This study characterized cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) cell lines, tumor specimens, and blood samples. The CD90+ cells, but not the CD90(-) cells, from HCC cell lines displayed tumorigenic capacity. All the tumor specimens and 91.6% of blood samples from liver cancer patients bore the CD45(-)CD90+ population, which could generate tumor nodules in immunodeficient mice. The CD90+CD44+ cells demonstrated a more aggressive phenotype than the CD90+CD44(-) counterpart and formed metastatic lesions in the lung of immunodeficient mice. CD44 blockade prevented the formation of local and metastatic tumor nodules by the CD90+ cells. Differential gene expression profiles were identified in the CD45(-)CD90+ and CD45(-)CD90(-) cells isolated from tissue and blood samples from liver cancer patients and controls.

This paper analyzes the prediction power of the economic policy uncertainty (EPU) index on the daily Bitcoin returns. Using the Bayesian Graphical Structural Vector Autoregressive model as well as the Ordinary Least Squares and the Quantile-on-Quantile Regression estimations, the paper finds that the EPU has a predictive power on Bitcoin returns. Fundamentally, Bitcoin returns are negatively associated with the EPU. However, the effect is positive and significant at both lower and higher quantiles of Bitcoin returns and the EPU. In the light of these findings, the paper concludes that Bitcoin can serve as a hedging tool against uncertainty.

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This study applies a set of measures developed by Diebold and Yilmaz (2012, 2016) to examine connectedness via return and volatility spillovers across six large cryptocurrencies from August 7, 2015 to February 22, 2018. Regardless of the sign of returns, the results show that Litecoin is at the centre of the connected network of returns, followed by the largest cryptocurrency, Bitcoin. This finding implies that return shocks arising from these two cryptocurrencies have the most effect on other cryptocurrencies. Further analysis shows that connectedness via negative returns is largely stronger than via positive ones. Ripple and Ethereum are the top recipients of negative-return shocks, whereas Ethereum and Dash exhibit very weak connectedness via positive returns. Regarding volatility spillovers, Bitcoin is the most influential, followed by Litecoin; Dash exhibits a very weak connectedness, suggesting its utility for hedging and diversification opportunities in the cryptocurrency market. Taken together, results imply that the importance of each cryptocurrency in return and volatility connectedness is not necessarily related to its market size. Further analyses reveal that trading volume and global financial and uncertainty effects as well as the investment-substitution effect are determinants of net directional spillovers. Interestingly, higher gold prices and US uncertainty increase the net directional negative-return spillovers, whereas they do the opposite for net directional positive-return spillovers. Furthermore, gold prices exhibit a negative sign for net directional-volatility spillovers, whereas US uncertainty shows a positive sign. Economic actors interested in the cryptocurrency market can build on our findings when weighing their decisions.

This paper introduces a growth model that considers the indicator of economic complexity as a measure of capabilities for exporting the high value-added (sophisticated) products. Empirically, the paper analyzes the effects of the renewable and the non-renewable energy consumption on the economic growth in the panel data of 29 Organization for Economic Cooperation and Development (OECD) countries for the period from 1990 to 2013. For this purpose, the paper considers the panel autoregressive distributed lag (ARDL) and the panel quantile regression (PQR) estimations. The paper finds that not only the economic complexity, but also both the non-renewable and the renewable energy consumption are positively associated with a higher rate of economic growth.

This paper investigates the predictive power of global geopolitical risks (GPR) index on daily returns and price volatility of Bitcoin over the period July 18, 2010-November 30, 2017. Considering a Bayesian Graphical Structural Vector Autoregressive (BSGVAR) technique, we find that GPR has a predictive power on both returns and price volatility of Bitcoin. The results of the Ordinary Least Squares (OLS) estimations show that price volatility and returns of Bitcoin are positively and negatively related to the GPR, respectively. However, findings from the Quantile-on-Quantile (QQ) estimations state that effects are positive at the higher quantiles of both the GPR as well as price volatility and returns of Bitcoin. Therefore, we conclude that Bitcoin can be considered as a hedging tool against global geopolitical risks.

This paper examines the causal relationship between Bitcoin attention (measured by the Google Trends search queries) and Bitcoin returns for the period from January 1, 2013, to December 31, 2017. For this purpose, we employ the Copula-Granger Causality in Distribution (CGCD) test. After implementing various robustness checks, we observe that there is a bi-directional causal relationship between Bitcoin attention and Bitcoin returns with the exception of the central distributions from 40% to 80%. To put it differently, the bidirectional causality mainly exists in the left tail (poor performance) and the right tail (superior performance) of the distribution.

Purpose: The goals of the present study were to investigate the mechanism of hypoxiamediated chemoresistance in liver cancer cells and tumorigenic hepatic progenitor (oval) cells and to determine whether disrupting an Akt/hypoxia-inducible factor-1α (HIF-1α)/platelet-derived growth factor (PDGF)-BB autocrine loop can enhance chemotherapeutic efficacy in hypoxia. Experimental Design: Five hepatocellular carcinoma (HCC) cell lines and two hepatic progenitor cell lines were treated in vitro with cisplatin under both normoxic and hypoxic conditions. To generate ischemic hypoxia for tumor cells in vivo, hepatic artery ligation was applied to an orthotopic HCC model. Cisplatin and YC1, which is a HIF-1α inhibitor, were administered by portal vein and intratumoral injections, respectively. Results: Cell viability was higher under hypoxic than normoxic conditions. HIF-1α and Akt were up-regulated under hypoxic conditions, forming an autocrine signaling loop with PDGF-BB. Akt/HIF-1α/PDGF-BB signaling regulated Akt to confer cisplatin resistance to HCC cell lines in vitro. This autocrine signaling loop also contributed to chemoresistance in the tumorigenic hepatic progenitor cell line PIL2 under hypoxic conditions but not in the nontumorigenic cell line PIL4. In an orthotopic HCC model, combining blockade of HIF-1α activity with ischemic hypoxia significantly enhanced the efficacy of chemotherapy, leading to suppression of tumor growth and prolongation of animal survival. Conclusion: Blockade of Akt/HIF-1α/PDGF-BB autocrine signaling could enhance the chemosensitivity of liver cancer cells and tumorigenic hepatic progenitor cells under hypoxic conditions and thus provide an effective therapeutic strategy for HCC.