More than 200 Chinese medicinal herb extracts were screened for antiviral activities against Severe Acute Respiratory Syndrome-associated coronavirus (SARS-CoV) using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay for virus-induced cytopathic effect (CPE). Four of these extracts showed moderate to potent antiviral activities against SARS-CoV with 50% effective concentration (EC50) ranging from 2.4 +/- 0.2 to 88.2 +/- 7.7 microg/ml. Out of the four, Lycoris radiata was most potent. To identify the active component, L. radiata extract was subjected to further fractionation, purification, and CPE/MTS assays. This process led to the identification of a single substance lycorine as an anti-SARS-CoV component with an EC50 value of 15.7 +/- 1.2 nM. This compound has a CC50 value of 14980.0 +/- 912.0 nM in cytotoxicity assay and a selective index (SI) greater than 900. The results suggested that four herbal extracts and the compound lycorine are candidates for the development of new anti-SARS-CoV drugs in the treatment of SARS.
Network pharmacology, based on the theory of systems biology, is a new discipline that analyzes the biological network and screens out the nodes of particular interest, with the aim of designing poly-target drug molecule. It emphasizes maximizing drug efficacy and minimizing adverse effect via the multiple regulation of the signaling pathway. Coincidentally, almost all traditional Chinese medicine (TCM) and worldwide ethnomedicine exert therapeutic effect by targeting multiple molecules of the human body. In this overview, we offer a critique on the present perception of TCM and network pharmacology; illustrate the utility of network pharmacology in the study of single herb, medicine pair, and TCM formula; and summarize the recent progress of TCM-based drug discovery inspired by network pharmacology. Network pharmacology could be of great help in decreasing drug attrition rate and thus is essential in rational and cost-effective drug development. We also pinpoint the current TCM issues that could be tackled by the flexible combined use of network pharmacology and relevant disciplines.
Purpose: Although microRNAs (miRNA) have been revealed as crucial modulators of tumorigenesis, our understanding of their roles in renal cell carcinoma (RCC) is limited. Here we sought to identify human miRNAs that act as key regulators of renal carcinogenesis.Experimental Design: We performed microarray-based miRNA profiling of clear cell RCC (ccRCC) and adjacent normal tissues and then explored the roles of miR-141 both in vitro and in vivo, which was the most significantly downregulated in ccRCC tissues.Results: A total of 74 miRNAs were dysregulated in ccRCC compared with normal tissues. miR-141 was remarkably downregulated in 92.6% (63/68) ccRCC tissues and would serve as a promising biomarker for discriminating ccRCC from normal tissues with an area under the receiver operating characteristics curve of 0.93. Overexpression of miR-141 robustly impaired ccRCC cell migratory and invasive properties and suppressed cell proliferation by arresting cells at G 0 -G 1 phase in vitro and in human RCC orthotopic xenografts. Significantly, the antitumor activities of miR-141 were mediated by its reversal regulation of erythropoietin-producing hepatocellular (Eph) A2 (EphA2), which then relayed a signaling transduction cascade to attenuate the functions of focal adhesion kinase (FAK), AKT, and MMP2/9.
We previously demonstrated that neurotensin (NTS) induces local inflammation and promotes tumor invasion in hepatocellular carcinoma (HCC). However, the underlying molecular mechanisms are not clear. In this study, positive correlations between NTS and interleukin (IL)-8 were identified at both the mRNA and protein levels in 71 fresh HCC tissues and 100 paraffin-embedded HCC tissues. Furthermore, significant correlations were determined among the co-expression of NTS and IL-8, infiltration of inflammatory cells and enhanced epithelial-mesenchymal transition (EMT) of HCC cells. NTS-induced IL-8 production was associated with activation of the mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways rather than the protein kinase C (PKC) and phosphoinositide-3 kinase (PI3K) pathways, whose specific antagonists significantly inhibited activation of the NTS/IL-8 pathway. IL-8, which promoted EMT and HCC invasion both and, was produced by NTS-induced HCC cells and was effectively attenuated by blocking IL-8 receptors . Moreover, HCC-derived IL-8 attracted more CD68 tumor-associated macrophages (TAMs) and CD66b polymorphonuclear neutrophils (PMNs) to the local microenvironment, displaying enhanced cytokine secretion and phagocytosis. IL-8 stimulated the M2 polarization of TAMs, which promoted the EMT and invasive potential of HCC cells. Blockage of the IL-8 receptor, NTR1 receptor or both significantly reduced HCC metastases in tumor-bearing mouse models via inhibiting EMT. In summary, aberrant activation of the NTS/IL-8 pathway in HCC dramatically stimulated the invasive potential of HCC cells. HCC-derived IL-8 promoted a pro-oncogenic inflammatory microenvironment by inducing M2-type TAMs and indirectly promoting EMT, which might be a valuable therapeutic target to prevent tumor progression.
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