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Ex vivo embryonic liver explant culture is a novel and attractive approach to obtain abundant hepatic and hematopoietic stem cells. Gene therapy of autologous hepatic and hematopoietic stem cells represents an alternative therapeutic approach to liver transplantation for genetic and metabolic disorders. In this study we characterize the growth and differentiation of hepatic stem cells utilizing embryonic liver cultures. Day 9.5 liver buds are microdissected and cultured under specific conditions. Modulation of growth conditions by addition of hepatocyte growth factor, Flt-3 ligand, and stem cell factor leads to enrichment of hepatic progenitor cells in embryonic liver explants. Under these conditions, we also demonstrate the role of a novel marker PRAJA-1 to identify hepatic stem cells and transitional hepatocytes. Utilization of dexamethasone enhanced pseudolobule formation with increased hepatocytic and biliary differentiation. Transforming growth factor-β leads to enrichment of biliary cells in the culture. Gut formation is enhanced in the presence of interleukin-3 and blood formation by increasing the mesodermal tissue in these cultures. We also show increased retroviral-mediated expression of the green fluorescent protein expression in the expanded hepatic and hematopoietic stem cells under different culture conditions. Thus, the embryonic liver explant culture is an attractive source for hepatic progenitors and is a possible step towards generating nontumorigenic immortalized hepatocytes with possible transplantation applications.

BACKGROUND Scarce studies have addressed hematological differences of malaria in urban and rural regions. METHODS Full or complete blood cell counts from 46 and 75 individuals (age range from

BACKGROUND Cabazitaxel (Jevtana) has been approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC). However, most patients progress and become chemoresistant, which remains a major challenge in the management of advanced PCa. In this study, we investigated whether genistein, an isoflavone abundant in soy products, could sensitize mCRPC cells to cabazitaxel treatment in experimental models. METHODS The in vitro and in vivo effect of genistein in enhancing the response of mCRPC cells to cabazitaxel chemotherapy was evaluated in experimental models. RESULTS Genistein increases the expression of pro-apoptotic protein Bax, activates apoptotic signals, and enhances the response to cabazitaxel treatment in mCRPC cells. In a PC3-luciferase xenograft model, the combined treatment with genistein and cabazitaxel significantly retarded the growth of mCRPC when compared to vehicle control, cabazitaxel, or genistein. Tissue staining confirmed the in vivo effect of genistein on the induction of Bax and activation of apoptosis. CONCLUSION This study provided the first preclinical evidence supporting that genistein could be beneficial in improving cabazitaxel chemotherapy in mCRPC. Prostate 73: 1681–1689, 2013. © 2013 Wiley Periodicals, Inc.

Docetaxel treatment is the only first-line chemotherapy with a survival benefit in metastatic castration-resistant prostate cancer (PCa). Nonetheless, most patients become docetaxel resistant and inevitably progress with no cure. In this study, we investigated the potential of pomegranate extract (PE) in targeting metastatic castration-resistant PCa and improving docetaxel chemotherapy.The in vitro and in vivo effect of POMx, a PE formula currently approved for clinical trials, in metastatic castration-resistant PCa cells was evaluated in experimental models.We demonstrated that POMx exhibited potent in vitro cytotoxicity in metastatic castration-resistant PCa cells. Mechanistic studies identified survivin as a novel molecular target that may mediate the anti-cancer activity of POMx, presumably through the inhibition of signal transducer and activator of transcription 3. The in vivo administration of POMx treatment effectively inhibited survivin, induced apoptosis, retarded C4-2 tumor growth in skeleton and significantly enhanced the efficacy of docetaxel in athymic nude mice.These results provide the first preclinical evidence that POMx may be effective in treating metastatic castration-resistant PCa and enhancing the efficacy of docetaxel chemotherapy. Prostate © 2013 Wiley Periodicals, Inc.

