Objective: To establish cervical cancer Hela-NIS(+) cell lines stably expressing human sodium iodide symporter (NIS), and explore the feasibility of imaging and treatment of cervical cancer xenograft model using 131I mediated by NIS gene.Methods: FL*-hNIS/pcDNA3 recombinant plasmid was amplified and extracted from bacteria DH5a, and analysed by electrophoresis following digestion, and the plasmid (FL *-hNIS/pcDNA3)was used to transfect human cervical cancer Hela cell line with FUGENE HD.Six clones were isolated after selective growth under G418 and evaluated for NIS expression by flow cytometry (FCM).Clone Hela-NIS(+) was identified by its ability to expand in selection media and its highest level of expression efficiency of NIS.The total RNA and membrane protein were extracted from Hela-NIS(+) cells and control cells, and the expression of NIS gene and NIS protein were detected by RT-PCR and western blot, respectively.The cervical cancer xenograft models were established with Hela-NIS(+) cells and Hela cells, respectively.The Hela-NIS(+)xenograft models were dynamically imaged with radioactive isotope 131I and 99TcmO4-at various time points.The Hela-NIS(+) cervical cancer xenograft models were randomly divided into several groups, and therapeutic effects of 131I at various levels were investigated following intraperitoneal injection.Results: hNIS gene was successfully transfected into human cervical cancer Hela cell line.One Hela-NIS(+) cell line stably expressing NIS gene was obtained, and its highest level of expression efficiency of NIS was (33.81±2.06)% with FCM.The expression of NIS gene was detected by RT-PCR from Hela-NIS(+) cells, and the expression at protein level (~97KD) was detected by western blot.Hela-NIS(+) human cervical cancer xenografts were established successfully in nude mice.The Hela-NIS(+) xenografts significantly accumulated radioactivity after intraperitoneal injection of 131I, and the radioactivity was persistently present until 20h post-injection, while the control group(Hela xenografts) had no radioactive accumulation, The T/B value of the Hela-NIS(+)xenografts reached 17.34 at 8h post-injection.The result of imaging with 99TcmO4-showed that the radioactivity was persistently present in Hela-NIS(+) xenografts for almost 25h.The Hela-NIS(+)xenografts shrinked after being administrated different therapeutic doses of 131I.Conclusions: Hela-NIS(+) cell lines stably expressing NIS protein were established successfully.Hela-NIS(+) cervical cancer xenografts in nude mice could persistently accumulate 131I or 99TcmO4-for a long time, and could be treated successfully with 131I.131I treatment mediated by NIS transgene could represent a promising clinical application in the treatment of cancer in the future.