Impact of alendronate and VEGF-antisense combined treatment on highly VEGF-expressing A431 cells

Formation of 1-Hydroxymethylene-1,1-bisphosphinates through the Addition of a Silylated Phosphonite on Various Trivalent Derivatives

An easily handled one-pot synthetic procedure was previously developed for the synthesis of bisphosphinates starting from acyl chlorides. Herein, other trivalent derivatives as acid anhydrides and activated esters were tested to form various bisphosphinates. This modulation of the reactivity can be controlled according to the nature of the acid derivative for the use of sensitive and functionalized substrates.

Effect of shRNA-mediated knockdown of vascular endothelial growth factor on the proliferation of choroid-retinal endothelial cells under hypoxic conditions

The aim of the present study was to investigate the role of vascular endothelial growth factor (VEGF) in cell proliferation under hypoxic conditions. Gene knockdown of VEGF was conducted in the choroid-retinal endothelial RF/6A cell line by transfection with short hairpin RNA (shRNA), in which a shRNA fragment against VEGF was synthesized and cloned into the vector, pSilencer 2.1-U6 neo. Subsequently, a model of hypoxia was established in the RF/6A cell line via treatment with CoCl₂, into which the recombinant plasmids, containing the VEGF-targeting shRNA (p-shRNA), were transfected. The study included four treatment groups, namely a control group (normal group), a hypoxia group treated with CoCl₂ (CoCl₂ group), a control plasmid group that were subjected to CoCl₂ treatment and transfection with a pSilencer 2.1-U6 neo plasmid without the shRNA (CoCl₂ + p-NC group), and a group treated with CoCl₂ and transfected with a pSilencer 2.1-U6 neo plasmid containing the VEGF-targeting shRNA (CoCl₂ + p-shRNA group). Subsequent to treatment, the mRNA and protein expression levels of VEGF were evaluated using quantitative polymerase chain reaction and western blot analysis, respectively, In addition, cell proliferation was assessed. RF/6A cells treated with CoCl₂ reduced cell connectivity, irregular morphology and reduced thickness compared with the cells in the normal group. However, cells in the CoCl₂ + p-shRNA group exhibited an improved morphology compared with the CoCl₂ and CoCl₂ + p-NC groups. Cell proliferation in the CoCl₂ group was enhanced in a time-dependent manner. However, the hypoxia-induced increase in cell proliferation was significantly inhibited in the CoCl₂ + p-shRNA group, with inhibition rates of 16, 32 and 38% at 24, 48 and 72 h, respectively. The mRNA and protein expression levels of VEGF were increased in the CoCl₂ group when compared with the normal group, and these hypoxia-induced increases in VEGF expression were reduced in the CoCl₂ + p-shRNA group. Therefore, the results indicated that the targeted knockdown of VEGF in vascular endothelial cells may be effective for the treatment of retinal neovascularization diseases.

Bisphosphonate prodrugs: synthesis and biological evaluation in HuH7 hepatocarcinoma cells

We investigated the biological effects of new synthesized bisphosphonates (BPs) on HuH7 hepatocarcinoma cells. BPs containing p-bromophenyl (R1 = p-Br, Ph, 2) in their side chain were the more potent to inhibit HuH7 cell viability. In addition, phenyl diesterified analogues (R2 = R3 = Ph, 2a) were more potent than methyl (R2 = R3 = Me, 2b) or non-esterified BPs (2) inducing more necrosis suggesting that they better entered into cells. Phosphodiesterase inhibitor (IBMX) reversed the effect of the esterified BPs and not that of non-esterified ones suggesting role of cell phosphodiesterases to release active BPs. BP analogues inhibited HuH7 cell migration but esterified ones had no effect on invasion due to the hiding of phosphonic groups. All together, these results indicated the therapeutic interest of these new BP prodrugs.