title: Suppression of type 1 Insulin-like growth factor receptor expression by small interfering RNA inhibits A549 human lung cancer cell invasion in vitro and metastasis in xenograft nude mice.
abstract: Cancer invasion and metastasis, involving a variety of pathological processes and cytophysiological changes, contribute to the high mortality of lung cancer. The type 1 insulin-like growth factor receptor (IGF-1R), associated with cancer progression and invasion, is a potential anti-invasion and anti-metastasis target in lung cancer. To inhibit the invasive properties of lung cancer cells, we successfully down-regulated IGF-1R gene expression in A549 human lung cancer cells by small interfering RNA (siRNA) technology, and evaluated its effects on invasion-related gene expression, tumor cell in vitro invasion, and metastasis in xenograft nude mice. A549 cells transfected with a plasmid expressing hairpin siRNA for IGF-1R showed a significantly decreased IGF-1R expression at the mRNA level as well as the protein level. In biological assays, transfected A549 cells showed a significant reduction of cell-matrix adhesion, migration and invasion. Consistent with these results, we found that down-regulation of IGR-1R concomitantly accompanied by a large reduction in invasion-related gene expressions, including MMP-2, MMP-9, u-PA, and IGF-1R specific downstream p-Akt. Direct tail vein injections of plasmid expressing hairpin siRNA for IGF-1R significantly inhibited the formation of lung metastases in nude mice. Our results showed the therapeutic potential of siRNA as a method for gene therapy in inhibiting lung cancer invasion and metastasis.
authors.affiliation: Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China. dr_dongaiqiang@sina.com.
authors.forename: Jianfang
authors.initials: J
authors.lastname: Qian
authors.forename: Aiqiang
authors.initials: A
authors.lastname: Dong
authors.forename: Minjian
authors.initials: M
authors.lastname: Kong
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Ma
authors.forename: Junqiang
authors.initials: J
authors.lastname: Fan
authors.forename: Guanyu
authors.initials: G
authors.lastname: Jiang
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness / Q000517:prevention & control*; D034741:RNA, Small Interfering / Q000235:genetics*; D017526:Receptor, IGF Type 1 / Q000235:genetics*; D014183:Transplantation, Heterologous
chemical_list: D034741:RNA, Small Interfering; D017526:Receptor, IGF Type 1