東 剣虹
   Department   Research Institutes and Facilities, Research Institutes and Facilities
   Position   Assistant Professor
Article types Original article
Language English
Peer review Peer reviewed
Title Downregulation of Plasma miR-215 in Chronic Myeloid Leukemia Patients with Successful Discontinuation of Imatinib.
Journal Formal name:International journal of molecular sciences
Abbreviation:Int J Mol Sci
ISSN code:(1422-0067)1422-0067(Linking)
Volume, Issue, Page 17(4),pp.570
Author and coauthor Ohyashiki Kazuma, Umezu Tomohiro, Katagiri Seiichiro, Kobayashi Chiaki, Azuma Kenko, Tauchi Tetsuzo, Okabe Seiichi, Fukuoka Yutaka, Ohyashiki Junko H
Publication date 2016/04
Summary Approximately 40% of chronic myeloid leukemia (CML) patients who discontinue imatinib (IM) therapy maintain undetectable minimal residual disease (UMRD) for more than one year (stopping IM (STOP-IM)). To determine a possible biomarker for STOP-IM CML, we examined plasma miRNA expression in CML patients who were able to discontinue IM. We first screened candidate miRNAs in unselected STOP-IM patients, who had sustained UMRD after discontinuing IM for more than six months, in comparison with healthy volunteers, by using a TaqMan low-density array for plasma or exosomes. Exosomal miR-215 and plasma miR-215 were downregulated in the STOP-IM group compared to the control, indicating that the biological relevance of the plasma miR-215 level is equivalent to that of the exosomal level. Next, we performed real-time quantitative RT-PCR in 20 STOP-IM patients, 32 patients with UMRD on continued IM therapy (IM group) and 28 healthy volunteers. The plasma miRNA-215 level was significantly downregulated in the STOP-IM group (p < 0.0001); we determined the cut-off level and divided the IM group patients into two groups according to whether the plasma miR-215 was downregulated or not. The IM group patients with a low plasma miR-215 level had a significantly higher total IM intake, compared to the patients with elevated miR-215 levels (p = 0.0229). Functional annotation of miR-215 target genes estimated by the Database for Annotation, Visualization and Integrated Discovery (DAVID) bioinformatic tools involved cell cycle, mitosis, DNA repair and cell cycle checkpoint. Our study suggests a possible role of miR-215 in successful IM discontinuation.
DOI 10.3390/ijms17040570
PMID 27092489