNA damage and telomerase activity.

Co-Medication and Nutrition in Hepatocellular Carcinoma: Potentially Preventative Strategies in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, with about 841,000 new cases and 782,000 deaths annually. Given the clearly defined population at risk, mostly patients with liver cirrhosis, prevention of HCC could be highly effective.

SUMMARY

Besides regular ultrasound surveillance, numerous publications have suggested protective effects of diverse drugs and nutrients. However, none of those preventive options has made it into clinical routine or practice guidelines. We therefore summarize the current status of preventive effects of drugs such as statins, acetylsalicylic acid (ASA), and metformin, but also dietary aspects and nutrients such as coffee, tea, and vitamin D supplementation. A successful implementation of some of these strategies may potentially lead to improved prevention of HCC development in patients with liver cirrhosis. Key Messages: Accumulating data suggest that particularly ASA, antidiabetic therapies, and statins may substantially decrease HCC incidence in patients at risk.

Prevention of Hepatitis B Virus Infection and Liver Cancer

Hepatocellular carcinoma (HCC) is one of the five leading causes of cancer death in human. Hepatitis B virus (HBV) is the most common etiologic agent of HCC in the world. Prevention is the best way to control cancer. There are three levels of liver cancer prevention, i.e., primary prevention by HBV vaccination targeting the general population starting from birth dose, secondary prevention by antiviral agent for high-risk subjects with chronic HBV infection, and tertiary prevention by antiviral agent to prevent recurrence for patients who have been successfully treated for liver cancer. Primary prevention by hepatitis B vaccination is most cost effective, the cancer preventive efficacy support it as the first successful example of cancer preventive vaccine in human. Addition of hepatitis B immunoglobulin immediately after birth and antiviral agent during the third trimester of pregnancy to block mother-to-infant transmission of HBV are existing or possible emerging strategies to enhance the prevention efficacy of HBV infection and its related liver cancer. Secondary prevention with current antiviral agents may reduce the risk or delay the onset of HCC development, but could not eradicate HBV infection and HCC. Better antiviral therapeutic agents are needed for better secondary prevention.

Omics-derived hepatocellular carcinoma risk biomarkers for precision care of chronic liver diseases

Precise hepatocellular carcinoma (HCC) risk prediction will play increasingly important roles with the contemporary HCC etiologies, that is, non-alcoholic fatty liver disease and resolved hepatitis C virus infection. Because the HCC incidence rate in this emerging patient population is relatively low (~1% per year), identification of a subset of patients at the highest risk is critical to concentrate the effort and resources of regular HCC screening to those who most need it. Omics profiling has been derived using several candidate HCC risk biomarkers, which could refine HCC screening by enabling individual risk-based personalized or risk-stratified patient management. Various types of biomolecules have been explored as sources of information to predict HCC risk at various time horizons. Germline DNA polymorphisms likely reflect race/ethnicity- and/or etiology-specific susceptibility to HCC development or chronic liver disease progression toward carcinogenesis. Transcriptomic dysregulations in the diseased liver capture functional molecular status supporting oncogenesis such as inflammatory pathway and myofibroblast activation. Circulating nucleic acids, proteins, and metabolites could serve as less-invasive measures of molecular HCC risk. Characterization of gut microbiota could also inform HCC risk estimation. Each biomarker could have its niche of clinical application depending on logistics of use, performance, and costs with a goal to eventually improve patient prognosis as a part of the whole algorithm of chronic liver disease management.

Hepatitis C Virus and Hepatocellular Carcinoma: When the Host Loses Its Grip

Chronic infection with hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma (HCC). Novel treatments with direct-acting antivirals achieve high rates of sustained virologic response; however, the HCC risk remains elevated in cured patients, especially those with advanced liver disease. Long-term HCV infection causes a persistent and accumulating damage of the liver due to a combination of direct and indirect pro-oncogenic mechanisms. This review describes the processes involved in virus-induced disease progression by viral proteins, derailed signaling, immunity, and persistent epigenetic deregulation, which may be instrumental to develop urgently needed prognostic biomarkers and as targets for novel chemopreventive therapies.

Abnormal CD44 activation of hepatocytes with nonalcoholic fatty accumulation in rat hepatocarcinogenesis

BACKGROUND

Prevalence of nonalcoholic fatty liver disease (NAFLD) is rapidly increasing, and NAFLD has become one of the most common chronic liver diseases worldwide. With abnormal CD44 activation, the severe form of NAFLD can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Thus, the molecular mechanism of CD44 in NAFLD needs to be identified.

AIM

To investigate the relationship between CD44 activation and malignant transformation of rat hepatocytes under nonalcoholic lipid accumulation.

METHODS

Sprague-Dawley rats were fed a high-fat (HF) for 12 wk to entice NAFLD and then with HF plus 2-fluorenylacetamide (0.05%) to induce HCC. Rats were sacrificed every 2 wk, and subsequently divided into the groups based on liver pathological examination (hematoxylin and eosin staining): NAFLD, denaturation, precancerosis, HCC, and control. Liver CD44 mRNA was detected by OneArray. Liver fat as assessed by Oil red O staining or CD44 by immunohistochemical assay was compared with their integral optic density. Serum CD44, alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, and AFP levels were quantitatively tested.

RESULTS

Elevated CD44 was first reported in hepatocarcinogenesis, with increasing expression from NAFLD to HCC at the protein or mRNA level. The CD44 integral optic density values were significantly different between the control group and the NAFLD (t = 25.433, P < 0.001), denaturation (t = 48.822, P < 0.001), precancerosis (t = 27.751, P < 0.001), and HCC (t = 16.239, P < 0.001) groups, respectively. Hepatic CD44 can be secreted into the blood, and serum CD44 levels in HCC or precancerous rats were significantly higher (P < 0.001) than those in any of the other rats. Positive correlations were found between liver CD44 and CD44 mRNA (r_s = 0.373, P = 0.043) and serum CD44 (r_s = 0.541, P = 0.002) and between liver CD44 mRNA and serum CD44 (r_s = 0.507, P = 0.004). Moreover, significant correlations were found between liver CD44 and liver AFP (r_s = 0.572, P = 0.001), between serum CD44 and serum AFP (r_s = 0.608, P < 0.001), and between CD44 mRNA and AFP mRNA (r_s = 0.370, P = 0.044).

CONCLUSION

The data suggested that increasing CD44 expression is associated with the malignant transformation of hepatocytes in NAFLD.