Plasma Lipid Profiling in a Rat Model of Hepatocellular Carcinoma: Potential Modulation Through Quinolone Administration

Development of an immunosuppressed orthotopic hepatocellular carcinoma rat model for the evaluation of chemo- and radioembolization therapies

Hepatocellular carcinoma (HCC) is widely known to be chemo-resistant and presents with significant liver disease resulting in low tolerability to systemic chemotherapy. As a counter measure, more targeted therapies such as trans-arterial chemoembolization (TACE) and trans-arterial radioembolization (TARE) have been developed. To further optimize these therapies, animal models are critical in elucidating the molecular events in disease progression and test new treatment options. The present study focuses on the development of a hepatoma bearing rat model. N1S1 rat hepatoma cells were transfected by a lentiviral method and injected into the liver of Sprague Dawley (SD) and Rowett Nude (RNU) rats. Longitudinal tumor growth was observed by bioluminescence imaging (BLI) and liver/tumor histology. In both models, tumors were visible within 4 days post cell inoculation. Tumor take rates were 52 % and 73 % for male and female SD rats, respectively, and 100 % for male RNU rats. By day 12 and 15 post inoculation, we recorded complete tumor regression in male and female SD rats. Liver histology showed advanced fibrosis in the tumor regressed SD rats, whilst RNU rats exhibited the characteristic sheet pattern of Novikoff tumor with mild liver fibrosis. Increased CD3 and TUNEL staining observed in SD rat livers may be key factors for tumor regression. Our data reveal that the immunocompetent SD rats are not recommended as a model for therapeutic investigations. The immunosuppressed RNU rats, however, are characterized by consistent and reliable tumor growth and thus a desirable model for future therapeutic investigations.

New and Old Key Players in Liver Cancer

Liver cancer represents a major health problem worldwide with growing incidence and high mortality, hepatocellular carcinoma (HCC) being the most frequent. Hepatocytes are likely the cellular origin of most HCCs through the accumulation of genetic alterations, although hepatic progenitor cells (HPCs) might also be candidates in specific cases, as discussed here. HCC usually develops in a context of chronic inflammation, fibrosis, and cirrhosis, although the role of fibrosis is controversial. The interplay between hepatocytes, immune cells and hepatic stellate cells is a key issue. This review summarizes critical aspects of the liver tumor microenvironment paying special attention to platelets as new key players, which exert both pro- and anti-tumor effects, determined by specific contexts and a tight regulation of platelet signaling. Additionally, the relevance of specific signaling pathways, mainly HGF/MET, EGFR and TGF-β is discussed. HGF and TGF-β are produced by different liver cells and platelets and regulate not only tumor cell fate but also HPCs, inflammation and fibrosis, these being key players in these processes. The role of C3G/RAPGEF1, required for the proper function of HGF/MET signaling in HCC and HPCs, is highlighted, due to its ability to promote HCC growth and, regulate HPC fate and platelet-mediated actions on liver cancer.

Microbiome-Based Metabolic Therapeutic Approaches in Alcoholic Liver Disease

Alcohol consumption is a global healthcare problem. Chronic alcohol consumption generates a wide spectrum of hepatic lesions, the most characteristic of which are steatosis, hepatitis, fibrosis, and cirrhosis. Alcoholic liver diseases (ALD) refer to liver damage and metabolomic changes caused by excessive alcohol intake. ALD present several clinical stages of severity found in liver metabolisms. With increased alcohol consumption, the gut microbiome promotes a leaky gut, metabolic dysfunction, oxidative stress, liver inflammation, and hepatocellular injury. Much attention has focused on ALD, such as alcoholic fatty liver (AFL), alcoholic steatohepatitis (ASH), alcoholic cirrhosis (AC), hepatocellular carcinoma (HCC), a partnership that reflects the metabolomic significance. Here, we report on the global function of inflammation, inhibition, oxidative stress, and reactive oxygen species (ROS) mechanisms in the liver biology framework. In this tutorial review, we hypothetically revisit therapeutic gut microbiota-derived alcoholic oxidative stress, liver inflammation, inflammatory cytokines, and metabolic regulation. We summarize the perspective of microbial therapy of genes, gut microbes, and metabolic role in ALD. The end stage is liver transplantation or death. This review may inspire a summary of the gut microbial genes, critical inflammatory molecules, oxidative stress, and metabolic routes, which will offer future promising therapeutic compounds in ALD.

