title: RNA interference (RNAi)-mediated vascular endothelial growth factor-C (VEGF-C) reduction interferes with lymphangiogenesis and enhances epirubicin sensitivity of breast cancer cells.
abstract: It has been reported that over-expression of vascular endothelial growth factor-C (VEGF-C) in tumors leads to increased lymphangiogenesis and resistance to chemotherapy. Therefore, we hypothesized that VEGF-C would be a good molecular target for cancer gene therapy. In this study, we silenced the expression of VEGF-C with the highly specific post-transcriptional suppression of RNA interference (RNAi) in human breast cancer MCF-7 cell line. The expression of VEGF-C was examined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), and the effect of plasmid on human lymphatic endothelial cells (HLECs) in vitro was analyzed by migration and 3-(4, 5-dimethylt-hiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The sensitivity to anticancer agents was evaluated by MTT and apoptosis assay, and apoptosis-related genes bcl-2/bax ratio was determined by Western Blotting. Results showed that of three siRNA-expressing vectors, P-1/siRNA most significantly suppressed the expression of VEGF-C mRNA and protein (38.1% of control and 117.8 +/- 24.2 pg/ml, respectively) and interfered with proliferation and migration of HLECs in vitro. Moreover, transfection of VEGF-C/siRNA combined with Epirubicin markedly decreased breast cancer cells viability, reaching up to 38.5%, and increased apoptosis rate from 13.1% to 38.9%, as determined by decrease of bcl-2/bax ratio. In summary, VEGF-C would be a good molecular target, and a combination of Epirubicin and RNAi targeting VEGF-C could be an effective means for suppressing lymphatic metastasis and enhancing chemosensitivity of human breast cancer cells.
authors.affiliation: Department of Anatomy, School of Medicine, Shandong University, No. 44, WenHua Xi Road, JiNan, Shandong 250012, PR China. spmy73@yahoo.com.cn
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Liu
authors.forename: Lu-Wan
authors.initials: LW
authors.lastname: Wei
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Wu
authors.forename: Zhi-Yu
authors.initials: ZY
authors.lastname: Liu
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology; D015251:Epirubicin / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D042583:Lymphangiogenesis / Q000187:drug effects*; D008221:Lymphoid Tissue / Q000166:cytology / Q000187:drug effects; D034622:RNA Interference / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D014162:Transfection; D042582:Vascular Endothelial Growth Factor C / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; D042582:Vascular Endothelial Growth Factor C; D049452:Green Fluorescent Proteins; D015251:Epirubicin