No abstract

A considerable amount of research has focused on the roles of microRNAs (miRNA) in the pathophysiology of liver fibrosis in view of their regulatory effects on hepatic stellate cell (HSC) functions, including proliferation, differentiation, and apoptosis. Recently, miR-17-5p was shown to promote cell proliferation and migration in liver. Transforming growth factor-β1 (TGF-β1) has been characterized as the master fibrogenic cytokine that stimulates HSC activation and promotes progression of liver fibrosis. The issue of whether miR-17-5p plays a role in TGF-β1-induced hepatic fibrogenesis remains to be established. In this study, we demonstrated a dose-/time-dependent increase in miR-17-5p expression in TGF-β1-treated HSCs. Enhanced miR-17-5p expression was additionally observed in CCl 4 -induced rat liver fibrosis. Inhibition of miR-17-5p led to suppression of HSC proliferation induced by TGF-β1 without affecting cellular apoptosis. Notably, miR-17-5p was significantly associated with TGF-β1-induced expression of type I collagen and α-SMA in HSC. Furthermore, Smad7, a negative regulator of the TGF-β/Smad pathway, was confirmed as a direct target of miR-17-5p. Serum miR-17-5p levels were significantly higher in patients with cirrhosis, compared to healthy controls. Our results collectively indicate that miR-17-5p promotes HSC proliferation and activation, at least in part, via reduction of Smad7, supporting its potential utility as a novel therapeutic target for liver fibrosis.

Ribosomal protein s15a (RPS15A) plays a promotive role in the mRNA/ribosome interactions during early translation. Our previous study has found that inhibiting RPS15A expression can decrease proliferation and induce cell cycle arrest in hepatocellular carcinoma (HCC) cell lines. However, the mechanism underlying the involvement of RPS15A in HCC pathogenesis and the clinical significance of RPS15A expression remain unclear. In this study, an evaluation of RPS15A expression in 110 surgically resected HCCs and matched tumor-adjacent normal tissues revealed an overexpression of RPS15A in HCC, which was correlated with worse survival. In addition, tumor tissue with higher RPS15A expression demonstrated a higher microvascular density (MVD). Subsequently, two HCC cell lines, Huh7 (low-level constitutive RPS15A expression) and HepG2 (high RPS15A expression) were used to further evaluate the role of RPS15A in angiogenesis. The co-culture experiment of HCC cells with endothelial cells revealed that the induced overexpression of RPS15A in Huh7 cells increased the angiogenic potential of HUVEC in a paracrine fashion; conversely, knockdown of RPS15A in HepG2 cells showed an opposite effect. Further analysis indicated that RPS15A modulated FGF signaling by enhancing Wnt/beta-catenin-mediated FGF18 expression in HCC cells. FGF18, in turn, through binding to its FGFR3 receptor on endothelial cells, can activate the AKT and ERK pathway and promotes angiogenesis in a tumor microenvironment. Our in vivo experiment further confirmed that inhibition of RPS15A expression in HCC xenografts dramatically hindered tumor growth and inhibited tumor angiogenesis. Together, our findings suggest that RPS15A promotes angiogenesis in HCCs by enhancing Wnt/beta-catenin induced FGF18 expression. The RPS15A/FGF18 pathway may be a rational target for anti-angiogenic therapy of HCC.

Development of novel targeted therapy holds promise for conquering chemotherapy resistance, one of major hurdles in current liver cancer treatment. We found that long non-coding RNA TUC338 is involved in the development of hepatocellular carcinoma (HCC) and sorafenib resistance. HCC cell lines were transfected with siTUC338, then cell proliferation and invasion ability were investigated by MTT and Transwell assay. Sorafenib resistance HepG2 cells were generated to test the role of TUC338 in sorafenib sensitivity. Intratumoral delivering of siTUC338 was used to analyze the sorafenib treatment response in HepG2/Sor xenografts in vivo. Higher levels of TUC338 were found both in HCC tissues and cell lines, knockdown of TUC338 was accompanied with increased expression of RASAL1 in HCC cell line with increased proliferation and invasion ability, knockdown of TUC338 could activate the RASAL1 pathway and inhibit tumor growth genes by directly targeting RASAL1 3'-UTR. Furthermore, knockdown of TUC338 in HepG2 sorafenib sensitized its reaction to the treatment of sorafenib, which was accompanied by increased expression RASAL1; intratumoral delivering of siTUC338 could also restore sorafenib treatment response in HepG2/Sor xenografts in vivo. These findings provide direct evidence that the TUC338/RASAL1 axis might play an essential role in sorafenib-resistance of liver cancer cells, suggesting the signaling cohort could serve as a novel therapeutic target for the treatment of chemotherapy resistant liver cancer.

