title: Photodynamic effect in medulloblastoma: downregulation of matrix metalloproteinases and human telomerase reverse transcriptase expressions.
abstract: Tumor invasion and immortality are the most unfavorable drawbacks after cancer treatment. In this study, we focus on determining the photodynamic modulation of the proteolytic enzymes, matrix metalloproteinases (MMP); and a core catalytic subunit of telomerase, the human telomerase reverse transcriptase (hTERT) in medulloblastoma (MED) cell line (TE-671). Hexvix (ALA-H) mediated photodynamic therapy (PDT) demonstrated greater efficacy than 5-aminolevulinic acid (5-ALA) in terms of drug uptake and anti-proliferative effect. Both MMP-2 and hTERT expression are down-regulated quantitatively using ELISA and reverse-transcriptase-PCR (RT-PCR) respectively at post-treatment for this cell line. The MMP-9 expression remains unchanged after treatment. Further, there is a statistically significant inhibition of cell migration at 24 h post-ALA-H-PDT at LD(50) (0.01 mM, 2 J cm(-2); p < 0.001) in MED TE-671 cells. Evidently, MMP-2 and hTERT mRNA expressions can be the targets for the photodynamic intervention on tumor cell migration and immortality. Hence, PDT may be an alternate cancer regime for medulloblastoma.
authors.affiliation: Medical Laboratory Science, Department of Health Technology & Informatics, The Hong Kong Polytechnic University, HKSAR.
authors.forename: Ellie Shihng Meir
authors.initials: ES
authors.lastname: Chu
authors.forename: Thomas Kwok Shing
authors.initials: TK
authors.lastname: Wong
authors.forename: Christine Miu Ngan
authors.initials: CM
authors.lastname: Yow
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement; D015536:Down-Regulation / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D008527:Medulloblastoma / Q000188:drug therapy* / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D010778:Photochemotherapy; D011166:Porphyrins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*
chemical_list: D011166:Porphyrins; D012333:RNA, Messenger; C509186:TERT protein, human; D019098:Telomerase; D020782:Matrix Metalloproteinases