Chapter 8 Basic principles of 5-aminolevulinic acid-based photodynamic therapy

Berg, Kristian

doi:10.1016/s1568-461x(01)80112-5

Cited by 7 publications

(6 citation statements)

References 303 publications

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“…During de-excitation, PpIX may generate O 2 - and ∙OH, as suggested in previous study (Takahashi & Misawa 2009 ). Therefore, the primary sites of action of ALA-PDT may be restricted to the sites of PpIX production and/or accumulation; many studies have described the localization and yield of PpIX in many tumor types (Berg 2001 ; Herman et al 1997 ). However, these studies addressed only tumors of the skin or within the penetration depth of a given light source.…”

Section: Resultsmentioning

confidence: 99%

5-Aminolevulinic acid enhances cancer radiotherapy in a mouse tumor model

et al. 2013

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5-Aminolevulinic acid (ALA) is a photosensitizer used in photodynamic therapy (PDT) because it causes preferential accumulation of protoporphyrin IX (PpIX) in tumor cells, where it forms singlet oxygen upon light irradiation and kills the tumor cells. Our previous study demonstrated that PpIX enhances generation of reactive oxygen species by physicochemical interaction with X-rays. We investigated the effect of ALA administration with X-ray irradiation of mouse B16-BL6 melanoma cells in vitro and in vivo. ALA facilitates PpIX accumulation in tumor cells and enhances ROS generation in vitro. Tumor suppression significantly improved in animals treated with fractionated doses of radiation (3 Gy × 10; total, 30 Gy) with local administration of 50 mg/kg ALA at 24 h prior to fractional irradiation. These results suggest ALA may improve the efficacy of cancer radiotherapy by acting as a radiomediator.

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Section: Resultsmentioning

confidence: 99%

5-Aminolevulinic acid enhances cancer radiotherapy in a mouse tumor model

et al. 2013

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“…, unpublished data)] for reasons that are not fully clear, but involves changes in the activities of the enzymes in the heme synthetic pathway and increased penetration through surface layers covering tumours (e.g. reduced stratum corneum) (Stefanidou et al ., 2000; Berg, 2001; Peng et al ., 2001). The use of 5‐ALA hexyl ester for detection of bladder cancer (papilloma and carcinoma‐in‐situ) has recently been approved in Sweden (Table 1) and the method may be utilized for diagnosis of other indications, such as in the gastrointestinal tractus (Endlicher et al ., 2001; Mayinger et al ., 2001; Claydon & Ackroyd, 2004).…”

Section: Utilization Of Photosensitizers In Diagnosismentioning

confidence: 99%

“…Endogenously synthesized photosensitizers. 5‐Aminolevulinic acid (5‐ALA) is a prodrug for application in PDT and FD that has attracted great attention the last 15 years (Peng et al ., 1997a, b; Berg, 2001; Kormeili et al ., 2004; Lopez et al ., 2004). This treatment is based on heme synthesis.…”

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confidence: 99%

Porphyrin‐related photosensitizers for cancer imaging and therapeutic applications

Berg¹,

Selbo²,

Weyergang³

et al. 2005

Journal of Microscopy

248

176

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SummaryA photosensitizer is defined as a chemical entity, which upon absorption of light induces a chemical or physical alteration of another chemical entity. Some photosensitizers are utilized therapeutically such as in photodynamic therapy (PDT) and for diagnosis of cancer (fluorescence diagnosis, FD). PDT is approved for several cancer indications and FD has recently been approved for diagnosis of bladder cancer. The photosensitizers used are in most cases based on the porphyrin structure. These photosensitizers generally accumulate in cancer tissues to a higher extent than in the surrounding tissues and their fluorescing properties may be utilized for cancer detection. The photosensitizers may be chemically synthesized or induced endogenously by an intermediate in heme synthesis, 5-aminolevulinic acid (5-ALA) or 5-ALA esters. The therapeutic effect is based on the formation of reactive oxygen species (ROS) upon activation of the photosensitizer by light. Singlet oxygen is assumed to be the most important ROS for the therapeutic outcome. The fluorescing properties of the photosenisitizers can be used to evaluate their intracellular localization and treatment effects. Some photosensitizers localize intracellularly in endocytic vesicles and upon light exposure induce a release of the contents of these vesicles, including externally added macromolecules, into the cytosol. This is the basis for a novel method for macromolecule activation, named photochemical internalization (PCI). PCI has been shown to potentiate the biological activity of a large variety of macromolecules and other molecules that do not readily penetrate the plasma membrane, including type I ribosome-inactivating proteins, immunotoxins, gene-encoding plasmids, adenovirus, peptide-nucleic acids and the chemotherapeutic drug bleomycin. The background and present status of PDT, FD and PCI are reviewed.

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“…Although the light absorption of protoporphyrin IX is not optimal for excitation by coelenterazine-chemiluminescence ((ε) = 30 500 ± 2000 M −1 cm −1 , depending on the microscopic pH), 38 we have established that sufficient light is absorbed by the singlet oxygen sensitizer PPIX. 39 In Fig. 9, the absorption coefficients of water, a typical protein (albumin), oxygenated and de-oxygenated haemoglobin and melanin, the dark pigment that is ubiquitous in nature and overexpressed in melanoma cells, 40 are summarized.…”

Section: Discussionmentioning

confidence: 99%

Stem cell-based photodynamic therapy

Shrestha

Seo

Basel

et al. 2012

Photochem Photobiol Sci

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We have transfected murine neural stem cells (NSCs) with a plasmid expressing Gaussia luciferase (gLuc). The enzyme is secreted from the cells. We have used the gLuc-containing supernatant from cultured NSCs to perform in vitro photodynamic therapy of murine melanoma cells (B16F10). The treatment system was comprised of 5-aminolevulinic acid as a prodrug for the synthesis of the 10 photosensitizer protoporphyrin IX, Gaussia luciferase, and its substrate, coelenterazine. A significant reduction in the number of live melanoma cells was observed 36h after coelenterazine-mediated PDT.

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Chapter 8 Basic principles of 5-aminolevulinic acid-based photodynamic therapy

Cited by 7 publications

References 303 publications

5-Aminolevulinic acid enhances cancer radiotherapy in a mouse tumor model

5-Aminolevulinic acid enhances cancer radiotherapy in a mouse tumor model

Porphyrin‐related photosensitizers for cancer imaging and therapeutic applications

Stem cell-based photodynamic therapy

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