Liver angiogenesis as a risk factor for hepatocellular carcinoma development in hepatitis C virus cirrhotic patients

DNMT1-induced miR-378a-3p silencing promotes angiogenesis via the NF-κB signaling pathway by targeting TRAF1 in hepatocellular carcinoma

BACKGROUND

Angiogenesis plays an important role in the occurrence, development and metastasis of hepatocellular carcinoma (HCC). According to previous studies, miR-378a participates in tumorigenesis and tumor metastasis, but its exact role in HCC angiogenesis remains poorly understood.

METHODS

qRT-PCR was used to investigate the expression of miR-378a-3p in HCC tissues and cell lines. The effects of miR-378a-3p on HCC in vitro and in vivo were examined by Cell Counting Kit-8 (CCK-8), Transwell, tube formation and Matrigel plug assays, RNA sequencing, bioinformatics, luciferase reporter, immunofluorescence and chromatin immunoprecipitation (ChIP) assays were used to detect the molecular mechanism by which miR-378a-3p inhibits angiogenesis.

RESULTS

We confirmed that miR-378a-3p expression was significantly downregulated and associated with higher microvascular density (MVD) in HCC; miR-378a-3p downregulation indicated a short survival time in HCC patients. miR-378a-3p knockdown led to a significant increase in angiogenesis in vitro and in vivo. We found that miR-378a-3p directly targeted TNF receptor associated factor 1 (TRAF1) to attenuate NF-κB signaling, and then downregulated secreted vascular endothelial growth factor. DNA methyltransferase 1 (DNMT1)-mediated hypermethylation of miR-378a-3p was responsible for downregulating miR-378a-3p. Moreover, a series of investigations indicated that p65 initiated a positive feedback loop that could upregulate DNMT1 to promote hypermethylation of the miR-378a-3p promoter.

CONCLUSION

Our study indicates a novel DNMT1/miR-378a-3p/TRAF1/NF-κB positive feedback loop in HCC cells, which may become a potential therapeutic target for HCC.

Hepatocellular carcinoma: Where are we?

Hepatocellular carcinoma (HCC) is the second cause of death due to malignancy in the world, following lung cancer. The geographic distribution of this disease accompanies its principal risk factors: Chronic hepatitis B virus and hepatitis C virus infection, alcoholism, aflatoxin B1 intoxication, liver cirrhosis, and some genetic attributes. Recently, type II diabetes has been shown to be a risk factor for HCC together with obesity and metabolic syndrome. Although the risk factors are quite well known and it is possible to diagnose HCC when the tumor is less than 1 cm diameter, it remains elusive at the beginning and treatment is often unsuccessful. Liver transplantation is thus far considered the best treatment for HCC as it cures HCC and the underlying liver disease. Using the Milan criteria, overall survival after liver transplantation for HCC is about 70% after 5 years. Many attempts have been made to go beyond the Milan Criteria and according to recent works reasonably good results have been achieved by using a histochemical marker such as cytokeratine 19 and the so-called "up to seven criteria" to divide patients into categories according to their risk of relapse. In addition to liver transplantation other therapies have been proposed such as resection, tumor ablation by different means, embolization and chemotherapy. An important step in the treatment of advanced HCC has been the introduction of sorafenib, the first oral, systemic drug that has provided significant improvement in survival. Treatment of HCC patients must be multidisciplinary and by using the different approaches discussed in this review it is possible to offer prolonged survival and quite good and sometimes even excellent quality of life to many patients.

Effect of long-term propranolol treatment on hepatocellular carcinoma incidence in patients with HCV-associated cirrhosis

Propranolol bears antioxidant, anti-inflammatory, and antiangiogenic properties and antitumoral effects and therefore is potentially active in the prevention of hepatocellular carcinoma (HCC). We retrospectively assessed the impact of propranolol treatment on HCC occurrence in a cohort of 291 patients with compensated viral C (HCV) cirrhosis, prospectively followed and screened for HCC detection. Of the 291 patients included in the cohort, 93 patients [50 males: mean age, 59.5 ± 12 years; body mass index (BMI), 25.7 ± 4.4 kg/m(2); and platelet count, 111 ± 53 Giga/L] developed esophageal varices (OV) or had OV at inclusion and 198 patients (111 males: mean age, 55.8 ± 13 years; BMI, 25.7 ± 5 kg/m(2); platelet count, 137 ± 59 Giga/L) did not. Among patients with OV, 50 received treatment by propranolol. During a median follow-up of 54 months interquartile range (32-82), 61 patients developed an HCC. The 3- and 5-year HCC incidence was 4% and 4%, and 10% and 20% for patients treated and not treated by propranolol, respectively (Gray test, P = 0.03). In multivariate analysis, propranolol treatment was associated with a decrease risk of HCC occurrence [HR, 0.25; 95% confidence interval (CI), 0.09-0.65; P = 0.004], and was the only independent predictive factor of HCC occurrence in patients with OV (HR, 0.16; CI, 0.06-0.45; P = 0.0005). The benefit of propranolol was further supported by propensity scores analyses.

