Effects of vitamin D and retinoic acid on human glioblastoma cell lines.
The biological significance of vitamin D receptors expressed by glioblastoma and other glial tumours is still unclear. In an effort to clarify this issue we studied the effects of increasing concentrations of 25-dihydroxyvitamin D3 and its metabolite 1 alpha,25-dihydroxyvitamin D3 on two human glioblastoma cell lines. Both substances were capable of inducing a significant (> 50%) reduction in growth of the two glioblastoma cell lines at dosages over 5 microM. When the HU 70 cell line was treated by increasing dilutions of 25-dihydroxyvitamin D3 combined with 1 microM all trans-retinoic acid, significant inhibition was apparent even after addition of 25-dihydroxyvitamin D3 in the nanomolar range. Reduction of growth index was mainly due to induced cell death. Our results provide in vitro evidence that vitamin D metabolites alone or in combination with retinoids may be potentially useful agents in the differentiation therapy of human malignant gliomas.
Magrassi
L
L
Department of Surgery, University of Pavia, IRCCS Policlinico S. Mattco, Italy.
Butti
G
G
Pezzotta
S
S
Infuso
L
L
Milanesi
G
G
D001932:Brain Neoplasms / Q000473:pathology*; D002117:Calcitriol / Q000494:pharmacology*; D002460:Cell Line; D002762:Cholecalciferol / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects*
D002762:Cholecalciferol; D014212:Tretinoin; D002117:Calcitriol