Uptake and retention of Photofrin by cultivated human lymphoblastic cells (Reh6): preferential affinity of the cells for a minor component demonstrated by normal phase chromatography.
The uptake of Photofrin by the human cultivated lymphoblastic cell line Reh6 was studied using normal phase high performance liquid chromatography (HPLC) techniques. Relative cellular uptake of eight fractions (uptake/amount of component initially present in the incubation solution) was determined. After 4 h of incubation, protoporphyrin and a small fraction (denoted 4) were incorporated to a greater relative extent than the other fractions. Weakly incorporated components (hematoporphyrin and aggregate-like components) were better retained by cells than the hydrophobic monomeric porphyrins (protoporphyrin and hydroxyethylvinyldeuteroporphyrin). Thus, any benefit gained from a higher uptake was mostly cancelled by a fast release--a situation observed for all fractions except for fraction 4, which displayed both high uptake and good cellular retention. This pattern was not modified when Photofrin concentration or serum percentage was changed. Fraction 4 was further resolved using a gradient system on normal silica. A single component appeared to be mostly responsible for the favorable properties presented by fraction 4, i.e. high uptake and retention within cells. This component was found to correspond to a late eluted peak in the typical reverse-phase HPLC profile of Photofrin. These results emphasize the possible role of minor Photofrin components.
Dellinger
M
M
Laboratoire de Biophysique, INSERM U. 201, Muséum National d'Histoire Naturelle, Paris, France.
Brault
D
D
D000970:Antineoplastic Agents / Q000378:metabolism*; D001692:Biological Transport; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D017324:Hematoporphyrin Derivative; D006415:Hematoporphyrins / Q000378:metabolism*; D006801:Humans; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma
D000970:Antineoplastic Agents; D006415:Hematoporphyrins; D017324:Hematoporphyrin Derivative