Abstract
Successful 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is dependent on efficient porphyrin synthesis in the inflicted cancer tissue, which is regulated by several enzymes. Irradiation of the tumor excites the light-sensitive porphyrins and results in ROS production and cell death. In this study we investigated the effect of the expression levels of two main enzymes in heme biosynthesis, ALA dehydratase (ALAD) and porphobilinogen deaminase (PBGD), on the capacity of K562 cells to undergo cell death following ALA-PDT. We manipulated PBGD and ALAD expression levels by shRNAs and PBGD overexpressing plasmid. PBGD down-regulation induced an elevation in ALAD activity, while overexpression of PBGD reduced ALAD activity, indicating a novel regulation feedback of PBGD on ALAD activity. This feedback mechanism enabled partial PpIX synthesis under PBGD silencing, whereas ALAD silencing reduced PpIX production to a minimum. ALA-PDT efficacy was directly correlated to PpIX levels. Thus, only ALAD-silenced cells were not affected by ALA+ irradiation, while following PBGD silencing, the accumulated PpIX, though decreased, was sufficient for successful ALA-PDT. The alterations in ALAD activity level initiated by changes in PBGD expression indicates PBGD’s central role in heme synthesis. This enables efficient ALA-PDT, even when PBGD is not fully active. Conversely, ALAD loss resulted in reduced PpIX synthesis and consequently failure in ALA-PDT, due to the absence of compensation mechanism for ALAD.
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R. S. Ajioka, J. D. Phillips and J. P. Kushner, Biosynthesis of heme in mammals, Biochim. Biophys. Acta, Mol. Cell Res., 2006, 1763, 723–36.
P. Ponka, Tissue-specific regulation of iron metabolism and heme synthesis: distinct control mechanisms in erythroid cells, Blood, 1997, 89, 1–25.
G. Berkovitch, D. Doron, A. Nudelman, Z. Malik and A. Rephaeli, Novel multifunctional acyloxyalkyl ester prodrugs of 5-aminolevulinic acid display improved anticancer activity independent and dependent on photoactivation, J. Med. Chem., 2008, 51, 7356–69.
P. Hinnen et al., Biochemical basis of 5-aminolaevulinic acid-induced protoporphyrin IX accumulation: a study in patients with (pre)malignant lesions of the oesophagus, Br. J. Cancer, 1998, 78, 679–82.
A. Klein, P. Babilas, S. Karrer, M. Landthaler and R. M. Szeimies, Photodynamic therapy in dermatology-an update 2008, J. Dtsch. Dermatol. Ges., 2008, 6, 839–46.
Q. Peng et al., 5-Aminolevulinic acid-based photodynamic therapy. Clinical research and future challenges, Cancer, 1997, 79, 2282–308.
L. Greenbaum, Y. Gozlan, D. Schwartz, D. J. Katcoff and Z. Malik, Nuclear distribution of porphobilinogen deaminase (PBGD) in glioma cells: a regulatory role in cancer transformation?, Br. J. Cancer, 2002, 86, 1006–11.
T. Feuerstein, A. Schauder and Z. Malik, Silencing of ALA dehydratase affects ALA-photodynamic therapy efficacy in K562 erythroleukemic cells, Photochem. Photobiol. Sci., 2009, 8, 1461–66.
S. Collaud, A. Juzeniene, J. Moan and N. Lange, On the selectivity of 5-aminolevulinic acid-induced protoporphyrin IX formation, Curr. Med. Chem.: Anti-Cancer Agents, 2004, 4, 301–16.
Z. Malik and H. Lugaci, Destruction of erythroleukaemic cells by photoactivation of endogenous porphyrins, Br. J. Cancer, 1987, 56, 589–95.
S. D. Ickowicz, Y. Gozlan, L. Greenbaum, T. Babushkina, D. J. Katcoff and Z. Malik, Differentiation-dependent photodynamic therapy regulated by porphobilinogen deaminase in B16 melanoma, Br. J. Cancer, 2004, 90, 1833–41.
S. L. Gibson, D. J. Cupriks, J. J. Havens, M. L. Nguyen and R. Hilf, A regulatory role for porphobilinogen deaminase (PBGD) in delta-aminolaevulinic acid (delta-ALA)-induced photosensitization?, Br. J. Cancer, 1998, 77, 235–42.
L. Leibovici et al., Activity of porphobilinogen deaminase in peripheral blood mononuclear cells of patients with metastatic cancer, Cancer, 1988, 62, 2297–300.
R. Mamet, L. Leibovici, Y. Teitz and N. Schoenfeld, Accelerated heme synthesis and degradation in transformed fibroblasts, Biochem. Med. Metab. Biol., 1990, 44, 175–80.
N. Schoenfeld, O. Epstein, M. Lahav, R. Mamet, M. Shaklai and A. Atsmon, The heme biosynthetic pathway in lymphocytes of patients with malignant lymphoproliferative disorders, Cancer Lett., 1988, 43, 43–48.
R. Hilf, J. J. Havens and S. L. Gibson, Effect of delta-aminolevulinic acid on protoporphyrin IX accumulation in tumor cells transfected with plasmids containing porphobilinogen deaminase DNA, Photochem. Photobiol., 1999, 70, 334–40.
U. A. Meyer, M. M. Schuurmans and R. L. Lindberg, Acute porphyrias: pathogenesis of neurological manifestations, Semin. Liver Dis., 2008, 18, 43–52.
H. Puy, L. Gouya and J. C. Deybach, Porphyrias, Lancet, 2010, 375, 924–37.
E. Buytaert, M. Dewaele and P. Agostinis, Molecular effectors of multiple cell death pathways initiated by photodynamic therapy, Biochim. Biophys. Acta, 2007, 1776, 86–107.
N. Grunberg-Etkovitz, L. Greenbaum, B. Grinblat and Z. Malik, Proteasomal degradation regulates expression of porphobilinogen deaminase (PBGD) mutants of acute intermittent porphyria, Biochim. Biophys. Acta, 2006, 1762, 819–27.
M. M. Bradford, A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding, Anal. Biochem., 1976, 72, 248–54.
B. Grinblat, N. Pour and Z. Malik, Regulation of porphyrin synthesis and photodynamic therapy in heavy metal intoxication, J. Environ. Pathol. Toxicol. Oncol., 2006, 25, 145–58.
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Schauder, A., Feuerstein, T. & Malik, Z. The centrality of PBGD expression levels on ALA-PDT efficacy. Photochem Photobiol Sci 10, 1310–1317 (2011). https://doi.org/10.1039/c1pp05085k
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DOI: https://doi.org/10.1039/c1pp05085k