title: MNU-induced mammary gland carcinogenesis: chemopreventive and therapeutic effects of vitamin D and Seocalcitol on selected regulatory vitamin D receptor pathways.
abstract: The effects of administration of vitamin D₃ and Seocalcitol on MNU-induced carcinogenesis of mammary gland in Sprague-Dawley rats have been investigated. Administration of both substances in a weekly dose of 7 μg/kg caused prolonged latency of mammary gland tumors. The latency of tumors was markedly prolonged for 30-40 days by Seocalcitol. Using PET analysis, reduction in [¹⁸F]2-fluoro-2-deoxy-d-glucose (FDG) uptake or tumor volume in tumors chemopreventively treated with vitamin D₃ were detected in MNU-induced tumors, vitamin D₃ reduced expression of 25-hydroxylase (25OHase) (p<0.01) and 24-hydroxylase (24OHase) (p<0.01) and Seocalcitol 24OHase. Positive regulation of 25OHase mRNA level after the treatment with vitamin D₃ was observed in liver, while in kidney, vitamin D₃ and Seocalcitol induced expression of 24OHase was significant. Our observations indicate a cross talk between respective pathways of VDR, RARs/RXRs, TRs and ERs in carcinogenesis process.
authors.affiliation: Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlárska 3, 83306 Bratislava, Slovak Republic. ueenmace@savba.sk
authors.forename: Dana
authors.initials: D
authors.lastname: Macejová
authors.forename: Slavomíra
authors.initials: S
authors.lastname: Ondková
authors.forename: Lucia
authors.initials: L
authors.lastname: Jakubíková
authors.forename: Alžbeta
authors.initials: A
authors.lastname: Mlynarčíková
authors.forename: Soňa
authors.initials: S
authors.lastname: Scsuková
authors.forename: Ján
authors.initials: J
authors.lastname: Liška
authors.forename: Július
authors.initials: J
authors.lastname: Brtko
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced / Q000187:drug effects*; D002762:Cholecalciferol / Q000494:pharmacology*; D005260:Female; D006651:Histocytochemistry; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced* / Q000201:enzymology / Q000378:metabolism / Q000517:prevention & control*; D008770:Methylnitrosourea / Q000633:toxicity; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D049268:Positron-Emission Tomography; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D018167:Receptors, Calcitriol; D002762:Cholecalciferol; D008770:Methylnitrosourea; D006899:Mixed Function Oxygenases; D002117:Calcitriol; C078903:seocalcitol