title: Medroxyprogesterone acetate alone or synergistic with chemotherapy suppresses colony formation and DNA synthesis in C6 glioma in vitro.
abstract: We have studied the effects of medroxyprogesterone acetate (MPA) on C6 glioma growth in vitro in order to prove the hypothesis that it could arrest growth and induce drug sensitisation in a glial tumour as it does in breast cancer cells. Plating, thymidine-labelling index, ultra-structure, and soft agar colony growth were determined after incubation with MPA, and/or cisplatin, procarbazine and methotrexate (MTX). MPA (microg/ml) reduced the thymidine-labelling index by 41 and 73% at 48 and 96 h, respectively, and decreased colony growth by 61%. Soft agar colony inhibition by MPA was almost as potent as MTX (0.3 microg/ml), but the latter drug showed very high cytotoxicity. Electron microscopy revealed that in medroxyprogesterone treated cells myeloid bodies developed, but MTX treatment caused mainly necrosis. Medroxyprogesterone increased procarbazine and cisplatin-induced colony growth and S-phase inhibition, but reduced MTX-induced thymidine-labelling inhibition. In conclusion, progesterone may inhibit growth and sensitize to drugs.
authors.affiliation: Histology and Embryology Department, Istanbul Medical School, 34390, Istanbul, Turkey. maltinoz@hotmail.com
authors.forename: M A
authors.initials: MA
authors.lastname: Altinoz
authors.forename: A
authors.initials: A
authors.lastname: Bilir
authors.forename: E
authors.initials: E
authors.lastname: Ozar
authors.forename: F D
authors.initials: FD
authors.lastname: Onar
authors.forename: A
authors.initials: A
authors.lastname: Sav
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects* / Q000502:physiology; D002945:Cisplatin / Q000633:toxicity; D004247:DNA / Q000187:drug effects* / Q000378:metabolism; D004357:Drug Synergism; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008525:Medroxyprogesterone / Q000627:therapeutic use / Q000633:toxicity*; D008727:Methotrexate / Q000633:toxicity; D008854:Microscopy, Electron; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology*; D011344:Procarbazine / Q000633:toxicity; D045167:Progesterone Congeners / Q000627:therapeutic use / Q000633:toxicity*; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay
chemical_list: D000970:Antineoplastic Agents; D019384:Nucleic Acid Synthesis Inhibitors; D045167:Progesterone Congeners; D011344:Procarbazine; D004247:DNA; D008525:Medroxyprogesterone; D002945:Cisplatin; D008727:Methotrexate