Abstract： Objective To construct a recombinant adenovirus vector containing the human NIS gene with the myosin light chain-2(MLC-2v) gene as the promoter and evaluate its specific expression and feasibility as a reporter gene in cardiomyocytes.Methods MLC-2v promoter and NIS were subcloned into an adenovirus shuttle vector,and forwarded by homologous recombination in the bacteria BJ5183 containing AdEasy-1 plasmid.Positive recombinant adenovirus vector was selected,packaged and amplified in the HEK293 cells to obtain recombinant adenovirus Ad-MLC-NIS.Ad-cytomegaoviyns (CMV)-NIS with cytomcgalovirus as the promotcr,Ad-MLC without NIS and Ad-NIS without promoter were constructed as the controls.Cardiomyocytes and non-cardiomyocytes were then infected by the adenovirus.The protein expression was tested by Western blot analysis.The function and features of NIS protein were evaluated by dynamic iodide uptake and NaClO4 iodine uptake inhibition test in vitro.The viability and proliferation of cardiomyocytes after adenovirus transfection and radioiodine incubation were checked by trypan blue staining.Results Recombinant NIS adenovirus was successfully constructed.Western blot analysis showed that the NIS protein was highly expressed in cardiomyocytes transfected with Ad-MLC-NIS,and all cells transfected with Ad-CMV-NIS.However,in non-cardiomyocytes transfected with Ad-MLC-NIS,little NIS protein was detected.Dynamic iodine uptake tests showed that the peaks of iodide uptake of the three different cell lines (H9C2,A549,U87 cell) transfected with Ad-MLC-NIS were 5844.0,833.6 and 846.0 counts · min-1,respectively.The iodide uptake function of H9C2 was inhibited by NaClO4.There was almost no change in cell viability and proliferation when the MOI was 100.Conclusions Ad-MLC-NIS allows myocardial specific expression of an external gene,and the cardiomyocytes with NIS expression are capable of iodine uptake.Further research of NIS as a reporter gene in myocardium is needed.