Novel potential photodynamic therapy strategy using 5-Aminolevulinic acid for ovarian clear-cell carcinoma.

Abstract

BACKGROUND:

Photodynamic therapy (PDT) is known as a minimally invasive treatment for cancer. 5-Aminolevulinic acid (ALA) is a precursor of the photosensitizing agent protoporphyrin IX (PpIX). Patients with ovarian clear-cell carcinoma (CCC) have poorer prognoses than those of patients with other histological CCC types. We evaluated the efficacy of ALA-PDT on CCC cells in vitro.

METHODS:

We used seven human CCC cell lines to measure the cytotoxicity of ALA-PDT. PpIX production in cancer cells was measured using a micro-plate reader. Quantitative real-time PCR was performed to assess the mRNA levels of genes involved in the accumulation of PpIX in cancer cells. Additionally, we measured the enhancement in cytotoxicity with the use of an ABCG2 inhibitor.

RESULTS:

We found that three cell lines were highly sensitive to ALA-PDT. In contrast, one cell line was resistant to ALA-PDT. The cytotoxicity of ALA-PDT varied among CCC cell lines. The IC50 values of ALA-PDT for the CCC cell lines had a wide range (30-882μM). The cytotoxicity of ALA-PDT was correlated with the intracellular PpIX accumulation. The cell lines sensitive to ALA-PDT expressed PEPT1 (an ALA uptake transporter). The cell line resistant to ALA-PDT expressed ABCG2 (a PpIX export transporter). In the resistant cell line, a combination treatment with both ALA and an ABCG2 inhibitor resulted in the promotion of cytotoxic sensitivity.

CONCLUSION:

The present study revealed the efficacy of ALA-PDT against CCC with chemoresistance in vitro.

• Authors: Toshiya Teshigawara, Mika Mizuno, Takuya Ishii, Yuya Kitajima, Fumi Utsumi, Jun Sakata, Hiroaki Kajiyama, Kiyosumi Shibata, Masahiro Ishizuka, Fumitaka Kikkawa
• Journal: Photodiagnosis and photodynamic therapy (Photodiagnosis Photodyn Ther) Vol. 21 Pg. 121-127 (Mar 2018) ISSN: 1873-1597 [Electronic] Netherlands
• PMID: 29196245 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical References

• ATP Binding Cassette Transporter, Subfamily G, Member 2
• Photosensitizing Agents
• Protoporphyrins
• RNA, Messenger
• Aminolevulinic Acid
• protoporphyrin IX

Topics

• ATP Binding Cassette Transporter, Subfamily G, Member 2 (antagonists & inhibitors)
• Adenocarcinoma, Clear Cell (drug therapy)
• Aminolevulinic Acid (pharmacology)
• Cell Line, Tumor
• Combined Modality Therapy
• Female
• Humans
• Ovarian Neoplasms (drug therapy)
• Photochemotherapy (methods)
• Photosensitizing Agents (pharmacology)
• Protoporphyrins (biosynthesis)
• RNA, Messenger
• Real-Time Polymerase Chain Reaction