Cited by 140Photodynamic Therapy Research StudiesPorphyrin Metabolism and DisordersPorphyrin and Phthalocyanine Chemistry

Differential interaction of porphyrins used in photoradiation therapy with ferrochelatase

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Dailey, H A, Smith, A·1984·Biochemical Journal

Abstract

The mechanism of porphyrin accumulation by tumours is not yet established. If metabolism aids porphyrin elimination, tumours, unlike normal tissues, may not metabolize porphyrins used clinically, such as proto-, haemato-, OO'-diacetyl-haemato- and monohydroxyethyl-monovinyl-deutero-porphyrin. Proto-, haemato- and monohydroxyethyl-monovinyl-deutero-porphyrin are substrates for the mitochondrial enzyme ferrochelatase (EC 4.99.1.1), which can form haem analogues from exogenous porphyrins. The Km values for proto-, haemato- and monohydroxyethyl-monovinyl-deutero-porphyrin are 11, 22 and 23 microM respectively. However, OO'-diacetyl-haematoporphyrin is an effective competitive inhibitor with Ki of 11 microM. Hepatic ferrochelatase specific activity is 5.9 and 5.5 nmol of haem/h per mg of protein respectively in normal Buffalo rat and in those bearing the extrahepatic Morris 7288C hepatoma, and is only 0.13 nmol/h per mg in the hepatomas. Therefore low ferrochelatase activity in cancerous cells may provide one means whereby some porphyrins accumulate in tumours, and the ability of certain porphyrins to act as ferrochelatase inhibitors may provide another.

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  • Although the uptake of ALA is non-selective, accumulation of PpIX in tumor cells may occur selectively because of alterations in enzymatic activity in the heme synthesis pathway.

    “Although the uptake of ALA is non-selective, accumulation of PpIX in tumor cells may occur selectively because of alterations in enzymatic activity in the heme synthesis pathway.”

    From Photodynamic Therapy for Non-Melanoma Skin Cancers (2016) · cites this paper as [10]

  • The accumulation of PpIX in neoplastic tissue is further supplemented by decreased activity of ferrochelatase (FC), which converts PpIX to heme.

    “The accumulation of PpIX in neoplastic tissue is further supplemented by decreased activity of ferrochelatase (FC), which converts PpIX to heme [9,10].”

    From Photodynamic Therapy for Non-Melanoma Skin Cancers (2016) · cites this paper as [10]

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Research works printed but not linked: 3

  1. Bonnett, R., Ridge, R. J., Scourides, P. A. & Berenbaum, M. C. (1981)J. Chem. Soc. Perkin Trans. 1 3135-3140
  2. Friedkin, M. (1973) Fed. Proc. Fed. Am. Soc. Exp. Biol. 32, 2148-2153
  3. Thompson, E. B., Tomkins, G. M. & Curran, J. F. (1966) Proc. Nati. Acad. Sci. U.S.A. 56, 296-304

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Authors
Dailey, H. A., & Smith, A.
Venue
Biochemical Journal
Published
1984-10-15
Volume
223
Issue
2
Pages
441-445
ISSN
  • 0264-6021 (ISSN-L)
  • 1470-8728
OpenAlex
W2170447022
Cited by
140
References
30
Citations by year
2025: 1 · 2023: 1 · 2022: 3 · 2020: 3 · 2019: 3 · 2018: 1 · 2017: 4 · 2016: 3 · 2015: 4 · 2014: 1 · 2012: 3
FWCI
6.75
Type
journal article
Language
en
Open access
Locations
  • Biochemical Journal (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • British Sedimentological Research Group
  • National Institutes of Health
  • U.S. Public Health Service
Topics
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Photodynamic Therapy Research Studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Porphyrin Metabolism and Disorders
  • Physical Sciences › Materials Science › Materials Chemistry › Porphyrin and Phthalocyanine Chemistry
Keywords
porphyrins, ferrochelatase, photodynamic therapy, hematoporphyrin, deuteroporphyrin, competitive inhibition, enzyme kinetics, hepatocellular carcinoma
MeSH terms
Animals, Ferrochelatase, Hematoporphyrins, Kinetics, Liver, Liver Neoplasms, Experimental, Lyases, Male, Porphyrins, Rats, Inbred BUF, Rats, In Vitro Techniques

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