also demonstrated a role for bFGF in the inhibition of gap juncti

also demonstrated a role for bFGF in the inhibition of gap junction (GJ) communication in the glioma

cell line, C6, following exogenous expression of connexin 43 [7]. Connexin 43 (Cx43) is the predominant component of GJs which are composed of six connexin proteins and are differentially expressed in various cell types [8]. Several studies have demonstrated that Cx43 is one of the major GJ proteins expressed by astrocytes and glial cells [9], and in high-grade human gliomas, its expression is significantly reduced. Decreased expression of Cx43 observed in a variety of tumor types, including tumors of the central nervous system, can also affect GJ intercellular communication (GJIC) [10, 11]. Restoration of GJIC by exogenous expression of Cx43 has reversed the transformed phenotype of certain tumor cells, including high-grade human gliomas [12, 13]. In addition, susceptibility of the transfected glioma cells to apoptosis was enhanced in response Q-VD-Oph cost to chemotherapeutic agents [14]. While it has been found that expression of Cx43 is inversely related to glioma cell proliferation and tumor grade [12, 15, 16], the specific regulatory mechanisms involving Cx43 in gliomas remains unclear. In the present study,

down-regulation of bFGF expression by a siRNA specifically targeted to bFGF is shown to significantly increase the DMXAA nmr expression of Cx43 without effecting the phosphorylation of Cx43 at S368 in the glioma cell line, U251. Methods Adenoviral vector construction From four siRNA sequences that were designed for targeting bFGF, an optimal target sequence (5′-CGAACTGGGCAGTATAAACTT-3′) was selected [17] and cloned into the plasmid vector, pGenesil-1. The siRNA expression cassette was subsequently excised from pGenesil-1 using EcoRI and HindIII and ligated into the linearized adenoviral shuttle vector, pGStrack-CMV. pGStrack-CMV-bFGF-siRNA why was then co-transfected with the pAd vector backbone into DH5α bacteria for the recombinant EPZ004777 mw generation of Ad-bFGF-siRNA, which was further amplified in HEK293 cells. Viral particles were purified using cesium chloride density

gradient centrifugation. Cell culture and adenovirus infection The human glioma cell line, U251, was maintained in Dulbcco’s modified Eagle medium (DMEM) supplemented with 10% heat inactivated fetal bovine serum (FBS), 100 U/ml of penicillin, and 100 μg/ml of streptomycin in a humidified atmosphere containing 5% CO2 at 37°C. All media and serum were purchased from Gibcol. U251 cells (1 × 105) in serum-free DMEM were infected with Ad-bFGF-siRNA at 100, 50, and 25 MOI (MOI is calculate as PFU/cell numbers) in a humidified atmosphere containing 5% CO2 at 37°C. Infection with Ad-GFP at 100 MOI served as a control. Virus-containing medium was removed 8 h later and replaced with fresh DMEM medium containing 10% FBS. Cells were incubated for another 72 h, then mRNA or protein was extracted. MTT assay for cell proliferation Cell proliferation was measured using MTT assay.

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