BackgroundAlthough expression of MTA1 inversely correlates with the nuclear localization of ERα, the effect and molecular mechanism of ERα regulation of MTA1 remain unknown.MethodsQuantitative real-time PCR and western blot analyses were used to measure levels of MTA1. The effect on HCC cell proliferation and invasion was assessed by EdU incorporation assays and Transwell, respectively. ShRNA and dual-luciferase assays were used to investigate the regulatory relationship between MTA1 and ERα in cell lines.ResultsWe found that MTA1 gene regulation by ERα may be influenced by nuclear corepressors. The MTA1 promoter has three functional ER-element half-sites that lead to decreased MTA1 transcription and expression. ERα overexpression suppressed the proliferation and invasion of hepatocellular carcinoma cells (HCC). In addition, overexpression of MTA1 attenuated ERα-mediated suppression of the proliferation and invasion of HCC cells and tumor formation in vivo. These results suggested feedback regulation between ERα and MTA1. In summary, our results demonstrated that ERα suppressed proliferation and invasion of human HCC cells through downregulation of MTA1 transcription.ConclusionsOur study is an improved description of the mechanisms of the suppressive effect of ERα on HCCs, adding understanding to the gender disparity of HCC progression.

Acute rejection is commonly encountered for long-term survival in liver transplant (LT) recipients and may impact their long-term survival if rejection is severe or recurrent. The aim of this study is to examine the therapeutic potential of transforming growth factor (TGF-b)-overexpressing mesenchymal stem cells (MSCs) in inducing a local immunosuppression in liver grafts after transplantation. MSCs were transduced with a lentiviral vector expressing the human TGF-b1 gene; TGF-b1-overexpressing MSCs (designated as TGF/MSCs) were then transfused into the liver grafts via the portal vein of a rat LT model of acute rejection. Rejection severity was assessed by clinical and histologic analysis. The immunity suppression effects and mechanism of TGF/ MSCs were tested, focusing on their ability to induce generation of regulatory T cells (Tregs) in the liver grafts. Our findings demonstrate that transfusion of TGF/MSCs prevented rejection, reduced mortality, and improved survival of rats after LT. The therapeutic effects were associated with the immunosuppressive effects of MSCs and TGF-b1. Their reciprocal effects on Tregs induction and function resulted in more CD4 1 Foxp3 1 Helios-induced Tregs, fewer Th17 cells, and improved immunosuppressive effects in local liver grafts. Thus, TGF/MSCs can induce a local immunosuppressive effect in liver grafts after transplantation. The immunomodulatory activity of TGF-b1 modified MSCs may be a gateway to new therapeutic approaches to prevent organ rejection in clinical transplantation. STEM CELLS 2016;34:2681-2692 SIGNIFICANCE STATEMENTAcute rejection is commonly encountered for long-term survival in liver transplant recipients. Despite great improvements in systemic immunosuppressive agents, complications related to the administration of immunosuppressive therapy remain a predominant cause of posttransplantation morbidity and mortality. Thus, local and alloantigen specific immunological tolerance may be a promising approach to improved organ transplantation. Regulatory T cells (Tregs) are available to enforce graft to function as alternative immunosuppressive therapy possibly with less side effects. mesenchymal stem cells can induce the generation of Tregs, and transforming growth factor (TGF)-b enhance the induction. Our study demonstrated that systemic administration of TGF/MSCs induced a local and highly efficient suppression by producing more induced Tregs in the local liver grafts.

In this study, the antitumor consequences of using B7-1, B7-2 and 4-1BBL gene transfer have demonstrated the therapeutic potential of gene therapy approach for hepatocellular carcinoma.

BackgroundChronic hepatitis B virus (HBV) infection is an important cause of cirrhosis and hepatocellular carcinoma. The major challenges for current therapies are the low efficacy of current drugs and the occurrence of drug resistant HBV mutations. RNA interference (RNAi) of virus-specific genes offers the possibility of developing a new anti-HBV therapy. Recent reports have shown that lentiviral vectors based on HIV-1 are promising gene delivery vehicles due to their ability to integrate transgenes into non-dividing cells. Herein, a lentivirus-based RNAi system was developed to drive expression and delivery of HBV-specific short hairpin RNA (shRNA) in a mouse model for HBV replication.MethodsHepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in the sera of the mice were analyzed by quantitative sandwich enzyme linked immunosorbent assay (ELISA) technique, hepatitis B core antigen (HBcAg) and HBsAg in the livers of the mice were detected by immunohistochemical assay, HBV DNA and HBV mRNA were measured by fluorogenic quantitative polymerase chain reaction (FQ-PCR) and quantitative real-time PCR respectively.ResultsCo-injection of HBV plasmids together with the lentivirus targeting HBV shRNA induced an RNAi response. Secreted HBsAg was reduced by 89% in mouse serum, and HBeAg was also significantly inhibited, immunohistochemical detection of HBcAg or HBsAg in the liver tissues also revealed substantial reduction. Lentiviral mediated shRNA caused a significant suppression in the levels of viral mRNA and DNA synthesis compared to the control group.ConclusionLentivirus-based RNAi can be used to suppress HBV replication in vivo, it might become a potential therapeutic strategy for treating HBV and other viral infections.

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The branched‐chain amino‐acid aminotransferase from Streptococcus mutans (SmIlvE) was recombinantly expressed in Escherichia coli with high yield. An effective purification protocol was established. A bioactivity assay indicated that SmIlvE had aminotransferase activity. The specific activity of SmIlvE towards amino‐acid substrates was found to be as follows (in descending order): Ile > Leu > Val > Trp > Gly. The protein was crystallized using the hanging‐drop vapour‐diffusion method with PEG 3350 as the primary precipitant. The structure of SmIlvE was solved at 1.97 Å resolution by the molecular‐replacement method. Comparison with structures of homologous proteins enabled the identification of conserved structural elements that might play a role in substrate binding. Further work is needed to confirm the interaction between SmIlvE and its substrates by determining the structures of their complexes.

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