ABSTRACT
Objective To investigate the photodynamic effect induced by laser and use it as a method for purging of minimal residual tumor cells from autologous peripheral blood stem cell grafts. Methods We studied the effect of various concentrations of hematoporphyrin derivative (HPD) combined with of different time of laser irradiation on human leukemia cell line K562, breast tumor cell line MCF-7 and human umbilical cord blood-derived hematopoietic stem/progenitor cells by using MTT assay to compare the photodynamic effect between cell lines of each group. Results HPD or laser irradiation alone had no apparent cytotoxicity while the application of HPD plus laser exposure caused photosensitization. HPD plus laser irradiation was more efficient for killing K562 cells and MCF-7 cells than doing the normal human umbilical cord blood-derived hematopoietic stem/progenitor cells. The photodynamic effect on K562 cells and MCF-7 cells was positively correlated with the increase of treatment duration and HPD concentration. Conclusion These results indicated that the laser photodynamic effect mediated by HPD might be used for purging autologous peripheral blood stem cell grafts in vitro.
ABSTRACT
Fortyfour male Kunming mice, weighing 20-25g. were used. The HpD was injected (10mg/kg) into the caudal vein of 32 mice individually. After 48 hours, the kidneys were radiated directly by the dye-laser for 10 minutes (630nm, 250-300J/cm~2). Then, the kidneys were observed at different times. 12 normal male mice served as control. The experiment demonstrated that when HpD was activated by laser, it could produce the necrotic effect on the renal tissues. The different structures of the kidney showed different susceptibility to HpD-laser. The proximal convoluted tubules and capillaries were injured earlier than the distal convoluted tubules and the collecting tubules. The first morphologic changes observed electron microscopically were the swelling of mitochondria and the formation of vesicles on the cell membrane. Finally, they were completely disrupted. The damages of lysosomes, endoplasmic reticula, ribosomes and cell nucleus followed. The activity of some enzymes in the kidney were inhibited. The sequence of the extents of the enzymes being inhibited was AkP, AcP, Cytox, SDH. The mucopolysaccharides ran off the brush border in proximal convoluted tubules. The results of this study suggested that the various susceptibilities to HpD-laser are chiefly due to the different structures and their functional conditions in the kidney. The main photodynamic effect is presented as the injury of the membrane system of the cell.
ABSTRACT
The uptake and retention of ~3H-HPD in.human malignant cells(cell line MGC 80-3,SGC-7901,BEL-7402,Os-732,Detroit-6 and HeLa)and normal fibroblasts were studied by liquid scintillation counting method.The order of cell lines which took up ~3H-HPD after 30 min.incubation were fibroblasts,HeLa, BEL-7402,Detroit-6,SGC-7901,MGC 80-3 and Os-732 respectively according to the amount of ~3H-HPD in cells.Due to the variety in the amount of excretion, however,those cells which retained ~3H-HPD after 24 hours cultivation were Os-732, Detroit-6, BEL-7402,HeLa,SGC-7901,MGC 80-3 and fibroblasts respectively in respect to the ~3H-HPD level in cells.The uptake was reduced by raising extracel- lular pH and lowering temperature as well as adding higher concentration of serum. Our results showed that the ~3H-HPD content in malignant ceils was higher than those in normal ones and it was because that malignant cells retained ~3H-HPD longer other than took up more