Bioluminescence-activated photodynamic therapy for luciferase transfected, grade 4 astrocytoma cells in vitro.
Bioluminescence activated Photodynamic Therapy
Grade 4 astrocytoma cells
Hypericin
Transfection with luciferase
mTHPC
Journal
Photodiagnosis and photodynamic therapy
ISSN: 1873-1597
Titre abrégé: Photodiagnosis Photodyn Ther
Pays: Netherlands
ID NLM: 101226123
Informations de publication
Date de publication:
Jun 2022
Jun 2022
Historique:
received:
21
01
2022
revised:
31
03
2022
accepted:
04
04
2022
pubmed:
11
4
2022
medline:
9
6
2022
entrez:
10
4
2022
Statut:
ppublish
Résumé
. Grade 4 astrocytoma is incurable due to the diffusely infiltrative nature of the disease. Photodynamic therapy (PDT) is a promising therapeutic option, but external light delivery is not feasible when cancer cells infiltrate unknown areas of normal brain. Hence the search for endogenous sources such as bioluminescence that can generate light at cancer cells. This requires a substrate (a luciferin) and an enabling enzyme (a luciferase), neither seen in mammalian cells. . Preliminary studies confirmed that U87 cells (derived from a human grade 4 astrocytoma) could be killed by conventional PDT using the photosensitizers hypericin or mTHPC. U87 cells were then transfected with firefly and other luciferases and light generating cell lines (U87-luc, U87-hRluc, U87-CBG68luc) identified using the appropriate substrate. Reagent doses and conditions were optimized and U87-luc cells incubated with hypericin or mTHPC with d-luciferin added to initiate bioluminescence activated PDT (bPDT). Cell survival was assessed by MTT assay, haemocytometry and growth assay. Control groups included U87-luc cells with no added active reagents, substrate only, photosensitizer only and non-transfected U87 cells. Results were expressed as a percentage of surviving cells compared with untreated U87-luc controls. . There was no bPDT effect on non-transfected cells. The mean survival of treated transfected cells was 36%, (P<0.001) using hypericin and 35% (P<0.001) using mTHPC, compared with untreated U87-luc cells. bPDT effects were suppressed by the anti-oxidant, lycopene. . bPDT can kill Grade 4 astrocytoma cells transfected with luciferase in vitro. This justifies progression to in vivo studies.
Sections du résumé
BACKGROUND
BACKGROUND
. Grade 4 astrocytoma is incurable due to the diffusely infiltrative nature of the disease. Photodynamic therapy (PDT) is a promising therapeutic option, but external light delivery is not feasible when cancer cells infiltrate unknown areas of normal brain. Hence the search for endogenous sources such as bioluminescence that can generate light at cancer cells. This requires a substrate (a luciferin) and an enabling enzyme (a luciferase), neither seen in mammalian cells.
METHODS
METHODS
. Preliminary studies confirmed that U87 cells (derived from a human grade 4 astrocytoma) could be killed by conventional PDT using the photosensitizers hypericin or mTHPC. U87 cells were then transfected with firefly and other luciferases and light generating cell lines (U87-luc, U87-hRluc, U87-CBG68luc) identified using the appropriate substrate. Reagent doses and conditions were optimized and U87-luc cells incubated with hypericin or mTHPC with d-luciferin added to initiate bioluminescence activated PDT (bPDT). Cell survival was assessed by MTT assay, haemocytometry and growth assay. Control groups included U87-luc cells with no added active reagents, substrate only, photosensitizer only and non-transfected U87 cells. Results were expressed as a percentage of surviving cells compared with untreated U87-luc controls.
RESULTS
RESULTS
. There was no bPDT effect on non-transfected cells. The mean survival of treated transfected cells was 36%, (P<0.001) using hypericin and 35% (P<0.001) using mTHPC, compared with untreated U87-luc cells. bPDT effects were suppressed by the anti-oxidant, lycopene.
CONCLUSIONS
CONCLUSIONS
. bPDT can kill Grade 4 astrocytoma cells transfected with luciferase in vitro. This justifies progression to in vivo studies.
Identifiants
pubmed: 35398261
pii: S1572-1000(22)00144-2
doi: 10.1016/j.pdpdt.2022.102856
pii:
doi:
Substances chimiques
Photosensitizing Agents
0
Luciferases
EC 1.13.12.-
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
102856Informations de copyright
Copyright © 2022. Published by Elsevier B.V.