Piperlongumine inhibits diethylnitrosamine induced hepatocellular carcinoma in rats

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Piperlongumine (PL) has been claimed to have cytotoxic and HCC inhibitory effects in various cancer cell lines and xenograft models, but the chemopreventive potential of PL has not been studied in experimentally induced HCC yet.

RESEARCH DESIGN

Twenty-four Wistar male rats were divided into four groups of six each, Group A: untreated control; Group B: Diethylnitrosamine (DEN) control (200 mg/kg), Group C: DEN + PL 10 mg/kg; and Group D: DEN + PL 20 mg/kg. Rats from all groups were assessed for liver cancer progression or inhibition by evaluating biochemical, cytokines, tumor markers, lipid peroxidation, and histological profiles.

RESULTS

The liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP) levels, and lipid peroxidation were significantly decreased in Group C and Group D compared to Group B. Upregulation in the level of pro-inflammatory cytokines IL-1B, TNF-α, inflammatory mediator (NF-κB) and tumour marker alpha-fetoprotein (AFP) in Group B were brought down upon treatment with piperlongumine in a dose-dependent manner. Antitumor cytokine (IL-12) was upregulated in PL-treated rats compared to DEN control rats. DEN treated group (Group B) showed histological features of HCC, and in rats treated with PL (Groups C, D) partial to complete reversal to normal liver histoarchitecture was observed.

CONCLUSIONS

The potential chemopreventive actions of piperlongumine may be due to its free radical scavenging and antiproliferative effect. Therefore, piperlongumine may serve as a novel therapeutic agent for the treatment of hepatocellular carcinoma.

Plasma lipids, tumor parameters and survival in HCC patients with HBV and HCV

INTRODUCTION AND AIMS

Hepatocellular carcinoma (HCC) is a consequence of chronic liver disease, particularly from hepatitis B or C and increasingly from obesity and metabolic syndrome. Since lipids are an important component of cell membranes and are involved in cell signaling and tumor cell growth, we wished to evaluate the relationship between HCC patient plasma lipids and maximum tumor diameter and other indices of HCC human biology.

METHODS

We examined prospectively-collected data from a multi-institutional collaborative Turkish HCC working group, from predominantly HBV-based patients, for plasma lipid profiles, consisting of triglycerides, total cholesterol, LDL-cholesterol (LDL) and HDL-cholesterol (HDL) and compared these with the associated patient maximum tumor diameter (MTD), portal vein thrombosis, alpha-fetoprotein (AFP) and also with patient survival.

RESULTS

We found that both low HDL (p=0.0002) and high LDL (p=0.003) levels were significantly associated with increased MTD, as well as in a final multiple linear regression model on MTD. The combination of low HDL combined with high HDL levels were significant in a regression model on MTD, PVT and an HCC Aggressiveness Index (Odds Ratio 12.91 compared to an Odds Ratio of 1 for the reference). Furthermore, in a Cox regression model on death, the HDL plus LDL combination had a significantly higher Hazard Ratio than the reference category.

CONCLUSIONS

Low plasma HDL, high plasma LDL and especially the combination, were significantly related to more aggressive HCC phenotype and the combination was significantly related to a higher Hazard Ratio for death.