ADSCs inhibit the proliferation and activation of HSCs in vitro and inhibit liver fibrogenesis in rat model, suggesting the potential application of ADSCs in liver fibrogenesis therapy.

BackgroundEndothelial progenitor cells (EPCs) can migrate to the tumor tissue and enhance the angiogenesis of hepatocellular carcinoma (HCC); thus, they are associated with a poor prognosis. However, the specific molecular mechanism underlying the homing of EPCs to the HCC neovasculature remains unrevealed.MethodsCo-culture experiments of endothelial progenitor cells with HCC cells with modulation of EphA1 were performed in vitro. Using EPCs as angiogenic promoters by injecting them into HCC xenograft-bearing nude mice via their tail veins to test homing ability of EPCs changed according to different EphA1 level in HCC xenograft.ResultsIn this study, we found that the up-regulation of EphA1 expression in HCC cells could affect not only the chemotaxis of EPCs to tumor cells and endothelial cells (ECs) but also the tube formation ability of EPCs in a paracrine fashion. Further, we revealed that the increased expression of EphA1 in HCC cells led to an increased SDF-1 concentration in the tumor microenvironment, which in turn activated the SDF-1/CXCR4 axis and enhanced the recruitment of EPCs to HCC. In addition, the EphA1-activated SDF-1 expression and secretion was partially mediated by the PI3K and mTOR pathways. In vivo experiments demonstrated that blocking EphA1/SDF-1/CXCR4 signaling significantly inhibited the growth of HCC xenografts. Using immunohistochemistry and immunofluorescence assays, we verified that the inhibition of tumor angiogenesis was at least partially caused by the decreased number of EPCs homing to tumor tissue.ConclusionsOur findings indicate that targeting the EphA1/SDF-1 signaling pathway might be a therapeutic anti-angiogenesis approach for treating HCC.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-016-0339-6) contains supplementary material, which is available to authorized users.

Our initial experience showed that combined CT-guided (125)I radioactive seed implantation and GP chemotherapy are effective and safe for treating advanced NCSLC.

Mesenchymal stem cell (MSC) therapy has emerged as a potential novel method of treating liver fibrosis. To date, bone marrow-derived MSCs (BM-MSCs) and adipose tissue-derived MSCs (AD-MSCs) have not been analyzed with respect to their ability to combat liver fibrosis. The present study aimed to compare the capabilities of BM-MSCs and AD-MSCs in the treatment of liver fibrosis. BM-MSCs and AD-MSCs were taken from male Sprague-Dawley rats and cultured. Hepatic stellate cells (HSCs) were co-cultured with either BM-MSCs or AD-MSCs, and the effects of BM-MSCs or AD-MSCs on the proliferation, activation and apoptosis of HSCs were determined. The secretion of a selected group of cytokines by BM-MSCs and AD-MSCs was measured using enzyme-linked immunosorbent assays. Using a CCl4-induced liver fibrosis animal model, the anti-inflammatory and anti-fibrotic effects of BM-MSCs or AD-MSCs against liver fibrosis in vivo were evaluated. The morphological examination and analysis of specific surface markers confirmed the successful preparation of BM-MSCs and AD-MSCs. Furthermore, the proliferation, activation and apoptosis of HSCs were significantly inhibited by BM-MSCs and AD-MSCs, with statistically greater reductions achieved by AD-MSCs compared with BM-MSCs. Direct comparison of the secretion of selected cytokines by BM-MSCs and AD-MSCs revealed that significantly higher levels of nerve growth factor and transforming growth factor-β1 were secreted in the AD-MSC culture medium, whereas levels of vascular endothelial growth factor and interleukin-10 did not differ significantly between AD-MSCs and BM-MSCs. In vivo studies using a CCl4-induced liver fibrosis model demonstrated that inflammatory activity and fibrosis staging scores were significantly lower in the MSC-treated groups compared with controls. Although AD-MSCs improved anti-inflammatory and anti-fibrotic effects compared with BM-MSCs, these differences were not significant. Thus, the current study demonstrated that BM-MSCs and AD-MSCs are similarly effective at attenuating liver fibrosis by inhibiting the activation and proliferation of HSCs, as well as promoting the apoptosis of HSCs.