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Titolo:
HEPG2 HUMAN HEPATOCARCINOMA CELLS - AN EXPERIMENTAL-MODEL FOR PHOTOSENSITIZATION BY ENDOGENOUS PORPHYRINS
Autore:
VONARXCOINSMAN V; FOULTIER MT; DEBRITO LX; MORLET L; GOUYETTE A; PATRICE T;
Indirizzi:
HOP LAENNEC,DEPT LASER F-44035 NANTES FRANCE HOP LAENNEC,DEPT LASER F-44035 NANTES FRANCE FAC PHARM NANTES F-44035 NANTES FRANCE
Titolo Testata:
Journal of photochemistry and photobiology.B, Biology
fascicolo: 2-3, volume: 30, anno: 1995,
pagine: 201 - 208
SICI:
1011-1344(1995)30:2-3<201:HHHC-A>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
DELTA-AMINOLEVULINIC-ACID; CHINESE-HAMSTER CELLS; HUMAN HEPATOMA-CELLS; PHOTODYNAMIC THERAPY; HEPATOCELLULAR-CARCINOMA; 5-AMINOLEVULINIC ACID; DIMETHYL-SULFOXIDE; PROTOPORPHYRIN-IX; LEUKEMIC-CELLS; HEME-SYNTHESIS;
Keywords:
HEPG2 CELLS; HEPATOCARCINOMA; 5-AMINOLEVULINIC ACID; HEMATOPORPHYRIN DERIVATIVE; PHOTODYNAMIC THERAPY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
48
Recensione:
Indirizzi per estratti:
Citazione:
V. Vonarxcoinsman et al., "HEPG2 HUMAN HEPATOCARCINOMA CELLS - AN EXPERIMENTAL-MODEL FOR PHOTOSENSITIZATION BY ENDOGENOUS PORPHYRINS", Journal of photochemistry and photobiology.B, Biology, 30(2-3), 1995, pp. 201-208

Abstract

Endogenous protoporphyrin IX (PpIX) synthesis after delta-aminolaevulinic acid (ALA) administration occurs in cancer cells in vivo; PpIX, which has a short half-life, may thus constitute a good alternative to haematoporphyrin derivative (KPD) (or Photofrin). This study assesses the ability of the human hepatocarcinoma cell line HepG2 to synthesizePpIX in vitro from exogenous ALA, and compares ALA-induced toxicity and phototoxicity with the photodynamic therapy (PDT) effects of HPD onthis cell line. ALA induced a dose-dependent dark toxicity, with 79% and 66% cell survival for 50 and 100 mu g ml(-1) ALA respectively after 3 h incubation; the same treatment, followed by laser irradiation (lambda = 632 nm, 25 J cm(-2)),induced a dose-dependent phototoxicity, with 54% and 19% cell survival 24 h after PDT. Whatever the incubation time with ALA, a 3 h delay before light exposure was found to be optimal to reach a maximum phototoxicity. HPD induced a slight dose-dependent toxicity in HepG2 cells and a dose- and time-dependent phototoxicity ten times greater than that of ALA-PpIX PDT. After 3 h incubation of2.5 and 5 mu g ml(-1) HPD, followed by laser irradiation (lambda = 632 nm, 25 J cm(-2)), cell survival was 59% and 24% respectively at 24 h. Photoproducts induced by light irradiation of porphyrins absorb light in the red spectral region at longer wavelengths than the original porphyrins. The possible enhancement of PDT effects after HepG2 cell incubation with ALA or HPD was investigated by irradiating cells successively with red Light (lambda = 632 nm) and light (lambda = 650 nm). The total fluence was kept constant at 25 J cm(-2). For both HPD and ALA-PpIX PDT, phototoxicity was lower when cells were irradiated for increased periods with lambda = 650 nm light than with lambda = 632 nm light alone. This suggests that any photoproducts involved either have a short life or are poorly photoreactive. Not all cell lines can synthesize PpIX after ALA incubation. HepG2 cells, which can synthesize enzymes and precursors of endogenous porphyrin synthesis, represent a good in vitro model for experiments using ALA-PpIX PDT. In addition, ALA-PpIX PDT may represent a new, specific treatment for hepatocarcinomas.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 04:47:41