Growth inhibitory activity of lemnabourside on human prostate cancer cells

Induction of apoptosis and androgen ablation are two major approaches for treating human prostate carcinoma. In a study of the bioactive components of the soft coral Nephthea chabroli, we found that lemnabourside is a 5alpha-reductase inhibitor, as shown by its ability to inhibit the conversion of testosterone into the more potent dihydrotestosterone in rat prostate homogenate. The compound also inhibited the incorporation of tritiated thymidine into human prostate androgen-dependent carcinoma LNCaP cells, and thus blocking the cell proliferation IC50 = 37.5 muM). The expression of prostate marker genes, including 5a-reductase, prostate-specific antigen, prostatic acid phosphatase and androgen receptor, and the anti-apoptotic bcl-2 gene were markedly reduced, but the transcription of apoptosis-related caspase 3 gene showed a dose-dependent increase in lemnabourside-treated LNCaP cells. Immunofluorescent microscopy and flow cytometric analysis further demonstrated apoptotic changes in these cells. Taken all results together, a relatively weak 5(x-reductase inhibitory activity on LNCaP cells (EC50 > 250 muM), and a similar growth inhibitory activity on both androgen dependent- and independent-prostate cells (IC50 approximate to 37.5 muM) indicated that caspase-3 apoptosis pathway is one of the possible antiproliferative activities mediated by lemnabourside. (C) 2002 Elsevier Science Inc. All rights reserved

Comparison of protein expression patterns between hepatocellular carcinoma cell lines and a hepatoblastoma cell line

Hepatocellular carcinoma (HCC) and hepatoblastoma (HB) are malignancies of the liver with different etiologies, but the HB cell line HepG2 has been frequently used in various studies of HCC. In this study, we compare the protein expression patterns between HepG2 cells and three HCC cell lines, HKCI-2, HKCI-3, and HKCI-4, respectively. The cell lysates of individual cell lines were separated by two-dimensional polyacrylamide gel electrophoresis. The protein spots in the gel images were quantified and compared by image analysis software. The differentially expressing proteins were then identified by tryptic peptide mass fingerprinting. Compared with the HepG2 cells, the normalized quantities of 49 and 58 protein spots were found to be at least twofold higher and twofold lower, respectively, in all three HCC cell lines. The differentially expressed proteins can be grouped into structural proteins (annexins, transgelin, laminin receptor), stress-induced proteins (HSP27, 60, and 70), enzymes (aldehyde dehydrogenase, pyruvate kinase, α-enolase, etc.), and transcription factors (far upstream element binding protein 2, GTP-binding nuclear protein RAN). Some of these proteins play important roles in regulating homeostasis, drug resistance, apoptosis, cell differentiation, cell growth, and metastasis. In conclusion, our proteomic data indicate that there are considerable differences in the protein expression patterns between HepG2 cells and the HCC cells, suggesting differences m cellular properties. Hence, HepG2 may not be a good cell line model for studying HCC. Copyright © Humana Press Inc. All rights of any nature whatsoever are reserved.link_to_subscribed_fulltex

Reversal of endothelial progenitor cell dysfunction in patients with type 2 diabetes using a conditioned medium of human embryonic stem cell-derived endothelial cells

Background: The potential clinical application of bone marrow or peripheral blood-derived progenitor cells for cardiovascular regeneration in patients with diabetes mellitus (DM) is limited by their functional impairment. We sought to determine the mechanisms of impaired therapeutic efficacy of peripheral blood-derived progenitor cells in type 2 DM patients and evaluated the use of cell-free conditioned medium obtained from human embryonic stem cell-derived endothelial-like cells (ESC-ECs) to reverse their functional impairment. Methods: The angiogenic potential of late outgrowth endothelial cells (OECs) and cytokine profile of the conditional medium of proangiogenic cells (PACs) derived from peripheral blood-mononuclear cells of healthy control and DM patients and ESC-ECs was compared by in vitro tube formation assay and a multiplex bead-based immunoassay kit, respectively. The in vivo angiogenic potential of ESC-ECs derived conditioned medium in rescuing the functional impairment of PB-PACs in DM patients was investigated using a hindlimb ischemia model. Results: Human ESC-ECs had similar functional and phenotypic characteristics as OECs in healthy controls. Cytokine profiling showed that vascular endothelial growth factor, stromal cell-derived factor 1 and placental growth factor were down-regulated in PACs from DM patients. Tube formation assay that revealed functional impairment of OECs from DM patients could be rescued by ESC-ECs conditioned medium. Administration of ESC-ECs conditioned medium restored the therapeutic efficacy of PB-PACs from DM patients in a mouse model of hindlimb ischemia. Conclusions: Our results showed that peripheral blood-derived progenitor cells from DM patients have impaired function because of defective secretion of angiogenic cytokines, which could be restored by supplementation of ESC-ECs conditioned medium. © 2012 John Wiley & Sons, Ltd.link_to_subscribed_fulltex