1.1. Background: The Sodium/Iodide Symporter (NIS) is a transmembrane glycoprotein with a molecular weight of 87 kDa and 13 transmembrane domains. NIS mediates the uptake of iodide into follicular cells of the thyroid gland and is the first step in the synthesis of thyroid hormone. This is achieved by transporting two sodium cations (Na+) for each iodide anion (I−) into the cell. Studies have shown that NIS expression in follicular cancer cells of the thyroid gland can be exploited in the treatment of thyroid cancer with 131I. Recent studies demonstrate that elevation of NIS expression may be augmented by treatment with the antibiotic doxorubicin and may not be limited to thyroid follicular cells.
1.2. Title: Therefore, this study was conducted in order to test the hypothesis that NIS expression and function can be augmented in the MDA-MB-231 breast cancer cells by doxorubicin treatment.
1.3. Method and Finding: This hypothesis were tested by treating MDA-MB-231 cells with doxorubicin at 0, 0.2, 2, and 20µM for 48hrs followed by measurement of NIS expression using Western blot and immunofluorescence assays and Iodine uptake using an uptake assay.
1.4. Conclusion: Our studies showed that NIS expression was augmented by doxorubicin treatment in MDA-MB-231 cells. Our studies also showed that increased expression of NIS corresponded to increased Iodine uptake. Thus, the use of the antibiotic doxorubicin in conjunction with radioiodine may provide a potential treatment for breast cancer.