Circulating microRNAs in plasma of patients with gastric cancers.
BACKGROUND
We examined plasma microRNA (miRNA) concentrations from patients with gastric cancers (GCs) to assess their clinical application for diagnosing and monitoring diseases.


METHODS
We initially investigated the appropriateness of plasma miRNA assay, and then compared plasma miRNA results with the expressions in cancer tissues from eight GC patients, and also compared plasma miRNAs between pre- and post-operative paired samples from 10 GC patients. Then, plasma miRNAs (miR-17-5p, miR-21, miR-106a, miR-106b and let-7a) were analysed in 69 GC patients and 30 healthy volunteers in total.


RESULTS
The initial analysis showed that miRNAs were stable and detectable in all plasma samples, and the plasma miRNA levels reflected the tumour miRNAs in most cases. The levels of these miRNAs were significantly reduced in post-operative samples. In large-scale analysis, the plasma concentrations of miRNAs (miR-17-5p, miR-21, miR-106a, miR-106b) were significantly higher in GC patients than controls (P=0.05, 0.006, 0.008 and <0.001 respectively), whereas let-7a was lower in GC patients (P=0.002). The values of the area under the receiver-operating characteristic curve were 0.721 for the miR-106b assay and 0.879 for the miR-106a/let-7a ratio assay.


CONCLUSIONS
Detection of circulating miRNAs might provide new complementary tumour markers for GC.
Tsujiura
M
M
Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachihirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
Ichikawa
D
D
Komatsu
S
S
Shiozaki
A
A
Takeshita
H
H
Kosuga
T
T
Konishi
H
H
Morimura
R
R
Deguchi
K
K
Fujiwara
H
H
Okamoto
K
K
Otsuji
E
E
D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D035683:MicroRNAs / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000097:blood* / Q000175:diagnosis
D014408:Biomarkers, Tumor; D035683:MicroRNAs