Hepatocellular carcinoma: prevention and therapy

Circ_LDLR Knockdown Suppresses Progression of Hepatocellular Carcinoma via Modulating miR-7/RNF38 Axis

Background

Hepatocellular carcinoma (HCC) is a horrible malignancy derived from liver. Circular RNAs (circRNAs) act important roles in the pathogenesis and progression of human diseases, including HCC. The current assay intended to investigate the function of circRNA low-density lipoprotein receptor (circ_LDLR) in HCC and clarify the underlying mechanism.

Materials and Methods

Expression of circ_LDLR, microRNA (miR)-7 and ring finger protein 38 (RNF38) was determined by quantitative real-time PCR (qRT-PCR) or Western blot analysis. Flow cytometry was used to detect cell cycle distribution and apoptosis. Cell colony formation ability and viability were examined by colony formation and methyl thiazolyl tetrazolium (MTT) assays, respectively. Levels of cell proliferation and epithelia-mesenchymal transition (EMT) biomarker proteins were analyzed via Western blot assay. Cell migration and invasion were monitored by Transwell assay, and target relationship between miR-7 and circ_LDLR or RNF38 was validated by dual-luciferase reporter assay. Xenograft model was established to explore the role of circ_LDLR in vivo.

Results

Expression of circ_LDLR and RNF38 was upregulated, but miR-7 expression was downregulated in HCC tissues and cells. Circ_LDLR knockdown significantly inhibited cell proliferation, migration, invasion and EMT in HCC cells. Circ_LDLR acted as a sponge of miR-7, and interference of miR-7 could attenuate circ_LDLR knockdown-induced inhibitory effects on malignant behaviors of HCC cells. Besides, miR-7 also repressed cell proliferation and metastasis of HCC cells, by targeting RNF38. Depletion of circ_LDLR could suppress tumor growth in vivo.

Conclusion

Depletion of circ_LDLR restrained HCC cell proliferation, metastasis and tumorigenesis through the regulation on miR-7/RNF38 axis, affording a promising therapeutic target for HCC.

Hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is a leading cause of cancer-related death worldwide. In the United States, HCC is the ninth leading cause of cancer deaths. Despite advances in prevention techniques, screening, and new technologies in both diagnosis and treatment, incidence and mortality continue to rise. Cirrhosis remains the most important risk factor for the development of HCC regardless of etiology. Hepatitis B and C are independent risk factors for the development of cirrhosis. Alcohol consumption remains an important additional risk factor in the United States as alcohol abuse is five times higher than hepatitis C. Diagnosis is confirmed without pathologic confirmation. Screening includes both radiologic tests, such as ultrasound, computerized tomography, and magnetic resonance imaging, and serological markers such as α-fetoprotein at 6-month intervals. Multiple treatment modalities exist; however, only orthotopic liver transplantation (OLT) or surgical resection is curative. OLT is available for patients who meet or are downstaged into the Milan or University of San Francisco criteria. Additional treatment modalities include transarterial chemoembolization, radiofrequency ablation, microwave ablation, percutaneous ethanol injection, cryoablation, radiation therapy, systemic chemotherapy, and molecularly targeted therapies. Selection of a treatment modality is based on tumor size, location, extrahepatic spread, and underlying liver function. HCC is an aggressive cancer that occurs in the setting of cirrhosis and commonly presents in advanced stages. HCC can be prevented if there are appropriate measures taken, including hepatitis B virus vaccination, universal screening of blood products, use of safe injection practices, treatment and education of alcoholics and intravenous drug users, and initiation of antiviral therapy. Continued improvement in both surgical and nonsurgical approaches has demonstrated significant benefits in overall survival. While OLT remains the only curative surgical procedure, the shortage of available organs precludes this therapy for many patients with HCC.

Chemoprevention of hepatocellular carcinoma in patients with hepatitis C virus related cirrhosis

Interferon (IFN) therapy has been reported to decrease the risk of hepatocellular carcinoma (HCC) and improve survival by preventing liver-related deaths in patients with chronic hepatitis C virus (HCV) infection, while the role of IFN therapy on the natural history of hepatitis C related cirrhosis is still under debate. The ideal goal of therapy is to prevent the progression into end-stage disease. The use of IFN in patients with HCV compensated cirrhosis reduces the negative clinical evolution independently of the type of laboratoristic and virological response. In our experience, IFN therapy in HCV compensated cirrhosis is barely useful in prevention of HCC, as cirrhosis itself represents a risk of cancer. Some authors noted that IFN treatment reduces the risk of HCC independently of the virological response. It would probably be interesting to evaluate the efficacy of weekly low-dose pegylated (PEG)-IFN therapy in patients with HCV cirrhosis and to assess potential benefits of long-term PEG-IFN plus Ribavirin treatment.

Thymoquinone inhibits cell proliferation through regulation of G1/S phase cell cycle transition in N-nitrosodiethylamine-induced experimental rat hepatocellular carcinoma

