Bone Marrow Mesenchymal Stem Cells Modified Hybrid Baculovirus-Adeno-Associated Viral Vectors Targeting ¹³¹I Therapy Of Hypopharyngeal Carcinoma

Objective:Hypopharyngeal carcinoma is a common malignant tumor of the head and neck with a very poor prognosis.In this study,we investigated whether human bone marrow mesenchymal stem cells?BMSCs?possess potential homing capacity for hypopharyngeal carcinoma,and evaluated baculovirus-adeno-associated virus vector?BV-AAV?-mediated NIS gene-modified BMSCs targeting ¹³¹I therapy of hypopharyngeal carcinoma.Methods:1.we employed a hybrid baculovirus vector containing the Luc-P2A-eGFP fusion or sodium iodide symporter?NIS?sequence under the control of the cytomegalovirus promoter.To enhance the transfection efficiency,baculovirus vectors?Bac-CMV-Luc-P2A-eGFP-ITR and Bac-CMV-NIS-ITR?were flanked by inverted terminal repeats?ITRs?,which are key elements of adeno-associated viruses.2.The application value of this multi-gene delivery vector for genetically modified BMSCs was evaluated from three aspects:transduction efficiency,cytotoxicity,and correct expression of multiple genes.3.Transwell migration assays,bioluminescent imaging and micro-single-photon emission computed tomography imaging demonstrated the chemotaxis of BMSCs to hypopharyngeal carcinoma cells?FaDu cells?in vitro and in vivo.4.Glucose metabolism of hypopharyngeal carcinoma cells was assessed via ¹⁸F-FDG-PET/CT;PCNA and Tumor volume were monitored to assess tumor proliferation after treatment.Results:1.The infection efficiency of Bac-CMV-Luc-P2A-eGFP-ITR in BMSCs was as high as 92.84±1.14%with no obvious toxic effects at a multiplicity of infection?MOI?of 400.The ffLuc gene and eGFP gene fused via the P2A sequence were successfully expressed.2.Transwell migration assay showed dramatic increases in the migration of BMSCs and BMSCs infected with BV-AAV co-cultured with FaDu cells respectively.the BLI signal was also detected in the lungs firstly,but on the 5th day after injection,the signal could be found only in the tumor site.3.radioactive uptake could be detected by SPECT/CT 1 h after ¹²⁵I injection in the BMSCs-Bac-NIS group.4.After BMSCs-Bac-NIS was transplanted via tail vein,radioiodide therapy could inhibit tumor growth and prolong the survival of model rats and the SUVmax of ¹⁸F-FDG PET/CT decreased significantly.Conclusions:Our data have demonstrated that BV-AAV vectors represent a novel,highly efficient,and non-cytotoxic method for the functionalization of BMSCs;and BMSCs functionalized by BV-AAV can effectively home to hypopharyngeal cancer tissues.After BMSCs-Bac-NIS were transplanted via tail vein,radioiodide therapy can inhibit tumor growth and prolong the survival of model rats.Therefore,it will be a novel idea on the treatment against hypopharyngeal carcinoma.