Dilu Feng

Universität des Saarlandes, Saarbrücken, Saarland, Germany

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Publications (7)22.68 Total impact

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    ABSTRACT: In endometriosis research, endometriosis-like lesions are usually induced in rodents by transplantation of isolated endometrial tissue fragments to ectopic sites. In the present study, we investigated whether this approach is affected by the cellular composition of the grafts. For this purpose, endometrial tissue fragments covered with luminal epithelium (LE(+)) and without luminal epithelium (LE(-)) were transplanted from transgenic green fluorescent protein-positive (GFP(+)) donor mice into the dorsal skinfold chamber of GFP(-) wild-type recipient animals to analyze their vascularization, growth and morphology by means of repetitive intravital fluorescence microscopy, histology and immunohistochemistry during a 14-day observation period. LE(-) fragments developed into typical endometriosis-like lesions with cyst-like dilated endometrial glands and a well vascularized endometrial stroma. In contrast, LE(+) fragments exhibited a polypoid morphology and a significantly reduced blood perfusion after engraftment, because the luminal epithelium prevented the vascular interconnection with the microvasculature of the surrounding host tissue. This was associated with a markedly decreased growth rate of LE(+) lesions when compared to LE(-) lesions. Besides, we found that many GFP(+) microvessels grew outside the LE(-) lesions and developed interconnections to the host microvasculature, indicating that inosculation is an important mechanism in the vascularization process of endometriosis-like lesions. Our findings demonstrate that the luminal epithelium crucially affects the vascularization, growth and morphology of endometriosis-like lesions. Therefore, it is of major importance to standardize the cellular composition of endometrial grafts in order to increase the validity and reliability of pre-clinical rodent studies in endometriosis research.
    Preview · Article · Nov 2013 · Disease Models and Mechanisms
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    ABSTRACT: To study the effect of combretastatin A4 phosphate (CA4P) on the vascularization of endometriotic lesions. Intravital microscopic, histologic, and immunohistochemical study. University institute. BALB/c mice. Murine endometriotic lesions were induced by syngeneic transplantation of endometrium into dorsal skinfold chambers. After 6 days, the mice received an intraperitoneal injection of 80 mg/kg CA4P or vehicle. Vascularization of the lesions and the surrounding tissue was analyzed by intravital fluorescence microscopy over 8 days. Lesion morphology, vessel maturation, viability, and proliferation of endometrial glands and stroma were assessed by histology and immunohistochemistry. All lesions were initially well vascularized, containing immature and mature microvessels. Injection of CA4P induced a selective vessel collapse in the lesions without affecting the surrounding microvasculature. This resulted in a decreased functional capillary density and blood perfusion of CA4P-treated lesions after 2 hours when compared with controls. However, the vascularization of the lesions progressively normalized, and their numbers of proliferating and apoptotic cells did not differ from those of controls. This study demonstrates a selective vascular disrupting effect of CA4P on endometriotic lesions, indicating that vascular disrupting agents may be suitable for endometriosis therapy.
    No preview · Article · Aug 2013 · Fertility and sterility
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    ABSTRACT: Arctigenin, a functional ingredient of several traditional Chinese herbs, has been reported to have potential antitumor activity. However, its mechanisms of action are still not well elucidated. Because the establishment and metastatic spread of tumors is crucially dependent on angiogenesis, here we investigated whether arctigenin inhibits tumor growth by disturbing blood vessel formation. For this purpose, human dermal microvascular endothelial cells were exposed to different arctigenin doses to study their viability, proliferation, protein expression, migration, and tube formation compared with vehicle-treated controls. In addition, arctigenin action on vascular sprouting was analyzed in an aortic ring assay. Furthermore, we studied direct arctigenin effects on CT26.WT colon carcinoma cells. Spheroids of these tumor cells were transplanted into the dorsal skinfold chamber of arctigenin-treated and vehicle-treated BALB/c mice for the in-vivo analysis of tumor vascularization and growth by intravital fluorescence microscopy, histology, and immunohistochemistry. We found that noncytotoxic doses of arctigenin dose dependently reduced the proliferation of human dermal microvascular endothelial cells without affecting their migratory and tube-forming capacity. Arctigenin treatment also resulted in a decreased cellular expression of phosphorylated serine/threonine protein kinase AKT, vascular endothelial growth factor receptor 2, and proliferating cell nuclear antigen and inhibited vascular sprouting from aortic rings. In addition, proliferation, but not secretion of vascular endothelial growth factor, was decreased in arctigenin-treated tumor cells. Finally, arctigenin suppressed the vascularization and growth of engrafting CT26.WT tumors in the dorsal skinfold chamber model. Taken together, these results show for the first time an antiangiogenic action of arctigenin, which may contribute considerably toward its antitumor activity.
    No preview · Article · Jun 2013 · Anti-cancer drugs
  • Hongbo Wang · Dilu Feng · Barry Behr