Serum metabolites may be useful markers to assess vascular invasion and identify normal alpha-fetoprotein in hepatocellular carcinoma undergoing liver resection: a pilot study

Purpose

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with a dismal prognosis. Vascular invasion, among others, is the most robust indicator of postoperative recurrence and overall survival after liver resection for HCC. Few studies to date have attempted to search for effective markers to predict vascular invasion before the operation. The current study would examine the plasma metabolic profiling via ¹H-NMR of HCC patients undergoing liver resection and aim to search for potential biomarkers in the early detection of HCC with normal alpha-fetoprotein (AFP) and the diagnosis of vascular invasion preoperatively.

Materials and methods

HCC patients scheduled to receive liver resections for their HCC were recruited and divided into two separate groups, investigation cohort and validation cohort. Their preoperative blood samples were collected and subjected to a comprehensive metabolomic profiling using ¹H-nuclear magnetic resonance spectroscopy (NMR).

Results

There were 35 HCC patients in the investigation group and 22 patients in the validation group. Chronic hepatitis B remained the most common etiology of HCC, followed by chronic HCV infection. The two study cohorts were essentially comparable in terms of major clinicopathological variables. After ¹H-nuclear NMR analysis, we found in the investigation cohort that HCC with normal alpha-fetoprotein (AFP < 15 ng/mL) had significantly higher serum level of O-acetylcarnitine than those with higher AFP (AFP ≥ 15 ng/mL, P = 0.025). In addition, HCC with microscopic vascular invasion (VI) had significantly higher preoperative serum level of formate than HCC without microscopic VI (P = 0.023). These findings were similar in the validation cohort.

Conclusion

A comprehensive metabolomic profiling of HCC demonstrated that serum metabolites may be utilized to assist the early diagnosis of AFP-negative HCC patients and recognition of microvascular invasion in order to facilitate preoperative surgical planning and postoperative follow-up. Further, larger scale prospective studies are warranted to consolidate our findings.

The mechanism of dysbiosis in alcoholic liver disease leading to liver cancer

Currently, alcoholic liver disease (ALD) is one of the most prevalent chronic liver diseases worldwide, representing one of the main etiologies of cirrhosis and hepatocellular carcinoma (HCC). Although we do not know the exact mechanisms by which only a selected group of patients with ALD progress to the final stage of HCC, the role of the gut microbiota within the progression to HCC has been intensively studied in recent years. To date, we know that alcohol-induced gut dysbiosis is an important feature of ALD with important repercussions on the severity of this disease. In essence, an increased metabolism of ethanol in the gut induced by an excessive alcohol consumption promotes gut dysfunction and bacterial overgrowth, setting a leaky gut. This causes the translocation of bacteria, endotoxins, and ethanol metabolites across the enterohepatic circulation reaching the liver, where the recognition of the pathogen-associated molecular patterns via specific Toll-like receptors of liver cells will induce the activation of the nuclear factor kappa-B pathway, which releases pro-inflammatory cytokines and chemokines. In addition, the mitogenic activity of hepatocytes will be promoted and cellular apoptosis will be inhibited, resulting in the development of HCC. In this context, it is not surprising that microbiota-regulating drugs have proven effectiveness in prolonging the overall survival of patients with HCC, making attractive the implementation of these drugs as co-adjuvant for HCC treatment.

Coenzyme Q10 attenuates rat hepatocarcinogenesis via the reduction of CD59 expression and phospholipase D activity