CONCLUSION

This retrospective long-term observational study suggests that propranolol treatment may decrease HCC occurrence in patients with HCV cirrhosis. These findings need to be verified by prospective clinical trial.

Prevalence and challenges of liver diseases in patients with chronic hepatitis C virus infection

Hepatitis C virus (HCV) infections pose a growing challenge to health care systems. Although chronic HCV infection begins as an asymptomatic condition with few short-term effects, it can progress to cirrhosis, hepatic decompensation, hepatocellular carcinoma (HCC), and death. The rate of new HCV infections is decreasing, yet the number of infected people with complications of the disease is increasing. In the United States, people born between 1945 and 1964 (baby boomers) are developing more complications of infection. Men and African Americans have a higher prevalence of HCV infection. Progression of fibrosis can be accelerated by factors such as older age, duration of HCV infection, sex, and alcohol intake. Furthermore, insulin resistance can cause hepatic steatosis and is associated with fibrosis progression and inflammation. If more effective therapies are not adopted for HCV, more than 1 million patients could develop HCV-related cirrhosis, hepatic decompensation, or HCC by 2020, which will impact the US health care system. It is important to recognize the impact of HCV on liver disease progression and apply new therapeutic strategies.

A somatostatin analogue, octreotide, inhibits the occurrence of second primary tumors and lung metastasis after resection of hepatocellular carcinoma in mice

Occurrence of second primary tumors and metastasis remains the major obstacles to prolonged survival of patients with primary hepatocellular carcinoma (HCC). A somatostatin analogue, octreotide, has been previously reported to inhibit the growth of human HCC xenografts in nude mice through its anti-angiogenic activity. It is therefore important to investigate whether octreotide could prevent second primary hepatomas or distant metastasis following resection of primary HCC. In this study, nude mice, bearing the human HCC xenografts with highly metastatic potential (LCI-D20) in the left liver lobe, underwent tumor resection, and received intraperitoneal administration of octreotide or saline as a control for 35 consecutive days. Compared with the control group, octreotide at the doses of 100 and 200 microg/kg/day significantly inhibited the growth (P < 0.001 and P < 0.001, respectively) and incidence of second primary tumors (P = 0.016 and P = 0.001, respectively), decreased lung metastasis (P < 0.001 and P < 0.001, respectively), and prolonged the life span (P = 0.029 and P = 0.006, respectively). Moreover, intratumoral angiogenesis quantified by microvessel density as well as serum and tissue vascular endothelial growth factor (VEGF) levels were considerably decreased in octreotide-treated animals compared to the control animals. These findings suggest that octreotide may prevent the occurrence of second primary hepatomas and lung metastasis after resection of primary HCC, which may be partially attributed to down-regulation of VEGF and subsequent reduction in tumor angiogenesis. Octreotide administration may be useful as an adjuvant therapy to improve survival of patients with HCC.

Leptin-leptin receptor are involved in angiogenesis in human hepatocellular carcinoma

Recent evidence in vitro and in vivo indicates that leptin, an adipose tissue-secreted hormone which is involved in the regulation of satiety, metabolic rate and thermogenesis, is implicated in angiogenesis. However, the role of leptin-mediated angiogenesis in hepatic carcinogenesis has not yet been completely elucidated. In this study, we have correlated microvascular density and leptin/leptin receptor (Ob-R) expression in endothelial and tumor cells with the histopathological type in human hepatocellular carcinoma (HCC). For this purpose, specimens of 40 primary HCC were submitted to immunohistochemical investigation using anti-CD31, anti-leptin and anti-Ob-R antibodies. Poorly-differentiated HCC had a higher degree of vascularization than other stages and leptin/Ob-R expression in both tumor and endothelial cells increased in parallel with the grade of malignancy and was highly correlated with the degree of angiogenesis. In the chick embryo chorioallantoic membrane in vivo assay, HCC biopsy specimens induced a strong angiogenic response, which was counteracted by an anti-leptin antibody. Taken together, these findings indicate that leptin/Ob-R correlate with angiogenesis and tumor progression in patients with HCC and that an anti-leptin antibody exerts an angiostatic activity in HCC.

Hepatocellular carcinoma: epidemiology and clinical aspects

Liver cancer is one of the most frequent solid cancers that kills more than 650,000 people around the world each year. Though great improvements have been done in last 10 years on the understanding the molecular mechanisms involved in liver oncogenesis, the prognosis of patients affected by liver cancer is still poor for most of them. Even in those where a relatively early diagnosis is done, the course of the disease is often fatal due to the underlying liver cirrhosis. In this review authors report the most recent findings on the pathogenesis of liver cancer and on therapeutic approaches, included those emerging from the most recent literature.