A Study Of The Nasopharyngeal Carcinoma Cell Targeted Gene Delivery Vector

Recently, the incidence of cancer rising considerablly and malignancy hasbeen a grave threat to human being. Nasopharyngeal carcinoma, which is primaryfrom nasopharyngeal epithelial tissue, presents a low incidence in most regions buta high rate in China. However, traditional treatments are not so effective in terms oflate-stage nasopharyngeal carcinoma. Thus, it is significant to introduce the genetherapy in order to establish a contact between these two therapies. It is veryimportant to point out the two key challenges in gene therapy study: effectivetherapeutic gene and safe delivery vehicles with high transfection efficiency underbody fluid situation.This study took folate as a targeting molecular, combined the favorableproperties of cationic liposomes, PEI and NLS, to prepare a new targeting genedelivery vector to nasopharyngeal carcinoma.First of all, the function of TRAIL gene to induce tumor cell apoptosis wasinvestigated. Based on a series of experiments contains TRAIL receptors detection,cell apoptosis state observation and MTT test, the results suggested that TRAILgene was able to induce cell apoptosis of nasopharyngeal carcinoma and could beused as a candidate in gene therapy.Secondly, NLS in different proportion was complexed with PEI and cationicliposomes. Transfection and cytotoxicity results showed that NLS couldsignificantly increase the transfection of non-viral vectors under a optimizedproportion. Furthermore, the method of prepare complex contains cationic liposome, PEIand DNA was improved from two-step to one-step. This new method obtained aPEIlip/DNA complex with size about150nm and zeta about45mV. Transfectionand cytotoxicity results showed that PEIlip/DNA presented a good safety andhigher level transfection efficiency at the presence of serum.ELISA test suggested that CNE and HNE-1strongly expressed the folatereceptor. So, it is reasonable to take folate as a targeting molecular towardsnasopharyngeal carcinoma. Fluorescently labeled folate liposomes was preparedto incubate with CNE and it was identified and taken into cell through endocytosisunder the observation by fluorescence microscope.Finally, the transfection efficiency of folate modified fPEG-PEIlip/DNA complexwas tested and the results showed that folate remarkablly improved the efficiencyof transfection. And it is further improved with the addition of NLS.It is concluded that this paper successfully prepared a target gene deliveryvector of nasopharyngeal carcinoma. This carrier had a better security and highertransfection efficiency. Thus, it is promising in gene therapy vector ofnasopharyngeal carcinoma.