Open AccessDownregulation of micro RNA ‐100/micro RNA ‐125b is associated with lymph node metastasis in early colorectal cancer with submucosal invasion
Author(s) -
Fujino Yasuteru,
Takeishi Shunsaku,
Nishida Kensei,
Okamoto Koichi,
Muguruma Naoki,
Kimura Tetsuo,
Kitamura Shinji,
Miyamoto Hiroshi,
Fujimoto Akiko,
Higashijima Jun,
Shimada Mitsuo,
Rokutan Kazuhito,
Takayama Tetsuji
Publication year - 2017
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/cas.13152
Subject(s) - gene knockdown , downregulation and upregulation , cancer research , colorectal cancer , metastasis , rna , lymph node , microrna , small interfering rna , medicine , biology , cancer , pathology , apoptosis , gene , biochemistry
A majority of early colorectal cancers ( CRC s) with submucosal invasion undergo surgical operation, despite a very low incidence of lymph node metastasis. Our study aimed to identify micro RNA s (mi RNA s) specifically responsible for lymph node metastasis in submucosal CRC s. Micro RNA 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 HCT 116 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 m RNA s, we undertook a gene expression array analysis of miR‐100‐silenced HCT 116 cells as well as negative control cells. The Ingenuity Pathway Analysis, TargetScan software analyses, and subsequent verification of m RNA expression by real‐time PCR identified mammalian target of rapamycin (m TOR ) and insulin‐like growth factor 1 receptor ( IGF 1R) 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 si RNA significantly reduced the invasiveness of HCT 116 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 m TOR , IGF 1R, Fas, and XIAP as targets. Thus, miR‐100 and miR‐125b may be novel biomarkers for lymph node metastasis of early CRC s with submucosal invasion.