TY - JOUR T1 - Control of 5' untranslated region of sodium iodide symporter gene to enhance gene expression JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1611 LP - 1611 VL - 50 IS - supplement 2 AU - C Ke AU - L Hwu AU - Y Chen AU - W Kuo AU - R Liu Y1 - 2009/05/01 UR - http://jnm.snmjournals.org/content/50/supplement_2/1611.abstract N2 - 1611 Objectives The rapid radioiodide efflux weakens the efficacy of sodium iodide symporter (NIS) in cancer gene imaging and radioiodide therapy. Untranslated regions (UTR) of specific genes are important regulator of mRNA stability, localization and translation. However, UTRs possess positive regulation in some genes but negative regulation in others. The strength of regulation by UTRs also differs in various genes. This study aim to up-regulate NIS expression by control of UTR. Methods Anaplastic thyroid cancer cell line ARO and non-small cell lung cancer cell line H1299 were transfected with constructs which contains coding region of NIS gene (NIS-CDS) equipped with or without 5’UTR of NIS gene. 48 hr after transfection, radioiodide uptake was assayed. Total RNA were isolated from cells and realtime PCR was carried out to evaluate the NIS gene expression. Cells were also transfected with construct containing firefly luciferase equipped with or without 5’UTR of NIS gene. Results 5’UTR of NIS gene has a negative control in NIS protein translation in both thyroid cancer and lung cancer cells. In the presence of 5’UTR, the luciferase activity had 30% reduction, compared to that without 5’UTR. In cellular uptake, ARO cells transfected with 5’UTR-containing NIS construct accumulated 90% of I-125 compared with NIS-CDS construct. H1299 cells transfected with NIS-CDS construct had 3 times of I-125 accumulation compared with 5’UTR-containing NIS construct. Conclusions To enhance the expression of NIS gene, NIS-CDS serves as a better expressing construct than that contains 5’UTR. ER -