Increased choline uptake in macrophages and prostate cancer cells does not allow for differentiation between benign and malignant prostate pathologies.
Inflammatory cells may contribute to the choline uptake in different prostate pathologies. The aim of this study was (i) to assess if inflammatory cells incorporate choline and (ii) to potentially detect differences compared to FDG uptake. Therefore we investigated the uptake of [(3)H]choline and [(18)F]FDG in human prostate carcinoma cells and human inflammatory cells.



Macrophages were cultured from isolated mononuclear cells, gained by density gradient centrifugation of human buffy coats. T-lymphocytes, B-lymphocytes and granulocytes were enriched by density gradient centrifugation before cell sorting by means of flow cytometry was performed. [(3)H]choline and [(18)F]FDG uptake of isolated inflammatory cells as well as of LNCaP and PC-3 human prostate carcinoma cells was assessed simultaneously in dual tracer uptake experiments.



Macrophages showed highest [(3)H]choline and [(18)F]FDG uptake compared to the tracer uptake rates of leukocytes. [(3)H]choline uptake of macrophages was in the same range as in prostate cancer cells. Lipopolysaccharide stimulation of macrophages resulted in an increase of [(18)F]FDG uptake in macrophages, but not in an increased [(3)H]choline uptake.



The high [(3)H]choline uptake in macrophages may be a source of false-positive PET results in diagnosis of prostate cancer by choline-PET/CT. As already known from FDG-PET, discrimination between tumor and inflammation in prostate cancer patients is not possible via choline-PET.



The application of choline-PET for reliable primary prostate cancer detection and delineation has to be queried.
Department of Nuclear Medicine, Technische Universität München, Munich, Germany; Department of Orthopaedic Surgery, Regensburg University Medical Center, Bad Abbach, Germany.
Timo
T
Schwarz
Department of Nuclear Medicine, Technische Universität München, Munich, Germany; Department of Obstetrics and Gynecology, Technische Universität München, Munich, Germany. Electronic address: christof.seidl@lrz.tum.de.
Christof
C
Seidl
Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany.
Matthias
M
Schiemann
Department of Nuclear Medicine, Technische Universität München, Munich, Germany.
Reingard
R
Senekowitsch-Schmidtke
Department of Nuclear Medicine, Technische Universität München, Munich, Germany; Department of Nuclear Medicine, Universitätsmedizin Rostock, Rostock, Germany.
Bernd Joachim
BJ
Krause
D001692:Biological Transport / Q000187:drug effects; D045744:Cell Line, Tumor; D002794:Choline / Q000378:metabolism*; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*
D008070:Lipopolysaccharides; D019788:Fluorodeoxyglucose F18; D002794:Choline
Inflammatory cells; LNCaP cells; Leucocytes; PC-3 cells; [18F]FDG; [3H]choline