The current study aimed to test the profile of serum lipids, phospholipase D (PLD) activity, and CD59 expression pattern in rat hepatocellular carcinoma (HCC) after therapeutic treatment with Coenzyme Q10 (CoQ10). Three rat groups were allocated as normal control, untreated HCC, and treated HCC (HCC + CoQ10). The levels of serum α-fetoprotein (AFP) and tumour necrosis factor (TNF)-α were assessed using enzyme-linked immunosorbent assay (ELISA), while proliferating cell nuclear antigen (PCNA) was detected using immunohistochemistry (IHC). Serum lipids, classical (CH50), and alternative (APH50) pathways of complement activation, the liver cell HMG-CoA reductase (HMGCR), and PLD activities were assayed colorimetrically. The protein expression of CD59, scavenger receptor class B type 1 (SRB1), B cell lymphoma-2 (Bcl2), and cleaved Caspase-3 (Casp-3) were detected using western blotting, while the level of serum CD59 (sCD59) was assessed using dot-blot. CoQ10 reduced the cell proliferation, histological alterations, and the levels of AFP and TNF-α but increased lipids, CH50, and sCD59 in serum. In the liver cell, CoQ10 decreased and increased PLD and HMGCR enzyme activities, respectively. In addition, reduction of liver CD59, Bcl2, and SRB1 vs increased cleaved Casp-3 expressions was observed. Statistical correlation indicated an inverse relationship between CH50 and each of CD59 expression and PLD activity after treatment with CoQ10. In conclusion, CoQ10 could protect against rat HCC through increased lipids and the reduction of CD59 expression and PLD activity. SIGNIFICANCE OF THE STUDY: To our knowledge, this study is the first to describe the attenuating effect of antitumour natural product like Coenzyme Q10 (CoQ10) via the reduction of CD59 expression and phospholipase D (PLD) activity. This illustrates the important role of CD59 and PLD in relation to lipids in cancer prevention.

Animal models for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents ~90% of all cases of primary liver cancer and occurs predominantly in patients with underlying chronic liver disease and cirrhosis. Establishing appropriate animal models for HCC is required for basic and translational studies, especially the models that can recapitulate one of the human disease settings. Current animal models can be categorized as chemically-induced, genetically-engineered, xenograft, or a combination of these with each other or with a metabolic insult. A single approach to resemble human HCC in animals is not sufficient. Combining pathogenic insults in animal models may more realistically recapitulate the multiple etiologic agents occurring in humans. Combining chemical injury with metabolic disorder or alcohol consumption in mice reduces the time taken to hepatocarcinogenesis. Genetically-engineering weak activation of HCC-promoting pathways combined with disease-specific injury models will possibly mimic the pathophysiology of human HCC in distinct clinical settings.

Plasma cholesterol and lipoprotein levels in relation to tumor aggressiveness and survival in HCC patients

BACKGROUND AND AIMS:

Hepatocellular carcinoma is associated with several chronic liver diseases, especially chronic hepatitis B virus, hepatitis C virus, and alcoholism. It is increasingly appreciated that obesity/metabolic syndrome is also associated with chronic liver disease and subsequent hepatocellular carcinoma.

METHODS:

We retrospectively investigated the serum lipid profiles in a large hepatocellular carcinoma cohort, associated predominantly with the hepatitis B virus, hepatitis C virus, alcohol or nonalcoholic steatohepatitis. The cohort was examined both as a whole, as well as stratified by etiology.

RESULTS:

We found significant associations between parameters of hepatocellular carcinoma biology such as maximum tumor diameter, portal vein thrombosis, tumor multifocality or alpha-fetoprotein levels and individual lipid components, including total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides and body mass index. In a final multiple linear regression model considering all lipid variables together, only high-density lipoprotein cholesterol was significantly associated with the tumor Tumor Aggressiveness Index. High-density lipoprotein cholesterol was found to have a statistically higher hazard ratio for death than low high-density lipoprotein cholesterol levels (Cox). On examination by etiological group, alpha-fetoprotein levels were significantly higher in patients with hepatitis C virus compared to those with alcohol or nonalcoholic steatohepatitis, but maximum tumor diameter, tumor multifocality and portal vein thrombosis were similar across etiological groups. Nonalcoholic steatohepatitis patients had significantly less cirrhosis than other groups and hepatitis B virus patients had significantly higher cholesterol and low-density lipoprotein cholesterol levels than hepatitis C virus patients.

CONCLUSIONS:

This is the first report, to our knowledge, of a relationship between serum lipid parameters and indices of hepatocellular carcinoma growth, invasion and aggressiveness, as well as with survival.