ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of nucleolin silencing on the differentiation of rat neural stem cells (NSCs) and the role of Wnt signaling pathway in mediating such effect.</p><p><b>METHODS</b>Adenovirus vectors expressing small interfering RNA (siRNA) against nucleolin were constructed, verified, and packaged in HEK293A cells. The adenovirus was then transfected into NSCs isolated from neonatal SD rats and the differentiation of the NSCs was examined by detecting the expressions of neuron specific encloase (NSE) and glial fibrillary acidic protein (GFAP) using immunocytochemistry. The expressions of nucleolin, nestin, Wnt3, and β-catenin in the cells were determined with Western blotting.</p><p><b>RESULTS</b>Restriction endonuclease and sequencing analysis verified successful construction of the adenoviral vector expressing nucleolin siRNA (nucleolin-siRNA2). Infection of rat NSCs with nucleolin-siRNA2 significantly lowered nucleolin protein expression as compared with that in negative and blank control groups (P<0.05). The percentages of NSE-positive cells and GFAP-positive cells were significantly higher in NSCs infected with nucleolin-siRNA (P<0.01); the infection also resulted in obviously lowered expression of nestin protein and increased expressions of Wnt3 protein and β-catenin nucleoprotein in the cells.</p><p><b>CONCLUSIONS</b>Nucleolin silencing by adenovirus-mediated RNA interference induces the differentiation of NSCs into neurons and astrocytes, which is related with the activation of Wnt signaling pathway.</p>
ABSTRACT
OBJECTIVE@#To investigate the lymphangiogenesis and location of tumor lymphatic vessels induced by vascular endothelial growth factor C (VEGF-C) in primary breast cancer.@*METHODS@#The expression of VEGF-C mRNA in 89 cases of primary breast cancer was detected by in situ hybridization, and lymphatic vessels with vascular endothelial growth factor receptor-3 (VEGFR-3) were labeled by immunohistochemistry SP method.@*RESULTS@#VEGF-C mRNA expressed in 49 of all 89 cases of primary breast cancer, and the expression rate was 55.06%. The expression of VEGF-C mRNA was positively correlated with lymphatic vessel density (LVD) and axillary lymph node metastasis, LVD and the rate of axillary lymph node metastasis were significantly higher in VEGF-C mRNA positive group than those in the negative group (both P < 0.05). Different levels of lymphangiogenesis took place in all cases of breast cancer, but it was mainly located in tumor stroma, and apparently mature lymphatic vessels were not found in cancer nests. LVD was positive related with the clinical stage and axillary lymph node metastasis in breast cancer; the clinical stage, the LVD, the axillary lymph node metastasis in positive group were higher than those in the negative group (P < 0.05).@*CONCLUSION@#The expression of VEGF-C mRNA is positively correlated with lymphangiogenesis and axillary lymph node metastasis in primary breast cancer. Lymphangiogenesis induced by VEGF-C predominantly takes place in the tumor stroma tissue, and mature lymphatic vessels are not found in cancer nests.