PDT-induced epigenetic changes in the mouse cerebral cortex: a protein microarray study.
BACKGROUND
Photodynamic therapy (PDT) is used for cancer treatment including brain tumors. But the role of epigenetic processes in photodynamic injury of normal brain tissue is unknown.


METHODS
5-Aminolevulinic acid (ALA), a precursor of protoporphyrin IX (PpIX), was used to photosensitize mouse cerebral cortex. PpIX accumulation in cortical tissue was measured spectrofluorometrically. Hematoxylin/eosin, gallocyanin-chromalum and immunohistochemical staining were used to study morphological changes in PDT-treated cerebral cortex. Proteomic antibody microarrays were used to evaluate expression of 112 proteins involved in epigenetic regulation.


RESULTS
ALA administration induced 2.5-fold increase in the PpIX accumulation in the mouse brain cortex compared to untreated mice. Histological study demonstrated PDT-induced injury of some neurons and cortical vessels. ALA-PDT induced dimethylation of histone H3, upregulation of histone deacetylases HDAC-1 and HDAC-11, and DNA methylation-dependent protein Kaiso that suppressed transcriptional activity. Upregulation of HDAC-1 and H3K9me2 was confirmed immunohistochemically. Down-regulation of transcription factor FOXC2, PABP, and hBrm/hsnf2a negatively regulated transcription. Overexpression of phosphorylated histone H2AX indicated activation of DNA repair, but down-regulation of MTA1/MTA1L1 and PML - impairment of DNA repair. Overexpression of arginine methyltransferase PRMT5 correlated with up-regulation of transcription factor E2F4 and importin α5/7.


CONCLUSIONS
ALA-PDT injures and kills some but not all neurons and caused limited microvascular alterations in the mouse cerebral cortex. It alters expression of some proteins involved in epigenetic regulation of transcription, histone modification, DNA repair, nuclear protein import, and proliferation.


CONCLUSIONS
These data indicate epigenetic markers of photo-oxidative injury of normal brain tissue.
Southern Federal University, Rostov-on-Don 344090, Russia. Electronic address: demyanenkosvetlana@gmail.com.
S V
SV
Demyanenko
A B
AB
Uzdensky
S A
SA
Sharifulina
T O
TO
Lapteva
L P
LP
Polyakova
D000622:Aminolevulinic Acid / Q000494:pharmacology*; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D044127:Epigenesis, Genetic / Q000187:drug effects* / Q000235:genetics / Q000528:radiation effects; D057890:Epigenomics; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D006657:Histones / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D040081:Protein Array Analysis; D020543:Proteome / Q000032:analysis*
D006657:Histones; D017319:Photosensitizing Agents; D020543:Proteome; D000622:Aminolevulinic Acid
ALA; ALA-PDT; AP-1/c-Jun; Antibody microarray; BACH1; Brain cortex; CENP-E; E2F transcription factor 4; E2F4; Epigenetic; FOXC2; G9a; H3K9me2; HDAC related protein; HDAC-1, HDAC-10 and HDAC-11; HDRP; MTA1/MTA1L1; N-CoR; PABP; PDT; PML; PRMT5; PpIX; Proteomic; SIR 2; SUV39H1; TXNIP; activation protein transcription factor 1; aminolevulinic acid; breast cancer type1 protein; centromere protein E; chromatin remodeling factor; co-repressor complex; forkhead box C2; hABH1; hBrm/hsnf2a; histone H2AX phosphorylated at serine 139; histone H3 dimethylated at lysine 9; histone deacetylases; histone methyltransferase G9a; human AlkB homolog 1; metastasis-associated protein 1/metastasis tumor associated 1-like 1; photodynamic therapy; poly(A)-binding protein; promyelocytic leukemia; protein arginine methyltransferase 5; protoporphyrin IX; silent information regulator; suppressor of variegation 3-9 homolog 1; thioredoxin-interacting protein; γH2AX