Nanoparticle Delivery of miR-122 Inhibits Colorectal Cancer Liver Metastasis.

Liver metastasis is a leading cause of cancer morbidity and mortality. Thus, there has been strong interest in the development of therapeutics that can effectively prevent liver metastasis. One potential strategy is to utilize molecules that have broad effects on the liver microenvironment, such as miR-122, a liver-specific miRNA that is a key regulator of diverse hepatic functions. Here we report the development of a nanoformulation miR-122 as a therapeutic agent for preventing liver metastasis. We engineered a galactose-targeted lipid calcium phosphate (Gal-LCP) nanoformulation of miR-122. This nanotherapeutic elicited no significant toxicity and delivered miR-122 into hepatocytes with specificity and high efficiency. Across multiple colorectal cancer liver metastasis models, treatment with Gal-LCP miR-122 treatment effectively prevented colorectal cancer liver metastasis and prolonged survival. Mechanistic studies revealed that delivery of miR-122 was associated with downregulation of key genes involved in metastatic and cancer inflammation pathways, including several proinflammatory factors, matrix metalloproteinases, and other extracellular matrix degradation enzymes. Moreover, Gal-LCP miR-122 treatment was associated with an increased CD8+/CD4+ T-cell ratio and decreased immunosuppressive cell infiltration, which makes the liver more conducive to antitumor immune response. Collectively, this work presents a strategy to improve cancer prevention and treatment with nanomedicine-based delivery of miRNA. SIGNIFICANCE: Highly specific and efficient delivery of miRNA to hepatocytes using nanomedicine has therapeutic potential for the prevention and treatment of colorectal cancer liver metastasis.

The role of liver microenvironment in hepatic metastasis.

Metastasis is still poorly understood and thus further research must be conducted to provide insight into the driving factors. Novel research has revealed the significance of the microenvironment in the delegation of metastasis, expanding the field of cancer metastasis to cells and cell environments surrounding the migrated tumor cells. Research on hepatic metastasis is an ever-growing domain of this field, as several primary tumors can metastasize to the liver. The two features within the liver that promote metastasis-cellular and acellular-are found in the current interpretation of liver microenvironment. Novel findings of both are included in this review. Different hypotheses detailing the methods by which metastasis can occur must be included to understand the significance of the microenvironment, as well as a brief overview of the methods that can be used during research. This review aims to highlight the importance of liver microenvironment on the development or potential regression of hepatic metastasis through discussing both acellular and cellular components of liver microenvironment and their interaction with metastasis.

miR-122 inhibition in a human liver organoid model leads to liver inflammation, necrosis, steatofibrosis and dysregulated insulin signaling.

To investigate the role of miR-122 in the development and regression of non-alcoholic fatty liver disease (NAFLD) in vitro, we used multicellular 3D human liver organoids developed in our laboratory. These organoids consist of primary human hepatocytes, Kupffer cells, quiescent stellate cells and liver sinusoidal endothelial cells. They remain viable and functional for 4 weeks expressing typical markers of liver function such as synthesis of albumin, urea, and alpha-1 p450 drug metabolism. Before mixing, hepatic cells were transduced with lentivirus to inhibit miR122 expression (ABM, CA). Immediately after the organoids were fully formed (day 4) or after 1 or 2 weeks of additional incubation (days 11 or 18), the organoids were analyzed using fluorescent live/dead staining and ATP production; total RNA was extracted for qPCR gene expression profiling. Our results show that miR-122 inhibition in liver organoids leads to inflammation, necrosis, steatosis and fibrosis. This was associated with increase in inflammatory cytokines (IL6, TNF), chemokines (CCL2, CCL3) and increase in a subset of Matrix Metaloproteinases (MMP8, MMP9). An altered expression of key genes in lipid metabolism (i.e LPL, LDLR) and insulin signaling (i.e GLUT4, IRS1) was also identified. CONCLUSION: Our results highlight the role of miR-122 inhibition in liver inflammation, steatofibrosis and dysregulation of insulin signaling. Patients with NAFLD are known to have altered levels of miR-122, therefore we suggest that miR-122 mimics could play a useful role in reversing liver steatofibrosis and insulin resistance seen in patients with NAFLD.

Hepatitis B and liver transplantation: molecular and clinical features that influence recurrence and outcome.

Hepatitis B virus (HBV) continues to be a major cause of morbidity and mortality worldwide. It is estimated that about 350 million people throughout the world are chronically infected with HBV. Some of these people will develop hepatic cirrhosis with decompensation and/or hepatocellular carcinoma. For such patients, liver transplantation may be the only hope for cure or real improvement in quality and quantity of life. Formerly, due to rapidity of recurrence of HBV infection after liver transplantation, usually rapidly progressive, liver transplantation was considered to be contraindicated. This changed dramatically following the demonstration that hepatitis B immune globulin (HBIG), could prevent recurrent HBV infection. HBIG has been the standard of care for the past two decades or so. Recently, with the advent of highly active inhibitors of the ribose nucleic acid polymerase of HBV (entecavir, tenofovir), there has been growing evidence that HBIG needs to be given for shorter lengths of time; indeed, it may no longer be necessary at all. In this review, we describe genetic variants of HBV and past, present, and future prophylaxis of HBV infection during and after liver transplantation. We have reviewed the extant medical literature on the subject of infection with the HBV, placing particular emphasis upon the prevention and treatment of recurrent HBV during and after liver transplantation. For the review, we searched PubMed for all papers on the subject of "hepatitis B virus AND liver transplantation". We describe some of the more clinically relevant and important genetic variations in the HBV. We also describe current practices at our medical centers, provide a summary and analysis of comparative costs for alternative strategies for prevention of recurrent HBV, and pose important still unanswered questions that are in need of answers during the next decade or two. We conclude that it is now rational and cost-effective to decrease and, perhaps, cease altogether, the routine use of HBIG during and following liver transplantation for HBV infection. Here we propose an individualized prophylaxis regimen, based on an integrated approach and risk-assessment.

