| Godbole et al., Lucknow, India, studied the expression of NIS in normal and cancerous breast tissue as it is known that iodine accumulation is elevated in breast tumor tissue. They found 4-6 fold increased expression of NIS in breast carcinoma tissue as compared to normal breast tissue. Plasma inorganic iodine was also increased in breast carcinoma patients as compared to controls. After chemotherapy both NIS expression and plasma iodine levels decreased significantly. The authors suggest that their finding may open the way to radioactive iodine treatment in patients with breast carcinoma. Smit et al., Leiden en Wageningen, The Netherlands, transfected human NIS cDNA in human thyroid carcinoma cell lines that lost the capability to concentrate iodine. They could re-establish iodine uptake in these cells that could virtually completely be inhibited by perchlorate. (Comment: These studies open the possibility for transfection of NIS in humans with thyroid carcinoma when tumor tissue has lost its capability to concentrate iodide.) Dohan et al., New York, NY, USA, and Budapest, Hungary, investigated NIS expression by immunoblot analysis, immunohistochemistry and flow cytometry in patients with different types of carcinoma. They found expression negative in 1 thyroid medullary carcinoma, and positive in 7/14 thyroid papillary carcinomas, and 4/5 thyroid follicular carcinomas. Furthermore, 9/16 cardia tumors, 3/12 oesophageal carcinomas and 9/16 breast carcinomas showed expression as well. Spitzweg et al., Rochester, MN, USA, and Marburg, Germany, tested if it is possible to express NIS functionally in prostate carcinoma in vivo in mice. Xenografts derived from a human prostatic adenocarcinoma cell line were established in athymic nude mice and transfected with NIS cDNA. NIS protein expression in the mice was confirmed immunohistochemically and after intratumoral administration of radioactive iodine. Administration of 131-iodine reduced tumor volume by 75% as compared to control tumors. (Comment: This report is one of the most important ones of this meeting and opens a possibility to treat patients with prostate carcinoma with radioactive iodine after transfection of NIS.) |
