RESUMEN
OBJECTIVE: To observe the influence of RNA interference targeting against survivin gene on the biological behaviors of human adenoid cystic cancer (ACC) cells and propose the action mechanism. METHOD: Specific siRNA (small interfering RNA) was constructed and transfected into ACC-2 cells using liposomes. The expressions of survivin and Caspase-3 in the transfected ACC-2 cells were detected by Western Blot and RT-PCR. Cell apoptosis was detected by transmission electron microscopy, TUNEL method and flow cytometry; ultrastructural changes and cell cycles were observed. RESULTS: Recombinant siRNA interference plasmid specifically targeting against survivin gene was constructed successfully. Survivin protein expression in the transfected ACC-2 cells was downregulated significantly, while Caspase-3 protein and mRNA expressions were upregulated and cell proliferation was inhibited considerably. CONCLUSION: Recombinant siRNA interference plasmid inhibited survivin mRNA and protein expressions at high efficiency, thereby inhibiting the proliferation of ACC cells.
RESUMEN
The combined radiation-wound injury is a refractory wound with decreased number or dysfunction of repairing cells and growth factors. This remains a challenge in clinical practice. The object of this study is to evaluate the therapeutic efficacy of a combination of human vascular endothelial growth factor 165 (hVEGF(165)) and human beta-defensin 3 (hBD3) in the treatment of such wounds. A plasmid-carrying hVEGF(165) gene and hBD3 gene was used to transfect rat bone-marrow-derived mesenchymal stem cells (BMSCs). The supernatant from the modified BMSCs significantly promoted the proliferation and cell migration of human endothelial cells and it also inhibited the growth of bacteria and fungus, demonstrating the successful expression of the transfected genes. The hVEGF(165)/hBD3-modified BMSCs were then injected into the sites of combined radiation-wound injury on rats. It demonstrated that wound-healing time was shortened significantly in the treated rats. The granulation tissue formation/maturation, skin appendage regeneration and collagen deposition were also improved significantly. Strong expression of hVEGF(165) and hBD3 was detected in the wound surface at early stage of the healing. The results indicate that topical transplantation of hVEGF(165)/hBD3-modified BMSCs promoted wound healing, and this gene therapy strategy presents a promising approach in the treatment of refractory wounds such as the combined radiation-wound injury.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Células Endoteliales/fisiología , Terapia Genética/métodos , Trasplante de Células Madre Mesenquimatosas/métodos , Traumatismos por Radiación/terapia , Factor A de Crecimiento Endotelial Vascular/uso terapéutico , beta-Defensinas/uso terapéutico , Animales , Humanos , Ratas , Ratas Sprague-Dawley , Transfección , Cicatrización de HeridasRESUMEN
OBJECTIVE: To investigate the influences of bicortical anchorage on values of natural frequencies of dental implants utilizing the 3-dimensional finite element analysis. METHODS: Using the commercial code of Solidworks, 3-D models of a screw-shaped dental implant and a mandibular bone segment were generated. After the 3-D implant-bone complex was meshed by ABAQUS software, effects of bicortical anchorage on the buccolingual and axial first-order natural frequencies of the implant were computed. RESULTS: Bicortical anchorage increased both the buccolingual and axial natural frequencies remarkably. As the bicortical anchorage got deeper, the frequencies correspondingly got higher. CONCLUSION: Bicortical anchorage can increase the buccolingual and axial primary stability of dental implants.