Fumio Tanaka1,2, Shingo Takashima3, Yuji Nadatani3,4, Koji Otani3,4, Shuhei Hosomi3, Noriko Kamata3, Koichi Taira3, Yasuaki Nagami3, Tetsuya Tanigawa3, Shinya Fukumoto4, Toshio Watanabe3, Yoshiki Murakami5, Norifumi Kawada4,6, Yasuhiro Fujiwara3. 1. Department of Gastroenterology, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan. m2079981@med.osaka-cu.ac.jp. 2. Department of Premier Preventive Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan. m2079981@med.osaka-cu.ac.jp. 3. Department of Gastroenterology, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan. 4. Department of Premier Preventive Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan. 5. Department of Molecular Pathology, Tokyo Medical University, Tokyo, Japan. 6. Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
Abstract
BACKGROUND: MicroRNAs (miRNAs) in exosomes represent disease-specific profiles and are applied as biomarkers in oncology. However, in functional dyspepsia (FD), the role of exosomal miRNAs has not been fully elucidated. AIMS: To investigate exosomal miRNAs as potential biomarkers of FD using liquid biopsy. METHODS: This retrospective cohort study included 11 subjects with FD and 11 age- and sex-matched healthy controls (HCs). We collected gastric juice and isolated exosomal miRNAs. In a discovery cohort, expression levels of 2565 miRNAs were evaluated by 3D-Gene® microarray. miRNA expression profiles from exosomes of subjects with FD and HCs were compared by two normalization methods: (1) global normalization and (2) normalization by internal control. Subsequently, in a validation cohort, the expression levels of miRNAs were validated by quantitative reverse transcription PCR (RT-qPCR). RESULTS: Through microarray analysis using the two methods, we identified 39 miRNAs that were consistently and significantly downregulated in FD cases compared with those in HCs. Of these, 12 miRNAs (hsa-miR-933, hsa-miR-345-5p, hsa-miR-708-5p, hsa-miR-203a-3p, hsa-miR-619-5p, hsa-miR-4294, hsa-miR-4481, hsa-miR-196a-5p, hsa-miR-3918, hsa-miR-372-3p, hsa-miR-658, and hsa-miR-3654) were further validated by RT-qPCR. Our results indicated that hsa-miR-933 was significantly downregulated in FD compared with HCs (0.317 ± 0.205-fold, P = 0.0317). Furthermore, the expression level of hsa-miR-933 was negatively associated with dyspepsia score and the frequency of epigastric pain and/or burning (P < 0.01, r = - 0.835; P = 0.0280, r = - 0.688, respectively). CONCLUSIONS: Exosomal hsa-miR-933 in gastric juice could be a candidate biomarker for FD.
BACKGROUND: MicroRNAs (miRNAs) in exosomes represent disease-specific profiles and are applied as biomarkers in oncology. However, in functional dyspepsia (FD), the role of exosomal miRNAs has not been fully elucidated. AIMS: To investigate exosomal miRNAs as potential biomarkers of FD using liquid biopsy. METHODS: This retrospective cohort study included 11 subjects with FD and 11 age- and sex-matched healthy controls (HCs). We collected gastric juice and isolated exosomal miRNAs. In a discovery cohort, expression levels of 2565 miRNAs were evaluated by 3D-Gene® microarray. miRNA expression profiles from exosomes of subjects with FD and HCs were compared by two normalization methods: (1) global normalization and (2) normalization by internal control. Subsequently, in a validation cohort, the expression levels of miRNAs were validated by quantitative reverse transcription PCR (RT-qPCR). RESULTS: Through microarray analysis using the two methods, we identified 39 miRNAs that were consistently and significantly downregulated in FD cases compared with those in HCs. Of these, 12 miRNAs (hsa-miR-933, hsa-miR-345-5p, hsa-miR-708-5p, hsa-miR-203a-3p, hsa-miR-619-5p, hsa-miR-4294, hsa-miR-4481, hsa-miR-196a-5p, hsa-miR-3918, hsa-miR-372-3p, hsa-miR-658, and hsa-miR-3654) were further validated by RT-qPCR. Our results indicated that hsa-miR-933 was significantly downregulated in FD compared with HCs (0.317 ± 0.205-fold, P = 0.0317). Furthermore, the expression level of hsa-miR-933 was negatively associated with dyspepsia score and the frequency of epigastric pain and/or burning (P < 0.01, r = - 0.835; P = 0.0280, r = - 0.688, respectively). CONCLUSIONS: Exosomal hsa-miR-933 in gastric juice could be a candidate biomarker for FD.