Aberrant expression of EGF receptors has been associated with hormone-refractory and metastatic prostate cancer (PCa). However, the molecular mechanism for EGF signaling in promoting PCa metastasis remains elusive. Using experimental models of PCa metastasis, we demonstrated that EGF could induce robust epithelial-mesenchymal transition (EMT) and increase invasiveness. Interestingly, EGF was found to be capable of promoting protein turnover of epithelial protein lost in neoplasm (EPLIN), a putative suppressor of EMT and tumor metastasis. Mechanistic study revealed that EGF could activate the phosphorylation, ubiquitination, and degradation of EPLIN through an extracellular signal-regulated kinase 1/2 (ERK1/2)-dependent signaling cascade. Pharmacological inhibition of the ERK1/2 pathway effectively antagonized EGF-induced EPLIN degradation. Two serine residues, i.e. serine 362 and serine 604, were identified as putative ERK1/2 phosphorylation sites in human EPLIN, whose point mutation rendered resistance to EGF-induced protein turnover. This study elucidated a novel molecular mechanism for EGF regulation of EMT and invasiveness in PCa cells, indicating that blockade of EGF signaling could be beneficial in preventing and retarding PCa metastasis at early stages.

Background Aberrant platelet derived growth factor (PDGF) signaling has been associated with prostate cancer (PCa) progression. However, its role in the regulation of PCa cell growth and survival has not been well characterized. Methodology/Principal Findings Using experimental models that closely mimic clinical pathophysiology of PCa progression, we demonstrated that PDGF is a survival factor in PCa cells through upregulation of myeloid cell leukemia-1 (Mcl-1). PDGF treatment induced rapid nuclear translocation of β-catenin, presumably mediated by c-Abl and p68 signaling. Intriguingly, PDGF promoted formation of a nuclear transcriptional complex consisting of β-catenin and hypoxia-inducible factor (HIF)-1α, and its binding to Mcl-1 promoter. Deletion of a putative hypoxia response element (HRE) within the Mcl-1 promoter attenuated PDGF effects on Mcl-1 expression. Blockade of PDGF receptor (PDGFR) signaling with a pharmacological inhibitor AG-17 abrogated PDGF induction of Mcl-1, and induced apoptosis in metastatic PCa cells. Conclusions/Significance Our study elucidated a crucial survival mechanism in PCa cells, indicating that interruption of the PDGF-Mcl-1 survival signal may provide a novel strategy for treating PCa metastasis.

BackgroundMyeloid cell leukemia-1 (Mcl-1) is a member of the Bcl-2 family, which inhibits cell apoptosis by sequestering pro-apoptotic proteins Bim and Bid. Mcl-1 overexpression has been associated with progression in leukemia and some solid tumors including prostate cancer (PCa). However, the regulatory mechanism for Mcl-1 expression in PCa cells remains elusive.ResultsImmunohistochemical analyses revealed that Mcl-1 expression was elevated in PCa specimens with high Gleason grades and further significantly increased in bone metastasis, suggesting a pivotal role of Mcl-1 in PCa metastasis. We further found that vascular endothelial growth factor (VEGF) is a novel regulator of Mcl-1 expression in PCa cells. Inhibition of endogenous Mcl-1 induced apoptosis, indicating that Mcl-1 is an important survival factor in PCa cells. Neuropilin-1 (NRP1), the "co-receptor" for VEGF165isoform, was found to be highly expressed in PCa cells, and indispensible in the regulation of Mcl-1. Intriguingly, VEGF165promoted physical interaction between NRP1 and hepatocyte growth factor (HGF) receptor c-MET, and facilitated c-MET phosphorylationviaa NRP1-dependent mechanism. VEGF165induction of Mcl-1 may involve rapid activation of Src kinases and signal transducers and activators of transcription 3 (Stat3). Importantly, NRP1 overexpression and c-MET activation were positively associated with progression and bone metastasis in human PCa specimens and xenograft tissues.ConclusionsThis study demonstrated that Mcl-1 overexpression is associated with PCa bone metastasis. Activation of VEGF165-NRP1-c-MET signaling could confer PCa cells survival advantages by up-regulating Mcl-1, contributing to PCa progression.

