title: Exosomal miRNAs from Peritoneum Lavage Fluid as Potential Prognostic Biomarkers of Peritoneal Metastasis in Gastric Cancer.
abstract: Peritoneal metastasis is the most frequent type of recurrence in patients with gastric cancer (GC) and is associated with poor prognosis. Peritoneal lavage cytology, used to evaluate the risk of peritoneal metastasis, has low sensitivity. Here, we assessed the diagnostic potential of exosomal miRNA profiles in peritoneal fluid for the prediction of peritoneal dissemination in GC. Total RNA was extracted from exosomes isolated from six gastric malignant ascites (MA) samples, 24 peritoneal lavage fluid (PLF) samples, and culture supernatants (CM) of two human gastric carcinoma cell lines that differ in their potential for peritoneal metastasis. Expression of exosomal miRNAs was evaluated with Agilent Human miRNA microarrays and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The microarray analysis indicated a low variability in the number and signal intensity of miRNAs detected among the samples. In the six MA fluids, miR-21 showed the highest signal intensity. We identified five miRNAs (miR-1225-5p, miR-320c, miR-1202, miR-1207-5p, and miR-4270) with high expression in MA samples, the PLF of serosa-invasive GC, and the CM of a highly metastatic GC cell line; these candidate miRNA species appear to be related to peritoneal dissemination. Differential expression of miR-21, miR-320c, and miR-1225-5p was validated in the PLF of serosa-invasive and non-invasive GC by qRT-PCR and miR-21 and miR-1225-5p were confirmed to be associated with serosal invasion in GC. PLF can be used to profile the expression of exosomal miRNAs. Our findings suggest that miR-21 and miR-1225-5p may serve as biomarkers of peritoneal recurrence after curative GC resection, thus providing a novel approach to early diagnosis of peritoneal dissemination of GC.
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Tokuhisa
authors.affiliation: Department of Clinical Oncology, Yokohama City University Graduate school of Medicine, Yokohama, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ichikawa
authors.affiliation: Division of Molecular and Cellular Medicine, National Cancer Center Research Institute, Tokyo, Japan.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Kosaka
authors.affiliation: Division of Molecular and Cellular Medicine, National Cancer Center Research Institute, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ochiya
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yashiro
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kosaka
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Hirochika
authors.initials: H
authors.lastname: Makino
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Akiyama
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Chikara
authors.initials: C
authors.lastname: Kunisaki
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Endo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001202:Ascitic Fluid / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000235:genetics*; D045744:Cell Line, Tumor; D055354:Exosomes / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D020411:Oligonucleotide Array Sequence Analysis; D010533:Peritoneal Lavage; D010534:Peritoneal Neoplasms / Q000235:genetics* / Q000556:secondary; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; C586244:MIRN1225 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs