Induction of apoptosis and inhibition of cell migration and tube-like formation by dihydroartemisinin in murine lymphatic endothelial cells.
ABSTRACT Dihydroartemisinin (DHA) is a semisynthesized agent from the artemisinin first extracted from the Chinese plant Artemisia annua. Previous studies have shown that artemisinin derivates, apart from their antimalarial activity, possess antitumor, antiangiogenic, and anti-inflammatory effects. In the present investigation, DHA was found to have a potent ability in influencing lymphatic endothelial cells (LECs) behavior. Murine LECs were isolated from benign lymphangiomas induced by intraperitoneal injection of incomplete Freund's adjuvant and identified by indirect immunofluorescence assay and fluorescence-activated cell sorting analysis to examine the expression of the specific marker VEGFR-3/Flt-4. When LECs were treated with DHA at 10 microg/ml, the growth of LECs was inhibited, and LECs showed typical apoptotic morphological features, with a higher apoptotic rate as compared with the controls. DHA also exerted a significant inhibitory effect on migration and tube-like formation of LECs in a dose-dependent manner. Quantitative RT-PCR further showed that DHA remarkably downregulated the expression of antiapoptotic bcl-2 mRNA, but upregulated that of the proapoptotic gene bax mRNA. In addition, DHA could strongly attenuate the mRNA and protein levels of VEGFR-3/Flt-4. In summary, these findings indicate that DHA may be useful as a potential lymphangiogenesis inhibitor under induction of cell apoptosis, inhibition of the migration, and formation of tube-like structures in LECs.
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ABSTRACT: Lymphangiogenesis is actively contributed to lymphatic metastasis in gastric cancer (GC), and vascular endothelial growth factor (VEGF)-C and VEGF-D are key regulators for lymphangiogenesis. Metastasis-associated in colon cancer-1 (MACC1) was reported to be associated with lymph node metastasis in a few clinical studies, while little is known about the role of MACC1 in lymphangiogenesis. Hence, in the present study, we explored the potential role of MACC1 in lymphangiogenesis as well as the underlying mechanisms. By clinical observation, we found a positive relationship between MACC1 and lymphangiogenesis. Besides, a similar result was also obtained from in vivo and in vitro studies. With an indirect co-culture system, we got that supernatant from MACC1 overexpressed GC cells accelerated human lymphatic endothelial cells' (HLECs') capacity of tube-like formation through enhancing cell proliferation and migration. Moreover, MACC1 overexpressed xenografts also presented more lymphatic vessels. Furthermore, MACC1 significantly increased the expression of VEGF-C/VEGF-D in GC cells and transplanted tumors, which was subsequently suppressed by c-Met inhibitor. All these data suggested a critical role for MACC1 in lymphatic dissemination of GC, providing evidence that MACC1 upregulated VEGF-C/VEGF-D secretion to promote lymphangiogenesis via c-Met signaling. Copyright © 2014. Published by Elsevier Ireland Ltd.Cancer Letters 11/2014; 357(1). DOI:10.1016/j.canlet.2014.11.035 · 5.02 Impact Factor
Antimicrobial Agents and Chemotherapy 06/2012; 56(9):4594. · 4.45 Impact Factor
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ABSTRACT: Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has been demonstrated to possess a strong antiangiogenic activity. However, the molecular mechanisms underlying this effect remain unclear. Endothelial cell (EC) migration is an essential component of angiogenesis, and the p38 mitogen-activated protein kinase (MAPK) signaling pathway plays a key role in the regulation of migration induced by vascular endothelial growth factor (VEGF). The aim of the present study was to investigate the effects of DHA on EC migration and the p38 MAPK signaling pathway. Human umbilical vein ECs (HUVECs) were treated with DHA and VEGF-induced migration was analyzed. The activation of p38 MAPK was detected by western blot analysis, and the migration assays were performed with a p38-specific inhibitor, SB203850. It was revealed that 20 μM DHA significantly reduced EC migration in the transwell migration assay, wound healing assay and electrical cell-substrate impedance sensing real-time analysis. However, DHA did not affect p38 MAPK phosphorylation or expression. In the absence or presence of SB203850, DHA induced a similar proportional reduction of EC migration in the three migration assays. Therefore, the present study demonstrated that DHA inhibits VEGF-induced EC migration via a p38 MAPK-independent pathway.Experimental and therapeutic medicine 12/2014; 8(6):1707-1712. DOI:10.3892/etm.2014.1997 · 0.94 Impact Factor