title: miRNA array screening reveals cooperative MGMT-regulation between miR-181d-5p and miR-409-3p in glioblastoma.
abstract: The levels of expression of O6-methylguanine-DNA methyltransferase (MGMT) are relevant in predicting the response to the alkylating chemotherapy in patients affected by glioblastoma. MGMT promoter methylation and the published MGMT regulating microRNAs (miRNAs) do not completely explain the expression pattern of MGMT in clinical glioblastoma specimens. Here we used a genome-wide microarray-based approach to identify MGMT regulating miRNAs. Our screen unveiled three novel MGMT regulating miRNAs, miR-127-3p, miR-409-3p, and miR-124-3p, in addition to the previously identified miR-181d-5p. Transfection of these three novel miRNAs into the T98G glioblastoma cell line suppressed MGMT mRNA and protein expression. However, their MGMT- suppressive effects are 30-50% relative that seen with miR-181d-5p transfection. In silico analyses of The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) revealed that miR-181d-5p is the only miRNA that consistently exhibited inverse correlation with MGMT mRNA expression. However, statistical models incorporating both miR-181d-5p and miR-409-3p expression better predict MGMT expression relative to models involving either miRNA alone. Our results confirmed miR-181d-5p as the key MGMT-regulating miRNA. Other MGMT regulating miRNAs, including the miR-409-3p identified in this report, modify the effect of miR-181d-5p on MGMT expression. MGMT expression is, thus, regulated by cooperative interaction between key MGMT-regulating miRNAs.
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Khalil
authors.affiliation: Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, University of Ferrara, Ferrara, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Fabbri
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Santangelo
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.
authors.forename: Valentino
authors.initials: V
authors.lastname: Bezzerri
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Cantù
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Di Gennaro
authors.affiliation: Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, University of Ferrara, Ferrara, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Finotti
authors.affiliation: Section of Pathology and Histology, University Hospital, Verona, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Ghimenton
authors.affiliation: Section of Pathology and Histology, University Hospital, Verona, Italy.
authors.forename: Albino
authors.initials: A
authors.lastname: Eccher
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Dechecchi
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.|Section of Pathology and Histology, University Hospital, Verona, Italy.|Applied Research on Cancer Network (ARC-NET), University and Hospital Trust, Verona, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Scarpa
authors.affiliation: Center for Theoretical and Applied Neuro-oncology, Moores Cancer Center, Department of Neurosurgery, University of California San Diego, San Diego, CA, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Hirshman
authors.affiliation: Center for Theoretical and Applied Neuro-oncology, Moores Cancer Center, Department of Neurosurgery, University of California San Diego, San Diego, CA, USA.
authors.forename: Clark
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine and Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Ferracin
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine and Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Negrini
authors.affiliation: Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, University of Ferrara, Ferrara, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Gambari
authors.affiliation: Department of Pathology and Diagnostics, Laboratory of Molecular Pathology, University Hospital, Verona, Italy.|Section of Pathology and Histology, University Hospital, Verona, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Cabrini
mesh_terms: D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism; D015254:DNA Modification Methylases / Q000096:biosynthesis* / Q000235:genetics; D045643:DNA Repair Enzymes / Q000096:biosynthesis* / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D005909:Glioblastoma / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C572367:MIRN409 microRNA, human; C540193:MIrn181 microRNA, human; D035683:MicroRNAs; D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes
keywords: MGMT; glioblastoma; miR-181d-5p; miR-409-3p