Dysregulated cell proliferation and tumorigenesis is frequently encountered in several cancers including hepatocellular carcinogenesis (HCC). Thus, agents that inhibit cell proliferation and restrain hepatic tumorigenesis through cell cycle regulation have a beneficial effect in the treatment of hepatocellular carcinogenesis. The present study was aimed to investigate the efficacy of thymoquinone (TQ), an active compound derived from the medicinal plant Nigella sativa, on N-nitrosodiethylamine (NDEA) [0.01% in drinking water for 16 weeks]-induced hepatocarcinogenesis in experimental rats. After experimental period, the hepatic nodules, liver injury markers and tumor markers levels were substantially increased in NDEA induced liver tumors in rats. However, TQ (20mg/kg body weight) treatment greatly reduced liver injury markers and decreased tumor markers and prevented hepatic nodule formation and reduced tumor multiplicity in NDEA induced hepatic cancer bearing rats and this was evident from argyrophilic nucleolar organizer region (AgNORs) staining. Moreover, the uncontrolled cell proliferation was assessed by specific cell proliferative markers [proliferating cell nuclear antigen (PCNA) and Ki67] by immunofluorescence, immunoblot and analysis of mRNA expression. Simultaneously, we assessed the activity of TQ on G1/S phase cell cycle regulation with specific cell cycle proteins (p21(WAF1/CIP1), CDK4, Cyclin D1 and Cyclin E) by immunoprecipitation in experimental rats. Treatment with TQ significantly reduced the detrimental alterations by abrogating cell proliferation, which strongly induced G1/S arrest in cell cycle transition. In conclusion, our results suggest that TQ has a potent anti proliferative activity by regulating the G1/S phase cell cycle transition and exhibit a beneficial role in the treatment of HCC.

Hepatocellular carcinoma and other malignancies in autoimmune hepatitis

Hepatocellular carcinoma and extrahepatic malignancies can complicate the course of autoimmune hepatitis, and these occurrences may increase in frequency as the survival of patients with cirrhosis is extended and the prospect of new nonstandard immune-modifying intervention is realized. The frequency of hepatocellular carcinoma in patients with autoimmune hepatitis and cirrhosis is 1-9 %, and annual occurrence in patients with cirrhosis is 1.1-1.9 %. The standardized incidence ratio for hepatocellular carcinoma in autoimmune hepatitis is 23.3 (95 % confidence interval (CI) 7.5-54.3) in Sweden, and the standardized mortality ratio for hepatobiliary cancer is 42.3 (95 % CI 20.3-77.9) in New Zealand. The principal risk factor is long-standing cirrhosis, and patients at risk are characterized mainly by cirrhosis for ≥ 10 years, manifestations of portal hypertension, persistent liver inflammation, and immunosuppressive therapy for ≥ 3 years. Multiple molecular disturbances, including the accumulation of senescent hepatocytes because of telomere shortening, step-wise accumulation of chromosomal injuries, and aberrations in transcription factors and genes, may contribute to the risk. Extraheptic malignancies of diverse cell types occur in 5 % in an unpredictable fashion. The standardized incidence ratio is 2.7 (95 % CI 1.8-3.9) in New Zealand, and non-melanoma skin cancers are most common. Outcomes are related to the nature and stage of the tumor at diagnosis. Surveillance recommendations have not been promulgated, but hepatic ultrasonography every six months in patients with cirrhosis is a consideration. Routine health screening measures for other malignancies should be applied diligently.

Socioeconomic status and hepatocellular carcinoma in the United States

BACKGROUND

Hepatocellular carcinoma (HCC) has a poor prognosis and, unlike most cancers, HCC incidence and mortality rates are increasing in the United States. While risk is known to vary among different racial and ethnic groups, less is known about the variability of risk within these groups by neighborhood socioeconomic status (SES).

METHODS

HCC cases diagnosed in the Surveillance, Epidemiology and End Results (SEER) 11 cancer registries between 1996 and 2007, and the population of the SEER 11 catchment areas was studied. Analyses were conducted to compare census tract area family poverty, educational attainment, and unemployment by race and ethnicity. A multiple linear regression model, weighted by the number of cases and the number of individuals in each census tract, with adjustment for registry, was used to calculate mean differences in area-level attributes between HCC cases and the population.

RESULTS

HCC cases in most racial/ethnic groups had lower mean neighborhood-level measures of SES than their referent population. An exception was seen among Hispanics. Comparing white cases with cases of other racial groups and to Hispanics, white cases lived in neighborhoods with less family poverty, fewer high-school dropouts, and lower unemployment. Compared with white cases, Asian and Pacific Islander and Hispanic cases lived in neighborhoods with a higher percentage of foreign-born population.

CONCLUSIONS

Low neighborhood-level SES and immigrant status may be associated with greater risk of HCC within specific racial and ethnic groups.

IMPACT

These findings could help to focus control resources for HCC toward the most affected communities.

Hepatocellular carcinoma: natural history, current management, and emerging tools

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and represents the third-leading cause of cancer-related death in the world. The incidence of HCC continues to increase worldwide, with a unique geographic, age, and sex distribution. The most important risk factor associated with HCC is liver cirrhosis, with the majority of cases caused by chronic infection with hepatitis B (HBV) and C (HCV) viruses and alcohol abuse, although nonalcoholic fatty liver disease is emerging as an increasingly important cause. Primary prevention in the form of HBV vaccination has led to a significant decrease in HBV-related HCC, and initiation of antiviral therapy appears to reduce the incidence of HCC in patients with chronic HBV or HCV infection. Additionally, the use of ultrasonography enables the early detection of small liver tumors and forms the backbone of recommended surveillance programs for patients at high risk for the development of HCC. Cross-sectional imaging studies, including computed tomography and magnetic resonance imaging, represent further noninvasive techniques that are increasingly employed to diagnose HCC in patients with cirrhosis. The mainstay of potentially curative therapy includes surgery – either resection or liver transplantation. However, most patients are ineligible for surgery, because of either advanced disease or underlying liver dysfunction, and are managed with locoregional and/or systemic therapies. Randomized controlled trials have demonstrated a survival benefit with both local therapies, either ablation or embolization, and systemic therapy in the form of the multikinase inhibitor sorafenib. Despite this, median survival remains poor and recurrence rates significant. Further advances in our understanding of the molecular pathogenesis of HCC hold promise in improving the diagnosis and treatment of this highly lethal cancer.