    No preview · Article · Mar 2012
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    ABSTRACT: Endometriosis is a frequent gynecological disease, which is crucially dependent on the process of angiogenesis. However, the underlying regulatory mechanisms of blood vessel development are still poorly understood. CK2 is a pleiotropic protein kinase, which is implicated in the regulation of various cellular processes including angiogenesis. Herein we studied for the first time the function of protein kinase CK2 in angiogenesis of endometriotic lesions. For this purpose, we analyzed the anti-angiogenic activity of the CK2 inhibitor quinalizarin in a rat aortic ring assay and its effect on the expression of individual CK2 subunits and on kinase activity in endometrial tissue. Moreover, endometriotic lesions were induced in dorsal skinfold chambers of quinalizarin- and vehicle-treated C57BL/6 mice to study their vascularization and morphology by means of repetitive intravital fluorescence microscopy and histology. Our results demonstrate that quinalizarin dose-dependently inhibits vascular sprouting. In addition, treatment of endometrial tissue with quinalizarin reduces CK2 activity without affecting the expression of the three CK2 subunits α, α' and β. In the dorsal skinfold chamber model of endometriosis, quinalizarin inhibits the vascularization of endometriotic lesions, which exhibit a significantly decreased vascularized area and functional capillary density when compared to those of vehicle-treated controls. This is associated with a reduced lesion size and histological fraction of endometrial glands. These findings indicate that CK2 is a regulator of angiogenesis in endometriotic lesions. Accordingly, inhibition of CK2 represents a novel option in the development of anti-angiogenic strategies for the treatment of endometriosis.
    No preview · Article · Feb 2012 · Angiogenesis
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    ABSTRACT: Cancer-associated fibroblasts (CAFs) are thought to play an essential role in cancer initiation and development. However, little research has been done to evaluate the role of CAFs in epithelial ovarian cancer (EOC) development. To address this issue, ninety-one specimens were immunostained with α-smooth muscle actin (α-SMA) and fibroblast activation protein (FAP) antibodies to quantify CAFs, and antibodies D2-40 and CD34 to evaluate the lymphatic vessel density (LVD) and microvessel density (MVD) of the lesions. We found there were no α-SMA or FAP positive fibroblasts in normal ovary tissues. More CAFs were found in EOC than in borderline tumors and benign tumors (P<0.01). Abundant CAFs in EOC were associated with advanced-stage disease (P=0.002), the occurrence of lymph node metastases (P=0.02) and omentum metastases (P<0.0001), and increased LVD (P=0.002) and MVD (P=0.0004). CAFs isolated from EOC tissues induced more cancer cells to invade (P=0.003) and migrate (P=0.005) compared with normal fibroblasts (NFs) isolated from normal ovary tissues in vitro. Our data indicate that CAFs play a vital role in ovarian cancer progression and metastasis. Targeting CAFs as a therapeutic strategy against ovarian cancer is an intriguing concept that needs further study.
    No preview · Article · Feb 2011 · Cancer letters
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    ABSTRACT: There has been emergence of evidence suggesting that specific variants of the vascular endothelia growth factor (VEGF) family, based on their ability to regulate angiogenesis, would be pivotal in the pathogenesis of endometriosis. This study was aimed at determining whether high levels of VEGF-A could be found in the serum and peritoneal fluid (PF) of patients with endometriosis. VEGF-A levels were measured by enzyme-linked immunosorbent assay (ELISA) in serum and PF from 46 patients with surgically confirmed endometriosis, and 40 controls with no clinical evidence of the disease or detectable endometriotic lesions at the time of surgical examination. The results showed the mean VEGF-A levels were significantly higher in the serum and PF of patients with endometriosis than in the controls. The VEGF-A levels in the serum and PF of patients with severe endometriosis (stages III-IV) were significantly higher than in those with minimal endometriosis (P<0.001). It was concluded that endometriosis was associated with significant modulation in the levels of circulating VEGF-A.
    No preview · Article · Oct 2009 · Journal of Huazhong University of Science and Technology