title: A decrease in cellular microRNA-27a content is involved in azacytidine-induced P-glycoprotein expression in SKM-1 cells.
abstract: We established an azacytidine (AzaC)-resistant human acute myeloid leukemia (AML) cell line (SKM-1/AzaC) by culturing SKM-1 cells in the presence of increasing amounts of AzaC for six months. Because AzaC is not a substrate of P-glycoprotein (a product of the ABCB1 gene; ABCB1), ABCB1 was not responsible for AzaC resistance; nevertheless, it was notably upregulated in SKM-1/AzaC cells. In addition, the transcription of the Nfkb1 gene, which encodes a member of the canonical NF-kappaB regulatory pathway, was downregulated, and the transcription of the Nfkb2 gene, which encodes a member of the non-canonical NF-kappaB regulatory pathway, was upregulated in SKM-1/AzaC cells. Here, we investigate whether miRNA-27a and miRNA-138 (both of which are known to be regulators of ABCB1 expression) are involved in the regulation of ABCB1 expression in SKM-1/AzaC cells. We observed decreased levels of miRNA-27a but of not miRNA-138 in SKM-1/AzaC cells compared with SKM-1 cells. The transfection of SKM-1/AzaC cells with a miRNA-27a mimic induced the downregulation of the ABCB1 mRNA. This was associated with an increase in Nfkb1 and a decrease in Nfkb2 transcript levels in SKM-1/AzaC cells. Taken together, these data indicate that the downregulation of miRNA-27a is involved in the upregulation of ABCB1 expression in SKM-1/AzaC cells, and this effect is associated with a switch between the canonical and non-canonical NF-kappaB pathways.
authors.affiliation: Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, 812 37 Bratislava, Slovakia; Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia.
authors.forename: Lucia
authors.initials: L
authors.lastname: Messingerova
authors.affiliation: Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia.
authors.forename: Denisa
authors.initials: D
authors.lastname: Imrichova
authors.affiliation: Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia.
authors.forename: Helena
authors.initials: H
authors.lastname: Kavcova
authors.affiliation: Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia.
authors.forename: Mario
authors.initials: M
authors.lastname: Seres
authors.affiliation: Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia. Electronic address: zdena.sulova@savba.sk.
authors.forename: Zdena
authors.initials: Z
authors.lastname: Sulova
authors.affiliation: Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, 812 37 Bratislava, Slovakia; Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravska cesta 9, 840 05 Bratislava, Slovakia. Electronic address: albert.breier@stuba.sk.
authors.forename: Albert
authors.initials: A
authors.lastname: Breier
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000378:metabolism; D000970:Antineoplastic Agents / Q000633:toxicity*; D001374:Azacitidine / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000633:toxicity; D004317:Doxorubicin / Q000633:toxicity; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D063268:Sialic Acid Binding Ig-like Lectin 3 / Q000378:metabolism; D014750:Vincristine / Q000633:toxicity
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D000970:Antineoplastic Agents; C571163:CD33 protein, human; C531388:MIRN27 microRNA, human; D035683:MicroRNAs; D063268:Sialic Acid Binding Ig-like Lectin 3; D014750:Vincristine; D004317:Doxorubicin; D001374:Azacitidine; D002945:Cisplatin
keywords: AML cell line SKM-1; Azacytidine; Multidrug resistance; NF-κB; P-glycoprotein; miRNA-27a