Iodide Transport in a Continuous Line of Cultured Cells from Rat Thyroid

Abstract

The properties of TSH-dependent iodide (I-) uptake are defined for a cloned, continuously growing, functioning rat thyroid cell line (FRTL-5 cells). Since these cells grow without a lumen and are therefore restricted in their ability to iodinate thyroglobulin, the FRTL-5 cells offer the opportunity to directly study transport processes across the membrane into the cell as well as the process whereby I- moves from the cell. FRTL-5 cells concentrate I- approximately 30-fold and exhibit many of the properties of I- uptake seen in thyroid tissue slice and primary cell culture systems. In these cells, accumulation of I- is consistent with a Na+-dependent carrier model for I- uptake, and effects on the influx and efflux processes can be dissociated. Because FRTL-5 cells can be maintained in culture indefinitely and can provide large quantities of a homogeneous functional thyroid cell preparation for study, these cells offer the unique opportunity to further define the mechanism and kinetics of I- transport in a less complex system.

Sodium iodide symporter-mediated radioiodide imaging and therapy of ovarian tumor xenografts in mice

“…The ability of the cells to concentrate iodide was determined as described by Weiss et al 36 Briefly, following transfection, cells were incubated in HBSS containing 10 mM HEPES, 10 mM NaI and 0.1 mCi of Na 125 I/ml, pH 7.3, and 10 mM KClO 4 , a competitive inhibitor of iodide uptake by NIS, was included in control wells. Following a 45-min incubation at 371C, cells were washed with ice-cold phosphate-buffered saline (PBS), lysed with 1 M NaOH, and concentrated iodide was measured on a g-counter.…”

Expression and activity of human Na+/I− symporter in human glioma cells by adenovirus-mediated gene delivery

“…At 24 h after infection, cells were washed with buffered HBSS described by Weiss et al 22 and incubated for 1 h at 37°C, 5.0% CO 2 with buffered HBSS (1 ml per well) containing 1.0 Ci Na 125 I and 5 m of NaI carrier. The radioactive HBSS was aspirated, cells were quickly washed twice with buffered HBSS, and 1 ml iodide-free buffered HBSS was added to the cells.…”

Enhanced iodide transport after transfer of the human sodium iodide symporter gene is associated with lack of retention and low absorbed dose

“…2,12 In the presence of 74 kBq Na 125 Iodide (Amersham Buchler Germany; specific activity 625.3 MBq/mg; radioactive concentration 3.7 GBq/ml; radiochemical purity 99.3%) the recombinant cell line AT1hNIShyg9 and wild-type AT1 cells were cultured for 1, 2, 5, 10, 30 min, or 1, 2 and 4 h in six-well plates. In order to simulate the clinical situation of radioiodine treatment, we added no cold NaI.…”

“…For the modulation of the iodide uptake hNISexpressing and wild-type cells were incubated for 1 h in Na 125 I medium (74 kBq) or Na 125 I-medium supplemented with 10 or 50 mM sodium perchlorate (SigmaAldrich, Taufkirchen, Germany), 0.5 mM ouabain, 100 or 300 mM of the anion channel blocker 4,4 0 -diisothiocyano-2,2 0 -disulfonic acid stilbene (DIDS; Sigma-Aldrich) or 10 mM of the proton conductor carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP; Sigma-Aldrich) according to Weiss et al 2 Thereafter, the cells were washed, lysed and counted as described.…”

“…This process against an electrochemical gradient requires energy, is coupled to the action of Na + /K + -ATPase and is also stimulated by TSH. [1][2][3][4][5] Since the cloning of the human and rat cDNA sequences several experimental studies have been performed, which investigated the recombinant expression of the hNIS gene in malignant tumors by viral transfer of the hNIS gene under the control of different promoter elements. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Although all of them reported high initial uptake in the genetically modified tumors, differing results have been obtained concerning the efficiency of radioiodine treatment based on NIS gene transfer with generally very high doses given to tumorbearing mice.…”