Dandekar et al pointed out that reduction of COX-2 suppresses tumor growth and improves efficacy of chemotherapeutic drugs in prostate cancer [27–29]. Other groups reported that the COX-2 Selleckchem PKC412 inhibitors attenuate migration and invasion of breast cancer cells [30]. These data indicate that, as a critical regulator of proliferation of tumor cells, COX-2 is a considerable target for inhibiting growth, triggering apoptosis, and reducing invasion activity. To this day, there have been many strategies used to inhibit COX-2 expression and activity, including inhibitors and antisense oligonucleotides and RNAi [27, 29, 30]. Selective COX-2 inhibitors ARRY-162 both inhibit

tumor cell growth and boost chemosensitivity or radiosensitivity of malignancies [31, 32]. To ensure the efficacy and specificity of COX-2 as a therapeutic target, we employed RNAi technology. RNAi refers to the introduction of homologous double stranded RNA (dsRNA) to specifically target a gene’s product, Evofosfamide research buy resulting

in null or hypomorphic phenotypes [33, 34]. It has demonstrated great prospects for studying gene function, signal transduction research and gene therapy. We used RT-PCR and western blotting to proof the efficacy of LV-COX-2siRNA-1 on COX-2 expression in 293T and SaOS2 cells. LV-COX-2siRNA-1 was applied and the expression of COX-2 mRNA and protein were significantly inhibited. Accumulating evidence has indicated that COX-2 promotes tumor growth, increases cancer cell invasiveness and metastasis through its catalytic activity [35, 36]. Not only COX-2 transfection but also PGE2 treatment enhances Methocarbamol cell migration and invasion in various types of human cancers [37–41]. In the present study, the invasion and migration ability of the SaOS2 cells were tested and found that COX-2 gene knockdown by RNAi resulted in a decreased level of invasion and migration. Therefore, there is a strong relationship between COX-2 and the invasion or migration ability of human osteosarcoma cells. It is well known that the growth of tumor cells depends on nutrition supply, which largely relies on angiogenesis. VEGF plays

a key role in normal and abnormal angiogenesis since it stimulates almost every step in the angiogenic process [42, 43]. Other factors that have been shown to stimulate angiogenesis include EGF, bFGF, hepatocyte growth factor, interleukin-8, and placental growth factor [44, 45]. Previous work indicated that COX-2 inhibitors blocked tumor growth via an antiangiogenic mechanism [46]. Moreover, studies demonstrated that there is a strong link between COX-2 expression and tumor angiogenesis [47]. Therefore, COX-2 overexpression may increase tumor blood supply and contribute to tumor growth. Our results suggest that knockdown of the COX-2 gene could suppress invasion and migration ability based on the down-regulation of vegfa, egf and bfgf expression in osteosarcoma cells.