Conclusions
The results showed that CFA preferentially accumulated in cancer cells rather than in normal cells. These findings suggest that CFA may be a potential diagnostic probe for discriminating healthy tissues from malignant tissues due to its specific and highly sensitive features; CFA may also represent a useful tool for in vitro/ex vivo investigations of choline metabolism in patients with cervical and breast cancers.
Methods
CFA was fully characterised and tested for its cytotoxicity on breast (MCF-7), cervical (HeLa), glioblastoma (U-87 MG) and hepatoblastoma (HepG2) cancer cell lines and in normal cell lines (epithelial, HEK-293 and human dermal fibroblasts, HDFs). The cellular uptake of CFA was investigated by a confocal microscope and its accumulation was quantified over time. The specificity of CFA over mesenchymal origin cells (HDFs), as a model of cancer-associated fibroblasts was investigated by fluorescence microscopy.
Results
CFA was toxic at much higher concentrations (HeLa IC50 = 200 ± 18 µM and MCF-7 IC50 = 105 ± 3 µM) than needed for its detection in cancer cells (5 µM). CFA was not toxic in the other cell lines tested. The intensity of CFA in breast and cervical cancer cells was not significantly different at any time point, yet it was greater than HepG2 and U-87 MG (p ≤ 0.01 and p ≤ 0.0001, respectively) after 24 h incubation. A very weak signal intensity was recorded in HEK-293 and HDFs (p ≤ 0.001 and p ≤ 0.0001, respectively). A selective ability of CFA to accumulate in HeLa and MCF-7 was recorded upon co-culture with fibroblasts. Conclusions: The results showed that CFA preferentially accumulated in cancer cells rather than in normal cells. These findings suggest that CFA may be a potential diagnostic probe for discriminating healthy tissues from malignant tissues due to its specific and highly sensitive features; CFA may also represent a useful tool for in vitro/ex vivo investigations of choline metabolism in patients with cervical and breast cancers.