title: Cisplatin induces radioprotection in human T98G glioma cells.
abstract: Malignant gliomas are often treated with cisplatin (cis-diamminedichloroplatinum(II), CDDP) and radiation but results remain unsatisfactory. To investigate whether CDDP induces radioresistance in glioma, T98G human glioblastoma cells were pretreated 5 times with 10(-6)M CDDP for 24 hours and then the sensitivity of wild type (wt) and pretreated cells towards radiation (9Gy 60Co) and CDDP was tested in a colorimetric assay (MIT). The growth rates of wt and pretreated cells were 1.8 +/-0.2 and 3.1 +/- 0.2 respectively (p = 0.000155) 216 hours post radiation. Pretreated cells also developed resistance to CDDP (resistance factor 2.35). Glutathione (GSH) which potentially mediates resistance to both treatments was measured. Incubation for 6 hours with 10(-5) M CDDP increased GSH levels by a factor of 2.28 (p < 0.0001). However, neither basal nor increased levels differed between wt and pretreated cells. These data show that CDDP pretreatment can induce resistance against radiation and CDDP independently of GSH.
authors.affiliation: Department of Paediatric Haematology and Oncology, University Hospital of Munster, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Poppenborg
authors.forename: G
authors.initials: G
authors.lastname: Münstermann
authors.forename: M M
authors.initials: MM
authors.lastname: Knüpfer
authors.forename: M
authors.initials: M
authors.lastname: Hotfilder
authors.forename: U
authors.initials: U
authors.lastname: Hacker-Klom
authors.forename: J E
authors.initials: JE
authors.lastname: Wolff
mesh_terms: D002945:Cisplatin / Q000494:pharmacology*; D005910:Glioma / Q000378:metabolism / Q000532:radiotherapy*; D005978:Glutathione / Q000032:analysis; D006801:Humans; D011836:Radiation Tolerance / Q000187:drug effects*; D014407:Tumor Cells, Cultured
chemical_list: D005978:Glutathione; D002945:Cisplatin