Purpose: Survivin overexpression has been associated with an unfavorable outcome in human PCa; however, its role in metastasis remains elusive. We aim to (a) evaluate the clinical implications of survivin expression in PCa bone metastasis; (b) determine in vivo efficacy of BKM1740, a small-molecule compound, against PCa skeletal growth and survival; and (c) investigate molecular mechanism by which BKM1740 augments apoptosis in bone metastatic PCa cells. Experimental Design: Survivin expression was analyzed in PCa specimens and experimental models. Bone metastatic C4-2 and ARCaPM cell lines were used to evaluate the in vitro effects of BKM1740 and molecular mechanism for the induction of apoptosis. C4-2 cells were grown intratibially in athymic nude mice to evaluate the in vivo efficacy of BKM1740. Tumor growth in mouse bone was assessed by serum prostate-specific antigen and radiography and confirmed by immunohistochemical analyses. Results: Survivin expression is positively associated with clinical PCa bone metastasis. BKM1740 induced apoptosis in PCa cells by repressing survivin. Mice with established C4-2 tumors in tibia showed a marked decrease in serum prostate-specific antigen and much improved bone architecture radiographically after treatment with BKM1740. Immunohistochemical assays of mouse tumor samples confirmed that the in vivo effects were mediated by inhibition of survivin and induction of apoptosis. Conclusions: Survivin expression is associated with PCa bone metastasis. BKM1740 treatment specifically inhibited survivin and induced apoptosis in vitro and was efficacious in retarding PCa skeletal growth in a mouse model. BKM1740 is a promising small-molecule compound that could be used to treat PCa bone metastasis.

There is a growing movement to encourage reproducibility and transparency practices in the scientific community, including public access to raw data and protocols, the conduct of replication studies, systematic integration of evidence in systematic reviews, and the documentation of funding and potential conflicts of interest. In this survey, we assessed the current status of reproducibility and transparency addressing these indicators in a random sample of 441 biomedical journal articles published in 2000-2014. Only one study provided a full protocol and none made all raw data directly available. Replication studies were rare (n = 4), and only 16 studies had their data included in a subsequent systematic review or meta-analysis. The majority of studies did not mention anything about funding or conflicts of interest. The percentage of articles with no statement of conflict decreased substantially between 2000 and 2014 (94.4% in 2000 to 34.6% in 2014); the percentage of articles reporting statements of conflicts (0% in 2000, 15.4% in 2014) or no conflicts (5.6% in 2000, 50.0% in 2014) increased. Articles published in journals in the clinical medicine category versus other fields were almost twice as likely to not include any information on funding and to have private funding. This study provides baseline data to compare future progress in improving these indicators in the scientific literature.

Aberrant expression of vascular endothelial growth factor (VEGF) is associated with human prostate cancer (PCa) metastasis and poor clinical outcome. We found that both phosphorylation of cyclic AMP-responsive element-binding protein (CREB) and VEGF levels were significantly elevated in patient bone metastatic PCa specimens. A PCa ARCaP progression model demonstrating epithelial-to-mesenchymal transition exhibited increased CREB phosphorylation and VEGF expression as ARCaP cells became progressively more mesenchymal and bone-metastatic. Activation of CREB induced, whereas inhibition of CREB blocked, VEGF expression in ARCaP cells. CREB may regulate VEGF transcription via a hypoxia-inducible factor-dependent mechanism in normoxic conditions. Activation of CREB signaling is involved in the coordinated regulation of VEGF and may pre-dispose to PCa bone metastasis.

The influence of host genetics on susceptibility to Plasmodium falciparum malaria has been extensively studied over the past twenty years. It is now clear that malaria parasites have imposed strong selective forces on the human genome in endemic regions. Different genes have been identified that are associated with different malaria related phenotypes. Factors that promote severity of malaria include parasitaemia, parasite induced inflammation, anaemia and sequestration of parasitized erythrocytes in brain microvasculature. Recent advances in human genome research technologies such as genome-wide association studies (GWAS) and fine genotyping tools have enabled the discovery of several genetic polymorphisms and biomarkers that warrant further study in host-parasite interactions. This review describes and discusses human gene polymorphisms identified thus far that have been shown to be associated with susceptibility or resistance to P. falciparum malaria. Although some polymorphisms play significant roles in susceptibility to malaria, several findings are inconclusive and contradictory and must be considered with caution. The discovery of genetic markers associated with different malaria phenotypes will help elucidate the pathophysiology of malaria and enable development of interventions or cures. Diversity in human populations as well as environmental effects can influence the clinical heterogeneity of malaria, thus warranting further investigations with a goal of developing new interventions, therapies and better management against malaria.