title: Downregulation of microRNA-100/microRNA-125b is associated with lymph node metastasis in early colorectal cancer with submucosal invasion.
abstract: A majority of early colorectal cancers (CRCs) with submucosal invasion undergo surgical operation, despite a very low incidence of lymph node metastasis. Our study aimed to identify microRNAs (miRNAs) specifically responsible for lymph node metastasis in submucosal CRCs. MicroRNA microarray analysis revealed that miR-100 and miR-125b expression levels were significantly lower in CRC tissues with lymph node metastases than in those without metastases. These results were validated by quantitative real-time PCR in a larger set of clinical samples. The transfection of a miR-100 or miR-125b inhibitor into colon cancer HCT116 cells significantly increased cell invasion, migration, and MMP activity. Conversely, overexpression of miR-100 or miR-125b mimics significantly attenuated all these activities but did not affect cell growth. To identify target mRNAs, we undertook a gene expression array analysis of miR-100-silenced HCT116 cells as well as negative control cells. The Ingenuity Pathway Analysis, TargetScan software analyses, and subsequent verification of mRNA expression by real-time PCR identified mammalian target of rapamycin (mTOR) and insulin-like growth factor 1 receptor (IGF1R) as direct, and Fas and X-linked inhibitor-of-apoptosis protein (XIAP) as indirect candidate targets for miR-100 involved in lymph node metastasis. Knockdown of each gene by siRNA significantly reduced the invasiveness of HCT116 cells. These data clearly show that downregulation of miR-100 and miR-125b is closely associated with lymph node metastasis in submucosal CRC through enhancement of invasion, motility, and MMP activity. In particular, miR-100 may promote metastasis by upregulating mTOR, IGF1R, Fas, and XIAP as targets. Thus, miR-100 and miR-125b may be novel biomarkers for lymph node metastasis of early CRCs with submucosal invasion.
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Fujino
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Takeishi
authors.affiliation: Department of Pathophysiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Kensei
authors.initials: K
authors.lastname: Nishida
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Okamoto
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Muguruma
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kitamura
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Fujimoto
authors.affiliation: Department of Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Higashijima
authors.affiliation: Department of Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Shimada
authors.affiliation: Department of Pathophysiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Rokutan
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Takayama
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology*; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D008207:Lymphatic Metastasis / Q000235:genetics; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D017526:Receptor, IGF Type 1; D017451:Receptors, Somatomedin / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000235:genetics; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000235:genetics; D019014:fas Receptor / Q000235:genetics
chemical_list: C491901:FAS protein, human; C000597236:IGF1R protein, human; C544266:MIRN100 microRNA, human; C531888:MIRN125 microRNA, human; D035683:MicroRNAs; D034741:RNA, Small Interfering; D017451:Receptors, Somatomedin; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D019014:fas Receptor; C546842:MTOR protein, human; D017526:Receptor, IGF Type 1; D058570:TOR Serine-Threonine Kinases; D020782:Matrix Metalloproteinases
keywords: Cancer invasion; colorectal cancer with submucosal invasion; lymph node metastasis; miR-100; miR-125b