title: Novel multifunctional acyloxyalkyl ester prodrugs of 5-aminolevulinic acid display improved anticancer activity independent and dependent on photoactivation.
abstract: Multifunctional acyloxyalkyl ester prodrugs of 5-aminolevulinic acid in cancer cell lines inhibited the proteasome and induced apoptosis and heme synthesis. The most potent prodrug was butyryloxymethyl 5-amino-4-oxopentanoate (1a). The metabolically released formaldehyde from the prodrugs was the dominant factor affecting cell viability by a ROS-dependent mechanism and was responsible for rapid phosphorylation of H2AX, suppression of the cell survival protein c-myc, and transient elevation in the expression of p21. 1a, which differs from 2a by releasing butyric instead of pivalic acid, was a more potent inducer of heme and acetylated H4 expression and induced apoptosis through activation of caspase 9. 1a and 1b specifically increased the level of the photosensitizer protoporphyrin 9, leading to enhancement of cell death by photodynamic therapy (PDT). The advantage of these multifunctional prodrugs over 5-ALA is their greater potency in the non-PDT mechanism of cancer cell killing and their ability to also augment PDT.
authors.affiliation: Laboratory of Pharmacology and Experimental Oncology, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, Israel.
authors.forename: Gili
authors.initials: G
authors.lastname: Berkovitch
authors.forename: Dvir
authors.initials: D
authors.lastname: Doron
authors.forename: Abraham
authors.initials: A
authors.lastname: Nudelman
authors.forename: Zvi
authors.initials: Z
authors.lastname: Malik
authors.forename: Ada
authors.initials: A
authors.lastname: Rephaeli
mesh_terms: D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D020148:Butyric Acid / Q000378:metabolism / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D018922:HL-60 Cells; D006418:Heme / Q000378:metabolism; D006657:Histones / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D015394:Molecular Structure; D010766:Phosphorylation; D010777:Photochemistry; D011166:Porphyrins / Q000378:metabolism; D011355:Prodrugs / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D061988:Proteasome Inhibitors; D016271:Proto-Oncogene Proteins c-myc / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; C468783:H2AX protein, human; D006657:Histones; D011166:Porphyrins; D011355:Prodrugs; D061988:Proteasome Inhibitors; D016271:Proto-Oncogene Proteins c-myc; D017382:Reactive Oxygen Species; C539550:butyryloxymethyl 5-amino-4-oxopentanoate; D020148:Butyric Acid; D006418:Heme; D000622:Aminolevulinic Acid