title: Cytochalasin D promotes pulmonary metastasis of B16 melanoma through expression of tissue factor.
abstract: Cytochalasin D (CytD) targets actin, a ubiquitous protein in eukaryotic cells. Previous studies have focused mainly on the antitumor effects of CytD. We previously found CytD to promote lung metastasis in B16 melanoma cells, which we had not anticipated, and, therefore, in the present study we investigated the possible underlying mechanisms. B16 melanoma cells were co-cultured with CytD and other agents and used to establish a lung metastatic model. In this B16 melanoma metastatic model, significantly increased lung metastasis and lung weight were found in CytD-treated mice, which was almost completely suppressed by tissue factor (TF) RNA interference expressed via lentivirus. The results of northern and western blot, and real-time RT-PCR analysis showed that the expression of TF was significantly upregulated in B16 cells treated with CytD but was significantly inhibited by TF RNA interference. In addition, upregulation and phosphorylation of mitogen-activated protein kinase p38 were also found in the metastatic lung tissues treated with CytD and in the B16 cells co-cultured with CytD and factor VIIa (FVIIa), but not in cells cultured with CytD, dimethyl sulfoxide or FVIIa alone. These results indicate that CytD stimulates the expression of TF in B16 melanoma cells, activating both coagulation-dependent and -independent pathways via binding to FVIIa, eventually promoting lung metastasis. TF interference is a potential approach to the prevention of B16 melanoma metastasis.
authors.affiliation: Hainan Provincial Key Laboratory of Tropical Medicine, Hainan Medical College, Haikou, Hainan, P.R. China.
authors.forename: Feng-Ying
authors.initials: FY
authors.lastname: Huang
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Mei
authors.forename: Guang-Hong
authors.initials: GH
authors.lastname: Tan
authors.forename: Hao-Fu
authors.initials: HF
authors.lastname: Dai
authors.forename: Yue-Nan
authors.initials: YN
authors.lastname: Li
authors.forename: Jun-Li
authors.initials: JL
authors.lastname: Guo
authors.forename: Yong-Hao
authors.initials: YH
authors.lastname: Huang
authors.forename: Huan-Ge
authors.initials: HG
authors.lastname: Zhao
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Zhou
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Lin
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D015638:Cytochalasin D / Q000494:pharmacology*; D015942:Factor VIIa / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D008175:Lung Neoplasms / Q000556:secondary*; D008546:Melanoma, Experimental / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010766:Phosphorylation; D034622:RNA Interference; D034741:RNA, Small Interfering; D013925:Thromboplastin / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D019384:Nucleic Acid Synthesis Inhibitors; D034741:RNA, Small Interfering; D015638:Cytochalasin D; D013925:Thromboplastin; D048051:p38 Mitogen-Activated Protein Kinases; D015942:Factor VIIa