Send to:

Choose Destination
See comment in PubMed Commons below
PLoS One. 2012;7(3):e33597. doi: 10.1371/journal.pone.0033597. Epub 2012 Mar 16.

Nuclear factor-kappa B inhibition can enhance apoptosis of differentiated thyroid cancer cells induced by 131I.

Author information

  • 1Department of Nuclear Medicine, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.



To evaluate changes of nuclear factor-kappa B (NF-κB) during radioiodine 131 ((131)I) therapy and whether NF-κB inhibition could enhance (131)I-induced apoptosis in differentiated thyroid cancer (DTC) cells in a synergistic manner.


Three human DTC cell lines were used. NF-κB inhibition was achieved by using a NF-κB inhibitor (Bay 11-7082) or by p65 siRNA transfection. Methyl-thiazolyl-tetrazolium assay was performed for cell viability assessment. DNA-binding assay, luciferase reporter assay, and Western blot were adopted to determine function and expression changes of NF-κB. Then NF-κB regulated anti-apoptotic factors XIAP, cIAP1, and Bcl-xL were measured. Apoptosis was analyzed by Western blot for caspase 3 and PARP, and by flow cytometry as well. An iodide uptake assay was performed to determine whether NF-κB inhibition could influence radioactive iodide uptake.


The methyl-thiazolyl-tetrazolium assay showed significant decrease of viable cells by combination therapy than by mono-therapies. The DNA-binding assay and luciferase reporter assay showed enhanced NF-κB function and reporter gene activities due to (131)I, yet significant suppression was achieved by NF-κB inhibition. Western blot proved (131)I could increase nuclear NF-κB concentration, while NF-κB inhibition reduced NF-κB concentration. Western blot also demonstrated significant up-regulation of XIAP, cIAP1, and Bcl-xL after (131)I therapy. And inhibition of NF-κB could significantly down-regulate these factors. Finally, synergism induced by combined therapy was displayed by significant enhancements of cleaved caspase 3 and PARP from Western blot, and of Annexin V positively staining from flow cytometry. The iodine uptake assay did not show significant changes when NF-κB was inhibited.


We demonstrated that (131)I could induce NF-κB activation, which would attenuate (131)I efficacy in DTC cells. NF-κB inhibition by Bay 11-7082 or by p65 siRNA transfection was effective in suppressing NF-κB regulated anti-apoptotic changes and in combined regimen apoptosis was achieved synergistically.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Public Library of Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk