title: In vitro and in vivo matrix metalloproteinase expression after photodynamic therapy with a liposomal formulation of aminolevulinic acid and its methyl ester.
abstract: Photodynamic therapy (PDT) is a well-known method for the treatment of malignant tumors, and its principles have been well established over the past 30 years. This therapy involves the application of a chemical called a photosensitizer and its subsequent excitation with light at the appropriate wavelength and energy. Topical photodynamic therapy with aminolevulinic acid (5-ALA) is an alternative therapy for many malignant processes, including nonmelanoma skin cancers such as basal-cell carcinoma (BCC). Our novel approach for this study was to use a liposomal formulation of 5-ALA and its methyl ester (commercially available as metvix) both in vitro and in vivo, and to check whether the liposome-entrapped precursors of photosensitizers can induce the expression of metalloproteinases (MMPs) in animal tumor cells and in other tissues from tumor-bearing rats and in selected cell lines in vitro. We also checked whether the application of tissue inhibitors of matrix metalloproteinases (TIMPs) has any effect on MMPs in the above-mentioned experimental models, and if they can cause complete inhibition of MMP expression. Immunohistochemical studies revealed that after the PDT, the intensity of expression of MMPs in healthy animals was very low and seen in single cells only. After the PDT in tumor-bearing rats, MMP-3 was expressed in the tumor cells with the highest intensity of staining in the tissues directly adjacent to the tumors, while MMP-2 and -9 were not found. In the control groups, there was no observed expression of MMPs. In vitro studies showed that MMP-3 was expressed in MCF-7 cells after PDT, but MMP-9 was not observed and MMP-2 was only seen in single cases. Our studies confirmed that the application of an MMP-3 inhibitor may block an induction of MMP-3 expression which had previously been initiated by PDT. The preliminary data obtained from cancer patients revealed that new precursors are effective in terms of PDT, and that using MMP inhibitors should be considered as a potential enhancing factor in clinical PDT.
authors.affiliation: Department of Pathology, Wrocław Medical University, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Osiecka
authors.forename: Kamil
authors.initials: K
authors.lastname: Jurczyszyn
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Symonowicz
authors.forename: Andrzej
authors.initials: A
authors.lastname: Bronowicz
authors.forename: Paweł
authors.initials: P
authors.lastname: Ostasiewicz
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Czapińska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Hotowy
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Krzystek-Korpacka
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Gebarowska
authors.forename: Ilona
authors.initials: I
authors.lastname: Izykowska
authors.forename: Piotr
authors.initials: P
authors.lastname: Dziegiel
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Terlecki
authors.forename: Piotr
authors.initials: P
authors.lastname: Ziółkowski
mesh_terms: D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001943:Breast Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000532:radiotherapy; D045744:Cell Line, Tumor / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000627:therapeutic use; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
chemical_list: D007527:Isoenzymes; D008081:Liposomes; D017319:Photosensitizing Agents; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid; D020782:Matrix Metalloproteinases