Dual Role of miR-122 in Molecular Pathogenesis of Viral Hepatitis.

The hepatic microRNA (miRNA), miR-122, is the most abundant miRNA within the liver, where it accounts for 70% of the total miRNA pool. It is known that miR-122, as an unusual host factor, increases the abundance of hepatitis C virus (HCV) RNA in HCV infection by binding directly to the 5'-UTR of the viral genome. Therefore, it has been suggested as a potential target for the treatment of hepatitis C. However, recent evidence shows that miR-122 decreases HBV replication through the inhibitory effect of p53 on HBV transcription, and consequently it acts as a tumor-suppressor through both a decrease in HBV replication and by directly targeting cyclin G1, as well as Wnt/beta-catenin, and NDRG3 pathways. This paper will briefly discuss the underlying mechanisms for the dual role of miR-122 in viral hepatitis, and explains why therapeutic applications of miR-122 may differ based on the underlying disease.

Hepatitis C, porphyria cutanea tarda and liver iron: an update.

Porphyria cutanea tarda (PCT) is the most common form of porphyria across the world. Unlike other forms of porphyria, which are inborn errors of metabolism, PCT is usually an acquired liver disease caused by exogenous factors, chief among which are excess alcohol intake, iron overload, chronic hepatitis C, oestrogen therapy and cigarette smoking. The pathogenesis of PCT is complex and varied, but hereditary or acquired factors that lead to hepatic iron loading and increased oxidative stress are of central importance. Iron loading is usually only mild or moderate in degree [less than that associated with full-blown haemochromatosis (HFE)] and is usually acquired and/or mutations in HFE. Among acquired factors are excessive alcohol intake and chronic hepatitis C infection, which, like mutations in HFE, decrease hepcidin production by hepatocytes. The decrease in hepcidin leads to increased iron absorption from the gut. In the liver, iron loading and increased oxidative stress leads to the formation of non-porphyrin inhibitor(s) of uroporphyrinogen decarboxylase and to oxidation of porphyrinogens to porphyrins. The treatment of choice of active PCT is iron reduction by phlebotomy and maintenance of a mildly iron-reduced state without anaemia. Low-dose antimalarials (cinchona alkaloids) are also useful as additional therapy or as alternative therapy for active PCT in those without haemochromatosis or chronic hepatitis C. In this review, we provide an update of PCT with special emphasis upon the important role often played by the hepatitis C virus.

Legalon-SIL downregulates HCV core and NS5A in human hepatocytes expressing full-length HCV.

AIM: To determine the effect of Legalon-SIL (LS) on hepatitis C virus (HCV) core and NS5A expression and on heme oxygenase-1 (HMOX-1) and its transcriptional regulators in human hepatoma cells expressing full length HCV genotype 1b. METHODS: CON1 cells were treated with 50 µmol/L or 200 µmol/L LS. Cells were harvested after 2, 6 and 24 h. HCV RNA and protein levels were determined by quantitative real-time polymerase chain reaction and Western blotting, respectively. RESULTS: HCV RNA (core and NS5A regions) was decreased after 6 h with LS 200 µmol/L (P < 0.05). Both 50 and 200 µmol/L LS decreased HCV RNA levels [core region (by 55% and 88%, respectively) and NS5A region (by 62% and 87%, respectively) after 24 h compared with vehicle (dimethyl sulphoxide) control (P < 0.01). Similarly HCV core and NS5A protein were decreased (by 85%, P < 0.01 and by 65%, P < 0.05, respectively) by LS 200 µmol/L. Bach1 and HMOX-1 RNA were also downregulated by LS treatment (P < 0.01), while Nrf2 protein was increased (P < 0.05). CONCLUSION: Our results demonstrate that treatment with LS downregulates HCV core and NS5A expression in CON1 cells which express full length HCV genotype 1b, and suggests that LS may prove to be a valuable alternative or adjunctive therapy for the treatment of HCV infection.

Serum measures of iron status and HFE gene mutations in patients with hepatitis B virus infection.

AIM: We tested associations between HFE mutations and hepatitis B virus (HBV) infection. We also explored measures of total body iron status and their association with chronic HBV infection. METHODS: Serum measures of iron status and HFE mutations (C282Y, H63D, and S65C) were assessed in 344 Iranian patients with chronic HBV infection (214 asymptomatic carriers, 130 patients with chronic progressive liver disease [CPLD]) and 302 controls. RESULTS: Frequencies of HFE mutations did not differ between patients with chronic HBV infection and controls (C282Y: P=0.9, H63D: P= 0.8, S65C: P=0.9). By logistic regression, advanced hepatic fibrosis was associated with HFE H63D mutation (OR=13.1, P=0.006; 95% CI=2.0-84.1). Higher levels of serum ferritin and transferrin saturation were observed in patients with CPLD than in healthy controls (P=0.0001 and 0.01, respectively, adjusted for age and sex). None of the serum iron measures was related to liver fibrosis stage or necroinflammatory grade. CONCLUSION: Serum iron measures are associated with chronic progressive hepatitis B. Carriage of HFE mutations is not associated with the presence of chronic HBV infection or values of serum iron measures in this population, although HFE H63D is associated with more advanced hepatic fibrosis.