Morphological transformation of C3H 10T1/2 cells by 99mTc-cardiolite.
The induction of in vitro morphological transformation in C3H 10T1/2 cells by 99mTc-Cardiolite (contents of Cardiolite kit [hexakis(2-methoxyisobutylisonitrile) and other components] plus (99m)Tc generator eluate) was examined.


METHODS
Cells were grown for 48 h in the presence of 99mTc-Cardiolite or decayed 99mTc-Cardiolite (99mTc-Cardiolite after 1 wk of storage), and cell survival and transformation were assessed by the colony-forming and focus assays, respectively. X-ray was used as a reference for radiation effects, and 20-methylcholanthrene was used as a positive control for focus formation.


RESULTS
Exposure of cells to 99mTc-Cardiolite results in a transformation frequency that is not significantly different from that induced by the volume equivalent of decayed 99mTc-Cardiolite. The number of foci per viable cell increases linearly from approximately 0.17 x 10(-4) in the untreated control to 1.7 x 10(-4) at 37 kBq/mL and 30 x 10(-4) at 1100 kBq/mL 99mTc-Cardiolite or its decayed 99mTc-Cardiolite volume equivalent. Furthermore, exposure of cells to low extracellular concentrations of 99mTc-Cardiolite or decayed 99mTc-Cardiolite (cell survival, > or =88%) induces an approximately 20-fold greater number of transformants per viable cell than that observed after 0.5 Gy x-irradiation, a dose that causes the same level of toxicity.


CONCLUSIONS
Radioactive and decayed 99mTc-Cardiolite induce morphological transformation of C3H 10T1/2 cells in vitro. The underlying mechanism does not seem to be related to the radiation effects of decaying 99mTc but to chemical(s) present in the 99mTc-Cardiolite kit.
Walicka
M A
MA
Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115-5729, USA.
Ding
Y
Y
Adelstein
S J
SJ
Kassis
A I
AI
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D002471:Cell Transformation, Neoplastic; D004307:Dose-Response Relationship, Radiation; D008748:Methylcholanthrene / Q000633:toxicity; D051379:Mice; D019275:Radiopharmaceuticals / Q000633:toxicity*; D017256:Technetium Tc 99m Sestamibi / Q000633:toxicity*; D014965:X-Rays
D019275:Radiopharmaceuticals; D008748:Methylcholanthrene; D017256:Technetium Tc 99m Sestamibi