title: Regulation of deoxycytidine kinase expression and sensitivity to gemcitabine by micro-RNA 330 and promoter methylation in cancer cells.
abstract: Deoxycytidine kinase (dCK) is essential for phosphorylation of natural deoxynucleosides and analogs, such as gemcitabine and cytarabine, two widely used anticancer compounds. Regulation of dCK is complex, including Ser-74 phosphorylation. We hypothesized that dCK could be regulated by two additional mechanisms: micro-RNA (miRNA) and promoter methylation. Methylation-specific PCR (MSP) revealed methylation of the 3' GC box in three out of six cancer cell lines. The 3' GC box is located at the dCK promoter region. The methylation status was related to dCK mRNA expression. TargetScan and miRanda prediction algorithms revealed several possible miRNAs targeting dCK and identified miR-330 (micro-RNA 330) as the one conserved between the human, the chimpanzee, and the rhesus monkey genomes. Expression of miR-330 in various colon and lung cancer cell lines, as measured by QRT-PCR, varied five-fold between samples and correlated with in-vitro gemcitabine resistance (R = 0.82, p = 0.04). Exposure to gemcitabine also appeared to influence miR-330 levels in these cell lines. Furthermore, in our cell line panel, miR-330 expression negatively correlated with dCK mRNA expression (R = 0.74), suggesting a role of miR-330 in post-transcriptional regulation of dCK. In conclusion, the 3' GC box and miR-330 may regulate dCK expression in cancer cells.
authors: Department of Medical Oncology, VU University Medical Center, Amsterdam, The Netherlands.
authors: Jasmina
authors: J
authors: Hodzic
authors: Elisa
authors: E
authors: Giovannetti
authors: Begoňa
authors: B
authors: Diosdado
authors: Begona Diosdado
authors: BD
authors: Calvo
authors: A D
authors: AD
authors: Adema
authors: G J
authors: GJ
authors: Peters
mesh_terms: D001482:Base Composition / Q000235:genetics; D001483:Base Sequence; D045744:Cell Line, Tumor; D019175:DNA Methylation / Q000187:drug effects / Q000235:genetics*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003842:Deoxycytidine Kinase / Q000235:genetics* / Q000378:metabolism; D004354:Drug Screening Assays, Antitumor; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000201:enzymology / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000093542:Gemcitabine
chemical_list: C570805:MIRN330 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D003841:Deoxycytidine; D003842:Deoxycytidine Kinase; D000093542:Gemcitabine