title: Specific alterations of microRNA transcriptome and global network structure in colorectal carcinoma after cetuximab treatment.
abstract: The relationship between therapeutic response and modifications of microRNA (miRNA) transcriptome in colorectal cancer (CRC) remains unknown. We investigated this issue by profiling the expression of 667 miRNAs in 2 human CRC cell lines, one sensitive and the other resistant to cetuximab (Caco-2 and HCT-116, respectively), through TaqMan real-time PCR. Caco-2 and HCT-116 expressed different sets of miRNAs after treatment. Specifically, 21 and 22 miRNAs were differentially expressed in Caco-2 or HCT-116, respectively (t test, P < 0.01). By testing the expression of differentially expressed miRNAs in CRC patients, we found that miR-146b-3p and miR-486-5p are more abundant in K-ras-mutated samples with respect to wild-type ones (Wilcoxon test, P < 0.05). Sixty-seven percent of differentially expressed miRNAs were involved in cancer, including CRC, whereas 19 miRNA targets had been previously reported to be involved in the cetuximab pathway and CRC. We identified 25 transcription factors putatively controlling these miRNAs, 11 of which have been already reported to be involved in CRC. On the basis of these data, we suggest that the downregulation of let-7b and let-7e (targeting K-ras) and the upregulation of miR-17* (a CRC marker) could be considered as candidate molecular markers of cetuximab resistance. Global network functional analysis (based on miRNA targets) showed a significant overrepresentation of cancer-related biological processes and networks centered on critical nodes involved in epidermal growth factor receptor internalization and ubiquitin-mediated degradation. The identification of miRNAs, whose expression is linked to the efficacy of therapy, should allow the ability to predict the response of patients to treatment and possibly lead to a better understanding of the molecular mechanisms of drug response.
authors.affiliation: Dipartimento di Scienze BioMediche, Sezione di Biologia Generale, Biologia Cellulare, Genetica Molecolare, Unità di BioMedicina Molecolare Genomica e dei Sistemi Complessi, Genetica, Biologia Computazionale G Sichel, 95123 Catania, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ragusa
authors.forename: Alessandra
authors.initials: A
authors.lastname: Majorana
authors.forename: Luisa
authors.initials: L
authors.lastname: Statello
authors.forename: Marco
authors.initials: M
authors.lastname: Maugeri
authors.forename: Loredana
authors.initials: L
authors.lastname: Salito
authors.forename: Davide
authors.initials: D
authors.lastname: Barbagallo
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Guglielmino
authors.forename: Laura R
authors.initials: LR
authors.lastname: Duro
authors.forename: Rosario
authors.initials: R
authors.lastname: Angelica
authors.forename: Rosario
authors.initials: R
authors.lastname: Caltabiano
authors.forename: Antonio
authors.initials: A
authors.lastname: Biondi
authors.forename: Maria
authors.initials: M
authors.lastname: Di Vita
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Privitera
authors.forename: Marina
authors.initials: M
authors.lastname: Scalia
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cappellani
authors.forename: Enrico
authors.initials: E
authors.lastname: Vasquez
authors.forename: Salvatore
authors.initials: S
authors.lastname: Lanzafame
authors.forename: Francesco
authors.initials: F
authors.lastname: Basile
authors.forename: Cinzia
authors.initials: C
authors.lastname: Di Pietro
authors.forename: Michele
authors.initials: M
authors.lastname: Purrello
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001665:Binding Sites; D018938:Caco-2 Cells; D000068818:Cetuximab; D016000:Cluster Analysis; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D017124:Conserved Sequence / Q000235:genetics; D004354:Drug Screening Assays, Antitumor; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D053263:Gene Regulatory Networks / Q000235:genetics*; D015894:Genome, Human / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D000077544:Panitumumab; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D018631:ras Proteins / Q000235:genetics
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; C117307:KRAS protein, human; D035683:MicroRNAs; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D000077544:Panitumumab; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab