The role of HMGB1-RAGE axis in migration and invasion of hepatocellular carcinoma cell lines.

High mobility group protein box1 (HMGB1) and its receptor-receptor for advanced glycation end products (RAGE) are pivotal factors in the development and progression of many types of tumor, but the role of HMGB1-RAGE axis in hepatocellular carcinoma (HCC) especially its effects on metastasis and recurrence remains obscure. Here, we report the role of HMGB1-RAGE axis in the biological behaviors of HCC cell lines and the underlying molecular mechanism. We show that the expressions of HMGB1, RAGE, and extracellular HMGB1 increase consistently according to cell metastasis potentials, while the concentration of soluble form of RAGE (sRAGE) is inversely related to metastasis potential of HCC cells. Furthermore, our data show that rhHMGB1 promotes cellular proliferation, migration, and invasion, and increases the level of nuclear factor kappa B (NF-κB), while administrations of HMGB1-siRNA, RAGE-siRNA, anti-HMGB1 neutralizing antibody, anti-RAGE neutralizing antibody, and sRAGE inhibit cellular proliferation, migration, and invasion. Moreover, we also demonstrate that the expression of NF-кB is inhibited by knockdown of HMGB1 or RAGE. Collectively, these data demonstrate that HMGB1 activates RAGE signaling pathways and induces NF-кB activation to promote cellular proliferation, invasion, and metastasis, in HCC cell lines. Taken together, HMGB1-RAGE axis may become a potential target in HCC therapy.

Comparison of methods of isolating extracellular vesicle microRNA from HepG2 cells for High-throughput sequencing.

Background: Extracellular vesicles (EVs) were reported to participate in various cellular processes based on the biomolecules, particularly microRNAs. Numerous commercial EVs isolation reagents are available. However, whether these reagents are suitable for separating EVs from the culture medium supernatant supernatant of model cell lines, such as HepG2, and whether the isolated products are suitable for High-throughput sequencing remains unclear. Methods: We examined three commonly used EVs isolation kits: the ExoQuick-TC exosome precipitation solution (EQ), Total Exosome Isolation from cell culture medium (EI), and exoEasy Maxi Kit (EM), to isolate EVs from HepG2 cell culture medium supernatants. EVs were identified based on marker proteins, particle size measurements, and electron microscopy analysis. The total amounts of microRNA and microRNA High-throughput sequencing data quality from EVs isolated by each kit were compared. Results: The total amount of EVs' microRNA isolated from the EI and EM groups were higher than that obtained from the EQ group (EQ/EI: p = 0.036, EI/EM: p = 0.024). High-throughput sequencing data quality evaluation showed that the EI group possessed higher quality than those in the EM group. Conclusion: For the cell culture medium from HepG2, EVs' microRNA isolated by EI reagents might be more suitable for High-throughput sequencing applications.

Comparison of the efficacy of Lamivudine plus adefovir versus entecavir in the treatment of Lamivudine-resistant chronic hepatitis B: a systematic review and meta-analysis.

BACKGROUND: Hepatitis B virus infection remains 1 of the major health threats worldwide. Currently, lamivudine plus adefovir combination therapy or entecavir monotherapy is usually used for the treatment of patients with lamivudine-resistant chronic hepatitis B (CHB). However, there are few systematic comparisons between the efficacy of lamivudine plus adefovir and the efficacy of entecavir in the treatment of these patients. OBJECTIVE: The goal of this systematic study and meta-analysis was to assess the efficacy of lamivudine plus adefovir compared with entecavir for the treatment of patients with lamivudine-resistant CHB. METHODS: A comprehensive literature search of PUBMED, Web of Science, WANFANG database, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Review, were screened to obtain citations from January 1990 to January 2012 in this study. Data analysis was done by using the Review Manager Software 5.1. RESULTS: Eight studies were suitable for analysis. A total of 696 patients with lamivudine-resistant CHB were studied and grouped according to treatment: 341 patients in the entecavir group and 355 patients in the lamivudine plus adefovir group. The results found that the rates of undetectable hepatitis B virus DNA levels, alanine aminotransferase normalization, hepatitis B e antigen loss, and hepatitis B e antigen seroconversion were not significantly different between the lamivudine plus adefovir group and the entecavir group. Moreover, the rate of adverse reactions was also not significantly different between the 2 groups. However, virologic breakthrough for the patients with lamivudine resistance was higher in the entecavir group than in the lamivudine plus adefovir group. CONCLUSIONS: For these CHB patients with lamivudine resistance, lamivudine plus adefovir was a better treatment option than entecavir alone.

HMGB1 release by human liver L02 and HepG2 cells induced by lipopolysaccharide.

Liver cells release the high mobility group box-1 (HMGB1) protein when exposed to lipopolysaccharides (LPSs). However, the timing and levels of protein released remain unclear. The present study aimed to characterize the secretion of the late pro-inflammatory cytokine HMGB1 by liver L02 and HepG2 cells. The human mononuclear macrophage cell line U937 was used as a control. Various concentrations of LPS were added to human U937, L02 and HepG2 cells for different durations, and the cells were analyzed at different time-points following this addition. Reverse transcription polymerase chain reaction (RT-PCR) was used to measure cellular HMGB1 mRNA levels, western blotting was performed to detect HMGB1 in cellular supernatants and the translocation of HMGB1 from the nucleus to the cytosol was examined using immunofluorescence staining. L02 and HepG2 cells exhibited higher HMGB1 mRNA levels compared with the control U937 cells 20 and 24 h following continuous exposure to LPS. U937 cells exhibited higher HMGB1 mRNA levels compared with the corresponding L02 and HepG2 cells 16 h following LPS exposure. The phase of HMGB1 protein detected in the cellular supernatants of L02 and HepG2 cells (16 h) was later than that of U937 cells (8 h). For the three cell lines, HMGB1 levels demonstrated a time dependency; however, the protein level was the highest in U937 cells. In the three cell lines, translocation of HMGB1 from the nucleus to the cytosol occurred; however, the phases of HMGB1 translocation in L02 and HepG2 cells occurred later than in U937 cells. LPS-induced secretion of the late pro­inflammatory cytokine HMGB1 by liver cells is characterized by a late phase of release and smaller quantity, and the process of HMGB1 secretion appears to be associated with HMGB1 translocation.